Merge branch 'kvm-arm64/pmu-undef' into kvmarm-master/next

Signed-off-by: Marc Zyngier <maz@kernel.org>

arch/arm64/include/asm/kvm_host.h

@@ -733,4 +733,7 @@ bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu);
 #define kvm_arm_vcpu_sve_finalized(vcpu) \
 	((vcpu)->arch.flags & KVM_ARM64_VCPU_SVE_FINALIZED)
 
+#define kvm_vcpu_has_pmu(vcpu)					\
+	(test_bit(KVM_ARM_VCPU_PMU_V3, (vcpu)->arch.features))
+
 #endif /* __ARM64_KVM_HOST_H__ */

arch/arm64/kvm/pmu-emul.c

@@ -384,7 +384,7 @@ static void kvm_pmu_update_state(struct kvm_vcpu *vcpu)
 	struct kvm_pmu *pmu = &vcpu->arch.pmu;
 	bool overflow;
 
-	if (!kvm_arm_pmu_v3_ready(vcpu))
+	if (!kvm_vcpu_has_pmu(vcpu))
 		return;
 
 	overflow = !!kvm_pmu_overflow_status(vcpu);
@@ -825,19 +825,19 @@ bool kvm_arm_support_pmu_v3(void)
 
 int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu)
 {
-	if (!vcpu->arch.pmu.created)
+	if (!kvm_vcpu_has_pmu(vcpu))
 		return 0;
 
+	if (!vcpu->arch.pmu.created)
+		return -EINVAL;
+
 	/*
 	 * A valid interrupt configuration for the PMU is either to have a
 	 * properly configured interrupt number and using an in-kernel
 	 * irqchip, or to not have an in-kernel GIC and not set an IRQ.
 	 */
 	if (irqchip_in_kernel(vcpu->kvm)) {
 		int irq = vcpu->arch.pmu.irq_num;
-		if (!kvm_arm_pmu_irq_initialized(vcpu))
-			return -EINVAL;
-
 		/*
 		 * If we are using an in-kernel vgic, at this point we know
 		 * the vgic will be initialized, so we can check the PMU irq
@@ -851,7 +851,6 @@ int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu)
 	}
 
 	kvm_pmu_vcpu_reset(vcpu);
-	vcpu->arch.pmu.ready = true;
 
 	return 0;
 }
@@ -913,8 +912,7 @@ static bool pmu_irq_is_valid(struct kvm *kvm, int irq)
 
 int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 {
-	if (!kvm_arm_support_pmu_v3() ||
-	    !test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features))
+	if (!kvm_vcpu_has_pmu(vcpu))
 		return -ENODEV;
 
 	if (vcpu->arch.pmu.created)
@@ -1015,7 +1013,7 @@ int kvm_arm_pmu_v3_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 		if (!irqchip_in_kernel(vcpu->kvm))
 			return -EINVAL;
 
-		if (!test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features))
+		if (!kvm_vcpu_has_pmu(vcpu))
 			return -ENODEV;
 
 		if (!kvm_arm_pmu_irq_initialized(vcpu))
@@ -1035,8 +1033,7 @@ int kvm_arm_pmu_v3_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 	case KVM_ARM_VCPU_PMU_V3_IRQ:
 	case KVM_ARM_VCPU_PMU_V3_INIT:
 	case KVM_ARM_VCPU_PMU_V3_FILTER:
-		if (kvm_arm_support_pmu_v3() &&
-		    test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features))
+		if (kvm_vcpu_has_pmu(vcpu))
 			return 0;
 	}
 

arch/arm64/kvm/reset.c

@@ -285,6 +285,10 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
 			pstate = VCPU_RESET_PSTATE_EL1;
 		}
 
+		if (kvm_vcpu_has_pmu(vcpu) && !kvm_arm_support_pmu_v3()) {
+			ret = -EINVAL;
+			goto out;
+		}
 		break;
 	}
 

arch/arm64/kvm/sys_regs.c

@@ -609,8 +609,9 @@ static void reset_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
 static bool check_pmu_access_disabled(struct kvm_vcpu *vcpu, u64 flags)
 {
 	u64 reg = __vcpu_sys_reg(vcpu, PMUSERENR_EL0);
-	bool enabled = (reg & flags) || vcpu_mode_priv(vcpu);
+	bool enabled = kvm_vcpu_has_pmu(vcpu);
 
+	enabled &= (reg & flags) || vcpu_mode_priv(vcpu);
 	if (!enabled)
 		kvm_inject_undefined(vcpu);
 
@@ -642,9 +643,6 @@ static bool access_pmcr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 {
 	u64 val;
 
-	if (!kvm_arm_pmu_v3_ready(vcpu))
-		return trap_raz_wi(vcpu, p, r);
-
 	if (pmu_access_el0_disabled(vcpu))
 		return false;
 
@@ -671,9 +669,6 @@ static bool access_pmcr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 static bool access_pmselr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 			  const struct sys_reg_desc *r)
 {
-	if (!kvm_arm_pmu_v3_ready(vcpu))
-		return trap_raz_wi(vcpu, p, r);
-
 	if (pmu_access_event_counter_el0_disabled(vcpu))
 		return false;
 
@@ -692,9 +687,6 @@ static bool access_pmceid(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 {
 	u64 pmceid;
 
-	if (!kvm_arm_pmu_v3_ready(vcpu))
-		return trap_raz_wi(vcpu, p, r);
-
 	BUG_ON(p->is_write);
 
 	if (pmu_access_el0_disabled(vcpu))
@@ -725,10 +717,7 @@ static bool access_pmu_evcntr(struct kvm_vcpu *vcpu,
 			      struct sys_reg_params *p,
 			      const struct sys_reg_desc *r)
 {
-	u64 idx;
-
-	if (!kvm_arm_pmu_v3_ready(vcpu))
-		return trap_raz_wi(vcpu, p, r);
+	u64 idx = ~0UL;
 
 	if (r->CRn == 9 && r->CRm == 13) {
 		if (r->Op2 == 2) {
@@ -744,8 +733,6 @@ static bool access_pmu_evcntr(struct kvm_vcpu *vcpu,
 				return false;
 
 			idx = ARMV8_PMU_CYCLE_IDX;
-		} else {
-			return false;
 		}
 	} else if (r->CRn == 0 && r->CRm == 9) {
 		/* PMCCNTR */
@@ -759,10 +746,11 @@ static bool access_pmu_evcntr(struct kvm_vcpu *vcpu,
 			return false;
 
 		idx = ((r->CRm & 3) << 3) | (r->Op2 & 7);
-	} else {
-		return false;
 	}
 
+	/* Catch any decoding mistake */
+	WARN_ON(idx == ~0UL);
+
 	if (!pmu_counter_idx_valid(vcpu, idx))
 		return false;
 
@@ -783,9 +771,6 @@ static bool access_pmu_evtyper(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 {
 	u64 idx, reg;
 
-	if (!kvm_arm_pmu_v3_ready(vcpu))
-		return trap_raz_wi(vcpu, p, r);
-
 	if (pmu_access_el0_disabled(vcpu))
 		return false;
 
@@ -823,9 +808,6 @@ static bool access_pmcnten(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 {
 	u64 val, mask;
 
-	if (!kvm_arm_pmu_v3_ready(vcpu))
-		return trap_raz_wi(vcpu, p, r);
-
 	if (pmu_access_el0_disabled(vcpu))
 		return false;
 
@@ -854,13 +836,8 @@ static bool access_pminten(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 {
 	u64 mask = kvm_pmu_valid_counter_mask(vcpu);
 
-	if (!kvm_arm_pmu_v3_ready(vcpu))
-		return trap_raz_wi(vcpu, p, r);
-
-	if (!vcpu_mode_priv(vcpu)) {
-		kvm_inject_undefined(vcpu);
+	if (check_pmu_access_disabled(vcpu, 0))
 		return false;
-	}
 
 	if (p->is_write) {
 		u64 val = p->regval & mask;
@@ -883,9 +860,6 @@ static bool access_pmovs(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 {
 	u64 mask = kvm_pmu_valid_counter_mask(vcpu);
 
-	if (!kvm_arm_pmu_v3_ready(vcpu))
-		return trap_raz_wi(vcpu, p, r);
-
 	if (pmu_access_el0_disabled(vcpu))
 		return false;
 
@@ -908,9 +882,6 @@ static bool access_pmswinc(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 {
 	u64 mask;
 
-	if (!kvm_arm_pmu_v3_ready(vcpu))
-		return trap_raz_wi(vcpu, p, r);
-
 	if (!p->is_write)
 		return read_from_write_only(vcpu, p, r);
 
@@ -925,8 +896,10 @@ static bool access_pmswinc(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 			     const struct sys_reg_desc *r)
 {
-	if (!kvm_arm_pmu_v3_ready(vcpu))
-		return trap_raz_wi(vcpu, p, r);
+	if (!kvm_vcpu_has_pmu(vcpu)) {
+		kvm_inject_undefined(vcpu);
+		return false;
+	}
 
 	if (p->is_write) {
 		if (!vcpu_mode_priv(vcpu)) {
@@ -1061,10 +1034,15 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
 			 (0xfUL << ID_AA64ISAR1_GPA_SHIFT) |
 			 (0xfUL << ID_AA64ISAR1_GPI_SHIFT));
 	} else if (id == SYS_ID_AA64DFR0_EL1) {
+		u64 cap = 0;
+
 		/* Limit guests to PMUv3 for ARMv8.1 */
+		if (kvm_vcpu_has_pmu(vcpu))
+			cap = ID_AA64DFR0_PMUVER_8_1;
+
 		val = cpuid_feature_cap_perfmon_field(val,
 						ID_AA64DFR0_PMUVER_SHIFT,
-						ID_AA64DFR0_PMUVER_8_1);
+						cap);
 	} else if (id == SYS_ID_DFR0_EL1) {
 		/* Limit guests to PMUv3 for ARMv8.1 */
 		val = cpuid_feature_cap_perfmon_field(val,

include/kvm/arm_pmu.h

@@ -24,13 +24,11 @@ struct kvm_pmu {
 	int irq_num;
 	struct kvm_pmc pmc[ARMV8_PMU_MAX_COUNTERS];
 	DECLARE_BITMAP(chained, ARMV8_PMU_MAX_COUNTER_PAIRS);
-	bool ready;
 	bool created;
 	bool irq_level;
 	struct irq_work overflow_work;
 };
 
-#define kvm_arm_pmu_v3_ready(v)		((v)->arch.pmu.ready)
 #define kvm_arm_pmu_irq_initialized(v)	((v)->arch.pmu.irq_num >= VGIC_NR_SGIS)
 u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx);
 void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val);
@@ -61,7 +59,6 @@ int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu);
 struct kvm_pmu {
 };
 
-#define kvm_arm_pmu_v3_ready(v)		(false)
 #define kvm_arm_pmu_irq_initialized(v)	(false)
 static inline u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu,
 					    u64 select_idx)