The following commit has been merged into the perf/urgent branch of tip: Commit-ID: 0fe39a3929ac7af980347814d552a734b51adacf Gitweb: https://git.kernel.org/tip/0fe39a3929ac7af980347814d552a734b51adacf Author: Wanpeng Li <wanpengli@xxxxxxxxxxx> AuthorDate: Fri, 05 Nov 2021 00:20:51 -07:00 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Thu, 11 Nov 2021 13:09:34 +01:00 perf/x86/lbr: Reset LBR_SELECT during vlbr reset lbr_select in kvm guest has residual data even if kvm guest is poweroff. We can get residual data in the next boot. Because lbr_select is not reset during kvm vlbr release. Let's reset LBR_SELECT during vlbr reset. Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/1636096851-36623-1-git-send-email-wanpengli@xxxxxxxxxxx --- arch/x86/events/intel/lbr.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c index 6b72e9b..8043213 100644 --- a/arch/x86/events/intel/lbr.c +++ b/arch/x86/events/intel/lbr.c @@ -265,6 +265,8 @@ void intel_pmu_lbr_reset(void) cpuc->last_task_ctx = NULL; cpuc->last_log_id = 0; + if (!static_cpu_has(X86_FEATURE_ARCH_LBR) && cpuc->lbr_select) + wrmsrl(MSR_LBR_SELECT, 0); } /*
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