[Starlingx-discuss] WG: cpu mode

[von Hoesslin, Volker]

i have set "host-passthrough" in "/etc/nova/nova.conf"

=================================
[DEFAULT]
libvirt_cpu_mode = host-passthrough

[libvirt]
cpu_mode = host-passthrough
=================================

and restart nove service: 
# service nova-compute restart

for now it works! "lscpu" on guest os shows me the AMD EPIC with all features, very nice. but after reboot the compute-node, the auto-config script change this setting back to "none":

[libvirt]
cpu_mode = none

and passthrough did not work anymore :( so how can i prevent this auto-config or define my new config as persistent?

volker...
________________________________________
Von: Michel Thebeau [michel.thebeau at windriver.com]
Gesendet: Freitag, 18. Januar 2019 17:07
An: von Hoesslin, Volker; starlingx-discuss at lists.starlingx.io
Betreff: Re: [Starlingx-discuss] cpu mode

Hi Volker,

The output you listed here lists the values accepted by openstack
flavor set command.

Did you try "Passthrough"?

I'm asking internally about cpu model support and I'll respond if I
hear anything interesting.

M


On Thu, 2019-01-17 at 16:23 +0000, von Hoesslin, Volker wrote:
> it is impossible to set a EPIC (or any other AMD) as guest CPU?
>
> $ openstack flavor set --property hw:cpu_model=EPYC-IBPB 76609f7b-
> f0c7-48ca-8c8a-f78481e62cd4
> Failed to set flavor property: Invalid hw:cpu_model 'EPYC-IBPB', must
> be one of: Passthrough, Conroe, Penryn, Nehalem, Westmere,
> SandyBridge, IvyBridge, Haswell, Broadwell-noTSX, Broadwell, Skylake-
> Client, Skylake-Server. (HTTP 400) (Request-ID: req-2fda19cc-8e0e-
> 4be8-a8ea-b58fc00358ce)
> Command Failed: One or more of the operations failed
>
> but my compute node seems to support EPIC CPUs?
>
> cat /usr/share/libvirt/cpu_map/x86_EPYC-IBRS.xml
>
> <cpus>
>   <model name='EPYC-IBPB'>
>     <signature family='23' model='1'/>
>     <vendor name='AMD'/>
>     <feature name='3dnowprefetch'/>
>  ....
>     <feature name='xsavec'/>
>     <feature name='xsaveopt'/>
>   </model>
> </cpus>
>
> some tips for me how to handle this?
>
> volker...
>
> Von: von Hoesslin, Volker [Volker.Hoesslin at swsn.de]
> Gesendet: Donnerstag, 17. Januar 2019 15:50
> An: starlingx-discuss at lists.starlingx.io
> Betreff: [Starlingx-discuss] cpu mode
>
> hi,
> my setup has two computes nodes, every node has a dual AMD EPYC 7601
> CPU config. how can i bring all the CPU features (AES, SSSE3, ...) to
> the guest VMs. i have tryed with some flavor-metadata but nothing
> realy helps, the VMs getting just a little subset of cpu-features.
> some investigations to the kvm-settings hit me to the facts that my
> nova config has "cpu_model=none" !? how can i fix that and bring my
> AMD EPIC CPU to my nova-config?!
>
> here is the host /proc/cpuinfo
>
> processor       : 127
> vendor_id       : AuthenticAMD
> cpu family      : 23
> model           : 1
> model name      : AMD EPYC 7601 32-Core Processor
> stepping        : 2
> microcode       : 0x8001227
> cpu MHz         : 1200.000
> cache size      : 512 KB
> physical id     : 1
> siblings        : 64
> core id         : 31
> cpu cores       : 32
> apicid          : 127
> initial apicid  : 127
> fpu             : yes
> fpu_exception   : yes
> cpuid level     : 13
> wp              : yes
> flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr
> pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext
> fxsr_opt pdpe1gb rdtscp lm constant_tsc art rep_good nopl nonstop_tsc
> extd_apicid amd_dcm aperfmperf eagerfpu pni pclmulqdq monitor ssse3
> fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand lahf_lm
> cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch
> osvw skinit wdt tce topoext perfctr_core perfctr_nb bpext perfctr_l2
> cpb hw_pstate retpoline_amd ssbd ibpb vmmcall fsgsbase bmi1 avx2 smep
> bmi2 rdseed adx smap clflushopt sha_ni xsaveopt xsavec xgetbv1 clzero
> irperf xsaveerptr arat npt lbrv svm_lock nrip_save tsc_scale
> vmcb_clean flushbyasid decodeassists pausefilter pfthreshold avic
> v_vmsave_vmload vgif overflow_recov succor smca
> bogomips        : 4400.08
> TLB size        : 2560 4K pages
> clflush size    : 64
> cache_alignment : 64
> address sizes   : 48 bits physical, 48 bits virtual
> power management: ts ttp tm hwpstate cpb eff_freq_ro [13] [14]
>
> greez & thx,
> volker...
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