perf/x86: Avoid touching LBR_TOS MSR for Arch LBR
stable inclusion from stable-5.10.40 commit 075becedce372422239a39488adddcb9f6334d50 bugzilla: 51882 CVE: NA -------------------------------- [ Upstream commit 3317c26a ] The Architecture LBR does not have MSR_LBR_TOS (0x000001c9). In a guest that should support Architecture LBR, check_msr() will be a non-related check for the architecture MSR 0x0 (IA32_P5_MC_ADDR) that is also not supported by KVM. The failure will cause x86_pmu.lbr_nr = 0, thereby preventing the initialization of the guest Arch LBR. Fix it by avoiding this extraneous check in intel_pmu_init() for Arch LBR. Fixes: 47125db2 ("perf/x86/intel/lbr: Support Architectural LBR") Signed-off-by:Like Xu <like.xu@linux.intel.com> [peterz: simpler still] Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210430052247.3079672-1-like.xu@linux.intel.com Signed-off-by:
Sasha Levin <sashal@kernel.org> Signed-off-by:
Chen Jun <chenjun102@huawei.com> Acked-by:
Weilong Chen <chenweilong@huawei.com> Signed-off-by:
Zheng Zengkai <zhengzengkai@huawei.com>
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