Busy enterprise workloads hosted on large sized VM's tend to dirty memory faster than the transfer rate achieved via live guest migration. Despite some good recent improvements (& using dedicated 10Gig NICs between hosts) the live migration may NOT converge. Recently support was added in qemu (version 1.6) to allow a user to choose if they wish to force convergence of their migration via a new migration capability : "auto-converge". This feature allows for qemu to auto-detect lack of convergence and trigger a throttle-down of the VCPUs. This RFC patch includes the libvirt support needed to trigger this feature. (Testing is still in progress) Signed-off-by: Chegu Vinod <chegu_vinod(a)hp.com&gt; --- include/libvirt/libvirt.h.in | 1 + src/qemu/qemu_migration.c | 44 ++++++++++++++++++++++++++++++++++++++++++ src/qemu/qemu_migration.h | 1 + src/qemu/qemu_monitor.c | 2 +- src/qemu/qemu_monitor.h | 1 + tools/virsh-domain.c | 7 ++++++ 6 files changed, 55 insertions(+), 1 deletions(-) diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in index 146a59b..13b0bfc 100644 --- a/include/libvirt/libvirt.h.in +++ b/include/libvirt/libvirt.h.in @@ -1192,6 +1192,7 @@ typedef enum { VIR_MIGRATE_OFFLINE = (1 << 10), /* offline migrate */ VIR_MIGRATE_COMPRESSED = (1 << 11), /* compress data during migration */ VIR_MIGRATE_ABORT_ON_ERROR = (1 << 12), /* abort migration on I/O errors happened during migration */ + VIR_MIGRATE_AUTO_CONVERGE = (1 << 13), /* force auto-convergence during during migration */ } virDomainMigrateFlags; diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index e87ea85..8cc0c56 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -1565,6 +1565,40 @@ cleanup: } static int +qemuMigrationSetAutoConverge(virQEMUDriverPtr driver, + virDomainObjPtr vm, + enum qemuDomainAsyncJob job) +{ + qemuDomainObjPrivatePtr priv = vm->privateData; + int ret; + + if (qemuDomainObjEnterMonitorAsync(driver, vm, job) < 0) + return -1; + + ret = qemuMonitorGetMigrationCapability( + priv->mon, + QEMU_MONITOR_MIGRATION_CAPS_AUTO_CONVERGE); + + if (ret < 0) { + goto cleanup; + } else if (ret == 0) { + virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s", + _("Auto-Converge migration is not supported by " + "QEMU binary")); + ret = -1; + goto cleanup; + } + + ret = qemuMonitorSetMigrationCapability( + priv->mon, + QEMU_MONITOR_MIGRATION_CAPS_AUTO_CONVERGE); + +cleanup: + qemuDomainObjExitMonitor(driver, vm); + return ret; +} + +static int qemuMigrationWaitForSpice(virQEMUDriverPtr driver, virDomainObjPtr vm) { @@ -2389,6 +2423,11 @@ qemuMigrationPrepareAny(virQEMUDriverPtr driver, QEMU_ASYNC_JOB_MIGRATION_IN) < 0) goto stop; + if (flags & VIR_MIGRATE_AUTO_CONVERGE && + qemuMigrationSetAutoConverge(driver, vm, + QEMU_ASYNC_JOB_MIGRATION_IN) < 0) + goto stop; + if (mig->lockState) { VIR_DEBUG("Received lockstate %s", mig->lockState); VIR_FREE(priv->lockState); @@ -3181,6 +3220,11 @@ qemuMigrationRun(virQEMUDriverPtr driver, QEMU_ASYNC_JOB_MIGRATION_OUT) < 0) goto cleanup; + if (flags & VIR_MIGRATE_AUTO_CONVERGE && + qemuMigrationSetAutoConverge(driver, vm, + QEMU_ASYNC_JOB_MIGRATION_OUT) < 0) + goto cleanup; + if (qemuDomainObjEnterMonitorAsync(driver, vm, QEMU_ASYNC_JOB_MIGRATION_OUT) < 0) goto cleanup; diff --git a/src/qemu/qemu_migration.h b/src/qemu/qemu_migration.h index cafa2a2..c4258a1 100644 --- a/src/qemu/qemu_migration.h +++ b/src/qemu/qemu_migration.h @@ -39,6 +39,7 @@ VIR_MIGRATE_UNSAFE | \ VIR_MIGRATE_OFFLINE | \ VIR_MIGRATE_COMPRESSED | \ + VIR_MIGRATE_AUTO_CONVERGE | \ VIR_MIGRATE_ABORT_ON_ERROR) /* All supported migration parameters and their types. */ diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index 1514715..780a29a 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -118,7 +118,7 @@ VIR_ENUM_IMPL(qemuMonitorMigrationStatus, VIR_ENUM_IMPL(qemuMonitorMigrationCaps, QEMU_MONITOR_MIGRATION_CAPS_LAST, - "xbzrle") + "xbzrle", "auto-converge") VIR_ENUM_IMPL(qemuMonitorVMStatus, QEMU_MONITOR_VM_STATUS_LAST, diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h index eabf000..95e70ab 100644 --- a/src/qemu/qemu_monitor.h +++ b/src/qemu/qemu_monitor.h @@ -440,6 +440,7 @@ int qemuMonitorGetSpiceMigrationStatus(qemuMonitorPtr mon, typedef enum { QEMU_MONITOR_MIGRATION_CAPS_XBZRLE, + QEMU_MONITOR_MIGRATION_CAPS_AUTO_CONVERGE, QEMU_MONITOR_MIGRATION_CAPS_LAST } qemuMonitorMigrationCaps; diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c index 1fe138c..d94a81b 100644 --- a/tools/virsh-domain.c +++ b/tools/virsh-domain.c @@ -8532,6 +8532,10 @@ static const vshCmdOptDef opts_migrate[] = { .type = VSH_OT_BOOL, .help = N_("compress repeated pages during live migration") }, + {.name = "auto-converge", + .type = VSH_OT_BOOL, + .help = N_("force auto convergence during live migration") + }, {.name = "abort-on-error", .type = VSH_OT_BOOL, .help = N_("abort on soft errors during migration") @@ -8676,6 +8680,9 @@ doMigrate(void *opaque) if (vshCommandOptBool(cmd, "compressed")) flags |= VIR_MIGRATE_COMPRESSED; + if (vshCommandOptBool(cmd, "auto-converge")) + flags |= VIR_MIGRATE_AUTO_CONVERGE; + if (vshCommandOptBool(cmd, "offline")) { flags |= VIR_MIGRATE_OFFLINE; } -- 1.7.1