On Mon, Nov 05, 2012 at 12:17:50 +0800, liguang wrote:
> original migration did not aware of offline case,
> so, try to support offline migration quietly
> (did not disturb original migration) by pass
> VIR_MIGRATE_OFFLINE flag to migration APIs if only
> the domain is really inactive, and
> migration process will not puzzled by domain
> offline and exit unexpectedly.
> these changes did not take care of disk images the
> domain required, for them could be transferred by
> other APIs as suggested, then VIR_MIGRATE_OFFLINE
> must not combined with VIR_MIGRATE_NON_SHARED_*.
> if you want a persistent migration,
> you should do "virsh migrate --persistent" youself.
...
> 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
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