[libvirt] [PATCH v2 7/7] qemu: Use qemuProcessLaunch in migration Prepare phase

[Pavel Hrdina]

On Thu, Nov 19, 2015 at 01:09:21PM +0100, Jiri Denemark wrote:
> Using qemuProcess{Init,Launch,FinishStartup} allows us to run
> pre-migration commands on destination before asking QEMU to wait for
> incoming migration data.
> 
> Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
> ---
>  src/qemu/qemu_migration.c | 68 ++++++++++++++++++++++++++++++-----------------
>  1 file changed, 44 insertions(+), 24 deletions(-)
> 
> diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
> index b6525df..fe9b1ff 100644
> --- a/src/qemu/qemu_migration.c
> +++ b/src/qemu/qemu_migration.c
> @@ -3291,14 +3291,16 @@ qemuMigrationPrepareCleanup(virQEMUDriverPtr driver,
>      qemuDomainObjDiscardAsyncJob(driver, vm);
>  }
>  
> -static char *
> +static qemuProcessIncomingDefPtr
>  qemuMigrationPrepareIncoming(virDomainObjPtr vm,
>                               bool tunnel,
>                               const char *protocol,
>                               const char *listenAddress,
> -                             unsigned short port)
> +                             unsigned short port,
> +                             int fd)
>  {
>      qemuDomainObjPrivatePtr priv = vm->privateData;
> +    qemuProcessIncomingDefPtr inc = NULL;
>      char *migrateFrom = NULL;
>  
>      if (tunnel) {
> @@ -3361,8 +3363,11 @@ qemuMigrationPrepareIncoming(virDomainObjPtr vm,
>              goto cleanup;
>      }
>  
> +    inc = qemuProcessIncomingDefNew(priv->qemuCaps, migrateFrom, fd, NULL);
> +
>   cleanup:
> -    return migrateFrom;
> +    VIR_FREE(migrateFrom);
> +    return inc;
>  }
>  
>  static int
> @@ -3393,8 +3398,11 @@ qemuMigrationPrepareAny(virQEMUDriverPtr driver,
>      char *xmlout = NULL;
>      unsigned int cookieFlags;
>      virCapsPtr caps = NULL;
> -    char *migrateFrom = NULL;
> +    qemuProcessIncomingDefPtr incoming = NULL;
>      bool taint_hook = false;
> +    bool stopProcess = false;
> +    bool relabel = false;
> +    int rv;
>  
>      virNWFilterReadLockFilterUpdates();
>  
> @@ -3528,28 +3536,29 @@ qemuMigrationPrepareAny(virQEMUDriverPtr driver,
>          goto stopjob;
>      }
>  
> -    virObjectUnref(priv->qemuCaps);
> -    priv->qemuCaps = virQEMUCapsCacheLookupCopy(driver->qemuCapsCache,
> -                                                vm->def->emulator,
> -                                                vm->def->os.machine);
> -    if (!priv->qemuCaps)
> +    if ((rv = qemuProcessInit(driver, vm, true)) < 0) {
> +        if (rv == -1)
> +            stopProcess = true;
>          goto stopjob;
> +    }
> +    stopProcess = true;

With the changes in 1/7 and 5/7 this could be simple:

if (qemuProcessInit(driver, vm, true) < 0)
    goto endjob/endmigjob/stobjob;

And every other goto will jump to 'stop' to make sure that the qemuProcess is
stopped too.

>  
> -    if (!(migrateFrom = qemuMigrationPrepareIncoming(vm, tunnel, protocol,
> -                                                     listenAddress, port)))
> +    if (!(incoming = qemuMigrationPrepareIncoming(vm, tunnel, protocol,
> +                                                  listenAddress, port,
> +                                                  dataFD[0])))
>          goto stopjob;
> +    dataFD[0] = -1; /* the FD is now owned by incoming */
>  
> -    /* Start the QEMU daemon, with the same command-line arguments plus
> -     * -incoming $migrateFrom
> -     */
> -    if (qemuProcessStart(dconn, driver, vm, QEMU_ASYNC_JOB_MIGRATION_IN,
> -                         migrateFrom, dataFD[0], NULL, NULL,
> -                         VIR_NETDEV_VPORT_PROFILE_OP_MIGRATE_IN_START,
> -                         VIR_QEMU_PROCESS_START_PAUSED |
> -                         VIR_QEMU_PROCESS_START_AUTODESTROY) < 0) {
> -        virDomainAuditStart(vm, "migrated", false);
> +    rv = qemuProcessLaunch(dconn, driver, vm, QEMU_ASYNC_JOB_MIGRATION_IN,
> +                           incoming, NULL,
> +                           VIR_NETDEV_VPORT_PROFILE_OP_MIGRATE_IN_START,
> +                           VIR_QEMU_PROCESS_START_AUTODESTROY);
> +    if (rv < 0) {
> +        if (rv == -2)
> +            relabel = true;
>          goto stopjob;
>      }
> +    relabel = true;
>  
>      if (tunnel) {
>          if (virFDStreamOpen(st, dataFD[1]) < 0) {

[...]

Otherwise seems ok,

Pavel