[libvirt] [PATCH 4/5] Set qemu migration speed unlimited when migrating to file
From: Jim Fehlig <jfehlig(a)novell.com>
The qemu migration speed default is 32MiB/s as defined in migration.c
/* Migration speed throttling */
static int64_t max_throttle = (32 << 20);
There's no need to throttle migration when targeting a file, so set migration
speed to unlimited prior to migration, and restore to libvirt default value
after migration.
Default units is MB for migrate_set_speed monitor command, so
(INT64_MAX / (1024 * 1024)) is used for unlimited migration speed.
Tested with both json and text monitors.
---
src/qemu/qemu_migration.c | 17 +++++++++++++++++
1 files changed, 17 insertions(+), 0 deletions(-)
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index 7fd4192..b882d06 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -2718,6 +2718,16 @@ qemuMigrationToFile(struct qemud_driver *driver, virDomainObjPtr
vm,
bool restoreLabel = false;
virCommandPtr cmd = NULL;
int pipeFD[2] = { -1, -1 };
+ unsigned long saveMigBandwidth = priv->migMaxBandwidth;
+
+ /* Increase migration bandwidth to unlimited since target is a file.
+ * Failure to change migration speed is not fatal. */
+ if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) == 0) {
+ qemuMonitorSetMigrationSpeed(priv->mon,
+ QEMU_DOMAIN_FILE_MIG_BANDWIDTH_MAX);
+ priv->migMaxBandwidth = QEMU_DOMAIN_FILE_MIG_BANDWIDTH_MAX;
+ qemuDomainObjExitMonitorWithDriver(driver, vm);
+ }
if (qemuCapsGet(priv->qemuCaps, QEMU_CAPS_MIGRATE_QEMU_FD) &&
(!compressor || pipe(pipeFD) == 0)) {
@@ -2829,6 +2839,13 @@ qemuMigrationToFile(struct qemud_driver *driver, virDomainObjPtr
vm,
ret = 0;
cleanup:
+ /* Restore max migration bandwidth */
+ if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) == 0) {
+ qemuMonitorSetMigrationSpeed(priv->mon, saveMigBandwidth);
+ priv->migMaxBandwidth = saveMigBandwidth;
+ qemuDomainObjExitMonitorWithDriver(driver, vm);
+ }
+
VIR_FORCE_CLOSE(pipeFD[0]);
VIR_FORCE_CLOSE(pipeFD[1]);
virCommandFree(cmd);
--
1.7.5.4