Re: [libvirt] [PATCH v13] support offline migration

> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c > index 978af57..6c2bf98 100644 > --- a/src/qemu/qemu_driver.c > +++ b/src/qemu/qemu_driver.c > @@ -9796,7 +9796,7 @@ qemuDomainMigrateBegin3(virDomainPtr domain, > asyncJob = QEMU_ASYNC_JOB_NONE; > } > > - if (!virDomainObjIsActive(vm)) { > + if (!virDomainObjIsActive(vm) && !(flags & VIR_MIGRATE_OFFLINE)) { > virReportError(VIR_ERR_OPERATION_INVALID, > "%s", _("domain is not running")); > goto endjob; > @@ -9805,9 +9805,9 @@ qemuDomainMigrateBegin3(virDomainPtr domain, > /* Check if there is any ejected media. > * We don't want to require them on the destination. > */ > - > - if (qemuDomainCheckEjectableMedia(driver, vm, asyncJob) < 0) > - goto endjob; > + if (virDomainObjIsActive(vm)) > + if (qemuDomainCheckEjectableMedia(driver, vm, asyncJob) < 0) > + goto endjob; > > if (!(xml = qemuMigrationBegin(driver, vm, xmlin, dname, > cookieout, cookieoutlen, What if you want to offline migrate a domain that is currently running? I think it's better to first move qemuDomainCheckEjectableMedia down to qemuMigrationBegin in a separate patch and then just use the code from v12 (without using the offline label).

> diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c > index 5f8a9c5..66fbc02 100644 > --- a/src/qemu/qemu_migration.c > +++ b/src/qemu/qemu_migration.c > @@ -72,6 +72,7 @@ enum qemuMigrationCookieFlags { > QEMU_MIGRATION_COOKIE_FLAG_LOCKSTATE, > QEMU_MIGRATION_COOKIE_FLAG_PERSISTENT, > QEMU_MIGRATION_COOKIE_FLAG_NETWORK, > + QEMU_MIGRATION_COOKIE_FLAG_OFFLINE, > > QEMU_MIGRATION_COOKIE_FLAG_LAST > }; > @@ -79,13 +80,14 @@ enum qemuMigrationCookieFlags { > VIR_ENUM_DECL(qemuMigrationCookieFlag); > VIR_ENUM_IMPL(qemuMigrationCookieFlag, > QEMU_MIGRATION_COOKIE_FLAG_LAST, > - "graphics", "lockstate", "persistent", "network"); > + "graphics", "lockstate", "persistent", "network", "offline"); > > enum qemuMigrationCookieFeatures { > QEMU_MIGRATION_COOKIE_GRAPHICS = (1 << QEMU_MIGRATION_COOKIE_FLAG_GRAPHICS), > QEMU_MIGRATION_COOKIE_LOCKSTATE = (1 << QEMU_MIGRATION_COOKIE_FLAG_LOCKSTATE), > QEMU_MIGRATION_COOKIE_PERSISTENT = (1 << QEMU_MIGRATION_COOKIE_FLAG_PERSISTENT), > QEMU_MIGRATION_COOKIE_NETWORK = (1 << QEMU_MIGRATION_COOKIE_FLAG_NETWORK), > + QEMU_MIGRATION_COOKIE_OFFLINE = (1 << QEMU_MIGRATION_COOKIE_FLAG_OFFLINE), > }; > > typedef struct _qemuMigrationCookieGraphics qemuMigrationCookieGraphics; > @@ -594,6 +596,9 @@ qemuMigrationCookieXMLFormat(struct qemud_driver *driver, > if ((mig->flags & QEMU_MIGRATION_COOKIE_NETWORK) && mig->network) > qemuMigrationCookieNetworkXMLFormat(buf, mig->network); > > + if (mig->flags & QEMU_MIGRATION_COOKIE_OFFLINE) > + virBufferAsprintf(buf, " <offline/>\n"); > + > virBufferAddLit(buf, "</qemu-migration>\n"); > return 0; > } > @@ -874,6 +879,11 @@ qemuMigrationCookieXMLParse(qemuMigrationCookiePtr mig, > (!(mig->network = qemuMigrationCookieNetworkXMLParse(ctxt)))) > goto error; > > + if ((flags & QEMU_MIGRATION_COOKIE_OFFLINE)) { > + if (virXPathBoolean("count(./offline) > 0", ctxt)) > + mig->flags |= QEMU_MIGRATION_COOKIE_OFFLINE; > + } > + > return 0; > > error: > @@ -938,6 +948,10 @@ qemuMigrationBakeCookie(qemuMigrationCookiePtr mig, > return -1; > } > > + if (flags & QEMU_MIGRATION_COOKIE_OFFLINE) { > + mig->flags |= QEMU_MIGRATION_COOKIE_OFFLINE; > + } > + > if (!(*cookieout = qemuMigrationCookieXMLFormatStr(driver, mig))) > return -1; > Oh, I'm sorry for not noticing this earlier, but why exactly do we need this <offline/> element in migration cookie? It doesn't look like we need to store some additional data required for offline migration. I think just passing the VIR_MIGRATE_OFFLINE flag will be better. Not to mention that if an older libvirt gets a cookie with <offline/> element, it will just ignore it while passing a flag (which the code should already been doing anyway) should make it fail for unsupported flag.

> @@ -1443,6 +1457,24 @@ char *qemuMigrationBegin(struct qemud_driver *driver, > QEMU_MIGRATION_COOKIE_LOCKSTATE) < 0) > goto cleanup; > > + if (flags & VIR_MIGRATE_OFFLINE) { > + if (flags & (VIR_MIGRATE_NON_SHARED_DISK| > + VIR_MIGRATE_NON_SHARED_INC)) { > + virReportError(VIR_ERR_OPERATION_INVALID, > + "%s", _("offline migration cannot handle non-shared storage")); > + goto cleanup; > + } > + if (!(flags & VIR_MIGRATE_PERSIST_DEST)) { > + virReportError(VIR_ERR_OPERATION_INVALID, > + "%s", _("offline migration must be specified with the persistent flag set")); > + goto cleanup; > + } > + if (qemuMigrationBakeCookie(mig, driver, vm, > + cookieout, cookieoutlen, > + QEMU_MIGRATION_COOKIE_OFFLINE) < 0) > + goto cleanup; > + } > + > if (xmlin) { > if (!(def = virDomainDefParseString(driver->caps, xmlin, > QEMU_EXPECTED_VIRT_TYPES, Good, just wrap the two long lines and create a separate patch (which this one will depend on) to move qemuDomainCheckEjectableMedia here as well. > @@ -1607,6 +1639,15 @@ qemuMigrationPrepareAny(struct qemud_driver *driver, > goto endjob; > } > > + if (!(mig = qemuMigrationEatCookie(driver, vm, cookiein, cookieinlen, > + QEMU_MIGRATION_COOKIE_OFFLINE))) > + return ret; AS I wrote in my last review, this needs to call goto endjob rather than returning directly.

> + > + if (mig->flags & QEMU_MIGRATION_COOKIE_OFFLINE) { > + ret = 0; > + goto done; > + } > + > /* Start the QEMU daemon, with the same command-line arguments plus > * -incoming $migrateFrom > */ ... > @@ -2150,6 +2192,9 @@ qemuMigrationRun(struct qemud_driver *driver, > return -1; > } > > + if (flags & VIR_MIGRATE_OFFLINE) > + return 0; > + > if (!(mig = qemuMigrationEatCookie(driver, vm, cookiein, cookieinlen, > QEMU_MIGRATION_COOKIE_GRAPHICS))) > goto cleanup; I still think we should not even get into qemuMigrationRun when doing offline migration.

> @@ -2665,7 +2710,12 @@ static int doPeer2PeerMigrate3(struct qemud_driver *driver, > uri, &uri_out, flags, dname, resource, dom_xml); > qemuDomainObjExitRemoteWithDriver(driver, vm); > } > + > VIR_FREE(dom_xml); > + > + if (flags & VIR_MIGRATE_OFFLINE) > + goto cleanup; > + > if (ret == -1) > goto cleanup; > Quoting from my previous review: This will skip not only Perform but also Finish phase in peer-to-peer migration. You want to jump to finish label and do that *after* the check for ret == 1.

> @@ -2771,7 +2821,7 @@ finish: > vm->def->name); > > cleanup: > - if (ddomain) { > + if (ddomain || (flags & VIR_MIGRATE_OFFLINE)) { > virObjectUnref(ddomain); > ret = 0; > } else { I think this should not be changed at all.

... > diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c > index 393b67b..54ba63a 100644 > --- a/tools/virsh-domain.c > +++ b/tools/virsh-domain.c > @@ -6644,6 +6644,7 @@ static const vshCmdInfo info_migrate[] = { > > static const vshCmdOptDef opts_migrate[] = { > {"live", VSH_OT_BOOL, 0, N_("live migration")}, > + {"offline", VSH_OT_BOOL, 0, N_("offline (domain's inactive) migration")}, > {"p2p", VSH_OT_BOOL, 0, N_("peer-2-peer migration")}, > {"direct", VSH_OT_BOOL, 0, N_("direct migration")}, > {"tunneled", VSH_OT_ALIAS, 0, "tunnelled"}, > @@ -6729,6 +6730,15 @@ doMigrate(void *opaque) > if (vshCommandOptBool(cmd, "unsafe")) > flags |= VIR_MIGRATE_UNSAFE; > > + if (vshCommandOptBool(cmd, "offline")) { > + flags |= VIR_MIGRATE_OFFLINE; > + } > + > + if (virDomainIsActive(dom) && (flags & VIR_MIGRATE_OFFLINE)) { > + vshError(ctl, "%s", _("domain is active, offline migration for inactive domain only")); > + goto out; > + } > + Another thing I didn't notice last time :-( Is there any reason why offline migrating a running domain should be forbidden? But even if there was a reason, this check doesn't belong to virsh.

And --ofline flag for virsh migrate should also be documented in virsh man page.

Jirka