Commit 283a5aa5 authored by Dapeng Mi's avatar Dapeng Mi Committed by Sean Christopherson
Browse files

KVM: x86/pmu: Handle emulated instruction for mediated vPMU 



Mediated vPMU needs to accumulate the emulated instructions into counter
and load the counter into HW at vm-entry.

Moreover, if the accumulation leads to counter overflow, KVM needs to
update GLOBAL_STATUS and inject PMI into guest as well.

Suggested-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarDapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: default avatarMingwei Zhang <mizhang@google.com>
Tested-by: default avatarXudong Hao <xudong.hao@intel.com>
Tested-by: default avatarManali Shukla <manali.shukla@amd.com>
Link: https://patch.msgid.link/20251206001720.468579-30-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent f7a65e58

arch/x86/kvm/pmu.c

+37 −2
Original line number Diff line number Diff line
@@ -1031,10 +1031,45 @@ void kvm_pmu_destroy(struct kvm_vcpu *vcpu) 
	kvm_pmu_reset(vcpu);

}



static bool pmc_is_pmi_enabled(struct kvm_pmc *pmc)

{

	u8 fixed_ctr_ctrl;



	if (pmc_is_gp(pmc))

		return pmc->eventsel & ARCH_PERFMON_EVENTSEL_INT;



	fixed_ctr_ctrl = fixed_ctrl_field(pmc_to_pmu(pmc)->fixed_ctr_ctrl,

					  pmc->idx - KVM_FIXED_PMC_BASE_IDX);

	return fixed_ctr_ctrl & INTEL_FIXED_0_ENABLE_PMI;

}



static void kvm_pmu_incr_counter(struct kvm_pmc *pmc)

{

	struct kvm_vcpu *vcpu = pmc->vcpu;



	/*

	 * For perf-based PMUs, accumulate software-emulated events separately

	 * from pmc->counter, as pmc->counter is offset by the count of the

	 * associated perf event. Request reprogramming, which will consult

	 * both emulated and hardware-generated events to detect overflow.

	 */

	if (!kvm_vcpu_has_mediated_pmu(vcpu)) {

		pmc->emulated_counter++;

		kvm_pmu_request_counter_reprogram(pmc);

		return;

	}



	/*

	 * For mediated PMUs, pmc->counter is updated when the vCPU's PMU is

	 * put, and will be loaded into hardware when the PMU is loaded. Simply

	 * increment the counter and signal overflow if it wraps to zero.

	 */

	pmc->counter = (pmc->counter + 1) & pmc_bitmask(pmc);

	if (!pmc->counter) {

		pmc_to_pmu(pmc)->global_status |= BIT_ULL(pmc->idx);

		if (pmc_is_pmi_enabled(pmc))

			kvm_make_request(KVM_REQ_PMI, vcpu);

	}

}



static inline bool cpl_is_matched(struct kvm_pmc *pmc)