KVM: arm64: Implement PV_SCHED_KICK_CPU call

euleros inclusion
category: feature
bugzilla: NA
CVE: NA

--------------------------------

Implement the service call for waking up a WFI state vCPU.
Signed-off-by: NZengruan Ye <yezengruan@huawei.com>
Reviewed-by: Nzhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/arm/include/asm/kvm_host.h

@@ -322,6 +322,11 @@ static inline int kvm_hypercall_pvsched_features(struct kvm_vcpu *vcpu)
 	return SMCCC_RET_NOT_SUPPORTED;
 }
 
+static inline int kvm_pvsched_kick_vcpu(struct kvm_vcpu *vcpu)
+{
+	return SMCCC_RET_NOT_SUPPORTED;
+}
+
 void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot);
 
 struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);

arch/arm64/include/asm/kvm_host.h

@@ -327,6 +327,7 @@ struct kvm_vcpu_arch {
 
 	/* Guest PV sched state */
 	struct {
+		bool pv_unhalted;
 		gpa_t base;
 	} pvsched;
 };
@@ -447,6 +448,7 @@ static inline bool kvm_arm_is_pvsched_enabled(struct kvm_vcpu_arch *vcpu_arch)
 
 void kvm_update_pvsched_preempted(struct kvm_vcpu *vcpu, u32 preempted);
 int kvm_hypercall_pvsched_features(struct kvm_vcpu *vcpu);
+int kvm_pvsched_kick_vcpu(struct kvm_vcpu *vcpu);
 
 void kvm_set_sei_esr(struct kvm_vcpu *vcpu, u64 syndrome);
 

arch/arm64/kvm/handle_exit.c

@@ -108,6 +108,7 @@ static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run)
 	} else {
 		trace_kvm_wfx_arm64(*vcpu_pc(vcpu), false);
 		vcpu->stat.wfi_exit_stat++;
+		vcpu->arch.pvsched.pv_unhalted = false;
 		kvm_vcpu_block(vcpu);
 		kvm_clear_request(KVM_REQ_UNHALT, vcpu);
 	}

virt/kvm/arm/arm.c

@@ -493,7 +493,9 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
 int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
 {
 	bool irq_lines = *vcpu_hcr(v) & (HCR_VI | HCR_VF);
-	return ((irq_lines || kvm_vgic_vcpu_pending_irq(v))
+	bool pv_unhalted = v->arch.pvsched.pv_unhalted;
+
+	return ((irq_lines || kvm_vgic_vcpu_pending_irq(v) || pv_unhalted)
 		&& !v->arch.power_off && !v->arch.pause);
 }
 

virt/kvm/arm/hypercalls.c

@@ -60,6 +60,9 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
 		vcpu->arch.pvsched.base = GPA_INVALID;
 		val = SMCCC_RET_SUCCESS;
 		break;
+	case ARM_SMCCC_HV_PV_SCHED_KICK_CPU:
+		val = kvm_pvsched_kick_vcpu(vcpu);
+		break;
 	default:
 		return kvm_psci_call(vcpu);
 	}

virt/kvm/arm/pvsched.c

@@ -38,6 +38,30 @@ void kvm_update_pvsched_preempted(struct kvm_vcpu *vcpu, u32 preempted)
 	pagefault_enable();
 }
 
+int kvm_pvsched_kick_vcpu(struct kvm_vcpu *vcpu)
+{
+	unsigned int vcpu_idx;
+	int val = SMCCC_RET_NOT_SUPPORTED;
+	struct kvm *kvm = vcpu->kvm;
+	struct kvm_vcpu *target = NULL;
+
+	vcpu_idx = smccc_get_arg1(vcpu);
+	target = kvm_get_vcpu(kvm, vcpu_idx);
+	if (!target)
+		goto out;
+
+	target->arch.pvsched.pv_unhalted = true;
+	kvm_make_request(KVM_REQ_IRQ_PENDING, target);
+	kvm_vcpu_kick(target);
+	if (READ_ONCE(target->ready))
+		kvm_vcpu_yield_to(target);
+
+	val = SMCCC_RET_SUCCESS;
+
+out:
+	return val;
+}
+
 int kvm_hypercall_pvsched_features(struct kvm_vcpu *vcpu)
 {
 	u32 feature = smccc_get_arg1(vcpu);
@@ -47,6 +71,7 @@ int kvm_hypercall_pvsched_features(struct kvm_vcpu *vcpu)
 	case ARM_SMCCC_HV_PV_SCHED_FEATURES:
 	case ARM_SMCCC_HV_PV_SCHED_IPA_INIT:
 	case ARM_SMCCC_HV_PV_SCHED_IPA_RELEASE:
+	case ARM_SMCCC_HV_PV_SCHED_KICK_CPU:
 		val = SMCCC_RET_SUCCESS;
 		break;
 	}