Re: [Qemu-devel] [PATCH 2/3] move vm stop/start to migrate_set_state

[Anthony Liguori <anthony@codemonkey.ws>]

Paolo Bonzini wrote:
> On 07/09/2009 03:53 PM, Anthony Liguori wrote:
>> Paolo Bonzini wrote:
>>> On 07/09/2009 03:45 PM, Anthony Liguori wrote:
>>>> How does the disk become full during the final stage? The guest isn't
>>>> running.
>>>
>>> The host disk can become full and cause a "migrate exec" to fail. Or
>>> for network migration migration, you could have the connection drop
>>> exactly during the final stage. In this case, the VM would be
>>> unconditionally restarted.
>>
>> Because migration failed. Is that not the desired behavior? It seems
>> like it is to me.
>
> By "unconditionally" I meant "even if the VM used to be paused".

Oh, that's definitely a bug.  But that's an easy fix too:

diff --git a/migration.c b/migration.c
index 190b37e..e6c8b16 100644
--- a/migration.c
+++ b/migration.c
@@ -261,12 +261,16 @@ void migrate_fd_put_ready(void *opaque)
     dprintf("iterate\n");
     if (qemu_savevm_state_iterate(s->file) == 1) {
         int state;
+        int old_vm_running = vm_running;
+
         dprintf("done iterating\n");
         vm_stop(0);
 
         bdrv_flush_all();
         if ((qemu_savevm_state_complete(s->file)) < 0) {
-            vm_start();
+            if (old_vm_running) {
+                vm_start();
+            }
             state = MIG_STATE_ERROR;
         } else {
             state = MIG_STATE_COMPLETED;

Regards,

Anthony Liguori

> Paolo