Series comparison

The following changes since commit ffd454c67e38cc6df792733ebc5d967eee28ac0d:

Merge tag 'pull-vfio-20240107' of https://github.com/legoater/qemu into staging (2024-01-08 10:28:42 +0000)

are available in the Git repository at:

https://gitlab.com/stefanha/qemu.git tags/block-pull-request

for you to fetch changes up to 0b2675c473f68f13bc5ca1dd1c43ce421542e7b8:

Rename "QEMU global mutex" to "BQL" in comments and docs (2024-01-08 10:45:43 -0500)

----------------------------------------------------------------
Pull request

----------------------------------------------------------------

Philippe Mathieu-Daudé (1):
  iothread: Remove unused Error** argument in aio_context_set_aio_params

Stefan Hajnoczi (5):
  system/cpus: rename qemu_mutex_lock_iothread() to bql_lock()
  qemu/main-loop: rename QEMU_IOTHREAD_LOCK_GUARD to BQL_LOCK_GUARD
  qemu/main-loop: rename qemu_cond_wait_iothread() to
    qemu_cond_wait_bql()
  Replace "iothread lock" with "BQL" in comments
  Rename "QEMU global mutex" to "BQL" in comments and docs

-- 
2.43.0

From: Philippe Mathieu-Daudé <philmd@linaro.org>

aio_context_set_aio_params() doesn't use its undocumented
Error** argument. Remove it to simplify.

Note this removes a use of "unchecked Error**" in
iothread_set_aio_context_params().

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-ID: <20231120171806.19361-1-philmd@linaro.org>
---
 include/block/aio.h | 3 +--
 iothread.c          | 3 +--
 util/aio-posix.c    | 3 +--
 util/aio-win32.c    | 3 +--
 util/main-loop.c    | 5 +----
 5 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/include/block/aio.h b/include/block/aio.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -XXX,XX +XXX,XX @@ void aio_context_set_poll_params(AioContext *ctx, int64_t max_ns,
  * @max_batch: maximum number of requests in a batch, 0 means that the
  *             engine will use its default
  */
-void aio_context_set_aio_params(AioContext *ctx, int64_t max_batch,
-                                Error **errp);
+void aio_context_set_aio_params(AioContext *ctx, int64_t max_batch);
 
 /**
  * aio_context_set_thread_pool_params:
diff --git a/iothread.c b/iothread.c
index XXXXXXX..XXXXXXX 100644
--- a/iothread.c
+++ b/iothread.c
@@ -XXX,XX +XXX,XX @@ static void iothread_set_aio_context_params(EventLoopBase *base, Error **errp)
     }
 
     aio_context_set_aio_params(iothread->ctx,
-                               iothread->parent_obj.aio_max_batch,
-                               errp);
+                               iothread->parent_obj.aio_max_batch);
 
     aio_context_set_thread_pool_params(iothread->ctx, base->thread_pool_min,
                                        base->thread_pool_max, errp);
diff --git a/util/aio-posix.c b/util/aio-posix.c
index XXXXXXX..XXXXXXX 100644
--- a/util/aio-posix.c
+++ b/util/aio-posix.c
@@ -XXX,XX +XXX,XX @@ void aio_context_set_poll_params(AioContext *ctx, int64_t max_ns,
     aio_notify(ctx);
 }
 
-void aio_context_set_aio_params(AioContext *ctx, int64_t max_batch,
-                                Error **errp)
+void aio_context_set_aio_params(AioContext *ctx, int64_t max_batch)
 {
     /*
      * No thread synchronization here, it doesn't matter if an incorrect value
diff --git a/util/aio-win32.c b/util/aio-win32.c
index XXXXXXX..XXXXXXX 100644
--- a/util/aio-win32.c
+++ b/util/aio-win32.c
@@ -XXX,XX +XXX,XX @@ void aio_context_set_poll_params(AioContext *ctx, int64_t max_ns,
     }
 }
 
-void aio_context_set_aio_params(AioContext *ctx, int64_t max_batch,
-                                Error **errp)
+void aio_context_set_aio_params(AioContext *ctx, int64_t max_batch)
 {
 }
diff --git a/util/main-loop.c b/util/main-loop.c
index XXXXXXX..XXXXXXX 100644
--- a/util/main-loop.c
+++ b/util/main-loop.c
@@ -XXX,XX +XXX,XX @@ static void main_loop_update_params(EventLoopBase *base, Error **errp)
         return;
     }
 
-    aio_context_set_aio_params(qemu_aio_context, base->aio_max_batch, errp);
-    if (*errp) {
-        return;
-    }
+    aio_context_set_aio_params(qemu_aio_context, base->aio_max_batch);
 
     aio_context_set_thread_pool_params(qemu_aio_context, base->thread_pool_min,
                                        base->thread_pool_max, errp);
-- 
2.43.0

The Big QEMU Lock (BQL) has many names and they are confusing. The
actual QemuMutex variable is called qemu_global_mutex but it's commonly
referred to as the BQL in discussions and some code comments. The
locking APIs, however, are called qemu_mutex_lock_iothread() and
qemu_mutex_unlock_iothread().

The "iothread" name is historic and comes from when the main thread was
split into into KVM vcpu threads and the "iothread" (now called the main
loop thread). I have contributed to the confusion myself by introducing
a separate --object iothread, a separate concept unrelated to the BQL.

The "iothread" name is no longer appropriate for the BQL. Rename the
locking APIs to:
- void bql_lock(void)
- void bql_unlock(void)
- bool bql_locked(void)

There are more APIs with "iothread" in their names. Subsequent patches
will rename them. There are also comments and documentation that will be
updated in later patches.

diff --git a/include/block/aio-wait.h b/include/block/aio-wait.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/aio-wait.h
+++ b/include/block/aio-wait.h
@@ -XXX,XX +XXX,XX @@ static inline bool in_aio_context_home_thread(AioContext *ctx)
     }
 
     if (ctx == qemu_get_aio_context()) {
-        return qemu_mutex_iothread_locked();
+        return bql_locked();
     } else {
         return false;
     }
diff --git a/include/qemu/main-loop.h b/include/qemu/main-loop.h
index XXXXXXX..XXXXXXX 100644
--- a/include/qemu/main-loop.h
+++ b/include/qemu/main-loop.h
@@ -XXX,XX +XXX,XX @@ GSource *iohandler_get_g_source(void);
 AioContext *iohandler_get_aio_context(void);
 
 /**
- * qemu_mutex_iothread_locked: Return lock status of the main loop mutex.
+ * bql_locked: Return lock status of the Big QEMU Lock (BQL)
  *
- * The main loop mutex is the coarsest lock in QEMU, and as such it
+ * The Big QEMU Lock (BQL) is the coarsest lock in QEMU, and as such it
  * must always be taken outside other locks.  This function helps
  * functions take different paths depending on whether the current
- * thread is running within the main loop mutex.
+ * thread is running within the BQL.
  *
  * This function should never be used in the block layer, because
  * unit tests, block layer tools and qemu-storage-daemon do not
  * have a BQL.
  * Please instead refer to qemu_in_main_thread().
  */
-bool qemu_mutex_iothread_locked(void);
+bool bql_locked(void);
 
 /**
  * qemu_in_main_thread: return whether it's possible to safely access
@@ -XXX,XX +XXX,XX @@ bool qemu_in_main_thread(void);
     } while (0)
 
 /**
- * qemu_mutex_lock_iothread: Lock the main loop mutex.
+ * bql_lock: Lock the Big QEMU Lock (BQL).
  *
- * This function locks the main loop mutex.  The mutex is taken by
+ * This function locks the Big QEMU Lock (BQL).  The lock is taken by
  * main() in vl.c and always taken except while waiting on
- * external events (such as with select).  The mutex should be taken
+ * external events (such as with select).  The lock should be taken
  * by threads other than the main loop thread when calling
  * qemu_bh_new(), qemu_set_fd_handler() and basically all other
  * functions documented in this file.
  *
- * NOTE: tools currently are single-threaded and qemu_mutex_lock_iothread
+ * NOTE: tools currently are single-threaded and bql_lock
  * is a no-op there.
  */
-#define qemu_mutex_lock_iothread()                      \
-    qemu_mutex_lock_iothread_impl(__FILE__, __LINE__)
-void qemu_mutex_lock_iothread_impl(const char *file, int line);
+#define bql_lock() bql_lock_impl(__FILE__, __LINE__)
+void bql_lock_impl(const char *file, int line);
 
 /**
- * qemu_mutex_unlock_iothread: Unlock the main loop mutex.
+ * bql_unlock: Unlock the Big QEMU Lock (BQL).
  *
- * This function unlocks the main loop mutex.  The mutex is taken by
+ * This function unlocks the Big QEMU Lock.  The lock is taken by
  * main() in vl.c and always taken except while waiting on
- * external events (such as with select).  The mutex should be unlocked
+ * external events (such as with select).  The lock should be unlocked
  * as soon as possible by threads other than the main loop thread,
  * because it prevents the main loop from processing callbacks,
  * including timers and bottom halves.
  *
- * NOTE: tools currently are single-threaded and qemu_mutex_unlock_iothread
+ * NOTE: tools currently are single-threaded and bql_unlock
  * is a no-op there.
  */
-void qemu_mutex_unlock_iothread(void);
+void bql_unlock(void);
 
 /**
  * QEMU_IOTHREAD_LOCK_GUARD
  *
- * Wrap a block of code in a conditional qemu_mutex_{lock,unlock}_iothread.
+ * Wrap a block of code in a conditional bql_{lock,unlock}.
  */
 typedef struct IOThreadLockAuto IOThreadLockAuto;
 
 static inline IOThreadLockAuto *qemu_iothread_auto_lock(const char *file,
                                                         int line)
 {
-    if (qemu_mutex_iothread_locked()) {
+    if (bql_locked()) {
         return NULL;
     }
-    qemu_mutex_lock_iothread_impl(file, line);
+    bql_lock_impl(file, line);
     /* Anything non-NULL causes the cleanup function to be called */
     return (IOThreadLockAuto *)(uintptr_t)1;
 }
 
 static inline void qemu_iothread_auto_unlock(IOThreadLockAuto *l)
 {
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(IOThreadLockAuto, qemu_iothread_auto_unlock)
diff --git a/include/qemu/thread.h b/include/qemu/thread.h
index XXXXXXX..XXXXXXX 100644
--- a/include/qemu/thread.h
+++ b/include/qemu/thread.h
@@ -XXX,XX +XXX,XX @@ typedef void (*QemuCondWaitFunc)(QemuCond *c, QemuMutex *m, const char *f,
 typedef bool (*QemuCondTimedWaitFunc)(QemuCond *c, QemuMutex *m, int ms,
                                       const char *f, int l);
 
-extern QemuMutexLockFunc qemu_bql_mutex_lock_func;
+extern QemuMutexLockFunc bql_mutex_lock_func;
 extern QemuMutexLockFunc qemu_mutex_lock_func;
 extern QemuMutexTrylockFunc qemu_mutex_trylock_func;
 extern QemuRecMutexLockFunc qemu_rec_mutex_lock_func;
diff --git a/accel/accel-blocker.c b/accel/accel-blocker.c
index XXXXXXX..XXXXXXX 100644
--- a/accel/accel-blocker.c
+++ b/accel/accel-blocker.c
@@ -XXX,XX +XXX,XX @@ void accel_blocker_init(void)
 
 void accel_ioctl_begin(void)
 {
-    if (likely(qemu_mutex_iothread_locked())) {
+    if (likely(bql_locked())) {
         return;
     }
 
@@ -XXX,XX +XXX,XX @@ void accel_ioctl_begin(void)
 
 void accel_ioctl_end(void)
 {
-    if (likely(qemu_mutex_iothread_locked())) {
+    if (likely(bql_locked())) {
         return;
     }
 
@@ -XXX,XX +XXX,XX @@ void accel_ioctl_end(void)
 
 void accel_cpu_ioctl_begin(CPUState *cpu)
 {
-    if (unlikely(qemu_mutex_iothread_locked())) {
+    if (unlikely(bql_locked())) {
         return;
     }
 
@@ -XXX,XX +XXX,XX @@ void accel_cpu_ioctl_begin(CPUState *cpu)
 
 void accel_cpu_ioctl_end(CPUState *cpu)
 {
-    if (unlikely(qemu_mutex_iothread_locked())) {
+    if (unlikely(bql_locked())) {
         return;
     }
 
@@ -XXX,XX +XXX,XX @@ void accel_ioctl_inhibit_begin(void)
      * We allow to inhibit only when holding the BQL, so we can identify
      * when an inhibitor wants to issue an ioctl easily.
      */
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
 
     /* Block further invocations of the ioctls outside the BQL.  */
     CPU_FOREACH(cpu) {
diff --git a/accel/dummy-cpus.c b/accel/dummy-cpus.c
index XXXXXXX..XXXXXXX 100644
--- a/accel/dummy-cpus.c
+++ b/accel/dummy-cpus.c
@@ -XXX,XX +XXX,XX @@ static void *dummy_cpu_thread_fn(void *arg)
 
     rcu_register_thread();
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     qemu_thread_get_self(cpu->thread);
     cpu->thread_id = qemu_get_thread_id();
     cpu->neg.can_do_io = true;
@@ -XXX,XX +XXX,XX @@ static void *dummy_cpu_thread_fn(void *arg)
     qemu_guest_random_seed_thread_part2(cpu->random_seed);
 
     do {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
 #ifndef _WIN32
         do {
             int sig;
@@ -XXX,XX +XXX,XX @@ static void *dummy_cpu_thread_fn(void *arg)
 #else
         qemu_sem_wait(&cpu->sem);
 #endif
-        qemu_mutex_lock_iothread();
+        bql_lock();
         qemu_wait_io_event(cpu);
     } while (!cpu->unplug);
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     rcu_unregister_thread();
     return NULL;
 }
diff --git a/accel/hvf/hvf-accel-ops.c b/accel/hvf/hvf-accel-ops.c
index XXXXXXX..XXXXXXX 100644
--- a/accel/hvf/hvf-accel-ops.c
+++ b/accel/hvf/hvf-accel-ops.c
@@ -XXX,XX +XXX,XX @@ static void *hvf_cpu_thread_fn(void *arg)
 
     rcu_register_thread();
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     qemu_thread_get_self(cpu->thread);
 
     cpu->thread_id = qemu_get_thread_id();
@@ -XXX,XX +XXX,XX @@ static void *hvf_cpu_thread_fn(void *arg)
 
     hvf_vcpu_destroy(cpu);
     cpu_thread_signal_destroyed(cpu);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     rcu_unregister_thread();
     return NULL;
 }
diff --git a/accel/kvm/kvm-accel-ops.c b/accel/kvm/kvm-accel-ops.c
index XXXXXXX..XXXXXXX 100644
--- a/accel/kvm/kvm-accel-ops.c
+++ b/accel/kvm/kvm-accel-ops.c
@@ -XXX,XX +XXX,XX @@ static void *kvm_vcpu_thread_fn(void *arg)
 
     rcu_register_thread();
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     qemu_thread_get_self(cpu->thread);
     cpu->thread_id = qemu_get_thread_id();
     cpu->neg.can_do_io = true;
@@ -XXX,XX +XXX,XX @@ static void *kvm_vcpu_thread_fn(void *arg)
 
     kvm_destroy_vcpu(cpu);
     cpu_thread_signal_destroyed(cpu);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     rcu_unregister_thread();
     return NULL;
 }
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index XXXXXXX..XXXXXXX 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -XXX,XX +XXX,XX @@ static void kvm_dirty_ring_flush(void)
      * should always be with BQL held, serialization is guaranteed.
      * However, let's be sure of it.
      */
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
     /*
      * First make sure to flush the hardware buffers by kicking all
      * vcpus out in a synchronous way.
@@ -XXX,XX +XXX,XX @@ static void *kvm_dirty_ring_reaper_thread(void *data)
         trace_kvm_dirty_ring_reaper("wakeup");
         r->reaper_state = KVM_DIRTY_RING_REAPER_REAPING;
 
-        qemu_mutex_lock_iothread();
+        bql_lock();
         kvm_dirty_ring_reap(s, NULL);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
 
         r->reaper_iteration++;
     }
@@ -XXX,XX +XXX,XX @@ int kvm_cpu_exec(CPUState *cpu)
         return EXCP_HLT;
     }
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     cpu_exec_start(cpu);
 
     do {
@@ -XXX,XX +XXX,XX @@ int kvm_cpu_exec(CPUState *cpu)
 
 #ifdef KVM_HAVE_MCE_INJECTION
         if (unlikely(have_sigbus_pending)) {
-            qemu_mutex_lock_iothread();
+            bql_lock();
             kvm_arch_on_sigbus_vcpu(cpu, pending_sigbus_code,
                                     pending_sigbus_addr);
             have_sigbus_pending = false;
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
         }
 #endif
 
@@ -XXX,XX +XXX,XX @@ int kvm_cpu_exec(CPUState *cpu)
              * still full.  Got kicked by KVM_RESET_DIRTY_RINGS.
              */
             trace_kvm_dirty_ring_full(cpu->cpu_index);
-            qemu_mutex_lock_iothread();
+            bql_lock();
             /*
              * We throttle vCPU by making it sleep once it exit from kernel
              * due to dirty ring full. In the dirtylimit scenario, reaping
@@ -XXX,XX +XXX,XX @@ int kvm_cpu_exec(CPUState *cpu)
             } else {
                 kvm_dirty_ring_reap(kvm_state, NULL);
             }
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             dirtylimit_vcpu_execute(cpu);
             ret = 0;
             break;
@@ -XXX,XX +XXX,XX @@ int kvm_cpu_exec(CPUState *cpu)
                 break;
             case KVM_SYSTEM_EVENT_CRASH:
                 kvm_cpu_synchronize_state(cpu);
-                qemu_mutex_lock_iothread();
+                bql_lock();
                 qemu_system_guest_panicked(cpu_get_crash_info(cpu));
-                qemu_mutex_unlock_iothread();
+                bql_unlock();
                 ret = 0;
                 break;
             default:
@@ -XXX,XX +XXX,XX @@ int kvm_cpu_exec(CPUState *cpu)
     } while (ret == 0);
 
     cpu_exec_end(cpu);
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     if (ret < 0) {
         cpu_dump_state(cpu, stderr, CPU_DUMP_CODE);
diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index XXXXXXX..XXXXXXX 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -XXX,XX +XXX,XX @@ static void cpu_exec_longjmp_cleanup(CPUState *cpu)
         tcg_ctx->gen_tb = NULL;
     }
 #endif
-    if (qemu_mutex_iothread_locked()) {
-        qemu_mutex_unlock_iothread();
+    if (bql_locked()) {
+        bql_unlock();
     }
     assert_no_pages_locked();
 }
@@ -XXX,XX +XXX,XX @@ static inline bool cpu_handle_halt(CPUState *cpu)
 #if defined(TARGET_I386)
         if (cpu->interrupt_request & CPU_INTERRUPT_POLL) {
             X86CPU *x86_cpu = X86_CPU(cpu);
-            qemu_mutex_lock_iothread();
+            bql_lock();
             apic_poll_irq(x86_cpu->apic_state);
             cpu_reset_interrupt(cpu, CPU_INTERRUPT_POLL);
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
         }
 #endif /* TARGET_I386 */
         if (!cpu_has_work(cpu)) {
@@ -XXX,XX +XXX,XX @@ static inline bool cpu_handle_exception(CPUState *cpu, int *ret)
 #else
         if (replay_exception()) {
             CPUClass *cc = CPU_GET_CLASS(cpu);
-            qemu_mutex_lock_iothread();
+            bql_lock();
             cc->tcg_ops->do_interrupt(cpu);
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             cpu->exception_index = -1;
 
             if (unlikely(cpu->singlestep_enabled)) {
@@ -XXX,XX +XXX,XX @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
 
     if (unlikely(qatomic_read(&cpu->interrupt_request))) {
         int interrupt_request;
-        qemu_mutex_lock_iothread();
+        bql_lock();
         interrupt_request = cpu->interrupt_request;
         if (unlikely(cpu->singlestep_enabled & SSTEP_NOIRQ)) {
             /* Mask out external interrupts for this step. */
@@ -XXX,XX +XXX,XX @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
         if (interrupt_request & CPU_INTERRUPT_DEBUG) {
             cpu->interrupt_request &= ~CPU_INTERRUPT_DEBUG;
             cpu->exception_index = EXCP_DEBUG;
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             return true;
         }
 #if !defined(CONFIG_USER_ONLY)
@@ -XXX,XX +XXX,XX @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
             cpu->interrupt_request &= ~CPU_INTERRUPT_HALT;
             cpu->halted = 1;
             cpu->exception_index = EXCP_HLT;
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             return true;
         }
 #if defined(TARGET_I386)
@@ -XXX,XX +XXX,XX @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
             cpu_svm_check_intercept_param(env, SVM_EXIT_INIT, 0, 0);
             do_cpu_init(x86_cpu);
             cpu->exception_index = EXCP_HALTED;
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             return true;
         }
 #else
         else if (interrupt_request & CPU_INTERRUPT_RESET) {
             replay_interrupt();
             cpu_reset(cpu);
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             return true;
         }
 #endif /* !TARGET_I386 */
@@ -XXX,XX +XXX,XX @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
                  */
                 if (unlikely(cpu->singlestep_enabled)) {
                     cpu->exception_index = EXCP_DEBUG;
-                    qemu_mutex_unlock_iothread();
+                    bql_unlock();
                     return true;
                 }
                 cpu->exception_index = -1;
@@ -XXX,XX +XXX,XX @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
         }
 
         /* If we exit via cpu_loop_exit/longjmp it is reset in cpu_exec */
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 
     /* Finally, check if we need to exit to the main loop.  */
diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
index XXXXXXX..XXXXXXX 100644
--- a/accel/tcg/cputlb.c
+++ b/accel/tcg/cputlb.c
@@ -XXX,XX +XXX,XX @@ static uint64_t do_ld_mmio_beN(CPUState *cpu, CPUTLBEntryFull *full,
     section = io_prepare(&mr_offset, cpu, full->xlat_section, attrs, addr, ra);
     mr = section->mr;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ret = int_ld_mmio_beN(cpu, full, ret_be, addr, size, mmu_idx,
                           type, ra, mr, mr_offset);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     return ret;
 }
@@ -XXX,XX +XXX,XX @@ static Int128 do_ld16_mmio_beN(CPUState *cpu, CPUTLBEntryFull *full,
     section = io_prepare(&mr_offset, cpu, full->xlat_section, attrs, addr, ra);
     mr = section->mr;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     a = int_ld_mmio_beN(cpu, full, ret_be, addr, size - 8, mmu_idx,
                         MMU_DATA_LOAD, ra, mr, mr_offset);
     b = int_ld_mmio_beN(cpu, full, ret_be, addr + size - 8, 8, mmu_idx,
                         MMU_DATA_LOAD, ra, mr, mr_offset + size - 8);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     return int128_make128(b, a);
 }
@@ -XXX,XX +XXX,XX @@ static uint64_t do_st_mmio_leN(CPUState *cpu, CPUTLBEntryFull *full,
     section = io_prepare(&mr_offset, cpu, full->xlat_section, attrs, addr, ra);
     mr = section->mr;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ret = int_st_mmio_leN(cpu, full, val_le, addr, size, mmu_idx,
                           ra, mr, mr_offset);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     return ret;
 }
@@ -XXX,XX +XXX,XX @@ static uint64_t do_st16_mmio_leN(CPUState *cpu, CPUTLBEntryFull *full,
     section = io_prepare(&mr_offset, cpu, full->xlat_section, attrs, addr, ra);
     mr = section->mr;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     int_st_mmio_leN(cpu, full, int128_getlo(val_le), addr, 8,
                     mmu_idx, ra, mr, mr_offset);
     ret = int_st_mmio_leN(cpu, full, int128_gethi(val_le), addr + 8,
                           size - 8, mmu_idx, ra, mr, mr_offset + 8);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     return ret;
 }
diff --git a/accel/tcg/tcg-accel-ops-icount.c b/accel/tcg/tcg-accel-ops-icount.c
index XXXXXXX..XXXXXXX 100644
--- a/accel/tcg/tcg-accel-ops-icount.c
+++ b/accel/tcg/tcg-accel-ops-icount.c
@@ -XXX,XX +XXX,XX @@ void icount_prepare_for_run(CPUState *cpu, int64_t cpu_budget)
          * We're called without the iothread lock, so must take it while
          * we're calling timer handlers.
          */
-        qemu_mutex_lock_iothread();
+        bql_lock();
         icount_notify_aio_contexts();
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 }
 
diff --git a/accel/tcg/tcg-accel-ops-mttcg.c b/accel/tcg/tcg-accel-ops-mttcg.c
index XXXXXXX..XXXXXXX 100644
--- a/accel/tcg/tcg-accel-ops-mttcg.c
+++ b/accel/tcg/tcg-accel-ops-mttcg.c
@@ -XXX,XX +XXX,XX @@ static void *mttcg_cpu_thread_fn(void *arg)
     rcu_add_force_rcu_notifier(&force_rcu.notifier);
     tcg_register_thread();
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     qemu_thread_get_self(cpu->thread);
 
     cpu->thread_id = qemu_get_thread_id();
@@ -XXX,XX +XXX,XX @@ static void *mttcg_cpu_thread_fn(void *arg)
     do {
         if (cpu_can_run(cpu)) {
             int r;
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             r = tcg_cpus_exec(cpu);
-            qemu_mutex_lock_iothread();
+            bql_lock();
             switch (r) {
             case EXCP_DEBUG:
                 cpu_handle_guest_debug(cpu);
@@ -XXX,XX +XXX,XX @@ static void *mttcg_cpu_thread_fn(void *arg)
                  */
                 break;
             case EXCP_ATOMIC:
-                qemu_mutex_unlock_iothread();
+                bql_unlock();
                 cpu_exec_step_atomic(cpu);
-                qemu_mutex_lock_iothread();
+                bql_lock();
             default:
                 /* Ignore everything else? */
                 break;
@@ -XXX,XX +XXX,XX @@ static void *mttcg_cpu_thread_fn(void *arg)
     } while (!cpu->unplug || cpu_can_run(cpu));
 
     tcg_cpus_destroy(cpu);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     rcu_remove_force_rcu_notifier(&force_rcu.notifier);
     rcu_unregister_thread();
     return NULL;
diff --git a/accel/tcg/tcg-accel-ops-rr.c b/accel/tcg/tcg-accel-ops-rr.c
index XXXXXXX..XXXXXXX 100644
--- a/accel/tcg/tcg-accel-ops-rr.c
+++ b/accel/tcg/tcg-accel-ops-rr.c
@@ -XXX,XX +XXX,XX @@ static void *rr_cpu_thread_fn(void *arg)
     rcu_add_force_rcu_notifier(&force_rcu);
     tcg_register_thread();
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     qemu_thread_get_self(cpu->thread);
 
     cpu->thread_id = qemu_get_thread_id();
@@ -XXX,XX +XXX,XX @@ static void *rr_cpu_thread_fn(void *arg)
         /* Only used for icount_enabled() */
         int64_t cpu_budget = 0;
 
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         replay_mutex_lock();
-        qemu_mutex_lock_iothread();
+        bql_lock();
 
         if (icount_enabled()) {
             int cpu_count = rr_cpu_count();
@@ -XXX,XX +XXX,XX @@ static void *rr_cpu_thread_fn(void *arg)
             if (cpu_can_run(cpu)) {
                 int r;
 
-                qemu_mutex_unlock_iothread();
+                bql_unlock();
                 if (icount_enabled()) {
                     icount_prepare_for_run(cpu, cpu_budget);
                 }
@@ -XXX,XX +XXX,XX @@ static void *rr_cpu_thread_fn(void *arg)
                 if (icount_enabled()) {
                     icount_process_data(cpu);
                 }
-                qemu_mutex_lock_iothread();
+                bql_lock();
 
                 if (r == EXCP_DEBUG) {
                     cpu_handle_guest_debug(cpu);
                     break;
                 } else if (r == EXCP_ATOMIC) {
-                    qemu_mutex_unlock_iothread();
+                    bql_unlock();
                     cpu_exec_step_atomic(cpu);
-                    qemu_mutex_lock_iothread();
+                    bql_lock();
                     break;
                 }
             } else if (cpu->stop) {
diff --git a/accel/tcg/tcg-accel-ops.c b/accel/tcg/tcg-accel-ops.c
index XXXXXXX..XXXXXXX 100644
--- a/accel/tcg/tcg-accel-ops.c
+++ b/accel/tcg/tcg-accel-ops.c
@@ -XXX,XX +XXX,XX @@ static void tcg_cpu_reset_hold(CPUState *cpu)
 /* mask must never be zero, except for A20 change call */
 void tcg_handle_interrupt(CPUState *cpu, int mask)
 {
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
 
     cpu->interrupt_request |= mask;
 
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index XXXXXXX..XXXXXXX 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -XXX,XX +XXX,XX @@ void cpu_io_recompile(CPUState *cpu, uintptr_t retaddr)
 
 void cpu_interrupt(CPUState *cpu, int mask)
 {
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
     cpu->interrupt_request |= mask;
     qatomic_set(&cpu->neg.icount_decr.u16.high, -1);
 }
diff --git a/cpu-common.c b/cpu-common.c
index XXXXXXX..XXXXXXX 100644
--- a/cpu-common.c
+++ b/cpu-common.c
@@ -XXX,XX +XXX,XX @@ void process_queued_cpu_work(CPUState *cpu)
              * BQL, so it goes to sleep; start_exclusive() is sleeping too, so
              * neither CPU can proceed.
              */
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             start_exclusive();
             wi->func(cpu, wi->data);
             end_exclusive();
-            qemu_mutex_lock_iothread();
+            bql_lock();
         } else {
             wi->func(cpu, wi->data);
         }
diff --git a/dump/dump.c b/dump/dump.c
index XXXXXXX..XXXXXXX 100644
--- a/dump/dump.c
+++ b/dump/dump.c
@@ -XXX,XX +XXX,XX @@ static int dump_cleanup(DumpState *s)
     s->guest_note = NULL;
     if (s->resume) {
         if (s->detached) {
-            qemu_mutex_lock_iothread();
+            bql_lock();
         }
         vm_start();
         if (s->detached) {
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
         }
     }
     migrate_del_blocker(&dump_migration_blocker);
diff --git a/hw/core/cpu-common.c b/hw/core/cpu-common.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/core/cpu-common.c
+++ b/hw/core/cpu-common.c
@@ -XXX,XX +XXX,XX @@ CPUState *cpu_create(const char *typename)
  * BQL here if we need to.  cpu_interrupt assumes it is held.*/
 void cpu_reset_interrupt(CPUState *cpu, int mask)
 {
-    bool need_lock = !qemu_mutex_iothread_locked();
+    bool need_lock = !bql_locked();
 
     if (need_lock) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
     }
     cpu->interrupt_request &= ~mask;
     if (need_lock) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 }
 
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -XXX,XX +XXX,XX @@ static bool vtd_switch_address_space(VTDAddressSpace *as)
 {
     bool use_iommu, pt;
     /* Whether we need to take the BQL on our own */
-    bool take_bql = !qemu_mutex_iothread_locked();
+    bool take_bql = !bql_locked();
 
     assert(as);
 
@@ -XXX,XX +XXX,XX @@ static bool vtd_switch_address_space(VTDAddressSpace *as)
      * it. We'd better make sure we have had it already, or, take it.
      */
     if (take_bql) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
     }
 
     /* Turn off first then on the other */
@@ -XXX,XX +XXX,XX @@ static bool vtd_switch_address_space(VTDAddressSpace *as)
     }
 
     if (take_bql) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 
     return use_iommu;
diff --git a/hw/i386/kvm/xen_evtchn.c b/hw/i386/kvm/xen_evtchn.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/i386/kvm/xen_evtchn.c
+++ b/hw/i386/kvm/xen_evtchn.c
@@ -XXX,XX +XXX,XX @@ void xen_evtchn_set_callback_level(int level)
      * effect immediately. That just leaves interdomain loopback as the case
      * which uses the BH.
      */
-    if (!qemu_mutex_iothread_locked()) {
+    if (!bql_locked()) {
         qemu_bh_schedule(s->gsi_bh);
         return;
     }
@@ -XXX,XX +XXX,XX @@ int xen_evtchn_set_callback_param(uint64_t param)
      * We need the BQL because set_callback_pci_intx() may call into PCI code,
      * and because we may need to manipulate the old and new GSI levels.
      */
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
     qemu_mutex_lock(&s->port_lock);
 
     switch (type) {
@@ -XXX,XX +XXX,XX @@ static int close_port(XenEvtchnState *s, evtchn_port_t port,
     XenEvtchnPort *p = &s->port_table[port];
 
     /* Because it *might* be a PIRQ port */
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     switch (p->type) {
     case EVTCHNSTAT_closed:
@@ -XXX,XX +XXX,XX @@ int xen_evtchn_soft_reset(void)
         return -ENOTSUP;
     }
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     qemu_mutex_lock(&s->port_lock);
 
@@ -XXX,XX +XXX,XX @@ bool xen_evtchn_set_gsi(int gsi, int level)
     XenEvtchnState *s = xen_evtchn_singleton;
     int pirq;
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     if (!s || gsi < 0 || gsi >= IOAPIC_NUM_PINS) {
         return false;
@@ -XXX,XX +XXX,XX @@ void xen_evtchn_snoop_msi(PCIDevice *dev, bool is_msix, unsigned int vector,
         return;
     }
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     pirq = msi_pirq_target(addr, data);
 
@@ -XXX,XX +XXX,XX @@ int xen_evtchn_translate_pirq_msi(struct kvm_irq_routing_entry *route,
         return 1; /* Not a PIRQ */
     }
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     pirq = msi_pirq_target(address, data);
     if (!pirq || pirq >= s->nr_pirqs) {
@@ -XXX,XX +XXX,XX @@ bool xen_evtchn_deliver_pirq_msi(uint64_t address, uint32_t data)
         return false;
     }
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     pirq = msi_pirq_target(address, data);
     if (!pirq || pirq >= s->nr_pirqs) {
diff --git a/hw/i386/kvm/xen_overlay.c b/hw/i386/kvm/xen_overlay.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/i386/kvm/xen_overlay.c
+++ b/hw/i386/kvm/xen_overlay.c
@@ -XXX,XX +XXX,XX @@ int xen_overlay_map_shinfo_page(uint64_t gpa)
         return -ENOENT;
     }
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     if (s->shinfo_gpa) {
         /* If removing shinfo page, turn the kernel magic off first */
diff --git a/hw/i386/kvm/xen_xenstore.c b/hw/i386/kvm/xen_xenstore.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/i386/kvm/xen_xenstore.c
+++ b/hw/i386/kvm/xen_xenstore.c
@@ -XXX,XX +XXX,XX @@ static void fire_watch_cb(void *opaque, const char *path, const char *token)
 {
     XenXenstoreState *s = opaque;
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     /*
      * If there's a response pending, we obviously can't scribble over
diff --git a/hw/intc/arm_gicv3_cpuif.c b/hw/intc/arm_gicv3_cpuif.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/intc/arm_gicv3_cpuif.c
+++ b/hw/intc/arm_gicv3_cpuif.c
@@ -XXX,XX +XXX,XX @@ void gicv3_cpuif_update(GICv3CPUState *cs)
     ARMCPU *cpu = ARM_CPU(cs->cpu);
     CPUARMState *env = &cpu->env;
 
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
 
     trace_gicv3_cpuif_update(gicv3_redist_affid(cs), cs->hppi.irq,
                              cs->hppi.grp, cs->hppi.prio);
diff --git a/hw/intc/s390_flic.c b/hw/intc/s390_flic.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/intc/s390_flic.c
+++ b/hw/intc/s390_flic.c
@@ -XXX,XX +XXX,XX @@ static int qemu_s390_clear_io_flic(S390FLICState *fs, uint16_t subchannel_id,
     QEMUS390FlicIO *cur, *next;
     uint8_t isc;
 
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
     if (!(flic->pending & FLIC_PENDING_IO)) {
         return 0;
     }
@@ -XXX,XX +XXX,XX @@ uint32_t qemu_s390_flic_dequeue_service(QEMUS390FLICState *flic)
 {
     uint32_t tmp;
 
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
     g_assert(flic->pending & FLIC_PENDING_SERVICE);
     tmp = flic->service_param;
     flic->service_param = 0;
@@ -XXX,XX +XXX,XX @@ QEMUS390FlicIO *qemu_s390_flic_dequeue_io(QEMUS390FLICState *flic, uint64_t cr6)
     QEMUS390FlicIO *io;
     uint8_t isc;
 
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
     if (!(flic->pending & CR6_TO_PENDING_IO(cr6))) {
         return NULL;
     }
@@ -XXX,XX +XXX,XX @@ QEMUS390FlicIO *qemu_s390_flic_dequeue_io(QEMUS390FLICState *flic, uint64_t cr6)
 
 void qemu_s390_flic_dequeue_crw_mchk(QEMUS390FLICState *flic)
 {
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
     g_assert(flic->pending & FLIC_PENDING_MCHK_CR);
     flic->pending &= ~FLIC_PENDING_MCHK_CR;
 }
@@ -XXX,XX +XXX,XX @@ static void qemu_s390_inject_service(S390FLICState *fs, uint32_t parm)
 {
     QEMUS390FLICState *flic = s390_get_qemu_flic(fs);
 
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
     /* multiplexing is good enough for sclp - kvm does it internally as well */
     flic->service_param |= parm;
     flic->pending |= FLIC_PENDING_SERVICE;
@@ -XXX,XX +XXX,XX @@ static void qemu_s390_inject_io(S390FLICState *fs, uint16_t subchannel_id,
     QEMUS390FLICState *flic = s390_get_qemu_flic(fs);
     QEMUS390FlicIO *io;
 
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
     io = g_new0(QEMUS390FlicIO, 1);
     io->id = subchannel_id;
     io->nr = subchannel_nr;
@@ -XXX,XX +XXX,XX @@ static void qemu_s390_inject_crw_mchk(S390FLICState *fs)
 {
     QEMUS390FLICState *flic = s390_get_qemu_flic(fs);
 
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
     flic->pending |= FLIC_PENDING_MCHK_CR;
 
     qemu_s390_flic_notify(FLIC_PENDING_MCHK_CR);
@@ -XXX,XX +XXX,XX @@ bool qemu_s390_flic_has_crw_mchk(QEMUS390FLICState *flic)
 
 bool qemu_s390_flic_has_any(QEMUS390FLICState *flic)
 {
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
     return !!flic->pending;
 }
 
@@ -XXX,XX +XXX,XX @@ static void qemu_s390_flic_reset(DeviceState *dev)
     QEMUS390FlicIO *cur, *next;
     int isc;
 
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
     flic->simm = 0;
     flic->nimm = 0;
     flic->pending = 0;
diff --git a/hw/misc/edu.c b/hw/misc/edu.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/misc/edu.c
+++ b/hw/misc/edu.c
@@ -XXX,XX +XXX,XX @@ static void *edu_fact_thread(void *opaque)
         smp_mb__after_rmw();
 
         if (qatomic_read(&edu->status) & EDU_STATUS_IRQFACT) {
-            qemu_mutex_lock_iothread();
+            bql_lock();
             edu_raise_irq(edu, FACT_IRQ);
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
         }
     }
 
diff --git a/hw/misc/imx6_src.c b/hw/misc/imx6_src.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/misc/imx6_src.c
+++ b/hw/misc/imx6_src.c
@@ -XXX,XX +XXX,XX @@ static void imx6_clear_reset_bit(CPUState *cpu, run_on_cpu_data data)
     struct SRCSCRResetInfo *ri = data.host_ptr;
     IMX6SRCState *s = ri->s;
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     s->regs[SRC_SCR] = deposit32(s->regs[SRC_SCR], ri->reset_bit, 1, 0);
     DPRINTF("reg[%s] <= 0x%" PRIx32 "\n",
diff --git a/hw/misc/imx7_src.c b/hw/misc/imx7_src.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/misc/imx7_src.c
+++ b/hw/misc/imx7_src.c
@@ -XXX,XX +XXX,XX @@ static void imx7_clear_reset_bit(CPUState *cpu, run_on_cpu_data data)
     struct SRCSCRResetInfo *ri = data.host_ptr;
     IMX7SRCState *s = ri->s;
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     s->regs[SRC_A7RCR0] = deposit32(s->regs[SRC_A7RCR0], ri->reset_bit, 1, 0);
 
diff --git a/hw/net/xen_nic.c b/hw/net/xen_nic.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/net/xen_nic.c
+++ b/hw/net/xen_nic.c
@@ -XXX,XX +XXX,XX @@ static bool net_tx_packets(struct XenNetDev *netdev)
     void *page;
     void *tmpbuf = NULL;
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     for (;;) {
         rc = netdev->tx_ring.req_cons;
@@ -XXX,XX +XXX,XX @@ static ssize_t net_rx_packet(NetClientState *nc, const uint8_t *buf, size_t size
     RING_IDX rc, rp;
     void *page;
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     if (xen_device_backend_get_state(&netdev->xendev) != XenbusStateConnected) {
         return -1;
@@ -XXX,XX +XXX,XX @@ static bool xen_netdev_connect(XenDevice *xendev, Error **errp)
     XenNetDev *netdev = XEN_NET_DEVICE(xendev);
     unsigned int port, rx_copy;
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     if (xen_device_frontend_scanf(xendev, "tx-ring-ref", "%u",
                                   &netdev->tx_ring_ref) != 1) {
@@ -XXX,XX +XXX,XX @@ static void xen_netdev_disconnect(XenDevice *xendev, Error **errp)
 
     trace_xen_netdev_disconnect(netdev->dev);
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     netdev->tx_ring.sring = NULL;
     netdev->rx_ring.sring = NULL;
diff --git a/hw/ppc/pegasos2.c b/hw/ppc/pegasos2.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/ppc/pegasos2.c
+++ b/hw/ppc/pegasos2.c
@@ -XXX,XX +XXX,XX @@ static void pegasos2_hypercall(PPCVirtualHypervisor *vhyp, PowerPCCPU *cpu)
     CPUPPCState *env = &cpu->env;
 
     /* The TCG path should also be holding the BQL at this point */
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
 
     if (FIELD_EX64(env->msr, MSR, PR)) {
         qemu_log_mask(LOG_GUEST_ERROR, "Hypercall made with MSR[PR]=1\n");
diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/ppc/ppc.c
+++ b/hw/ppc/ppc.c
@@ -XXX,XX +XXX,XX @@ void store_40x_dbcr0(CPUPPCState *env, uint32_t val)
 {
     PowerPCCPU *cpu = env_archcpu(env);
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     switch ((val >> 28) & 0x3) {
     case 0x0:
@@ -XXX,XX +XXX,XX @@ void store_40x_dbcr0(CPUPPCState *env, uint32_t val)
         break;
     }
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 /* PowerPC 40x internal IRQ controller */
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -XXX,XX +XXX,XX @@ static void emulate_spapr_hypercall(PPCVirtualHypervisor *vhyp,
     CPUPPCState *env = &cpu->env;
 
     /* The TCG path should also be holding the BQL at this point */
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
 
     g_assert(!vhyp_cpu_in_nested(cpu));
 
diff --git a/hw/ppc/spapr_rng.c b/hw/ppc/spapr_rng.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/ppc/spapr_rng.c
+++ b/hw/ppc/spapr_rng.c
@@ -XXX,XX +XXX,XX @@ static target_ulong h_random(PowerPCCPU *cpu, SpaprMachineState *spapr,
     while (hrdata.received < 8) {
         rng_backend_request_entropy(rngstate->backend, 8 - hrdata.received,
                                     random_recv, &hrdata);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         qemu_sem_wait(&hrdata.sem);
-        qemu_mutex_lock_iothread();
+        bql_lock();
     }
 
     qemu_sem_destroy(&hrdata.sem);
diff --git a/hw/ppc/spapr_softmmu.c b/hw/ppc/spapr_softmmu.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/ppc/spapr_softmmu.c
+++ b/hw/ppc/spapr_softmmu.c
@@ -XXX,XX +XXX,XX @@ static void *hpt_prepare_thread(void *opaque)
         pending->ret = H_NO_MEM;
     }
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     if (SPAPR_MACHINE(qdev_get_machine())->pending_hpt == pending) {
         /* Ready to go */
@@ -XXX,XX +XXX,XX @@ static void *hpt_prepare_thread(void *opaque)
         free_pending_hpt(pending);
     }
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     return NULL;
 }
 
diff --git a/hw/remote/mpqemu-link.c b/hw/remote/mpqemu-link.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/mpqemu-link.c
+++ b/hw/remote/mpqemu-link.c
@@ -XXX,XX +XXX,XX @@
  */
 bool mpqemu_msg_send(MPQemuMsg *msg, QIOChannel *ioc, Error **errp)
 {
-    bool iolock = qemu_mutex_iothread_locked();
+    bool drop_bql = bql_locked();
     bool iothread = qemu_in_iothread();
     struct iovec send[2] = {};
     int *fds = NULL;
@@ -XXX,XX +XXX,XX @@ bool mpqemu_msg_send(MPQemuMsg *msg, QIOChannel *ioc, Error **errp)
      * for IOThread case.
      * Also skip lock handling while in a co-routine in the main context.
      */
-    if (iolock && !iothread && !qemu_in_coroutine()) {
-        qemu_mutex_unlock_iothread();
+    if (drop_bql && !iothread && !qemu_in_coroutine()) {
+        bql_unlock();
     }
 
     if (!qio_channel_writev_full_all(ioc, send, G_N_ELEMENTS(send),
@@ -XXX,XX +XXX,XX @@ bool mpqemu_msg_send(MPQemuMsg *msg, QIOChannel *ioc, Error **errp)
         trace_mpqemu_send_io_error(msg->cmd, msg->size, nfds);
     }
 
-    if (iolock && !iothread && !qemu_in_coroutine()) {
+    if (drop_bql && !iothread && !qemu_in_coroutine()) {
         /* See above comment why skip locking here. */
-        qemu_mutex_lock_iothread();
+        bql_lock();
     }
 
     return ret;
@@ -XXX,XX +XXX,XX @@ static ssize_t mpqemu_read(QIOChannel *ioc, void *buf, size_t len, int **fds,
                            size_t *nfds, Error **errp)
 {
     struct iovec iov = { .iov_base = buf, .iov_len = len };
-    bool iolock = qemu_mutex_iothread_locked();
+    bool drop_bql = bql_locked();
     bool iothread = qemu_in_iothread();
     int ret = -1;
 
@@ -XXX,XX +XXX,XX @@ static ssize_t mpqemu_read(QIOChannel *ioc, void *buf, size_t len, int **fds,
      */
     assert(qemu_in_coroutine() || !iothread);
 
-    if (iolock && !iothread && !qemu_in_coroutine()) {
-        qemu_mutex_unlock_iothread();
+    if (drop_bql && !iothread && !qemu_in_coroutine()) {
+        bql_unlock();
     }
 
     ret = qio_channel_readv_full_all_eof(ioc, &iov, 1, fds, nfds, errp);
 
-    if (iolock && !iothread && !qemu_in_coroutine()) {
-        qemu_mutex_lock_iothread();
+    if (drop_bql && !iothread && !qemu_in_coroutine()) {
+        bql_lock();
     }
 
     return (ret <= 0) ? ret : iov.iov_len;
diff --git a/hw/remote/vfio-user-obj.c b/hw/remote/vfio-user-obj.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/vfio-user-obj.c
+++ b/hw/remote/vfio-user-obj.c
@@ -XXX,XX +XXX,XX @@ static int vfu_object_mr_rw(MemoryRegion *mr, uint8_t *buf, hwaddr offset,
         }
 
         if (release_lock) {
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             release_lock = false;
         }
 
diff --git a/hw/s390x/s390-skeys.c b/hw/s390x/s390-skeys.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/s390x/s390-skeys.c
+++ b/hw/s390x/s390-skeys.c
@@ -XXX,XX +XXX,XX @@ void qmp_dump_skeys(const char *filename, Error **errp)
         goto out;
     }
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
     guest_phys_blocks_init(&guest_phys_blocks);
     guest_phys_blocks_append(&guest_phys_blocks);
 
diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/migration/block-dirty-bitmap.c
+++ b/migration/block-dirty-bitmap.c
@@ -XXX,XX +XXX,XX @@ static void dirty_bitmap_state_pending(void *opaque,
     SaveBitmapState *dbms;
     uint64_t pending = 0;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     QSIMPLEQ_FOREACH(dbms, &s->dbms_list, entry) {
         uint64_t gran = bdrv_dirty_bitmap_granularity(dbms->bitmap);
@@ -XXX,XX +XXX,XX @@ static void dirty_bitmap_state_pending(void *opaque,
         pending += DIV_ROUND_UP(sectors * BDRV_SECTOR_SIZE, gran);
     }
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     trace_dirty_bitmap_state_pending(pending);
 
diff --git a/migration/block.c b/migration/block.c
index XXXXXXX..XXXXXXX 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -XXX,XX +XXX,XX @@ static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds)
     int64_t count;
 
     if (bmds->shared_base) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
         /* Skip unallocated sectors; intentionally treats failure or
          * partial sector as an allocated sector */
         while (cur_sector < total_sectors &&
@@ -XXX,XX +XXX,XX @@ static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds)
             }
             cur_sector += count >> BDRV_SECTOR_BITS;
         }
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 
     if (cur_sector >= total_sectors) {
@@ -XXX,XX +XXX,XX @@ static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds)
      * I/O runs in the main loop AioContext (see
      * qemu_get_current_aio_context()).
      */
-    qemu_mutex_lock_iothread();
+    bql_lock();
     bdrv_reset_dirty_bitmap(bmds->dirty_bitmap, cur_sector * BDRV_SECTOR_SIZE,
                             nr_sectors * BDRV_SECTOR_SIZE);
     blk->aiocb = blk_aio_preadv(bb, cur_sector * BDRV_SECTOR_SIZE, &blk->qiov,
                                 0, blk_mig_read_cb, blk);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     bmds->cur_sector = cur_sector + nr_sectors;
     return (bmds->cur_sector >= total_sectors);
@@ -XXX,XX +XXX,XX @@ static int block_save_iterate(QEMUFile *f, void *opaque)
             /* Always called with iothread lock taken for
              * simplicity, block_save_complete also calls it.
              */
-            qemu_mutex_lock_iothread();
+            bql_lock();
             ret = blk_mig_save_dirty_block(f, 1);
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
         }
         if (ret < 0) {
             return ret;
@@ -XXX,XX +XXX,XX @@ static void block_state_pending(void *opaque, uint64_t *must_precopy,
     /* Estimate pending number of bytes to send */
     uint64_t pending;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     pending = get_remaining_dirty();
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     blk_mig_lock();
     pending += block_mig_state.submitted * BLK_MIG_BLOCK_SIZE +
diff --git a/migration/colo.c b/migration/colo.c
index XXXXXXX..XXXXXXX 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -XXX,XX +XXX,XX @@ static int colo_do_checkpoint_transaction(MigrationState *s,
     qio_channel_io_seek(QIO_CHANNEL(bioc), 0, 0, NULL);
     bioc->usage = 0;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     if (failover_get_state() != FAILOVER_STATUS_NONE) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         goto out;
     }
     vm_stop_force_state(RUN_STATE_COLO);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     trace_colo_vm_state_change("run", "stop");
     /*
      * Failover request bh could be called after vm_stop_force_state(),
@@ -XXX,XX +XXX,XX @@ static int colo_do_checkpoint_transaction(MigrationState *s,
     if (failover_get_state() != FAILOVER_STATUS_NONE) {
         goto out;
     }
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     replication_do_checkpoint_all(&local_err);
     if (local_err) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         goto out;
     }
 
     colo_send_message(s->to_dst_file, COLO_MESSAGE_VMSTATE_SEND, &local_err);
     if (local_err) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         goto out;
     }
     /* Note: device state is saved into buffer */
     ret = qemu_save_device_state(fb);
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     if (ret < 0) {
         goto out;
     }
@@ -XXX,XX +XXX,XX @@ static int colo_do_checkpoint_transaction(MigrationState *s,
 
     ret = 0;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     vm_start();
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     trace_colo_vm_state_change("stop", "run");
 
 out:
@@ -XXX,XX +XXX,XX @@ static void colo_process_checkpoint(MigrationState *s)
     fb = qemu_file_new_output(QIO_CHANNEL(bioc));
     object_unref(OBJECT(bioc));
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     replication_start_all(REPLICATION_MODE_PRIMARY, &local_err);
     if (local_err) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         goto out;
     }
 
     vm_start();
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     trace_colo_vm_state_change("stop", "run");
 
     timer_mod(s->colo_delay_timer, qemu_clock_get_ms(QEMU_CLOCK_HOST) +
@@ -XXX,XX +XXX,XX @@ out:
 
 void migrate_start_colo_process(MigrationState *s)
 {
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     qemu_event_init(&s->colo_checkpoint_event, false);
     s->colo_delay_timer =  timer_new_ms(QEMU_CLOCK_HOST,
                                 colo_checkpoint_notify, s);
 
     qemu_sem_init(&s->colo_exit_sem, 0);
     colo_process_checkpoint(s);
-    qemu_mutex_lock_iothread();
+    bql_lock();
 }
 
 static void colo_incoming_process_checkpoint(MigrationIncomingState *mis,
@@ -XXX,XX +XXX,XX @@ static void colo_incoming_process_checkpoint(MigrationIncomingState *mis,
     Error *local_err = NULL;
     int ret;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     vm_stop_force_state(RUN_STATE_COLO);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     trace_colo_vm_state_change("run", "stop");
 
     /* FIXME: This is unnecessary for periodic checkpoint mode */
@@ -XXX,XX +XXX,XX @@ static void colo_incoming_process_checkpoint(MigrationIncomingState *mis,
         return;
     }
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     cpu_synchronize_all_states();
     ret = qemu_loadvm_state_main(mis->from_src_file, mis);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     if (ret < 0) {
         error_setg(errp, "Load VM's live state (ram) error");
@@ -XXX,XX +XXX,XX @@ static void colo_incoming_process_checkpoint(MigrationIncomingState *mis,
         return;
     }
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     vmstate_loading = true;
     colo_flush_ram_cache();
     ret = qemu_load_device_state(fb);
     if (ret < 0) {
         error_setg(errp, "COLO: load device state failed");
         vmstate_loading = false;
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         return;
     }
 
@@ -XXX,XX +XXX,XX @@ static void colo_incoming_process_checkpoint(MigrationIncomingState *mis,
     if (local_err) {
         error_propagate(errp, local_err);
         vmstate_loading = false;
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         return;
     }
 
@@ -XXX,XX +XXX,XX @@ static void colo_incoming_process_checkpoint(MigrationIncomingState *mis,
     if (local_err) {
         error_propagate(errp, local_err);
         vmstate_loading = false;
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         return;
     }
     /* Notify all filters of all NIC to do checkpoint */
@@ -XXX,XX +XXX,XX @@ static void colo_incoming_process_checkpoint(MigrationIncomingState *mis,
     if (local_err) {
         error_propagate(errp, local_err);
         vmstate_loading = false;
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         return;
     }
 
     vmstate_loading = false;
     vm_start();
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     trace_colo_vm_state_change("stop", "run");
 
     if (failover_get_state() == FAILOVER_STATUS_RELAUNCH) {
@@ -XXX,XX +XXX,XX @@ static void *colo_process_incoming_thread(void *opaque)
     fb = qemu_file_new_input(QIO_CHANNEL(bioc));
     object_unref(OBJECT(bioc));
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     replication_start_all(REPLICATION_MODE_SECONDARY, &local_err);
     if (local_err) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         goto out;
     }
     vm_start();
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     trace_colo_vm_state_change("stop", "run");
 
     colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_READY,
@@ -XXX,XX +XXX,XX @@ int coroutine_fn colo_incoming_co(void)
     Error *local_err = NULL;
     QemuThread th;
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     if (!migration_incoming_colo_enabled()) {
         return 0;
@@ -XXX,XX +XXX,XX @@ int coroutine_fn colo_incoming_co(void)
     qemu_coroutine_yield();
     mis->colo_incoming_co = NULL;
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     /* Wait checkpoint incoming thread exit before free resource */
     qemu_thread_join(&th);
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     /* We hold the global iothread lock, so it is safe here */
     colo_release_ram_cache();
diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
index XXXXXXX..XXXXXXX 100644
--- a/migration/dirtyrate.c
+++ b/migration/dirtyrate.c
@@ -XXX,XX +XXX,XX @@ static int64_t do_calculate_dirtyrate(DirtyPageRecord dirty_pages,
 
 void global_dirty_log_change(unsigned int flag, bool start)
 {
-    qemu_mutex_lock_iothread();
+    bql_lock();
     if (start) {
         memory_global_dirty_log_start(flag);
     } else {
         memory_global_dirty_log_stop(flag);
     }
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 /*
@@ -XXX,XX +XXX,XX @@ void global_dirty_log_change(unsigned int flag, bool start)
  */
 static void global_dirty_log_sync(unsigned int flag, bool one_shot)
 {
-    qemu_mutex_lock_iothread();
+    bql_lock();
     memory_global_dirty_log_sync(false);
     if (one_shot) {
         memory_global_dirty_log_stop(flag);
     }
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 static DirtyPageRecord *vcpu_dirty_stat_alloc(VcpuStat *stat)
@@ -XXX,XX +XXX,XX @@ static void calculate_dirtyrate_dirty_bitmap(struct DirtyRateConfig config)
     int64_t start_time;
     DirtyPageRecord dirty_pages;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     memory_global_dirty_log_start(GLOBAL_DIRTY_DIRTY_RATE);
 
     /*
@@ -XXX,XX +XXX,XX @@ static void calculate_dirtyrate_dirty_bitmap(struct DirtyRateConfig config)
      * KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE cap is enabled.
      */
     dirtyrate_manual_reset_protect();
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     record_dirtypages_bitmap(&dirty_pages, true);
 
diff --git a/migration/migration.c b/migration/migration.c
index XXXXXXX..XXXXXXX 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -XXX,XX +XXX,XX @@ static void migrate_fd_cleanup(MigrationState *s)
         QEMUFile *tmp;
 
         trace_migrate_fd_cleanup();
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         if (s->migration_thread_running) {
             qemu_thread_join(&s->thread);
             s->migration_thread_running = false;
         }
-        qemu_mutex_lock_iothread();
+        bql_lock();
 
         multifd_save_cleanup();
         qemu_mutex_lock(&s->qemu_file_lock);
@@ -XXX,XX +XXX,XX @@ static int postcopy_start(MigrationState *ms, Error **errp)
     }
 
     trace_postcopy_start();
-    qemu_mutex_lock_iothread();
+    bql_lock();
     trace_postcopy_start_set_run();
 
     migration_downtime_start(ms);
@@ -XXX,XX +XXX,XX @@ static int postcopy_start(MigrationState *ms, Error **errp)
 
     migration_downtime_end(ms);
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     if (migrate_postcopy_ram()) {
         /*
@@ -XXX,XX +XXX,XX @@ fail:
             error_report_err(local_err);
         }
     }
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     return -1;
 }
 
@@ -XXX,XX +XXX,XX @@ static int migration_maybe_pause(MigrationState *s,
      * wait for the 'pause_sem' semaphore.
      */
     if (s->state != MIGRATION_STATUS_CANCELLING) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         migrate_set_state(&s->state, *current_active_state,
                           MIGRATION_STATUS_PRE_SWITCHOVER);
         qemu_sem_wait(&s->pause_sem);
         migrate_set_state(&s->state, MIGRATION_STATUS_PRE_SWITCHOVER,
                           new_state);
         *current_active_state = new_state;
-        qemu_mutex_lock_iothread();
+        bql_lock();
     }
 
     return s->state == new_state ? 0 : -EINVAL;
@@ -XXX,XX +XXX,XX @@ static int migration_completion_precopy(MigrationState *s,
 {
     int ret;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     migration_downtime_start(s);
 
     s->vm_old_state = runstate_get();
@@ -XXX,XX +XXX,XX @@ static int migration_completion_precopy(MigrationState *s,
     ret = qemu_savevm_state_complete_precopy(s->to_dst_file, false,
                                              s->block_inactive);
 out_unlock:
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     return ret;
 }
 
@@ -XXX,XX +XXX,XX @@ static void migration_completion_postcopy(MigrationState *s)
 {
     trace_migration_completion_postcopy_end();
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     qemu_savevm_state_complete_postcopy(s->to_dst_file);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     /*
      * Shutdown the postcopy fast path thread.  This is only needed when dest
@@ -XXX,XX +XXX,XX @@ static void migration_completion_failed(MigrationState *s,
          */
         Error *local_err = NULL;
 
-        qemu_mutex_lock_iothread();
+        bql_lock();
         bdrv_activate_all(&local_err);
         if (local_err) {
             error_report_err(local_err);
         } else {
             s->block_inactive = false;
         }
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 
     migrate_set_state(&s->state, current_active_state,
@@ -XXX,XX +XXX,XX @@ static void migration_iteration_finish(MigrationState *s)
     /* If we enabled cpu throttling for auto-converge, turn it off. */
     cpu_throttle_stop();
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     switch (s->state) {
     case MIGRATION_STATUS_COMPLETED:
         migration_calculate_complete(s);
@@ -XXX,XX +XXX,XX @@ static void migration_iteration_finish(MigrationState *s)
         break;
     }
     migrate_fd_cleanup_schedule(s);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 static void bg_migration_iteration_finish(MigrationState *s)
@@ -XXX,XX +XXX,XX @@ static void bg_migration_iteration_finish(MigrationState *s)
      */
     ram_write_tracking_stop();
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     switch (s->state) {
     case MIGRATION_STATUS_COMPLETED:
         migration_calculate_complete(s);
@@ -XXX,XX +XXX,XX @@ static void bg_migration_iteration_finish(MigrationState *s)
     }
 
     migrate_fd_cleanup_schedule(s);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 /*
@@ -XXX,XX +XXX,XX @@ static void *migration_thread(void *opaque)
     object_ref(OBJECT(s));
     update_iteration_initial_status(s);
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     qemu_savevm_state_header(s->to_dst_file);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     /*
      * If we opened the return path, we need to make sure dst has it
@@ -XXX,XX +XXX,XX @@ static void *migration_thread(void *opaque)
         qemu_savevm_send_colo_enable(s->to_dst_file);
     }
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     qemu_savevm_state_setup(s->to_dst_file);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     qemu_savevm_wait_unplug(s, MIGRATION_STATUS_SETUP,
                                MIGRATION_STATUS_ACTIVE);
@@ -XXX,XX +XXX,XX @@ static void *bg_migration_thread(void *opaque)
     ram_write_tracking_prepare();
 #endif
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     qemu_savevm_state_header(s->to_dst_file);
     qemu_savevm_state_setup(s->to_dst_file);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     qemu_savevm_wait_unplug(s, MIGRATION_STATUS_SETUP,
                                MIGRATION_STATUS_ACTIVE);
@@ -XXX,XX +XXX,XX @@ static void *bg_migration_thread(void *opaque)
     trace_migration_thread_setup_complete();
     migration_downtime_start(s);
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     s->vm_old_state = runstate_get();
 
@@ -XXX,XX +XXX,XX @@ static void *bg_migration_thread(void *opaque)
     s->vm_start_bh = qemu_bh_new(bg_migration_vm_start_bh, s);
     qemu_bh_schedule(s->vm_start_bh);
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     while (migration_is_active(s)) {
         MigIterateState iter_state = bg_migration_iteration_run(s);
@@ -XXX,XX +XXX,XX @@ fail:
     if (early_fail) {
         migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE,
                 MIGRATION_STATUS_FAILED);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 
     bg_migration_iteration_finish(s);
diff --git a/migration/ram.c b/migration/ram.c
index XXXXXXX..XXXXXXX 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -XXX,XX +XXX,XX @@ static int ram_save_setup(QEMUFile *f, void *opaque)
     migration_ops = g_malloc0(sizeof(MigrationOps));
     migration_ops->ram_save_target_page = ram_save_target_page_legacy;
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     ret = multifd_send_sync_main(f);
-    qemu_mutex_lock_iothread();
+    bql_lock();
     if (ret < 0) {
         return ret;
     }
@@ -XXX,XX +XXX,XX @@ static void ram_state_pending_exact(void *opaque, uint64_t *must_precopy,
     uint64_t remaining_size = rs->migration_dirty_pages * TARGET_PAGE_SIZE;
 
     if (!migration_in_postcopy() && remaining_size < s->threshold_size) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
         WITH_RCU_READ_LOCK_GUARD() {
             migration_bitmap_sync_precopy(rs, false);
         }
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         remaining_size = rs->migration_dirty_pages * TARGET_PAGE_SIZE;
     }
 
@@ -XXX,XX +XXX,XX @@ void colo_incoming_start_dirty_log(void)
 {
     RAMBlock *block = NULL;
     /* For memory_global_dirty_log_start below. */
-    qemu_mutex_lock_iothread();
+    bql_lock();
     qemu_mutex_lock_ramlist();
 
     memory_global_dirty_log_sync(false);
@@ -XXX,XX +XXX,XX @@ void colo_incoming_start_dirty_log(void)
     }
     ram_state->migration_dirty_pages = 0;
     qemu_mutex_unlock_ramlist();
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 /* It is need to hold the global lock to call this helper */
diff --git a/replay/replay-internal.c b/replay/replay-internal.c
index XXXXXXX..XXXXXXX 100644
--- a/replay/replay-internal.c
+++ b/replay/replay-internal.c
@@ -XXX,XX +XXX,XX @@ void replay_mutex_lock(void)
 {
     if (replay_mode != REPLAY_MODE_NONE) {
         unsigned long id;
-        g_assert(!qemu_mutex_iothread_locked());
+        g_assert(!bql_locked());
         g_assert(!replay_mutex_locked());
         qemu_mutex_lock(&lock);
         id = mutex_tail++;
diff --git a/semihosting/console.c b/semihosting/console.c
index XXXXXXX..XXXXXXX 100644
--- a/semihosting/console.c
+++ b/semihosting/console.c
@@ -XXX,XX +XXX,XX @@ static SemihostingConsole console;
 static int console_can_read(void *opaque)
 {
     SemihostingConsole *c = opaque;
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
     return (int)fifo8_num_free(&c->fifo);
 }
 
@@ -XXX,XX +XXX,XX @@ static void console_wake_up(gpointer data, gpointer user_data)
 static void console_read(void *opaque, const uint8_t *buf, int size)
 {
     SemihostingConsole *c = opaque;
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
     while (size-- && !fifo8_is_full(&c->fifo)) {
         fifo8_push(&c->fifo, *buf++);
     }
@@ -XXX,XX +XXX,XX @@ bool qemu_semihosting_console_ready(void)
 {
     SemihostingConsole *c = &console;
 
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
     return !fifo8_is_empty(&c->fifo);
 }
 
@@ -XXX,XX +XXX,XX @@ void qemu_semihosting_console_block_until_ready(CPUState *cs)
 {
     SemihostingConsole *c = &console;
 
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
 
     /* Block if the fifo is completely empty. */
     if (fifo8_is_empty(&c->fifo)) {
diff --git a/stubs/iothread-lock.c b/stubs/iothread-lock.c
index XXXXXXX..XXXXXXX 100644
--- a/stubs/iothread-lock.c
+++ b/stubs/iothread-lock.c
@@ -XXX,XX +XXX,XX @@
 #include "qemu/osdep.h"
 #include "qemu/main-loop.h"
 
-bool qemu_mutex_iothread_locked(void)
+bool bql_locked(void)
 {
     return false;
 }
 
-void qemu_mutex_lock_iothread_impl(const char *file, int line)
+void bql_lock_impl(const char *file, int line)
 {
 }
 
-void qemu_mutex_unlock_iothread(void)
+void bql_unlock(void)
 {
 }
diff --git a/system/cpu-throttle.c b/system/cpu-throttle.c
index XXXXXXX..XXXXXXX 100644
--- a/system/cpu-throttle.c
+++ b/system/cpu-throttle.c
@@ -XXX,XX +XXX,XX @@ static void cpu_throttle_thread(CPUState *cpu, run_on_cpu_data opaque)
             qemu_cond_timedwait_iothread(cpu->halt_cond,
                                          sleeptime_ns / SCALE_MS);
         } else {
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             g_usleep(sleeptime_ns / SCALE_US);
-            qemu_mutex_lock_iothread();
+            bql_lock();
         }
         sleeptime_ns = endtime_ns - qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
     }
diff --git a/system/cpus.c b/system/cpus.c
index XXXXXXX..XXXXXXX 100644
--- a/system/cpus.c
+++ b/system/cpus.c
@@ -XXX,XX +XXX,XX @@
 
 #endif /* CONFIG_LINUX */
 
-static QemuMutex qemu_global_mutex;
+/* The Big QEMU Lock (BQL) */
+static QemuMutex bql;
 
 /*
  * The chosen accelerator is supposed to register this.
@@ -XXX,XX +XXX,XX @@ void qemu_init_cpu_loop(void)
     qemu_init_sigbus();
     qemu_cond_init(&qemu_cpu_cond);
     qemu_cond_init(&qemu_pause_cond);
-    qemu_mutex_init(&qemu_global_mutex);
+    qemu_mutex_init(&bql);
 
     qemu_thread_get_self(&io_thread);
 }
 
 void run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data data)
 {
-    do_run_on_cpu(cpu, func, data, &qemu_global_mutex);
+    do_run_on_cpu(cpu, func, data, &bql);
 }
 
 static void qemu_cpu_stop(CPUState *cpu, bool exit)
@@ -XXX,XX +XXX,XX @@ void qemu_wait_io_event(CPUState *cpu)
             slept = true;
             qemu_plugin_vcpu_idle_cb(cpu);
         }
-        qemu_cond_wait(cpu->halt_cond, &qemu_global_mutex);
+        qemu_cond_wait(cpu->halt_cond, &bql);
     }
     if (slept) {
         qemu_plugin_vcpu_resume_cb(cpu);
@@ -XXX,XX +XXX,XX @@ bool qemu_in_vcpu_thread(void)
     return current_cpu && qemu_cpu_is_self(current_cpu);
 }
 
-QEMU_DEFINE_STATIC_CO_TLS(bool, iothread_locked)
+QEMU_DEFINE_STATIC_CO_TLS(bool, bql_locked)
 
-bool qemu_mutex_iothread_locked(void)
+bool bql_locked(void)
 {
-    return get_iothread_locked();
+    return get_bql_locked();
 }
 
 bool qemu_in_main_thread(void)
 {
-    return qemu_mutex_iothread_locked();
+    return bql_locked();
 }
 
 /*
  * The BQL is taken from so many places that it is worth profiling the
  * callers directly, instead of funneling them all through a single function.
  */
-void qemu_mutex_lock_iothread_impl(const char *file, int line)
+void bql_lock_impl(const char *file, int line)
 {
-    QemuMutexLockFunc bql_lock = qatomic_read(&qemu_bql_mutex_lock_func);
+    QemuMutexLockFunc bql_lock_fn = qatomic_read(&bql_mutex_lock_func);
 
-    g_assert(!qemu_mutex_iothread_locked());
-    bql_lock(&qemu_global_mutex, file, line);
-    set_iothread_locked(true);
+    g_assert(!bql_locked());
+    bql_lock_fn(&bql, file, line);
+    set_bql_locked(true);
 }
 
-void qemu_mutex_unlock_iothread(void)
+void bql_unlock(void)
 {
-    g_assert(qemu_mutex_iothread_locked());
-    set_iothread_locked(false);
-    qemu_mutex_unlock(&qemu_global_mutex);
+    g_assert(bql_locked());
+    set_bql_locked(false);
+    qemu_mutex_unlock(&bql);
 }
 
 void qemu_cond_wait_iothread(QemuCond *cond)
 {
-    qemu_cond_wait(cond, &qemu_global_mutex);
+    qemu_cond_wait(cond, &bql);
 }
 
 void qemu_cond_timedwait_iothread(QemuCond *cond, int ms)
 {
-    qemu_cond_timedwait(cond, &qemu_global_mutex, ms);
+    qemu_cond_timedwait(cond, &bql, ms);
 }
 
 /* signal CPU creation */
@@ -XXX,XX +XXX,XX @@ void pause_all_vcpus(void)
     replay_mutex_unlock();
 
     while (!all_vcpus_paused()) {
-        qemu_cond_wait(&qemu_pause_cond, &qemu_global_mutex);
+        qemu_cond_wait(&qemu_pause_cond, &bql);
         CPU_FOREACH(cpu) {
             qemu_cpu_kick(cpu);
         }
     }
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     replay_mutex_lock();
-    qemu_mutex_lock_iothread();
+    bql_lock();
 }
 
 void cpu_resume(CPUState *cpu)
@@ -XXX,XX +XXX,XX @@ void cpu_remove_sync(CPUState *cpu)
     cpu->stop = true;
     cpu->unplug = true;
     qemu_cpu_kick(cpu);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     qemu_thread_join(cpu->thread);
-    qemu_mutex_lock_iothread();
+    bql_lock();
 }
 
 void cpus_register_accel(const AccelOpsClass *ops)
@@ -XXX,XX +XXX,XX @@ void qemu_init_vcpu(CPUState *cpu)
     cpus_accel->create_vcpu_thread(cpu);
 
     while (!cpu->created) {
-        qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
+        qemu_cond_wait(&qemu_cpu_cond, &bql);
     }
 }
 
diff --git a/system/dirtylimit.c b/system/dirtylimit.c
index XXXXXXX..XXXXXXX 100644
--- a/system/dirtylimit.c
+++ b/system/dirtylimit.c
@@ -XXX,XX +XXX,XX @@ void vcpu_dirty_rate_stat_stop(void)
 {
     qatomic_set(&vcpu_dirty_rate_stat->running, 0);
     dirtylimit_state_unlock();
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     qemu_thread_join(&vcpu_dirty_rate_stat->thread);
-    qemu_mutex_lock_iothread();
+    bql_lock();
     dirtylimit_state_lock();
 }
 
diff --git a/system/memory.c b/system/memory.c
index XXXXXXX..XXXXXXX 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -XXX,XX +XXX,XX @@ void memory_region_transaction_commit(void)
     AddressSpace *as;
 
     assert(memory_region_transaction_depth);
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     --memory_region_transaction_depth;
     if (!memory_region_transaction_depth) {
diff --git a/system/physmem.c b/system/physmem.c
index XXXXXXX..XXXXXXX 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -XXX,XX +XXX,XX @@ bool prepare_mmio_access(MemoryRegion *mr)
 {
     bool release_lock = false;
 
-    if (!qemu_mutex_iothread_locked()) {
-        qemu_mutex_lock_iothread();
+    if (!bql_locked()) {
+        bql_lock();
         release_lock = true;
     }
     if (mr->flush_coalesced_mmio) {
@@ -XXX,XX +XXX,XX @@ static MemTxResult flatview_write_continue(FlatView *fv, hwaddr addr,
         }
 
         if (release_lock) {
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             release_lock = false;
         }
 
@@ -XXX,XX +XXX,XX @@ MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr,
         }
 
         if (release_lock) {
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             release_lock = false;
         }
 
diff --git a/system/runstate.c b/system/runstate.c
index XXXXXXX..XXXXXXX 100644
--- a/system/runstate.c
+++ b/system/runstate.c
@@ -XXX,XX +XXX,XX @@ void qemu_init_subsystems(void)
 
     qemu_init_cpu_list();
     qemu_init_cpu_loop();
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     atexit(qemu_run_exit_notifiers);
 
diff --git a/system/watchpoint.c b/system/watchpoint.c
index XXXXXXX..XXXXXXX 100644
--- a/system/watchpoint.c
+++ b/system/watchpoint.c
@@ -XXX,XX +XXX,XX @@ void cpu_check_watchpoint(CPUState *cpu, vaddr addr, vaddr len,
          * Now raise the debug interrupt so that it will
          * trigger after the current instruction.
          */
-        qemu_mutex_lock_iothread();
+        bql_lock();
         cpu_interrupt(cpu, CPU_INTERRUPT_DEBUG);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         return;
     }
 
diff --git a/target/arm/arm-powerctl.c b/target/arm/arm-powerctl.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/arm-powerctl.c
+++ b/target/arm/arm-powerctl.c
@@ -XXX,XX +XXX,XX @@ static void arm_set_cpu_on_async_work(CPUState *target_cpu_state,
     g_free(info);
 
     /* Finally set the power status */
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
     target_cpu->power_state = PSCI_ON;
 }
 
@@ -XXX,XX +XXX,XX @@ int arm_set_cpu_on(uint64_t cpuid, uint64_t entry, uint64_t context_id,
     ARMCPU *target_cpu;
     struct CpuOnInfo *info;
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     DPRINTF("cpu %" PRId64 " (EL %d, %s) @ 0x%" PRIx64 " with R0 = 0x%" PRIx64
             "\n", cpuid, target_el, target_aa64 ? "aarch64" : "aarch32", entry,
@@ -XXX,XX +XXX,XX @@ static void arm_set_cpu_on_and_reset_async_work(CPUState *target_cpu_state,
     target_cpu_state->halted = 0;
 
     /* Finally set the power status */
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
     target_cpu->power_state = PSCI_ON;
 }
 
@@ -XXX,XX +XXX,XX @@ int arm_set_cpu_on_and_reset(uint64_t cpuid)
     CPUState *target_cpu_state;
     ARMCPU *target_cpu;
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     /* Retrieve the cpu we are powering up */
     target_cpu_state = arm_get_cpu_by_id(cpuid);
@@ -XXX,XX +XXX,XX @@ static void arm_set_cpu_off_async_work(CPUState *target_cpu_state,
 {
     ARMCPU *target_cpu = ARM_CPU(target_cpu_state);
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
     target_cpu->power_state = PSCI_OFF;
     target_cpu_state->halted = 1;
     target_cpu_state->exception_index = EXCP_HLT;
@@ -XXX,XX +XXX,XX @@ int arm_set_cpu_off(uint64_t cpuid)
     CPUState *target_cpu_state;
     ARMCPU *target_cpu;
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     DPRINTF("cpu %" PRId64 "\n", cpuid);
 
@@ -XXX,XX +XXX,XX @@ int arm_reset_cpu(uint64_t cpuid)
     CPUState *target_cpu_state;
     ARMCPU *target_cpu;
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     DPRINTF("cpu %" PRId64 "\n", cpuid);
 
diff --git a/target/arm/helper.c b/target/arm/helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -XXX,XX +XXX,XX @@ static void do_hcr_write(CPUARMState *env, uint64_t value, uint64_t valid_mask)
      * VFIQ are masked unless running at EL0 or EL1, and HCR
      * can only be written at EL2.
      */
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
     arm_cpu_update_virq(cpu);
     arm_cpu_update_vfiq(cpu);
     arm_cpu_update_vserr(cpu);
@@ -XXX,XX +XXX,XX @@ void arm_cpu_do_interrupt(CPUState *cs)
      * BQL needs to be held for any modification of
      * cs->interrupt_request.
      */
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
 
     arm_call_pre_el_change_hook(cpu);
 
diff --git a/target/arm/hvf/hvf.c b/target/arm/hvf/hvf.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/hvf/hvf.c
+++ b/target/arm/hvf/hvf.c
@@ -XXX,XX +XXX,XX @@ static void hvf_wait_for_ipi(CPUState *cpu, struct timespec *ts)
      * sleeping.
      */
     qatomic_set_mb(&cpu->thread_kicked, false);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     pselect(0, 0, 0, 0, ts, &cpu->accel->unblock_ipi_mask);
-    qemu_mutex_lock_iothread();
+    bql_lock();
 }
 
 static void hvf_wfi(CPUState *cpu)
@@ -XXX,XX +XXX,XX @@ int hvf_vcpu_exec(CPUState *cpu)
 
     flush_cpu_state(cpu);
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     assert_hvf_ok(hv_vcpu_run(cpu->accel->fd));
 
     /* handle VMEXIT */
@@ -XXX,XX +XXX,XX @@ int hvf_vcpu_exec(CPUState *cpu)
     uint32_t ec = syn_get_ec(syndrome);
 
     ret = 0;
-    qemu_mutex_lock_iothread();
+    bql_lock();
     switch (exit_reason) {
     case HV_EXIT_REASON_EXCEPTION:
         /* This is the main one, handle below. */
diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -XXX,XX +XXX,XX @@ MemTxAttrs kvm_arch_post_run(CPUState *cs, struct kvm_run *run)
     if (run->s.regs.device_irq_level != cpu->device_irq_level) {
         switched_level = cpu->device_irq_level ^ run->s.regs.device_irq_level;
 
-        qemu_mutex_lock_iothread();
+        bql_lock();
 
         if (switched_level & KVM_ARM_DEV_EL1_VTIMER) {
             qemu_set_irq(cpu->gt_timer_outputs[GTIMER_VIRT],
@@ -XXX,XX +XXX,XX @@ MemTxAttrs kvm_arch_post_run(CPUState *cs, struct kvm_run *run)
 
         /* We also mark unknown levels as processed to not waste cycles */
         cpu->device_irq_level = run->s.regs.device_irq_level;
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 
     return MEMTXATTRS_UNSPECIFIED;
@@ -XXX,XX +XXX,XX @@ static bool kvm_arm_handle_debug(ARMCPU *cpu,
     env->exception.syndrome = debug_exit->hsr;
     env->exception.vaddress = debug_exit->far;
     env->exception.target_el = 1;
-    qemu_mutex_lock_iothread();
+    bql_lock();
     arm_cpu_do_interrupt(cs);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     return false;
 }
diff --git a/target/arm/ptw.c b/target/arm/ptw.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/ptw.c
+++ b/target/arm/ptw.c
@@ -XXX,XX +XXX,XX @@ static uint64_t arm_casq_ptw(CPUARMState *env, uint64_t old_val,
 #if !TCG_OVERSIZED_GUEST
 # error "Unexpected configuration"
 #endif
-    bool locked = qemu_mutex_iothread_locked();
+    bool locked = bql_locked();
     if (!locked) {
-       qemu_mutex_lock_iothread();
+        bql_lock();
     }
     if (ptw->out_be) {
         cur_val = ldq_be_p(host);
@@ -XXX,XX +XXX,XX @@ static uint64_t arm_casq_ptw(CPUARMState *env, uint64_t old_val,
         }
     }
     if (!locked) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 #endif
 
diff --git a/target/arm/tcg/helper-a64.c b/target/arm/tcg/helper-a64.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/tcg/helper-a64.c
+++ b/target/arm/tcg/helper-a64.c
@@ -XXX,XX +XXX,XX @@ void HELPER(exception_return)(CPUARMState *env, uint64_t new_pc)
         goto illegal_return;
     }
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     arm_call_pre_el_change_hook(env_archcpu(env));
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     if (!return_to_aa64) {
         env->aarch64 = false;
@@ -XXX,XX +XXX,XX @@ void HELPER(exception_return)(CPUARMState *env, uint64_t new_pc)
      */
     aarch64_sve_change_el(env, cur_el, new_el, return_to_aa64);
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     arm_call_el_change_hook(env_archcpu(env));
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     return;
 
diff --git a/target/arm/tcg/m_helper.c b/target/arm/tcg/m_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/tcg/m_helper.c
+++ b/target/arm/tcg/m_helper.c
@@ -XXX,XX +XXX,XX @@ void HELPER(v7m_preserve_fp_state)(CPUARMState *env)
     bool ts = is_secure && (env->v7m.fpccr[M_REG_S] & R_V7M_FPCCR_TS_MASK);
     bool take_exception;
 
-    /* Take the iothread lock as we are going to touch the NVIC */
-    qemu_mutex_lock_iothread();
+    /* Take the BQL as we are going to touch the NVIC */
+    bql_lock();
 
     /* Check the background context had access to the FPU */
     if (!v7m_cpacr_pass(env, is_secure, is_priv)) {
@@ -XXX,XX +XXX,XX @@ void HELPER(v7m_preserve_fp_state)(CPUARMState *env)
     take_exception = !stacked_ok &&
         armv7m_nvic_can_take_pending_exception(env->nvic);
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     if (take_exception) {
         raise_exception_ra(env, EXCP_LAZYFP, 0, 1, GETPC());
diff --git a/target/arm/tcg/op_helper.c b/target/arm/tcg/op_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/tcg/op_helper.c
+++ b/target/arm/tcg/op_helper.c
@@ -XXX,XX +XXX,XX @@ void HELPER(cpsr_write_eret)(CPUARMState *env, uint32_t val)
 {
     uint32_t mask;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     arm_call_pre_el_change_hook(env_archcpu(env));
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     mask = aarch32_cpsr_valid_mask(env->features, &env_archcpu(env)->isar);
     cpsr_write(env, val, mask, CPSRWriteExceptionReturn);
@@ -XXX,XX +XXX,XX @@ void HELPER(cpsr_write_eret)(CPUARMState *env, uint32_t val)
     env->regs[15] &= (env->thumb ? ~1 : ~3);
     arm_rebuild_hflags(env);
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     arm_call_el_change_hook(env_archcpu(env));
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 /* Access to user mode registers from privileged modes.  */
@@ -XXX,XX +XXX,XX @@ void HELPER(set_cp_reg)(CPUARMState *env, const void *rip, uint32_t value)
     const ARMCPRegInfo *ri = rip;
 
     if (ri->type & ARM_CP_IO) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
         ri->writefn(env, ri, value);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     } else {
         ri->writefn(env, ri, value);
     }
@@ -XXX,XX +XXX,XX @@ uint32_t HELPER(get_cp_reg)(CPUARMState *env, const void *rip)
     uint32_t res;
 
     if (ri->type & ARM_CP_IO) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
         res = ri->readfn(env, ri);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     } else {
         res = ri->readfn(env, ri);
     }
@@ -XXX,XX +XXX,XX @@ void HELPER(set_cp_reg64)(CPUARMState *env, const void *rip, uint64_t value)
     const ARMCPRegInfo *ri = rip;
 
     if (ri->type & ARM_CP_IO) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
         ri->writefn(env, ri, value);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     } else {
         ri->writefn(env, ri, value);
     }
@@ -XXX,XX +XXX,XX @@ uint64_t HELPER(get_cp_reg64)(CPUARMState *env, const void *rip)
     uint64_t res;
 
     if (ri->type & ARM_CP_IO) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
         res = ri->readfn(env, ri);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     } else {
         res = ri->readfn(env, ri);
     }
diff --git a/target/arm/tcg/psci.c b/target/arm/tcg/psci.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/tcg/psci.c
+++ b/target/arm/tcg/psci.c
@@ -XXX,XX +XXX,XX @@ void arm_handle_psci_call(ARMCPU *cpu)
             }
             target_cpu = ARM_CPU(target_cpu_state);
 
-            g_assert(qemu_mutex_iothread_locked());
+            g_assert(bql_locked());
             ret = target_cpu->power_state;
             break;
         default:
diff --git a/target/hppa/int_helper.c b/target/hppa/int_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/hppa/int_helper.c
+++ b/target/hppa/int_helper.c
@@ -XXX,XX +XXX,XX @@ void hppa_cpu_alarm_timer(void *opaque)
 void HELPER(write_eirr)(CPUHPPAState *env, target_ulong val)
 {
     env->cr[CR_EIRR] &= ~val;
-    qemu_mutex_lock_iothread();
+    bql_lock();
     eval_interrupt(env_archcpu(env));
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(write_eiem)(CPUHPPAState *env, target_ulong val)
 {
     env->cr[CR_EIEM] = val;
-    qemu_mutex_lock_iothread();
+    bql_lock();
     eval_interrupt(env_archcpu(env));
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void hppa_cpu_do_interrupt(CPUState *cs)
diff --git a/target/i386/hvf/hvf.c b/target/i386/hvf/hvf.c
index XXXXXXX..XXXXXXX 100644
--- a/target/i386/hvf/hvf.c
+++ b/target/i386/hvf/hvf.c
@@ -XXX,XX +XXX,XX @@ int hvf_vcpu_exec(CPUState *cpu)
         }
         vmx_update_tpr(cpu);
 
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         if (!cpu_is_bsp(X86_CPU(cpu)) && cpu->halted) {
-            qemu_mutex_lock_iothread();
+            bql_lock();
             return EXCP_HLT;
         }
 
@@ -XXX,XX +XXX,XX @@ int hvf_vcpu_exec(CPUState *cpu)
         rip = rreg(cpu->accel->fd, HV_X86_RIP);
         env->eflags = rreg(cpu->accel->fd, HV_X86_RFLAGS);
 
-        qemu_mutex_lock_iothread();
+        bql_lock();
 
         update_apic_tpr(cpu);
         current_cpu = cpu;
diff --git a/target/i386/kvm/hyperv.c b/target/i386/kvm/hyperv.c
index XXXXXXX..XXXXXXX 100644
--- a/target/i386/kvm/hyperv.c
+++ b/target/i386/kvm/hyperv.c
@@ -XXX,XX +XXX,XX @@ void hyperv_x86_synic_update(X86CPU *cpu)
 
 static void async_synic_update(CPUState *cs, run_on_cpu_data data)
 {
-    qemu_mutex_lock_iothread();
+    bql_lock();
     hyperv_x86_synic_update(X86_CPU(cs));
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 int kvm_hv_handle_exit(X86CPU *cpu, struct kvm_hyperv_exit *exit)
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index XXXXXXX..XXXXXXX 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -XXX,XX +XXX,XX @@ void kvm_arch_pre_run(CPUState *cpu, struct kvm_run *run)
     /* Inject NMI */
     if (cpu->interrupt_request & (CPU_INTERRUPT_NMI | CPU_INTERRUPT_SMI)) {
         if (cpu->interrupt_request & CPU_INTERRUPT_NMI) {
-            qemu_mutex_lock_iothread();
+            bql_lock();
             cpu->interrupt_request &= ~CPU_INTERRUPT_NMI;
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             DPRINTF("injected NMI\n");
             ret = kvm_vcpu_ioctl(cpu, KVM_NMI);
             if (ret < 0) {
@@ -XXX,XX +XXX,XX @@ void kvm_arch_pre_run(CPUState *cpu, struct kvm_run *run)
             }
         }
         if (cpu->interrupt_request & CPU_INTERRUPT_SMI) {
-            qemu_mutex_lock_iothread();
+            bql_lock();
             cpu->interrupt_request &= ~CPU_INTERRUPT_SMI;
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             DPRINTF("injected SMI\n");
             ret = kvm_vcpu_ioctl(cpu, KVM_SMI);
             if (ret < 0) {
@@ -XXX,XX +XXX,XX @@ void kvm_arch_pre_run(CPUState *cpu, struct kvm_run *run)
     }
 
     if (!kvm_pic_in_kernel()) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
     }
 
     /* Force the VCPU out of its inner loop to process any INIT requests
@@ -XXX,XX +XXX,XX @@ void kvm_arch_pre_run(CPUState *cpu, struct kvm_run *run)
         DPRINTF("setting tpr\n");
         run->cr8 = cpu_get_apic_tpr(x86_cpu->apic_state);
 
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 }
 
@@ -XXX,XX +XXX,XX @@ MemTxAttrs kvm_arch_post_run(CPUState *cpu, struct kvm_run *run)
     /* We need to protect the apic state against concurrent accesses from
      * different threads in case the userspace irqchip is used. */
     if (!kvm_irqchip_in_kernel()) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
     }
     cpu_set_apic_tpr(x86_cpu->apic_state, run->cr8);
     cpu_set_apic_base(x86_cpu->apic_state, run->apic_base);
     if (!kvm_irqchip_in_kernel()) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
     return cpu_get_mem_attrs(env);
 }
@@ -XXX,XX +XXX,XX @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
     switch (run->exit_reason) {
     case KVM_EXIT_HLT:
         DPRINTF("handle_hlt\n");
-        qemu_mutex_lock_iothread();
+        bql_lock();
         ret = kvm_handle_halt(cpu);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         break;
     case KVM_EXIT_SET_TPR:
         ret = 0;
         break;
     case KVM_EXIT_TPR_ACCESS:
-        qemu_mutex_lock_iothread();
+        bql_lock();
         ret = kvm_handle_tpr_access(cpu);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         break;
     case KVM_EXIT_FAIL_ENTRY:
         code = run->fail_entry.hardware_entry_failure_reason;
@@ -XXX,XX +XXX,XX @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
         break;
     case KVM_EXIT_DEBUG:
         DPRINTF("kvm_exit_debug\n");
-        qemu_mutex_lock_iothread();
+        bql_lock();
         ret = kvm_handle_debug(cpu, &run->debug.arch);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         break;
     case KVM_EXIT_HYPERV:
         ret = kvm_hv_handle_exit(cpu, &run->hyperv);
diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c
index XXXXXXX..XXXXXXX 100644
--- a/target/i386/kvm/xen-emu.c
+++ b/target/i386/kvm/xen-emu.c
@@ -XXX,XX +XXX,XX @@ void kvm_xen_maybe_deassert_callback(CPUState *cs)
 
     /* If the evtchn_upcall_pending flag is cleared, turn the GSI off. */
     if (!vi->evtchn_upcall_pending) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
         /*
          * Check again now we have the lock, because it may have been
          * asserted in the interim. And we don't want to take the lock
@@ -XXX,XX +XXX,XX @@ void kvm_xen_maybe_deassert_callback(CPUState *cs)
             X86_CPU(cs)->env.xen_callback_asserted = false;
             xen_evtchn_set_callback_level(0);
         }
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 }
 
@@ -XXX,XX +XXX,XX @@ static bool handle_set_param(struct kvm_xen_exit *exit, X86CPU *cpu,
 
     switch (hp.index) {
     case HVM_PARAM_CALLBACK_IRQ:
-        qemu_mutex_lock_iothread();
+        bql_lock();
         err = xen_evtchn_set_callback_param(hp.value);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         xen_set_long_mode(exit->u.hcall.longmode);
         break;
     default:
@@ -XXX,XX +XXX,XX @@ int kvm_xen_soft_reset(void)
     CPUState *cpu;
     int err;
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     trace_kvm_xen_soft_reset();
 
@@ -XXX,XX +XXX,XX @@ static int schedop_shutdown(CPUState *cs, uint64_t arg)
         break;
 
     case SHUTDOWN_soft_reset:
-        qemu_mutex_lock_iothread();
+        bql_lock();
         ret = kvm_xen_soft_reset();
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         break;
 
     default:
diff --git a/target/i386/nvmm/nvmm-accel-ops.c b/target/i386/nvmm/nvmm-accel-ops.c
index XXXXXXX..XXXXXXX 100644
--- a/target/i386/nvmm/nvmm-accel-ops.c
+++ b/target/i386/nvmm/nvmm-accel-ops.c
@@ -XXX,XX +XXX,XX @@ static void *qemu_nvmm_cpu_thread_fn(void *arg)
 
     rcu_register_thread();
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     qemu_thread_get_self(cpu->thread);
     cpu->thread_id = qemu_get_thread_id();
     current_cpu = cpu;
@@ -XXX,XX +XXX,XX @@ static void *qemu_nvmm_cpu_thread_fn(void *arg)
 
     nvmm_destroy_vcpu(cpu);
     cpu_thread_signal_destroyed(cpu);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     rcu_unregister_thread();
     return NULL;
 }
diff --git a/target/i386/nvmm/nvmm-all.c b/target/i386/nvmm/nvmm-all.c
index XXXXXXX..XXXXXXX 100644
--- a/target/i386/nvmm/nvmm-all.c
+++ b/target/i386/nvmm/nvmm-all.c
@@ -XXX,XX +XXX,XX @@ nvmm_vcpu_pre_run(CPUState *cpu)
     uint8_t tpr;
     int ret;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     tpr = cpu_get_apic_tpr(x86_cpu->apic_state);
     if (tpr != qcpu->tpr) {
@@ -XXX,XX +XXX,XX @@ nvmm_vcpu_pre_run(CPUState *cpu)
         }
     }
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 /*
@@ -XXX,XX +XXX,XX @@ nvmm_vcpu_post_run(CPUState *cpu, struct nvmm_vcpu_exit *exit)
     tpr = exit->exitstate.cr8;
     if (qcpu->tpr != tpr) {
         qcpu->tpr = tpr;
-        qemu_mutex_lock_iothread();
+        bql_lock();
         cpu_set_apic_tpr(x86_cpu->apic_state, qcpu->tpr);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 }
 
@@ -XXX,XX +XXX,XX @@ nvmm_handle_halted(struct nvmm_machine *mach, CPUState *cpu,
     CPUX86State *env = cpu_env(cpu);
     int ret = 0;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     if (!((cpu->interrupt_request & CPU_INTERRUPT_HARD) &&
           (env->eflags & IF_MASK)) &&
@@ -XXX,XX +XXX,XX @@ nvmm_handle_halted(struct nvmm_machine *mach, CPUState *cpu,
         ret = 1;
     }
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     return ret;
 }
@@ -XXX,XX +XXX,XX @@ nvmm_vcpu_loop(CPUState *cpu)
         return 0;
     }
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     cpu_exec_start(cpu);
 
     /*
@@ -XXX,XX +XXX,XX @@ nvmm_vcpu_loop(CPUState *cpu)
             error_report("NVMM: Unexpected VM exit code 0x%lx [hw=0x%lx]",
                 exit->reason, exit->u.inv.hwcode);
             nvmm_get_registers(cpu);
-            qemu_mutex_lock_iothread();
+            bql_lock();
             qemu_system_guest_panicked(cpu_get_crash_info(cpu));
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             ret = -1;
             break;
         }
     } while (ret == 0);
 
     cpu_exec_end(cpu);
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     qatomic_set(&cpu->exit_request, false);
 
diff --git a/target/i386/tcg/sysemu/fpu_helper.c b/target/i386/tcg/sysemu/fpu_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/i386/tcg/sysemu/fpu_helper.c
+++ b/target/i386/tcg/sysemu/fpu_helper.c
@@ -XXX,XX +XXX,XX @@ void x86_register_ferr_irq(qemu_irq irq)
 void fpu_check_raise_ferr_irq(CPUX86State *env)
 {
     if (ferr_irq && !(env->hflags2 & HF2_IGNNE_MASK)) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
         qemu_irq_raise(ferr_irq);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         return;
     }
 }
@@ -XXX,XX +XXX,XX @@ void cpu_set_ignne(void)
 {
     CPUX86State *env = &X86_CPU(first_cpu)->env;
 
-    assert(qemu_mutex_iothread_locked());
+    assert(bql_locked());
 
     env->hflags2 |= HF2_IGNNE_MASK;
     /*
diff --git a/target/i386/tcg/sysemu/misc_helper.c b/target/i386/tcg/sysemu/misc_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/i386/tcg/sysemu/misc_helper.c
+++ b/target/i386/tcg/sysemu/misc_helper.c
@@ -XXX,XX +XXX,XX @@ void helper_write_crN(CPUX86State *env, int reg, target_ulong t0)
         break;
     case 8:
         if (!(env->hflags2 & HF2_VINTR_MASK)) {
-            qemu_mutex_lock_iothread();
+            bql_lock();
             cpu_set_apic_tpr(env_archcpu(env)->apic_state, t0);
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
         }
         env->int_ctl = (env->int_ctl & ~V_TPR_MASK) | (t0 & V_TPR_MASK);
 
diff --git a/target/i386/whpx/whpx-accel-ops.c b/target/i386/whpx/whpx-accel-ops.c
index XXXXXXX..XXXXXXX 100644
--- a/target/i386/whpx/whpx-accel-ops.c
+++ b/target/i386/whpx/whpx-accel-ops.c
@@ -XXX,XX +XXX,XX @@ static void *whpx_cpu_thread_fn(void *arg)
 
     rcu_register_thread();
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     qemu_thread_get_self(cpu->thread);
     cpu->thread_id = qemu_get_thread_id();
     current_cpu = cpu;
@@ -XXX,XX +XXX,XX @@ static void *whpx_cpu_thread_fn(void *arg)
 
     whpx_destroy_vcpu(cpu);
     cpu_thread_signal_destroyed(cpu);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     rcu_unregister_thread();
     return NULL;
 }
diff --git a/target/i386/whpx/whpx-all.c b/target/i386/whpx/whpx-all.c
index XXXXXXX..XXXXXXX 100644
--- a/target/i386/whpx/whpx-all.c
+++ b/target/i386/whpx/whpx-all.c
@@ -XXX,XX +XXX,XX @@ static int whpx_first_vcpu_starting(CPUState *cpu)
     struct whpx_state *whpx = &whpx_global;
     HRESULT hr;
 
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
 
     if (!QTAILQ_EMPTY(&cpu->breakpoints) ||
             (whpx->breakpoints.breakpoints &&
@@ -XXX,XX +XXX,XX @@ static int whpx_handle_halt(CPUState *cpu)
     CPUX86State *env = cpu_env(cpu);
     int ret = 0;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     if (!((cpu->interrupt_request & CPU_INTERRUPT_HARD) &&
           (env->eflags & IF_MASK)) &&
         !(cpu->interrupt_request & CPU_INTERRUPT_NMI)) {
@@ -XXX,XX +XXX,XX @@ static int whpx_handle_halt(CPUState *cpu)
         cpu->halted = true;
         ret = 1;
     }
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     return ret;
 }
@@ -XXX,XX +XXX,XX @@ static void whpx_vcpu_pre_run(CPUState *cpu)
     memset(&new_int, 0, sizeof(new_int));
     memset(reg_values, 0, sizeof(reg_values));
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     /* Inject NMI */
     if (!vcpu->interruption_pending &&
@@ -XXX,XX +XXX,XX @@ static void whpx_vcpu_pre_run(CPUState *cpu)
         reg_count += 1;
     }
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     vcpu->ready_for_pic_interrupt = false;
 
     if (reg_count) {
@@ -XXX,XX +XXX,XX @@ static void whpx_vcpu_post_run(CPUState *cpu)
     uint64_t tpr = vcpu->exit_ctx.VpContext.Cr8;
     if (vcpu->tpr != tpr) {
         vcpu->tpr = tpr;
-        qemu_mutex_lock_iothread();
+        bql_lock();
         cpu_set_apic_tpr(x86_cpu->apic_state, whpx_cr8_to_apic_tpr(vcpu->tpr));
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 
     vcpu->interruption_pending =
@@ -XXX,XX +XXX,XX @@ static int whpx_vcpu_run(CPUState *cpu)
     WhpxStepMode exclusive_step_mode = WHPX_STEP_NONE;
     int ret;
 
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
 
     if (whpx->running_cpus++ == 0) {
         /* Insert breakpoints into memory, update exception exit bitmap. */
@@ -XXX,XX +XXX,XX @@ static int whpx_vcpu_run(CPUState *cpu)
         }
     }
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     if (exclusive_step_mode != WHPX_STEP_NONE) {
         start_exclusive();
@@ -XXX,XX +XXX,XX @@ static int whpx_vcpu_run(CPUState *cpu)
             error_report("WHPX: Unexpected VP exit code %d",
                          vcpu->exit_ctx.ExitReason);
             whpx_get_registers(cpu);
-            qemu_mutex_lock_iothread();
+            bql_lock();
             qemu_system_guest_panicked(cpu_get_crash_info(cpu));
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             break;
         }
 
@@ -XXX,XX +XXX,XX @@ static int whpx_vcpu_run(CPUState *cpu)
         cpu_exec_end(cpu);
     }
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     current_cpu = cpu;
 
     if (--whpx->running_cpus == 0) {
diff --git a/target/loongarch/tcg/csr_helper.c b/target/loongarch/tcg/csr_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/loongarch/tcg/csr_helper.c
+++ b/target/loongarch/tcg/csr_helper.c
@@ -XXX,XX +XXX,XX @@ target_ulong helper_csrwr_ticlr(CPULoongArchState *env, target_ulong val)
     int64_t old_v = 0;
 
     if (val & 0x1) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
         loongarch_cpu_set_irq(cpu, IRQ_TIMER, 0);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
     return old_v;
 }
diff --git a/target/mips/kvm.c b/target/mips/kvm.c
index XXXXXXX..XXXXXXX 100644
--- a/target/mips/kvm.c
+++ b/target/mips/kvm.c
@@ -XXX,XX +XXX,XX @@ void kvm_arch_pre_run(CPUState *cs, struct kvm_run *run)
     int r;
     struct kvm_mips_interrupt intr;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     if ((cs->interrupt_request & CPU_INTERRUPT_HARD) &&
             cpu_mips_io_interrupts_pending(cpu)) {
@@ -XXX,XX +XXX,XX @@ void kvm_arch_pre_run(CPUState *cs, struct kvm_run *run)
         }
     }
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 MemTxAttrs kvm_arch_post_run(CPUState *cs, struct kvm_run *run)
diff --git a/target/mips/tcg/sysemu/cp0_helper.c b/target/mips/tcg/sysemu/cp0_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/mips/tcg/sysemu/cp0_helper.c
+++ b/target/mips/tcg/sysemu/cp0_helper.c
@@ -XXX,XX +XXX,XX @@ static inline void mips_vpe_wake(MIPSCPU *c)
      * because there might be other conditions that state that c should
      * be sleeping.
      */
-    qemu_mutex_lock_iothread();
+    bql_lock();
     cpu_interrupt(CPU(c), CPU_INTERRUPT_WAKE);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 static inline void mips_vpe_sleep(MIPSCPU *cpu)
diff --git a/target/openrisc/sys_helper.c b/target/openrisc/sys_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/openrisc/sys_helper.c
+++ b/target/openrisc/sys_helper.c
@@ -XXX,XX +XXX,XX @@ void HELPER(mtspr)(CPUOpenRISCState *env, target_ulong spr, target_ulong rb)
         break;
     case TO_SPR(9, 0):  /* PICMR */
         env->picmr = rb;
-        qemu_mutex_lock_iothread();
+        bql_lock();
         if (env->picsr & env->picmr) {
             cpu_interrupt(cs, CPU_INTERRUPT_HARD);
         } else {
             cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
         }
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         break;
     case TO_SPR(9, 2):  /* PICSR */
         env->picsr &= ~rb;
         break;
     case TO_SPR(10, 0): /* TTMR */
         {
-            qemu_mutex_lock_iothread();
+            bql_lock();
             if ((env->ttmr & TTMR_M) ^ (rb & TTMR_M)) {
                 switch (rb & TTMR_M) {
                 case TIMER_NONE:
@@ -XXX,XX +XXX,XX @@ void HELPER(mtspr)(CPUOpenRISCState *env, target_ulong spr, target_ulong rb)
                 cs->interrupt_request &= ~CPU_INTERRUPT_TIMER;
             }
             cpu_openrisc_timer_update(cpu);
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
         }
         break;
 
     case TO_SPR(10, 1): /* TTCR */
-        qemu_mutex_lock_iothread();
+        bql_lock();
         cpu_openrisc_count_set(cpu, rb);
         cpu_openrisc_timer_update(cpu);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         break;
     }
 #endif
@@ -XXX,XX +XXX,XX @@ target_ulong HELPER(mfspr)(CPUOpenRISCState *env, target_ulong rd,
         return env->ttmr;
 
     case TO_SPR(10, 1): /* TTCR */
-        qemu_mutex_lock_iothread();
+        bql_lock();
         cpu_openrisc_count_update(cpu);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         return cpu_openrisc_count_get(cpu);
     }
 #endif
diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/ppc/excp_helper.c
+++ b/target/ppc/excp_helper.c
@@ -XXX,XX +XXX,XX @@ void helper_msgsnd(target_ulong rb)
         return;
     }
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     CPU_FOREACH(cs) {
         PowerPCCPU *cpu = POWERPC_CPU(cs);
         CPUPPCState *cenv = &cpu->env;
@@ -XXX,XX +XXX,XX @@ void helper_msgsnd(target_ulong rb)
             ppc_set_irq(cpu, irq, 1);
         }
     }
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 /* Server Processor Control */
@@ -XXX,XX +XXX,XX @@ static void book3s_msgsnd_common(int pir, int irq)
 {
     CPUState *cs;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     CPU_FOREACH(cs) {
         PowerPCCPU *cpu = POWERPC_CPU(cs);
         CPUPPCState *cenv = &cpu->env;
@@ -XXX,XX +XXX,XX @@ static void book3s_msgsnd_common(int pir, int irq)
             ppc_set_irq(cpu, irq, 1);
         }
     }
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void helper_book3s_msgsnd(target_ulong rb)
@@ -XXX,XX +XXX,XX @@ void helper_book3s_msgsndp(CPUPPCState *env, target_ulong rb)
     }
 
     /* Does iothread need to be locked for walking CPU list? */
-    qemu_mutex_lock_iothread();
+    bql_lock();
     THREAD_SIBLING_FOREACH(cs, ccs) {
         PowerPCCPU *ccpu = POWERPC_CPU(ccs);
         uint32_t thread_id = ppc_cpu_tir(ccpu);
 
         if (ttir == thread_id) {
             ppc_set_irq(ccpu, PPC_INTERRUPT_DOORBELL, 1);
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             return;
         }
     }
diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index XXXXXXX..XXXXXXX 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -XXX,XX +XXX,XX @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
     CPUPPCState *env = &cpu->env;
     int ret;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     switch (run->exit_reason) {
     case KVM_EXIT_DCR:
@@ -XXX,XX +XXX,XX @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
         break;
     }
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     return ret;
 }
 
diff --git a/target/ppc/misc_helper.c b/target/ppc/misc_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/ppc/misc_helper.c
+++ b/target/ppc/misc_helper.c
@@ -XXX,XX +XXX,XX @@ target_ulong helper_load_dpdes(CPUPPCState *env)
         return dpdes;
     }
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     THREAD_SIBLING_FOREACH(cs, ccs) {
         PowerPCCPU *ccpu = POWERPC_CPU(ccs);
         CPUPPCState *cenv = &ccpu->env;
@@ -XXX,XX +XXX,XX @@ target_ulong helper_load_dpdes(CPUPPCState *env)
             dpdes |= (0x1 << thread_id);
         }
     }
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     return dpdes;
 }
@@ -XXX,XX +XXX,XX @@ void helper_store_dpdes(CPUPPCState *env, target_ulong val)
     }
 
     /* Does iothread need to be locked for walking CPU list? */
-    qemu_mutex_lock_iothread();
+    bql_lock();
     THREAD_SIBLING_FOREACH(cs, ccs) {
         PowerPCCPU *ccpu = POWERPC_CPU(ccs);
         uint32_t thread_id = ppc_cpu_tir(ccpu);
 
         ppc_set_irq(cpu, PPC_INTERRUPT_DOORBELL, val & (0x1 << thread_id));
     }
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 #endif /* defined(TARGET_PPC64) */
 
diff --git a/target/ppc/timebase_helper.c b/target/ppc/timebase_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/ppc/timebase_helper.c
+++ b/target/ppc/timebase_helper.c
@@ -XXX,XX +XXX,XX @@ target_ulong helper_load_dcr(CPUPPCState *env, target_ulong dcrn)
     } else {
         int ret;
 
-        qemu_mutex_lock_iothread();
+        bql_lock();
         ret = ppc_dcr_read(env->dcr_env, (uint32_t)dcrn, &val);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         if (unlikely(ret != 0)) {
             qemu_log_mask(LOG_GUEST_ERROR, "DCR read error %d %03x\n",
                           (uint32_t)dcrn, (uint32_t)dcrn);
@@ -XXX,XX +XXX,XX @@ void helper_store_dcr(CPUPPCState *env, target_ulong dcrn, target_ulong val)
                                POWERPC_EXCP_INVAL_INVAL, GETPC());
     } else {
         int ret;
-        qemu_mutex_lock_iothread();
+        bql_lock();
         ret = ppc_dcr_write(env->dcr_env, (uint32_t)dcrn, (uint32_t)val);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         if (unlikely(ret != 0)) {
             qemu_log_mask(LOG_GUEST_ERROR, "DCR write error %d %03x\n",
                           (uint32_t)dcrn, (uint32_t)dcrn);
diff --git a/target/s390x/kvm/kvm.c b/target/s390x/kvm/kvm.c
index XXXXXXX..XXXXXXX 100644
--- a/target/s390x/kvm/kvm.c
+++ b/target/s390x/kvm/kvm.c
@@ -XXX,XX +XXX,XX @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
     S390CPU *cpu = S390_CPU(cs);
     int ret = 0;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     kvm_cpu_synchronize_state(cs);
 
@@ -XXX,XX +XXX,XX @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
             fprintf(stderr, "Unknown KVM exit: %d\n", run->exit_reason);
             break;
     }
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     if (ret == 0) {
         ret = EXCP_INTERRUPT;
diff --git a/target/s390x/tcg/misc_helper.c b/target/s390x/tcg/misc_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/s390x/tcg/misc_helper.c
+++ b/target/s390x/tcg/misc_helper.c
@@ -XXX,XX +XXX,XX @@ uint64_t HELPER(stck)(CPUS390XState *env)
 /* SCLP service call */
 uint32_t HELPER(servc)(CPUS390XState *env, uint64_t r1, uint64_t r2)
 {
-    qemu_mutex_lock_iothread();
+    bql_lock();
     int r = sclp_service_call(env_archcpu(env), r1, r2);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     if (r < 0) {
         tcg_s390_program_interrupt(env, -r, GETPC());
     }
@@ -XXX,XX +XXX,XX @@ void HELPER(diag)(CPUS390XState *env, uint32_t r1, uint32_t r3, uint32_t num)
     switch (num) {
     case 0x500:
         /* KVM hypercall */
-        qemu_mutex_lock_iothread();
+        bql_lock();
         r = s390_virtio_hypercall(env);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         break;
     case 0x44:
         /* yield */
@@ -XXX,XX +XXX,XX @@ void HELPER(diag)(CPUS390XState *env, uint32_t r1, uint32_t r3, uint32_t num)
         break;
     case 0x308:
         /* ipl */
-        qemu_mutex_lock_iothread();
+        bql_lock();
         handle_diag_308(env, r1, r3, GETPC());
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         r = 0;
         break;
     case 0x288:
@@ -XXX,XX +XXX,XX @@ static void update_ckc_timer(CPUS390XState *env)
 
     /* stop the timer and remove pending CKC IRQs */
     timer_del(env->tod_timer);
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
     env->pending_int &= ~INTERRUPT_EXT_CLOCK_COMPARATOR;
 
     /* the tod has to exceed the ckc, this can never happen if ckc is all 1's */
@@ -XXX,XX +XXX,XX @@ void HELPER(sckc)(CPUS390XState *env, uint64_t ckc)
 {
     env->ckc = ckc;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     update_ckc_timer(env);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void tcg_s390_tod_updated(CPUState *cs, run_on_cpu_data opaque)
@@ -XXX,XX +XXX,XX @@ uint32_t HELPER(sck)(CPUS390XState *env, uint64_t tod_low)
         .low = tod_low,
     };
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     tdc->set(td, &tod, &error_abort);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     return 0;
 }
 
@@ -XXX,XX +XXX,XX @@ uint32_t HELPER(sigp)(CPUS390XState *env, uint64_t order_code, uint32_t r1,
     int cc;
 
     /* TODO: needed to inject interrupts  - push further down */
-    qemu_mutex_lock_iothread();
+    bql_lock();
     cc = handle_sigp(env, order_code & SIGP_ORDER_MASK, r1, r3);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     return cc;
 }
@@ -XXX,XX +XXX,XX @@ uint32_t HELPER(sigp)(CPUS390XState *env, uint64_t order_code, uint32_t r1,
 void HELPER(xsch)(CPUS390XState *env, uint64_t r1)
 {
     S390CPU *cpu = env_archcpu(env);
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ioinst_handle_xsch(cpu, r1, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(csch)(CPUS390XState *env, uint64_t r1)
 {
     S390CPU *cpu = env_archcpu(env);
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ioinst_handle_csch(cpu, r1, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(hsch)(CPUS390XState *env, uint64_t r1)
 {
     S390CPU *cpu = env_archcpu(env);
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ioinst_handle_hsch(cpu, r1, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(msch)(CPUS390XState *env, uint64_t r1, uint64_t inst)
 {
     S390CPU *cpu = env_archcpu(env);
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ioinst_handle_msch(cpu, r1, inst >> 16, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(rchp)(CPUS390XState *env, uint64_t r1)
 {
     S390CPU *cpu = env_archcpu(env);
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ioinst_handle_rchp(cpu, r1, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(rsch)(CPUS390XState *env, uint64_t r1)
 {
     S390CPU *cpu = env_archcpu(env);
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ioinst_handle_rsch(cpu, r1, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(sal)(CPUS390XState *env, uint64_t r1)
 {
     S390CPU *cpu = env_archcpu(env);
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ioinst_handle_sal(cpu, r1, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(schm)(CPUS390XState *env, uint64_t r1, uint64_t r2, uint64_t inst)
 {
     S390CPU *cpu = env_archcpu(env);
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ioinst_handle_schm(cpu, r1, r2, inst >> 16, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(ssch)(CPUS390XState *env, uint64_t r1, uint64_t inst)
 {
     S390CPU *cpu = env_archcpu(env);
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ioinst_handle_ssch(cpu, r1, inst >> 16, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(stcrw)(CPUS390XState *env, uint64_t inst)
 {
     S390CPU *cpu = env_archcpu(env);
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ioinst_handle_stcrw(cpu, inst >> 16, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(stsch)(CPUS390XState *env, uint64_t r1, uint64_t inst)
 {
     S390CPU *cpu = env_archcpu(env);
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ioinst_handle_stsch(cpu, r1, inst >> 16, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 uint32_t HELPER(tpi)(CPUS390XState *env, uint64_t addr)
@@ -XXX,XX +XXX,XX @@ uint32_t HELPER(tpi)(CPUS390XState *env, uint64_t addr)
         tcg_s390_program_interrupt(env, PGM_SPECIFICATION, ra);
     }
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     io = qemu_s390_flic_dequeue_io(flic, env->cregs[6]);
     if (!io) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
         return 0;
     }
 
@@ -XXX,XX +XXX,XX @@ uint32_t HELPER(tpi)(CPUS390XState *env, uint64_t addr)
         if (s390_cpu_virt_mem_write(cpu, addr, 0, &intc, sizeof(intc))) {
             /* writing failed, reinject and properly clean up */
             s390_io_interrupt(io->id, io->nr, io->parm, io->word);
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             g_free(io);
             s390_cpu_virt_mem_handle_exc(cpu, ra);
             return 0;
@@ -XXX,XX +XXX,XX @@ uint32_t HELPER(tpi)(CPUS390XState *env, uint64_t addr)
     }
 
     g_free(io);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     return 1;
 }
 
 void HELPER(tsch)(CPUS390XState *env, uint64_t r1, uint64_t inst)
 {
     S390CPU *cpu = env_archcpu(env);
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ioinst_handle_tsch(cpu, r1, inst >> 16, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(chsc)(CPUS390XState *env, uint64_t inst)
 {
     S390CPU *cpu = env_archcpu(env);
-    qemu_mutex_lock_iothread();
+    bql_lock();
     ioinst_handle_chsc(cpu, inst >> 16, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 #endif
 
@@ -XXX,XX +XXX,XX @@ void HELPER(clp)(CPUS390XState *env, uint32_t r2)
 {
     S390CPU *cpu = env_archcpu(env);
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     clp_service_call(cpu, r2, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(pcilg)(CPUS390XState *env, uint32_t r1, uint32_t r2)
 {
     S390CPU *cpu = env_archcpu(env);
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     pcilg_service_call(cpu, r1, r2, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(pcistg)(CPUS390XState *env, uint32_t r1, uint32_t r2)
 {
     S390CPU *cpu = env_archcpu(env);
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     pcistg_service_call(cpu, r1, r2, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(stpcifc)(CPUS390XState *env, uint32_t r1, uint64_t fiba,
@@ -XXX,XX +XXX,XX @@ void HELPER(stpcifc)(CPUS390XState *env, uint32_t r1, uint64_t fiba,
 {
     S390CPU *cpu = env_archcpu(env);
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     stpcifc_service_call(cpu, r1, fiba, ar, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(sic)(CPUS390XState *env, uint64_t r1, uint64_t r3)
@@ -XXX,XX +XXX,XX @@ void HELPER(sic)(CPUS390XState *env, uint64_t r1, uint64_t r3)
     S390CPU *cpu = env_archcpu(env);
     int r;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     r = css_do_sic(cpu, (r3 >> 27) & 0x7, r1 & 0xffff);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     /* css_do_sic() may actually return a PGM_xxx value to inject */
     if (r) {
         tcg_s390_program_interrupt(env, -r, GETPC());
@@ -XXX,XX +XXX,XX @@ void HELPER(rpcit)(CPUS390XState *env, uint32_t r1, uint32_t r2)
 {
     S390CPU *cpu = env_archcpu(env);
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     rpcit_service_call(cpu, r1, r2, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(pcistb)(CPUS390XState *env, uint32_t r1, uint32_t r3,
@@ -XXX,XX +XXX,XX @@ void HELPER(pcistb)(CPUS390XState *env, uint32_t r1, uint32_t r3,
 {
     S390CPU *cpu = env_archcpu(env);
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     pcistb_service_call(cpu, r1, r3, gaddr, ar, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(mpcifc)(CPUS390XState *env, uint32_t r1, uint64_t fiba,
@@ -XXX,XX +XXX,XX @@ void HELPER(mpcifc)(CPUS390XState *env, uint32_t r1, uint64_t fiba,
 {
     S390CPU *cpu = env_archcpu(env);
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     mpcifc_service_call(cpu, r1, fiba, ar, GETPC());
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 #endif
diff --git a/target/sparc/int32_helper.c b/target/sparc/int32_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/sparc/int32_helper.c
+++ b/target/sparc/int32_helper.c
@@ -XXX,XX +XXX,XX @@ void cpu_check_irqs(CPUSPARCState *env)
     CPUState *cs;
 
     /* We should be holding the BQL before we mess with IRQs */
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
 
     if (env->pil_in && (env->interrupt_index == 0 ||
                         (env->interrupt_index & ~15) == TT_EXTINT)) {
diff --git a/target/sparc/int64_helper.c b/target/sparc/int64_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/sparc/int64_helper.c
+++ b/target/sparc/int64_helper.c
@@ -XXX,XX +XXX,XX @@ void cpu_check_irqs(CPUSPARCState *env)
                   (env->softint & ~(SOFTINT_TIMER | SOFTINT_STIMER));
 
     /* We should be holding the BQL before we mess with IRQs */
-    g_assert(qemu_mutex_iothread_locked());
+    g_assert(bql_locked());
 
     /* TT_IVEC has a higher priority (16) than TT_EXTINT (31..17) */
     if (env->ivec_status & 0x20) {
@@ -XXX,XX +XXX,XX @@ static bool do_modify_softint(CPUSPARCState *env, uint32_t value)
         env->softint = value;
 #if !defined(CONFIG_USER_ONLY)
         if (cpu_interrupts_enabled(env)) {
-            qemu_mutex_lock_iothread();
+            bql_lock();
             cpu_check_irqs(env);
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
         }
 #endif
         return true;
diff --git a/target/sparc/win_helper.c b/target/sparc/win_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/sparc/win_helper.c
+++ b/target/sparc/win_helper.c
@@ -XXX,XX +XXX,XX @@ void helper_wrpsr(CPUSPARCState *env, target_ulong new_psr)
         cpu_raise_exception_ra(env, TT_ILL_INSN, GETPC());
     } else {
         /* cpu_put_psr may trigger interrupts, hence BQL */
-        qemu_mutex_lock_iothread();
+        bql_lock();
         cpu_put_psr(env, new_psr);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 }
 
@@ -XXX,XX +XXX,XX @@ void helper_wrpstate(CPUSPARCState *env, target_ulong new_state)
 
 #if !defined(CONFIG_USER_ONLY)
     if (cpu_interrupts_enabled(env)) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
         cpu_check_irqs(env);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 #endif
 }
@@ -XXX,XX +XXX,XX @@ void helper_wrpil(CPUSPARCState *env, target_ulong new_pil)
     env->psrpil = new_pil;
 
     if (cpu_interrupts_enabled(env)) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
         cpu_check_irqs(env);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 #endif
 }
@@ -XXX,XX +XXX,XX @@ void helper_done(CPUSPARCState *env)
 
 #if !defined(CONFIG_USER_ONLY)
     if (cpu_interrupts_enabled(env)) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
         cpu_check_irqs(env);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 #endif
 }
@@ -XXX,XX +XXX,XX @@ void helper_retry(CPUSPARCState *env)
 
 #if !defined(CONFIG_USER_ONLY)
     if (cpu_interrupts_enabled(env)) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
         cpu_check_irqs(env);
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 #endif
 }
diff --git a/target/xtensa/exc_helper.c b/target/xtensa/exc_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/xtensa/exc_helper.c
+++ b/target/xtensa/exc_helper.c
@@ -XXX,XX +XXX,XX @@ void HELPER(waiti)(CPUXtensaState *env, uint32_t pc, uint32_t intlevel)
     env->sregs[PS] = (env->sregs[PS] & ~PS_INTLEVEL) |
         (intlevel << PS_INTLEVEL_SHIFT);
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     check_interrupts(env);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     if (env->pending_irq_level) {
         cpu_loop_exit(cpu);
@@ -XXX,XX +XXX,XX @@ void HELPER(waiti)(CPUXtensaState *env, uint32_t pc, uint32_t intlevel)
 
 void HELPER(check_interrupts)(CPUXtensaState *env)
 {
-    qemu_mutex_lock_iothread();
+    bql_lock();
     check_interrupts(env);
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 }
 
 void HELPER(intset)(CPUXtensaState *env, uint32_t v)
diff --git a/ui/spice-core.c b/ui/spice-core.c
index XXXXXXX..XXXXXXX 100644
--- a/ui/spice-core.c
+++ b/ui/spice-core.c
@@ -XXX,XX +XXX,XX @@ static void channel_event(int event, SpiceChannelEventInfo *info)
      */
     bool need_lock = !qemu_thread_is_self(&me);
     if (need_lock) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
     }
 
     if (info->flags & SPICE_CHANNEL_EVENT_FLAG_ADDR_EXT) {
@@ -XXX,XX +XXX,XX @@ static void channel_event(int event, SpiceChannelEventInfo *info)
     }
 
     if (need_lock) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 
     qapi_free_SpiceServerInfo(server);
diff --git a/util/async.c b/util/async.c
index XXXXXXX..XXXXXXX 100644
--- a/util/async.c
+++ b/util/async.c
@@ -XXX,XX +XXX,XX @@ AioContext *qemu_get_current_aio_context(void)
     if (ctx) {
         return ctx;
     }
-    if (qemu_mutex_iothread_locked()) {
+    if (bql_locked()) {
         /* Possibly in a vCPU thread.  */
         return qemu_get_aio_context();
     }
diff --git a/util/main-loop.c b/util/main-loop.c
index XXXXXXX..XXXXXXX 100644
--- a/util/main-loop.c
+++ b/util/main-loop.c
@@ -XXX,XX +XXX,XX @@ static int os_host_main_loop_wait(int64_t timeout)
 
     glib_pollfds_fill(&timeout);
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     replay_mutex_unlock();
 
     ret = qemu_poll_ns((GPollFD *)gpollfds->data, gpollfds->len, timeout);
 
     replay_mutex_lock();
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     glib_pollfds_poll();
 
@@ -XXX,XX +XXX,XX @@ static int os_host_main_loop_wait(int64_t timeout)
 
     poll_timeout_ns = qemu_soonest_timeout(poll_timeout_ns, timeout);
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
 
     replay_mutex_unlock();
 
@@ -XXX,XX +XXX,XX @@ static int os_host_main_loop_wait(int64_t timeout)
 
     replay_mutex_lock();
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
     if (g_poll_ret > 0) {
         for (i = 0; i < w->num; i++) {
             w->revents[i] = poll_fds[n_poll_fds + i].revents;
diff --git a/util/qsp.c b/util/qsp.c
index XXXXXXX..XXXXXXX 100644
--- a/util/qsp.c
+++ b/util/qsp.c
@@ -XXX,XX +XXX,XX @@ static const char * const qsp_typenames[] = {
     [QSP_CONDVAR]   = "condvar",
 };
 
-QemuMutexLockFunc qemu_bql_mutex_lock_func = qemu_mutex_lock_impl;
+QemuMutexLockFunc bql_mutex_lock_func = qemu_mutex_lock_impl;
 QemuMutexLockFunc qemu_mutex_lock_func = qemu_mutex_lock_impl;
 QemuMutexTrylockFunc qemu_mutex_trylock_func = qemu_mutex_trylock_impl;
 QemuRecMutexLockFunc qemu_rec_mutex_lock_func = qemu_rec_mutex_lock_impl;
@@ -XXX,XX +XXX,XX @@ void qsp_enable(void)
 {
     qatomic_set(&qemu_mutex_lock_func, qsp_mutex_lock);
     qatomic_set(&qemu_mutex_trylock_func, qsp_mutex_trylock);
-    qatomic_set(&qemu_bql_mutex_lock_func, qsp_bql_mutex_lock);
+    qatomic_set(&bql_mutex_lock_func, qsp_bql_mutex_lock);
     qatomic_set(&qemu_rec_mutex_lock_func, qsp_rec_mutex_lock);
     qatomic_set(&qemu_rec_mutex_trylock_func, qsp_rec_mutex_trylock);
     qatomic_set(&qemu_cond_wait_func, qsp_cond_wait);
@@ -XXX,XX +XXX,XX @@ void qsp_disable(void)
 {
     qatomic_set(&qemu_mutex_lock_func, qemu_mutex_lock_impl);
     qatomic_set(&qemu_mutex_trylock_func, qemu_mutex_trylock_impl);
-    qatomic_set(&qemu_bql_mutex_lock_func, qemu_mutex_lock_impl);
+    qatomic_set(&bql_mutex_lock_func, qemu_mutex_lock_impl);
     qatomic_set(&qemu_rec_mutex_lock_func, qemu_rec_mutex_lock_impl);
     qatomic_set(&qemu_rec_mutex_trylock_func, qemu_rec_mutex_trylock_impl);
     qatomic_set(&qemu_cond_wait_func, qemu_cond_wait_impl);
diff --git a/util/rcu.c b/util/rcu.c
index XXXXXXX..XXXXXXX 100644
--- a/util/rcu.c
+++ b/util/rcu.c
@@ -XXX,XX +XXX,XX @@ static void *call_rcu_thread(void *opaque)
 
         qatomic_sub(&rcu_call_count, n);
         synchronize_rcu();
-        qemu_mutex_lock_iothread();
+        bql_lock();
         while (n > 0) {
             node = try_dequeue();
             while (!node) {
-                qemu_mutex_unlock_iothread();
+                bql_unlock();
                 qemu_event_reset(&rcu_call_ready_event);
                 node = try_dequeue();
                 if (!node) {
                     qemu_event_wait(&rcu_call_ready_event);
                     node = try_dequeue();
                 }
-                qemu_mutex_lock_iothread();
+                bql_lock();
             }
 
             n--;
             node->func(node);
         }
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
     abort();
 }
@@ -XXX,XX +XXX,XX @@ static void drain_rcu_callback(struct rcu_head *node)
 void drain_call_rcu(void)
 {
     struct rcu_drain rcu_drain;
-    bool locked = qemu_mutex_iothread_locked();
+    bool locked = bql_locked();
 
     memset(&rcu_drain, 0, sizeof(struct rcu_drain));
     qemu_event_init(&rcu_drain.drain_complete_event, false);
 
     if (locked) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 
 
@@ -XXX,XX +XXX,XX @@ void drain_call_rcu(void)
     qatomic_dec(&in_drain_call_rcu);
 
     if (locked) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
     }
 
 }
diff --git a/audio/coreaudio.m b/audio/coreaudio.m
index XXXXXXX..XXXXXXX 100644
--- a/audio/coreaudio.m
+++ b/audio/coreaudio.m
@@ -XXX,XX +XXX,XX @@ static OSStatus handle_voice_change(
 {
     coreaudioVoiceOut *core = in_client_data;
 
-    qemu_mutex_lock_iothread();
+    bql_lock();
 
     if (core->outputDeviceID) {
         fini_out_device(core);
@@ -XXX,XX +XXX,XX @@ static OSStatus handle_voice_change(
         update_device_playback_state(core);
     }
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     return 0;
 }
 
diff --git a/memory_ldst.c.inc b/memory_ldst.c.inc
index XXXXXXX..XXXXXXX 100644
--- a/memory_ldst.c.inc
+++ b/memory_ldst.c.inc
@@ -XXX,XX +XXX,XX @@ static inline uint32_t glue(address_space_ldl_internal, SUFFIX)(ARG1_DECL,
         *result = r;
     }
     if (release_lock) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
     RCU_READ_UNLOCK();
     return val;
@@ -XXX,XX +XXX,XX @@ static inline uint64_t glue(address_space_ldq_internal, SUFFIX)(ARG1_DECL,
         *result = r;
     }
     if (release_lock) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
     RCU_READ_UNLOCK();
     return val;
@@ -XXX,XX +XXX,XX @@ uint8_t glue(address_space_ldub, SUFFIX)(ARG1_DECL,
         *result = r;
     }
     if (release_lock) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
     RCU_READ_UNLOCK();
     return val;
@@ -XXX,XX +XXX,XX @@ static inline uint16_t glue(address_space_lduw_internal, SUFFIX)(ARG1_DECL,
         *result = r;
     }
     if (release_lock) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
     RCU_READ_UNLOCK();
     return val;
@@ -XXX,XX +XXX,XX @@ void glue(address_space_stl_notdirty, SUFFIX)(ARG1_DECL,
         *result = r;
     }
     if (release_lock) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
     RCU_READ_UNLOCK();
 }
@@ -XXX,XX +XXX,XX @@ static inline void glue(address_space_stl_internal, SUFFIX)(ARG1_DECL,
         *result = r;
     }
     if (release_lock) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
     RCU_READ_UNLOCK();
 }
@@ -XXX,XX +XXX,XX @@ void glue(address_space_stb, SUFFIX)(ARG1_DECL,
         *result = r;
     }
     if (release_lock) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
     RCU_READ_UNLOCK();
 }
@@ -XXX,XX +XXX,XX @@ static inline void glue(address_space_stw_internal, SUFFIX)(ARG1_DECL,
         *result = r;
     }
     if (release_lock) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
     RCU_READ_UNLOCK();
 }
@@ -XXX,XX +XXX,XX @@ static void glue(address_space_stq_internal, SUFFIX)(ARG1_DECL,
         *result = r;
     }
     if (release_lock) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
     RCU_READ_UNLOCK();
 }
diff --git a/target/i386/hvf/README.md b/target/i386/hvf/README.md
index XXXXXXX..XXXXXXX 100644
--- a/target/i386/hvf/README.md
+++ b/target/i386/hvf/README.md
@@ -XXX,XX +XXX,XX @@ These sources (and ../hvf-all.c) are adapted from Veertu Inc's vdhh (Veertu Desk
 
 1. Adapt to our current QEMU's `CPUState` structure and `address_space_rw` API; many struct members have been moved around (emulated x86 state, xsave_buf) due to historical differences + QEMU needing to handle more emulation targets.
 2. Removal of `apic_page` and hyperv-related functionality.
-3. More relaxed use of `qemu_mutex_lock_iothread`.
+3. More relaxed use of `bql_lock`.
diff --git a/ui/cocoa.m b/ui/cocoa.m
index XXXXXXX..XXXXXXX 100644
--- a/ui/cocoa.m
+++ b/ui/cocoa.m
@@ -XXX,XX +XXX,XX @@ static void cocoa_switch(DisplayChangeListener *dcl,
 typedef void (^CodeBlock)(void);
 typedef bool (^BoolCodeBlock)(void);
 
-static void with_iothread_lock(CodeBlock block)
+static void with_bql(CodeBlock block)
 {
-    bool locked = qemu_mutex_iothread_locked();
+    bool locked = bql_locked();
     if (!locked) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
     }
     block();
     if (!locked) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
 }
 
-static bool bool_with_iothread_lock(BoolCodeBlock block)
+static bool bool_with_bql(BoolCodeBlock block)
 {
-    bool locked = qemu_mutex_iothread_locked();
+    bool locked = bql_locked();
     bool val;
 
     if (!locked) {
-        qemu_mutex_lock_iothread();
+        bql_lock();
     }
     val = block();
     if (!locked) {
-        qemu_mutex_unlock_iothread();
+        bql_unlock();
     }
     return val;
 }
@@ -XXX,XX +XXX,XX @@ - (void) updateUIInfo
         return;
     }
 
-    with_iothread_lock(^{
+    with_bql(^{
         [self updateUIInfoLocked];
     });
 }
@@ -XXX,XX +XXX,XX @@ - (void) handleMonitorInput:(NSEvent *)event
 
 - (bool) handleEvent:(NSEvent *)event
 {
-    return bool_with_iothread_lock(^{
+    return bool_with_bql(^{
         return [self handleEventLocked:event];
     });
 }
@@ -XXX,XX +XXX,XX @@ - (QEMUScreen) gscreen {return screen;}
  */
 - (void) raiseAllKeys
 {
-    with_iothread_lock(^{
+    with_bql(^{
         qkbd_state_lift_all_keys(kbd);
     });
 }
@@ -XXX,XX +XXX,XX @@ - (void)applicationWillTerminate:(NSNotification *)aNotification
 {
     COCOA_DEBUG("QemuCocoaAppController: applicationWillTerminate\n");
 
-    with_iothread_lock(^{
+    with_bql(^{
         shutdown_action = SHUTDOWN_ACTION_POWEROFF;
         qemu_system_shutdown_request(SHUTDOWN_CAUSE_HOST_UI);
     });
@@ -XXX,XX +XXX,XX @@ - (void)displayConsole:(id)sender
 /* Pause the guest */
 - (void)pauseQEMU:(id)sender
 {
-    with_iothread_lock(^{
+    with_bql(^{
         qmp_stop(NULL);
     });
     [sender setEnabled: NO];
@@ -XXX,XX +XXX,XX @@ - (void)pauseQEMU:(id)sender
 /* Resume running the guest operating system */
 - (void)resumeQEMU:(id) sender
 {
-    with_iothread_lock(^{
+    with_bql(^{
         qmp_cont(NULL);
     });
     [sender setEnabled: NO];
@@ -XXX,XX +XXX,XX @@ - (void)removePause
 /* Restarts QEMU */
 - (void)restartQEMU:(id)sender
 {
-    with_iothread_lock(^{
+    with_bql(^{
         qmp_system_reset(NULL);
     });
 }
@@ -XXX,XX +XXX,XX @@ - (void)restartQEMU:(id)sender
 /* Powers down QEMU */
 - (void)powerDownQEMU:(id)sender
 {
-    with_iothread_lock(^{
+    with_bql(^{
         qmp_system_powerdown(NULL);
     });
 }
@@ -XXX,XX +XXX,XX @@ - (void)ejectDeviceMedia:(id)sender
     }
 
     __block Error *err = NULL;
-    with_iothread_lock(^{
+    with_bql(^{
         qmp_eject([drive cStringUsingEncoding: NSASCIIStringEncoding],
                   NULL, false, false, &err);
     });
@@ -XXX,XX +XXX,XX @@ - (void)changeDeviceMedia:(id)sender
         }
 
         __block Error *err = NULL;
-        with_iothread_lock(^{
+        with_bql(^{
             qmp_blockdev_change_medium([drive cStringUsingEncoding:
                                                   NSASCIIStringEncoding],
                                        NULL,
@@ -XXX,XX +XXX,XX @@ - (void)adjustSpeed:(id)sender
     // get the throttle percentage
     throttle_pct = [sender tag];
 
-    with_iothread_lock(^{
+    with_bql(^{
         cpu_throttle_set(throttle_pct);
     });
     COCOA_DEBUG("cpu throttling at %d%c\n", cpu_throttle_get_percentage(), '%');
@@ -XXX,XX +XXX,XX @@ - (void)pasteboard:(NSPasteboard *)sender provideDataForType:(NSPasteboardType)t
         return;
     }
 
-    with_iothread_lock(^{
+    with_bql(^{
         QemuClipboardInfo *info = qemu_clipboard_info_ref(cbinfo);
         qemu_event_reset(&cbevent);
         qemu_clipboard_request(info, QEMU_CLIPBOARD_TYPE_TEXT);
@@ -XXX,XX +XXX,XX @@ - (void)pasteboard:(NSPasteboard *)sender provideDataForType:(NSPasteboardType)t
         while (info == cbinfo &&
                info->types[QEMU_CLIPBOARD_TYPE_TEXT].available &&
                info->types[QEMU_CLIPBOARD_TYPE_TEXT].data == NULL) {
-            qemu_mutex_unlock_iothread();
+            bql_unlock();
             qemu_event_wait(&cbevent);
-            qemu_mutex_lock_iothread();
+            bql_lock();
         }
 
         if (info == cbinfo) {
@@ -XXX,XX +XXX,XX @@ static void cocoa_clipboard_request(QemuClipboardInfo *info,
     int status;
 
     COCOA_DEBUG("Second thread: calling qemu_default_main()\n");
-    qemu_mutex_lock_iothread();
+    bql_lock();
     status = qemu_default_main();
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     COCOA_DEBUG("Second thread: qemu_default_main() returned, exiting\n");
     [cbowner release];
     exit(status);
@@ -XXX,XX +XXX,XX @@ static int cocoa_main(void)
 
     COCOA_DEBUG("Entered %s()\n", __func__);
 
-    qemu_mutex_unlock_iothread();
+    bql_unlock();
     qemu_thread_create(&thread, "qemu_main", call_qemu_main,
                        NULL, QEMU_THREAD_DETACHED);
 
-- 
2.43.0

The name "iothread" is overloaded. Use the term Big QEMU Lock (BQL)
instead, it is already widely used and unambiguous.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-id: 20240102153529.486531-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 include/qemu/main-loop.h  | 19 +++++++++----------
 hw/i386/kvm/xen_evtchn.c  | 14 +++++++-------
 hw/i386/kvm/xen_gnttab.c  |  2 +-
 hw/mips/mips_int.c        |  2 +-
 hw/ppc/ppc.c              |  2 +-
 target/i386/kvm/xen-emu.c |  2 +-
 target/ppc/excp_helper.c  |  2 +-
 target/ppc/helper_regs.c  |  2 +-
 target/riscv/cpu_helper.c |  4 ++--
 9 files changed, 24 insertions(+), 25 deletions(-)

diff --git a/include/qemu/main-loop.h b/include/qemu/main-loop.h
index XXXXXXX..XXXXXXX 100644
--- a/include/qemu/main-loop.h
+++ b/include/qemu/main-loop.h
@@ -XXX,XX +XXX,XX @@ void bql_lock_impl(const char *file, int line);
 void bql_unlock(void);
 
 /**
- * QEMU_IOTHREAD_LOCK_GUARD
+ * BQL_LOCK_GUARD
  *
  * Wrap a block of code in a conditional bql_{lock,unlock}.
  */
-typedef struct IOThreadLockAuto IOThreadLockAuto;
+typedef struct BQLLockAuto BQLLockAuto;
 
-static inline IOThreadLockAuto *qemu_iothread_auto_lock(const char *file,
-                                                        int line)
+static inline BQLLockAuto *bql_auto_lock(const char *file, int line)
 {
     if (bql_locked()) {
         return NULL;
     }
     bql_lock_impl(file, line);
     /* Anything non-NULL causes the cleanup function to be called */
-    return (IOThreadLockAuto *)(uintptr_t)1;
+    return (BQLLockAuto *)(uintptr_t)1;
 }
 
-static inline void qemu_iothread_auto_unlock(IOThreadLockAuto *l)
+static inline void bql_auto_unlock(BQLLockAuto *l)
 {
     bql_unlock();
 }
 
-G_DEFINE_AUTOPTR_CLEANUP_FUNC(IOThreadLockAuto, qemu_iothread_auto_unlock)
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(BQLLockAuto, bql_auto_unlock)
 
-#define QEMU_IOTHREAD_LOCK_GUARD() \
-    g_autoptr(IOThreadLockAuto) _iothread_lock_auto __attribute__((unused)) \
-        = qemu_iothread_auto_lock(__FILE__, __LINE__)
+#define BQL_LOCK_GUARD() \
+    g_autoptr(BQLLockAuto) _bql_lock_auto __attribute__((unused)) \
+        = bql_auto_lock(__FILE__, __LINE__)
 
 /*
  * qemu_cond_wait_iothread: Wait on condition for the main loop mutex
diff --git a/hw/i386/kvm/xen_evtchn.c b/hw/i386/kvm/xen_evtchn.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/i386/kvm/xen_evtchn.c
+++ b/hw/i386/kvm/xen_evtchn.c
@@ -XXX,XX +XXX,XX @@ int xen_evtchn_reset_op(struct evtchn_reset *reset)
         return -ESRCH;
     }
 
-    QEMU_IOTHREAD_LOCK_GUARD();
+    BQL_LOCK_GUARD();
     return xen_evtchn_soft_reset();
 }
 
@@ -XXX,XX +XXX,XX @@ int xen_evtchn_close_op(struct evtchn_close *close)
         return -EINVAL;
     }
 
-    QEMU_IOTHREAD_LOCK_GUARD();
+    BQL_LOCK_GUARD();
     qemu_mutex_lock(&s->port_lock);
 
     ret = close_port(s, close->port, &flush_kvm_routes);
@@ -XXX,XX +XXX,XX @@ int xen_evtchn_bind_pirq_op(struct evtchn_bind_pirq *pirq)
         return -EINVAL;
     }
 
-    QEMU_IOTHREAD_LOCK_GUARD();
+    BQL_LOCK_GUARD();
 
     if (s->pirq[pirq->pirq].port) {
         return -EBUSY;
@@ -XXX,XX +XXX,XX @@ int xen_physdev_map_pirq(struct physdev_map_pirq *map)
         return -ENOTSUP;
     }
 
-    QEMU_IOTHREAD_LOCK_GUARD();
+    BQL_LOCK_GUARD();
     QEMU_LOCK_GUARD(&s->port_lock);
 
     if (map->domid != DOMID_SELF && map->domid != xen_domid) {
@@ -XXX,XX +XXX,XX @@ int xen_physdev_unmap_pirq(struct physdev_unmap_pirq *unmap)
         return -EINVAL;
     }
 
-    QEMU_IOTHREAD_LOCK_GUARD();
+    BQL_LOCK_GUARD();
     qemu_mutex_lock(&s->port_lock);
 
     if (!pirq_inuse(s, pirq)) {
@@ -XXX,XX +XXX,XX @@ int xen_physdev_eoi_pirq(struct physdev_eoi *eoi)
         return -ENOTSUP;
     }
 
-    QEMU_IOTHREAD_LOCK_GUARD();
+    BQL_LOCK_GUARD();
     QEMU_LOCK_GUARD(&s->port_lock);
 
     if (!pirq_inuse(s, pirq)) {
@@ -XXX,XX +XXX,XX @@ int xen_physdev_query_pirq(struct physdev_irq_status_query *query)
         return -ENOTSUP;
     }
 
-    QEMU_IOTHREAD_LOCK_GUARD();
+    BQL_LOCK_GUARD();
     QEMU_LOCK_GUARD(&s->port_lock);
 
     if (!pirq_inuse(s, pirq)) {
diff --git a/hw/i386/kvm/xen_gnttab.c b/hw/i386/kvm/xen_gnttab.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/i386/kvm/xen_gnttab.c
+++ b/hw/i386/kvm/xen_gnttab.c
@@ -XXX,XX +XXX,XX @@ int xen_gnttab_map_page(uint64_t idx, uint64_t gfn)
         return -EINVAL;
     }
 
-    QEMU_IOTHREAD_LOCK_GUARD();
+    BQL_LOCK_GUARD();
     QEMU_LOCK_GUARD(&s->gnt_lock);
 
     xen_overlay_do_map_page(&s->gnt_aliases[idx], gpa);
diff --git a/hw/mips/mips_int.c b/hw/mips/mips_int.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/mips/mips_int.c
+++ b/hw/mips/mips_int.c
@@ -XXX,XX +XXX,XX @@ static void cpu_mips_irq_request(void *opaque, int irq, int level)
         return;
     }
 
-    QEMU_IOTHREAD_LOCK_GUARD();
+    BQL_LOCK_GUARD();
 
     if (level) {
         env->CP0_Cause |= 1 << (irq + CP0Ca_IP);
diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/ppc/ppc.c
+++ b/hw/ppc/ppc.c
@@ -XXX,XX +XXX,XX @@ void ppc_set_irq(PowerPCCPU *cpu, int irq, int level)
     unsigned int old_pending;
 
     /* We may already have the BQL if coming from the reset path */
-    QEMU_IOTHREAD_LOCK_GUARD();
+    BQL_LOCK_GUARD();
 
     old_pending = env->pending_interrupts;
 
diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c
index XXXXXXX..XXXXXXX 100644
--- a/target/i386/kvm/xen-emu.c
+++ b/target/i386/kvm/xen-emu.c
@@ -XXX,XX +XXX,XX @@ static int xen_set_shared_info(uint64_t gfn)
     uint64_t gpa = gfn << TARGET_PAGE_BITS;
     int i, err;
 
-    QEMU_IOTHREAD_LOCK_GUARD();
+    BQL_LOCK_GUARD();
 
     /*
      * The xen_overlay device tells KVM about it too, since it had to
diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/ppc/excp_helper.c
+++ b/target/ppc/excp_helper.c
@@ -XXX,XX +XXX,XX @@ static int ppc_next_unmasked_interrupt(CPUPPCState *env)
 void ppc_maybe_interrupt(CPUPPCState *env)
 {
     CPUState *cs = env_cpu(env);
-    QEMU_IOTHREAD_LOCK_GUARD();
+    BQL_LOCK_GUARD();
 
     if (ppc_next_unmasked_interrupt(env)) {
         cpu_interrupt(cs, CPU_INTERRUPT_HARD);
diff --git a/target/ppc/helper_regs.c b/target/ppc/helper_regs.c
index XXXXXXX..XXXXXXX 100644
--- a/target/ppc/helper_regs.c
+++ b/target/ppc/helper_regs.c
@@ -XXX,XX +XXX,XX @@ void cpu_interrupt_exittb(CPUState *cs)
      * unless running with TCG.
      */
     if (tcg_enabled()) {
-        QEMU_IOTHREAD_LOCK_GUARD();
+        BQL_LOCK_GUARD();
         cpu_interrupt(cs, CPU_INTERRUPT_EXITTB);
     }
 }
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -XXX,XX +XXX,XX @@ void riscv_cpu_interrupt(CPURISCVState *env)
     uint64_t gein, vsgein = 0, vstip = 0, irqf = 0;
     CPUState *cs = env_cpu(env);
 
-    QEMU_IOTHREAD_LOCK_GUARD();
+    BQL_LOCK_GUARD();
 
     if (env->virt_enabled) {
         gein = get_field(env->hstatus, HSTATUS_VGEIN);
@@ -XXX,XX +XXX,XX @@ uint64_t riscv_cpu_update_mip(CPURISCVState *env, uint64_t mask, uint64_t value)
     /* No need to update mip for VSTIP */
     mask = ((mask == MIP_VSTIP) && env->vstime_irq) ? 0 : mask;
 
-    QEMU_IOTHREAD_LOCK_GUARD();
+    BQL_LOCK_GUARD();
 
     env->mip = (env->mip & ~mask) | (value & mask);
 
-- 
2.43.0

The name "iothread" is overloaded. Use the term Big QEMU Lock (BQL)
instead, it is already widely used and unambiguous.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-id: 20240102153529.486531-4-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 include/qemu/main-loop.h          | 10 +++++-----
 accel/tcg/tcg-accel-ops-rr.c      |  4 ++--
 hw/display/virtio-gpu.c           |  2 +-
 hw/ppc/spapr_events.c             |  2 +-
 system/cpu-throttle.c             |  2 +-
 system/cpus.c                     |  4 ++--
 target/i386/nvmm/nvmm-accel-ops.c |  2 +-
 target/i386/whpx/whpx-accel-ops.c |  2 +-
 8 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/include/qemu/main-loop.h b/include/qemu/main-loop.h
index XXXXXXX..XXXXXXX 100644
--- a/include/qemu/main-loop.h
+++ b/include/qemu/main-loop.h
@@ -XXX,XX +XXX,XX @@ G_DEFINE_AUTOPTR_CLEANUP_FUNC(BQLLockAuto, bql_auto_unlock)
         = bql_auto_lock(__FILE__, __LINE__)
 
 /*
- * qemu_cond_wait_iothread: Wait on condition for the main loop mutex
+ * qemu_cond_wait_bql: Wait on condition for the Big QEMU Lock (BQL)
  *
- * This function atomically releases the main loop mutex and causes
+ * This function atomically releases the Big QEMU Lock (BQL) and causes
  * the calling thread to block on the condition.
  */
-void qemu_cond_wait_iothread(QemuCond *cond);
+void qemu_cond_wait_bql(QemuCond *cond);
 
 /*
- * qemu_cond_timedwait_iothread: like the previous, but with timeout
+ * qemu_cond_timedwait_bql: like the previous, but with timeout
  */
-void qemu_cond_timedwait_iothread(QemuCond *cond, int ms);
+void qemu_cond_timedwait_bql(QemuCond *cond, int ms);
 
 /* internal interfaces */
 
diff --git a/accel/tcg/tcg-accel-ops-rr.c b/accel/tcg/tcg-accel-ops-rr.c
index XXXXXXX..XXXXXXX 100644
--- a/accel/tcg/tcg-accel-ops-rr.c
+++ b/accel/tcg/tcg-accel-ops-rr.c
@@ -XXX,XX +XXX,XX @@ static void rr_wait_io_event(void)
 
     while (all_cpu_threads_idle()) {
         rr_stop_kick_timer();
-        qemu_cond_wait_iothread(first_cpu->halt_cond);
+        qemu_cond_wait_bql(first_cpu->halt_cond);
     }
 
     rr_start_kick_timer();
@@ -XXX,XX +XXX,XX @@ static void *rr_cpu_thread_fn(void *arg)
 
     /* wait for initial kick-off after machine start */
     while (first_cpu->stopped) {
-        qemu_cond_wait_iothread(first_cpu->halt_cond);
+        qemu_cond_wait_bql(first_cpu->halt_cond);
 
         /* process any pending work */
         CPU_FOREACH(cpu) {
diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/display/virtio-gpu.c
+++ b/hw/display/virtio-gpu.c
@@ -XXX,XX +XXX,XX @@ void virtio_gpu_reset(VirtIODevice *vdev)
         g->reset_finished = false;
         qemu_bh_schedule(g->reset_bh);
         while (!g->reset_finished) {
-            qemu_cond_wait_iothread(&g->reset_cond);
+            qemu_cond_wait_bql(&g->reset_cond);
         }
     } else {
         virtio_gpu_reset_bh(g);
diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/ppc/spapr_events.c
+++ b/hw/ppc/spapr_events.c
@@ -XXX,XX +XXX,XX @@ void spapr_mce_req_event(PowerPCCPU *cpu, bool recovered)
             }
             return;
         }
-        qemu_cond_wait_iothread(&spapr->fwnmi_machine_check_interlock_cond);
+        qemu_cond_wait_bql(&spapr->fwnmi_machine_check_interlock_cond);
         if (spapr->fwnmi_machine_check_addr == -1) {
             /*
              * If the machine was reset while waiting for the interlock,
diff --git a/system/cpu-throttle.c b/system/cpu-throttle.c
index XXXXXXX..XXXXXXX 100644
--- a/system/cpu-throttle.c
+++ b/system/cpu-throttle.c
@@ -XXX,XX +XXX,XX @@ static void cpu_throttle_thread(CPUState *cpu, run_on_cpu_data opaque)
     endtime_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + sleeptime_ns;
     while (sleeptime_ns > 0 && !cpu->stop) {
         if (sleeptime_ns > SCALE_MS) {
-            qemu_cond_timedwait_iothread(cpu->halt_cond,
+            qemu_cond_timedwait_bql(cpu->halt_cond,
                                          sleeptime_ns / SCALE_MS);
         } else {
             bql_unlock();
diff --git a/system/cpus.c b/system/cpus.c
index XXXXXXX..XXXXXXX 100644
--- a/system/cpus.c
+++ b/system/cpus.c
@@ -XXX,XX +XXX,XX @@ void bql_unlock(void)
     qemu_mutex_unlock(&bql);
 }
 
-void qemu_cond_wait_iothread(QemuCond *cond)
+void qemu_cond_wait_bql(QemuCond *cond)
 {
     qemu_cond_wait(cond, &bql);
 }
 
-void qemu_cond_timedwait_iothread(QemuCond *cond, int ms)
+void qemu_cond_timedwait_bql(QemuCond *cond, int ms)
 {
     qemu_cond_timedwait(cond, &bql, ms);
 }
diff --git a/target/i386/nvmm/nvmm-accel-ops.c b/target/i386/nvmm/nvmm-accel-ops.c
index XXXXXXX..XXXXXXX 100644
--- a/target/i386/nvmm/nvmm-accel-ops.c
+++ b/target/i386/nvmm/nvmm-accel-ops.c
@@ -XXX,XX +XXX,XX @@ static void *qemu_nvmm_cpu_thread_fn(void *arg)
             }
         }
         while (cpu_thread_is_idle(cpu)) {
-            qemu_cond_wait_iothread(cpu->halt_cond);
+            qemu_cond_wait_bql(cpu->halt_cond);
         }
         qemu_wait_io_event_common(cpu);
     } while (!cpu->unplug || cpu_can_run(cpu));
diff --git a/target/i386/whpx/whpx-accel-ops.c b/target/i386/whpx/whpx-accel-ops.c
index XXXXXXX..XXXXXXX 100644
--- a/target/i386/whpx/whpx-accel-ops.c
+++ b/target/i386/whpx/whpx-accel-ops.c
@@ -XXX,XX +XXX,XX @@ static void *whpx_cpu_thread_fn(void *arg)
             }
         }
         while (cpu_thread_is_idle(cpu)) {
-            qemu_cond_wait_iothread(cpu->halt_cond);
+            qemu_cond_wait_bql(cpu->halt_cond);
         }
         qemu_wait_io_event_common(cpu);
     } while (!cpu->unplug || cpu_can_run(cpu));
-- 
2.43.0

The term "iothread lock" is obsolete. The APIs use Big QEMU Lock (BQL)
in their names. Update the code comments to use "BQL" instead of
"iothread lock".

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Message-id: 20240102153529.486531-5-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 docs/devel/reset.rst             |  2 +-
 hw/display/qxl.h                 |  2 +-
 include/exec/cpu-common.h        |  2 +-
 include/exec/memory.h            |  4 ++--
 include/exec/ramblock.h          |  2 +-
 include/migration/register.h     |  8 ++++----
 target/arm/internals.h           |  4 ++--
 accel/tcg/cputlb.c               |  4 ++--
 accel/tcg/tcg-accel-ops-icount.c |  2 +-
 hw/remote/mpqemu-link.c          |  2 +-
 migration/block-dirty-bitmap.c   | 10 +++++-----
 migration/block.c                | 22 +++++++++++-----------
 migration/colo.c                 |  2 +-
 migration/migration.c            |  2 +-
 migration/ram.c                  |  4 ++--
 system/physmem.c                 |  6 +++---
 target/arm/helper.c              |  2 +-
 ui/spice-core.c                  |  2 +-
 util/rcu.c                       |  2 +-
 audio/coreaudio.m                |  4 ++--
 ui/cocoa.m                       |  6 +++---
 21 files changed, 47 insertions(+), 47 deletions(-)

diff --git a/docs/devel/reset.rst b/docs/devel/reset.rst
index XXXXXXX..XXXXXXX 100644
--- a/docs/devel/reset.rst
+++ b/docs/devel/reset.rst
@@ -XXX,XX +XXX,XX @@ Triggering reset
 
 This section documents the APIs which "users" of a resettable object should use
 to control it. All resettable control functions must be called while holding
-the iothread lock.
+the BQL.
 
 You can apply a reset to an object using ``resettable_assert_reset()``. You need
 to call ``resettable_release_reset()`` to release the object from reset. To
diff --git a/hw/display/qxl.h b/hw/display/qxl.h
index XXXXXXX..XXXXXXX 100644
--- a/hw/display/qxl.h
+++ b/hw/display/qxl.h
@@ -XXX,XX +XXX,XX @@ OBJECT_DECLARE_SIMPLE_TYPE(PCIQXLDevice, PCI_QXL)
  *
  * Use with care; by the time this function returns, the returned pointer is
  * not protected by RCU anymore.  If the caller is not within an RCU critical
- * section and does not hold the iothread lock, it must have other means of
+ * section and does not hold the BQL, it must have other means of
  * protecting the pointer, such as a reference to the region that includes
  * the incoming ram_addr_t.
  *
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index XXXXXXX..XXXXXXX 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -XXX,XX +XXX,XX @@ RAMBlock *qemu_ram_block_by_name(const char *name);
  *
  * By the time this function returns, the returned pointer is not protected
  * by RCU anymore.  If the caller is not within an RCU critical section and
- * does not hold the iothread lock, it must have other means of protecting the
+ * does not hold the BQL, it must have other means of protecting the
  * pointer, such as a reference to the memory region that owns the RAMBlock.
  */
 RAMBlock *qemu_ram_block_from_host(void *ptr, bool round_offset,
diff --git a/include/exec/memory.h b/include/exec/memory.h
index XXXXXXX..XXXXXXX 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -XXX,XX +XXX,XX @@ int memory_region_get_fd(MemoryRegion *mr);
  *
  * Use with care; by the time this function returns, the returned pointer is
  * not protected by RCU anymore.  If the caller is not within an RCU critical
- * section and does not hold the iothread lock, it must have other means of
+ * section and does not hold the BQL, it must have other means of
  * protecting the pointer, such as a reference to the region that includes
  * the incoming ram_addr_t.
  *
@@ -XXX,XX +XXX,XX @@ MemoryRegion *memory_region_from_host(void *ptr, ram_addr_t *offset);
  *
  * Use with care; by the time this function returns, the returned pointer is
  * not protected by RCU anymore.  If the caller is not within an RCU critical
- * section and does not hold the iothread lock, it must have other means of
+ * section and does not hold the BQL, it must have other means of
  * protecting the pointer, such as a reference to the region that includes
  * the incoming ram_addr_t.
  *
diff --git a/include/exec/ramblock.h b/include/exec/ramblock.h
index XXXXXXX..XXXXXXX 100644
--- a/include/exec/ramblock.h
+++ b/include/exec/ramblock.h
@@ -XXX,XX +XXX,XX @@ struct RAMBlock {
     ram_addr_t max_length;
     void (*resized)(const char*, uint64_t length, void *host);
     uint32_t flags;
-    /* Protected by iothread lock.  */
+    /* Protected by the BQL.  */
     char idstr[256];
     /* RCU-enabled, writes protected by the ramlist lock */
     QLIST_ENTRY(RAMBlock) next;
diff --git a/include/migration/register.h b/include/migration/register.h
index XXXXXXX..XXXXXXX 100644
--- a/include/migration/register.h
+++ b/include/migration/register.h
@@ -XXX,XX +XXX,XX @@
 #include "hw/vmstate-if.h"
 
 typedef struct SaveVMHandlers {
-    /* This runs inside the iothread lock.  */
+    /* This runs inside the BQL.  */
     SaveStateHandler *save_state;
 
     /*
@@ -XXX,XX +XXX,XX @@ typedef struct SaveVMHandlers {
     int (*save_live_complete_postcopy)(QEMUFile *f, void *opaque);
     int (*save_live_complete_precopy)(QEMUFile *f, void *opaque);
 
-    /* This runs both outside and inside the iothread lock.  */
+    /* This runs both outside and inside the BQL.  */
     bool (*is_active)(void *opaque);
     bool (*has_postcopy)(void *opaque);
 
@@ -XXX,XX +XXX,XX @@ typedef struct SaveVMHandlers {
      */
     bool (*is_active_iterate)(void *opaque);
 
-    /* This runs outside the iothread lock in the migration case, and
+    /* This runs outside the BQL in the migration case, and
      * within the lock in the savevm case.  The callback had better only
      * use data that is local to the migration thread or protected
      * by other locks.
      */
     int (*save_live_iterate)(QEMUFile *f, void *opaque);
 
-    /* This runs outside the iothread lock!  */
+    /* This runs outside the BQL!  */
     /* Note for save_live_pending:
      * must_precopy:
      * - must be migrated in precopy or in stopped state
diff --git a/target/arm/internals.h b/target/arm/internals.h
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -XXX,XX +XXX,XX @@ static inline const char *aarch32_mode_name(uint32_t psr)
  *
  * Update the CPU_INTERRUPT_VIRQ bit in cs->interrupt_request, following
  * a change to either the input VIRQ line from the GIC or the HCR_EL2.VI bit.
- * Must be called with the iothread lock held.
+ * Must be called with the BQL held.
  */
 void arm_cpu_update_virq(ARMCPU *cpu);
 
@@ -XXX,XX +XXX,XX @@ void arm_cpu_update_virq(ARMCPU *cpu);
  *
  * Update the CPU_INTERRUPT_VFIQ bit in cs->interrupt_request, following
  * a change to either the input VFIQ line from the GIC or the HCR_EL2.VF bit.
- * Must be called with the iothread lock held.
+ * Must be called with the BQL held.
  */
 void arm_cpu_update_vfiq(ARMCPU *cpu);
 
diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
index XXXXXXX..XXXXXXX 100644
--- a/accel/tcg/cputlb.c
+++ b/accel/tcg/cputlb.c
@@ -XXX,XX +XXX,XX @@ static void *atomic_mmu_lookup(CPUState *cpu, vaddr addr, MemOpIdx oi,
  * @size: number of bytes
  * @mmu_idx: virtual address context
  * @ra: return address into tcg generated code, or 0
- * Context: iothread lock held
+ * Context: BQL held
  *
  * Load @size bytes from @addr, which is memory-mapped i/o.
  * The bytes are concatenated in big-endian order with @ret_be.
@@ -XXX,XX +XXX,XX @@ static Int128 do_ld16_mmu(CPUState *cpu, vaddr addr,
  * @size: number of bytes
  * @mmu_idx: virtual address context
  * @ra: return address into tcg generated code, or 0
- * Context: iothread lock held
+ * Context: BQL held
  *
  * Store @size bytes at @addr, which is memory-mapped i/o.
  * The bytes to store are extracted in little-endian order from @val_le;
diff --git a/accel/tcg/tcg-accel-ops-icount.c b/accel/tcg/tcg-accel-ops-icount.c
index XXXXXXX..XXXXXXX 100644
--- a/accel/tcg/tcg-accel-ops-icount.c
+++ b/accel/tcg/tcg-accel-ops-icount.c
@@ -XXX,XX +XXX,XX @@ void icount_prepare_for_run(CPUState *cpu, int64_t cpu_budget)
 
     if (cpu->icount_budget == 0) {
         /*
-         * We're called without the iothread lock, so must take it while
+         * We're called without the BQL, so must take it while
          * we're calling timer handlers.
          */
         bql_lock();
diff --git a/hw/remote/mpqemu-link.c b/hw/remote/mpqemu-link.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/mpqemu-link.c
+++ b/hw/remote/mpqemu-link.c
@@ -XXX,XX +XXX,XX @@ bool mpqemu_msg_send(MPQemuMsg *msg, QIOChannel *ioc, Error **errp)
     assert(qemu_in_coroutine() || !iothread);
 
     /*
-     * Skip unlocking/locking iothread lock when the IOThread is running
+     * Skip unlocking/locking BQL when the IOThread is running
      * in co-routine context. Co-routine context is asserted above
      * for IOThread case.
      * Also skip lock handling while in a co-routine in the main context.
diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c
index XXXXXXX..XXXXXXX 100644
--- a/migration/block-dirty-bitmap.c
+++ b/migration/block-dirty-bitmap.c
@@ -XXX,XX +XXX,XX @@ static void send_bitmap_bits(QEMUFile *f, DBMSaveState *s,
     g_free(buf);
 }
 
-/* Called with iothread lock taken.  */
+/* Called with the BQL taken.  */
 static void dirty_bitmap_do_save_cleanup(DBMSaveState *s)
 {
     SaveBitmapState *dbms;
@@ -XXX,XX +XXX,XX @@ static void dirty_bitmap_do_save_cleanup(DBMSaveState *s)
     }
 }
 
-/* Called with iothread lock taken. */
+/* Called with the BQL taken. */
 static int add_bitmaps_to_list(DBMSaveState *s, BlockDriverState *bs,
                                const char *bs_name, GHashTable *alias_map)
 {
@@ -XXX,XX +XXX,XX @@ static int add_bitmaps_to_list(DBMSaveState *s, BlockDriverState *bs,
     return 0;
 }
 
-/* Called with iothread lock taken. */
+/* Called with the BQL taken. */
 static int init_dirty_bitmap_migration(DBMSaveState *s)
 {
     BlockDriverState *bs;
@@ -XXX,XX +XXX,XX @@ static int init_dirty_bitmap_migration(DBMSaveState *s)
     BlockBackend *blk;
     GHashTable *alias_map = NULL;
 
-    /* Runs in the migration thread, but holds the iothread lock */
+    /* Runs in the migration thread, but holds the BQL */
     GLOBAL_STATE_CODE();
     GRAPH_RDLOCK_GUARD_MAINLOOP();
 
@@ -XXX,XX +XXX,XX @@ static int dirty_bitmap_save_iterate(QEMUFile *f, void *opaque)
     return s->bulk_completed;
 }
 
-/* Called with iothread lock taken.  */
+/* Called with the BQL taken.  */
 
 static int dirty_bitmap_save_complete(QEMUFile *f, void *opaque)
 {
diff --git a/migration/block.c b/migration/block.c
index XXXXXXX..XXXXXXX 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -XXX,XX +XXX,XX @@ typedef struct BlkMigState {
     int prev_progress;
     int bulk_completed;
 
-    /* Lock must be taken _inside_ the iothread lock.  */
+    /* Lock must be taken _inside_ the BQL.  */
     QemuMutex lock;
 } BlkMigState;
 
@@ -XXX,XX +XXX,XX @@ static void blk_mig_unlock(void)
     qemu_mutex_unlock(&block_mig_state.lock);
 }
 
-/* Must run outside of the iothread lock during the bulk phase,
+/* Must run outside of the BQL during the bulk phase,
  * or the VM will stall.
  */
 
@@ -XXX,XX +XXX,XX @@ static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds)
     return (bmds->cur_sector >= total_sectors);
 }
 
-/* Called with iothread lock taken.  */
+/* Called with the BQL taken.  */
 
 static int set_dirty_tracking(void)
 {
@@ -XXX,XX +XXX,XX @@ fail:
     return ret;
 }
 
-/* Called with iothread lock taken.  */
+/* Called with the BQL taken.  */
 
 static void unset_dirty_tracking(void)
 {
@@ -XXX,XX +XXX,XX @@ static void blk_mig_reset_dirty_cursor(void)
     }
 }
 
-/* Called with iothread lock taken.  */
+/* Called with the BQL taken.  */
 
 static int mig_save_device_dirty(QEMUFile *f, BlkMigDevState *bmds,
                                  int is_async)
@@ -XXX,XX +XXX,XX @@ error:
     return ret;
 }
 
-/* Called with iothread lock taken.
+/* Called with the BQL taken.
  *
  * return value:
  * 0: too much data for max_downtime
@@ -XXX,XX +XXX,XX @@ static int flush_blks(QEMUFile *f)
     return ret;
 }
 
-/* Called with iothread lock taken.  */
+/* Called with the BQL taken.  */
 
 static int64_t get_remaining_dirty(void)
 {
@@ -XXX,XX +XXX,XX @@ static int64_t get_remaining_dirty(void)
 
 
 
-/* Called with iothread lock taken.  */
+/* Called with the BQL taken.  */
 static void block_migration_cleanup_bmds(void)
 {
     BlkMigDevState *bmds;
@@ -XXX,XX +XXX,XX @@ static void block_migration_cleanup_bmds(void)
     }
 }
 
-/* Called with iothread lock taken.  */
+/* Called with the BQL taken.  */
 static void block_migration_cleanup(void *opaque)
 {
     BlkMigBlock *blk;
@@ -XXX,XX +XXX,XX @@ static int block_save_iterate(QEMUFile *f, void *opaque)
             }
             ret = 0;
         } else {
-            /* Always called with iothread lock taken for
+            /* Always called with the BQL taken for
              * simplicity, block_save_complete also calls it.
              */
             bql_lock();
@@ -XXX,XX +XXX,XX @@ static int block_save_iterate(QEMUFile *f, void *opaque)
     return (delta_bytes > 0);
 }
 
-/* Called with iothread lock taken.  */
+/* Called with the BQL taken.  */
 
 static int block_save_complete(QEMUFile *f, void *opaque)
 {
diff --git a/migration/colo.c b/migration/colo.c
index XXXXXXX..XXXXXXX 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -XXX,XX +XXX,XX @@ int coroutine_fn colo_incoming_co(void)
     qemu_thread_join(&th);
     bql_lock();
 
-    /* We hold the global iothread lock, so it is safe here */
+    /* We hold the global BQL, so it is safe here */
     colo_release_ram_cache();
 
     return 0;
diff --git a/migration/migration.c b/migration/migration.c
index XXXXXXX..XXXXXXX 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -XXX,XX +XXX,XX @@ fail:
 
 /**
  * migration_maybe_pause: Pause if required to by
- * migrate_pause_before_switchover called with the iothread locked
+ * migrate_pause_before_switchover called with the BQL locked
  * Returns: 0 on success
  */
 static int migration_maybe_pause(MigrationState *s,
diff --git a/migration/ram.c b/migration/ram.c
index XXXXXXX..XXXXXXX 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -XXX,XX +XXX,XX @@ static void ram_save_cleanup(void *opaque)
 
     /* We don't use dirty log with background snapshots */
     if (!migrate_background_snapshot()) {
-        /* caller have hold iothread lock or is in a bh, so there is
+        /* caller have hold BQL or is in a bh, so there is
          * no writing race against the migration bitmap
          */
         if (global_dirty_tracking & GLOBAL_DIRTY_MIGRATION) {
@@ -XXX,XX +XXX,XX @@ out:
  *
  * Returns zero to indicate success or negative on error
  *
- * Called with iothread lock
+ * Called with the BQL
  *
  * @f: QEMUFile where to send the data
  * @opaque: RAMState pointer
diff --git a/system/physmem.c b/system/physmem.c
index XXXXXXX..XXXXXXX 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -XXX,XX +XXX,XX @@ static RAMBlock *qemu_get_ram_block(ram_addr_t addr)
     abort();
 
 found:
-    /* It is safe to write mru_block outside the iothread lock.  This
+    /* It is safe to write mru_block outside the BQL.  This
      * is what happens:
      *
      *     mru_block = xxx
@@ -XXX,XX +XXX,XX @@ int qemu_ram_get_fd(RAMBlock *rb)
     return rb->fd;
 }
 
-/* Called with iothread lock held.  */
+/* Called with the BQL held.  */
 void qemu_ram_set_idstr(RAMBlock *new_block, const char *name, DeviceState *dev)
 {
     RAMBlock *block;
@@ -XXX,XX +XXX,XX @@ void qemu_ram_set_idstr(RAMBlock *new_block, const char *name, DeviceState *dev)
     }
 }
 
-/* Called with iothread lock held.  */
+/* Called with the BQL held.  */
 void qemu_ram_unset_idstr(RAMBlock *block)
 {
     /* FIXME: arch_init.c assumes that this is not called throughout
diff --git a/target/arm/helper.c b/target/arm/helper.c
index XXXXXXX..XXXXXXX 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -XXX,XX +XXX,XX @@ static void do_hcr_write(CPUARMState *env, uint64_t value, uint64_t valid_mask)
      * Updates to VI and VF require us to update the status of
      * virtual interrupts, which are the logical OR of these bits
      * and the state of the input lines from the GIC. (This requires
-     * that we have the iothread lock, which is done by marking the
+     * that we have the BQL, which is done by marking the
      * reginfo structs as ARM_CP_IO.)
      * Note that if a write to HCR pends a VIRQ or VFIQ it is never
      * possible for it to be taken immediately, because VIRQ and
diff --git a/ui/spice-core.c b/ui/spice-core.c
index XXXXXXX..XXXXXXX 100644
--- a/ui/spice-core.c
+++ b/ui/spice-core.c
@@ -XXX,XX +XXX,XX @@ static void channel_event(int event, SpiceChannelEventInfo *info)
      * not do that.  It isn't that easy to fix it in spice and even
      * when it is fixed we still should cover the already released
      * spice versions.  So detect that we've been called from another
-     * thread and grab the iothread lock if so before calling qemu
+     * thread and grab the BQL if so before calling qemu
      * functions.
      */
     bool need_lock = !qemu_thread_is_self(&me);
diff --git a/util/rcu.c b/util/rcu.c
index XXXXXXX..XXXXXXX 100644
--- a/util/rcu.c
+++ b/util/rcu.c
@@ -XXX,XX +XXX,XX @@ static void rcu_init_complete(void)
 
     qemu_event_init(&rcu_call_ready_event, false);
 
-    /* The caller is assumed to have iothread lock, so the call_rcu thread
+    /* The caller is assumed to have BQL, so the call_rcu thread
      * must have been quiescent even after forking, just recreate it.
      */
     qemu_thread_create(&thread, "call_rcu", call_rcu_thread,
diff --git a/audio/coreaudio.m b/audio/coreaudio.m
index XXXXXXX..XXXXXXX 100644
--- a/audio/coreaudio.m
+++ b/audio/coreaudio.m
@@ -XXX,XX +XXX,XX @@ static ret_type glue(coreaudio_, name)args_decl             \
 #undef COREAUDIO_WRAPPER_FUNC
 
 /*
- * callback to feed audiooutput buffer. called without iothread lock.
+ * callback to feed audiooutput buffer. called without BQL.
  * allowed to lock "buf_mutex", but disallowed to have any other locks.
  */
 static OSStatus audioDeviceIOProc(
@@ -XXX,XX +XXX,XX @@ static void update_device_playback_state(coreaudioVoiceOut *core)
     }
 }
 
-/* called without iothread lock. */
+/* called without BQL. */
 static OSStatus handle_voice_change(
     AudioObjectID in_object_id,
     UInt32 in_number_addresses,
diff --git a/ui/cocoa.m b/ui/cocoa.m
index XXXXXXX..XXXXXXX 100644
--- a/ui/cocoa.m
+++ b/ui/cocoa.m
@@ -XXX,XX +XXX,XX @@ static void cocoa_switch(DisplayChangeListener *dcl,
 static QemuClipboardInfo *cbinfo;
 static QemuEvent cbevent;
 
-// Utility functions to run specified code block with iothread lock held
+// Utility functions to run specified code block with the BQL held
 typedef void (^CodeBlock)(void);
 typedef bool (^BoolCodeBlock)(void);
 
@@ -XXX,XX +XXX,XX @@ - (void) setContentDimensions
 
 - (void) updateUIInfoLocked
 {
-    /* Must be called with the iothread lock, i.e. via updateUIInfo */
+    /* Must be called with the BQL, i.e. via updateUIInfo */
     NSSize frameSize;
     QemuUIInfo info;
 
@@ -XXX,XX +XXX,XX @@ static void cocoa_display_init(DisplayState *ds, DisplayOptions *opts)
      * Create the menu entries which depend on QEMU state (for consoles
      * and removable devices). These make calls back into QEMU functions,
      * which is OK because at this point we know that the second thread
-     * holds the iothread lock and is synchronously waiting for us to
+     * holds the BQL and is synchronously waiting for us to
      * finish.
      */
     add_console_menu_entries();
-- 
2.43.0

The term "QEMU global mutex" is identical to the more widely used Big
QEMU Lock ("BQL"). Update the code comments and documentation to use
"BQL" instead of "QEMU global mutex".

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Message-id: 20240102153529.486531-6-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 docs/devel/multi-thread-tcg.rst   |  7 +++----
 docs/devel/qapi-code-gen.rst      |  2 +-
 docs/devel/replay.rst             |  2 +-
 docs/devel/multiple-iothreads.txt | 14 +++++++-------
 include/block/blockjob.h          |  6 +++---
 include/io/task.h                 |  2 +-
 include/qemu/coroutine-core.h     |  2 +-
 include/qemu/coroutine.h          |  2 +-
 hw/block/dataplane/virtio-blk.c   |  8 ++++----
 hw/block/virtio-blk.c             |  2 +-
 hw/scsi/virtio-scsi-dataplane.c   |  6 +++---
 net/tap.c                         |  2 +-
 12 files changed, 27 insertions(+), 28 deletions(-)

diff --git a/docs/devel/multi-thread-tcg.rst b/docs/devel/multi-thread-tcg.rst
index XXXXXXX..XXXXXXX 100644
--- a/docs/devel/multi-thread-tcg.rst
+++ b/docs/devel/multi-thread-tcg.rst
@@ -XXX,XX +XXX,XX @@ instruction. This could be a future optimisation.
 Emulated hardware state
 -----------------------
 
-Currently thanks to KVM work any access to IO memory is automatically
-protected by the global iothread mutex, also known as the BQL (Big
-QEMU Lock). Any IO region that doesn't use global mutex is expected to
-do its own locking.
+Currently thanks to KVM work any access to IO memory is automatically protected
+by the BQL (Big QEMU Lock). Any IO region that doesn't use the BQL is expected
+to do its own locking.
 
 However IO memory isn't the only way emulated hardware state can be
 modified. Some architectures have model specific registers that
diff --git a/docs/devel/qapi-code-gen.rst b/docs/devel/qapi-code-gen.rst
index XXXXXXX..XXXXXXX 100644
--- a/docs/devel/qapi-code-gen.rst
+++ b/docs/devel/qapi-code-gen.rst
@@ -XXX,XX +XXX,XX @@ blocking the guest and other background operations.
 Coroutine safety can be hard to prove, similar to thread safety.  Common
 pitfalls are:
 
-- The global mutex isn't held across ``qemu_coroutine_yield()``, so
+- The BQL isn't held across ``qemu_coroutine_yield()``, so
   operations that used to assume that they execute atomically may have
   to be more careful to protect against changes in the global state.
 
diff --git a/docs/devel/replay.rst b/docs/devel/replay.rst
index XXXXXXX..XXXXXXX 100644
--- a/docs/devel/replay.rst
+++ b/docs/devel/replay.rst
@@ -XXX,XX +XXX,XX @@ modes.
 Reading and writing requests are created by CPU thread of QEMU. Later these
 requests proceed to block layer which creates "bottom halves". Bottom
 halves consist of callback and its parameters. They are processed when
-main loop locks the global mutex. These locks are not synchronized with
+main loop locks the BQL. These locks are not synchronized with
 replaying process because main loop also processes the events that do not
 affect the virtual machine state (like user interaction with monitor).
 
diff --git a/docs/devel/multiple-iothreads.txt b/docs/devel/multiple-iothreads.txt
index XXXXXXX..XXXXXXX 100644
--- a/docs/devel/multiple-iothreads.txt
+++ b/docs/devel/multiple-iothreads.txt
@@ -XXX,XX +XXX,XX @@ the COPYING file in the top-level directory.
 
 
 This document explains the IOThread feature and how to write code that runs
-outside the QEMU global mutex.
+outside the BQL.
 
 The main loop and IOThreads
 ---------------------------
@@ -XXX,XX +XXX,XX @@ scalability bottleneck on hosts with many CPUs.  Work can be spread across
 several IOThreads instead of just one main loop.  When set up correctly this
 can improve I/O latency and reduce jitter seen by the guest.
 
-The main loop is also deeply associated with the QEMU global mutex, which is a
-scalability bottleneck in itself.  vCPU threads and the main loop use the QEMU
-global mutex to serialize execution of QEMU code.  This mutex is necessary
-because a lot of QEMU's code historically was not thread-safe.
+The main loop is also deeply associated with the BQL, which is a
+scalability bottleneck in itself.  vCPU threads and the main loop use the BQL
+to serialize execution of QEMU code.  This mutex is necessary because a lot of
+QEMU's code historically was not thread-safe.
 
 The fact that all I/O processing is done in a single main loop and that the
-QEMU global mutex is contended by all vCPU threads and the main loop explain
+BQL is contended by all vCPU threads and the main loop explain
 why it is desirable to place work into IOThreads.
 
 The experimental virtio-blk data-plane implementation has been benchmarked and
@@ -XXX,XX +XXX,XX @@ There are several old APIs that use the main loop AioContext:
 
 Since they implicitly work on the main loop they cannot be used in code that
 runs in an IOThread.  They might cause a crash or deadlock if called from an
-IOThread since the QEMU global mutex is not held.
+IOThread since the BQL is not held.
 
 Instead, use the AioContext functions directly (see include/block/aio.h):
  * aio_set_fd_handler() - monitor a file descriptor
diff --git a/include/block/blockjob.h b/include/block/blockjob.h
index XXXXXXX..XXXXXXX 100644
--- a/include/block/blockjob.h
+++ b/include/block/blockjob.h
@@ -XXX,XX +XXX,XX @@ typedef struct BlockJob {
 
     /**
      * Speed that was set with @block_job_set_speed.
-     * Always modified and read under QEMU global mutex (GLOBAL_STATE_CODE).
+     * Always modified and read under the BQL (GLOBAL_STATE_CODE).
      */
     int64_t speed;
 
@@ -XXX,XX +XXX,XX @@ typedef struct BlockJob {
 
     /**
      * Block other operations when block job is running.
-     * Always modified and read under QEMU global mutex (GLOBAL_STATE_CODE).
+     * Always modified and read under the BQL (GLOBAL_STATE_CODE).
      */
     Error *blocker;
 
@@ -XXX,XX +XXX,XX @@ typedef struct BlockJob {
 
     /**
      * BlockDriverStates that are involved in this block job.
-     * Always modified and read under QEMU global mutex (GLOBAL_STATE_CODE).
+     * Always modified and read under the BQL (GLOBAL_STATE_CODE).
      */
     GSList *nodes;
 } BlockJob;
diff --git a/include/io/task.h b/include/io/task.h
index XXXXXXX..XXXXXXX 100644
--- a/include/io/task.h
+++ b/include/io/task.h
@@ -XXX,XX +XXX,XX @@ typedef void (*QIOTaskWorker)(QIOTask *task,
  * lookups) to be easily run non-blocking. Reporting the
  * results in the main thread context means that the caller
  * typically does not need to be concerned about thread
- * safety wrt the QEMU global mutex.
+ * safety wrt the BQL.
  *
  * For example, the socket_listen() method will block the caller
  * while DNS lookups take place if given a name, instead of IP
diff --git a/include/qemu/coroutine-core.h b/include/qemu/coroutine-core.h
index XXXXXXX..XXXXXXX 100644
--- a/include/qemu/coroutine-core.h
+++ b/include/qemu/coroutine-core.h
@@ -XXX,XX +XXX,XX @@
  * rather than callbacks, for operations that need to give up control while
  * waiting for events to complete.
  *
- * These functions are re-entrant and may be used outside the global mutex.
+ * These functions are re-entrant and may be used outside the BQL.
  *
  * Functions that execute in coroutine context cannot be called
  * directly from normal functions.  Use @coroutine_fn to mark such
diff --git a/include/qemu/coroutine.h b/include/qemu/coroutine.h
index XXXXXXX..XXXXXXX 100644
--- a/include/qemu/coroutine.h
+++ b/include/qemu/coroutine.h
@@ -XXX,XX +XXX,XX @@
  * rather than callbacks, for operations that need to give up control while
  * waiting for events to complete.
  *
- * These functions are re-entrant and may be used outside the global mutex.
+ * These functions are re-entrant and may be used outside the BQL.
  *
  * Functions that execute in coroutine context cannot be called
  * directly from normal functions.  Use @coroutine_fn to mark such
diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -XXX,XX +XXX,XX @@ apply_vq_mapping(IOThreadVirtQueueMappingList *iothread_vq_mapping_list,
     }
 }
 
-/* Context: QEMU global mutex held */
+/* Context: BQL held */
 bool virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *conf,
                                   VirtIOBlockDataPlane **dataplane,
                                   Error **errp)
@@ -XXX,XX +XXX,XX @@ bool virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *conf,
     return true;
 }
 
-/* Context: QEMU global mutex held */
+/* Context: BQL held */
 void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s)
 {
     VirtIOBlock *vblk;
@@ -XXX,XX +XXX,XX @@ void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s)
     g_free(s);
 }
 
-/* Context: QEMU global mutex held */
+/* Context: BQL held */
 int virtio_blk_data_plane_start(VirtIODevice *vdev)
 {
     VirtIOBlock *vblk = VIRTIO_BLK(vdev);
@@ -XXX,XX +XXX,XX @@ static void virtio_blk_data_plane_stop_vq_bh(void *opaque)
     virtio_queue_host_notifier_read(host_notifier);
 }
 
-/* Context: QEMU global mutex held */
+/* Context: BQL held */
 void virtio_blk_data_plane_stop(VirtIODevice *vdev)
 {
     VirtIOBlock *vblk = VIRTIO_BLK(vdev);
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -XXX,XX +XXX,XX @@ static void virtio_blk_resize(void *opaque)
     VirtIODevice *vdev = VIRTIO_DEVICE(opaque);
 
     /*
-     * virtio_notify_config() needs to acquire the global mutex,
+     * virtio_notify_config() needs to acquire the BQL,
      * so it can't be called from an iothread. Instead, schedule
      * it to be run in the main context BH.
      */
diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/scsi/virtio-scsi-dataplane.c
+++ b/hw/scsi/virtio-scsi-dataplane.c
@@ -XXX,XX +XXX,XX @@
 #include "scsi/constants.h"
 #include "hw/virtio/virtio-bus.h"
 
-/* Context: QEMU global mutex held */
+/* Context: BQL held */
 void virtio_scsi_dataplane_setup(VirtIOSCSI *s, Error **errp)
 {
     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
@@ -XXX,XX +XXX,XX @@ static void virtio_scsi_dataplane_stop_bh(void *opaque)
     }
 }
 
-/* Context: QEMU global mutex held */
+/* Context: BQL held */
 int virtio_scsi_dataplane_start(VirtIODevice *vdev)
 {
     int i;
@@ -XXX,XX +XXX,XX @@ fail_guest_notifiers:
     return -ENOSYS;
 }
 
-/* Context: QEMU global mutex held */
+/* Context: BQL held */
 void virtio_scsi_dataplane_stop(VirtIODevice *vdev)
 {
     BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
diff --git a/net/tap.c b/net/tap.c
index XXXXXXX..XXXXXXX 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -XXX,XX +XXX,XX @@ static void tap_send(void *opaque)
 
         /*
          * When the host keeps receiving more packets while tap_send() is
-         * running we can hog the QEMU global mutex.  Limit the number of
+         * running we can hog the BQL.  Limit the number of
          * packets that are processed per tap_send() callback to prevent
          * stalling the guest.
          */
-- 
2.43.0

The following changes since commit 1214d55d1c41fbab3a9973a05085b8760647e411:

Merge remote-tracking branch 'remotes/nvme/tags/nvme-next-pull-request' into staging (2021-02-09 13:24:37 +0000)

are available in the Git repository at:

https://gitlab.com/stefanha/qemu.git tags/block-pull-request

for you to fetch changes up to eb847c42296497978942f738cd41dc29a35a49b2:

docs: fix Parallels Image "dirty bitmap" section (2021-02-10 09:23:28 +0000)

----------------------------------------------------------------
Pull request

v4:
 * Add PCI_EXPRESS Kconfig dependency to fix s390x in "multi-process: setup PCI
   host bridge for remote device" [Philippe and Thomas]

----------------------------------------------------------------

Denis V. Lunev (1):
  docs: fix Parallels Image "dirty bitmap" section

Elena Ufimtseva (8):
  multi-process: add configure and usage information
  io: add qio_channel_writev_full_all helper
  io: add qio_channel_readv_full_all_eof & qio_channel_readv_full_all
    helpers
  multi-process: define MPQemuMsg format and transmission functions
  multi-process: introduce proxy object
  multi-process: add proxy communication functions
  multi-process: Forward PCI config space acceses to the remote process
  multi-process: perform device reset in the remote process

Jagannathan Raman (11):
  memory: alloc RAM from file at offset
  multi-process: Add config option for multi-process QEMU
  multi-process: setup PCI host bridge for remote device
  multi-process: setup a machine object for remote device process
  multi-process: Initialize message handler in remote device
  multi-process: Associate fd of a PCIDevice with its object
  multi-process: setup memory manager for remote device
  multi-process: PCI BAR read/write handling for proxy & remote
    endpoints
  multi-process: Synchronize remote memory
  multi-process: create IOHUB object to handle irq
  multi-process: Retrieve PCI info from remote process

John G Johnson (1):
  multi-process: add the concept description to
    docs/devel/qemu-multiprocess

Stefan Hajnoczi (6):
  .github: point Repo Lockdown bot to GitLab repo
  gitmodules: use GitLab repos instead of qemu.org
  gitlab-ci: remove redundant GitLab repo URL command
  docs: update README to use GitLab repo URLs
  pc-bios: update mirror URLs to GitLab
  get_maintainer: update repo URL to GitLab

MAINTAINERS                               |  24 +
 README.rst                                |   4 +-
 docs/devel/index.rst                      |   1 +
 docs/devel/multi-process.rst              | 966 ++++++++++++++++++++++
 docs/system/index.rst                     |   1 +
 docs/system/multi-process.rst             |  64 ++
 docs/interop/parallels.txt                |   2 +-
 configure                                 |  10 +
 meson.build                               |   5 +-
 hw/remote/trace.h                         |   1 +
 include/exec/memory.h                     |   2 +
 include/exec/ram_addr.h                   |   4 +-
 include/hw/pci-host/remote.h              |  30 +
 include/hw/pci/pci_ids.h                  |   3 +
 include/hw/remote/iohub.h                 |  42 +
 include/hw/remote/machine.h               |  38 +
 include/hw/remote/memory.h                |  19 +
 include/hw/remote/mpqemu-link.h           |  99 +++
 include/hw/remote/proxy-memory-listener.h |  28 +
 include/hw/remote/proxy.h                 |  48 ++
 include/io/channel.h                      |  78 ++
 include/qemu/mmap-alloc.h                 |   4 +-
 include/sysemu/iothread.h                 |   6 +
 backends/hostmem-memfd.c                  |   2 +-
 hw/misc/ivshmem.c                         |   3 +-
 hw/pci-host/remote.c                      |  75 ++
 hw/remote/iohub.c                         | 119 +++
 hw/remote/machine.c                       |  80 ++
 hw/remote/memory.c                        |  65 ++
 hw/remote/message.c                       | 230 ++++++
 hw/remote/mpqemu-link.c                   | 267 ++++++
 hw/remote/proxy-memory-listener.c         | 227 +++++
 hw/remote/proxy.c                         | 379 +++++++++
 hw/remote/remote-obj.c                    | 203 +++++
 io/channel.c                              | 116 ++-
 iothread.c                                |   6 +
 softmmu/memory.c                          |   3 +-
 softmmu/physmem.c                         |  12 +-
 util/mmap-alloc.c                         |   8 +-
 util/oslib-posix.c                        |   2 +-
 .github/lockdown.yml                      |   8 +-
 .gitlab-ci.yml                            |   1 -
 .gitmodules                               |  44 +-
 Kconfig.host                              |   4 +
 hw/Kconfig                                |   1 +
 hw/meson.build                            |   1 +
 hw/pci-host/Kconfig                       |   3 +
 hw/pci-host/meson.build                   |   1 +
 hw/remote/Kconfig                         |   4 +
 hw/remote/meson.build                     |  13 +
 hw/remote/trace-events                    |   4 +
 pc-bios/README                            |   4 +-
 scripts/get_maintainer.pl                 |   2 +-
 53 files changed, 3296 insertions(+), 70 deletions(-)
 create mode 100644 docs/devel/multi-process.rst
 create mode 100644 docs/system/multi-process.rst
 create mode 100644 hw/remote/trace.h
 create mode 100644 include/hw/pci-host/remote.h
 create mode 100644 include/hw/remote/iohub.h
 create mode 100644 include/hw/remote/machine.h
 create mode 100644 include/hw/remote/memory.h
 create mode 100644 include/hw/remote/mpqemu-link.h
 create mode 100644 include/hw/remote/proxy-memory-listener.h
 create mode 100644 include/hw/remote/proxy.h
 create mode 100644 hw/pci-host/remote.c
 create mode 100644 hw/remote/iohub.c
 create mode 100644 hw/remote/machine.c
 create mode 100644 hw/remote/memory.c
 create mode 100644 hw/remote/message.c
 create mode 100644 hw/remote/mpqemu-link.c
 create mode 100644 hw/remote/proxy-memory-listener.c
 create mode 100644 hw/remote/proxy.c
 create mode 100644 hw/remote/remote-obj.c
 create mode 100644 hw/remote/Kconfig
 create mode 100644 hw/remote/meson.build
 create mode 100644 hw/remote/trace-events

-- 
2.29.2

Use the GitLab repo URL as the main repo location in order to reduce
load on qemu.org.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-id: 20210111115017.156802-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 .github/lockdown.yml | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/.github/lockdown.yml b/.github/lockdown.yml
index XXXXXXX..XXXXXXX 100644
--- a/.github/lockdown.yml
+++ b/.github/lockdown.yml
@@ -XXX,XX +XXX,XX @@ issues:
   comment: |
     Thank you for your interest in the QEMU project.
 
-    This repository is a read-only mirror of the project's master
-    repostories hosted on https://git.qemu.org/git/qemu.git.
+    This repository is a read-only mirror of the project's repostories hosted
+    at https://gitlab.com/qemu-project/qemu.git.
     The project does not process issues filed on GitHub.
 
     The project issues are tracked on Launchpad:
@@ -XXX,XX +XXX,XX @@ pulls:
   comment: |
     Thank you for your interest in the QEMU project.
 
-    This repository is a read-only mirror of the project's master
-    repostories hosted on https://git.qemu.org/git/qemu.git.
+    This repository is a read-only mirror of the project's repostories hosted
+    on https://gitlab.com/qemu-project/qemu.git.
     The project does not process merge requests filed on GitHub.
 
     QEMU welcomes contributions of code (either fixing bugs or adding new
-- 
2.29.2

qemu.org is running out of bandwidth and the QEMU project is moving
towards a gating CI on GitLab. Use the GitLab repos instead of qemu.org
(they will become mirrors).

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20210111115017.156802-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 .gitmodules | 44 ++++++++++++++++++++++----------------------
 1 file changed, 22 insertions(+), 22 deletions(-)

diff --git a/.gitmodules b/.gitmodules
index XXXXXXX..XXXXXXX 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -XXX,XX +XXX,XX @@
 [submodule "roms/seabios"]
 	path = roms/seabios
-	url = https://git.qemu.org/git/seabios.git/
+	url = https://gitlab.com/qemu-project/seabios.git/
 [submodule "roms/SLOF"]
 	path = roms/SLOF
-	url = https://git.qemu.org/git/SLOF.git
+	url = https://gitlab.com/qemu-project/SLOF.git
 [submodule "roms/ipxe"]
 	path = roms/ipxe
-	url = https://git.qemu.org/git/ipxe.git
+	url = https://gitlab.com/qemu-project/ipxe.git
 [submodule "roms/openbios"]
 	path = roms/openbios
-	url = https://git.qemu.org/git/openbios.git
+	url = https://gitlab.com/qemu-project/openbios.git
 [submodule "roms/qemu-palcode"]
 	path = roms/qemu-palcode
-	url = https://git.qemu.org/git/qemu-palcode.git
+	url = https://gitlab.com/qemu-project/qemu-palcode.git
 [submodule "roms/sgabios"]
 	path = roms/sgabios
-	url = https://git.qemu.org/git/sgabios.git
+	url = https://gitlab.com/qemu-project/sgabios.git
 [submodule "dtc"]
 	path = dtc
-	url = https://git.qemu.org/git/dtc.git
+	url = https://gitlab.com/qemu-project/dtc.git
 [submodule "roms/u-boot"]
 	path = roms/u-boot
-	url = https://git.qemu.org/git/u-boot.git
+	url = https://gitlab.com/qemu-project/u-boot.git
 [submodule "roms/skiboot"]
 	path = roms/skiboot
-	url = https://git.qemu.org/git/skiboot.git
+	url = https://gitlab.com/qemu-project/skiboot.git
 [submodule "roms/QemuMacDrivers"]
 	path = roms/QemuMacDrivers
-	url = https://git.qemu.org/git/QemuMacDrivers.git
+	url = https://gitlab.com/qemu-project/QemuMacDrivers.git
 [submodule "ui/keycodemapdb"]
 	path = ui/keycodemapdb
-	url = https://git.qemu.org/git/keycodemapdb.git
+	url = https://gitlab.com/qemu-project/keycodemapdb.git
 [submodule "capstone"]
 	path = capstone
-	url = https://git.qemu.org/git/capstone.git
+	url = https://gitlab.com/qemu-project/capstone.git
 [submodule "roms/seabios-hppa"]
 	path = roms/seabios-hppa
-	url = https://git.qemu.org/git/seabios-hppa.git
+	url = https://gitlab.com/qemu-project/seabios-hppa.git
 [submodule "roms/u-boot-sam460ex"]
 	path = roms/u-boot-sam460ex
-	url = https://git.qemu.org/git/u-boot-sam460ex.git
+	url = https://gitlab.com/qemu-project/u-boot-sam460ex.git
 [submodule "tests/fp/berkeley-testfloat-3"]
 	path = tests/fp/berkeley-testfloat-3
-	url = https://git.qemu.org/git/berkeley-testfloat-3.git
+	url = https://gitlab.com/qemu-project/berkeley-testfloat-3.git
 [submodule "tests/fp/berkeley-softfloat-3"]
 	path = tests/fp/berkeley-softfloat-3
-	url = https://git.qemu.org/git/berkeley-softfloat-3.git
+	url = https://gitlab.com/qemu-project/berkeley-softfloat-3.git
 [submodule "roms/edk2"]
 	path = roms/edk2
-	url = https://git.qemu.org/git/edk2.git
+	url = https://gitlab.com/qemu-project/edk2.git
 [submodule "slirp"]
 	path = slirp
-	url = https://git.qemu.org/git/libslirp.git
+	url = https://gitlab.com/qemu-project/libslirp.git
 [submodule "roms/opensbi"]
 	path = roms/opensbi
-	url = 	https://git.qemu.org/git/opensbi.git
+	url = 	https://gitlab.com/qemu-project/opensbi.git
 [submodule "roms/qboot"]
 	path = roms/qboot
-	url = https://git.qemu.org/git/qboot.git
+	url = https://gitlab.com/qemu-project/qboot.git
 [submodule "meson"]
 	path = meson
-	url = https://git.qemu.org/git/meson.git
+	url = https://gitlab.com/qemu-project/meson.git
 [submodule "roms/vbootrom"]
 	path = roms/vbootrom
-	url = https://git.qemu.org/git/vbootrom.git
+	url = https://gitlab.com/qemu-project/vbootrom.git
-- 
2.29.2

qemu.org is running out of bandwidth and the QEMU project is moving
towards a gating CI on GitLab. Use the GitLab repos instead of qemu.org
(they will become mirrors).

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20210111115017.156802-5-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 README.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/README.rst b/README.rst
index XXXXXXX..XXXXXXX 100644
--- a/README.rst
+++ b/README.rst
@@ -XXX,XX +XXX,XX @@ The QEMU source code is maintained under the GIT version control system.
 
 .. code-block:: shell
 
-   git clone https://git.qemu.org/git/qemu.git
+   git clone https://gitlab.com/qemu-project/qemu.git
 
 When submitting patches, one common approach is to use 'git
 format-patch' and/or 'git send-email' to format & send the mail to the
@@ -XXX,XX +XXX,XX @@ The QEMU website is also maintained under source control.
 
 .. code-block:: shell
 
-  git clone https://git.qemu.org/git/qemu-web.git
+  git clone https://gitlab.com/qemu-project/qemu-web.git
 
 * `<https://www.qemu.org/2017/02/04/the-new-qemu-website-is-up/>`_
 
-- 
2.29.2

qemu.org is running out of bandwidth and the QEMU project is moving
towards a gating CI on GitLab. Use the GitLab repos instead of qemu.org
(they will become mirrors).

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20210111115017.156802-6-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 pc-bios/README | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pc-bios/README b/pc-bios/README
index XXXXXXX..XXXXXXX 100644
--- a/pc-bios/README
+++ b/pc-bios/README
@@ -XXX,XX +XXX,XX @@
   legacy x86 software to communicate with an attached serial console as
   if a video card were attached.  The master sources reside in a subversion
   repository at http://sgabios.googlecode.com/svn/trunk.  A git mirror is
-  available at https://git.qemu.org/git/sgabios.git.
+  available at https://gitlab.com/qemu-project/sgabios.git.
 
 - The PXE roms come from the iPXE project. Built with BANNER_TIME 0.
   Sources available at http://ipxe.org.  Vendor:Device ID -> ROM mapping:
@@ -XXX,XX +XXX,XX @@
 
 - The u-boot binary for e500 comes from the upstream denx u-boot project where
   it was compiled using the qemu-ppce500 target.
-  A git mirror is available at: https://git.qemu.org/git/u-boot.git
+  A git mirror is available at: https://gitlab.com/qemu-project/u-boot.git
   The hash used to compile the current version is: 2072e72
 
 - Skiboot (https://github.com/open-power/skiboot/) is an OPAL
-- 
2.29.2

qemu.org is running out of bandwidth and the QEMU project is moving
towards a gating CI on GitLab. Use the GitLab repos instead of qemu.org
(they will become mirrors).

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20210111115017.156802-7-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 scripts/get_maintainer.pl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/get_maintainer.pl b/scripts/get_maintainer.pl
index XXXXXXX..XXXXXXX 100755
--- a/scripts/get_maintainer.pl
+++ b/scripts/get_maintainer.pl
@@ -XXX,XX +XXX,XX @@ sub vcs_exists {
 	warn("$P: No supported VCS found.  Add --nogit to options?\n");
 	warn("Using a git repository produces better results.\n");
 	warn("Try latest git repository using:\n");
-	warn("git clone https://git.qemu.org/git/qemu.git\n");
+	warn("git clone https://gitlab.com/qemu-project/qemu.git\n");
 	$printed_novcs = 1;
     }
     return 0;
-- 
2.29.2

From: John G Johnson <john.g.johnson@oracle.com>

Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 02a68adef99f5df6a380bf8fd7b90948777e411c.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 MAINTAINERS                  |   7 +
 docs/devel/index.rst         |   1 +
 docs/devel/multi-process.rst | 966 +++++++++++++++++++++++++++++++++++
 3 files changed, 974 insertions(+)
 create mode 100644 docs/devel/multi-process.rst

diff --git a/MAINTAINERS b/MAINTAINERS
index XXXXXXX..XXXXXXX 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -XXX,XX +XXX,XX @@ S: Maintained
 F: hw/semihosting/
 F: include/hw/semihosting/
 
+Multi-process QEMU
+M: Elena Ufimtseva <elena.ufimtseva@oracle.com>
+M: Jagannathan Raman <jag.raman@oracle.com>
+M: John G Johnson <john.g.johnson@oracle.com>
+S: Maintained
+F: docs/devel/multi-process.rst
+
 Build and test automation
 -------------------------
 Build and test automation
diff --git a/docs/devel/index.rst b/docs/devel/index.rst
index XXXXXXX..XXXXXXX 100644
--- a/docs/devel/index.rst
+++ b/docs/devel/index.rst
@@ -XXX,XX +XXX,XX @@ Contents:
    clocks
    qom
    block-coroutine-wrapper
+   multi-process
diff --git a/docs/devel/multi-process.rst b/docs/devel/multi-process.rst
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/docs/devel/multi-process.rst
@@ -XXX,XX +XXX,XX @@
+This is the design document for multi-process QEMU. It does not
+necessarily reflect the status of the current implementation, which
+may lack features or be considerably different from what is described
+in this document. This document is still useful as a description of
+the goals and general direction of this feature.
+
+Please refer to the following wiki for latest details:
+https://wiki.qemu.org/Features/MultiProcessQEMU
+
+Multi-process QEMU
+===================
+
+QEMU is often used as the hypervisor for virtual machines running in the
+Oracle cloud. Since one of the advantages of cloud computing is the
+ability to run many VMs from different tenants in the same cloud
+infrastructure, a guest that compromised its hypervisor could
+potentially use the hypervisor's access privileges to access data it is
+not authorized for.
+
+QEMU can be susceptible to security attacks because it is a large,
+monolithic program that provides many features to the VMs it services.
+Many of these features can be configured out of QEMU, but even a reduced
+configuration QEMU has a large amount of code a guest can potentially
+attack. Separating QEMU reduces the attack surface by aiding to
+limit each component in the system to only access the resources that
+it needs to perform its job.
+
+QEMU services
+-------------
+
+QEMU can be broadly described as providing three main services. One is a
+VM control point, where VMs can be created, migrated, re-configured, and
+destroyed. A second is to emulate the CPU instructions within the VM,
+often accelerated by HW virtualization features such as Intel's VT
+extensions. Finally, it provides IO services to the VM by emulating HW
+IO devices, such as disk and network devices.
+
+A multi-process QEMU
+~~~~~~~~~~~~~~~~~~~~
+
+A multi-process QEMU involves separating QEMU services into separate
+host processes. Each of these processes can be given only the privileges
+it needs to provide its service, e.g., a disk service could be given
+access only to the disk images it provides, and not be allowed to
+access other files, or any network devices. An attacker who compromised
+this service would not be able to use this exploit to access files or
+devices beyond what the disk service was given access to.
+
+A QEMU control process would remain, but in multi-process mode, will
+have no direct interfaces to the VM. During VM execution, it would still
+provide the user interface to hot-plug devices or live migrate the VM.
+
+A first step in creating a multi-process QEMU is to separate IO services
+from the main QEMU program, which would continue to provide CPU
+emulation. i.e., the control process would also be the CPU emulation
+process. In a later phase, CPU emulation could be separated from the
+control process.
+
+Separating IO services
+----------------------
+
+Separating IO services into individual host processes is a good place to
+begin for a couple of reasons. One is the sheer number of IO devices QEMU
+can emulate provides a large surface of interfaces which could potentially
+be exploited, and, indeed, have been a source of exploits in the past.
+Another is the modular nature of QEMU device emulation code provides
+interface points where the QEMU functions that perform device emulation
+can be separated from the QEMU functions that manage the emulation of
+guest CPU instructions. The devices emulated in the separate process are
+referred to as remote devices.
+
+QEMU device emulation
+~~~~~~~~~~~~~~~~~~~~~
+
+QEMU uses an object oriented SW architecture for device emulation code.
+Configured objects are all compiled into the QEMU binary, then objects
+are instantiated by name when used by the guest VM. For example, the
+code to emulate a device named "foo" is always present in QEMU, but its
+instantiation code is only run when the device is included in the target
+VM. (e.g., via the QEMU command line as *-device foo*)
+
+The object model is hierarchical, so device emulation code names its
+parent object (such as "pci-device" for a PCI device) and QEMU will
+instantiate a parent object before calling the device's instantiation
+code.
+
+Current separation models
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+In order to separate the device emulation code from the CPU emulation
+code, the device object code must run in a different process. There are
+a couple of existing QEMU features that can run emulation code
+separately from the main QEMU process. These are examined below.
+
+vhost user model
+^^^^^^^^^^^^^^^^
+
+Virtio guest device drivers can be connected to vhost user applications
+in order to perform their IO operations. This model uses special virtio
+device drivers in the guest and vhost user device objects in QEMU, but
+once the QEMU vhost user code has configured the vhost user application,
+mission-mode IO is performed by the application. The vhost user
+application is a daemon process that can be contacted via a known UNIX
+domain socket.
+
+vhost socket
+''''''''''''
+
+As mentioned above, one of the tasks of the vhost device object within
+QEMU is to contact the vhost application and send it configuration
+information about this device instance. As part of the configuration
+process, the application can also be sent other file descriptors over
+the socket, which then can be used by the vhost user application in
+various ways, some of which are described below.
+
+vhost MMIO store acceleration
+'''''''''''''''''''''''''''''
+
+VMs are often run using HW virtualization features via the KVM kernel
+driver. This driver allows QEMU to accelerate the emulation of guest CPU
+instructions by running the guest in a virtual HW mode. When the guest
+executes instructions that cannot be executed by virtual HW mode,
+execution returns to the KVM driver so it can inform QEMU to emulate the
+instructions in SW.
+
+One of the events that can cause a return to QEMU is when a guest device
+driver accesses an IO location. QEMU then dispatches the memory
+operation to the corresponding QEMU device object. In the case of a
+vhost user device, the memory operation would need to be sent over a
+socket to the vhost application. This path is accelerated by the QEMU
+virtio code by setting up an eventfd file descriptor that the vhost
+application can directly receive MMIO store notifications from the KVM
+driver, instead of needing them to be sent to the QEMU process first.
+
+vhost interrupt acceleration
+''''''''''''''''''''''''''''
+
+Another optimization used by the vhost application is the ability to
+directly inject interrupts into the VM via the KVM driver, again,
+bypassing the need to send the interrupt back to the QEMU process first.
+The QEMU virtio setup code configures the KVM driver with an eventfd
+that triggers the device interrupt in the guest when the eventfd is
+written. This irqfd file descriptor is then passed to the vhost user
+application program.
+
+vhost access to guest memory
+''''''''''''''''''''''''''''
+
+The vhost application is also allowed to directly access guest memory,
+instead of needing to send the data as messages to QEMU. This is also
+done with file descriptors sent to the vhost user application by QEMU.
+These descriptors can be passed to ``mmap()`` by the vhost application
+to map the guest address space into the vhost application.
+
+IOMMUs introduce another level of complexity, since the address given to
+the guest virtio device to DMA to or from is not a guest physical
+address. This case is handled by having vhost code within QEMU register
+as a listener for IOMMU mapping changes. The vhost application maintains
+a cache of IOMMMU translations: sending translation requests back to
+QEMU on cache misses, and in turn receiving flush requests from QEMU
+when mappings are purged.
+
+applicability to device separation
+''''''''''''''''''''''''''''''''''
+
+Much of the vhost model can be re-used by separated device emulation. In
+particular, the ideas of using a socket between QEMU and the device
+emulation application, using a file descriptor to inject interrupts into
+the VM via KVM, and allowing the application to ``mmap()`` the guest
+should be re used.
+
+There are, however, some notable differences between how a vhost
+application works and the needs of separated device emulation. The most
+basic is that vhost uses custom virtio device drivers which always
+trigger IO with MMIO stores. A separated device emulation model must
+work with existing IO device models and guest device drivers. MMIO loads
+break vhost store acceleration since they are synchronous - guest
+progress cannot continue until the load has been emulated. By contrast,
+stores are asynchronous, the guest can continue after the store event
+has been sent to the vhost application.
+
+Another difference is that in the vhost user model, a single daemon can
+support multiple QEMU instances. This is contrary to the security regime
+desired, in which the emulation application should only be allowed to
+access the files or devices the VM it's running on behalf of can access.
+#### qemu-io model
+
+Qemu-io is a test harness used to test changes to the QEMU block backend
+object code. (e.g., the code that implements disk images for disk driver
+emulation) Qemu-io is not a device emulation application per se, but it
+does compile the QEMU block objects into a separate binary from the main
+QEMU one. This could be useful for disk device emulation, since its
+emulation applications will need to include the QEMU block objects.
+
+New separation model based on proxy objects
+-------------------------------------------
+
+A different model based on proxy objects in the QEMU program
+communicating with remote emulation programs could provide separation
+while minimizing the changes needed to the device emulation code. The
+rest of this section is a discussion of how a proxy object model would
+work.
+
+Remote emulation processes
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The remote emulation process will run the QEMU object hierarchy without
+modification. The device emulation objects will be also be based on the
+QEMU code, because for anything but the simplest device, it would not be
+a tractable to re-implement both the object model and the many device
+backends that QEMU has.
+
+The processes will communicate with the QEMU process over UNIX domain
+sockets. The processes can be executed either as standalone processes,
+or be executed by QEMU. In both cases, the host backends the emulation
+processes will provide are specified on its command line, as they would
+be for QEMU. For example:
+
+::
+
+    disk-proc -blockdev driver=file,node-name=file0,filename=disk-file0  \
+    -blockdev driver=qcow2,node-name=drive0,file=file0
+
+would indicate process *disk-proc* uses a qcow2 emulated disk named
+*file0* as its backend.
+
+Emulation processes may emulate more than one guest controller. A common
+configuration might be to put all controllers of the same device class
+(e.g., disk, network, etc.) in a single process, so that all backends of
+the same type can be managed by a single QMP monitor.
+
+communication with QEMU
+^^^^^^^^^^^^^^^^^^^^^^^
+
+The first argument to the remote emulation process will be a Unix domain
+socket that connects with the Proxy object. This is a required argument.
+
+::
+
+    disk-proc <socket number> <backend list>
+
+remote process QMP monitor
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Remote emulation processes can be monitored via QMP, similar to QEMU
+itself. The QMP monitor socket is specified the same as for a QEMU
+process:
+
+::
+
+    disk-proc -qmp unix:/tmp/disk-mon,server
+
+can be monitored over the UNIX socket path */tmp/disk-mon*.
+
+QEMU command line
+~~~~~~~~~~~~~~~~~
+
+Each remote device emulated in a remote process on the host is
+represented as a *-device* of type *pci-proxy-dev*. A socket
+sub-option to this option specifies the Unix socket that connects
+to the remote process. An *id* sub-option is required, and it should
+be the same id as used in the remote process.
+
+::
+
+    qemu-system-x86_64 ... -device pci-proxy-dev,id=lsi0,socket=3
+
+can be used to add a device emulated in a remote process
+
+
+QEMU management of remote processes
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+QEMU is not aware of the type of type of the remote PCI device. It is
+a pass through device as far as QEMU is concerned.
+
+communication with emulation process
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+primary channel
+'''''''''''''''
+
+The primary channel (referred to as com in the code) is used to bootstrap
+the remote process. It is also used to pass on device-agnostic commands
+like reset.
+
+per-device channels
+'''''''''''''''''''
+
+Each remote device communicates with QEMU using a dedicated communication
+channel. The proxy object sets up this channel using the primary
+channel during its initialization.
+
+QEMU device proxy objects
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+QEMU has an object model based on sub-classes inherited from the
+"object" super-class. The sub-classes that are of interest here are the
+"device" and "bus" sub-classes whose child sub-classes make up the
+device tree of a QEMU emulated system.
+
+The proxy object model will use device proxy objects to replace the
+device emulation code within the QEMU process. These objects will live
+in the same place in the object and bus hierarchies as the objects they
+replace. i.e., the proxy object for an LSI SCSI controller will be a
+sub-class of the "pci-device" class, and will have the same PCI bus
+parent and the same SCSI bus child objects as the LSI controller object
+it replaces.
+
+It is worth noting that the same proxy object is used to mediate with
+all types of remote PCI devices.
+
+object initialization
+^^^^^^^^^^^^^^^^^^^^^
+
+The Proxy device objects are initialized in the exact same manner in
+which any other QEMU device would be initialized.
+
+In addition, the Proxy objects perform the following two tasks:
+- Parses the "socket" sub option and connects to the remote process
+using this channel
+- Uses the "id" sub-option to connect to the emulated device on the
+separate process
+
+class\_init
+'''''''''''
+
+The ``class_init()`` method of a proxy object will, in general behave
+similarly to the object it replaces, including setting any static
+properties and methods needed by the proxy.
+
+instance\_init / realize
+''''''''''''''''''''''''
+
+The ``instance_init()`` and ``realize()`` functions would only need to
+perform tasks related to being a proxy, such are registering its own
+MMIO handlers, or creating a child bus that other proxy devices can be
+attached to later.
+
+Other tasks will be device-specific. For example, PCI device objects
+will initialize the PCI config space in order to make a valid PCI device
+tree within the QEMU process.
+
+address space registration
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Most devices are driven by guest device driver accesses to IO addresses
+or ports. The QEMU device emulation code uses QEMU's memory region
+function calls (such as ``memory_region_init_io()``) to add callback
+functions that QEMU will invoke when the guest accesses the device's
+areas of the IO address space. When a guest driver does access the
+device, the VM will exit HW virtualization mode and return to QEMU,
+which will then lookup and execute the corresponding callback function.
+
+A proxy object would need to mirror the memory region calls the actual
+device emulator would perform in its initialization code, but with its
+own callbacks. When invoked by QEMU as a result of a guest IO operation,
+they will forward the operation to the device emulation process.
+
+PCI config space
+^^^^^^^^^^^^^^^^
+
+PCI devices also have a configuration space that can be accessed by the
+guest driver. Guest accesses to this space is not handled by the device
+emulation object, but by its PCI parent object. Much of this space is
+read-only, but certain registers (especially BAR and MSI-related ones)
+need to be propagated to the emulation process.
+
+PCI parent proxy
+''''''''''''''''
+
+One way to propagate guest PCI config accesses is to create a
+"pci-device-proxy" class that can serve as the parent of a PCI device
+proxy object. This class's parent would be "pci-device" and it would
+override the PCI parent's ``config_read()`` and ``config_write()``
+methods with ones that forward these operations to the emulation
+program.
+
+interrupt receipt
+^^^^^^^^^^^^^^^^^
+
+A proxy for a device that generates interrupts will need to create a
+socket to receive interrupt indications from the emulation process. An
+incoming interrupt indication would then be sent up to its bus parent to
+be injected into the guest. For example, a PCI device object may use
+``pci_set_irq()``.
+
+live migration
+^^^^^^^^^^^^^^
+
+The proxy will register to save and restore any *vmstate* it needs over
+a live migration event. The device proxy does not need to manage the
+remote device's *vmstate*; that will be handled by the remote process
+proxy (see below).
+
+QEMU remote device operation
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Generic device operations, such as DMA, will be performed by the remote
+process proxy by sending messages to the remote process.
+
+DMA operations
+^^^^^^^^^^^^^^
+
+DMA operations would be handled much like vhost applications do. One of
+the initial messages sent to the emulation process is a guest memory
+table. Each entry in this table consists of a file descriptor and size
+that the emulation process can ``mmap()`` to directly access guest
+memory, similar to ``vhost_user_set_mem_table()``. Note guest memory
+must be backed by file descriptors, such as when QEMU is given the
+*-mem-path* command line option.
+
+IOMMU operations
+^^^^^^^^^^^^^^^^
+
+When the emulated system includes an IOMMU, the remote process proxy in
+QEMU will need to create a socket for IOMMU requests from the emulation
+process. It will handle those requests with an
+``address_space_get_iotlb_entry()`` call. In order to handle IOMMU
+unmaps, the remote process proxy will also register as a listener on the
+device's DMA address space. When an IOMMU memory region is created
+within the DMA address space, an IOMMU notifier for unmaps will be added
+to the memory region that will forward unmaps to the emulation process
+over the IOMMU socket.
+
+device hot-plug via QMP
+^^^^^^^^^^^^^^^^^^^^^^^
+
+An QMP "device\_add" command can add a device emulated by a remote
+process. It will also have "rid" option to the command, just as the
+*-device* command line option does. The remote process may either be one
+started at QEMU startup, or be one added by the "add-process" QMP
+command described above. In either case, the remote process proxy will
+forward the new device's JSON description to the corresponding emulation
+process.
+
+live migration
+^^^^^^^^^^^^^^
+
+The remote process proxy will also register for live migration
+notifications with ``vmstate_register()``. When called to save state,
+the proxy will send the remote process a secondary socket file
+descriptor to save the remote process's device *vmstate* over. The
+incoming byte stream length and data will be saved as the proxy's
+*vmstate*. When the proxy is resumed on its new host, this *vmstate*
+will be extracted, and a secondary socket file descriptor will be sent
+to the new remote process through which it receives the *vmstate* in
+order to restore the devices there.
+
+device emulation in remote process
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The parts of QEMU that the emulation program will need include the
+object model; the memory emulation objects; the device emulation objects
+of the targeted device, and any dependent devices; and, the device's
+backends. It will also need code to setup the machine environment,
+handle requests from the QEMU process, and route machine-level requests
+(such as interrupts or IOMMU mappings) back to the QEMU process.
+
+initialization
+^^^^^^^^^^^^^^
+
+The process initialization sequence will follow the same sequence
+followed by QEMU. It will first initialize the backend objects, then
+device emulation objects. The JSON descriptions sent by the QEMU process
+will drive which objects need to be created.
+
+-  address spaces
+
+Before the device objects are created, the initial address spaces and
+memory regions must be configured with ``memory_map_init()``. This
+creates a RAM memory region object (*system\_memory*) and an IO memory
+region object (*system\_io*).
+
+-  RAM
+
+RAM memory region creation will follow how ``pc_memory_init()`` creates
+them, but must use ``memory_region_init_ram_from_fd()`` instead of
+``memory_region_allocate_system_memory()``. The file descriptors needed
+will be supplied by the guest memory table from above. Those RAM regions
+would then be added to the *system\_memory* memory region with
+``memory_region_add_subregion()``.
+
+-  PCI
+
+IO initialization will be driven by the JSON descriptions sent from the
+QEMU process. For a PCI device, a PCI bus will need to be created with
+``pci_root_bus_new()``, and a PCI memory region will need to be created
+and added to the *system\_memory* memory region with
+``memory_region_add_subregion_overlap()``. The overlap version is
+required for architectures where PCI memory overlaps with RAM memory.
+
+MMIO handling
+^^^^^^^^^^^^^
+
+The device emulation objects will use ``memory_region_init_io()`` to
+install their MMIO handlers, and ``pci_register_bar()`` to associate
+those handlers with a PCI BAR, as they do within QEMU currently.
+
+In order to use ``address_space_rw()`` in the emulation process to
+handle MMIO requests from QEMU, the PCI physical addresses must be the
+same in the QEMU process and the device emulation process. In order to
+accomplish that, guest BAR programming must also be forwarded from QEMU
+to the emulation process.
+
+interrupt injection
+^^^^^^^^^^^^^^^^^^^
+
+When device emulation wants to inject an interrupt into the VM, the
+request climbs the device's bus object hierarchy until the point where a
+bus object knows how to signal the interrupt to the guest. The details
+depend on the type of interrupt being raised.
+
+-  PCI pin interrupts
+
+On x86 systems, there is an emulated IOAPIC object attached to the root
+PCI bus object, and the root PCI object forwards interrupt requests to
+it. The IOAPIC object, in turn, calls the KVM driver to inject the
+corresponding interrupt into the VM. The simplest way to handle this in
+an emulation process would be to setup the root PCI bus driver (via
+``pci_bus_irqs()``) to send a interrupt request back to the QEMU
+process, and have the device proxy object reflect it up the PCI tree
+there.
+
+-  PCI MSI/X interrupts
+
+PCI MSI/X interrupts are implemented in HW as DMA writes to a
+CPU-specific PCI address. In QEMU on x86, a KVM APIC object receives
+these DMA writes, then calls into the KVM driver to inject the interrupt
+into the VM. A simple emulation process implementation would be to send
+the MSI DMA address from QEMU as a message at initialization, then
+install an address space handler at that address which forwards the MSI
+message back to QEMU.
+
+DMA operations
+^^^^^^^^^^^^^^
+
+When a emulation object wants to DMA into or out of guest memory, it
+first must use dma\_memory\_map() to convert the DMA address to a local
+virtual address. The emulation process memory region objects setup above
+will be used to translate the DMA address to a local virtual address the
+device emulation code can access.
+
+IOMMU
+^^^^^
+
+When an IOMMU is in use in QEMU, DMA translation uses IOMMU memory
+regions to translate the DMA address to a guest physical address before
+that physical address can be translated to a local virtual address. The
+emulation process will need similar functionality.
+
+-  IOTLB cache
+
+The emulation process will maintain a cache of recent IOMMU translations
+(the IOTLB). When the translate() callback of an IOMMU memory region is
+invoked, the IOTLB cache will be searched for an entry that will map the
+DMA address to a guest PA. On a cache miss, a message will be sent back
+to QEMU requesting the corresponding translation entry, which be both be
+used to return a guest address and be added to the cache.
+
+-  IOTLB purge
+
+The IOMMU emulation will also need to act on unmap requests from QEMU.
+These happen when the guest IOMMU driver purges an entry from the
+guest's translation table.
+
+live migration
+^^^^^^^^^^^^^^
+
+When a remote process receives a live migration indication from QEMU, it
+will set up a channel using the received file descriptor with
+``qio_channel_socket_new_fd()``. This channel will be used to create a
+*QEMUfile* that can be passed to ``qemu_save_device_state()`` to send
+the process's device state back to QEMU. This method will be reversed on
+restore - the channel will be passed to ``qemu_loadvm_state()`` to
+restore the device state.
+
+Accelerating device emulation
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The messages that are required to be sent between QEMU and the emulation
+process can add considerable latency to IO operations. The optimizations
+described below attempt to ameliorate this effect by allowing the
+emulation process to communicate directly with the kernel KVM driver.
+The KVM file descriptors created would be passed to the emulation process
+via initialization messages, much like the guest memory table is done.
+#### MMIO acceleration
+
+Vhost user applications can receive guest virtio driver stores directly
+from KVM. The issue with the eventfd mechanism used by vhost user is
+that it does not pass any data with the event indication, so it cannot
+handle guest loads or guest stores that carry store data. This concept
+could, however, be expanded to cover more cases.
+
+The expanded idea would require a new type of KVM device:
+*KVM\_DEV\_TYPE\_USER*. This device has two file descriptors: a master
+descriptor that QEMU can use for configuration, and a slave descriptor
+that the emulation process can use to receive MMIO notifications. QEMU
+would create both descriptors using the KVM driver, and pass the slave
+descriptor to the emulation process via an initialization message.
+
+data structures
+^^^^^^^^^^^^^^^
+
+-  guest physical range
+
+The guest physical range structure describes the address range that a
+device will respond to. It includes the base and length of the range, as
+well as which bus the range resides on (e.g., on an x86machine, it can
+specify whether the range refers to memory or IO addresses).
+
+A device can have multiple physical address ranges it responds to (e.g.,
+a PCI device can have multiple BARs), so the structure will also include
+an enumerated identifier to specify which of the device's ranges is
+being referred to.
+
++--------+----------------------------+
+| Name   | Description                |
++========+============================+
+| addr   | range base address         |
++--------+----------------------------+
+| len    | range length               |
++--------+----------------------------+
+| bus    | addr type (memory or IO)   |
++--------+----------------------------+
+| id     | range ID (e.g., PCI BAR)   |
++--------+----------------------------+
+
+-  MMIO request structure
+
+This structure describes an MMIO operation. It includes which guest
+physical range the MMIO was within, the offset within that range, the
+MMIO type (e.g., load or store), and its length and data. It also
+includes a sequence number that can be used to reply to the MMIO, and
+the CPU that issued the MMIO.
+
++----------+------------------------+
+| Name     | Description            |
++==========+========================+
+| rid      | range MMIO is within   |
++----------+------------------------+
+| offset   | offset withing *rid*   |
++----------+------------------------+
+| type     | e.g., load or store    |
++----------+------------------------+
+| len      | MMIO length            |
++----------+------------------------+
+| data     | store data             |
++----------+------------------------+
+| seq      | sequence ID            |
++----------+------------------------+
+
+-  MMIO request queues
+
+MMIO request queues are FIFO arrays of MMIO request structures. There
+are two queues: pending queue is for MMIOs that haven't been read by the
+emulation program, and the sent queue is for MMIOs that haven't been
+acknowledged. The main use of the second queue is to validate MMIO
+replies from the emulation program.
+
+-  scoreboard
+
+Each CPU in the VM is emulated in QEMU by a separate thread, so multiple
+MMIOs may be waiting to be consumed by an emulation program and multiple
+threads may be waiting for MMIO replies. The scoreboard would contain a
+wait queue and sequence number for the per-CPU threads, allowing them to
+be individually woken when the MMIO reply is received from the emulation
+program. It also tracks the number of posted MMIO stores to the device
+that haven't been replied to, in order to satisfy the PCI constraint
+that a load to a device will not complete until all previous stores to
+that device have been completed.
+
+-  device shadow memory
+
+Some MMIO loads do not have device side-effects. These MMIOs can be
+completed without sending a MMIO request to the emulation program if the
+emulation program shares a shadow image of the device's memory image
+with the KVM driver.
+
+The emulation program will ask the KVM driver to allocate memory for the
+shadow image, and will then use ``mmap()`` to directly access it. The
+emulation program can control KVM access to the shadow image by sending
+KVM an access map telling it which areas of the image have no
+side-effects (and can be completed immediately), and which require a
+MMIO request to the emulation program. The access map can also inform
+the KVM drive which size accesses are allowed to the image.
+
+master descriptor
+^^^^^^^^^^^^^^^^^
+
+The master descriptor is used by QEMU to configure the new KVM device.
+The descriptor would be returned by the KVM driver when QEMU issues a
+*KVM\_CREATE\_DEVICE* ``ioctl()`` with a *KVM\_DEV\_TYPE\_USER* type.
+
+KVM\_DEV\_TYPE\_USER device ops
+
+
+The *KVM\_DEV\_TYPE\_USER* operations vector will be registered by a
+``kvm_register_device_ops()`` call when the KVM system in initialized by
+``kvm_init()``. These device ops are called by the KVM driver when QEMU
+executes certain ``ioctl()`` operations on its KVM file descriptor. They
+include:
+
+-  create
+
+This routine is called when QEMU issues a *KVM\_CREATE\_DEVICE*
+``ioctl()`` on its per-VM file descriptor. It will allocate and
+initialize a KVM user device specific data structure, and assign the
+*kvm\_device* private field to it.
+
+-  ioctl
+
+This routine is invoked when QEMU issues an ``ioctl()`` on the master
+descriptor. The ``ioctl()`` commands supported are defined by the KVM
+device type. *KVM\_DEV\_TYPE\_USER* ones will need several commands:
+
+*KVM\_DEV\_USER\_SLAVE\_FD* creates the slave file descriptor that will
+be passed to the device emulation program. Only one slave can be created
+by each master descriptor. The file operations performed by this
+descriptor are described below.
+
+The *KVM\_DEV\_USER\_PA\_RANGE* command configures a guest physical
+address range that the slave descriptor will receive MMIO notifications
+for. The range is specified by a guest physical range structure
+argument. For buses that assign addresses to devices dynamically, this
+command can be executed while the guest is running, such as the case
+when a guest changes a device's PCI BAR registers.
+
+*KVM\_DEV\_USER\_PA\_RANGE* will use ``kvm_io_bus_register_dev()`` to
+register *kvm\_io\_device\_ops* callbacks to be invoked when the guest
+performs a MMIO operation within the range. When a range is changed,
+``kvm_io_bus_unregister_dev()`` is used to remove the previous
+instantiation.
+
+*KVM\_DEV\_USER\_TIMEOUT* will configure a timeout value that specifies
+how long KVM will wait for the emulation process to respond to a MMIO
+indication.
+
+-  destroy
+
+This routine is called when the VM instance is destroyed. It will need
+to destroy the slave descriptor; and free any memory allocated by the
+driver, as well as the *kvm\_device* structure itself.
+
+slave descriptor
+^^^^^^^^^^^^^^^^
+
+The slave descriptor will have its own file operations vector, which
+responds to system calls on the descriptor performed by the device
+emulation program.
+
+-  read
+
+A read returns any pending MMIO requests from the KVM driver as MMIO
+request structures. Multiple structures can be returned if there are
+multiple MMIO operations pending. The MMIO requests are moved from the
+pending queue to the sent queue, and if there are threads waiting for
+space in the pending to add new MMIO operations, they will be woken
+here.
+
+-  write
+
+A write also consists of a set of MMIO requests. They are compared to
+the MMIO requests in the sent queue. Matches are removed from the sent
+queue, and any threads waiting for the reply are woken. If a store is
+removed, then the number of posted stores in the per-CPU scoreboard is
+decremented. When the number is zero, and a non side-effect load was
+waiting for posted stores to complete, the load is continued.
+
+-  ioctl
+
+There are several ioctl()s that can be performed on the slave
+descriptor.
+
+A *KVM\_DEV\_USER\_SHADOW\_SIZE* ``ioctl()`` causes the KVM driver to
+allocate memory for the shadow image. This memory can later be
+``mmap()``\ ed by the emulation process to share the emulation's view of
+device memory with the KVM driver.
+
+A *KVM\_DEV\_USER\_SHADOW\_CTRL* ``ioctl()`` controls access to the
+shadow image. It will send the KVM driver a shadow control map, which
+specifies which areas of the image can complete guest loads without
+sending the load request to the emulation program. It will also specify
+the size of load operations that are allowed.
+
+-  poll
+
+An emulation program will use the ``poll()`` call with a *POLLIN* flag
+to determine if there are MMIO requests waiting to be read. It will
+return if the pending MMIO request queue is not empty.
+
+-  mmap
+
+This call allows the emulation program to directly access the shadow
+image allocated by the KVM driver. As device emulation updates device
+memory, changes with no side-effects will be reflected in the shadow,
+and the KVM driver can satisfy guest loads from the shadow image without
+needing to wait for the emulation program.
+
+kvm\_io\_device ops
+^^^^^^^^^^^^^^^^^^^
+
+Each KVM per-CPU thread can handle MMIO operation on behalf of the guest
+VM. KVM will use the MMIO's guest physical address to search for a
+matching *kvm\_io\_device* to see if the MMIO can be handled by the KVM
+driver instead of exiting back to QEMU. If a match is found, the
+corresponding callback will be invoked.
+
+-  read
+
+This callback is invoked when the guest performs a load to the device.
+Loads with side-effects must be handled synchronously, with the KVM
+driver putting the QEMU thread to sleep waiting for the emulation
+process reply before re-starting the guest. Loads that do not have
+side-effects may be optimized by satisfying them from the shadow image,
+if there are no outstanding stores to the device by this CPU. PCI memory
+ordering demands that a load cannot complete before all older stores to
+the same device have been completed.
+
+-  write
+
+Stores can be handled asynchronously unless the pending MMIO request
+queue is full. In this case, the QEMU thread must sleep waiting for
+space in the queue. Stores will increment the number of posted stores in
+the per-CPU scoreboard, in order to implement the PCI ordering
+constraint above.
+
+interrupt acceleration
+^^^^^^^^^^^^^^^^^^^^^^
+
+This performance optimization would work much like a vhost user
+application does, where the QEMU process sets up *eventfds* that cause
+the device's corresponding interrupt to be triggered by the KVM driver.
+These irq file descriptors are sent to the emulation process at
+initialization, and are used when the emulation code raises a device
+interrupt.
+
+intx acceleration
+'''''''''''''''''
+
+Traditional PCI pin interrupts are level based, so, in addition to an
+irq file descriptor, a re-sampling file descriptor needs to be sent to
+the emulation program. This second file descriptor allows multiple
+devices sharing an irq to be notified when the interrupt has been
+acknowledged by the guest, so they can re-trigger the interrupt if their
+device has not de-asserted its interrupt.
+
+intx irq descriptor
+
+
+The irq descriptors are created by the proxy object
+``using event_notifier_init()`` to create the irq and re-sampling
+*eventds*, and ``kvm_vm_ioctl(KVM_IRQFD)`` to bind them to an interrupt.
+The interrupt route can be found with
+``pci_device_route_intx_to_irq()``.
+
+intx routing changes
+
+
+Intx routing can be changed when the guest programs the APIC the device
+pin is connected to. The proxy object in QEMU will use
+``pci_device_set_intx_routing_notifier()`` to be informed of any guest
+changes to the route. This handler will broadly follow the VFIO
+interrupt logic to change the route: de-assigning the existing irq
+descriptor from its route, then assigning it the new route. (see
+``vfio_intx_update()``)
+
+MSI/X acceleration
+''''''''''''''''''
+
+MSI/X interrupts are sent as DMA transactions to the host. The interrupt
+data contains a vector that is programmed by the guest, A device may have
+multiple MSI interrupts associated with it, so multiple irq descriptors
+may need to be sent to the emulation program.
+
+MSI/X irq descriptor
+
+
+This case will also follow the VFIO example. For each MSI/X interrupt,
+an *eventfd* is created, a virtual interrupt is allocated by
+``kvm_irqchip_add_msi_route()``, and the virtual interrupt is bound to
+the eventfd with ``kvm_irqchip_add_irqfd_notifier()``.
+
+MSI/X config space changes
+
+
+The guest may dynamically update several MSI-related tables in the
+device's PCI config space. These include per-MSI interrupt enables and
+vector data. Additionally, MSIX tables exist in device memory space, not
+config space. Much like the BAR case above, the proxy object must look
+at guest config space programming to keep the MSI interrupt state
+consistent between QEMU and the emulation program.
+
+--------------
+
+Disaggregated CPU emulation
+---------------------------
+
+After IO services have been disaggregated, a second phase would be to
+separate a process to handle CPU instruction emulation from the main
+QEMU control function. There are no object separation points for this
+code, so the first task would be to create one.
+
+Host access controls
+--------------------
+
+Separating QEMU relies on the host OS's access restriction mechanisms to
+enforce that the differing processes can only access the objects they
+are entitled to. There are a couple types of mechanisms usually provided
+by general purpose OSs.
+
+Discretionary access control
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Discretionary access control allows each user to control who can access
+their files. In Linux, this type of control is usually too coarse for
+QEMU separation, since it only provides three separate access controls:
+one for the same user ID, the second for users IDs with the same group
+ID, and the third for all other user IDs. Each device instance would
+need a separate user ID to provide access control, which is likely to be
+unwieldy for dynamically created VMs.
+
+Mandatory access control
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+Mandatory access control allows the OS to add an additional set of
+controls on top of discretionary access for the OS to control. It also
+adds other attributes to processes and files such as types, roles, and
+categories, and can establish rules for how processes and files can
+interact.
+
+Type enforcement
+^^^^^^^^^^^^^^^^
+
+Type enforcement assigns a *type* attribute to processes and files, and
+allows rules to be written on what operations a process with a given
+type can perform on a file with a given type. QEMU separation could take
+advantage of type enforcement by running the emulation processes with
+different types, both from the main QEMU process, and from the emulation
+processes of different classes of devices.
+
+For example, guest disk images and disk emulation processes could have
+types separate from the main QEMU process and non-disk emulation
+processes, and the type rules could prevent processes other than disk
+emulation ones from accessing guest disk images. Similarly, network
+emulation processes can have a type separate from the main QEMU process
+and non-network emulation process, and only that type can access the
+host tun/tap device used to provide guest networking.
+
+Category enforcement
+^^^^^^^^^^^^^^^^^^^^
+
+Category enforcement assigns a set of numbers within a given range to
+the process or file. The process is granted access to the file if the
+process's set is a superset of the file's set. This enforcement can be
+used to separate multiple instances of devices in the same class.
+
+For example, if there are multiple disk devices provides to a guest,
+each device emulation process could be provisioned with a separate
+category. The different device emulation processes would not be able to
+access each other's backing disk images.
+
+Alternatively, categories could be used in lieu of the type enforcement
+scheme described above. In this scenario, different categories would be
+used to prevent device emulation processes in different classes from
+accessing resources assigned to other classes.
-- 
2.29.2

From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

Adds documentation explaining the command-line arguments needed
to use multi-process.

[Move orphan docs/multi-process.rst document into docs/system/ and add
it to index.rst to prevent Sphinx "document isn't included in any
toctree" error.
--Stefan]

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 MAINTAINERS                   |  1 +
 docs/system/index.rst         |  1 +
 docs/system/multi-process.rst | 64 +++++++++++++++++++++++++++++++++++
 3 files changed, 66 insertions(+)
 create mode 100644 docs/system/multi-process.rst

diff --git a/MAINTAINERS b/MAINTAINERS
index XXXXXXX..XXXXXXX 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -XXX,XX +XXX,XX @@ M: Jagannathan Raman <jag.raman@oracle.com>
 M: John G Johnson <john.g.johnson@oracle.com>
 S: Maintained
 F: docs/devel/multi-process.rst
+F: docs/system/multi-process.rst
 
 Build and test automation
 -------------------------
diff --git a/docs/system/index.rst b/docs/system/index.rst
index XXXXXXX..XXXXXXX 100644
--- a/docs/system/index.rst
+++ b/docs/system/index.rst
@@ -XXX,XX +XXX,XX @@ Contents:
    pr-manager
    targets
    security
+   multi-process
    deprecated
    removed-features
    build-platforms
diff --git a/docs/system/multi-process.rst b/docs/system/multi-process.rst
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/docs/system/multi-process.rst
@@ -XXX,XX +XXX,XX @@
+Multi-process QEMU
+==================
+
+This document describes how to configure and use multi-process qemu.
+For the design document refer to docs/devel/qemu-multiprocess.
+
+1) Configuration
+----------------
+
+multi-process is enabled by default for targets that enable KVM
+
+
+2) Usage
+--------
+
+Multi-process QEMU requires an orchestrator to launch.
+
+Following is a description of command-line used to launch mpqemu.
+
+* Orchestrator:
+
+  - The Orchestrator creates a unix socketpair
+
+  - It launches the remote process and passes one of the
+    sockets to it via command-line.
+
+  - It then launches QEMU and specifies the other socket as an option
+    to the Proxy device object
+
+* Remote Process:
+
+  - QEMU can enter remote process mode by using the "remote" machine
+    option.
+
+  - The orchestrator creates a "remote-object" with details about
+    the device and the file descriptor for the device
+
+  - The remaining options are no different from how one launches QEMU with
+    devices.
+
+  - Example command-line for the remote process is as follows:
+
+      /usr/bin/qemu-system-x86_64                                        \
+      -machine x-remote                                                  \
+      -device lsi53c895a,id=lsi0                                         \
+      -drive id=drive_image2,file=/build/ol7-nvme-test-1.qcow2           \
+      -device scsi-hd,id=drive2,drive=drive_image2,bus=lsi0.0,scsi-id=0  \
+      -object x-remote-object,id=robj1,devid=lsi1,fd=4,
+
+* QEMU:
+
+  - Since parts of the RAM are shared between QEMU & remote process, a
+    memory-backend-memfd is required to facilitate this, as follows:
+
+    -object memory-backend-memfd,id=mem,size=2G
+
+  - A "x-pci-proxy-dev" device is created for each of the PCI devices emulated
+    in the remote process. A "socket" sub-option specifies the other end of
+    unix channel created by orchestrator. The "id" sub-option must be specified
+    and should be the same as the "id" specified for the remote PCI device
+
+  - Example commandline for QEMU is as follows:
+
+      -device x-pci-proxy-dev,id=lsi0,socket=3
-- 
2.29.2

From: Jagannathan Raman <jag.raman@oracle.com>

Allow RAM MemoryRegion to be created from an offset in a file, instead
of allocating at offset of 0 by default. This is needed to synchronize
RAM between QEMU & remote process.

Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 609996697ad8617e3b01df38accc5c208c24d74e.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 include/exec/memory.h     |  2 ++
 include/exec/ram_addr.h   |  4 ++--
 include/qemu/mmap-alloc.h |  4 +++-
 backends/hostmem-memfd.c  |  2 +-
 hw/misc/ivshmem.c         |  3 ++-
 softmmu/memory.c          |  3 ++-
 softmmu/physmem.c         | 12 +++++++-----
 util/mmap-alloc.c         |  8 +++++---
 util/oslib-posix.c        |  2 +-
 9 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/include/exec/memory.h b/include/exec/memory.h
index XXXXXXX..XXXXXXX 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -XXX,XX +XXX,XX @@ void memory_region_init_ram_from_file(MemoryRegion *mr,
  * @size: size of the region.
  * @share: %true if memory must be mmaped with the MAP_SHARED flag
  * @fd: the fd to mmap.
+ * @offset: offset within the file referenced by fd
  * @errp: pointer to Error*, to store an error if it happens.
  *
  * Note that this function does not do anything to cause the data in the
@@ -XXX,XX +XXX,XX @@ void memory_region_init_ram_from_fd(MemoryRegion *mr,
                                     uint64_t size,
                                     bool share,
                                     int fd,
+                                    ram_addr_t offset,
                                     Error **errp);
 #endif
 
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index XXXXXXX..XXXXXXX 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -XXX,XX +XXX,XX @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
                                    uint32_t ram_flags, const char *mem_path,
                                    bool readonly, Error **errp);
 RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
-                                 uint32_t ram_flags, int fd, bool readonly,
-                                 Error **errp);
+                                 uint32_t ram_flags, int fd, off_t offset,
+                                 bool readonly, Error **errp);
 
 RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
                                   MemoryRegion *mr, Error **errp);
diff --git a/include/qemu/mmap-alloc.h b/include/qemu/mmap-alloc.h
index XXXXXXX..XXXXXXX 100644
--- a/include/qemu/mmap-alloc.h
+++ b/include/qemu/mmap-alloc.h
@@ -XXX,XX +XXX,XX @@ size_t qemu_mempath_getpagesize(const char *mem_path);
  *  @readonly: true for a read-only mapping, false for read/write.
  *  @shared: map has RAM_SHARED flag.
  *  @is_pmem: map has RAM_PMEM flag.
+ *  @map_offset: map starts at offset of map_offset from the start of fd
  *
  * Return:
  *  On success, return a pointer to the mapped area.
@@ -XXX,XX +XXX,XX @@ void *qemu_ram_mmap(int fd,
                     size_t align,
                     bool readonly,
                     bool shared,
-                    bool is_pmem);
+                    bool is_pmem,
+                    off_t map_offset);
 
 void qemu_ram_munmap(int fd, void *ptr, size_t size);
 
diff --git a/backends/hostmem-memfd.c b/backends/hostmem-memfd.c
index XXXXXXX..XXXXXXX 100644
--- a/backends/hostmem-memfd.c
+++ b/backends/hostmem-memfd.c
@@ -XXX,XX +XXX,XX @@ memfd_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
     name = host_memory_backend_get_name(backend);
     memory_region_init_ram_from_fd(&backend->mr, OBJECT(backend),
                                    name, backend->size,
-                                   backend->share, fd, errp);
+                                   backend->share, fd, 0, errp);
     g_free(name);
 }
 
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -XXX,XX +XXX,XX @@ static void process_msg_shmem(IVShmemState *s, int fd, Error **errp)
 
     /* mmap the region and map into the BAR2 */
     memory_region_init_ram_from_fd(&s->server_bar2, OBJECT(s),
-                                   "ivshmem.bar2", size, true, fd, &local_err);
+                                   "ivshmem.bar2", size, true, fd, 0,
+                                   &local_err);
     if (local_err) {
         error_propagate(errp, local_err);
         return;
diff --git a/softmmu/memory.c b/softmmu/memory.c
index XXXXXXX..XXXXXXX 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -XXX,XX +XXX,XX @@ void memory_region_init_ram_from_fd(MemoryRegion *mr,
                                     uint64_t size,
                                     bool share,
                                     int fd,
+                                    ram_addr_t offset,
                                     Error **errp)
 {
     Error *err = NULL;
@@ -XXX,XX +XXX,XX @@ void memory_region_init_ram_from_fd(MemoryRegion *mr,
     mr->destructor = memory_region_destructor_ram;
     mr->ram_block = qemu_ram_alloc_from_fd(size, mr,
                                            share ? RAM_SHARED : 0,
-                                           fd, false, &err);
+                                           fd, offset, false, &err);
     if (err) {
         mr->size = int128_zero();
         object_unparent(OBJECT(mr));
diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index XXXXXXX..XXXXXXX 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -XXX,XX +XXX,XX @@ static void *file_ram_alloc(RAMBlock *block,
                             int fd,
                             bool readonly,
                             bool truncate,
+                            off_t offset,
                             Error **errp)
 {
     void *area;
@@ -XXX,XX +XXX,XX @@ static void *file_ram_alloc(RAMBlock *block,
     }
 
     area = qemu_ram_mmap(fd, memory, block->mr->align, readonly,
-                         block->flags & RAM_SHARED, block->flags & RAM_PMEM);
+                         block->flags & RAM_SHARED, block->flags & RAM_PMEM,
+                         offset);
     if (area == MAP_FAILED) {
         error_setg_errno(errp, errno,
                          "unable to map backing store for guest RAM");
@@ -XXX,XX +XXX,XX @@ static void ram_block_add(RAMBlock *new_block, Error **errp, bool shared)
 
 #ifdef CONFIG_POSIX
 RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
-                                 uint32_t ram_flags, int fd, bool readonly,
-                                 Error **errp)
+                                 uint32_t ram_flags, int fd, off_t offset,
+                                 bool readonly, Error **errp)
 {
     RAMBlock *new_block;
     Error *local_err = NULL;
@@ -XXX,XX +XXX,XX @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
     new_block->max_length = size;
     new_block->flags = ram_flags;
     new_block->host = file_ram_alloc(new_block, size, fd, readonly,
-                                     !file_size, errp);
+                                     !file_size, offset, errp);
     if (!new_block->host) {
         g_free(new_block);
         return NULL;
@@ -XXX,XX +XXX,XX @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
         return NULL;
     }
 
-    block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, readonly, errp);
+    block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, 0, readonly, errp);
     if (!block) {
         if (created) {
             unlink(mem_path);
diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
index XXXXXXX..XXXXXXX 100644
--- a/util/mmap-alloc.c
+++ b/util/mmap-alloc.c
@@ -XXX,XX +XXX,XX @@ void *qemu_ram_mmap(int fd,
                     size_t align,
                     bool readonly,
                     bool shared,
-                    bool is_pmem)
+                    bool is_pmem,
+                    off_t map_offset)
 {
     int prot;
     int flags;
@@ -XXX,XX +XXX,XX @@ void *qemu_ram_mmap(int fd,
 
     prot = PROT_READ | (readonly ? 0 : PROT_WRITE);
 
-    ptr = mmap(guardptr + offset, size, prot, flags | map_sync_flags, fd, 0);
+    ptr = mmap(guardptr + offset, size, prot,
+               flags | map_sync_flags, fd, map_offset);
 
     if (ptr == MAP_FAILED && map_sync_flags) {
         if (errno == ENOTSUP) {
@@ -XXX,XX +XXX,XX @@ void *qemu_ram_mmap(int fd,
          * if map failed with MAP_SHARED_VALIDATE | MAP_SYNC,
          * we will remove these flags to handle compatibility.
          */
-        ptr = mmap(guardptr + offset, size, prot, flags, fd, 0);
+        ptr = mmap(guardptr + offset, size, prot, flags, fd, map_offset);
     }
 
     if (ptr == MAP_FAILED) {
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index XXXXXXX..XXXXXXX 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -XXX,XX +XXX,XX @@ void *qemu_memalign(size_t alignment, size_t size)
 void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment, bool shared)
 {
     size_t align = QEMU_VMALLOC_ALIGN;
-    void *ptr = qemu_ram_mmap(-1, size, align, false, shared, false);
+    void *ptr = qemu_ram_mmap(-1, size, align, false, shared, false, 0);
 
     if (ptr == MAP_FAILED) {
         return NULL;
-- 
2.29.2

From: Jagannathan Raman <jag.raman@oracle.com>

Add configuration options to enable or disable multiprocess QEMU code

diff --git a/configure b/configure
index XXXXXXX..XXXXXXX 100755
--- a/configure
+++ b/configure
@@ -XXX,XX +XXX,XX @@ skip_meson=no
 gettext="auto"
 fuse="auto"
 fuse_lseek="auto"
+multiprocess="no"
 
 malloc_trim="auto"
 
@@ -XXX,XX +XXX,XX @@ Linux)
   linux="yes"
   linux_user="yes"
   vhost_user=${default_feature:-yes}
+  multiprocess=${default_feature:-yes}
 ;;
 esac
 
@@ -XXX,XX +XXX,XX @@ for opt do
   ;;
   --disable-fuse-lseek) fuse_lseek="disabled"
   ;;
+  --enable-multiprocess) multiprocess="yes"
+  ;;
+  --disable-multiprocess) multiprocess="no"
+  ;;
   *)
       echo "ERROR: unknown option $opt"
       echo "Try '$0 --help' for more information"
@@ -XXX,XX +XXX,XX @@ disabled with --disable-FEATURE, default is enabled if available
   libdaxctl       libdaxctl support
   fuse            FUSE block device export
   fuse-lseek      SEEK_HOLE/SEEK_DATA support for FUSE exports
+  multiprocess    Multiprocess QEMU support
 
 NOTE: The object files are built at the place where configure is launched
 EOF
@@ -XXX,XX +XXX,XX @@ fi
 if test "$have_mlockall" = "yes" ; then
   echo "HAVE_MLOCKALL=y" >> $config_host_mak
 fi
+if test "$multiprocess" = "yes" ; then
+  echo "CONFIG_MULTIPROCESS_ALLOWED=y" >> $config_host_mak
+fi
 if test "$fuzzing" = "yes" ; then
   # If LIB_FUZZING_ENGINE is set, assume we are running on OSS-Fuzz, and the
   # needed CFLAGS have already been provided
diff --git a/meson.build b/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/meson.build
+++ b/meson.build
@@ -XXX,XX +XXX,XX @@ host_kconfig = \
   ('CONFIG_VHOST_KERNEL' in config_host ? ['CONFIG_VHOST_KERNEL=y'] : []) + \
   (have_virtfs ? ['CONFIG_VIRTFS=y'] : []) + \
   ('CONFIG_LINUX' in config_host ? ['CONFIG_LINUX=y'] : []) + \
-  ('CONFIG_PVRDMA' in config_host ? ['CONFIG_PVRDMA=y'] : [])
+  ('CONFIG_PVRDMA' in config_host ? ['CONFIG_PVRDMA=y'] : []) + \
+  ('CONFIG_MULTIPROCESS_ALLOWED' in config_host ? ['CONFIG_MULTIPROCESS_ALLOWED=y'] : [])
 
 ignored = [ 'TARGET_XML_FILES', 'TARGET_ABI_DIR', 'TARGET_ARCH' ]
 
@@ -XXX,XX +XXX,XX @@ summary_info += {'libpmem support':   config_host.has_key('CONFIG_LIBPMEM')}
 summary_info += {'libdaxctl support': config_host.has_key('CONFIG_LIBDAXCTL')}
 summary_info += {'libudev':           libudev.found()}
 summary_info += {'FUSE lseek':        fuse_lseek.found()}
+summary_info += {'Multiprocess QEMU': config_host.has_key('CONFIG_MULTIPROCESS_ALLOWED')}
 summary(summary_info, bool_yn: true, section: 'Dependencies')
 
 if not supported_cpus.contains(cpu)
diff --git a/Kconfig.host b/Kconfig.host
index XXXXXXX..XXXXXXX 100644
--- a/Kconfig.host
+++ b/Kconfig.host
@@ -XXX,XX +XXX,XX @@ config VIRTFS
 
 config PVRDMA
     bool
+
+config MULTIPROCESS_ALLOWED
+    bool
+    imply MULTIPROCESS
diff --git a/hw/Kconfig b/hw/Kconfig
index XXXXXXX..XXXXXXX 100644
--- a/hw/Kconfig
+++ b/hw/Kconfig
@@ -XXX,XX +XXX,XX @@ source pci-host/Kconfig
 source pcmcia/Kconfig
 source pci/Kconfig
 source rdma/Kconfig
+source remote/Kconfig
 source rtc/Kconfig
 source scsi/Kconfig
 source sd/Kconfig
diff --git a/hw/remote/Kconfig b/hw/remote/Kconfig
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/hw/remote/Kconfig
@@ -XXX,XX +XXX,XX @@
+config MULTIPROCESS
+    bool
+    depends on PCI && KVM
-- 
2.29.2

From: Jagannathan Raman <jag.raman@oracle.com>

PCI host bridge is setup for the remote device process. It is
implemented using remote-pcihost object. It is an extension of the PCI
host bridge setup by QEMU.
Remote-pcihost configures a PCI bus which could be used by the remote
PCI device to latch on to.

[Added PCI_EXPRESS condition in hw/remote/Kconfig since remote-pcihost
needs PCIe. This solves "make check" failure on s390x. Fix suggested by
Philippe Mathieu-Daudé <philmd@redhat.com> and Thomas Huth
<thuth@redhat.com>.
--Stefan]

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 MAINTAINERS                  |  2 +
 include/hw/pci-host/remote.h | 29 ++++++++++++++
 hw/pci-host/remote.c         | 75 ++++++++++++++++++++++++++++++++++++
 hw/pci-host/Kconfig          |  3 ++
 hw/pci-host/meson.build      |  1 +
 hw/remote/Kconfig            |  3 +-
 6 files changed, 112 insertions(+), 1 deletion(-)
 create mode 100644 include/hw/pci-host/remote.h
 create mode 100644 hw/pci-host/remote.c

diff --git a/MAINTAINERS b/MAINTAINERS
index XXXXXXX..XXXXXXX 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -XXX,XX +XXX,XX @@ M: John G Johnson <john.g.johnson@oracle.com>
 S: Maintained
 F: docs/devel/multi-process.rst
 F: docs/system/multi-process.rst
+F: hw/pci-host/remote.c
+F: include/hw/pci-host/remote.h
 
 Build and test automation
 -------------------------
diff --git a/include/hw/pci-host/remote.h b/include/hw/pci-host/remote.h
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/include/hw/pci-host/remote.h
@@ -XXX,XX +XXX,XX @@
+/*
+ * PCI Host for remote device
+ *
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef REMOTE_PCIHOST_H
+#define REMOTE_PCIHOST_H
+
+#include "exec/memory.h"
+#include "hw/pci/pcie_host.h"
+
+#define TYPE_REMOTE_PCIHOST "remote-pcihost"
+OBJECT_DECLARE_SIMPLE_TYPE(RemotePCIHost, REMOTE_PCIHOST)
+
+struct RemotePCIHost {
+    /*< private >*/
+    PCIExpressHost parent_obj;
+    /*< public >*/
+
+    MemoryRegion *mr_pci_mem;
+    MemoryRegion *mr_sys_io;
+};
+
+#endif
diff --git a/hw/pci-host/remote.c b/hw/pci-host/remote.c
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/hw/pci-host/remote.c
@@ -XXX,XX +XXX,XX @@
+/*
+ * Remote PCI host device
+ *
+ * Unlike PCI host devices that model physical hardware, the purpose
+ * of this PCI host is to host multi-process QEMU devices.
+ *
+ * Multi-process QEMU extends the PCI host of a QEMU machine into a
+ * remote process. Any PCI device attached to the remote process is
+ * visible in the QEMU guest. This allows existing QEMU device models
+ * to be reused in the remote process.
+ *
+ * This PCI host is purely a container for PCI devices. It's fake in the
+ * sense that the guest never sees this PCI host and has no way of
+ * accessing it. Its job is just to provide the environment that QEMU
+ * PCI device models need when running in a remote process.
+ *
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+
+#include "hw/pci/pci.h"
+#include "hw/pci/pci_host.h"
+#include "hw/pci/pcie_host.h"
+#include "hw/qdev-properties.h"
+#include "hw/pci-host/remote.h"
+#include "exec/memory.h"
+
+static const char *remote_pcihost_root_bus_path(PCIHostState *host_bridge,
+                                                PCIBus *rootbus)
+{
+    return "0000:00";
+}
+
+static void remote_pcihost_realize(DeviceState *dev, Error **errp)
+{
+    PCIHostState *pci = PCI_HOST_BRIDGE(dev);
+    RemotePCIHost *s = REMOTE_PCIHOST(dev);
+
+    pci->bus = pci_root_bus_new(DEVICE(s), "remote-pci",
+                                s->mr_pci_mem, s->mr_sys_io,
+                                0, TYPE_PCIE_BUS);
+}
+
+static void remote_pcihost_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(klass);
+
+    hc->root_bus_path = remote_pcihost_root_bus_path;
+    dc->realize = remote_pcihost_realize;
+
+    dc->user_creatable = false;
+    set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
+    dc->fw_name = "pci";
+}
+
+static const TypeInfo remote_pcihost_info = {
+    .name = TYPE_REMOTE_PCIHOST,
+    .parent = TYPE_PCIE_HOST_BRIDGE,
+    .instance_size = sizeof(RemotePCIHost),
+    .class_init = remote_pcihost_class_init,
+};
+
+static void remote_pcihost_register(void)
+{
+    type_register_static(&remote_pcihost_info);
+}
+
+type_init(remote_pcihost_register)
diff --git a/hw/pci-host/Kconfig b/hw/pci-host/Kconfig
index XXXXXXX..XXXXXXX 100644
--- a/hw/pci-host/Kconfig
+++ b/hw/pci-host/Kconfig
@@ -XXX,XX +XXX,XX @@ config PCI_POWERNV
     select PCI_EXPRESS
     select MSI_NONBROKEN
     select PCIE_PORT
+
+config REMOTE_PCIHOST
+    bool
diff --git a/hw/pci-host/meson.build b/hw/pci-host/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/hw/pci-host/meson.build
+++ b/hw/pci-host/meson.build
@@ -XXX,XX +XXX,XX @@ pci_ss.add(when: 'CONFIG_PCI_EXPRESS_XILINX', if_true: files('xilinx-pcie.c'))
 pci_ss.add(when: 'CONFIG_PCI_I440FX', if_true: files('i440fx.c'))
 pci_ss.add(when: 'CONFIG_PCI_SABRE', if_true: files('sabre.c'))
 pci_ss.add(when: 'CONFIG_XEN_IGD_PASSTHROUGH', if_true: files('xen_igd_pt.c'))
+pci_ss.add(when: 'CONFIG_REMOTE_PCIHOST', if_true: files('remote.c'))
 
 # PPC devices
 pci_ss.add(when: 'CONFIG_PREP_PCI', if_true: files('prep.c'))
diff --git a/hw/remote/Kconfig b/hw/remote/Kconfig
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/Kconfig
+++ b/hw/remote/Kconfig
@@ -XXX,XX +XXX,XX @@
 config MULTIPROCESS
     bool
-    depends on PCI && KVM
+    depends on PCI && PCI_EXPRESS && KVM
+    select REMOTE_PCIHOST
-- 
2.29.2

From: Jagannathan Raman <jag.raman@oracle.com>

x-remote-machine object sets up various subsystems of the remote
device process. Instantiate PCI host bridge object and initialize RAM, IO &
PCI memory regions.

Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: c537f38d17f90453ca610c6b70cf3480274e0ba1.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 MAINTAINERS                  |  2 ++
 include/hw/pci-host/remote.h |  1 +
 include/hw/remote/machine.h  | 27 ++++++++++++++
 hw/remote/machine.c          | 70 ++++++++++++++++++++++++++++++++++++
 hw/meson.build               |  1 +
 hw/remote/meson.build        |  5 +++
 6 files changed, 106 insertions(+)
 create mode 100644 include/hw/remote/machine.h
 create mode 100644 hw/remote/machine.c
 create mode 100644 hw/remote/meson.build

diff --git a/MAINTAINERS b/MAINTAINERS
index XXXXXXX..XXXXXXX 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -XXX,XX +XXX,XX @@ F: docs/devel/multi-process.rst
 F: docs/system/multi-process.rst
 F: hw/pci-host/remote.c
 F: include/hw/pci-host/remote.h
+F: hw/remote/machine.c
+F: include/hw/remote/machine.h
 
 Build and test automation
 -------------------------
diff --git a/include/hw/pci-host/remote.h b/include/hw/pci-host/remote.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/pci-host/remote.h
+++ b/include/hw/pci-host/remote.h
@@ -XXX,XX +XXX,XX @@ struct RemotePCIHost {
 
     MemoryRegion *mr_pci_mem;
     MemoryRegion *mr_sys_io;
+    MemoryRegion *mr_sys_mem;
 };
 
 #endif
diff --git a/include/hw/remote/machine.h b/include/hw/remote/machine.h
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/include/hw/remote/machine.h
@@ -XXX,XX +XXX,XX @@
+/*
+ * Remote machine configuration
+ *
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef REMOTE_MACHINE_H
+#define REMOTE_MACHINE_H
+
+#include "qom/object.h"
+#include "hw/boards.h"
+#include "hw/pci-host/remote.h"
+
+struct RemoteMachineState {
+    MachineState parent_obj;
+
+    RemotePCIHost *host;
+};
+
+#define TYPE_REMOTE_MACHINE "x-remote-machine"
+OBJECT_DECLARE_SIMPLE_TYPE(RemoteMachineState, REMOTE_MACHINE)
+
+#endif
diff --git a/hw/remote/machine.c b/hw/remote/machine.c
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/hw/remote/machine.c
@@ -XXX,XX +XXX,XX @@
+/*
+ * Machine for remote device
+ *
+ *  This machine type is used by the remote device process in multi-process
+ *  QEMU. QEMU device models depend on parent busses, interrupt controllers,
+ *  memory regions, etc. The remote machine type offers this environment so
+ *  that QEMU device models can be used as remote devices.
+ *
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+
+#include "hw/remote/machine.h"
+#include "exec/address-spaces.h"
+#include "exec/memory.h"
+#include "qapi/error.h"
+
+static void remote_machine_init(MachineState *machine)
+{
+    MemoryRegion *system_memory, *system_io, *pci_memory;
+    RemoteMachineState *s = REMOTE_MACHINE(machine);
+    RemotePCIHost *rem_host;
+
+    system_memory = get_system_memory();
+    system_io = get_system_io();
+
+    pci_memory = g_new(MemoryRegion, 1);
+    memory_region_init(pci_memory, NULL, "pci", UINT64_MAX);
+
+    rem_host = REMOTE_PCIHOST(qdev_new(TYPE_REMOTE_PCIHOST));
+
+    rem_host->mr_pci_mem = pci_memory;
+    rem_host->mr_sys_mem = system_memory;
+    rem_host->mr_sys_io = system_io;
+
+    s->host = rem_host;
+
+    object_property_add_child(OBJECT(s), "remote-pcihost", OBJECT(rem_host));
+    memory_region_add_subregion_overlap(system_memory, 0x0, pci_memory, -1);
+
+    qdev_realize(DEVICE(rem_host), sysbus_get_default(), &error_fatal);
+}
+
+static void remote_machine_class_init(ObjectClass *oc, void *data)
+{
+    MachineClass *mc = MACHINE_CLASS(oc);
+
+    mc->init = remote_machine_init;
+    mc->desc = "Experimental remote machine";
+}
+
+static const TypeInfo remote_machine = {
+    .name = TYPE_REMOTE_MACHINE,
+    .parent = TYPE_MACHINE,
+    .instance_size = sizeof(RemoteMachineState),
+    .class_init = remote_machine_class_init,
+};
+
+static void remote_machine_register_types(void)
+{
+    type_register_static(&remote_machine);
+}
+
+type_init(remote_machine_register_types);
diff --git a/hw/meson.build b/hw/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/hw/meson.build
+++ b/hw/meson.build
@@ -XXX,XX +XXX,XX @@ subdir('moxie')
 subdir('nios2')
 subdir('openrisc')
 subdir('ppc')
+subdir('remote')
 subdir('riscv')
 subdir('rx')
 subdir('s390x')
diff --git a/hw/remote/meson.build b/hw/remote/meson.build
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/hw/remote/meson.build
@@ -XXX,XX +XXX,XX @@
+remote_ss = ss.source_set()
+
+remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('machine.c'))
+
+softmmu_ss.add_all(when: 'CONFIG_MULTIPROCESS', if_true: remote_ss)
-- 
2.29.2

From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

Adds qio_channel_writev_full_all() to transmit both data and FDs.
Refactors existing code to use this helper.

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 480fbf1fe4152495d60596c9b665124549b426a5.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 include/io/channel.h | 25 +++++++++++++++++++++++++
 io/channel.c         | 15 ++++++++++++++-
 2 files changed, 39 insertions(+), 1 deletion(-)

From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

Adds qio_channel_readv_full_all_eof() and qio_channel_readv_full_all()
to read both data and FDs. Refactors existing code to use these helpers.

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Acked-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: b059c4cc0fb741e794d644c144cc21372cad877d.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 include/io/channel.h |  53 +++++++++++++++++++++++
 io/channel.c         | 101 ++++++++++++++++++++++++++++++++++---------
 2 files changed, 134 insertions(+), 20 deletions(-)

diff --git a/include/io/channel.h b/include/io/channel.h
index XXXXXXX..XXXXXXX 100644
--- a/include/io/channel.h
+++ b/include/io/channel.h
@@ -XXX,XX +XXX,XX @@ void qio_channel_set_aio_fd_handler(QIOChannel *ioc,
                                     IOHandler *io_write,
                                     void *opaque);
 
+/**
+ * qio_channel_readv_full_all_eof:
+ * @ioc: the channel object
+ * @iov: the array of memory regions to read data to
+ * @niov: the length of the @iov array
+ * @fds: an array of file handles to read
+ * @nfds: number of file handles in @fds
+ * @errp: pointer to a NULL-initialized error object
+ *
+ *
+ * Performs same function as qio_channel_readv_all_eof.
+ * Additionally, attempts to read file descriptors shared
+ * over the channel. The function will wait for all
+ * requested data to be read, yielding from the current
+ * coroutine if required. data refers to both file
+ * descriptors and the iovs.
+ *
+ * Returns: 1 if all bytes were read, 0 if end-of-file
+ *          occurs without data, or -1 on error
+ */
+
+int qio_channel_readv_full_all_eof(QIOChannel *ioc,
+                                   const struct iovec *iov,
+                                   size_t niov,
+                                   int **fds, size_t *nfds,
+                                   Error **errp);
+
+/**
+ * qio_channel_readv_full_all:
+ * @ioc: the channel object
+ * @iov: the array of memory regions to read data to
+ * @niov: the length of the @iov array
+ * @fds: an array of file handles to read
+ * @nfds: number of file handles in @fds
+ * @errp: pointer to a NULL-initialized error object
+ *
+ *
+ * Performs same function as qio_channel_readv_all_eof.
+ * Additionally, attempts to read file descriptors shared
+ * over the channel. The function will wait for all
+ * requested data to be read, yielding from the current
+ * coroutine if required. data refers to both file
+ * descriptors and the iovs.
+ *
+ * Returns: 0 if all bytes were read, or -1 on error
+ */
+
+int qio_channel_readv_full_all(QIOChannel *ioc,
+                               const struct iovec *iov,
+                               size_t niov,
+                               int **fds, size_t *nfds,
+                               Error **errp);
+
 /**
  * qio_channel_writev_full_all:
  * @ioc: the channel object
diff --git a/io/channel.c b/io/channel.c
index XXXXXXX..XXXXXXX 100644
--- a/io/channel.c
+++ b/io/channel.c
@@ -XXX,XX +XXX,XX @@ int qio_channel_readv_all_eof(QIOChannel *ioc,
                               const struct iovec *iov,
                               size_t niov,
                               Error **errp)
+{
+    return qio_channel_readv_full_all_eof(ioc, iov, niov, NULL, NULL, errp);
+}
+
+int qio_channel_readv_all(QIOChannel *ioc,
+                          const struct iovec *iov,
+                          size_t niov,
+                          Error **errp)
+{
+    return qio_channel_readv_full_all(ioc, iov, niov, NULL, NULL, errp);
+}
+
+int qio_channel_readv_full_all_eof(QIOChannel *ioc,
+                                   const struct iovec *iov,
+                                   size_t niov,
+                                   int **fds, size_t *nfds,
+                                   Error **errp)
 {
     int ret = -1;
     struct iovec *local_iov = g_new(struct iovec, niov);
     struct iovec *local_iov_head = local_iov;
     unsigned int nlocal_iov = niov;
+    int **local_fds = fds;
+    size_t *local_nfds = nfds;
     bool partial = false;
 
+    if (nfds) {
+        *nfds = 0;
+    }
+
+    if (fds) {
+        *fds = NULL;
+    }
+
     nlocal_iov = iov_copy(local_iov, nlocal_iov,
                           iov, niov,
                           0, iov_size(iov, niov));
 
-    while (nlocal_iov > 0) {
+    while ((nlocal_iov > 0) || local_fds) {
         ssize_t len;
-        len = qio_channel_readv(ioc, local_iov, nlocal_iov, errp);
+        len = qio_channel_readv_full(ioc, local_iov, nlocal_iov, local_fds,
+                                     local_nfds, errp);
         if (len == QIO_CHANNEL_ERR_BLOCK) {
             if (qemu_in_coroutine()) {
                 qio_channel_yield(ioc, G_IO_IN);
@@ -XXX,XX +XXX,XX @@ int qio_channel_readv_all_eof(QIOChannel *ioc,
                 qio_channel_wait(ioc, G_IO_IN);
             }
             continue;
-        } else if (len < 0) {
-            goto cleanup;
-        } else if (len == 0) {
-            if (partial) {
-                error_setg(errp,
-                           "Unexpected end-of-file before all bytes were read");
-            } else {
+        }
+
+        if (len == 0) {
+            if (local_nfds && *local_nfds) {
+                /*
+                 * Got some FDs, but no data yet. This isn't an EOF
+                 * scenario (yet), so carry on to try to read data
+                 * on next loop iteration
+                 */
+                goto next_iter;
+            } else if (!partial) {
+                /* No fds and no data - EOF before any data read */
                 ret = 0;
+                goto cleanup;
+            } else {
+                len = -1;
+                error_setg(errp,
+                           "Unexpected end-of-file before all data were read");
+                /* Fallthrough into len < 0 handling */
+            }
+        }
+
+        if (len < 0) {
+            /* Close any FDs we previously received */
+            if (nfds && fds) {
+                size_t i;
+                for (i = 0; i < (*nfds); i++) {
+                    close((*fds)[i]);
+                }
+                g_free(*fds);
+                *fds = NULL;
+                *nfds = 0;
             }
             goto cleanup;
         }
 
+        if (nlocal_iov) {
+            iov_discard_front(&local_iov, &nlocal_iov, len);
+        }
+
+next_iter:
         partial = true;
-        iov_discard_front(&local_iov, &nlocal_iov, len);
+        local_fds = NULL;
+        local_nfds = NULL;
     }
 
     ret = 1;
@@ -XXX,XX +XXX,XX @@ int qio_channel_readv_all_eof(QIOChannel *ioc,
     return ret;
 }
 
-int qio_channel_readv_all(QIOChannel *ioc,
-                          const struct iovec *iov,
-                          size_t niov,
-                          Error **errp)
+int qio_channel_readv_full_all(QIOChannel *ioc,
+                               const struct iovec *iov,
+                               size_t niov,
+                               int **fds, size_t *nfds,
+                               Error **errp)
 {
-    int ret = qio_channel_readv_all_eof(ioc, iov, niov, errp);
+    int ret = qio_channel_readv_full_all_eof(ioc, iov, niov, fds, nfds, errp);
 
     if (ret == 0) {
-        ret = -1;
-        error_setg(errp,
-                   "Unexpected end-of-file before all bytes were read");
-    } else if (ret == 1) {
-        ret = 0;
+        error_prepend(errp,
+                      "Unexpected end-of-file before all data were read.");
+        return -1;
     }
+    if (ret == 1) {
+        return 0;
+    }
+
     return ret;
 }
 
-- 
2.29.2

From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

Defines MPQemuMsg, which is the message that is sent to the remote
process. This message is sent over QIOChannel and is used to
command the remote process to perform various tasks.
Define transmission functions used by proxy and by remote.

[Replace struct iovec send[2] = {0} with {} to make clang happy as
suggested by Peter Maydell <peter.maydell@linaro.org>.
--Stefan]

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 MAINTAINERS                     |   2 +
 meson.build                     |   1 +
 hw/remote/trace.h               |   1 +
 include/hw/remote/mpqemu-link.h |  63 ++++++++++
 include/sysemu/iothread.h       |   6 +
 hw/remote/mpqemu-link.c         | 205 ++++++++++++++++++++++++++++++++
 iothread.c                      |   6 +
 hw/remote/meson.build           |   1 +
 hw/remote/trace-events          |   4 +
 9 files changed, 289 insertions(+)
 create mode 100644 hw/remote/trace.h
 create mode 100644 include/hw/remote/mpqemu-link.h
 create mode 100644 hw/remote/mpqemu-link.c
 create mode 100644 hw/remote/trace-events

diff --git a/MAINTAINERS b/MAINTAINERS
index XXXXXXX..XXXXXXX 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -XXX,XX +XXX,XX @@ F: hw/pci-host/remote.c
 F: include/hw/pci-host/remote.h
 F: hw/remote/machine.c
 F: include/hw/remote/machine.h
+F: hw/remote/mpqemu-link.c
+F: include/hw/remote/mpqemu-link.h
 
 Build and test automation
 -------------------------
diff --git a/meson.build b/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/meson.build
+++ b/meson.build
@@ -XXX,XX +XXX,XX @@ if have_system
     'net',
     'softmmu',
     'ui',
+    'hw/remote',
   ]
 endif
 if have_system or have_user
diff --git a/hw/remote/trace.h b/hw/remote/trace.h
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/hw/remote/trace.h
@@ -0,0 +1 @@
+#include "trace/trace-hw_remote.h"
diff --git a/include/hw/remote/mpqemu-link.h b/include/hw/remote/mpqemu-link.h
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/include/hw/remote/mpqemu-link.h
@@ -XXX,XX +XXX,XX @@
+/*
+ * Communication channel between QEMU and remote device process
+ *
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef MPQEMU_LINK_H
+#define MPQEMU_LINK_H
+
+#include "qom/object.h"
+#include "qemu/thread.h"
+#include "io/channel.h"
+
+#define REMOTE_MAX_FDS 8
+
+#define MPQEMU_MSG_HDR_SIZE offsetof(MPQemuMsg, data.u64)
+
+/**
+ * MPQemuCmd:
+ *
+ * MPQemuCmd enum type to specify the command to be executed on the remote
+ * device.
+ *
+ * This uses a private protocol between QEMU and the remote process. vfio-user
+ * protocol would supersede this in the future.
+ *
+ */
+typedef enum {
+    MPQEMU_CMD_MAX,
+} MPQemuCmd;
+
+/**
+ * MPQemuMsg:
+ * @cmd: The remote command
+ * @size: Size of the data to be shared
+ * @data: Structured data
+ * @fds: File descriptors to be shared with remote device
+ *
+ * MPQemuMsg Format of the message sent to the remote device from QEMU.
+ *
+ */
+typedef struct {
+    int cmd;
+    size_t size;
+
+    union {
+        uint64_t u64;
+    } data;
+
+    int fds[REMOTE_MAX_FDS];
+    int num_fds;
+} MPQemuMsg;
+
+bool mpqemu_msg_send(MPQemuMsg *msg, QIOChannel *ioc, Error **errp);
+bool mpqemu_msg_recv(MPQemuMsg *msg, QIOChannel *ioc, Error **errp);
+
+bool mpqemu_msg_valid(MPQemuMsg *msg);
+
+#endif
diff --git a/include/sysemu/iothread.h b/include/sysemu/iothread.h
index XXXXXXX..XXXXXXX 100644
--- a/include/sysemu/iothread.h
+++ b/include/sysemu/iothread.h
@@ -XXX,XX +XXX,XX @@ IOThread *iothread_create(const char *id, Error **errp);
 void iothread_stop(IOThread *iothread);
 void iothread_destroy(IOThread *iothread);
 
+/*
+ * Returns true if executing withing IOThread context,
+ * false otherwise.
+ */
+bool qemu_in_iothread(void);
+
 #endif /* IOTHREAD_H */
diff --git a/hw/remote/mpqemu-link.c b/hw/remote/mpqemu-link.c
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/hw/remote/mpqemu-link.c
@@ -XXX,XX +XXX,XX @@
+/*
+ * Communication channel between QEMU and remote device process
+ *
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+
+#include "qemu/module.h"
+#include "hw/remote/mpqemu-link.h"
+#include "qapi/error.h"
+#include "qemu/iov.h"
+#include "qemu/error-report.h"
+#include "qemu/main-loop.h"
+#include "io/channel.h"
+#include "sysemu/iothread.h"
+#include "trace.h"
+
+/*
+ * Send message over the ioc QIOChannel.
+ * This function is safe to call from:
+ * - main loop in co-routine context. Will block the main loop if not in
+ *   co-routine context;
+ * - vCPU thread with no co-routine context and if the channel is not part
+ *   of the main loop handling;
+ * - IOThread within co-routine context, outside of co-routine context
+ *   will block IOThread;
+ * Returns true if no errors were encountered, false otherwise.
+ */
+bool mpqemu_msg_send(MPQemuMsg *msg, QIOChannel *ioc, Error **errp)
+{
+    ERRP_GUARD();
+    bool iolock = qemu_mutex_iothread_locked();
+    bool iothread = qemu_in_iothread();
+    struct iovec send[2] = {};
+    int *fds = NULL;
+    size_t nfds = 0;
+    bool ret = false;
+
+    send[0].iov_base = msg;
+    send[0].iov_len = MPQEMU_MSG_HDR_SIZE;
+
+    send[1].iov_base = (void *)&msg->data;
+    send[1].iov_len = msg->size;
+
+    if (msg->num_fds) {
+        nfds = msg->num_fds;
+        fds = msg->fds;
+    }
+
+    /*
+     * Dont use in IOThread out of co-routine context as
+     * it will block IOThread.
+     */
+    assert(qemu_in_coroutine() || !iothread);
+
+    /*
+     * Skip unlocking/locking iothread lock when the IOThread is running
+     * in co-routine context. Co-routine context is asserted above
+     * for IOThread case.
+     * Also skip lock handling while in a co-routine in the main context.
+     */
+    if (iolock && !iothread && !qemu_in_coroutine()) {
+        qemu_mutex_unlock_iothread();
+    }
+
+    if (!qio_channel_writev_full_all(ioc, send, G_N_ELEMENTS(send),
+                                    fds, nfds, errp)) {
+        ret = true;
+    } else {
+        trace_mpqemu_send_io_error(msg->cmd, msg->size, nfds);
+    }
+
+    if (iolock && !iothread && !qemu_in_coroutine()) {
+        /* See above comment why skip locking here. */
+        qemu_mutex_lock_iothread();
+    }
+
+    return ret;
+}
+
+/*
+ * Read message from the ioc QIOChannel.
+ * This function is safe to call from:
+ * - From main loop in co-routine context. Will block the main loop if not in
+ *   co-routine context;
+ * - From vCPU thread with no co-routine context and if the channel is not part
+ *   of the main loop handling;
+ * - From IOThread within co-routine context, outside of co-routine context
+ *   will block IOThread;
+ */
+static ssize_t mpqemu_read(QIOChannel *ioc, void *buf, size_t len, int **fds,
+                           size_t *nfds, Error **errp)
+{
+    ERRP_GUARD();
+    struct iovec iov = { .iov_base = buf, .iov_len = len };
+    bool iolock = qemu_mutex_iothread_locked();
+    bool iothread = qemu_in_iothread();
+    int ret = -1;
+
+    /*
+     * Dont use in IOThread out of co-routine context as
+     * it will block IOThread.
+     */
+    assert(qemu_in_coroutine() || !iothread);
+
+    if (iolock && !iothread && !qemu_in_coroutine()) {
+        qemu_mutex_unlock_iothread();
+    }
+
+    ret = qio_channel_readv_full_all_eof(ioc, &iov, 1, fds, nfds, errp);
+
+    if (iolock && !iothread && !qemu_in_coroutine()) {
+        qemu_mutex_lock_iothread();
+    }
+
+    return (ret <= 0) ? ret : iov.iov_len;
+}
+
+bool mpqemu_msg_recv(MPQemuMsg *msg, QIOChannel *ioc, Error **errp)
+{
+    ERRP_GUARD();
+    g_autofree int *fds = NULL;
+    size_t nfds = 0;
+    ssize_t len;
+    bool ret = false;
+
+    len = mpqemu_read(ioc, msg, MPQEMU_MSG_HDR_SIZE, &fds, &nfds, errp);
+    if (len <= 0) {
+        goto fail;
+    } else if (len != MPQEMU_MSG_HDR_SIZE) {
+        error_setg(errp, "Message header corrupted");
+        goto fail;
+    }
+
+    if (msg->size > sizeof(msg->data)) {
+        error_setg(errp, "Invalid size for message");
+        goto fail;
+    }
+
+    if (!msg->size) {
+        goto copy_fds;
+    }
+
+    len = mpqemu_read(ioc, &msg->data, msg->size, NULL, NULL, errp);
+    if (len <= 0) {
+        goto fail;
+    }
+    if (len != msg->size) {
+        error_setg(errp, "Unable to read full message");
+        goto fail;
+    }
+
+copy_fds:
+    msg->num_fds = nfds;
+    if (nfds > G_N_ELEMENTS(msg->fds)) {
+        error_setg(errp,
+                   "Overflow error: received %zu fds, more than max of %d fds",
+                   nfds, REMOTE_MAX_FDS);
+        goto fail;
+    }
+    if (nfds) {
+        memcpy(msg->fds, fds, nfds * sizeof(int));
+    }
+
+    ret = true;
+
+fail:
+    if (*errp) {
+        trace_mpqemu_recv_io_error(msg->cmd, msg->size, nfds);
+    }
+    while (*errp && nfds) {
+        close(fds[nfds - 1]);
+        nfds--;
+    }
+
+    return ret;
+}
+
+bool mpqemu_msg_valid(MPQemuMsg *msg)
+{
+    if (msg->cmd >= MPQEMU_CMD_MAX && msg->cmd < 0) {
+        return false;
+    }
+
+    /* Verify FDs. */
+    if (msg->num_fds >= REMOTE_MAX_FDS) {
+        return false;
+    }
+
+    if (msg->num_fds > 0) {
+        for (int i = 0; i < msg->num_fds; i++) {
+            if (fcntl(msg->fds[i], F_GETFL) == -1) {
+                return false;
+            }
+        }
+    }
+
+    return true;
+}
diff --git a/iothread.c b/iothread.c
index XXXXXXX..XXXXXXX 100644
--- a/iothread.c
+++ b/iothread.c
@@ -XXX,XX +XXX,XX @@ IOThread *iothread_by_id(const char *id)
 {
     return IOTHREAD(object_resolve_path_type(id, TYPE_IOTHREAD, NULL));
 }
+
+bool qemu_in_iothread(void)
+{
+    return qemu_get_current_aio_context() == qemu_get_aio_context() ?
+                    false : true;
+}
diff --git a/hw/remote/meson.build b/hw/remote/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/meson.build
+++ b/hw/remote/meson.build
@@ -XXX,XX +XXX,XX @@
 remote_ss = ss.source_set()
 
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('machine.c'))
+remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('mpqemu-link.c'))
 
 softmmu_ss.add_all(when: 'CONFIG_MULTIPROCESS', if_true: remote_ss)
diff --git a/hw/remote/trace-events b/hw/remote/trace-events
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/hw/remote/trace-events
@@ -XXX,XX +XXX,XX @@
+# multi-process trace events
+
+mpqemu_send_io_error(int cmd, int size, int nfds) "send command %d size %d, %d file descriptors to remote process"
+mpqemu_recv_io_error(int cmd, int size, int nfds) "failed to receive %d size %d, %d file descriptors to remote process"
-- 
2.29.2

From: Jagannathan Raman <jag.raman@oracle.com>

Initializes the message handler function in the remote process. It is
called whenever there's an event pending on QIOChannel that registers
this function.

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 99d38d8b93753a6409ac2340e858858cda59ab1b.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 MAINTAINERS                 |  1 +
 include/hw/remote/machine.h |  9 ++++++
 hw/remote/message.c         | 57 +++++++++++++++++++++++++++++++++++++
 hw/remote/meson.build       |  1 +
 4 files changed, 68 insertions(+)
 create mode 100644 hw/remote/message.c

diff --git a/MAINTAINERS b/MAINTAINERS
index XXXXXXX..XXXXXXX 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -XXX,XX +XXX,XX @@ F: hw/remote/machine.c
 F: include/hw/remote/machine.h
 F: hw/remote/mpqemu-link.c
 F: include/hw/remote/mpqemu-link.h
+F: hw/remote/message.c
 
 Build and test automation
 -------------------------
diff --git a/include/hw/remote/machine.h b/include/hw/remote/machine.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/remote/machine.h
+++ b/include/hw/remote/machine.h
@@ -XXX,XX +XXX,XX @@
 #include "qom/object.h"
 #include "hw/boards.h"
 #include "hw/pci-host/remote.h"
+#include "io/channel.h"
 
 struct RemoteMachineState {
     MachineState parent_obj;
@@ -XXX,XX +XXX,XX @@ struct RemoteMachineState {
     RemotePCIHost *host;
 };
 
+/* Used to pass to co-routine device and ioc. */
+typedef struct RemoteCommDev {
+    PCIDevice *dev;
+    QIOChannel *ioc;
+} RemoteCommDev;
+
 #define TYPE_REMOTE_MACHINE "x-remote-machine"
 OBJECT_DECLARE_SIMPLE_TYPE(RemoteMachineState, REMOTE_MACHINE)
 
+void coroutine_fn mpqemu_remote_msg_loop_co(void *data);
+
 #endif
diff --git a/hw/remote/message.c b/hw/remote/message.c
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/hw/remote/message.c
@@ -XXX,XX +XXX,XX @@
+/*
+ * Copyright © 2020, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL-v2, version 2 or later.
+ *
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+
+#include "hw/remote/machine.h"
+#include "io/channel.h"
+#include "hw/remote/mpqemu-link.h"
+#include "qapi/error.h"
+#include "sysemu/runstate.h"
+
+void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
+{
+    g_autofree RemoteCommDev *com = (RemoteCommDev *)data;
+    PCIDevice *pci_dev = NULL;
+    Error *local_err = NULL;
+
+    assert(com->ioc);
+
+    pci_dev = com->dev;
+    for (; !local_err;) {
+        MPQemuMsg msg = {0};
+
+        if (!mpqemu_msg_recv(&msg, com->ioc, &local_err)) {
+            break;
+        }
+
+        if (!mpqemu_msg_valid(&msg)) {
+            error_setg(&local_err, "Received invalid message from proxy"
+                                   "in remote process pid="FMT_pid"",
+                                   getpid());
+            break;
+        }
+
+        switch (msg.cmd) {
+        default:
+            error_setg(&local_err,
+                       "Unknown command (%d) received for device %s"
+                       " (pid="FMT_pid")",
+                       msg.cmd, DEVICE(pci_dev)->id, getpid());
+        }
+    }
+
+    if (local_err) {
+        error_report_err(local_err);
+        qemu_system_shutdown_request(SHUTDOWN_CAUSE_HOST_ERROR);
+    } else {
+        qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
+    }
+}
diff --git a/hw/remote/meson.build b/hw/remote/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/meson.build
+++ b/hw/remote/meson.build
@@ -XXX,XX +XXX,XX @@ remote_ss = ss.source_set()
 
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('machine.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('mpqemu-link.c'))
+remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('message.c'))
 
 softmmu_ss.add_all(when: 'CONFIG_MULTIPROCESS', if_true: remote_ss)
-- 
2.29.2

From: Jagannathan Raman <jag.raman@oracle.com>

Associate the file descriptor for a PCIDevice in remote process with
DeviceState object.

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: f405a2ed5d7518b87bea7c59cfdf334d67e5ee51.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 MAINTAINERS            |   1 +
 hw/remote/remote-obj.c | 203 +++++++++++++++++++++++++++++++++++++++++
 hw/remote/meson.build  |   1 +
 3 files changed, 205 insertions(+)
 create mode 100644 hw/remote/remote-obj.c

diff --git a/MAINTAINERS b/MAINTAINERS
index XXXXXXX..XXXXXXX 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -XXX,XX +XXX,XX @@ F: include/hw/remote/machine.h
 F: hw/remote/mpqemu-link.c
 F: include/hw/remote/mpqemu-link.h
 F: hw/remote/message.c
+F: hw/remote/remote-obj.c
 
 Build and test automation
 -------------------------
diff --git a/hw/remote/remote-obj.c b/hw/remote/remote-obj.c
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/hw/remote/remote-obj.c
@@ -XXX,XX +XXX,XX @@
+/*
+ * Copyright © 2020, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL-v2, version 2 or later.
+ *
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+
+#include "qemu/error-report.h"
+#include "qemu/notify.h"
+#include "qom/object_interfaces.h"
+#include "hw/qdev-core.h"
+#include "io/channel.h"
+#include "hw/qdev-core.h"
+#include "hw/remote/machine.h"
+#include "io/channel-util.h"
+#include "qapi/error.h"
+#include "sysemu/sysemu.h"
+#include "hw/pci/pci.h"
+#include "qemu/sockets.h"
+#include "monitor/monitor.h"
+
+#define TYPE_REMOTE_OBJECT "x-remote-object"
+OBJECT_DECLARE_TYPE(RemoteObject, RemoteObjectClass, REMOTE_OBJECT)
+
+struct RemoteObjectClass {
+    ObjectClass parent_class;
+
+    unsigned int nr_devs;
+    unsigned int max_devs;
+};
+
+struct RemoteObject {
+    /* private */
+    Object parent;
+
+    Notifier machine_done;
+
+    int32_t fd;
+    char *devid;
+
+    QIOChannel *ioc;
+
+    DeviceState *dev;
+    DeviceListener listener;
+};
+
+static void remote_object_set_fd(Object *obj, const char *str, Error **errp)
+{
+    RemoteObject *o = REMOTE_OBJECT(obj);
+    int fd = -1;
+
+    fd = monitor_fd_param(monitor_cur(), str, errp);
+    if (fd == -1) {
+        error_prepend(errp, "Could not parse remote object fd %s:", str);
+        return;
+    }
+
+    if (!fd_is_socket(fd)) {
+        error_setg(errp, "File descriptor '%s' is not a socket", str);
+        close(fd);
+        return;
+    }
+
+    o->fd = fd;
+}
+
+static void remote_object_set_devid(Object *obj, const char *str, Error **errp)
+{
+    RemoteObject *o = REMOTE_OBJECT(obj);
+
+    g_free(o->devid);
+
+    o->devid = g_strdup(str);
+}
+
+static void remote_object_unrealize_listener(DeviceListener *listener,
+                                             DeviceState *dev)
+{
+    RemoteObject *o = container_of(listener, RemoteObject, listener);
+
+    if (o->dev == dev) {
+        object_unref(OBJECT(o));
+    }
+}
+
+static void remote_object_machine_done(Notifier *notifier, void *data)
+{
+    RemoteObject *o = container_of(notifier, RemoteObject, machine_done);
+    DeviceState *dev = NULL;
+    QIOChannel *ioc = NULL;
+    Coroutine *co = NULL;
+    RemoteCommDev *comdev = NULL;
+    Error *err = NULL;
+
+    dev = qdev_find_recursive(sysbus_get_default(), o->devid);
+    if (!dev || !object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
+        error_report("%s is not a PCI device", o->devid);
+        return;
+    }
+
+    ioc = qio_channel_new_fd(o->fd, &err);
+    if (!ioc) {
+        error_report_err(err);
+        return;
+    }
+    qio_channel_set_blocking(ioc, false, NULL);
+
+    o->dev = dev;
+
+    o->listener.unrealize = remote_object_unrealize_listener;
+    device_listener_register(&o->listener);
+
+    /* co-routine should free this. */
+    comdev = g_new0(RemoteCommDev, 1);
+    *comdev = (RemoteCommDev) {
+        .ioc = ioc,
+        .dev = PCI_DEVICE(dev),
+    };
+
+    co = qemu_coroutine_create(mpqemu_remote_msg_loop_co, comdev);
+    qemu_coroutine_enter(co);
+}
+
+static void remote_object_init(Object *obj)
+{
+    RemoteObjectClass *k = REMOTE_OBJECT_GET_CLASS(obj);
+    RemoteObject *o = REMOTE_OBJECT(obj);
+
+    if (k->nr_devs >= k->max_devs) {
+        error_report("Reached maximum number of devices: %u", k->max_devs);
+        return;
+    }
+
+    o->ioc = NULL;
+    o->fd = -1;
+    o->devid = NULL;
+
+    k->nr_devs++;
+
+    o->machine_done.notify = remote_object_machine_done;
+    qemu_add_machine_init_done_notifier(&o->machine_done);
+}
+
+static void remote_object_finalize(Object *obj)
+{
+    RemoteObjectClass *k = REMOTE_OBJECT_GET_CLASS(obj);
+    RemoteObject *o = REMOTE_OBJECT(obj);
+
+    device_listener_unregister(&o->listener);
+
+    if (o->ioc) {
+        qio_channel_shutdown(o->ioc, QIO_CHANNEL_SHUTDOWN_BOTH, NULL);
+        qio_channel_close(o->ioc, NULL);
+    }
+
+    object_unref(OBJECT(o->ioc));
+
+    k->nr_devs--;
+    g_free(o->devid);
+}
+
+static void remote_object_class_init(ObjectClass *klass, void *data)
+{
+    RemoteObjectClass *k = REMOTE_OBJECT_CLASS(klass);
+
+    /*
+     * Limit number of supported devices to 1. This is done to avoid devices
+     * from one VM accessing the RAM of another VM. This is done until we
+     * start using separate address spaces for individual devices.
+     */
+    k->max_devs = 1;
+    k->nr_devs = 0;
+
+    object_class_property_add_str(klass, "fd", NULL, remote_object_set_fd);
+    object_class_property_add_str(klass, "devid", NULL,
+                                  remote_object_set_devid);
+}
+
+static const TypeInfo remote_object_info = {
+    .name = TYPE_REMOTE_OBJECT,
+    .parent = TYPE_OBJECT,
+    .instance_size = sizeof(RemoteObject),
+    .instance_init = remote_object_init,
+    .instance_finalize = remote_object_finalize,
+    .class_size = sizeof(RemoteObjectClass),
+    .class_init = remote_object_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_USER_CREATABLE },
+        { }
+    }
+};
+
+static void register_types(void)
+{
+    type_register_static(&remote_object_info);
+}
+
+type_init(register_types);
diff --git a/hw/remote/meson.build b/hw/remote/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/meson.build
+++ b/hw/remote/meson.build
@@ -XXX,XX +XXX,XX @@ remote_ss = ss.source_set()
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('machine.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('mpqemu-link.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('message.c'))
+remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('remote-obj.c'))
 
 softmmu_ss.add_all(when: 'CONFIG_MULTIPROCESS', if_true: remote_ss)
-- 
2.29.2

From: Jagannathan Raman <jag.raman@oracle.com>

SyncSysMemMsg message format is defined. It is used to send
file descriptors of the RAM regions to remote device.
RAM on the remote device is configured with a set of file descriptors.
Old RAM regions are deleted and new regions, each with an fd, is
added to the RAM.

Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 7d2d1831d812e85f681e7a8ab99e032cf4704689.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 MAINTAINERS                     |  2 +
 include/hw/remote/memory.h      | 19 ++++++++++
 include/hw/remote/mpqemu-link.h | 10 +++++
 hw/remote/memory.c              | 65 +++++++++++++++++++++++++++++++++
 hw/remote/mpqemu-link.c         | 11 ++++++
 hw/remote/meson.build           |  2 +
 6 files changed, 109 insertions(+)
 create mode 100644 include/hw/remote/memory.h
 create mode 100644 hw/remote/memory.c

diff --git a/MAINTAINERS b/MAINTAINERS
index XXXXXXX..XXXXXXX 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -XXX,XX +XXX,XX @@ F: hw/remote/mpqemu-link.c
 F: include/hw/remote/mpqemu-link.h
 F: hw/remote/message.c
 F: hw/remote/remote-obj.c
+F: include/hw/remote/memory.h
+F: hw/remote/memory.c
 
 Build and test automation
 -------------------------
diff --git a/include/hw/remote/memory.h b/include/hw/remote/memory.h
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/include/hw/remote/memory.h
@@ -XXX,XX +XXX,XX @@
+/*
+ * Memory manager for remote device
+ *
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef REMOTE_MEMORY_H
+#define REMOTE_MEMORY_H
+
+#include "exec/hwaddr.h"
+#include "hw/remote/mpqemu-link.h"
+
+void remote_sysmem_reconfig(MPQemuMsg *msg, Error **errp);
+
+#endif
diff --git a/include/hw/remote/mpqemu-link.h b/include/hw/remote/mpqemu-link.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/remote/mpqemu-link.h
+++ b/include/hw/remote/mpqemu-link.h
@@ -XXX,XX +XXX,XX @@
 #include "qom/object.h"
 #include "qemu/thread.h"
 #include "io/channel.h"
+#include "exec/hwaddr.h"
 
 #define REMOTE_MAX_FDS 8
 
@@ -XXX,XX +XXX,XX @@
  *
  */
 typedef enum {
+    MPQEMU_CMD_SYNC_SYSMEM,
     MPQEMU_CMD_MAX,
 } MPQemuCmd;
 
+typedef struct {
+    hwaddr gpas[REMOTE_MAX_FDS];
+    uint64_t sizes[REMOTE_MAX_FDS];
+    off_t offsets[REMOTE_MAX_FDS];
+} SyncSysmemMsg;
+
 /**
  * MPQemuMsg:
  * @cmd: The remote command
@@ -XXX,XX +XXX,XX @@ typedef enum {
  * MPQemuMsg Format of the message sent to the remote device from QEMU.
  *
  */
+
 typedef struct {
     int cmd;
     size_t size;
 
     union {
         uint64_t u64;
+        SyncSysmemMsg sync_sysmem;
     } data;
 
     int fds[REMOTE_MAX_FDS];
diff --git a/hw/remote/memory.c b/hw/remote/memory.c
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/hw/remote/memory.c
@@ -XXX,XX +XXX,XX @@
+/*
+ * Memory manager for remote device
+ *
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+
+#include "hw/remote/memory.h"
+#include "exec/address-spaces.h"
+#include "exec/ram_addr.h"
+#include "qapi/error.h"
+
+static void remote_sysmem_reset(void)
+{
+    MemoryRegion *sysmem, *subregion, *next;
+
+    sysmem = get_system_memory();
+
+    QTAILQ_FOREACH_SAFE(subregion, &sysmem->subregions, subregions_link, next) {
+        if (subregion->ram) {
+            memory_region_del_subregion(sysmem, subregion);
+            object_unparent(OBJECT(subregion));
+        }
+    }
+}
+
+void remote_sysmem_reconfig(MPQemuMsg *msg, Error **errp)
+{
+    ERRP_GUARD();
+    SyncSysmemMsg *sysmem_info = &msg->data.sync_sysmem;
+    MemoryRegion *sysmem, *subregion;
+    static unsigned int suffix;
+    int region;
+
+    sysmem = get_system_memory();
+
+    remote_sysmem_reset();
+
+    for (region = 0; region < msg->num_fds; region++) {
+        g_autofree char *name;
+        subregion = g_new(MemoryRegion, 1);
+        name = g_strdup_printf("remote-mem-%u", suffix++);
+        memory_region_init_ram_from_fd(subregion, NULL,
+                                       name, sysmem_info->sizes[region],
+                                       true, msg->fds[region],
+                                       sysmem_info->offsets[region],
+                                       errp);
+
+        if (*errp) {
+            g_free(subregion);
+            remote_sysmem_reset();
+            return;
+        }
+
+        memory_region_add_subregion(sysmem, sysmem_info->gpas[region],
+                                    subregion);
+
+    }
+}
diff --git a/hw/remote/mpqemu-link.c b/hw/remote/mpqemu-link.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/mpqemu-link.c
+++ b/hw/remote/mpqemu-link.c
@@ -XXX,XX +XXX,XX @@ bool mpqemu_msg_valid(MPQemuMsg *msg)
         }
     }
 
+     /* Verify message specific fields. */
+    switch (msg->cmd) {
+    case MPQEMU_CMD_SYNC_SYSMEM:
+        if (msg->num_fds == 0 || msg->size != sizeof(SyncSysmemMsg)) {
+            return false;
+        }
+        break;
+    default:
+        break;
+    }
+
     return true;
 }
diff --git a/hw/remote/meson.build b/hw/remote/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/meson.build
+++ b/hw/remote/meson.build
@@ -XXX,XX +XXX,XX @@ remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('mpqemu-link.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('message.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('remote-obj.c'))
 
+specific_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('memory.c'))
+
 softmmu_ss.add_all(when: 'CONFIG_MULTIPROCESS', if_true: remote_ss)
-- 
2.29.2

From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

Defines a PCI Device proxy object as a child of TYPE_PCI_DEVICE.

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: b5186ebfedf8e557044d09a768846c59230ad3a7.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 MAINTAINERS               |  2 +
 include/hw/remote/proxy.h | 33 +++++++++++++
 hw/remote/proxy.c         | 99 +++++++++++++++++++++++++++++++++++++++
 hw/remote/meson.build     |  1 +
 4 files changed, 135 insertions(+)
 create mode 100644 include/hw/remote/proxy.h
 create mode 100644 hw/remote/proxy.c

diff --git a/MAINTAINERS b/MAINTAINERS
index XXXXXXX..XXXXXXX 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -XXX,XX +XXX,XX @@ F: hw/remote/message.c
 F: hw/remote/remote-obj.c
 F: include/hw/remote/memory.h
 F: hw/remote/memory.c
+F: hw/remote/proxy.c
+F: include/hw/remote/proxy.h
 
 Build and test automation
 -------------------------
diff --git a/include/hw/remote/proxy.h b/include/hw/remote/proxy.h
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/include/hw/remote/proxy.h
@@ -XXX,XX +XXX,XX @@
+/*
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef PROXY_H
+#define PROXY_H
+
+#include "hw/pci/pci.h"
+#include "io/channel.h"
+
+#define TYPE_PCI_PROXY_DEV "x-pci-proxy-dev"
+OBJECT_DECLARE_SIMPLE_TYPE(PCIProxyDev, PCI_PROXY_DEV)
+
+struct PCIProxyDev {
+    PCIDevice parent_dev;
+    char *fd;
+
+    /*
+     * Mutex used to protect the QIOChannel fd from
+     * the concurrent access by the VCPUs since proxy
+     * blocks while awaiting for the replies from the
+     * process remote.
+     */
+    QemuMutex io_mutex;
+    QIOChannel *ioc;
+    Error *migration_blocker;
+};
+
+#endif /* PROXY_H */
diff --git a/hw/remote/proxy.c b/hw/remote/proxy.c
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/hw/remote/proxy.c
@@ -XXX,XX +XXX,XX @@
+/*
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+
+#include "hw/remote/proxy.h"
+#include "hw/pci/pci.h"
+#include "qapi/error.h"
+#include "io/channel-util.h"
+#include "hw/qdev-properties.h"
+#include "monitor/monitor.h"
+#include "migration/blocker.h"
+#include "qemu/sockets.h"
+
+static void pci_proxy_dev_realize(PCIDevice *device, Error **errp)
+{
+    ERRP_GUARD();
+    PCIProxyDev *dev = PCI_PROXY_DEV(device);
+    int fd;
+
+    if (!dev->fd) {
+        error_setg(errp, "fd parameter not specified for %s",
+                   DEVICE(device)->id);
+        return;
+    }
+
+    fd = monitor_fd_param(monitor_cur(), dev->fd, errp);
+    if (fd == -1) {
+        error_prepend(errp, "proxy: unable to parse fd %s: ", dev->fd);
+        return;
+    }
+
+    if (!fd_is_socket(fd)) {
+        error_setg(errp, "proxy: fd %d is not a socket", fd);
+        close(fd);
+        return;
+    }
+
+    dev->ioc = qio_channel_new_fd(fd, errp);
+
+    error_setg(&dev->migration_blocker, "%s does not support migration",
+               TYPE_PCI_PROXY_DEV);
+    migrate_add_blocker(dev->migration_blocker, errp);
+
+    qemu_mutex_init(&dev->io_mutex);
+    qio_channel_set_blocking(dev->ioc, true, NULL);
+}
+
+static void pci_proxy_dev_exit(PCIDevice *pdev)
+{
+    PCIProxyDev *dev = PCI_PROXY_DEV(pdev);
+
+    if (dev->ioc) {
+        qio_channel_close(dev->ioc, NULL);
+    }
+
+    migrate_del_blocker(dev->migration_blocker);
+
+    error_free(dev->migration_blocker);
+}
+
+static Property proxy_properties[] = {
+    DEFINE_PROP_STRING("fd", PCIProxyDev, fd),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void pci_proxy_dev_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
+
+    k->realize = pci_proxy_dev_realize;
+    k->exit = pci_proxy_dev_exit;
+    device_class_set_props(dc, proxy_properties);
+}
+
+static const TypeInfo pci_proxy_dev_type_info = {
+    .name          = TYPE_PCI_PROXY_DEV,
+    .parent        = TYPE_PCI_DEVICE,
+    .instance_size = sizeof(PCIProxyDev),
+    .class_init    = pci_proxy_dev_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { INTERFACE_CONVENTIONAL_PCI_DEVICE },
+        { },
+    },
+};
+
+static void pci_proxy_dev_register_types(void)
+{
+    type_register_static(&pci_proxy_dev_type_info);
+}
+
+type_init(pci_proxy_dev_register_types)
diff --git a/hw/remote/meson.build b/hw/remote/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/meson.build
+++ b/hw/remote/meson.build
@@ -XXX,XX +XXX,XX @@ remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('machine.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('mpqemu-link.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('message.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('remote-obj.c'))
+remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('proxy.c'))
 
 specific_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('memory.c'))
 
-- 
2.29.2

From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: d54edb4176361eed86b903e8f27058363b6c83b3.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 include/hw/remote/mpqemu-link.h |  4 ++++
 hw/remote/mpqemu-link.c         | 34 +++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/include/hw/remote/mpqemu-link.h b/include/hw/remote/mpqemu-link.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/remote/mpqemu-link.h
+++ b/include/hw/remote/mpqemu-link.h
@@ -XXX,XX +XXX,XX @@
 #include "qemu/thread.h"
 #include "io/channel.h"
 #include "exec/hwaddr.h"
+#include "io/channel-socket.h"
+#include "hw/remote/proxy.h"
 
 #define REMOTE_MAX_FDS 8
 
@@ -XXX,XX +XXX,XX @@ typedef struct {
 bool mpqemu_msg_send(MPQemuMsg *msg, QIOChannel *ioc, Error **errp);
 bool mpqemu_msg_recv(MPQemuMsg *msg, QIOChannel *ioc, Error **errp);
 
+uint64_t mpqemu_msg_send_and_await_reply(MPQemuMsg *msg, PCIProxyDev *pdev,
+                                         Error **errp);
 bool mpqemu_msg_valid(MPQemuMsg *msg);
 
 #endif
diff --git a/hw/remote/mpqemu-link.c b/hw/remote/mpqemu-link.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/mpqemu-link.c
+++ b/hw/remote/mpqemu-link.c
@@ -XXX,XX +XXX,XX @@ fail:
     return ret;
 }
 
+/*
+ * Send msg and wait for a reply with command code RET_MSG.
+ * Returns the message received of size u64 or UINT64_MAX
+ * on error.
+ * Called from VCPU thread in non-coroutine context.
+ * Used by the Proxy object to communicate to remote processes.
+ */
+uint64_t mpqemu_msg_send_and_await_reply(MPQemuMsg *msg, PCIProxyDev *pdev,
+                                         Error **errp)
+{
+    ERRP_GUARD();
+    MPQemuMsg msg_reply = {0};
+    uint64_t ret = UINT64_MAX;
+
+    assert(!qemu_in_coroutine());
+
+    QEMU_LOCK_GUARD(&pdev->io_mutex);
+    if (!mpqemu_msg_send(msg, pdev->ioc, errp)) {
+        return ret;
+    }
+
+    if (!mpqemu_msg_recv(&msg_reply, pdev->ioc, errp)) {
+        return ret;
+    }
+
+    if (!mpqemu_msg_valid(&msg_reply)) {
+        error_setg(errp, "ERROR: Invalid reply received for command %d",
+                         msg->cmd);
+        return ret;
+    }
+
+    return msg_reply.data.u64;
+}
+
 bool mpqemu_msg_valid(MPQemuMsg *msg)
 {
     if (msg->cmd >= MPQEMU_CMD_MAX && msg->cmd < 0) {
-- 
2.29.2

From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

The Proxy Object sends the PCI config space accesses as messages
to the remote process over the communication channel

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: d3c94f4618813234655356c60e6f0d0362ff42d6.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 include/hw/remote/mpqemu-link.h | 10 ++++++
 hw/remote/message.c             | 60 +++++++++++++++++++++++++++++++++
 hw/remote/mpqemu-link.c         |  8 ++++-
 hw/remote/proxy.c               | 55 ++++++++++++++++++++++++++++++
 4 files changed, 132 insertions(+), 1 deletion(-)

diff --git a/include/hw/remote/mpqemu-link.h b/include/hw/remote/mpqemu-link.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/remote/mpqemu-link.h
+++ b/include/hw/remote/mpqemu-link.h
@@ -XXX,XX +XXX,XX @@
  */
 typedef enum {
     MPQEMU_CMD_SYNC_SYSMEM,
+    MPQEMU_CMD_RET,
+    MPQEMU_CMD_PCI_CFGWRITE,
+    MPQEMU_CMD_PCI_CFGREAD,
     MPQEMU_CMD_MAX,
 } MPQemuCmd;
 
@@ -XXX,XX +XXX,XX @@ typedef struct {
     off_t offsets[REMOTE_MAX_FDS];
 } SyncSysmemMsg;
 
+typedef struct {
+    uint32_t addr;
+    uint32_t val;
+    int len;
+} PciConfDataMsg;
+
 /**
  * MPQemuMsg:
  * @cmd: The remote command
@@ -XXX,XX +XXX,XX @@ typedef struct {
 
     union {
         uint64_t u64;
+        PciConfDataMsg pci_conf_data;
         SyncSysmemMsg sync_sysmem;
     } data;
 
diff --git a/hw/remote/message.c b/hw/remote/message.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/message.c
+++ b/hw/remote/message.c
@@ -XXX,XX +XXX,XX @@
 #include "hw/remote/mpqemu-link.h"
 #include "qapi/error.h"
 #include "sysemu/runstate.h"
+#include "hw/pci/pci.h"
+
+static void process_config_write(QIOChannel *ioc, PCIDevice *dev,
+                                 MPQemuMsg *msg, Error **errp);
+static void process_config_read(QIOChannel *ioc, PCIDevice *dev,
+                                MPQemuMsg *msg, Error **errp);
 
 void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
 {
@@ -XXX,XX +XXX,XX @@ void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
         }
 
         switch (msg.cmd) {
+        case MPQEMU_CMD_PCI_CFGWRITE:
+            process_config_write(com->ioc, pci_dev, &msg, &local_err);
+            break;
+        case MPQEMU_CMD_PCI_CFGREAD:
+            process_config_read(com->ioc, pci_dev, &msg, &local_err);
+            break;
         default:
             error_setg(&local_err,
                        "Unknown command (%d) received for device %s"
@@ -XXX,XX +XXX,XX @@ void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
         qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
     }
 }
+
+static void process_config_write(QIOChannel *ioc, PCIDevice *dev,
+                                 MPQemuMsg *msg, Error **errp)
+{
+    ERRP_GUARD();
+    PciConfDataMsg *conf = (PciConfDataMsg *)&msg->data.pci_conf_data;
+    MPQemuMsg ret = { 0 };
+
+    if ((conf->addr + sizeof(conf->val)) > pci_config_size(dev)) {
+        error_setg(errp, "Bad address for PCI config write, pid "FMT_pid".",
+                   getpid());
+        ret.data.u64 = UINT64_MAX;
+    } else {
+        pci_default_write_config(dev, conf->addr, conf->val, conf->len);
+    }
+
+    ret.cmd = MPQEMU_CMD_RET;
+    ret.size = sizeof(ret.data.u64);
+
+    if (!mpqemu_msg_send(&ret, ioc, NULL)) {
+        error_prepend(errp, "Error returning code to proxy, pid "FMT_pid": ",
+                      getpid());
+    }
+}
+
+static void process_config_read(QIOChannel *ioc, PCIDevice *dev,
+                                MPQemuMsg *msg, Error **errp)
+{
+    ERRP_GUARD();
+    PciConfDataMsg *conf = (PciConfDataMsg *)&msg->data.pci_conf_data;
+    MPQemuMsg ret = { 0 };
+
+    if ((conf->addr + sizeof(conf->val)) > pci_config_size(dev)) {
+        error_setg(errp, "Bad address for PCI config read, pid "FMT_pid".",
+                   getpid());
+        ret.data.u64 = UINT64_MAX;
+    } else {
+        ret.data.u64 = pci_default_read_config(dev, conf->addr, conf->len);
+    }
+
+    ret.cmd = MPQEMU_CMD_RET;
+    ret.size = sizeof(ret.data.u64);
+
+    if (!mpqemu_msg_send(&ret, ioc, NULL)) {
+        error_prepend(errp, "Error returning code to proxy, pid "FMT_pid": ",
+                      getpid());
+    }
+}
diff --git a/hw/remote/mpqemu-link.c b/hw/remote/mpqemu-link.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/mpqemu-link.c
+++ b/hw/remote/mpqemu-link.c
@@ -XXX,XX +XXX,XX @@ uint64_t mpqemu_msg_send_and_await_reply(MPQemuMsg *msg, PCIProxyDev *pdev,
         return ret;
     }
 
-    if (!mpqemu_msg_valid(&msg_reply)) {
+    if (!mpqemu_msg_valid(&msg_reply) || msg_reply.cmd != MPQEMU_CMD_RET) {
         error_setg(errp, "ERROR: Invalid reply received for command %d",
                          msg->cmd);
         return ret;
@@ -XXX,XX +XXX,XX @@ bool mpqemu_msg_valid(MPQemuMsg *msg)
             return false;
         }
         break;
+    case MPQEMU_CMD_PCI_CFGWRITE:
+    case MPQEMU_CMD_PCI_CFGREAD:
+        if (msg->size != sizeof(PciConfDataMsg)) {
+            return false;
+        }
+        break;
     default:
         break;
     }
diff --git a/hw/remote/proxy.c b/hw/remote/proxy.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/proxy.c
+++ b/hw/remote/proxy.c
@@ -XXX,XX +XXX,XX @@
 #include "monitor/monitor.h"
 #include "migration/blocker.h"
 #include "qemu/sockets.h"
+#include "hw/remote/mpqemu-link.h"
+#include "qemu/error-report.h"
 
 static void pci_proxy_dev_realize(PCIDevice *device, Error **errp)
 {
@@ -XXX,XX +XXX,XX @@ static void pci_proxy_dev_exit(PCIDevice *pdev)
     error_free(dev->migration_blocker);
 }
 
+static void config_op_send(PCIProxyDev *pdev, uint32_t addr, uint32_t *val,
+                           int len, unsigned int op)
+{
+    MPQemuMsg msg = { 0 };
+    uint64_t ret = -EINVAL;
+    Error *local_err = NULL;
+
+    msg.cmd = op;
+    msg.data.pci_conf_data.addr = addr;
+    msg.data.pci_conf_data.val = (op == MPQEMU_CMD_PCI_CFGWRITE) ? *val : 0;
+    msg.data.pci_conf_data.len = len;
+    msg.size = sizeof(PciConfDataMsg);
+
+    ret = mpqemu_msg_send_and_await_reply(&msg, pdev, &local_err);
+    if (local_err) {
+        error_report_err(local_err);
+    }
+
+    if (ret == UINT64_MAX) {
+        error_report("Failed to perform PCI config %s operation",
+                     (op == MPQEMU_CMD_PCI_CFGREAD) ? "READ" : "WRITE");
+    }
+
+    if (op == MPQEMU_CMD_PCI_CFGREAD) {
+        *val = (uint32_t)ret;
+    }
+}
+
+static uint32_t pci_proxy_read_config(PCIDevice *d, uint32_t addr, int len)
+{
+    uint32_t val;
+
+    config_op_send(PCI_PROXY_DEV(d), addr, &val, len, MPQEMU_CMD_PCI_CFGREAD);
+
+    return val;
+}
+
+static void pci_proxy_write_config(PCIDevice *d, uint32_t addr, uint32_t val,
+                                   int len)
+{
+    /*
+     * Some of the functions access the copy of remote device's PCI config
+     * space which is cached in the proxy device. Therefore, maintain
+     * it updated.
+     */
+    pci_default_write_config(d, addr, val, len);
+
+    config_op_send(PCI_PROXY_DEV(d), addr, &val, len, MPQEMU_CMD_PCI_CFGWRITE);
+}
+
 static Property proxy_properties[] = {
     DEFINE_PROP_STRING("fd", PCIProxyDev, fd),
     DEFINE_PROP_END_OF_LIST(),
@@ -XXX,XX +XXX,XX @@ static void pci_proxy_dev_class_init(ObjectClass *klass, void *data)
 
     k->realize = pci_proxy_dev_realize;
     k->exit = pci_proxy_dev_exit;
+    k->config_read = pci_proxy_read_config;
+    k->config_write = pci_proxy_write_config;
+
     device_class_set_props(dc, proxy_properties);
 }
 
-- 
2.29.2

From: Jagannathan Raman <jag.raman@oracle.com>

Proxy device object implements handler for PCI BAR writes and reads.
The handler uses BAR_WRITE/BAR_READ message to communicate to the
remote process with the BAR address and value to be written/read.
The remote process implements handler for BAR_WRITE/BAR_READ
message.

Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: a8b76714a9688be5552c4c92d089bc9e8a4707ff.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 include/hw/remote/mpqemu-link.h | 10 ++++
 include/hw/remote/proxy.h       |  9 ++++
 hw/remote/message.c             | 83 +++++++++++++++++++++++++++++++++
 hw/remote/mpqemu-link.c         |  6 +++
 hw/remote/proxy.c               | 60 ++++++++++++++++++++++++
 5 files changed, 168 insertions(+)

diff --git a/include/hw/remote/mpqemu-link.h b/include/hw/remote/mpqemu-link.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/remote/mpqemu-link.h
+++ b/include/hw/remote/mpqemu-link.h
@@ -XXX,XX +XXX,XX @@ typedef enum {
     MPQEMU_CMD_RET,
     MPQEMU_CMD_PCI_CFGWRITE,
     MPQEMU_CMD_PCI_CFGREAD,
+    MPQEMU_CMD_BAR_WRITE,
+    MPQEMU_CMD_BAR_READ,
     MPQEMU_CMD_MAX,
 } MPQemuCmd;
 
@@ -XXX,XX +XXX,XX @@ typedef struct {
     int len;
 } PciConfDataMsg;
 
+typedef struct {
+    hwaddr addr;
+    uint64_t val;
+    unsigned size;
+    bool memory;
+} BarAccessMsg;
+
 /**
  * MPQemuMsg:
  * @cmd: The remote command
@@ -XXX,XX +XXX,XX @@ typedef struct {
         uint64_t u64;
         PciConfDataMsg pci_conf_data;
         SyncSysmemMsg sync_sysmem;
+        BarAccessMsg bar_access;
     } data;
 
     int fds[REMOTE_MAX_FDS];
diff --git a/include/hw/remote/proxy.h b/include/hw/remote/proxy.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/remote/proxy.h
+++ b/include/hw/remote/proxy.h
@@ -XXX,XX +XXX,XX @@
 #define TYPE_PCI_PROXY_DEV "x-pci-proxy-dev"
 OBJECT_DECLARE_SIMPLE_TYPE(PCIProxyDev, PCI_PROXY_DEV)
 
+typedef struct ProxyMemoryRegion {
+    PCIProxyDev *dev;
+    MemoryRegion mr;
+    bool memory;
+    bool present;
+    uint8_t type;
+} ProxyMemoryRegion;
+
 struct PCIProxyDev {
     PCIDevice parent_dev;
     char *fd;
@@ -XXX,XX +XXX,XX @@ struct PCIProxyDev {
     QemuMutex io_mutex;
     QIOChannel *ioc;
     Error *migration_blocker;
+    ProxyMemoryRegion region[PCI_NUM_REGIONS];
 };
 
 #endif /* PROXY_H */
diff --git a/hw/remote/message.c b/hw/remote/message.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/message.c
+++ b/hw/remote/message.c
@@ -XXX,XX +XXX,XX @@
 #include "qapi/error.h"
 #include "sysemu/runstate.h"
 #include "hw/pci/pci.h"
+#include "exec/memattrs.h"
 
 static void process_config_write(QIOChannel *ioc, PCIDevice *dev,
                                  MPQemuMsg *msg, Error **errp);
 static void process_config_read(QIOChannel *ioc, PCIDevice *dev,
                                 MPQemuMsg *msg, Error **errp);
+static void process_bar_write(QIOChannel *ioc, MPQemuMsg *msg, Error **errp);
+static void process_bar_read(QIOChannel *ioc, MPQemuMsg *msg, Error **errp);
 
 void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
 {
@@ -XXX,XX +XXX,XX @@ void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
         case MPQEMU_CMD_PCI_CFGREAD:
             process_config_read(com->ioc, pci_dev, &msg, &local_err);
             break;
+        case MPQEMU_CMD_BAR_WRITE:
+            process_bar_write(com->ioc, &msg, &local_err);
+            break;
+        case MPQEMU_CMD_BAR_READ:
+            process_bar_read(com->ioc, &msg, &local_err);
+            break;
         default:
             error_setg(&local_err,
                        "Unknown command (%d) received for device %s"
@@ -XXX,XX +XXX,XX @@ static void process_config_read(QIOChannel *ioc, PCIDevice *dev,
                       getpid());
     }
 }
+
+static void process_bar_write(QIOChannel *ioc, MPQemuMsg *msg, Error **errp)
+{
+    ERRP_GUARD();
+    BarAccessMsg *bar_access = &msg->data.bar_access;
+    AddressSpace *as =
+        bar_access->memory ? &address_space_memory : &address_space_io;
+    MPQemuMsg ret = { 0 };
+    MemTxResult res;
+    uint64_t val;
+
+    if (!is_power_of_2(bar_access->size) ||
+       (bar_access->size > sizeof(uint64_t))) {
+        ret.data.u64 = UINT64_MAX;
+        goto fail;
+    }
+
+    val = cpu_to_le64(bar_access->val);
+
+    res = address_space_rw(as, bar_access->addr, MEMTXATTRS_UNSPECIFIED,
+                           (void *)&val, bar_access->size, true);
+
+    if (res != MEMTX_OK) {
+        error_setg(errp, "Bad address %"PRIx64" for mem write, pid "FMT_pid".",
+                   bar_access->addr, getpid());
+        ret.data.u64 = -1;
+    }
+
+fail:
+    ret.cmd = MPQEMU_CMD_RET;
+    ret.size = sizeof(ret.data.u64);
+
+    if (!mpqemu_msg_send(&ret, ioc, NULL)) {
+        error_prepend(errp, "Error returning code to proxy, pid "FMT_pid": ",
+                      getpid());
+    }
+}
+
+static void process_bar_read(QIOChannel *ioc, MPQemuMsg *msg, Error **errp)
+{
+    ERRP_GUARD();
+    BarAccessMsg *bar_access = &msg->data.bar_access;
+    MPQemuMsg ret = { 0 };
+    AddressSpace *as;
+    MemTxResult res;
+    uint64_t val = 0;
+
+    as = bar_access->memory ? &address_space_memory : &address_space_io;
+
+    if (!is_power_of_2(bar_access->size) ||
+       (bar_access->size > sizeof(uint64_t))) {
+        val = UINT64_MAX;
+        goto fail;
+    }
+
+    res = address_space_rw(as, bar_access->addr, MEMTXATTRS_UNSPECIFIED,
+                           (void *)&val, bar_access->size, false);
+
+    if (res != MEMTX_OK) {
+        error_setg(errp, "Bad address %"PRIx64" for mem read, pid "FMT_pid".",
+                   bar_access->addr, getpid());
+        val = UINT64_MAX;
+    }
+
+fail:
+    ret.cmd = MPQEMU_CMD_RET;
+    ret.data.u64 = le64_to_cpu(val);
+    ret.size = sizeof(ret.data.u64);
+
+    if (!mpqemu_msg_send(&ret, ioc, NULL)) {
+        error_prepend(errp, "Error returning code to proxy, pid "FMT_pid": ",
+                      getpid());
+    }
+}
diff --git a/hw/remote/mpqemu-link.c b/hw/remote/mpqemu-link.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/mpqemu-link.c
+++ b/hw/remote/mpqemu-link.c
@@ -XXX,XX +XXX,XX @@ bool mpqemu_msg_valid(MPQemuMsg *msg)
             return false;
         }
         break;
+    case MPQEMU_CMD_BAR_WRITE:
+    case MPQEMU_CMD_BAR_READ:
+        if ((msg->size != sizeof(BarAccessMsg)) || (msg->num_fds != 0)) {
+            return false;
+        }
+        break;
     default:
         break;
     }
diff --git a/hw/remote/proxy.c b/hw/remote/proxy.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/proxy.c
+++ b/hw/remote/proxy.c
@@ -XXX,XX +XXX,XX @@ static void pci_proxy_dev_register_types(void)
 }
 
 type_init(pci_proxy_dev_register_types)
+
+static void send_bar_access_msg(PCIProxyDev *pdev, MemoryRegion *mr,
+                                bool write, hwaddr addr, uint64_t *val,
+                                unsigned size, bool memory)
+{
+    MPQemuMsg msg = { 0 };
+    long ret = -EINVAL;
+    Error *local_err = NULL;
+
+    msg.size = sizeof(BarAccessMsg);
+    msg.data.bar_access.addr = mr->addr + addr;
+    msg.data.bar_access.size = size;
+    msg.data.bar_access.memory = memory;
+
+    if (write) {
+        msg.cmd = MPQEMU_CMD_BAR_WRITE;
+        msg.data.bar_access.val = *val;
+    } else {
+        msg.cmd = MPQEMU_CMD_BAR_READ;
+    }
+
+    ret = mpqemu_msg_send_and_await_reply(&msg, pdev, &local_err);
+    if (local_err) {
+        error_report_err(local_err);
+    }
+
+    if (!write) {
+        *val = ret;
+    }
+}
+
+static void proxy_bar_write(void *opaque, hwaddr addr, uint64_t val,
+                            unsigned size)
+{
+    ProxyMemoryRegion *pmr = opaque;
+
+    send_bar_access_msg(pmr->dev, &pmr->mr, true, addr, &val, size,
+                        pmr->memory);
+}
+
+static uint64_t proxy_bar_read(void *opaque, hwaddr addr, unsigned size)
+{
+    ProxyMemoryRegion *pmr = opaque;
+    uint64_t val;
+
+    send_bar_access_msg(pmr->dev, &pmr->mr, false, addr, &val, size,
+                        pmr->memory);
+
+    return val;
+}
+
+const MemoryRegionOps proxy_mr_ops = {
+    .read = proxy_bar_read,
+    .write = proxy_bar_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .impl = {
+        .min_access_size = 1,
+        .max_access_size = 8,
+    },
+};
-- 
2.29.2

From: Jagannathan Raman <jag.raman@oracle.com>

Add ProxyMemoryListener object which is used to keep the view of the RAM
in sync between QEMU and remote process.
A MemoryListener is registered for system-memory AddressSpace. The
listener sends SYNC_SYSMEM message to the remote process when memory
listener commits the changes to memory, the remote process receives
the message and processes it in the handler for SYNC_SYSMEM message.

Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 04fe4e6a9ca90d4f11ab6f59be7652f5b086a071.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 MAINTAINERS                               |   2 +
 include/hw/remote/proxy-memory-listener.h |  28 +++
 include/hw/remote/proxy.h                 |   2 +
 hw/remote/message.c                       |   4 +
 hw/remote/proxy-memory-listener.c         | 227 ++++++++++++++++++++++
 hw/remote/proxy.c                         |   6 +
 hw/remote/meson.build                     |   1 +
 7 files changed, 270 insertions(+)
 create mode 100644 include/hw/remote/proxy-memory-listener.h
 create mode 100644 hw/remote/proxy-memory-listener.c

diff --git a/MAINTAINERS b/MAINTAINERS
index XXXXXXX..XXXXXXX 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -XXX,XX +XXX,XX @@ F: include/hw/remote/memory.h
 F: hw/remote/memory.c
 F: hw/remote/proxy.c
 F: include/hw/remote/proxy.h
+F: hw/remote/proxy-memory-listener.c
+F: include/hw/remote/proxy-memory-listener.h
 
 Build and test automation
 -------------------------
diff --git a/include/hw/remote/proxy-memory-listener.h b/include/hw/remote/proxy-memory-listener.h
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/include/hw/remote/proxy-memory-listener.h
@@ -XXX,XX +XXX,XX @@
+/*
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef PROXY_MEMORY_LISTENER_H
+#define PROXY_MEMORY_LISTENER_H
+
+#include "exec/memory.h"
+#include "io/channel.h"
+
+typedef struct ProxyMemoryListener {
+    MemoryListener listener;
+
+    int n_mr_sections;
+    MemoryRegionSection *mr_sections;
+
+    QIOChannel *ioc;
+} ProxyMemoryListener;
+
+void proxy_memory_listener_configure(ProxyMemoryListener *proxy_listener,
+                                     QIOChannel *ioc);
+void proxy_memory_listener_deconfigure(ProxyMemoryListener *proxy_listener);
+
+#endif
diff --git a/include/hw/remote/proxy.h b/include/hw/remote/proxy.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/remote/proxy.h
+++ b/include/hw/remote/proxy.h
@@ -XXX,XX +XXX,XX @@
 
 #include "hw/pci/pci.h"
 #include "io/channel.h"
+#include "hw/remote/proxy-memory-listener.h"
 
 #define TYPE_PCI_PROXY_DEV "x-pci-proxy-dev"
 OBJECT_DECLARE_SIMPLE_TYPE(PCIProxyDev, PCI_PROXY_DEV)
@@ -XXX,XX +XXX,XX @@ struct PCIProxyDev {
     QemuMutex io_mutex;
     QIOChannel *ioc;
     Error *migration_blocker;
+    ProxyMemoryListener proxy_listener;
     ProxyMemoryRegion region[PCI_NUM_REGIONS];
 };
 
diff --git a/hw/remote/message.c b/hw/remote/message.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/message.c
+++ b/hw/remote/message.c
@@ -XXX,XX +XXX,XX @@
 #include "sysemu/runstate.h"
 #include "hw/pci/pci.h"
 #include "exec/memattrs.h"
+#include "hw/remote/memory.h"
 
 static void process_config_write(QIOChannel *ioc, PCIDevice *dev,
                                  MPQemuMsg *msg, Error **errp);
@@ -XXX,XX +XXX,XX @@ void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
         case MPQEMU_CMD_BAR_READ:
             process_bar_read(com->ioc, &msg, &local_err);
             break;
+        case MPQEMU_CMD_SYNC_SYSMEM:
+            remote_sysmem_reconfig(&msg, &local_err);
+            break;
         default:
             error_setg(&local_err,
                        "Unknown command (%d) received for device %s"
diff --git a/hw/remote/proxy-memory-listener.c b/hw/remote/proxy-memory-listener.c
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/hw/remote/proxy-memory-listener.c
@@ -XXX,XX +XXX,XX @@
+/*
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+
+#include "qemu/compiler.h"
+#include "qemu/int128.h"
+#include "qemu/range.h"
+#include "exec/memory.h"
+#include "exec/cpu-common.h"
+#include "cpu.h"
+#include "exec/ram_addr.h"
+#include "exec/address-spaces.h"
+#include "qapi/error.h"
+#include "hw/remote/mpqemu-link.h"
+#include "hw/remote/proxy-memory-listener.h"
+
+/*
+ * TODO: get_fd_from_hostaddr(), proxy_mrs_can_merge() and
+ * proxy_memory_listener_commit() defined below perform tasks similar to the
+ * functions defined in vhost-user.c. These functions are good candidates
+ * for refactoring.
+ *
+ */
+
+static void proxy_memory_listener_reset(MemoryListener *listener)
+{
+    ProxyMemoryListener *proxy_listener = container_of(listener,
+                                                       ProxyMemoryListener,
+                                                       listener);
+    int mrs;
+
+    for (mrs = 0; mrs < proxy_listener->n_mr_sections; mrs++) {
+        memory_region_unref(proxy_listener->mr_sections[mrs].mr);
+    }
+
+    g_free(proxy_listener->mr_sections);
+    proxy_listener->mr_sections = NULL;
+    proxy_listener->n_mr_sections = 0;
+}
+
+static int get_fd_from_hostaddr(uint64_t host, ram_addr_t *offset)
+{
+    MemoryRegion *mr;
+    ram_addr_t off;
+
+    /**
+     * Assumes that the host address is a valid address as it's
+     * coming from the MemoryListener system. In the case host
+     * address is not valid, the following call would return
+     * the default subregion of "system_memory" region, and
+     * not NULL. So it's not possible to check for NULL here.
+     */
+    mr = memory_region_from_host((void *)(uintptr_t)host, &off);
+
+    if (offset) {
+        *offset = off;
+    }
+
+    return memory_region_get_fd(mr);
+}
+
+static bool proxy_mrs_can_merge(uint64_t host, uint64_t prev_host, size_t size)
+{
+    if (((prev_host + size) != host)) {
+        return false;
+    }
+
+    if (get_fd_from_hostaddr(host, NULL) !=
+            get_fd_from_hostaddr(prev_host, NULL)) {
+        return false;
+    }
+
+    return true;
+}
+
+static bool try_merge(ProxyMemoryListener *proxy_listener,
+                      MemoryRegionSection *section)
+{
+    uint64_t mrs_size, mrs_gpa, mrs_page;
+    MemoryRegionSection *prev_sec;
+    bool merged = false;
+    uintptr_t mrs_host;
+    RAMBlock *mrs_rb;
+
+    if (!proxy_listener->n_mr_sections) {
+        return false;
+    }
+
+    mrs_rb = section->mr->ram_block;
+    mrs_page = (uint64_t)qemu_ram_pagesize(mrs_rb);
+    mrs_size = int128_get64(section->size);
+    mrs_gpa = section->offset_within_address_space;
+    mrs_host = (uintptr_t)memory_region_get_ram_ptr(section->mr) +
+               section->offset_within_region;
+
+    if (get_fd_from_hostaddr(mrs_host, NULL) < 0) {
+        return true;
+    }
+
+    mrs_host = mrs_host & ~(mrs_page - 1);
+    mrs_gpa = mrs_gpa & ~(mrs_page - 1);
+    mrs_size = ROUND_UP(mrs_size, mrs_page);
+
+    prev_sec = proxy_listener->mr_sections +
+               (proxy_listener->n_mr_sections - 1);
+    uint64_t prev_gpa_start = prev_sec->offset_within_address_space;
+    uint64_t prev_size = int128_get64(prev_sec->size);
+    uint64_t prev_gpa_end   = range_get_last(prev_gpa_start, prev_size);
+    uint64_t prev_host_start =
+        (uintptr_t)memory_region_get_ram_ptr(prev_sec->mr) +
+        prev_sec->offset_within_region;
+    uint64_t prev_host_end = range_get_last(prev_host_start, prev_size);
+
+    if (mrs_gpa <= (prev_gpa_end + 1)) {
+        g_assert(mrs_gpa > prev_gpa_start);
+
+        if ((section->mr == prev_sec->mr) &&
+            proxy_mrs_can_merge(mrs_host, prev_host_start,
+                                (mrs_gpa - prev_gpa_start))) {
+            uint64_t max_end = MAX(prev_host_end, mrs_host + mrs_size);
+            merged = true;
+            prev_sec->offset_within_address_space =
+                MIN(prev_gpa_start, mrs_gpa);
+            prev_sec->offset_within_region =
+                MIN(prev_host_start, mrs_host) -
+                (uintptr_t)memory_region_get_ram_ptr(prev_sec->mr);
+            prev_sec->size = int128_make64(max_end - MIN(prev_host_start,
+                                                         mrs_host));
+        }
+    }
+
+    return merged;
+}
+
+static void proxy_memory_listener_region_addnop(MemoryListener *listener,
+                                                MemoryRegionSection *section)
+{
+    ProxyMemoryListener *proxy_listener = container_of(listener,
+                                                       ProxyMemoryListener,
+                                                       listener);
+
+    if (!memory_region_is_ram(section->mr) ||
+            memory_region_is_rom(section->mr)) {
+        return;
+    }
+
+    if (try_merge(proxy_listener, section)) {
+        return;
+    }
+
+    ++proxy_listener->n_mr_sections;
+    proxy_listener->mr_sections = g_renew(MemoryRegionSection,
+                                          proxy_listener->mr_sections,
+                                          proxy_listener->n_mr_sections);
+    proxy_listener->mr_sections[proxy_listener->n_mr_sections - 1] = *section;
+    proxy_listener->mr_sections[proxy_listener->n_mr_sections - 1].fv = NULL;
+    memory_region_ref(section->mr);
+}
+
+static void proxy_memory_listener_commit(MemoryListener *listener)
+{
+    ProxyMemoryListener *proxy_listener = container_of(listener,
+                                                       ProxyMemoryListener,
+                                                       listener);
+    MPQemuMsg msg;
+    MemoryRegionSection *section;
+    ram_addr_t offset;
+    uintptr_t host_addr;
+    int region;
+    Error *local_err = NULL;
+
+    memset(&msg, 0, sizeof(MPQemuMsg));
+
+    msg.cmd = MPQEMU_CMD_SYNC_SYSMEM;
+    msg.num_fds = proxy_listener->n_mr_sections;
+    msg.size = sizeof(SyncSysmemMsg);
+    if (msg.num_fds > REMOTE_MAX_FDS) {
+        error_report("Number of fds is more than %d", REMOTE_MAX_FDS);
+        return;
+    }
+
+    for (region = 0; region < proxy_listener->n_mr_sections; region++) {
+        section = &proxy_listener->mr_sections[region];
+        msg.data.sync_sysmem.gpas[region] =
+            section->offset_within_address_space;
+        msg.data.sync_sysmem.sizes[region] = int128_get64(section->size);
+        host_addr = (uintptr_t)memory_region_get_ram_ptr(section->mr) +
+                    section->offset_within_region;
+        msg.fds[region] = get_fd_from_hostaddr(host_addr, &offset);
+        msg.data.sync_sysmem.offsets[region] = offset;
+    }
+    if (!mpqemu_msg_send(&msg, proxy_listener->ioc, &local_err)) {
+        error_report_err(local_err);
+    }
+}
+
+void proxy_memory_listener_deconfigure(ProxyMemoryListener *proxy_listener)
+{
+    memory_listener_unregister(&proxy_listener->listener);
+
+    proxy_memory_listener_reset(&proxy_listener->listener);
+}
+
+void proxy_memory_listener_configure(ProxyMemoryListener *proxy_listener,
+                                     QIOChannel *ioc)
+{
+    proxy_listener->n_mr_sections = 0;
+    proxy_listener->mr_sections = NULL;
+
+    proxy_listener->ioc = ioc;
+
+    proxy_listener->listener.begin = proxy_memory_listener_reset;
+    proxy_listener->listener.commit = proxy_memory_listener_commit;
+    proxy_listener->listener.region_add = proxy_memory_listener_region_addnop;
+    proxy_listener->listener.region_nop = proxy_memory_listener_region_addnop;
+    proxy_listener->listener.priority = 10;
+
+    memory_listener_register(&proxy_listener->listener,
+                             &address_space_memory);
+}
diff --git a/hw/remote/proxy.c b/hw/remote/proxy.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/proxy.c
+++ b/hw/remote/proxy.c
@@ -XXX,XX +XXX,XX @@
 #include "qemu/sockets.h"
 #include "hw/remote/mpqemu-link.h"
 #include "qemu/error-report.h"
+#include "hw/remote/proxy-memory-listener.h"
+#include "qom/object.h"
 
 static void pci_proxy_dev_realize(PCIDevice *device, Error **errp)
 {
@@ -XXX,XX +XXX,XX @@ static void pci_proxy_dev_realize(PCIDevice *device, Error **errp)
 
     qemu_mutex_init(&dev->io_mutex);
     qio_channel_set_blocking(dev->ioc, true, NULL);
+
+    proxy_memory_listener_configure(&dev->proxy_listener, dev->ioc);
 }
 
 static void pci_proxy_dev_exit(PCIDevice *pdev)
@@ -XXX,XX +XXX,XX @@ static void pci_proxy_dev_exit(PCIDevice *pdev)
     migrate_del_blocker(dev->migration_blocker);
 
     error_free(dev->migration_blocker);
+
+    proxy_memory_listener_deconfigure(&dev->proxy_listener);
 }
 
 static void config_op_send(PCIProxyDev *pdev, uint32_t addr, uint32_t *val,
diff --git a/hw/remote/meson.build b/hw/remote/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/meson.build
+++ b/hw/remote/meson.build
@@ -XXX,XX +XXX,XX @@ remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('remote-obj.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('proxy.c'))
 
 specific_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('memory.c'))
+specific_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('proxy-memory-listener.c'))
 
 softmmu_ss.add_all(when: 'CONFIG_MULTIPROCESS', if_true: remote_ss)
-- 
2.29.2

From: Jagannathan Raman <jag.raman@oracle.com>

IOHUB object is added to manage PCI IRQs. It uses KVM_IRQFD
ioctl to create irqfd to injecting PCI interrupts to the guest.
IOHUB object forwards the irqfd to the remote process. Remote process
uses this fd to directly send interrupts to the guest, bypassing QEMU.

Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 51d5c3d54e28a68b002e3875c59599c9f5a424a1.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 MAINTAINERS                     |   2 +
 include/hw/pci/pci_ids.h        |   3 +
 include/hw/remote/iohub.h       |  42 +++++++++++
 include/hw/remote/machine.h     |   2 +
 include/hw/remote/mpqemu-link.h |   1 +
 include/hw/remote/proxy.h       |   4 ++
 hw/remote/iohub.c               | 119 ++++++++++++++++++++++++++++++++
 hw/remote/machine.c             |  10 +++
 hw/remote/message.c             |   4 ++
 hw/remote/mpqemu-link.c         |   5 ++
 hw/remote/proxy.c               |  56 +++++++++++++++
 hw/remote/meson.build           |   1 +
 12 files changed, 249 insertions(+)
 create mode 100644 include/hw/remote/iohub.h
 create mode 100644 hw/remote/iohub.c

diff --git a/MAINTAINERS b/MAINTAINERS
index XXXXXXX..XXXXXXX 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -XXX,XX +XXX,XX @@ F: hw/remote/proxy.c
 F: include/hw/remote/proxy.h
 F: hw/remote/proxy-memory-listener.c
 F: include/hw/remote/proxy-memory-listener.h
+F: hw/remote/iohub.c
+F: include/hw/remote/iohub.h
 
 Build and test automation
 -------------------------
diff --git a/include/hw/pci/pci_ids.h b/include/hw/pci/pci_ids.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/pci/pci_ids.h
+++ b/include/hw/pci/pci_ids.h
@@ -XXX,XX +XXX,XX @@
 #define PCI_DEVICE_ID_SUN_SIMBA          0x5000
 #define PCI_DEVICE_ID_SUN_SABRE          0xa000
 
+#define PCI_VENDOR_ID_ORACLE             0x108e
+#define PCI_DEVICE_ID_REMOTE_IOHUB       0xb000
+
 #define PCI_VENDOR_ID_CMD                0x1095
 #define PCI_DEVICE_ID_CMD_646            0x0646
 
diff --git a/include/hw/remote/iohub.h b/include/hw/remote/iohub.h
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/include/hw/remote/iohub.h
@@ -XXX,XX +XXX,XX @@
+/*
+ * IO Hub for remote device
+ *
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef REMOTE_IOHUB_H
+#define REMOTE_IOHUB_H
+
+#include "hw/pci/pci.h"
+#include "qemu/event_notifier.h"
+#include "qemu/thread-posix.h"
+#include "hw/remote/mpqemu-link.h"
+
+#define REMOTE_IOHUB_NB_PIRQS    PCI_DEVFN_MAX
+
+typedef struct ResampleToken {
+    void *iohub;
+    int pirq;
+} ResampleToken;
+
+typedef struct RemoteIOHubState {
+    PCIDevice d;
+    EventNotifier irqfds[REMOTE_IOHUB_NB_PIRQS];
+    EventNotifier resamplefds[REMOTE_IOHUB_NB_PIRQS];
+    unsigned int irq_level[REMOTE_IOHUB_NB_PIRQS];
+    ResampleToken token[REMOTE_IOHUB_NB_PIRQS];
+    QemuMutex irq_level_lock[REMOTE_IOHUB_NB_PIRQS];
+} RemoteIOHubState;
+
+int remote_iohub_map_irq(PCIDevice *pci_dev, int intx);
+void remote_iohub_set_irq(void *opaque, int pirq, int level);
+void process_set_irqfd_msg(PCIDevice *pci_dev, MPQemuMsg *msg);
+
+void remote_iohub_init(RemoteIOHubState *iohub);
+void remote_iohub_finalize(RemoteIOHubState *iohub);
+
+#endif
diff --git a/include/hw/remote/machine.h b/include/hw/remote/machine.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/remote/machine.h
+++ b/include/hw/remote/machine.h
@@ -XXX,XX +XXX,XX @@
 #include "hw/boards.h"
 #include "hw/pci-host/remote.h"
 #include "io/channel.h"
+#include "hw/remote/iohub.h"
 
 struct RemoteMachineState {
     MachineState parent_obj;
 
     RemotePCIHost *host;
+    RemoteIOHubState iohub;
 };
 
 /* Used to pass to co-routine device and ioc. */
diff --git a/include/hw/remote/mpqemu-link.h b/include/hw/remote/mpqemu-link.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/remote/mpqemu-link.h
+++ b/include/hw/remote/mpqemu-link.h
@@ -XXX,XX +XXX,XX @@ typedef enum {
     MPQEMU_CMD_PCI_CFGREAD,
     MPQEMU_CMD_BAR_WRITE,
     MPQEMU_CMD_BAR_READ,
+    MPQEMU_CMD_SET_IRQFD,
     MPQEMU_CMD_MAX,
 } MPQemuCmd;
 
diff --git a/include/hw/remote/proxy.h b/include/hw/remote/proxy.h
index XXXXXXX..XXXXXXX 100644
--- a/include/hw/remote/proxy.h
+++ b/include/hw/remote/proxy.h
@@ -XXX,XX +XXX,XX @@
 #include "hw/pci/pci.h"
 #include "io/channel.h"
 #include "hw/remote/proxy-memory-listener.h"
+#include "qemu/event_notifier.h"
 
 #define TYPE_PCI_PROXY_DEV "x-pci-proxy-dev"
 OBJECT_DECLARE_SIMPLE_TYPE(PCIProxyDev, PCI_PROXY_DEV)
@@ -XXX,XX +XXX,XX @@ struct PCIProxyDev {
     QIOChannel *ioc;
     Error *migration_blocker;
     ProxyMemoryListener proxy_listener;
+    int virq;
+    EventNotifier intr;
+    EventNotifier resample;
     ProxyMemoryRegion region[PCI_NUM_REGIONS];
 };
 
diff --git a/hw/remote/iohub.c b/hw/remote/iohub.c
new file mode 100644
index XXXXXXX..XXXXXXX
--- /dev/null
+++ b/hw/remote/iohub.c
@@ -XXX,XX +XXX,XX @@
+/*
+ * Remote IO Hub
+ *
+ * Copyright © 2018, 2021 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+
+#include "hw/pci/pci.h"
+#include "hw/pci/pci_ids.h"
+#include "hw/pci/pci_bus.h"
+#include "qemu/thread.h"
+#include "hw/boards.h"
+#include "hw/remote/machine.h"
+#include "hw/remote/iohub.h"
+#include "qemu/main-loop.h"
+
+void remote_iohub_init(RemoteIOHubState *iohub)
+{
+    int pirq;
+
+    memset(&iohub->irqfds, 0, sizeof(iohub->irqfds));
+    memset(&iohub->resamplefds, 0, sizeof(iohub->resamplefds));
+
+    for (pirq = 0; pirq < REMOTE_IOHUB_NB_PIRQS; pirq++) {
+        qemu_mutex_init(&iohub->irq_level_lock[pirq]);
+        iohub->irq_level[pirq] = 0;
+        event_notifier_init_fd(&iohub->irqfds[pirq], -1);
+        event_notifier_init_fd(&iohub->resamplefds[pirq], -1);
+    }
+}
+
+void remote_iohub_finalize(RemoteIOHubState *iohub)
+{
+    int pirq;
+
+    for (pirq = 0; pirq < REMOTE_IOHUB_NB_PIRQS; pirq++) {
+        qemu_set_fd_handler(event_notifier_get_fd(&iohub->resamplefds[pirq]),
+                            NULL, NULL, NULL);
+        event_notifier_cleanup(&iohub->irqfds[pirq]);
+        event_notifier_cleanup(&iohub->resamplefds[pirq]);
+        qemu_mutex_destroy(&iohub->irq_level_lock[pirq]);
+    }
+}
+
+int remote_iohub_map_irq(PCIDevice *pci_dev, int intx)
+{
+    return pci_dev->devfn;
+}
+
+void remote_iohub_set_irq(void *opaque, int pirq, int level)
+{
+    RemoteIOHubState *iohub = opaque;
+
+    assert(pirq >= 0);
+    assert(pirq < PCI_DEVFN_MAX);
+
+    QEMU_LOCK_GUARD(&iohub->irq_level_lock[pirq]);
+
+    if (level) {
+        if (++iohub->irq_level[pirq] == 1) {
+            event_notifier_set(&iohub->irqfds[pirq]);
+        }
+    } else if (iohub->irq_level[pirq] > 0) {
+        iohub->irq_level[pirq]--;
+    }
+}
+
+static void intr_resample_handler(void *opaque)
+{
+    ResampleToken *token = opaque;
+    RemoteIOHubState *iohub = token->iohub;
+    int pirq, s;
+
+    pirq = token->pirq;
+
+    s = event_notifier_test_and_clear(&iohub->resamplefds[pirq]);
+
+    assert(s >= 0);
+
+    QEMU_LOCK_GUARD(&iohub->irq_level_lock[pirq]);
+
+    if (iohub->irq_level[pirq]) {
+        event_notifier_set(&iohub->irqfds[pirq]);
+    }
+}
+
+void process_set_irqfd_msg(PCIDevice *pci_dev, MPQemuMsg *msg)
+{
+    RemoteMachineState *machine = REMOTE_MACHINE(current_machine);
+    RemoteIOHubState *iohub = &machine->iohub;
+    int pirq, intx;
+
+    intx = pci_get_byte(pci_dev->config + PCI_INTERRUPT_PIN) - 1;
+
+    pirq = remote_iohub_map_irq(pci_dev, intx);
+
+    if (event_notifier_get_fd(&iohub->irqfds[pirq]) != -1) {
+        qemu_set_fd_handler(event_notifier_get_fd(&iohub->resamplefds[pirq]),
+                            NULL, NULL, NULL);
+        event_notifier_cleanup(&iohub->irqfds[pirq]);
+        event_notifier_cleanup(&iohub->resamplefds[pirq]);
+        memset(&iohub->token[pirq], 0, sizeof(ResampleToken));
+    }
+
+    event_notifier_init_fd(&iohub->irqfds[pirq], msg->fds[0]);
+    event_notifier_init_fd(&iohub->resamplefds[pirq], msg->fds[1]);
+
+    iohub->token[pirq].iohub = iohub;
+    iohub->token[pirq].pirq = pirq;
+
+    qemu_set_fd_handler(msg->fds[1], intr_resample_handler, NULL,
+                        &iohub->token[pirq]);
+}
diff --git a/hw/remote/machine.c b/hw/remote/machine.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/machine.c
+++ b/hw/remote/machine.c
@@ -XXX,XX +XXX,XX @@
 #include "exec/address-spaces.h"
 #include "exec/memory.h"
 #include "qapi/error.h"
+#include "hw/pci/pci_host.h"
+#include "hw/remote/iohub.h"
 
 static void remote_machine_init(MachineState *machine)
 {
     MemoryRegion *system_memory, *system_io, *pci_memory;
     RemoteMachineState *s = REMOTE_MACHINE(machine);
     RemotePCIHost *rem_host;
+    PCIHostState *pci_host;
 
     system_memory = get_system_memory();
     system_io = get_system_io();
@@ -XXX,XX +XXX,XX @@ static void remote_machine_init(MachineState *machine)
     memory_region_add_subregion_overlap(system_memory, 0x0, pci_memory, -1);
 
     qdev_realize(DEVICE(rem_host), sysbus_get_default(), &error_fatal);
+
+    pci_host = PCI_HOST_BRIDGE(rem_host);
+
+    remote_iohub_init(&s->iohub);
+
+    pci_bus_irqs(pci_host->bus, remote_iohub_set_irq, remote_iohub_map_irq,
+                 &s->iohub, REMOTE_IOHUB_NB_PIRQS);
 }
 
 static void remote_machine_class_init(ObjectClass *oc, void *data)
diff --git a/hw/remote/message.c b/hw/remote/message.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/message.c
+++ b/hw/remote/message.c
@@ -XXX,XX +XXX,XX @@
 #include "hw/pci/pci.h"
 #include "exec/memattrs.h"
 #include "hw/remote/memory.h"
+#include "hw/remote/iohub.h"
 
 static void process_config_write(QIOChannel *ioc, PCIDevice *dev,
                                  MPQemuMsg *msg, Error **errp);
@@ -XXX,XX +XXX,XX @@ void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
         case MPQEMU_CMD_SYNC_SYSMEM:
             remote_sysmem_reconfig(&msg, &local_err);
             break;
+        case MPQEMU_CMD_SET_IRQFD:
+            process_set_irqfd_msg(pci_dev, &msg);
+            break;
         default:
             error_setg(&local_err,
                        "Unknown command (%d) received for device %s"
diff --git a/hw/remote/mpqemu-link.c b/hw/remote/mpqemu-link.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/mpqemu-link.c
+++ b/hw/remote/mpqemu-link.c
@@ -XXX,XX +XXX,XX @@ bool mpqemu_msg_valid(MPQemuMsg *msg)
             return false;
         }
         break;
+    case MPQEMU_CMD_SET_IRQFD:
+        if (msg->size || (msg->num_fds != 2)) {
+            return false;
+        }
+        break;
     default:
         break;
     }
diff --git a/hw/remote/proxy.c b/hw/remote/proxy.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/proxy.c
+++ b/hw/remote/proxy.c
@@ -XXX,XX +XXX,XX @@
 #include "qemu/error-report.h"
 #include "hw/remote/proxy-memory-listener.h"
 #include "qom/object.h"
+#include "qemu/event_notifier.h"
+#include "sysemu/kvm.h"
+#include "util/event_notifier-posix.c"
+
+static void proxy_intx_update(PCIDevice *pci_dev)
+{
+    PCIProxyDev *dev = PCI_PROXY_DEV(pci_dev);
+    PCIINTxRoute route;
+    int pin = pci_get_byte(pci_dev->config + PCI_INTERRUPT_PIN) - 1;
+
+    if (dev->virq != -1) {
+        kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, &dev->intr, dev->virq);
+        dev->virq = -1;
+    }
+
+    route = pci_device_route_intx_to_irq(pci_dev, pin);
+
+    dev->virq = route.irq;
+
+    if (dev->virq != -1) {
+        kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, &dev->intr,
+                                           &dev->resample, dev->virq);
+    }
+}
+
+static void setup_irqfd(PCIProxyDev *dev)
+{
+    PCIDevice *pci_dev = PCI_DEVICE(dev);
+    MPQemuMsg msg;
+    Error *local_err = NULL;
+
+    event_notifier_init(&dev->intr, 0);
+    event_notifier_init(&dev->resample, 0);
+
+    memset(&msg, 0, sizeof(MPQemuMsg));
+    msg.cmd = MPQEMU_CMD_SET_IRQFD;
+    msg.num_fds = 2;
+    msg.fds[0] = event_notifier_get_fd(&dev->intr);
+    msg.fds[1] = event_notifier_get_fd(&dev->resample);
+    msg.size = 0;
+
+    if (!mpqemu_msg_send(&msg, dev->ioc, &local_err)) {
+        error_report_err(local_err);
+    }
+
+    dev->virq = -1;
+
+    proxy_intx_update(pci_dev);
+
+    pci_device_set_intx_routing_notifier(pci_dev, proxy_intx_update);
+}
 
 static void pci_proxy_dev_realize(PCIDevice *device, Error **errp)
 {
@@ -XXX,XX +XXX,XX @@ static void pci_proxy_dev_realize(PCIDevice *device, Error **errp)
     qio_channel_set_blocking(dev->ioc, true, NULL);
 
     proxy_memory_listener_configure(&dev->proxy_listener, dev->ioc);
+
+    setup_irqfd(dev);
 }
 
 static void pci_proxy_dev_exit(PCIDevice *pdev)
@@ -XXX,XX +XXX,XX @@ static void pci_proxy_dev_exit(PCIDevice *pdev)
     error_free(dev->migration_blocker);
 
     proxy_memory_listener_deconfigure(&dev->proxy_listener);
+
+    event_notifier_cleanup(&dev->intr);
+    event_notifier_cleanup(&dev->resample);
 }
 
 static void config_op_send(PCIProxyDev *pdev, uint32_t addr, uint32_t *val,
diff --git a/hw/remote/meson.build b/hw/remote/meson.build
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/meson.build
+++ b/hw/remote/meson.build
@@ -XXX,XX +XXX,XX @@ remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('mpqemu-link.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('message.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('remote-obj.c'))
 remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('proxy.c'))
+remote_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('iohub.c'))
 
 specific_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('memory.c'))
 specific_ss.add(when: 'CONFIG_MULTIPROCESS', if_true: files('proxy-memory-listener.c'))
-- 
2.29.2

From: Jagannathan Raman <jag.raman@oracle.com>

Retrieve PCI configuration info about the remote device and
configure the Proxy PCI object based on the returned information

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 85ee367bbb993aa23699b44cfedd83b4ea6d5221.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/remote/proxy.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)

diff --git a/hw/remote/proxy.c b/hw/remote/proxy.c
index XXXXXXX..XXXXXXX 100644
--- a/hw/remote/proxy.c
+++ b/hw/remote/proxy.c
@@ -XXX,XX +XXX,XX @@
 #include "sysemu/kvm.h"
 #include "util/event_notifier-posix.c"
 
+static void probe_pci_info(PCIDevice *dev, Error **errp);
+
 static void proxy_intx_update(PCIDevice *pci_dev)
 {
     PCIProxyDev *dev = PCI_PROXY_DEV(pci_dev);
@@ -XXX,XX +XXX,XX @@ static void pci_proxy_dev_realize(PCIDevice *device, Error **errp)
 {
     ERRP_GUARD();
     PCIProxyDev *dev = PCI_PROXY_DEV(device);
+    uint8_t *pci_conf = device->config;
     int fd;
 
     if (!dev->fd) {
@@ -XXX,XX +XXX,XX @@ static void pci_proxy_dev_realize(PCIDevice *device, Error **errp)
     qemu_mutex_init(&dev->io_mutex);
     qio_channel_set_blocking(dev->ioc, true, NULL);
 
+    pci_conf[PCI_LATENCY_TIMER] = 0xff;
+    pci_conf[PCI_INTERRUPT_PIN] = 0x01;
+
     proxy_memory_listener_configure(&dev->proxy_listener, dev->ioc);
 
     setup_irqfd(dev);
+
+    probe_pci_info(PCI_DEVICE(dev), errp);
 }
 
 static void pci_proxy_dev_exit(PCIDevice *pdev)
@@ -XXX,XX +XXX,XX @@ const MemoryRegionOps proxy_mr_ops = {
         .max_access_size = 8,
     },
 };
+
+static void probe_pci_info(PCIDevice *dev, Error **errp)
+{
+    PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(dev);
+    uint32_t orig_val, new_val, base_class, val;
+    PCIProxyDev *pdev = PCI_PROXY_DEV(dev);
+    DeviceClass *dc = DEVICE_CLASS(pc);
+    uint8_t type;
+    int i, size;
+
+    config_op_send(pdev, PCI_VENDOR_ID, &val, 2, MPQEMU_CMD_PCI_CFGREAD);
+    pc->vendor_id = (uint16_t)val;
+
+    config_op_send(pdev, PCI_DEVICE_ID, &val, 2, MPQEMU_CMD_PCI_CFGREAD);
+    pc->device_id = (uint16_t)val;
+
+    config_op_send(pdev, PCI_CLASS_DEVICE, &val, 2, MPQEMU_CMD_PCI_CFGREAD);
+    pc->class_id = (uint16_t)val;
+
+    config_op_send(pdev, PCI_SUBSYSTEM_ID, &val, 2, MPQEMU_CMD_PCI_CFGREAD);
+    pc->subsystem_id = (uint16_t)val;
+
+    base_class = pc->class_id >> 4;
+    switch (base_class) {
+    case PCI_BASE_CLASS_BRIDGE:
+        set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
+        break;
+    case PCI_BASE_CLASS_STORAGE:
+        set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
+        break;
+    case PCI_BASE_CLASS_NETWORK:
+        set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
+        break;
+    case PCI_BASE_CLASS_INPUT:
+        set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
+        break;
+    case PCI_BASE_CLASS_DISPLAY:
+        set_bit(DEVICE_CATEGORY_DISPLAY, dc->categories);
+        break;
+    case PCI_BASE_CLASS_PROCESSOR:
+        set_bit(DEVICE_CATEGORY_CPU, dc->categories);
+        break;
+    default:
+        set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+        break;
+    }
+
+    for (i = 0; i < PCI_NUM_REGIONS; i++) {
+        config_op_send(pdev, PCI_BASE_ADDRESS_0 + (4 * i), &orig_val, 4,
+                       MPQEMU_CMD_PCI_CFGREAD);
+        new_val = 0xffffffff;
+        config_op_send(pdev, PCI_BASE_ADDRESS_0 + (4 * i), &new_val, 4,
+                       MPQEMU_CMD_PCI_CFGWRITE);
+        config_op_send(pdev, PCI_BASE_ADDRESS_0 + (4 * i), &new_val, 4,
+                       MPQEMU_CMD_PCI_CFGREAD);
+        size = (~(new_val & 0xFFFFFFF0)) + 1;
+        config_op_send(pdev, PCI_BASE_ADDRESS_0 + (4 * i), &orig_val, 4,
+                       MPQEMU_CMD_PCI_CFGWRITE);
+        type = (new_val & 0x1) ?
+                   PCI_BASE_ADDRESS_SPACE_IO : PCI_BASE_ADDRESS_SPACE_MEMORY;
+
+        if (size) {
+            g_autofree char *name;
+            pdev->region[i].dev = pdev;
+            pdev->region[i].present = true;
+            if (type == PCI_BASE_ADDRESS_SPACE_MEMORY) {
+                pdev->region[i].memory = true;
+            }
+            name = g_strdup_printf("bar-region-%d", i);
+            memory_region_init_io(&pdev->region[i].mr, OBJECT(pdev),
+                                  &proxy_mr_ops, &pdev->region[i],
+                                  name, size);
+            pci_register_bar(dev, i, type, &pdev->region[i].mr);
+        }
+    }
+}
-- 
2.29.2

From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

Perform device reset in the remote process when QEMU performs
device reset. This is required to reset the internal state
(like registers, etc...) of emulated devices

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 7cb220a51f565dc0817bd76e2f540e89c2d2b850.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 include/hw/remote/mpqemu-link.h |  1 +
 hw/remote/message.c             | 22 ++++++++++++++++++++++
 hw/remote/proxy.c               | 19 +++++++++++++++++++
 3 files changed, 42 insertions(+)

From: "Denis V. Lunev" <den@openvz.org>

Original specification says that l1 table size if 64 * l1_size, which
is obviously wrong. The size of the l1 entry is 64 _bits_, not bytes.
Thus 64 is to be replaces with 8 as specification says about bytes.

There is also minor tweak, field name is renamed from l1 to l1_table,
which matches with the later text.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20210128171313.2210947-1-den@openvz.org
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

[Replace the original commit message "docs: fix mistake in dirty bitmap
feature description" as suggested by Eric Blake.
--Stefan]

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 docs/interop/parallels.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/interop/parallels.txt b/docs/interop/parallels.txt
index XXXXXXX..XXXXXXX 100644
--- a/docs/interop/parallels.txt
+++ b/docs/interop/parallels.txt
@@ -XXX,XX +XXX,XX @@ of its data area are:
   28 - 31:    l1_size
               The number of entries in the L1 table of the bitmap.
 
-  variable:   l1 (64 * l1_size bytes)
+  variable:   l1_table (8 * l1_size bytes)
               L1 offset table (in bytes)
 
 A dirty bitmap is stored using a one-level structure for the mapping to host
-- 
2.29.2