@jwp can you explain or link some documentation on how I can expose those feature one by one ? I’m not sure how to do that, but basically using kvm64, I’m loosing the AMD SEV feature which makes me unable to boot a Linux VM and inside that Linux VM boot Windows for instance.
EDIT :
Running virsh capabilities showed me most of the flags, I think but I’m still not sure where I should insert them in the XML, most likely inside <cpu>....</cpu>
Here is the list :
<feature name='ht'/>
<feature name='monitor'/>
<feature name='x2apic'/>
<feature name='osxsave'/>
<feature name='erms'/>
<feature name='invpcid'/>
<feature name='cmt'/>
<feature name='avx512f'/>
<feature name='avx512dq'/>
<feature name='avx512ifma'/>
<feature name='avx512cd'/>
<feature name='avx512bw'/>
<feature name='avx512vl'/>
<feature name='avx512vbmi'/>
<feature name='pku'/>
<feature name='ospke'/>
<feature name='avx512vbmi2'/>
<feature name='gfni'/>
<feature name='vaes'/>
<feature name='vpclmulqdq'/>
<feature name='avx512vnni'/>
<feature name='avx512bitalg'/>
<feature name='avx512-vpopcntdq'/>
<feature name='flush-l1d'/>
<feature name='avx512-bf16'/>
<feature name='xsaves'/>
<feature name='mbm_total'/>
<feature name='mbm_local'/>
<feature name='cmp_legacy'/>
<feature name='extapic'/>
<feature name='ibs'/>
<feature name='skinit'/>
<feature name='wdt'/>
<feature name='tce'/>
<feature name='topoext'/>
<feature name='perfctr_nb'/>
<feature name='invtsc'/>
<feature name='ibrs'/>
<feature name='stibp-always-on'/>
<feature name='amd-ssbd'/>
<feature name='amd-psfd'/>
<feature name='lbrv'/>
<feature name='svm-lock'/>
<feature name='tsc-scale'/>
<feature name='vmcb-clean'/>
<feature name='flushbyasid'/>
<feature name='decodeassists'/>
<feature name='pause-filter'/>
<feature name='pfthreshold'/>
<feature name='v-vmsave-vmload'/>
<feature name='vgif'/>
<feature name='vnmi'/>
<feature name='svme-addr-chk'/>
<feature name='no-nested-data-bp'/>
<feature name='lfence-always-serializing'/>
<feature name='null-sel-clr-base'/>
<feature name='auto-ibrs'/>
EDIT 2: I think I found the way how to expose feature I think, just check the flags in lscpu and then add the one you wish to expose in the <cpu> :
<cpu mode="custom" match="exact" check="none">
<model fallback="allow">kvm64</model>
<feature policy="require" name="ibpb"/>
<feature policy="require" name="spec-ctrl"/>
<feature policy="require" name="ssbd"/>
<feature policy="require" name="virt-ssbd"/>
<feature policy="require" name="svm"/>
<feature policy="require" name="svm-lock"/>
</cpu>
Thank you for putting so much effort into this!