[pve-devel] [PATCH-SERIES v3 qemu-server/manager/common] add and set x86-64-v2 as default model for new vms and detect best cpumodel

DERUMIER, Alexandre alexandre.derumier at groupe-cyllene.com
Thu Jun 1 15:53:58 CEST 2023

> > 
> > What AMD CPUs did you try it on?
> > 
> epyc v2/v3 with last microcodes
> does it work with x86-64-v3 ?  (because the other patch of the series
> could autofind the best new model if it's working)

Looking at linux kernel code, they have some quirks based on cpu model
number && vendor

nehalem is .family = 6, .model = 26,

kvm64 is .family = 15, .model = 6

qemu64 is.family = 15, .model = 107,

maybe it could be interesting to test with adding flags from
qemu64/kvm4  to see if it's the same behaviour ?

from kvm64, xf86-64-v2 is

'+lahf_lm,+popcnt, +sse4.1,sse4.2, +ssse3'     (and optionnal +aes)

(and we already enable lahf_lm by default in QemuServer/CPUConfig.pm )

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