[libvirt] [PATCH 3/3] qemu: hotplug: Setup disk throttling with blockdev
With blockdev we must issue the block_set_io_throttle QMP command to
setup disk throttling as we currently can't do it with the 'throttle'
layer.
Unfortunately there's nothing we can do if it fails.
https://bugzilla.redhat.com/show_bug.cgi?id=1733163
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/qemu/qemu_hotplug.c | 18 +++++++++++++++++-
src/qemu/qemu_process.c | 1 +
2 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index 30aa6d2344..a7034fd298 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -617,6 +617,7 @@ qemuDomainAttachDiskGeneric(virQEMUDriverPtr driver,
VIR_AUTOUNREF(virQEMUDriverConfigPtr) cfg = virQEMUDriverGetConfig(driver);
VIR_AUTOPTR(virJSONValue) corProps = NULL;
VIR_AUTOFREE(char *) corAlias = NULL;
+ bool blockdev = virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKDEV);
if (qemuDomainStorageSourceChainAccessAllow(driver, vm, disk->src) < 0)
goto cleanup;
@@ -627,7 +628,7 @@ qemuDomainAttachDiskGeneric(virQEMUDriverPtr driver,
if (qemuDomainPrepareDiskSource(disk, priv, cfg) < 0)
goto error;
- if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKDEV)) {
+ if (blockdev) {
if (disk->copy_on_read == VIR_TRISTATE_SWITCH_ON &&
!(corProps = qemuBlockStorageGetCopyOnReadProps(disk)))
goto cleanup;
@@ -667,6 +668,21 @@ qemuDomainAttachDiskGeneric(virQEMUDriverPtr driver,
goto exit_monitor;
}
+ /* Setup throttling of disk via block_set_io_throttle QMP command. This
+ * is a hack until the 'throttle' blockdev driver will support modification
+ * of the trhottle group. See also qemuProcessSetupDiskThrottlingBlockdev.
+ * As there isn't anything sane to do if this fails, let's just return
+ * success.
+ */
+ if (blockdev &&
+ qemuDiskConfigBlkdeviotuneEnabled(disk)) {
+ qemuDomainDiskPrivatePtr diskPriv = QEMU_DOMAIN_DISK_PRIVATE(disk);
+ if (qemuMonitorSetBlockIoThrottle(priv->mon, NULL, diskPriv->qomName,
+ &disk->blkdeviotune,
+ true, true, true) < 0)
+ VIR_WARN("failed to set blkdeviotune for '%s' of
'%s'", disk->dst, vm->def->name);
+ }
+
if (qemuDomainObjExitMonitor(driver, vm) < 0) {
ret = -2;
goto error;
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index c9921646e9..61b03c8a2d 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -6671,6 +6671,7 @@ qemuProcessGenID(virDomainObjPtr vm,
* Sets up disk trottling for -blockdev via block_set_io_throttle monitor
* command. This hack should be replaced by proper use of the 'throttle'
* blockdev driver in qemu once it will support changing of the throttle group.
+ * Same hack is done in qemuDomainAttachDiskGeneric.
*/
static int
qemuProcessSetupDiskThrottlingBlockdev(virQEMUDriverPtr driver,
--
2.21.0