KVM: x86/pmu: Don't ignore bits 31:30 for RDPMC index on AMD

Stop stripping bits 31:30 prior to validating/consuming the RDPMC index on
AMD.  Per the APM's documentation of RDPMC, *values* greater than 27 are
reserved.  The behavior of upper bits being flags is firmly Intel-only.

Fixes: ca724305a2b0 ("KVM: x86/vPMU: Implement AMD vPMU code for KVM")
Tested-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Link: https://lore.kernel.org/r/20240109230250.424295-7-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c
index 1475d47c821c4e6e436009962d662efbd8e13dec..1fafc46f61c9889581cfc7920dfa11a8a3da7548 100644 (file)
--- a/arch/x86/kvm/svm/pmu.c
+++ b/arch/x86/kvm/svm/pmu.c
@@ -77,8 +77,6 @@ static bool amd_is_valid_rdpmc_ecx(struct kvm_vcpu *vcpu, unsigned int idx)
 {
        struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 
-       idx &= ~(3u << 30);
-
        return idx < pmu->nr_arch_gp_counters;
 }
 
@@ -86,7 +84,7 @@ static bool amd_is_valid_rdpmc_ecx(struct kvm_vcpu *vcpu, unsigned int idx)
 static struct kvm_pmc *amd_rdpmc_ecx_to_pmc(struct kvm_vcpu *vcpu,
        unsigned int idx, u64 *mask)
 {
-       return amd_pmc_idx_to_pmc(vcpu_to_pmu(vcpu), idx & ~(3u << 30));
+       return amd_pmc_idx_to_pmc(vcpu_to_pmu(vcpu), idx);
 }
 
 static struct kvm_pmc *amd_msr_idx_to_pmc(struct kvm_vcpu *vcpu, u32 msr)