Messages in this thread | | | From | Maxim Levitsky <> | Subject | [PATCH 0/4] x86: cpuid: improve support for broken CPUID configurations | Date | Wed, 22 Jun 2022 17:48:16 +0300 |
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This patch series aims to harden the cpuid code against the case when the hypervisor exposes a broken CPUID configuration to the guest, in the form of having a feature disabled but not features that depend on it.
This is the more generic way to fix kernel panic in aes-ni kernel driver, which was triggered by CPUID configuration in which AVX is disabled but not AVX2.
https://lore.kernel.org/all/20211103145231.GA4485@gondor.apana.org.au/T/
This was tested by booting a guest with AVX disabled and not AVX2, and observing that both a warning is now printed in dmesg, and that avx2 is gone from /proc/cpuinfo.
Best regards, Maxim Levitsky
Maxim Levitsky (4): perf/x86/intel/lbr: use setup_clear_cpu_cap instead of clear_cpu_cap x86/cpuid: refactor setup_clear_cpu_cap/clear_feature x86/cpuid: move filter_cpuid_features to cpuid-deps.c x86/cpuid: check for dependencies violations in CPUID and attempt to fix them
arch/x86/events/intel/lbr.c | 2 +- arch/x86/include/asm/cpufeature.h | 1 + arch/x86/kernel/cpu/common.c | 50 +----------------- arch/x86/kernel/cpu/cpuid-deps.c | 84 +++++++++++++++++++++++++++---- 4 files changed, 78 insertions(+), 59 deletions(-)
-- 2.26.3
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