Commit 46b18782 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: Keep a per-VM pointer to the default PMU 



As we are about to allow selection of the PMU exposed to a guest, start by
keeping track of the default one instead of only the PMU version.

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Signed-off-by: default avatarAlexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20220127161759.53553-4-alexandru.elisei@arm.com
parent 2093057a

arch/arm64/include/asm/kvm_host.h

+1 −1
Original line number Diff line number Diff line
@@ -129,7 +129,7 @@ struct kvm_arch { 
	 * up to 2^10 events (ARMv8.0) or 2^16 events (ARMv8.1+).

	 */

	unsigned long *pmu_filter;

	unsigned int pmuver;

	struct arm_pmu *arm_pmu;



	u8 pfr0_csv2;

	u8 pfr0_csv3;

arch/arm64/kvm/pmu-emul.c

+26 −16
Original line number Diff line number Diff line
@@ -24,7 +24,11 @@ static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc); 


static u32 kvm_pmu_event_mask(struct kvm *kvm)

{

	switch (kvm->arch.pmuver) {

	unsigned int pmuver;



	pmuver = kvm->arch.arm_pmu->pmuver;



	switch (pmuver) {

	case ID_AA64DFR0_PMUVER_8_0:

		return GENMASK(9, 0);

	case ID_AA64DFR0_PMUVER_8_1:
@@ -33,7 +37,7 @@ static u32 kvm_pmu_event_mask(struct kvm *kvm) 
	case ID_AA64DFR0_PMUVER_8_7:

		return GENMASK(15, 0);

	default:		/* Shouldn't be here, just for sanity */

		WARN_ONCE(1, "Unknown PMU version %d\n", kvm->arch.pmuver);

		WARN_ONCE(1, "Unknown PMU version %d\n", pmuver);

		return 0;

	}

}
@@ -600,6 +604,7 @@ static bool kvm_pmu_counter_is_enabled(struct kvm_vcpu *vcpu, u64 select_idx) 
 */

static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx)

{

	struct arm_pmu *arm_pmu = vcpu->kvm->arch.arm_pmu;

	struct kvm_pmu *pmu = &vcpu->arch.pmu;

	struct kvm_pmc *pmc;

	struct perf_event *event;
@@ -636,7 +641,7 @@ static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx) 
		return;



	memset(&attr, 0, sizeof(struct perf_event_attr));

	attr.type = PERF_TYPE_RAW;

	attr.type = arm_pmu->pmu.type;

	attr.size = sizeof(attr);

	attr.pinned = 1;

	attr.disabled = !kvm_pmu_counter_is_enabled(vcpu, pmc->idx);
@@ -750,12 +755,11 @@ void kvm_host_pmu_init(struct arm_pmu *pmu) 
		static_branch_enable(&kvm_arm_pmu_available);

}



static int kvm_pmu_probe_pmuver(void)

static struct arm_pmu *kvm_pmu_probe_armpmu(void)

{

	struct perf_event_attr attr = { };

	struct perf_event *event;

	struct arm_pmu *pmu;

	int pmuver = ID_AA64DFR0_PMUVER_IMP_DEF;

	struct arm_pmu *pmu = NULL;



	/*

	 * Create a dummy event that only counts user cycles. As we'll never
@@ -780,19 +784,20 @@ static int kvm_pmu_probe_pmuver(void) 
	if (IS_ERR(event)) {

		pr_err_once("kvm: pmu event creation failed %ld\n",

			    PTR_ERR(event));

		return ID_AA64DFR0_PMUVER_IMP_DEF;

		return NULL;

	}



	if (event->pmu) {

		pmu = to_arm_pmu(event->pmu);

		if (pmu->pmuver)

			pmuver = pmu->pmuver;

		if (pmu->pmuver == 0 ||

		    pmu->pmuver == ID_AA64DFR0_PMUVER_IMP_DEF)

			pmu = NULL;

	}



	perf_event_disable(event);

	perf_event_release_kernel(event);



	return pmuver;

	return pmu;

}



u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1)
@@ -810,7 +815,7 @@ u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1) 
		 * Don't advertise STALL_SLOT, as PMMIR_EL0 is handled

		 * as RAZ

		 */

		if (vcpu->kvm->arch.pmuver >= ID_AA64DFR0_PMUVER_8_4)

		if (vcpu->kvm->arch.arm_pmu->pmuver >= ID_AA64DFR0_PMUVER_8_4)

			val &= ~BIT_ULL(ARMV8_PMUV3_PERFCTR_STALL_SLOT - 32);

		base = 32;

	}
@@ -932,11 +937,16 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) 
	if (vcpu->arch.pmu.created)

		return -EBUSY;



	if (!vcpu->kvm->arch.pmuver)

		vcpu->kvm->arch.pmuver = kvm_pmu_probe_pmuver();



	if (vcpu->kvm->arch.pmuver == ID_AA64DFR0_PMUVER_IMP_DEF)

	mutex_lock(&kvm->lock);

	if (!kvm->arch.arm_pmu) {

		/* No PMU set, get the default one */

		kvm->arch.arm_pmu = kvm_pmu_probe_armpmu();

		if (!kvm->arch.arm_pmu) {

			mutex_unlock(&kvm->lock);

			return -ENODEV;

		}

	}

	mutex_unlock(&kvm->lock);



	switch (attr->attr) {

	case KVM_ARM_VCPU_PMU_V3_IRQ: {