Commit e3c1c0ca authored by Oliver Upton's avatar Oliver Upton
Browse files

KVM: arm64: Relax invariance of KVM_ARM_VCPU_POWER_OFF 

Allow the value of KVM_ARM_VCPU_POWER_OFF to differ between calls to
KVM_ARM_VCPU_INIT. Userspace can already change the state of the vCPU
through the KVM_SET_MP_STATE ioctl, so making the bit invariant seems
needlessly restrictive.

Link: https://lore.kernel.org/r/20230609190054.1542113-3-oliver.upton@linux.dev


Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
parent a7a2c72a

arch/arm64/kvm/arm.c

+12 −1
Original line number Diff line number Diff line
@@ -1236,8 +1236,19 @@ static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu, 
static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,

					 struct kvm_vcpu_init *init)

{

	bool power_off = false;

	int ret;



	/*

	 * Treat the power-off vCPU feature as ephemeral. Clear the bit to avoid

	 * reflecting it in the finalized feature set, thus limiting its scope

	 * to a single KVM_ARM_VCPU_INIT call.

	 */

	if (init->features[0] & KVM_ARM_VCPU_POWER_OFF) {

		init->features[0] &= ~KVM_ARM_VCPU_POWER_OFF;

		power_off = true;

	}



	ret = kvm_vcpu_set_target(vcpu, init);

	if (ret)

		return ret;
@@ -1266,7 +1277,7 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu, 
	 */

	spin_lock(&vcpu->arch.mp_state_lock);



	if (test_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features))

	if (power_off)

		__kvm_arm_vcpu_power_off(vcpu);

	else

		WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_RUNNABLE);