Re: [libvirt PATCH 54/80] qemu: Implement VIR_MIGRATE_POSTCOPY_RESUME for Begin phase

On Wed, May 18, 2022 at 15:40:18 +0200, Jiri Denemark wrote: > On Thu, May 12, 2022 at 14:14:15 +0200, Peter Krempa wrote: > > > +static char * > > > +qemuMigrationSrcBeginResume(virQEMUDriver *driver, > > > + virDomainObj *vm, > > > + const char *xmlin, > > > + char **cookieout, > > > + int *cookieoutlen, > > > + unsigned long flags) > > > +{ > > > + virDomainJobStatus status; > > > + > > > + if (qemuMigrationAnyRefreshStatus(driver, vm, VIR_ASYNC_JOB_MIGRATION_OUT, > > > + &status) < 0) > > > + return NULL; > > > + > > > + if (status != VIR_DOMAIN_JOB_STATUS_POSTCOPY_PAUSED) { > > > + virReportError(VIR_ERR_OPERATION_INVALID, "%s", > > > + _("QEMU reports migration is still running")); > > > + return NULL; > > > + } > > > + > > > + return qemuMigrationSrcBeginXML(driver, vm, xmlin, > > > + cookieout, cookieoutlen, 0, NULL, 0, flags); > > > > Certain steps here around the non-shared-storage migration are redundant > > at this point and IMO should be skipped. > > Which is what happens in qemuMigrationSrcBegin: > > if (flags & VIR_MIGRATE_POSTCOPY_RESUME) { > xml = qemuMigrationSrcBeginResumePhase(...); > goto cleanup; > } > > ... > > Or did I miss anything? In 'qemuMigrationSrcBeginXML' qemuMigrationSrcBeginPhaseBlockDirtyBitmaps is called which does a bunch of setup for bitmap migration which is pointless when recovering as storage is copied already if the CPUs are running on the destination.