[libvirt] [PATCH 2/7] qemu: Properly update completed migration stats

[Jiri Denemark]

On Tue, Feb 23, 2016 at 16:41:41 +0100, Jiri Denemark wrote:
> We should not overwrite all migration statistics on the source with the
> numbers sent by the destination since the source may have an updated
> view in some cases (such as post-copy migration). It's safer to update
> just the timing info we need to get from the destination and be prepared
> for the future. And we should only do all this after a successful
> migration.
> 
> Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
> ---
>  src/qemu/qemu_migration.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
> index 97e98bb..e6895df 100644
> --- a/src/qemu/qemu_migration.c
> +++ b/src/qemu/qemu_migration.c
...
> @@ -3884,12 +3886,18 @@ qemuMigrationConfirmPhase(virQEMUDriverPtr driver,
>                                         QEMU_MIGRATION_COOKIE_STATS)))
>          goto cleanup;
>  
> -    /* Update total times with the values sent by the destination daemon */
> -    if (mig->jobInfo) {
> -        qemuDomainObjPrivatePtr priv = vm->privateData;
> +    /* Update times with the values sent by the destination daemon */
> +    if (retcode == 0)
> +        jobInfo = priv->job.completed;
> +    else
>          VIR_FREE(priv->job.completed);
> -        priv->job.completed = mig->jobInfo;
> -        mig->jobInfo = NULL;
> +    if (mig->jobInfo && jobInfo) {
> +        jobInfo->type = mig->jobInfo->type;
> +        qemuDomainJobInfoUpdateTime(jobInfo);
> +        jobInfo->timeDeltaSet = mig->jobInfo->timeDeltaSet;
> +        jobInfo->timeDelta = mig->jobInfo->timeDelta;
> +        jobInfo->stats.downtime_set = mig->jobInfo->stats.downtime_set;
> +        jobInfo->stats.downtime = mig->jobInfo->stats.downtime;
>      }
>  
>      if (flags & VIR_MIGRATE_OFFLINE)

Consider the following patch squashed in:

diff --git i/src/qemu/qemu_migration.c w/src/qemu/qemu_migration.c
index e6895df..d587bb6 100644
--- i/src/qemu/qemu_migration.c
+++ w/src/qemu/qemu_migration.c
@@ -3886,13 +3886,13 @@ qemuMigrationConfirmPhase(virQEMUDriverPtr driver,
                                        QEMU_MIGRATION_COOKIE_STATS)))
         goto cleanup;
 
-    /* Update times with the values sent by the destination daemon */
     if (retcode == 0)
         jobInfo = priv->job.completed;
     else
         VIR_FREE(priv->job.completed);
+
+    /* Update times with the values sent by the destination daemon */
     if (mig->jobInfo && jobInfo) {
-        jobInfo->type = mig->jobInfo->type;
         qemuDomainJobInfoUpdateTime(jobInfo);
         jobInfo->timeDeltaSet = mig->jobInfo->timeDeltaSet;
         jobInfo->timeDelta = mig->jobInfo->timeDelta;