1 files changed, 79 insertions, 13 deletions

diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index de1d9785c01f..27eb76e6b6a0 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -61,6 +61,7 @@ static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data)
 	int i;
 
 	pmu->fixed_ctr_ctrl = data;
+	pmu->fixed_ctr_ctrl_hw = data;
 	for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
 		u8 new_ctrl = fixed_ctrl_field(data, i);
 		u8 old_ctrl = fixed_ctrl_field(old_fixed_ctr_ctrl, i);
@@ -128,19 +129,6 @@ static struct kvm_pmc *intel_rdpmc_ecx_to_pmc(struct kvm_vcpu *vcpu,
 	return &counters[array_index_nospec(idx, num_counters)];
 }
 
-static inline u64 vcpu_get_perf_capabilities(struct kvm_vcpu *vcpu)
-{
-	if (!guest_cpu_cap_has(vcpu, X86_FEATURE_PDCM))
-		return 0;
-
-	return vcpu->arch.perf_capabilities;
-}
-
-static inline bool fw_writes_is_enabled(struct kvm_vcpu *vcpu)
-{
-	return (vcpu_get_perf_capabilities(vcpu) & PERF_CAP_FW_WRITES) != 0;
-}
-
 static inline struct kvm_pmc *get_fw_gp_pmc(struct kvm_pmu *pmu, u32 msr)
 {
 	if (!fw_writes_is_enabled(pmu_to_vcpu(pmu)))
@@ -443,6 +431,7 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 
 			if (data != pmc->eventsel) {
 				pmc->eventsel = data;
+				pmc->eventsel_hw = data;
 				kvm_pmu_request_counter_reprogram(pmc);
 			}
 			break;
@@ -767,6 +756,71 @@ void intel_pmu_cross_mapped_check(struct kvm_pmu *pmu)
 	}
 }
 
+static bool intel_pmu_is_mediated_pmu_supported(struct x86_pmu_capability *host_pmu)
+{
+	u64 host_perf_cap = 0;
+
+	if (boot_cpu_has(X86_FEATURE_PDCM))
+		rdmsrq(MSR_IA32_PERF_CAPABILITIES, host_perf_cap);
+
+	/*
+	 * Require v4+ for MSR_CORE_PERF_GLOBAL_STATUS_SET, and full-width
+	 * writes so that KVM can precisely load guest counter values.
+	 */
+	if (host_pmu->version < 4 || !(host_perf_cap & PERF_CAP_FW_WRITES))
+		return false;
+
+	/*
+	 * All CPUs that support a mediated PMU are expected to support loading
+	 * PERF_GLOBAL_CTRL via dedicated VMCS fields.
+	 */
+	if (WARN_ON_ONCE(!cpu_has_load_perf_global_ctrl()))
+		return false;
+
+	return true;
+}
+
+static void intel_pmu_write_global_ctrl(u64 global_ctrl)
+{
+	vmcs_write64(GUEST_IA32_PERF_GLOBAL_CTRL, global_ctrl);
+}
+
+
+static void intel_mediated_pmu_load(struct kvm_vcpu *vcpu)
+{
+	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
+	u64 global_status, toggle;
+
+	rdmsrq(MSR_CORE_PERF_GLOBAL_STATUS, global_status);
+	toggle = pmu->global_status ^ global_status;
+	if (global_status & toggle)
+		wrmsrq(MSR_CORE_PERF_GLOBAL_OVF_CTRL, global_status & toggle);
+	if (pmu->global_status & toggle)
+		wrmsrq(MSR_CORE_PERF_GLOBAL_STATUS_SET, pmu->global_status & toggle);
+
+	wrmsrq(MSR_CORE_PERF_FIXED_CTR_CTRL, pmu->fixed_ctr_ctrl_hw);
+}
+
+static void intel_mediated_pmu_put(struct kvm_vcpu *vcpu)
+{
+	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
+
+	/* MSR_CORE_PERF_GLOBAL_CTRL is already saved at VM-exit. */
+	rdmsrq(MSR_CORE_PERF_GLOBAL_STATUS, pmu->global_status);
+
+	/* Clear hardware MSR_CORE_PERF_GLOBAL_STATUS MSR, if non-zero. */
+	if (pmu->global_status)
+		wrmsrq(MSR_CORE_PERF_GLOBAL_OVF_CTRL, pmu->global_status);
+
+	/*
+	 * Clear hardware FIXED_CTR_CTRL MSR to avoid information leakage and
+	 * also to avoid accidentally enabling fixed counters (based on guest
+	 * state) while running in the host, e.g. when setting global ctrl.
+	 */
+	if (pmu->fixed_ctr_ctrl_hw)
+		wrmsrq(MSR_CORE_PERF_FIXED_CTR_CTRL, 0);
+}
+
 struct kvm_pmu_ops intel_pmu_ops __initdata = {
 	.rdpmc_ecx_to_pmc = intel_rdpmc_ecx_to_pmc,
 	.msr_idx_to_pmc = intel_msr_idx_to_pmc,
@@ -778,7 +832,19 @@ struct kvm_pmu_ops intel_pmu_ops __initdata = {
 	.reset = intel_pmu_reset,
 	.deliver_pmi = intel_pmu_deliver_pmi,
 	.cleanup = intel_pmu_cleanup,
+
+	.is_mediated_pmu_supported = intel_pmu_is_mediated_pmu_supported,
+	.mediated_load = intel_mediated_pmu_load,
+	.mediated_put = intel_mediated_pmu_put,
+	.write_global_ctrl = intel_pmu_write_global_ctrl,
+
 	.EVENTSEL_EVENT = ARCH_PERFMON_EVENTSEL_EVENT,
 	.MAX_NR_GP_COUNTERS = KVM_MAX_NR_INTEL_GP_COUNTERS,
 	.MIN_NR_GP_COUNTERS = 1,
+
+	.PERF_GLOBAL_CTRL = MSR_CORE_PERF_GLOBAL_CTRL,
+	.GP_EVENTSEL_BASE = MSR_P6_EVNTSEL0,
+	.GP_COUNTER_BASE = MSR_IA32_PMC0,
+	.FIXED_COUNTER_BASE = MSR_CORE_PERF_FIXED_CTR0,
+	.MSR_STRIDE = 1,
 };