[libvirt] [RFC PATCH] libvirt support to force convergence of live guest migration
Jim Fehlig
jfehlig at suse.com
Wed Jan 29 16:27:00 UTC 2014
Chegu Vinod wrote:
> 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)
>
Vinod,
What is the status of this patch? I see there were a few comments, but
don't see (or perhaps missed) a V2.
> Signed-off-by: Chegu Vinod <chegu_vinod at hp.com>
> ---
> 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;
> }
>
virsh.pod needs updated too.
Do you have time to continue working on this patch? If not, I could
find some cycles to help out. Thanks!
Regards,
Jim
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