Hi Aruna, Commit ae6012d72fa6 "x86/pkeys: Ensure updated PKRU value is XRSTOR'd" seems to be broken on some Zhaoxin/VIA processors. Specifically:
On Thu, 2025-04-24 at 16:24 +0800, Larry Wei wrote: > Thanks for your replying, the `Probe URL` of my laptop: > https://linux-hardware.org/?probe=58facb533d , and `cpuinfo` is: > > larry@zx2:~/Downloads$ sudo cat /proc/cpuinfo > processor : 0 > vendor_id : CentaurHauls > cpu family : 7 > model : 59 > model name : ZHAOXIN KaiXian KX-6000G/4@3.0GHz [...] > flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca > cmov pat pse36 clflush acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx > pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good nopl nonstop_tsc > cpuid aperfmperf pni pclmulqdq monitor vmx smx est tm2 ssse3 cx16 xtpr > pcid sse4_1 sse4_2 movbe popcnt tsc_deadline_timer aes xsave avx f16c > rdrand rng rng_en ace ace_en ace2 phe phe_en pmm pmm_en lahf_lm abm > 3dnowprefetch ibrs ibpb tpr_shadow ept vpid fsgsbase tsc_adjust bmi1 > smep bmi2 invpcid rdseed adx smap sha_ni xsaveopt dtherm hwp > hwp_act_window hwp_epp hwp_pkg_req vnmi umip pku ospke rdpid > arch_capabilities > vmx flags : vnmi invvpid ept_x_only ept_1gb tsc_offset vtpr mtf ept > vpid unrestricted_guest ple [...] Notice that this has the PKU and OSPKE features set, but *not* XGETBV1. Which means that xfeatures_in_use() should not be called (and will cause a #GP exception). (The full bug report log for this is at <https://bugs.debian.org/1103397>.) Is there some fallback that could be used in case XGETBV1 is not available? Or do we need a dependency X86_FEATURE_PKU -> X86_FEATURE_XGETBV1 in arch/x86/kernel/cpu/cpuid-deps.c, so that we disable protection keys in this CPU? > > Ben. -- Ben Hutchings Who are all these weirdos? - David Bowie, on joining IRC
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