From f19063b1ca058b3971d6883b5ec45955b7f53f9c Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 9 Nov 2023 18:28:54 -0800 Subject: KVM: x86/pmu: Snapshot event selectors that KVM emulates in software Snapshot the event selectors for the events that KVM emulates in software, which is currently instructions retired and branch instructions retired. The event selectors a tied to the underlying CPU, i.e. are constant for a given platform even though perf doesn't manage the mappings as such. Getting the event selectors from perf isn't exactly cheap, especially if mitigations are enabled, as at least one indirect call is involved. Snapshot the values in KVM instead of optimizing perf as working with the raw event selectors will be required if KVM ever wants to emulate events that aren't part of perf's uABI, i.e. that don't have an "enum perf_hw_id" entry. Link: https://lore.kernel.org/r/20231110022857.1273836-8-seanjc@google.com Signed-off-by: Sean Christopherson --- arch/x86/kvm/x86.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/x86/kvm/x86.c') diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index cbee277254f0..a30df9f8d9d5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8903,7 +8903,7 @@ int kvm_skip_emulated_instruction(struct kvm_vcpu *vcpu) if (unlikely(!r)) return 0; - kvm_pmu_trigger_event(vcpu, PERF_COUNT_HW_INSTRUCTIONS); + kvm_pmu_trigger_event(vcpu, kvm_pmu_eventsel.INSTRUCTIONS_RETIRED); /* * rflags is the old, "raw" value of the flags. The new value has @@ -9216,9 +9216,9 @@ writeback: */ if (!ctxt->have_exception || exception_type(ctxt->exception.vector) == EXCPT_TRAP) { - kvm_pmu_trigger_event(vcpu, PERF_COUNT_HW_INSTRUCTIONS); + kvm_pmu_trigger_event(vcpu, kvm_pmu_eventsel.INSTRUCTIONS_RETIRED); if (ctxt->is_branch) - kvm_pmu_trigger_event(vcpu, PERF_COUNT_HW_BRANCH_INSTRUCTIONS); + kvm_pmu_trigger_event(vcpu, kvm_pmu_eventsel.BRANCH_INSTRUCTIONS_RETIRED); kvm_rip_write(vcpu, ctxt->eip); if (r && (ctxt->tf || (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP))) r = kvm_vcpu_do_singlestep(vcpu); -- cgit v1.2.3