4:04 a.m.
On Thu, Jan 7, 2021 at 5:23 PM Peter Krempa <pkrempa(a)redhat.com> wrote:
Similarly to startup of the VM qemu doesn't like setting
throttling for
an empty drive. Just skip it since we do the correct thing once new
media is inserted.
Resolves: https://gitlab.com/libvirt/libvirt/-/issues/117
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
CC: Han Han <hhan(a)redhat.com>
Please test this commit since you have the environment prepared.
src/qemu/qemu_driver.c | 25 ++++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 1283e61785..027617deef 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -16301,16 +16301,23 @@ qemuDomainSetBlockIoTune(virDomainPtr dom,
#undef CHECK_MAX
- qemuDomainObjEnterMonitor(driver, vm);
- ret = qemuMonitorSetBlockIoThrottle(priv->mon, drivealias, qdevid,
- &info, supportMaxOptions,
- set_fields &
QEMU_BLOCK_IOTUNE_SET_GROUP_NAME,
- supportMaxLengthOptions);
- if (qemuDomainObjExitMonitor(driver, vm) < 0)
+ /* blockdev-based qemu doesn't want to set the throttling when a
cdrom
+ * is empty. Skip the monitor call here since we will set the
throttling
+ * once new media is inserted */
+ if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKDEV) ||
+ !virStorageSourceIsEmpty(disk->src)) {
+
+ qemuDomainObjEnterMonitor(driver, vm);
+ ret = qemuMonitorSetBlockIoThrottle(priv->mon, drivealias,
qdevid,
+ &info, supportMaxOptions,
+ set_fields &
QEMU_BLOCK_IOTUNE_SET_GROUP_NAME,
+ supportMaxLengthOptions);
+ if (qemuDomainObjExitMonitor(driver, vm) < 0)
+ ret = -1;
+ if (ret < 0)
+ goto endjob;
ret = -1;
- if (ret < 0)
- goto endjob;
- ret = -1;
+ }
virDomainDiskSetBlockIOTune(disk, &info);
--
2.29.2
Test on libvirt-v6.10.0-335-gc5904929e8 qemu-5.2.0-4.fc34.x86_64:
Start a VM with
empty cdrom:
<disk type="file" device="cdrom">
<driver name="qemu"/>
<target dev="sda" bus="scsi"/>
<readonly/>
<alias name="scsi0-0-0"/>
<address type="drive" controller="0" bus="0"
target="0" unit="0"/>
</disk>
Set the blkiotune for the cdrom:
➜ ~ virsh blkdeviotune test sda --total-bytes-sec 10000
➜ ~ virsh blkdeviotune test sda --group-name test
Dumpxml:
<disk type="file" device="cdrom">
<driver name="qemu"/>
<target dev="sda" bus="scsi"/>
<iotune>
<total_bytes_sec>10000</total_bytes_sec>
<group_name>test</group_name>
</iotune>
<readonly/>
<alias name="scsi0-0-0"/>
<address type="drive" controller="0" bus="0"
target="0" unit="0"/>
</disk>
Insert the media:
➜ ~ virsh change-media test sda --insert /var/lib/libvirt/images/boot.iso
Successfully inserted media.
QMP log:
56.306 > 0x7f8b04043030
{"execute":"blockdev-open-tray","arguments":{"id":"scsi0-0-0","force":false},"id":"libvirt-379"}
56.310 ! 0x7f8b04043030 {"timestamp": {"seconds": 1610013536,
"microseconds": 856358}, "event": "DEVICE_TRAY_MOVED",
"data": {"device":
"", "tray-open": true, "id": "scsi0-0-0"}}
56.311 < 0x7f8b04043030 {"return": {}, "id":
"libvirt-379"}
56.311 > 0x7f8b04043030
{"execute":"blockdev-remove-medium","arguments":{"id":"scsi0-0-0"},"id":"libvirt-380"}
56.314 < 0x7f8b04043030 {"return": {}, "id":
"libvirt-380"}
56.314 > 0x7f8b04043030
{"execute":"blockdev-add","arguments":{"driver":"file","filename":"/var/lib/libvirt/images/boot.iso","node-name":"libvirt-3-storage","auto-read-only":true,"discard":"unmap"},"id":"libvirt-381"}
56.318 < 0x7f8b04043030 {"return": {}, "id":
"libvirt-381"}
56.319 > 0x7f8b04043030
{"execute":"blockdev-add","arguments":{"node-name":"libvirt-3-format","read-only":true,"driver":"raw","file":"libvirt-3-storage"},"id":"libvirt-382"}
56.322 < 0x7f8b04043030 {"return": {}, "id":
"libvirt-382"}
56.322 > 0x7f8b04043030
{"execute":"blockdev-insert-medium","arguments":{"id":"scsi0-0-0","node-name":"libvirt-3-format"},"id":"libvirt-383"}
56.325 < 0x7f8b04043030 {"return": {}, "id":
"libvirt-383"}
56.325 > 0x7f8b04043030
{"execute":"block_set_io_throttle","arguments":{"id":"scsi0-0-0","bps":10000,"bps_rd":0,"bps_wr":0,"iops":0,"iops_rd":0,"iops_wr":0,"bps_max":0,"bps_rd_max":0,"bps_wr_max":0,"iops_max":0,"iops_rd_max":0,"iops_wr_max":0,"iops_size":0,"group":"test"},"id":"libvirt-384"}
56.331 < 0x7f8b04043030 {"return": {}, "id":
"libvirt-384"}
56.331 > 0x7f8b04043030
{"execute":"blockdev-close-tray","arguments":{"id":"scsi0-0-0"},"id":"libvirt-385"}
56.333 ! 0x7f8b04043030 {"timestamp": {"seconds": 1610013536,
"microseconds": 880060}, "event": "DEVICE_TRAY_MOVED",
"data": {"device":
"", "tray-open": false, "id": "scsi0-0-0"}}
56.333 < 0x7f8b04043030 {"return": {}, "id":
"libvirt-385"}
So the total_bytes_sec and group_name are set after medium inserted.
Eject the media:
➜ ~ virsh change-media test sda --eject
Successfully ejected media.
Dumpxml:
<disk type="file" device="cdrom">
<driver name="qemu" type="raw"/>
<source index="4"/>
<target dev="sda" bus="scsi"/>
<iotune>
<total_bytes_sec>10000</total_bytes_sec>
<group_name>test</group_name>
</iotune>
<readonly/>
<alias name="scsi0-0-0"/>
<address type="drive" controller="0" bus="0"
target="0" unit="0"/>
</disk>
Work as expected.
--
Tested-by: Han Han <hhan(a)redhat.com>