libvirt support to force convergence of live guest migration

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 patch includes the libvirt support needed to trigger this
feature. (Testing is in progress)

Signed-off-by:  Chegu Vinod <chegu_vinod@hp.com>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
index 295d5511b9baee7c1288d8e5ecd229081eb332a3..82c602b6d189d4219d1cdabc7801bd4f99e66489 100644 (file)
--- a/include/libvirt/libvirt.h.in
+++ b/include/libvirt/libvirt.h.in
@@ -1200,6 +1200,7 @@ 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 convergence */
 } virDomainMigrateFlags;
 
 

diff --git a/src/libvirt.c b/src/libvirt.c
index 2201b0733639f350d45e7c85b707235af6b283c0..c5c3136d0ba2e716394a8cfe2c80ecaae77ad53c 100644 (file)
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -4408,7 +4408,8 @@ virDomainMigrateVersion1(virDomainPtr domain,
     if (ret == 0 && info.state == VIR_DOMAIN_PAUSED)
         flags |= VIR_MIGRATE_PAUSED;
 
-    destflags = flags & ~VIR_MIGRATE_ABORT_ON_ERROR;
+    destflags = flags & ~(VIR_MIGRATE_ABORT_ON_ERROR |
+                          VIR_MIGRATE_AUTO_CONVERGE);
 
     /* Prepare the migration.
      *
@@ -4538,7 +4539,8 @@ virDomainMigrateVersion2(virDomainPtr domain,
     if (ret == 0 && info.state == VIR_DOMAIN_PAUSED)
         flags |= VIR_MIGRATE_PAUSED;
 
-    destflags = flags & ~VIR_MIGRATE_ABORT_ON_ERROR;
+    destflags = flags & ~(VIR_MIGRATE_ABORT_ON_ERROR |
+                          VIR_MIGRATE_AUTO_CONVERGE);
 
     VIR_DEBUG("Prepare2 %p flags=%lx", dconn, destflags);
     ret = dconn->driver->domainMigratePrepare2
@@ -4710,7 +4712,8 @@ virDomainMigrateVersion3Full(virDomainPtr domain,
     if (ret == 0 && state == VIR_DOMAIN_PAUSED)
         flags |= VIR_MIGRATE_PAUSED;
 
-    destflags = flags & ~VIR_MIGRATE_ABORT_ON_ERROR;
+    destflags = flags & ~(VIR_MIGRATE_ABORT_ON_ERROR |
+                          VIR_MIGRATE_AUTO_CONVERGE);
 
     VIR_DEBUG("Prepare3 %p flags=%x", dconn, destflags);
     cookiein = cookieout;

diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index ab6f2878adac5f15c84aa93057b0eba3de050471..57e2436949aed983de45d8cd0fbdccb7f948cff9 100644 (file)
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -1621,6 +1621,41 @@ cleanup:
     return ret;
 }
 
+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 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)
@@ -3234,6 +3269,11 @@ 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;
@@ -3587,7 +3627,8 @@ static int doPeer2PeerMigrate2(virQEMUDriverPtr driver,
     if (virDomainObjGetState(vm, NULL) == VIR_DOMAIN_PAUSED)
         flags |= VIR_MIGRATE_PAUSED;
 
-    destflags = flags & ~VIR_MIGRATE_ABORT_ON_ERROR;
+    destflags = flags & ~(VIR_MIGRATE_ABORT_ON_ERROR |
+                          VIR_MIGRATE_AUTO_CONVERGE);
 
     VIR_DEBUG("Prepare2 %p", dconn);
     if (flags & VIR_MIGRATE_TUNNELLED) {
@@ -3780,7 +3821,8 @@ doPeer2PeerMigrate3(virQEMUDriverPtr driver,
     if (virDomainObjGetState(vm, NULL) == VIR_DOMAIN_PAUSED)
         flags |= VIR_MIGRATE_PAUSED;
 
-    destflags = flags & ~VIR_MIGRATE_ABORT_ON_ERROR;
+    destflags = flags & ~(VIR_MIGRATE_ABORT_ON_ERROR |
+                          VIR_MIGRATE_AUTO_CONVERGE);
 
     VIR_DEBUG("Prepare3 %p", dconn);
     cookiein = cookieout;

diff --git a/src/qemu/qemu_migration.h b/src/qemu/qemu_migration.h
index cafa2a299811194ad6a7765c01be9d2c35a26c2d..a802fb7ee677b41bce27c31009efb5bb11d46120 100644 (file)
--- a/src/qemu/qemu_migration.h
+++ b/src/qemu/qemu_migration.h
@@ -39,7 +39,8 @@
      VIR_MIGRATE_UNSAFE |                       \
      VIR_MIGRATE_OFFLINE |                      \
      VIR_MIGRATE_COMPRESSED |                   \
-     VIR_MIGRATE_ABORT_ON_ERROR)
+     VIR_MIGRATE_ABORT_ON_ERROR |               \
+     VIR_MIGRATE_AUTO_CONVERGE)
 
 /* All supported migration parameters and their types. */
 # define QEMU_MIGRATION_PARAMETERS                              \

diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index 48fc51cf87e722694ffb6ce9e0ef7122da1eb1d5..357c9709fc9210e93378afb744e23966d81cbceb 100644 (file)
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -121,7 +121,7 @@ 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 f626cc1223a2a31148295f2138f7fdf5d78abf8c..d8f1d10c32586cfbf39b1579fedc0635d3201cde 100644 (file)
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -451,6 +451,7 @@ 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 eb3397df565ed575479b2d06f5b9cf9233ce742e..06647743415fd840b8138c922ab5003169d1f4da 100644 (file)
--- a/tools/virsh-domain.c
+++ b/tools/virsh-domain.c
@@ -8757,6 +8757,10 @@ 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 convergence during live migration")
+    },
     {.name = "abort-on-error",
      .type = VSH_OT_BOOL,
      .help = N_("abort on soft errors during migration")
@@ -8901,6 +8905,9 @@ 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;
     }