Re: [libvirt] [PATCH v3] qemu: wait for SPICE to migrate

On Thu, Sep 20, 2012 at 01:29:21PM +0200, Michal Privoznik wrote: > Recently, there have been some improvements made to qemu so it > supports seamless migration or something very close to it. > However, it requires libvirt interaction. Once qemu is migrated, > the SPICE server needs to send its internal state to the destination. > Once it's done, it fires SPICE_MIGRATE_COMPLETED event and this > fact is advertised in 'query-spice' output as well. > We must not kill qemu until SPICE server finishes the transfer. > --- > src/qemu/qemu_capabilities.c | 4 +++ > src/qemu/qemu_capabilities.h | 1 + > src/qemu/qemu_command.c | 8 ++++++ > src/qemu/qemu_migration.c | 33 ++++++++++++++++++++++++-- > src/qemu/qemu_monitor.c | 24 +++++++++++++++++++ > src/qemu/qemu_monitor.h | 2 + > src/qemu/qemu_monitor_json.c | 52 ++++++++++++++++++++++++++++++++++++++++++ > src/qemu/qemu_monitor_json.h | 3 ++ > 8 files changed, 124 insertions(+), 3 deletions(-) >

> @@ -940,6 +949,8 @@ qemuMigrationUpdateJobStatus(struct qemud_driver *driver, > > case QEMU_MONITOR_MIGRATION_STATUS_COMPLETED: > priv->job.info.type = VIR_DOMAIN_JOB_COMPLETED; > + if (spice_migrated) > + priv->job.info.type = VIR_DOMAIN_JOB_COMPLETED; This addition doesn't do anything, since the previous line has already set the same value.

I don't find this very readable - it is better to do it as a regular if() IMHO. eg bool wait_for_spice = false; if (...) wait_for_spice = true; > > switch (priv->job.asyncJob) { > case QEMU_ASYNC_JOB_MIGRATION_OUT: > @@ -988,7 +1006,8 @@ qemuMigrationWaitForCompletion(struct qemud_driver *driver, virDomainObjPtr vm, > /* Poll every 50ms for progress & to allow cancellation */ > struct timespec ts = { .tv_sec = 0, .tv_nsec = 50 * 1000 * 1000ull }; > > - if (qemuMigrationUpdateJobStatus(driver, vm, job, asyncJob) < 0) > + if (qemuMigrationUpdateJobStatus(driver, vm, job, > + asyncJob, wait_for_spice) < 0) > goto cleanup; > > if (dconn && virConnectIsAlive(dconn) <= 0) { > @@ -1840,6 +1859,7 @@ qemuMigrationRun(struct qemud_driver *driver, > int fd = -1; > unsigned long migrate_speed = resource ? resource : priv->migMaxBandwidth; > virErrorPtr orig_err = NULL; > + bool wait_for_spice; > > VIR_DEBUG("driver=%p, vm=%p, cookiein=%s, cookieinlen=%d, " > "cookieout=%p, cookieoutlen=%p, flags=%lx, resource=%lu, " > @@ -1848,6 +1868,12 @@ qemuMigrationRun(struct qemud_driver *driver, > cookieout, cookieoutlen, flags, resource, > spec, spec->destType, spec->fwdType); > > + /* If guest uses SPICE and supports seamless migration we have to hold up > + * migration finish until SPICE server transfers its data */ > + wait_for_spice = (vm->def->ngraphics == 1) && > + (vm->def->graphics[0]->type == VIR_DOMAIN_GRAPHICS_TYPE_SPICE) && > + qemuCapsGet(priv->caps, QEMU_CAPS_SEAMLESS_MIGRATION); Same comment as before. Since both callers of qemuMigrateUpdateJobStatus() have to repeat this logic, why not push this down into that method itself and make 'wait_for_spice' be a local variable there instead of a param.