diff mbox series

[v2,15/20] aarch64: psci: Implement CPU_OFF

Message ID 20230620163353.2688567-16-oliver.upton@linux.dev (mailing list archive)
State New, archived
Headers show
Series arm64: Handle PSCI calls in userspace | expand

Commit Message

Oliver Upton June 20, 2023, 4:33 p.m. UTC 
Add support for PSCI CPU_OFF, relying on KVM emulation of a 'powered
off' vCPU by setting the MP state to KVM_MP_STATE_STOPPED.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
 arm/aarch64/psci.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
diff mbox series

Patch

diff --git a/arm/aarch64/psci.c b/arm/aarch64/psci.c
index abfdc76..72429b3 100644
--- a/arm/aarch64/psci.c
+++ b/arm/aarch64/psci.c
@@ -17,6 +17,7 @@  static void psci_features(struct kvm_cpu *vcpu, struct arm_smccc_res *res)
 	switch (arg) {
 	case PSCI_0_2_FN_CPU_SUSPEND:
 	case PSCI_0_2_FN64_CPU_SUSPEND:
+	case PSCI_0_2_FN_CPU_OFF:
 	case ARM_SMCCC_VERSION_FUNC_ID:
 		res->a0 = PSCI_RET_SUCCESS;
 		break;
@@ -36,6 +37,16 @@  static void cpu_suspend(struct kvm_cpu *vcpu, struct arm_smccc_res *res)
 	res->a0 = PSCI_RET_SUCCESS;
 }
 
+static void cpu_off(struct kvm_cpu *vcpu, struct arm_smccc_res *res)
+{
+	struct kvm_mp_state mp_state = {
+		.mp_state	= KVM_MP_STATE_STOPPED,
+	};
+
+	if (ioctl(vcpu->vcpu_fd, KVM_SET_MP_STATE, &mp_state))
+		die_perror("KVM_SET_MP_STATE failed");
+}
+
 void handle_psci(struct kvm_cpu *vcpu, struct arm_smccc_res *res)
 {
 	switch (vcpu->kvm_run->hypercall.nr) {
@@ -49,6 +60,9 @@  void handle_psci(struct kvm_cpu *vcpu, struct arm_smccc_res *res)
 	case PSCI_0_2_FN64_CPU_SUSPEND:
 		cpu_suspend(vcpu, res);
 		break;
+	case PSCI_0_2_FN_CPU_OFF:
+		cpu_off(vcpu, res);
+		break;
 	default:
 		res->a0 = PSCI_RET_NOT_SUPPORTED;
 	}