Merge branch kvm-arm64/pmu-fixes into kvmarm-master/next

Fixes for the PMUv3 emulation of PMCR_EL0:
- Don't spuriously reset the cycle counter when resetting other counters
- Force PMCR_EL0 to become effective after having restored it

* kvm-arm64/pmu-fixes:
  KVM: arm64: Restore PMU configuration on first run
  KVM: arm64: Don't zero the cycle count register when PMCR_EL0.P is set

Author: Marc Zyngier

arch/arm64/include/asm/kvm_host.h

@@ -46,6 +46,7 @@
 #define KVM_REQ_VCPU_RESET	KVM_ARCH_REQ(2)
 #define KVM_REQ_RECORD_STEAL	KVM_ARCH_REQ(3)
 #define KVM_REQ_RELOAD_GICv4	KVM_ARCH_REQ(4)
+#define KVM_REQ_RELOAD_PMU	KVM_ARCH_REQ(5)
 
 #define KVM_DIRTY_LOG_MANUAL_CAPS   (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | \
 				     KVM_DIRTY_LOG_INITIALLY_SET)

arch/arm64/kvm/arm.c

@@ -689,6 +689,10 @@ static void check_vcpu_requests(struct kvm_vcpu *vcpu)
 			vgic_v4_load(vcpu);
 			preempt_enable();
 		}
+
+		if (kvm_check_request(KVM_REQ_RELOAD_PMU, vcpu))
+			kvm_pmu_handle_pmcr(vcpu,
+					    __vcpu_sys_reg(vcpu, PMCR_EL0));
 	}
 }
 

arch/arm64/kvm/pmu-emul.c

@@ -578,6 +578,7 @@ void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val)
 		kvm_pmu_set_counter_value(vcpu, ARMV8_PMU_CYCLE_IDX, 0);
 
 	if (val & ARMV8_PMU_PMCR_P) {
+		mask &= ~BIT(ARMV8_PMU_CYCLE_IDX);
 		for_each_set_bit(i, &mask, 32)
 			kvm_pmu_set_counter_value(vcpu, i, 0);
 	}
@@ -850,6 +851,9 @@ int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu)
 		   return -EINVAL;
 	}
 
+	/* One-off reload of the PMU on first run */
+	kvm_make_request(KVM_REQ_RELOAD_PMU, vcpu);
+
 	return 0;
 }