[libvirt] [PATCH RFC 26/39] qemu: process: Setup disk io throttling for -blockdev
The proper way to do this would be to use the 'throttle' driver but
unfortunately it can't change the 'throttle_group' so we can't provide
feature parity. This hack uses the block_set_io_throttle command to do
so until we can properly replace it.
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/qemu/qemu_process.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 50 insertions(+)
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 4b681a892e..928036172d 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -6233,6 +6233,53 @@ qemuProcessGenID(virDomainObjPtr vm,
}
+/**
+ * qemuProcessSetupDiskThrottlingBlockdev:
+ *
+ * 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.
+ */
+static int
+qemuProcessSetupDiskThrottlingBlockdev(virQEMUDriverPtr driver,
+ virDomainObjPtr vm,
+ qemuDomainAsyncJob asyncJob)
+{
+ qemuDomainObjPrivatePtr priv = vm->privateData;
+ size_t i;
+ int ret = -1;
+
+ if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKDEV))
+ return 0;
+
+ VIR_DEBUG("Setting up disk throttling for -blockdev via
block_set_io_throttle");
+
+ if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
+ return -1;
+
+ for (i = 0; i < vm->def->ndisks; i++) {
+ virDomainDiskDefPtr disk = vm->def->disks[i];
+ qemuDomainDiskPrivatePtr diskPriv = QEMU_DOMAIN_DISK_PRIVATE(disk);
+
+ if (!qemuDiskConfigBlkdeviotuneEnabled(disk))
+ continue;
+
+ if (qemuMonitorSetBlockIoThrottle(qemuDomainGetMonitor(vm), NULL,
+ diskPriv->backendQomName,
+ &disk->blkdeviotune,
+ true, true, true) < 0)
+ goto cleanup;
+ }
+
+ ret = 0;
+
+ cleanup:
+ if (qemuDomainObjExitMonitor(driver, vm) < 0)
+ ret = -1;
+ return ret;
+}
+
+
/**
* qemuProcessLaunch:
*
@@ -6551,6 +6598,9 @@ qemuProcessLaunch(virConnectPtr conn,
if (qemuProcessSetupBalloon(driver, vm, asyncJob) < 0)
goto cleanup;
+ if (qemuProcessSetupDiskThrottlingBlockdev(driver, vm, asyncJob) < 0)
+ goto cleanup;
+
/* Since CPUs were not started yet, the balloon could not return the memory
* to the host and thus cur_balloon needs to be updated so that GetXMLdesc
* and friends return the correct size in case they can't grab the job */
--
2.16.2