Re: [libvirt] [PATCH 2/6] Added public API to enable post-copy migration

Added a new `libvirt` migration flag `VIR_MIGRATE_POSTCOPY` and the necessary code to pass this flag to qemu as migration capability. Signed-off-by: Cristian Klein <cristian.klein(a)cs.umu.se&gt; --- include/libvirt/libvirt.h.in | 1 + src/libvirt.c | 7 +++++++ src/qemu/qemu_migration.c | 43 +++++++++++++++++++++++++++++++++++++++++++ src/qemu/qemu_migration.h | 3 ++- 4 files changed, 53 insertions(+), 1 deletion(-) diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in index 6371b7b..bdc33c6 100644 --- a/include/libvirt/libvirt.h.in +++ b/include/libvirt/libvirt.h.in @@ -1225,6 +1225,7 @@ typedef enum { VIR_MIGRATE_ABORT_ON_ERROR = (1 << 12), /* abort migration on I/O errors happened during migration */ VIR_MIGRATE_AUTO_CONVERGE = (1 << 13), /* force convergence */ VIR_MIGRATE_RDMA_PIN_ALL = (1 << 14), /* RDMA memory pinning */ + VIR_MIGRATE_POSTCOPY = (1 << 15), /* enable (but don't start) post-copy */ } virDomainMigrateFlags; diff --git a/src/libvirt.c b/src/libvirt.c index 1a285ca..33aeafa 100644 --- a/src/libvirt.c +++ b/src/libvirt.c @@ -5265,6 +5265,7 @@ virDomainMigrateDirect(virDomainPtr domain, * automatically when supported). * VIR_MIGRATE_UNSAFE Force migration even if it is considered unsafe. * VIR_MIGRATE_OFFLINE Migrate offline + * VIR_MIGRATE_POSTCOPY Enable (but don't start) post-copy * * VIR_MIGRATE_TUNNELLED requires that VIR_MIGRATE_PEER2PEER be set. * Applications using the VIR_MIGRATE_PEER2PEER flag will probably @@ -5291,6 +5292,12 @@ virDomainMigrateDirect(virDomainPtr domain, * can use either VIR_MIGRATE_NON_SHARED_DISK or * VIR_MIGRATE_NON_SHARED_INC as they are mutually exclusive. * + * If you want to enable post-copy migration you must set the + * VIR_MIGRATE_POSTCOPY flag. Once migration is active, you may + * start post-copy by calling virDomainMigrateStartPostCopy. + * When to start post-copy is entirely left to the user, libvirt + * only implements the necessary mechanism. + * * In either case it is typically only necessary to specify a * URI if the destination host has multiple interfaces and a * specific interface is required to transmit migration data. diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index a5bd825..bd1f2d6 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -1799,6 +1799,45 @@ qemuMigrationSetOffline(virQEMUDriverPtr driver, static int +qemuMigrationSetPostCopy(virQEMUDriverPtr driver, + virDomainObjPtr vm, + qemuDomainAsyncJob job)

+{ + qemuDomainObjPrivatePtr priv = vm->privateData; + int ret; + + if (qemuDomainObjEnterMonitorAsync(driver, vm, job) < 0) + return -1; + + ret = qemuMonitorGetMigrationCapability( + priv->mon, + QEMU_MONITOR_MIGRATION_CAPS_POSTCOPY);

+ + if (ret < 0) { + goto cleanup; + } else if (ret == 0) { + if (job == QEMU_ASYNC_JOB_MIGRATION_IN) { + virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s", + _("Post-copy migration is not supported by " + "target QEMU binary")); + } else { + virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s", + _("Post-copy migration is not supported by " + "source QEMU binary")); + } + ret = -1; + goto cleanup; + } + + ret = qemuMonitorSetMigrationCapability( + priv->mon, + QEMU_MONITOR_MIGRATION_CAPS_POSTCOPY); + + cleanup: + qemuDomainObjExitMonitor(driver, vm); + return ret; +} +static int qemuMigrationSetCompression(virQEMUDriverPtr driver, virDomainObjPtr vm, qemuDomainAsyncJob job) @@ -3580,6 +3619,10 @@ qemuMigrationRun(virQEMUDriverPtr driver, if (flags & VIR_MIGRATE_RDMA_PIN_ALL && qemuMigrationSetPinAll(driver, vm, QEMU_ASYNC_JOB_MIGRATION_OUT) < 0) + + if (flags & VIR_MIGRATE_POSTCOPY && + qemuMigrationSetPostCopy(driver, vm, + QEMU_ASYNC_JOB_MIGRATION_OUT) < 0) goto cleanup; if (qemuDomainObjEnterMonitorAsync(driver, vm,

diff --git a/src/qemu/qemu_migration.h b/src/qemu/qemu_migration.h index e7a90c3..349c9c4 100644 --- a/src/qemu/qemu_migration.h +++ b/src/qemu/qemu_migration.h @@ -41,7 +41,8 @@ VIR_MIGRATE_COMPRESSED | \ VIR_MIGRATE_ABORT_ON_ERROR | \ VIR_MIGRATE_AUTO_CONVERGE | \ - VIR_MIGRATE_RDMA_PIN_ALL) + VIR_MIGRATE_RDMA_PIN_ALL | \ + VIR_MIGRATE_POSTCOPY) /* All supported migration parameters and their types. */ # define QEMU_MIGRATION_PARAMETERS \