Migrating domains with disks using cache != none is unsafe unless the disk images are stored on coherent clustered filesystem. Thus we forbid migrating such domains unless VIR_MIGRATE_UNSAFE flags is used. --- src/qemu/qemu_driver.c | 3 ++- src/qemu/qemu_migration.c | 36 ++++++++++++++++++++++++++++++++---- src/qemu/qemu_migration.h | 6 ++++-- 3 files changed, 38 insertions(+), 7 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 717bdf1..63a0703 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -8767,7 +8767,8 @@ qemuDomainMigrateBegin3(virDomainPtr domain, goto endjob; if (!(xml = qemuMigrationBegin(driver, vm, xmlin, dname, - cookieout, cookieoutlen))) + cookieout, cookieoutlen, + flags))) goto endjob; if ((flags & VIR_MIGRATE_CHANGE_PROTECTION)) { diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index f0af494..127b35c 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -817,6 +817,27 @@ qemuMigrationIsAllowed(struct qemud_driver *driver, virDomainObjPtr vm, return true; } +static bool +qemuMigrationIsSafe(virDomainDefPtr def) +{ + int i; + + for (i = 0 ; i < def->ndisks ; i++) { + virDomainDiskDefPtr disk = def->disks[i]; + + /* shared && !readonly implies cache=none */ + if (disk->cachemode != VIR_DOMAIN_DISK_CACHE_DISABLE && + (disk->cachemode || !disk->shared || disk->readonly)) { + qemuReportError(VIR_ERR_MIGRATE_UNSAFE, "%s", + _("Migration may lead to data corruption if disks" + " use cache != none")); + return false; + } + } + + return true; +} + /** qemuMigrationSetOffline * Pause domain for non-live migration. */ @@ -1010,7 +1031,8 @@ char *qemuMigrationBegin(struct qemud_driver *driver, const char *xmlin, const char *dname, char **cookieout, - int *cookieoutlen) + int *cookieoutlen, + unsigned long flags) { char *rv = NULL; qemuMigrationCookiePtr mig = NULL; @@ -1018,9 +1040,9 @@ char *qemuMigrationBegin(struct qemud_driver *driver, qemuDomainObjPrivatePtr priv = vm->privateData; VIR_DEBUG("driver=%p, vm=%p, xmlin=%s, dname=%s," - " cookieout=%p, cookieoutlen=%p", + " cookieout=%p, cookieoutlen=%p, flags=%lx", driver, vm, NULLSTR(xmlin), NULLSTR(dname), - cookieout, cookieoutlen); + cookieout, cookieoutlen, flags); /* Only set the phase if we are inside QEMU_ASYNC_JOB_MIGRATION_OUT. * Otherwise we will start the async job later in the perform phase losing @@ -1032,6 +1054,9 @@ char *qemuMigrationBegin(struct qemud_driver *driver, if (!qemuMigrationIsAllowed(driver, vm, NULL)) goto cleanup; + if (!(flags & VIR_MIGRATE_UNSAFE) && !qemuMigrationIsSafe(vm->def)) + goto cleanup; + if (!(mig = qemuMigrationEatCookie(driver, vm, NULL, 0, 0))) goto cleanup; @@ -2070,7 +2095,7 @@ static int doPeer2PeerMigrate3(struct qemud_driver *driver, * a single job. */ dom_xml = qemuMigrationBegin(driver, vm, xmlin, dname, - &cookieout, &cookieoutlen); + &cookieout, &cookieoutlen, flags); if (!dom_xml) goto cleanup; @@ -2354,6 +2379,9 @@ qemuMigrationPerformJob(struct qemud_driver *driver, if (!qemuMigrationIsAllowed(driver, vm, NULL)) goto cleanup; + if (!(flags & VIR_MIGRATE_UNSAFE) && !qemuMigrationIsSafe(vm->def)) + goto cleanup; + resume = virDomainObjGetState(vm, NULL) == VIR_DOMAIN_RUNNING; if ((flags & (VIR_MIGRATE_TUNNELLED | VIR_MIGRATE_PEER2PEER))) { diff --git a/src/qemu/qemu_migration.h b/src/qemu/qemu_migration.h index f806ca1..41e4eac 100644 --- a/src/qemu/qemu_migration.h +++ b/src/qemu/qemu_migration.h @@ -35,7 +35,8 @@ VIR_MIGRATE_PAUSED | \ VIR_MIGRATE_NON_SHARED_DISK | \ VIR_MIGRATE_NON_SHARED_INC | \ - VIR_MIGRATE_CHANGE_PROTECTION) + VIR_MIGRATE_CHANGE_PROTECTION | \ + VIR_MIGRATE_UNSAFE) enum qemuMigrationJobPhase { QEMU_MIGRATION_PHASE_NONE = 0, @@ -81,7 +82,8 @@ char *qemuMigrationBegin(struct qemud_driver *driver, const char *xmlin, const char *dname, char **cookieout, - int *cookieoutlen); + int *cookieoutlen, + unsigned long flags); int qemuMigrationPrepareTunnel(struct qemud_driver *driver, virConnectPtr dconn, -- 1.7.8.4 -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list