[libvirt PATCH 69/80] qemu: Implement VIR_MIGRATE_POSTCOPY_RESUME for Finish phase

[Peter Krempa]

On Tue, May 10, 2022 at 17:21:30 +0200, Jiri Denemark wrote:
> Everything was already done in the normal Finish phase and vCPUs are
> running. We just need to wait for all remaining data to be transferred.
> 
> Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
> ---
>  src/qemu/qemu_migration.c | 46 ++++++++++++++++++++++++++++++++++-----
>  1 file changed, 40 insertions(+), 6 deletions(-)
> 
> diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
> index a8481f7515..430dfb1abb 100644
> --- a/src/qemu/qemu_migration.c
> +++ b/src/qemu/qemu_migration.c
> @@ -6600,6 +6600,22 @@ qemuMigrationDstFinishFresh(virQEMUDriver *driver,
>  }
>  
>  
> +static int
> +qemuMigrationDstFinishResume(virQEMUDriver *driver,
> +                             virDomainObj *vm)
> +{
> +    VIR_DEBUG("vm=%p", vm);
> +
> +    if (qemuMigrationDstWaitForCompletion(driver, vm,
> +                                          VIR_ASYNC_JOB_MIGRATION_IN,
> +                                          false) < 0) {
> +        return -1;
> +    }

As I mentioned in another reply, IMO it would be useful to allow
adoption of a unattended running migration precisely for this case, so
that mgmt apps don't have to encode more logic to wait for events if
migration was actually running fine.

> +
> +    return 0;
> +}
> +
> +
>  static virDomainPtr
>  qemuMigrationDstFinishActive(virQEMUDriver *driver,
>                               virConnectPtr dconn,
> @@ -6647,8 +6663,14 @@ qemuMigrationDstFinishActive(virQEMUDriver *driver,
>          goto error;
>      }
>  
> -    rc = qemuMigrationDstFinishFresh(driver, vm, mig, flags, v3proto,
> -                                     timeReceived, &doKill, &inPostCopy);
> +    if (flags & VIR_MIGRATE_POSTCOPY_RESUME) {
> +        rc = qemuMigrationDstFinishResume(driver, vm);
> +        inPostCopy = true;
> +    } else {
> +        rc = qemuMigrationDstFinishFresh(driver, vm, mig, flags, v3proto,
> +                                         timeReceived, &doKill, &inPostCopy);
> +    }
> +
>      if (rc < 0 ||
>          !(dom = virGetDomain(dconn, vm->def->name, vm->def->uuid, vm->def->id)))
>          goto error;
> @@ -6719,6 +6741,8 @@ qemuMigrationDstFinish(virQEMUDriver *driver,
>      qemuDomainObjPrivate *priv = vm->privateData;
>      unsigned short port;
>      unsigned long long timeReceived = 0;
> +    int phase = v3proto ? QEMU_MIGRATION_PHASE_FINISH3
> +                        : QEMU_MIGRATION_PHASE_FINISH2;


Avoid use of ?

>  
>      VIR_DEBUG("driver=%p, dconn=%p, vm=%p, cookiein=%s, cookieinlen=%d, "
>                "cookieout=%p, cookieoutlen=%p, flags=0x%lx, retcode=%d",

Reviewed-by: Peter Krempa <pkrempa at redhat.com>