[libvirt] [PATCH 2/3] Automatically kill target QEMU if migration aborts abnormally

[Eric Blake]

On 06/23/2011 04:58 AM, Daniel P. Berrange wrote:
> Migration is a multi-step process
> 
>   1. Begin(src)
>   2. Prepare(dst)
>   3. Perform(src)
>   4. Finish(dst)
>   5. Confirm(src)
> 
> At step 2, a QEMU process is lauched in the destination to
> accept the incoming migration. Occasionally the process
> that is controlling the migration workflow aborts, and fails
> to call step 4, Finish. This leaves a QEMU process running
> on the target (albeit with paused CPUs). Unfortunately because
> step 2 actives a job on the QEMU process, it is unkillable by
> normal means.
> 
> By registering the VM for autokill against the src virConnectPtr
> in step 2, we can ensure that the guest is forcefully killed off
> if the connection is closed without step 4 being invoked
> 
> * src/qemu/qemu_migration.c: Register autokill in PrepareDirect
>   and PrepareTunnel. Unregister autokill on successful run
>   of Finish
> * src/qemu/qemu_process.c: Unregister autokill when stopping a
>   process
> ---
>  src/qemu/qemu_migration.c |    7 +++++--
>  1 files changed, 5 insertions(+), 2 deletions(-)

See comments on 0/3 about whether this patch is complete or whether we
need more restrictions on migration when autokill is active.  But for
what you have here:

ACK with nits.

> @@ -2549,6 +2549,9 @@ qemuMigrationFinish(struct qemud_driver *driver,
>              VIR_WARN("Failed to save status on vm %s", vm->def->name);
>              goto endjob;
>          }
> +
> +        /* Guest is sucessfully running, so cancel previous autokill */

s/sucessfully/successfully/

> +        qemuProcessAutokillRemove(driver, vm);
>      } else {
>          qemuProcessStop(driver, vm, 1, VIR_DOMAIN_SHUTOFF_FAILED);
>          qemuAuditDomainStop(vm, "failed");

-- 
Eric Blake   eblake at redhat.com    +1-801-349-2682
Libvirt virtualization library http://libvirt.org

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 619 bytes
Desc: OpenPGP digital signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20110623/179adb0d/attachment-0001.sig>