[Qemu-devel] [PATCH 1/1] migration: fix inability to save VM after snapshot

[Qemu-devel] [PATCH 1/1] migration: fix inability to save VM after snapshot

[Denis V. Lunev]

The following sequence of operations fails:
    virsh start vm
    virsh snapshot-create vm
    virshh save vm --file file
with the following error
    error: Failed to save domain vm to file
    error: internal error: unable to execute QEMU command 'migrate':
    There's a migration process in progress

The problem is that qemu_savevm_state() calls migrate_init() which sets
migration state to MIGRATION_STATUS_SETUP and never cleaned it up.
This patch do the job.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Juan Quintela <quintela@redhat.com>
CC: Amit Shah <amit.shah@redhat.com>
---
 migration/savevm.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/migration/savevm.c b/migration/savevm.c
index 6c21231..749df1e 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1149,10 +1149,12 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
         .shared = 0
     };
     MigrationState *ms = migrate_init(&params);
+    MigrationStatus status;
     ms->to_dst_file = f;
 
     if (migration_is_blocked(errp)) {
-        return -EINVAL;
+        ret = -EINVAL;
+        goto done;
     }
 
     qemu_mutex_unlock_iothread();
@@ -1175,6 +1177,14 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
     if (ret != 0) {
         error_setg_errno(errp, -ret, "Error while writing VM state");
     }
+
+done:
+    if (ret != 0) {
+        status = MIGRATION_STATUS_FAILED;
+    } else {
+        status = MIGRATION_STATUS_COMPLETED;
+    }
+    migrate_set_state(&ms->state, MIGRATION_STATUS_SETUP, status);
     return ret;
 }
 
-- 
2.5.0

Re: [Qemu-devel] [PATCH 1/1] migration: fix inability to save VM after snapshot

[Dr. David Alan Gilbert]

* Denis V. Lunev (den@openvz.org) wrote:
> The following sequence of operations fails:
>     virsh start vm
>     virsh snapshot-create vm
>     virshh save vm --file file
> with the following error
>     error: Failed to save domain vm to file
>     error: internal error: unable to execute QEMU command 'migrate':
>     There's a migration process in progress
> 
> The problem is that qemu_savevm_state() calls migrate_init() which sets
> migration state to MIGRATION_STATUS_SETUP and never cleaned it up.
> This patch do the job.
> 
> Signed-off-by: Denis V. Lunev <den@openvz.org>
> CC: Juan Quintela <quintela@redhat.com>
> CC: Amit Shah <amit.shah@redhat.com>


Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  migration/savevm.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 6c21231..749df1e 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1149,10 +1149,12 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
>          .shared = 0
>      };
>      MigrationState *ms = migrate_init(&params);
> +    MigrationStatus status;
>      ms->to_dst_file = f;
>  
>      if (migration_is_blocked(errp)) {
> -        return -EINVAL;
> +        ret = -EINVAL;
> +        goto done;
>      }
>  
>      qemu_mutex_unlock_iothread();
> @@ -1175,6 +1177,14 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp)
>      if (ret != 0) {
>          error_setg_errno(errp, -ret, "Error while writing VM state");
>      }
> +
> +done:
> +    if (ret != 0) {
> +        status = MIGRATION_STATUS_FAILED;
> +    } else {
> +        status = MIGRATION_STATUS_COMPLETED;
> +    }
> +    migrate_set_state(&ms->state, MIGRATION_STATUS_SETUP, status);
>      return ret;
>  }
>  
> -- 
> 2.5.0
> 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK