[PATCH v2 5/7] system/physmem: Notify RAMBlock migratable and idstr changes

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 <[email protected]>
---
 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