Commit 923961a7 authored by Will Deacon's avatar Will Deacon Committed by Marc Zyngier
Browse files

KVM: arm64: Advertise KVM UID to guests via SMCCC 



We can advertise ourselves to guests as KVM and provide a basic features
bitmap for discoverability of future hypervisor services.

Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarJianyong Wu <jianyong.wu@arm.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201209060932.212364-3-jianyong.wu@arm.com
parent 6e085e0a

arch/arm64/kvm/hypercalls.c

+18 −9
Original line number Diff line number Diff line
@@ -12,13 +12,13 @@ 
int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)

{

	u32 func_id = smccc_get_function(vcpu);

	long val = SMCCC_RET_NOT_SUPPORTED;

	u64 val[4] = {SMCCC_RET_NOT_SUPPORTED};

	u32 feature;

	gpa_t gpa;



	switch (func_id) {

	case ARM_SMCCC_VERSION_FUNC_ID:

		val = ARM_SMCCC_VERSION_1_1;

		val[0] = ARM_SMCCC_VERSION_1_1;

		break;

	case ARM_SMCCC_ARCH_FEATURES_FUNC_ID:

		feature = smccc_get_arg1(vcpu);
@@ -28,10 +28,10 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) 
			case SPECTRE_VULNERABLE:

				break;

			case SPECTRE_MITIGATED:

				val = SMCCC_RET_SUCCESS;

				val[0] = SMCCC_RET_SUCCESS;

				break;

			case SPECTRE_UNAFFECTED:

				val = SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED;

				val[0] = SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED;

				break;

			}

			break;
@@ -54,22 +54,31 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) 
					break;

				fallthrough;

			case SPECTRE_UNAFFECTED:

				val = SMCCC_RET_NOT_REQUIRED;

				val[0] = SMCCC_RET_NOT_REQUIRED;

				break;

			}

			break;

		case ARM_SMCCC_HV_PV_TIME_FEATURES:

			val = SMCCC_RET_SUCCESS;

			val[0] = SMCCC_RET_SUCCESS;

			break;

		}

		break;

	case ARM_SMCCC_HV_PV_TIME_FEATURES:

		val = kvm_hypercall_pv_features(vcpu);

		val[0] = kvm_hypercall_pv_features(vcpu);

		break;

	case ARM_SMCCC_HV_PV_TIME_ST:

		gpa = kvm_init_stolen_time(vcpu);

		if (gpa != GPA_INVALID)

			val = gpa;

			val[0] = gpa;

		break;

	case ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID:

		val[0] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_0;

		val[1] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_1;

		val[2] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2;

		val[3] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_3;

		break;

	case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:

		val[0] = BIT(ARM_SMCCC_KVM_FUNC_FEATURES);

		break;

	case ARM_SMCCC_TRNG_VERSION:

	case ARM_SMCCC_TRNG_FEATURES:
@@ -81,6 +90,6 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) 
		return kvm_psci_call(vcpu);

	}



	smccc_set_retval(vcpu, val, 0, 0, 0);

	smccc_set_retval(vcpu, val[0], val[1], val[2], val[3]);

	return 1;

}