arm64: KVM: Add a new feature bit for PMUv3

To support guest PMUv3, use one bit of the VCPU INIT feature array.
Initialize the PMU when initialzing the vcpu with that bit and PMU
overflow interrupt set.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 07e4cdf024073033e2a52213bcbed4d562111a33..9684f8dc6bb2414934427adee6f7169ed0bf3239 100644 (file)
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2577,6 +2577,8 @@ Possible features:
          Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only).
        - KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 for the CPU.
          Depends on KVM_CAP_ARM_PSCI_0_2.
+       - KVM_ARM_VCPU_PMU_V3: Emulate PMUv3 for the CPU.
+         Depends on KVM_CAP_ARM_PMU_V3.
 
 
 4.83 KVM_ARM_PREFERRED_TARGET

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index a819c6debce40fead71b3f9507a1b3c1484be6a4..b02ef0828f220dca7e09984acb2218f4130f0caf 100644 (file)
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -42,7 +42,7 @@
 
 #define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS
 
-#define KVM_VCPU_MAX_FEATURES 3
+#define KVM_VCPU_MAX_FEATURES 4
 
 int __attribute_const__ kvm_target_cpu(void);
 int kvm_reset_vcpu(struct kvm_vcpu *vcpu);

diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 2d4ca4bb0dd34a18ed6bfde2d5fa4e4319402903..6aedbe3144320cd48301545bbf91745635195026 100644 (file)
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -94,6 +94,7 @@ struct kvm_regs {
 #define KVM_ARM_VCPU_POWER_OFF         0 /* CPU is started in OFF state */
 #define KVM_ARM_VCPU_EL1_32BIT         1 /* CPU running a 32bit VM */
 #define KVM_ARM_VCPU_PSCI_0_2          2 /* CPU uses PSCI v0.2 */
+#define KVM_ARM_VCPU_PMU_V3            3 /* Support guest PMUv3 */
 
 struct kvm_vcpu_init {
        __u32 target;

diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index dfbce781d284d6a92ef71f88cd3c54305c1e3bbf..cf4f28a7a5144ccaa79e92194801797c943aeaf1 100644 (file)
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -77,6 +77,9 @@ int kvm_arch_dev_ioctl_check_extension(long ext)
        case KVM_CAP_GUEST_DEBUG_HW_WPS:
                r = get_num_wrps();
                break;
+       case KVM_CAP_ARM_PMU_V3:
+               r = kvm_arm_support_pmu_v3();
+               break;
        case KVM_CAP_SET_GUEST_DEBUG:
                r = 1;
                break;

diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index 9f87d717ef84234ea22f3e725a4c5b4b161d725d..ee62497d46f7559f275e0ff3a8811c18ce026d9e 100644 (file)
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -53,6 +53,7 @@ void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val);
 void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val);
 void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,
                                    u64 select_idx);
+bool kvm_arm_support_pmu_v3(void);
 #else
 struct kvm_pmu {
 };
@@ -80,6 +81,7 @@ static inline void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val) {}
 static inline void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) {}
 static inline void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu,
                                                  u64 data, u64 select_idx) {}
+static inline bool kvm_arm_support_pmu_v3(void) { return false; }
 #endif
 
 #endif

diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 9da905157ceeebcb5afbd9e73b8ac56195954929..dc16d3084d4a4f706b7d3dd5a95c4d29a34e6a51 100644 (file)
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -850,6 +850,7 @@ struct kvm_ppc_smmu_info {
 #define KVM_CAP_IOEVENTFD_ANY_LENGTH 122
 #define KVM_CAP_HYPERV_SYNIC 123
 #define KVM_CAP_S390_RI 124
+#define KVM_CAP_ARM_PMU_V3 125
 
 #ifdef KVM_CAP_IRQ_ROUTING
 

diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index 9b83857da195e11107b3939f1e3d0b4c0012fb9e..6e28f4f86cc6775e836f28f5a9d7f19f523ea33a 100644 (file)
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -405,3 +405,13 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,
 
        pmc->perf_event = event;
 }
+
+bool kvm_arm_support_pmu_v3(void)
+{
+       /*
+        * Check if HW_PERF_EVENTS are supported by checking the number of
+        * hardware performance counters. This could ensure the presence of
+        * a physical PMU and CONFIG_PERF_EVENT is selected.
+        */
+       return (perf_num_counters() > 0);
+}