Bug 2137804

Summary:	Inconsistent error msg prompts when setting inexistent nodeset with restrictive numa tuning mode
Product:	Red Hat Enterprise Linux 9	Reporter:	liang cong <lcong>
Component:	libvirt	Assignee:	khanicov
libvirt sub component:	General	QA Contact:	liang cong <lcong>
Status:	CLOSED DUPLICATE	Docs Contact:
Severity:	low
Priority:	medium	CC:	abologna, lmen, mprivozn, virt-maint, xuzhang
Version:	9.1	Keywords:	Triaged
Target Milestone:	rc
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Hardware:	Unspecified
OS:	Unspecified
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Last Closed:	2023-01-16 10:50:47 UTC	Type:	Bug
Regression:	---	Mount Type:	---
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Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Description liang cong 2022-10-26 09:29:46 UTC

Description of problem:
Inconsistent error msg prompts when setting inexistent nodeset with restrictive numa tuning mode

Version-Release number of selected component (if applicable):
# rpm -q libvirt qemu-kvm
libvirt-8.5.0-7.el9_1.x86_64
qemu-kvm-7.0.0-13.el9.x86_64

How reproducible:
100%

Steps to Reproduce:
1.There are 2 numa nodes on host:
# numactl --hard
available: 2 nodes (0-1)
node 0 cpus: 0 1
node 0 size: 3671 MB
node 0 free: 1731 MB
node 1 cpus: 2 3
node 1 size: 4020 MB
node 1 free: 2215 MB
node distances:
node   0   1 
  0:  10  20 
  1:  20  10 

2.Set numa tuning with restrictive mode and inexistent numa nodeset 2
<numatune>
<memory mode='restrictive' nodeset='2'/>
</numatune>

3.Start the guest vm
# virsh start vm1
error: Failed to start domain 'vm1'
error: Invalid value '2' for 'cpuset.mems': Invalid argument

Actual results:
Error msg prompts:
error: Invalid value '2' for 'cpuset.mems': Invalid argument


Expected results:
If setting other numa tuning mode like "" then the error msg is:
error: unsupported configuration: NUMA node 2 is unavailable

The error msg should keep consistent. 


Additional info:
If setting numa topology like:
<numa>
   <cell id="0" cpus="0-1" memory="2097152" unit="KiB"/>
</numa>
then the error msg is consistent as "error: unsupported configuration: NUMA node 2 is unavailable", no matter what mode is set.

Comment 1 liang cong 2022-10-26 09:43:22 UTC

Add some info:
If setting other numa tuning mode like "preferred", "strict" or "interleave" then the error msg is:
error: unsupported configuration: NUMA node 2 is unavailable

Comment 2 Michal Privoznik 2022-10-26 09:47:36 UTC

This is because the check for host NUMA nodes presence is skipped in qemuBuildMemoryBackendProps() for VIR_DOMAIN_NUMATUNE_MEM_RESTRICTIVE and then the code proceeds to qemuProcessSetupPid() where the nodeset is set directly in CGroups, hence the difference in error messages.

Comment 3 Andrea Bolognani 2023-01-16 10:50:47 UTC


*** This bug has been marked as a duplicate of bug 2156289 ***