Kernel 7.0.x - Windows VMs freezing with cpu high 60-70%, newer cpus?

G

glaeken2

Member
Jun 7, 2023
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Hello!

I encountered a problem with kernels 7.0.x

Windows VMs (mostly win10, but also win11) can randomly freeze, with cpu usage about 60-70%.
This happens only on newer (faster?) cpus, to be exact: i7-13 gen and i9-12 gen
I don't observe this behavior on any older hardware which spans from multiple types of xeons to i5-7400, i7-6700, etc etc.

What is troubling - there is nothing in logs, like it never happened. Only guest agent ping timeouts.
Can't strace kvm process for now because I have to revert to kernel 6.17.

I used cpu-affinity on those machines to place vms on p-cored and e-cores respectively, so I removed it - didn't help.
Qemu machine versions are set to 10.1, all virtio drivers are the newest possible - didn't help.
Machine type set to i440fx, i don't know if it happens on q35.

This is a preliminary report because I can't reproduce this on demand to strace the kvm process.
 
reggyralfs said:
Hi @glaeken2

Did you ever find the solution to this one? I have exactly the same issue.
Click to expand...
Nope.
I tried some tracing, but nothing conclusive. One variable is 100% sure: kernel 6.x works, kernel 7.x doesn't.
Looks like a spinlock in windows kernel maybe?

Current verdict: inconclusive

Probable vectors: p-cores + e-cores, iommu, hugepages?
Gen 12 and gen 13 affected. Gen 7 not affected. Older xeons not affected.
Nothing in logs anywhere. I suspect only heavy kvm tracing will reveal anything (can't trace there unfortunately)


Factors NOT having any influence so far: machine type (i440fx and q35 both behave the same), cpu type (host/emulated), memory amount, windows version, updates
 
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