Processors Profile

[OD3UNICRON]

I have a AMD EPYC 7282, When I select Processor Type EPYC-Rome or EPYC-Rome-v2, then I go to my console and start, it wont start, it only work if i select host or EPYC.

 

[jsterr]

Just tested, error says on both cpu profiles:

()
kvm: warning: host doesn't support requested feature: CPUID.0DH:EAX.xsaves [bit 3]
kvm: Host doesn't support requested features
TASK ERROR: start failed: QEMU exited with code 1

@OD3UNICRON just in case you dont know, if possible using host profile would be best regarding performance and it also works in this case.

Seems like the cpu profile refers to a cpu function that is not available on rome cpus:

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 rep_good nopl nonstop_tsc cpuid extd_apicid aperfmperf rapl 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 ibs skinit wdt tce topoext perfctr_core perfctr_nb bpext perfctr_llc mwaitx cpb cat_l3 cdp_l3 hw_pstate ssbd mba ibrs ibpb stibp vmmcall fsgsbase bmi1 avx2 smep bmi2 cqm rdt_a rdseed adx smap clflushopt clwb sha_ni xsaveopt xsavec xgetbv1 cqm_llc cqm_occup_llc cqm_mbm_total cqm_mbm_local clzero irperf xsaveerptr rdpru wbnoinvd amd_ppin arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold avic v_vmsave_vmload vgif v_spec_ctrl umip rdpid overflow_recov succor smca sev sev_es

Edit: Seems like this is because of disabling the support for xsaves. see: https://lore.kernel.org/all/20230307174643.1240184-1-andrew.cooper3@citrix.com/

and the quote:

+ /*
+ * Work around Erratum 1386. The XSAVES instruction malfunctions in
+ * certain circumstances on Zen1/2 uarch, and not all parts have had
+ * updated microcode at the time of writing (March 2023).
+ *
+ * Affected parts all have no supervisor XSAVE states, meaning that
+ * the XSAVEC instruction (which works fine) is equivelent.
+ */
+ if (c->x86 == 0x17)
+ clear_cpu_cap(c, X86_FEATURE_XSAVES);

 

[jsterr]

See https://forum.proxmox.com/threads/cant-use-epyc-rome-cpu-after-update.125336/#post-547510 for a solution/workaround and additional information why this happens.