cpu-exec.c | 14 +++--- cpus.c | 111 +++++++++++++++++++++++++++++++++------------- include/qemu/timer.h | 1 + include/qom/cpu.h | 1 + replay/replay-internal.c | 4 ++ replay/replay.c | 4 ++ scripts/qemugdb/mtree.py | 12 ++++- target/i386/misc_helper.c | 3 ++ 8 files changed, 110 insertions(+), 40 deletions(-)
The following changes since commit 5fe2339e6b09da7d6f48b9bef0f1a7360392b489:
Merge remote-tracking branch 'remotes/awilliam/tags/vfio-updates-20170406.0' into staging (2017-04-07 10:29:56 +0100)
are available in the git repository at:
https://github.com/stsquad/qemu.git tags/pull-mttcg-fixups-for-rc2-100417-1
for you to fetch changes up to 982263ce714ffcc4c7c41a7b255bd29e093912fe:
replay: assert time only goes forward (2017-04-10 10:23:38 +0100)
----------------------------------------------------------------
Final icount and misc MTTCG fixes for 2.9
Minor differences from:
Message-Id: <20170405132503.32125-1-alex.bennee@linaro.org>
- dropped new feature patches
- last minute typo fix from Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
----------------------------------------------------------------
Alex Bennée (10):
scripts/qemugdb/mtree.py: fix up mtree dump
target/i386/misc_helper: wrap BQL around another IRQ generator
cpus: remove icount handling from qemu_tcg_cpu_thread_fn
cpus: check cpu->running in cpu_get_icount_raw()
cpus: move icount preparation out of tcg_exec_cpu
cpus: don't credit executed instructions before they have run
cpus: introduce cpu_update_icount helper
cpu-exec: update icount after each TB_EXIT
cpus: call cpu_update_icount on read
replay: assert time only goes forward
Nikunj A Dadhania (1):
cpus: fix wrong define name
cpu-exec.c | 14 +++---
cpus.c | 111 +++++++++++++++++++++++++++++++++-------------
include/qemu/timer.h | 1 +
include/qom/cpu.h | 1 +
replay/replay-internal.c | 4 ++
replay/replay.c | 4 ++
scripts/qemugdb/mtree.py | 12 ++++-
target/i386/misc_helper.c | 3 ++
8 files changed, 110 insertions(+), 40 deletions(-)
--
2.11.0
Since QEMU has been able to build with native Int128 support this was
broken as it attempts to fish values out of the non-existent
structure. Also the alias print was trying to make a %x out of
gdb.ValueType directly which didn't seem to work.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
diff --git a/scripts/qemugdb/mtree.py b/scripts/qemugdb/mtree.py
index cc8131c2e7..e6791b7885 100644
--- a/scripts/qemugdb/mtree.py
+++ b/scripts/qemugdb/mtree.py
@@ -21,7 +21,15 @@ def isnull(ptr):
return ptr == gdb.Value(0).cast(ptr.type)
def int128(p):
- return int(p['lo']) + (int(p['hi']) << 64)
+ '''Read an Int128 type to a python integer.
+
+ QEMU can be built with native Int128 support so we need to detect
+ if the value is a structure or the native type.
+ '''
+ if p.type.code == gdb.TYPE_CODE_STRUCT:
+ return int(p['lo']) + (int(p['hi']) << 64)
+ else:
+ return int(("%s" % p), 16)
class MtreeCommand(gdb.Command):
'''Display the memory tree hierarchy'''
@@ -69,7 +77,7 @@ class MtreeCommand(gdb.Command):
gdb.write('%s alias: %s@%016x (@ %s)\n' %
(' ' * level,
alias['name'].string(),
- ptr['alias_offset'],
+ int(ptr['alias_offset']),
alias,
),
gdb.STDOUT)
--
2.11.0
From: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
While the configure script generates TARGET_SUPPORTS_MTTCG define, one
of the define is cpus.c is checking wrong name: TARGET_SUPPORT_MTTCG
Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
diff --git a/cpus.c b/cpus.c
index 68fdbc40b9..58d90aa2b9 100644
--- a/cpus.c
+++ b/cpus.c
@@ -202,7 +202,7 @@ void qemu_tcg_configure(QemuOpts *opts, Error **errp)
} else if (use_icount) {
error_setg(errp, "No MTTCG when icount is enabled");
} else {
-#ifndef TARGET_SUPPORT_MTTCG
+#ifndef TARGET_SUPPORTS_MTTCG
error_report("Guest not yet converted to MTTCG - "
"you may get unexpected results");
#endif
--
2.11.0
Anything that calls into HW emulation must be protected by the BQL.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Acked-by: Eduardo Habkost <ehabkost@redhat.com>
diff --git a/target/i386/misc_helper.c b/target/i386/misc_helper.c
index ca2ea09f54..628f64aad5 100644
--- a/target/i386/misc_helper.c
+++ b/target/i386/misc_helper.c
@@ -18,6 +18,7 @@
*/
#include "qemu/osdep.h"
+#include "qemu/main-loop.h"
#include "cpu.h"
#include "exec/helper-proto.h"
#include "exec/exec-all.h"
@@ -156,7 +157,9 @@ void helper_write_crN(CPUX86State *env, int reg, target_ulong t0)
break;
case 8:
if (!(env->hflags2 & HF2_VINTR_MASK)) {
+ qemu_mutex_lock_iothread();
cpu_set_apic_tpr(x86_env_get_cpu(env)->apic_state, t0);
+ qemu_mutex_unlock_iothread();
}
env->v_tpr = t0 & 0x0f;
break;
--
2.11.0
We should never be running in multi-threaded mode with icount enabled.
There is no point calling handle_icount_deadline here so remove it and
assert !use_icount.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
diff --git a/cpus.c b/cpus.c
index 58d90aa2b9..fc0ddc8793 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1392,6 +1392,8 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
{
CPUState *cpu = arg;
+ g_assert(!use_icount);
+
rcu_register_thread();
qemu_mutex_lock_iothread();
@@ -1434,8 +1436,6 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
}
}
- handle_icount_deadline();
-
atomic_mb_set(&cpu->exit_request, 0);
qemu_tcg_wait_io_event(cpu);
}
--
2.11.0
The lifetime of current_cpu is now the lifetime of the vCPU thread.
However get_icount_raw() can apply a fudge factor if called while code
is running to take into account the current executed instruction
count.
To ensure this is always the case we also check cpu->running.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
diff --git a/cpus.c b/cpus.c
index fc0ddc8793..7ec6473c02 100644
--- a/cpus.c
+++ b/cpus.c
@@ -229,7 +229,7 @@ int64_t cpu_get_icount_raw(void)
CPUState *cpu = current_cpu;
icount = timers_state.qemu_icount;
- if (cpu) {
+ if (cpu && cpu->running) {
if (!cpu->can_do_io) {
fprintf(stderr, "Bad icount read\n");
exit(1);
--
2.11.0
As icount is only supported for single-threaded execution due to the
requirement for determinism let's remove it from the common
tcg_exec_cpu path.
Also remove the additional fiddling which shouldn't be required as the
icount counters should all be rectified as you enter the loop.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
diff --git a/cpus.c b/cpus.c
index 7ec6473c02..6034b104c3 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1179,47 +1179,64 @@ static void handle_icount_deadline(void)
}
}
-static int tcg_cpu_exec(CPUState *cpu)
+static void prepare_icount_for_run(CPUState *cpu)
{
- int ret;
-#ifdef CONFIG_PROFILER
- int64_t ti;
-#endif
-
-#ifdef CONFIG_PROFILER
- ti = profile_getclock();
-#endif
if (use_icount) {
int64_t count;
int decr;
- timers_state.qemu_icount -= (cpu->icount_decr.u16.low
- + cpu->icount_extra);
- cpu->icount_decr.u16.low = 0;
- cpu->icount_extra = 0;
+
+ /* These should always be cleared by process_icount_data after
+ * each vCPU execution. However u16.high can be raised
+ * asynchronously by cpu_exit/cpu_interrupt/tcg_handle_interrupt
+ */
+ g_assert(cpu->icount_decr.u16.low == 0);
+ g_assert(cpu->icount_extra == 0);
+
+
count = tcg_get_icount_limit();
+
timers_state.qemu_icount += count;
decr = (count > 0xffff) ? 0xffff : count;
count -= decr;
cpu->icount_decr.u16.low = decr;
cpu->icount_extra = count;
}
- qemu_mutex_unlock_iothread();
- cpu_exec_start(cpu);
- ret = cpu_exec(cpu);
- cpu_exec_end(cpu);
- qemu_mutex_lock_iothread();
-#ifdef CONFIG_PROFILER
- tcg_time += profile_getclock() - ti;
-#endif
+}
+
+static void process_icount_data(CPUState *cpu)
+{
if (use_icount) {
/* Fold pending instructions back into the
instruction counter, and clear the interrupt flag. */
timers_state.qemu_icount -= (cpu->icount_decr.u16.low
+ cpu->icount_extra);
- cpu->icount_decr.u32 = 0;
+
+ /* Reset the counters */
+ cpu->icount_decr.u16.low = 0;
cpu->icount_extra = 0;
replay_account_executed_instructions();
}
+}
+
+
+static int tcg_cpu_exec(CPUState *cpu)
+{
+ int ret;
+#ifdef CONFIG_PROFILER
+ int64_t ti;
+#endif
+
+#ifdef CONFIG_PROFILER
+ ti = profile_getclock();
+#endif
+ qemu_mutex_unlock_iothread();
+ cpu_exec_start(cpu);
+ ret = cpu_exec(cpu);
+ cpu_exec_end(cpu);
+ qemu_mutex_lock_iothread();
+#ifdef CONFIG_PROFILER
+ tcg_time += profile_getclock() - ti;
+#endif
return ret;
}
@@ -1306,7 +1323,13 @@ static void *qemu_tcg_rr_cpu_thread_fn(void *arg)
if (cpu_can_run(cpu)) {
int r;
+
+ prepare_icount_for_run(cpu);
+
r = tcg_cpu_exec(cpu);
+
+ process_icount_data(cpu);
+
if (r == EXCP_DEBUG) {
cpu_handle_guest_debug(cpu);
break;
--
2.11.0
This ensures each time the vCPU thread reads the icount we update the
master timer_state.qemu_icount field. This way as long as updates are
in BQL protected sections (which they should be) the main-loop can
never come to update the log and find time has gone backwards.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
diff --git a/cpus.c b/cpus.c
index 9c8bd2c991..740b8dc3f8 100644
--- a/cpus.c
+++ b/cpus.c
@@ -253,19 +253,21 @@ void cpu_update_icount(CPUState *cpu)
int64_t cpu_get_icount_raw(void)
{
- int64_t icount;
CPUState *cpu = current_cpu;
- icount = atomic_read(&timers_state.qemu_icount);
if (cpu && cpu->running) {
if (!cpu->can_do_io) {
fprintf(stderr, "Bad icount read\n");
exit(1);
}
/* Take into account what has run */
- icount += cpu_get_icount_executed(cpu);
+ cpu_update_icount(cpu);
}
- return icount;
+#ifdef CONFIG_ATOMIC64
+ return atomic_read__nocheck(&timers_state.qemu_icount);
+#else /* FIXME: we need 64bit atomics to do this safely */
+ return timers_state.qemu_icount;
+#endif
}
/* Return the virtual CPU time, based on the instruction counter. */
--
2.11.0
On 10 April 2017 at 13:55, Alex Bennée <alex.bennee@linaro.org> wrote: > The following changes since commit 5fe2339e6b09da7d6f48b9bef0f1a7360392b489: > > Merge remote-tracking branch 'remotes/awilliam/tags/vfio-updates-20170406.0' into staging (2017-04-07 10:29:56 +0100) > > are available in the git repository at: > > https://github.com/stsquad/qemu.git tags/pull-mttcg-fixups-for-rc2-100417-1 > > for you to fetch changes up to 982263ce714ffcc4c7c41a7b255bd29e093912fe: > > replay: assert time only goes forward (2017-04-10 10:23:38 +0100) > > ---------------------------------------------------------------- > Final icount and misc MTTCG fixes for 2.9 > > Minor differences from: > Message-Id: <20170405132503.32125-1-alex.bennee@linaro.org> > > - dropped new feature patches > - last minute typo fix from Nikunj A Dadhania <nikunj@linux.vnet.ibm.com> > > ---------------------------------------------------------------- Applied, thanks. -- PMM
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