Commit 0e6f467e authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: x86/pmu: mask the result of rdpmc according to the width of the counters 



This patch will simplify the changes in the next, by enforcing the
masking of the counters to RDPMC and RDMSR.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent a80c4ec1

arch/x86/kvm/pmu.c

+3 −7
Original line number Diff line number Diff line
@@ -283,7 +283,7 @@ int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data) 
	bool fast_mode = idx & (1u << 31);

	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);

	struct kvm_pmc *pmc;

	u64 ctr_val;

	u64 mask = fast_mode ? ~0u : ~0ull;



	if (!pmu->version)

		return 1;
@@ -291,15 +291,11 @@ int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data) 
	if (is_vmware_backdoor_pmc(idx))

		return kvm_pmu_rdpmc_vmware(vcpu, idx, data);



	pmc = kvm_x86_ops->pmu_ops->msr_idx_to_pmc(vcpu, idx);

	pmc = kvm_x86_ops->pmu_ops->msr_idx_to_pmc(vcpu, idx, &mask);

	if (!pmc)

		return 1;



	ctr_val = pmc_read_counter(pmc);

	if (fast_mode)

		ctr_val = (u32)ctr_val;



	*data = ctr_val;

	*data = pmc_read_counter(pmc) & mask;

	return 0;

}

arch/x86/kvm/pmu.h

+2 −1
Original line number Diff line number Diff line
@@ -25,7 +25,8 @@ struct kvm_pmu_ops { 
	unsigned (*find_fixed_event)(int idx);

	bool (*pmc_is_enabled)(struct kvm_pmc *pmc);

	struct kvm_pmc *(*pmc_idx_to_pmc)(struct kvm_pmu *pmu, int pmc_idx);

	struct kvm_pmc *(*msr_idx_to_pmc)(struct kvm_vcpu *vcpu, unsigned idx);

	struct kvm_pmc *(*msr_idx_to_pmc)(struct kvm_vcpu *vcpu, unsigned idx,

					  u64 *mask);

	int (*is_valid_msr_idx)(struct kvm_vcpu *vcpu, unsigned idx);

	bool (*is_valid_msr)(struct kvm_vcpu *vcpu, u32 msr);

	int (*get_msr)(struct kvm_vcpu *vcpu, u32 msr, u64 *data);

arch/x86/kvm/pmu_amd.c

+1 −1
Original line number Diff line number Diff line
@@ -186,7 +186,7 @@ static int amd_is_valid_msr_idx(struct kvm_vcpu *vcpu, unsigned idx) 
}



/* idx is the ECX register of RDPMC instruction */

static struct kvm_pmc *amd_msr_idx_to_pmc(struct kvm_vcpu *vcpu, unsigned idx)

static struct kvm_pmc *amd_msr_idx_to_pmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *mask)

{

	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);

	struct kvm_pmc *counters;

arch/x86/kvm/vmx/pmu_intel.c

+9 −4
Original line number Diff line number Diff line
@@ -126,7 +126,7 @@ static int intel_is_valid_msr_idx(struct kvm_vcpu *vcpu, unsigned idx) 
}



static struct kvm_pmc *intel_msr_idx_to_pmc(struct kvm_vcpu *vcpu,

					    unsigned idx)

					    unsigned idx, u64 *mask)

{

	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);

	bool fixed = idx & (1u << 30);
@@ -138,6 +138,7 @@ static struct kvm_pmc *intel_msr_idx_to_pmc(struct kvm_vcpu *vcpu, 
	if (fixed && idx >= pmu->nr_arch_fixed_counters)

		return NULL;

	counters = fixed ? pmu->fixed_counters : pmu->gp_counters;

	*mask &= pmu->counter_bitmask[fixed ? KVM_PMC_FIXED : KVM_PMC_GP];



	return &counters[idx];

}
@@ -183,9 +184,13 @@ static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data) 
		*data = pmu->global_ovf_ctrl;

		return 0;

	default:

		if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) ||

		    (pmc = get_fixed_pmc(pmu, msr))) {

			*data = pmc_read_counter(pmc);

		if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0))) {

			u64 val = pmc_read_counter(pmc);

			*data = val & pmu->counter_bitmask[KVM_PMC_GP];

			return 0;

		} else if ((pmc = get_fixed_pmc(pmu, msr))) {

			u64 val = pmc_read_counter(pmc);

			*data = val & pmu->counter_bitmask[KVM_PMC_FIXED];

			return 0;

		} else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) {

			*data = pmc->eventsel;