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

[ Upstream commit 0e6f467ee28ec97f68c7b74e35ec1601bb1368a7 ]

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

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 58ead7db71a312764b56d9f242e84820239eeb93..952aebd0a8a34fa750993a3d6b7b626be31192a0 100644 (file)
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -282,20 +282,16 @@ int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data)
 {
        bool fast_mode = idx & (1u << 31);
        struct kvm_pmc *pmc;
-       u64 ctr_val;
+       u64 mask = fast_mode ? ~0u : ~0ull;
 
        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;
 }
 

diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index ba8898e1a8542c31caaabeccc3e5b1c99f1efadd..22dff661145a1bcbf5996b7cb0c1fba660a5859e 100644 (file)
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -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);

diff --git a/arch/x86/kvm/pmu_amd.c b/arch/x86/kvm/pmu_amd.c
index 1495a735b38e757ea3d01e6716888d55cf8a84b7..41dff881e0f03d4c3adca38b5da9743e0d5f6524 100644 (file)
--- a/arch/x86/kvm/pmu_amd.c
+++ b/arch/x86/kvm/pmu_amd.c
@@ -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;

diff --git a/arch/x86/kvm/pmu_intel.c b/arch/x86/kvm/pmu_intel.c
index 5ab4a364348e3c10987c33203be4ff6fa97e1e73..ad7ea81fbfbf648f6fd18fbbc7cc431acd9c9256 100644 (file)
--- a/arch/x86/kvm/pmu_intel.c
+++ b/arch/x86/kvm/pmu_intel.c
@@ -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;