[Qemu-devel] [PATCH RFC 2/3] migration: Fix global state with Xen.

[Anthony PERARD <anthony.perard@citrix.com>]

From: Anthony PERARD <anthony.perard@gmail.com>

When doing migration via the QMP command xen_save_devices_state, the
current runstate is not store into the global state section. Also the
current runstate is not the one we want on the receiver side.

During migration, the Xen toolstack paused QEMU before save the devices
state. Also, the toolstack expect QEMU to autostart when the migration is
finished.
So this patch store "running" as it's current runstate.

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
---
 include/migration/migration.h | 1 +
 migration/migration.c         | 7 +++++++
 migration/savevm.c            | 1 +
 3 files changed, 9 insertions(+)

diff --git a/include/migration/migration.h b/include/migration/migration.h
index a2f8ed0..8334621 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -203,4 +203,5 @@ void register_global_state(void);
 void global_state_set_optional(void);
 void savevm_skip_configuration(void);
 int global_state_store(void);
+void global_state_store_running(void);
 #endif
diff --git a/migration/migration.c b/migration/migration.c
index fd4f99b..175a397 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -122,6 +122,13 @@ int global_state_store(void)
     return 0;
 }
 
+void global_state_store_running(void)
+{
+    const char *state = RunState_lookup[RUN_STATE_RUNNING];
+    memcpy((char *)global_state.runstate,
+           state, sizeof(global_state.runstate));
+}
+
 static bool global_state_received(void)
 {
     return global_state.received;
diff --git a/migration/savevm.c b/migration/savevm.c
index 81dbe58..6071215 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1394,6 +1394,7 @@ void qmp_xen_save_devices_state(const char *filename, Error **errp)
 
     saved_vm_running = runstate_is_running();
     vm_stop(RUN_STATE_SAVE_VM);
+    global_state_store_running();
 
     f = qemu_fopen(filename, "wb");
     if (!f) {
-- 
Anthony PERARD