As can be seen here (https://launchpad.net/~mwhudson/+archive/ubuntu/devirt/+build/22621733), elf/tst-cpu-features-cpuinfo fails on the current (fairly new) launchpad builders. The failure is: Checking HAS_CPU_FEATURE (WBNOINVD): HAS_CPU_FEATURE (WBNOINVD): 1 cpuinfo (wbnoinvd): 0 *** failure *** /proc/cpuinfo is: processor : 0 vendor_id : AuthenticAMD cpu family : 23 model : 49 model name : AMD EPYC-Rome Processor stepping : 0 microcode : 0x1000065 cpu MHz : 2499.998 cache size : 512 KB physical id : 0 siblings : 1 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 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 syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm rep_good nopl xtopology cpuid extd_apicid tsc_known_freq pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx f16c rdrand hypervisor lahf_lm svm cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw topoext perfctr_core ibpb stibp vmmcall fsgsbase bmi1 avx2 smep bmi2 rdseed adx smap clflushopt clwb sha_ni xsaveopt xsavec xgetbv1 xsaves clzero xsaveerptr arat npt nrip_save umip rdpid bugs : sysret_ss_attrs spectre_v1 spectre_v2 spec_store_bypass bogomips : 4999.99 TLB size : 1024 4K pages clflush size : 64 cache_alignment : 64 address sizes : 40 bits physical, 48 bits virtual power management:
I guess it's related to Linux kernel version. I likely have the very same CPU: $ cat /proc/cpuinfo | head -n100 processor : 0 vendor_id : AuthenticAMD cpu family : 23 model : 49 model name : AMD EPYC 7702 64-Core Processor stepping : 0 microcode : 0x8301025 cpu MHz : 3343.026 cache size : 512 KB physical id : 0 siblings : 128 core id : 0 cpu cores : 64 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 16 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 rep_good nopl nonstop_tsc cpuid extd_apicid aperfmperf 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 xsaves 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 umip rdpid overflow_recov succor smca bugs : sysret_ss_attrs spectre_v1 spectre_v2 spec_store_bypass bogomips : 3992.68 TLB size : 3072 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] $ uname -a Linux benzen 5.12.9-1-default #1 SMP Thu Jun 3 07:44:58 UTC 2021 (f17eb01) x86_64 x86_64 x86_64 GNU/Linux And as seen, 'wbnoinvd' is present in the flags.