Bug 1541921
| Summary: | cachetune cannot work with TCG guest | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Luyao Huang <lhuang> |
| Component: | libvirt | Assignee: | Michal Privoznik <mprivozn> |
| Status: | CLOSED ERRATA | QA Contact: | jiyan <jiyan> |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | 7.5 | CC: | dyuan, xuzhang, yalzhang |
| Target Milestone: | rc | Keywords: | Upstream |
| Target Release: | --- | ||
| Hardware: | x86_64 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | libvirt-4.5.0-1.el7 | Doc Type: | If docs needed, set a value |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2018-10-30 09:52:39 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
Patch proposed upstream: https://www.redhat.com/archives/libvir-list/2018-June/msg01800.html I've just pushed the patch upstream:
commit cb7a4ac4fb9e32f620d800036b1abdd4bed09ce6
Author: Michal Privoznik <mprivozn>
AuthorDate: Thu Jun 28 11:37:09 2018 +0200
Commit: Michal Privoznik <mprivozn>
CommitDate: Thu Jun 28 17:06:52 2018 +0200
qemu: Allow cachetune only for KVM domains
https://bugzilla.redhat.com/show_bug.cgi?id=1541921
In TCG mode, there are no vCPU threads and thus there's nothing
to be placed into resctrl group. Forbid such configuration.
Signed-off-by: Michal Privoznik <mprivozn>
Reviewed-by: Daniel P. Berrangé <berrange>
v4.5.0-rc1-7-gcb7a4ac4fb
Verified this bug on the following components:
qemu-kvm-rhev-2.12.0-7.el7.x86_64
libvirt-4.5.0-1.el7.x86_64
kernel-3.10.0-919.el7.x86_64
Steps:
1. Edit VM with the following configuration and try to save it
# virsh edit b1
<domain type='qemu'>
...
<cputune>
<cachetune vcpus='0'>
<cache id='0' level='3' type='both' size='1' unit='MiB'/>
<cache id='1' level='3' type='both' size='2' unit='MiB'/>
</cachetune>
<cachetune vcpus='1'>
<cache id='0' level='3' type='both' size='2' unit='MiB'/>
<cache id='1' level='3' type='both' size='1' unit='MiB'/>
</cachetune>
<cachetune vcpus='3'>
<cache id='0' level='3' type='both' size='1' unit='MiB'/>
<cache id='1' level='3' type='both' size='1' unit='MiB'/>
</cachetune>
</cputune>
...
error: unsupported configuration: cachetune is only supported for KVM domains
Failed. Try again? [y,n,i,f,?]:
The error info raised, which is expected. So move this bug to be verified.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2018:3113 |
Description of problem: cachetune work not well with TCG guest Version-Release number of selected component (if applicable): libvirt-3.9.0-11.el7.x86_64 How reproducible: 100% Steps to Reproduce: 1. prepare a TCG guest with cachetune: <domain type='qemu'> <name>vm1</name> <uuid>f98741e7-ddad-4be1-82c0-0ae3655d1c25</uuid> <memory unit='KiB'>1024000</memory> <currentMemory unit='KiB'>1024000</currentMemory> <vcpu placement='static' cpuset='0-2' current='2'>4</vcpu> <cputune> <cachetune vcpus='0'> <cache id='0' level='3' type='both' size='1' unit='MiB'/> <cache id='1' level='3' type='both' size='2' unit='MiB'/> </cachetune> <cachetune vcpus='1'> <cache id='0' level='3' type='both' size='2' unit='MiB'/> <cache id='1' level='3' type='both' size='1' unit='MiB'/> </cachetune> <cachetune vcpus='3'> <cache id='0' level='3' type='both' size='1' unit='MiB'/> <cache id='1' level='3' type='both' size='1' unit='MiB'/> </cachetune> </cputune> 2. start guest: # virsh start vm1 Domain vm1 started 3. check the resctrl tasks binding status, and there is no task id in these dir: # cat /sys/fs/resctrl/qemu-5-vm1-vcpus_0/tasks # cat /sys/fs/resctrl/qemu-5-vm1-vcpus_1/tasks # cat /sys/fs/resctrl/qemu-5-vm1-vcpus_3/tasks Actual results: Libvirt create 3 dir for vcpus 0,1,3, but doesn't set the cpu thread in the tasks, and also TCG only have one thread for all cpus, libvirt cannot put each vcpu in these 3 dir Expected results: 1. report error with machine type is qemu: error: operation failed: Virt type 'qemu' does not support cachetune or 2. allow put all vcpus in one group Additional info: