CPU passthrough or selected CPU-flag add in.

finley

Member
Apr 21, 2020
5
1
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Hi, expert

I would like to add some special CPU flag to VM, since those flags are import for our work. Such as:

CPU flags of host:
fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc art arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid dca sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch cpuid_fault epb cat_l3 cdp_l3 invpcid_single intel_ppin ssbd mba ibrs ibpb stibp ibrs_enhanced tpr_shadow vnmi flexpriority ept vpid ept_ad fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid cqm mpx rdt_a avx512f avx512dq rdseed adx smap clflushopt clwb intel_pt avx512cd avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves cqm_llc cqm_occup_llc cqm_mbm_total cqm_mbm_local dtherm arat pln pts pku ospke avx512_vnni md_clear flush_l1d arch_capabilities

CPU flags of VM(host CPU type selected):
fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good nopl xtopology eagerfpu pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch invpcid_single ssbd ibrs ibpb stibp ibrs_enhanced fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec xgetbv1 arat umip pku ospke avx512_vnni md_clear spec_ctrl intel_stibp arch_capabilities

We need CPU flag of nonstop_tsc which was filtered out by PVE.

What's more, is there any possibility to passthrough some cores to VM? Since we would like to use SR-IOV in VM.

Thanks.
Finley.
 
1] add it in VM config (GUI if its possible, file if not)
2] if you want bind VM to CPU directly, this isnt possible from GUI yet, so file or command line
 
Hi, czechsys and avw

Thanks for your help. I will have a try and let's see the result.
 
Hello. I had a problem with a recent glibc needing AVX-AES

Fatal glibc error: CPU does not support x86-64-v2

This fixed it (passing +aes in GUI wasn't sufficient)

Thanks :)
 
Hello. I had a problem with a recent glibc needing AVX-AES

Fatal glibc error: CPU does not support x86-64-v2

This fixed it (passing +aes in GUI wasn't sufficient)

Thanks :)
Hi Bastien,

Good to hear that you managed to enable "CPU passthrough" ... Would you mind sharing details on how this could be done?

Thanks
 

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