Bug 1485260
| Summary: | virsh vcpupin returns wrong info on large machine | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux Advanced Virtualization | Reporter: | chhu |
| Component: | libvirt | Assignee: | Virtualization Maintenance <virt-maint> |
| Status: | CLOSED ERRATA | QA Contact: | jiyan <jiyan> |
| Severity: | medium | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 8.0 | CC: | jdenemar, jsuchane, jtomko, lhuang, rbalakri, xuzhang, yafu, yalzhang |
| Target Milestone: | rc | Keywords: | Triaged |
| Target Release: | --- | ||
| Hardware: | x86_64 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | libvirt-6.0.0-1.el8 | Doc Type: | If docs needed, set a value |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2020-05-05 09:43:16 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: | |||
Fixed upstream by:
commit 51f9f80d350e633adf479c6a9b3c55f82ca9cbd4
Author: Allen, John <John.Allen>
CommitDate: 2019-04-25 10:18:48 +0200
Handle copying bitmaps to larger data buffers
If a bitmap of a shorter length than the data buffer is passed to
virBitmapToDataBuf, it will read off the end of the bitmap and copy junk
into the returned buffer. Add a check to only copy the length of the
bitmap to the buffer.
The problem can be observed after setting a vcpu affinity using the vcpupin
command on a system with a large number of cores:
# virsh vcpupin example_domain 0 0
# virsh vcpupin example_domain 0
VCPU CPU Affinity
---------------------------
0 0,192,197-198,202
Signed-off-by: John Allen <john.allen>
git describe: v5.2.0-360-g51f9f80d35 contains: v5.3.0-rc1~7
According to the patch, this bug seems to be same with Bug 1703159 - virsh vcpupin reports bogus affinities (RHEL-7.7) and Bug 1703160 - virsh vcpupin reports bogus affinities (RHEL-8.1.0) What is strange is that I can bot hit these issue on 5 versions before libvirt-6.0.0-1.el8. For example: libvirt-5.6.0-7.module+el8.2.0+4670+07fe2774.x86_64 Version: libvirt-5.6.0-7.module+el8.2.0+4670+07fe2774.x86_64 kernel-4.18.0-187.el8.x86_64 qemu-kvm-4.2.0-13.module+el8.2.0+5898+fb4bceae.x86_64 Steps: # virsh domstate test82 # virsh dumpxml test82 |grep vcpu <vcpu placement='static'>2</vcpu> # virsh start test82 Domain test82 started # virsh vcpupin test82 VCPU CPU Affinity ---------------------- 0 0-447 1 0-447 # virsh vcpupin test82 0 0 # virsh vcpupin test82 VCPU CPU Affinity ---------------------- 0 0 1 0-447 And in bug description: libvirt-3.2.0-14.el7_4.3.x86_64, which is for RHEL-7. So could you pls check this bug to see whether this problem still exists on RHEL-8.2.0AV? The patch was included in the upstream libvirt release v5.3.0, so even RHEL-AV-8.1.0 should be fixed already. SO according to the previous comment, I will mark this bug as 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/RHBA-2020:2017 |
Description of problem: Virsh vcpuin return wrong info on large machine Version-Release number of selected component (if applicable): libvirt-3.2.0-14.el7_4.3.x86_64 qemu-kvm-rhev-2.9.0-16.el7_4.5.x86_64 kernel: 3.10.0-693.2.1.el7.x86_64 How reproducible: 100% on large machine Steps to Reproduce: 1. Start a guest with 384 cpus: (without numa node, hugepage,cpupin part in xml) <vcpu placement='static'>384</vcpu> # virsh list --all Id Name State ---------------------------------------------------- 19 r7-4t running 2. Check the vcpupin of the guest # virsh vcpupin r7-4t VCPU: CPU Affinity ---------------------------------- 0: 0-359 1: 0-359 2: 0-359 ...... 280: 0-359 ...... 300: 0-359 ...... 3. Do vcpupin operations: # virsh vcpupin r7-4t 280 300-301 # virsh vcpupin r7-4t 300 330-331 4. Check the virsh vcpupin info, the info for vcpu280 is wrong. # virsh vcpupin r7-4t VCPU: CPU Affinity ---------------------------------- 0: 0-359 1: 0-359 2: 0-359 ...... 280: 300-301,320,322,325 ...... 300: 330-331 ...... 5. Check the guest xml is correct. # virsh dumpxml r7-4t <domain type='kvm' id='19'> <name>r7-4t</name> ...... <vcpu placement='static'>384</vcpu> <cputune> <vcpupin vcpu='280' cpuset='300-301'/> <vcpupin vcpu='300' cpuset='330-331'/> </cputune> ...... 6. Check the cgroup and taskset are correct. # cgget -g cpuset /machine.slice/machine-qemu\\x2d19\\x2dr7\\x2d4t.scope/vcpu280| grep cpuset.cpus cpuset.cpus: 300-301 # cat 185024/cpuset /machine.slice/machine-qemu\x2d19\x2dr7\x2d4t.scope/vcpu280 # taskset -c -p 185024 pid 185024's current affinity list: 300,301 Actual result: In step4, vcpupin return wrong info Expected result: In step4, vcpupin return the correct info Others: 1. numad service is not started.