[PATCH] KVM: x86/pmu: Move Intel PMU global MSRs to intel_is_valid_msr()

[Jim Mattson <jmattson@google.com>]

Commit c85cdc1cc1ea ("KVM: x86/pmu: Move handling PERF_GLOBAL_CTRL and
friends to common x86") moved the existence check for the following Intel
PMU MSRs to kvm_pmu_is_valid_msr():
 - MSR_CORE_PERF_GLOBAL_STATUS
 - MSR_CORE_PERF_GLOBAL_CTRL
 - MSR_CORE_PERF_GLOBAL_OVF_CTRL

That commit deemed these MSRs valid whenever pmu->version > 1. It intended
to share the check with AMD PerfMonV2 because both vendor implementations
require version 2 or greater for global PMU controls.  However, as noted in
the commit message, AMD uses different MSR indices for its global PMU
registers.

Commit 4a2771895ca6 ("KVM: x86/svm/pmu: Add AMD PerfMonV2 support")
subsequently added AMD PerfMonV2 support and set pmu->version = 2.  Because
kvm_pmu_is_valid_msr() validated the Intel MSRs whenever pmu->version > 1,
KVM incorrectly permitted AMD guests with PerfMonV2 to access these Intel
MSRs without a #GP.

Move the validation of these Intel MSRs to intel_is_valid_msr() and remove
the common switch statement from kvm_pmu_is_valid_msr(). AMD already
validates its own global PMU MSRs in amd_is_valid_msr().

Fixes: 4a2771895ca6 ("KVM: x86/svm/pmu: Add AMD PerfMonV2 support")
Signed-off-by: Jim Mattson <jmattson@google.com>
---
 arch/x86/kvm/pmu.c           | 8 --------
 arch/x86/kvm/vmx/pmu_intel.c | 3 +++
 2 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index a7d60c8785cd..d2fd47ee5ec8 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -823,14 +823,6 @@ void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu)
 
 bool kvm_pmu_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
 {
-	switch (msr) {
-	case MSR_CORE_PERF_GLOBAL_STATUS:
-	case MSR_CORE_PERF_GLOBAL_CTRL:
-	case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
-		return kvm_pmu_has_perf_global_ctrl(vcpu_to_pmu(vcpu));
-	default:
-		break;
-	}
 	return kvm_pmu_call(msr_idx_to_pmc)(vcpu, msr) ||
 	       kvm_pmu_call(is_valid_msr)(vcpu, msr);
 }
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index bfa8612fb450..70a8c4816135 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -187,6 +187,9 @@ static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
 	int ret;
 
 	switch (msr) {
+	case MSR_CORE_PERF_GLOBAL_STATUS:
+	case MSR_CORE_PERF_GLOBAL_CTRL:
+	case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
 	case MSR_CORE_PERF_FIXED_CTR_CTRL:
 		return kvm_pmu_has_perf_global_ctrl(pmu);
 	case MSR_IA32_PEBS_ENABLE:
-- 
2.55.0.970.g62bdec98f9-goog