Messages in this thread Patch in this message | | | From | Like Xu <> | Subject | [PATCH] KVM: x86/pt: Do not inject TraceToPAPMI when guest PT isn't supported | Date | Fri, 14 May 2021 16:44:36 +0800 |
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When a PT perf user is running in system-wide mode on the host, the guest (w/ pt_mode=0) will warn about anonymous NMIs from kvm_handle_intel_pt_intr():
[ 18.126444] Uhhuh. NMI received for unknown reason 10 on CPU 0. [ 18.126447] Do you have a strange power saving mode enabled? [ 18.126448] Dazed and confused, but trying to continue
In this case, these PMIs should be handled by the host PT handler(). When PT is used in guest-only mode, it's harmless to call host handler.
Fix: 8479e04e7d("KVM: x86: Inject PMI for KVM guest") Signed-off-by: Like Xu <like.xu@linux.intel.com> --- arch/x86/events/intel/core.c | 3 +-- arch/x86/kvm/x86.c | 3 +++ 2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 2521d03de5e0..2f09eb0853de 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -2853,8 +2853,7 @@ static int handle_pmi_common(struct pt_regs *regs, u64 status) if (unlikely(perf_guest_cbs && perf_guest_cbs->is_in_guest() && perf_guest_cbs->handle_intel_pt_intr)) perf_guest_cbs->handle_intel_pt_intr(); - else - intel_pt_interrupt(); + intel_pt_interrupt(); } /* diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 6529e2023147..6660f3948cea 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8087,6 +8087,9 @@ static void kvm_handle_intel_pt_intr(void) { struct kvm_vcpu *vcpu = __this_cpu_read(current_vcpu); + if (!guest_cpuid_has(vcpu, X86_FEATURE_INTEL_PT)) + return; + kvm_make_request(KVM_REQ_PMI, vcpu); __set_bit(MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI_BIT, (unsigned long *)&vcpu->arch.pmu.global_status); -- 2.31.1
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