The RAM migration code assumes that the set of migratable RAMBlocks and
their idstr values do not change while migration is running. Add
RAMBlockNotifier callbacks for RAM_MIGRATABLE flag and idstr changes so
migration can detect attempts to make such changes at runtime and abort
with a clear error.

Signed-off-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
---
 include/system/ramlist.h |  6 ++++++
 hw/core/numa.c           | 36 ++++++++++++++++++++++++++++++++++++
 system/physmem.c         |  9 +++++++++
 3 files changed, 51 insertions(+)

diff --git a/include/system/ramlist.h b/include/system/ramlist.h
index 32157cc84305..e96de5573eed 100644
--- a/include/system/ramlist.h
+++ b/include/system/ramlist.h
@@ -66,6 +66,9 @@ struct RAMBlockNotifier {
                             void *host, size_t size, size_t max_size);
     void (*ram_block_removed)(RAMBlockNotifier *n, const RAMBlock *rb,
                               void *host, size_t size, size_t max_size);
+    void (*ram_block_set_migratable)(RAMBlockNotifier *n, const RAMBlock *rb);
+    void (*ram_block_unset_migratable)(RAMBlockNotifier *n, const RAMBlock *rb);
+    void (*ram_block_set_idstr)(RAMBlockNotifier *n, const RAMBlock *rb);
     void (*ram_block_resized)(RAMBlockNotifier *n, RAMBlock *rb,
                               size_t new_size);
     QLIST_ENTRY(RAMBlockNotifier) next;
@@ -81,6 +84,9 @@ void ram_block_notify_add(const RAMBlock *rb,
                           void *host, size_t size, size_t max_size);
 void ram_block_notify_remove(const RAMBlock *rb,
                              void *host, size_t size, size_t max_size);
+void ram_block_notify_set_migratable(const RAMBlock *rb);
+void ram_block_notify_unset_migratable(const RAMBlock *rb);
+void ram_block_notify_set_idstr(const RAMBlock *rb);
 void ram_block_notify_resize(RAMBlock *rb, size_t new_size);
 
 GString *ram_block_format(void);
diff --git a/hw/core/numa.c b/hw/core/numa.c
index 40acb98bdd0b..0685cd1c6ccc 100644
--- a/hw/core/numa.c
+++ b/hw/core/numa.c
@@ -887,6 +887,42 @@ void ram_block_notify_remove(const RAMBlock *rb,
     }
 }
 
+void ram_block_notify_set_migratable(const RAMBlock *rb)
+{
+    RAMBlockNotifier *notifier;
+    RAMBlockNotifier *next;
+
+    QLIST_FOREACH_SAFE(notifier, &ram_list.ramblock_notifiers, next, next) {
+        if (notifier->ram_block_set_migratable) {
+            notifier->ram_block_set_migratable(notifier, rb);
+        }
+    }
+}
+
+void ram_block_notify_unset_migratable(const RAMBlock *rb)
+{
+    RAMBlockNotifier *notifier;
+    RAMBlockNotifier *next;
+
+    QLIST_FOREACH_SAFE(notifier, &ram_list.ramblock_notifiers, next, next) {
+        if (notifier->ram_block_unset_migratable) {
+            notifier->ram_block_unset_migratable(notifier, rb);
+        }
+    }
+}
+
+void ram_block_notify_set_idstr(const RAMBlock *rb)
+{
+    RAMBlockNotifier *notifier;
+    RAMBlockNotifier *next;
+
+    QLIST_FOREACH_SAFE(notifier, &ram_list.ramblock_notifiers, next, next) {
+        if (notifier->ram_block_set_idstr) {
+            notifier->ram_block_set_idstr(notifier, rb);
+        }
+    }
+}
+
 void ram_block_notify_resize(RAMBlock *rb, size_t new_size)
 {
     RAMBlockNotifier *notifier;
diff --git a/system/physmem.c b/system/physmem.c
index 1427949b72cd..e8ec6a152af4 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -1911,11 +1911,17 @@ bool qemu_ram_is_migratable(const RAMBlock *rb)
 
 void qemu_ram_set_migratable(RAMBlock *rb)
 {
+    /* Notify before modifying the ram block. */
+    ram_block_notify_set_migratable(rb);
+
     rb->flags |= RAM_MIGRATABLE;
 }
 
 void qemu_ram_unset_migratable(RAMBlock *rb)
 {
+    /* Notify before modifying the ram block. */
+    ram_block_notify_unset_migratable(rb);
+
     rb->flags &= ~RAM_MIGRATABLE;
 }
 
@@ -1937,6 +1943,9 @@ void qemu_ram_set_idstr(RAMBlock *new_block, const char *name, DeviceState *dev)
     assert(new_block);
     assert(!new_block->idstr[0]);
 
+    /* Notify before modifying the ram block. */
+    ram_block_notify_set_idstr(new_block);
+
     if (dev) {
         char *id = qdev_get_dev_path(dev);
         if (id) {

-- 
2.54.0