arch/arm64/kvm/hypercalls.c

Source file repositories/reference/linux-study-clean/arch/arm64/kvm/hypercalls.c

File Facts

System
Linux kernel
Corpus path
arch/arm64/kvm/hypercalls.c
Extension
.c
Size
18051 bytes
Lines
680
Domain
Architecture Layer
Bucket
arch/arm64
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

switch (feature) {
		case ARM_SMCCC_ARCH_WORKAROUND_1:
			switch (arm64_get_spectre_v2_state()) {
			case SPECTRE_VULNERABLE:
				break;
			case SPECTRE_MITIGATED:
				val[0] = SMCCC_RET_SUCCESS;
				break;
			case SPECTRE_UNAFFECTED:
				val[0] = SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED;
				break;
			}
			break;
		case ARM_SMCCC_ARCH_WORKAROUND_2:
			switch (arm64_get_spectre_v4_state()) {
			case SPECTRE_VULNERABLE:
				break;
			case SPECTRE_MITIGATED:
				/*
				 * SSBS everywhere: Indicate no firmware
				 * support, as the SSBS support will be
				 * indicated to the guest and the default is
				 * safe.
				 *
				 * Otherwise, expose a permanent mitigation
				 * to the guest, and hide SSBS so that the
				 * guest stays protected.
				 */
				if (kvm_has_feat(vcpu->kvm, ID_AA64PFR1_EL1, SSBS, IMP))
					break;
				fallthrough;
			case SPECTRE_UNAFFECTED:
				val[0] = SMCCC_RET_NOT_REQUIRED;
				break;
			}
			break;
		case ARM_SMCCC_ARCH_WORKAROUND_3:
			switch (arm64_get_spectre_bhb_state()) {
			case SPECTRE_VULNERABLE:
				break;
			case SPECTRE_MITIGATED:
				val[0] = SMCCC_RET_SUCCESS;
				break;
			case SPECTRE_UNAFFECTED:
				val[0] = SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED;
				break;
			}
			break;
		case ARM_SMCCC_HV_PV_TIME_FEATURES:
			if (test_bit(KVM_REG_ARM_STD_HYP_BIT_PV_TIME,
				     &smccc_feat->std_hyp_bmap))
				val[0] = SMCCC_RET_SUCCESS;
			break;
		}
		break;
	case ARM_SMCCC_HV_PV_TIME_FEATURES:
		val[0] = kvm_hypercall_pv_features(vcpu);
		break;
	case ARM_SMCCC_HV_PV_TIME_ST:
		gpa = kvm_init_stolen_time(vcpu);
		if (gpa != INVALID_GPA)
			val[0] = gpa;
		break;
	case ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID:
		uuid = ARM_SMCCC_VENDOR_HYP_UID_KVM;
		val[0] = smccc_uuid_to_reg(&uuid, 0);
		val[1] = smccc_uuid_to_reg(&uuid, 1);
		val[2] = smccc_uuid_to_reg(&uuid, 2);
		val[3] = smccc_uuid_to_reg(&uuid, 3);
		break;
	case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:
		val[0] = smccc_feat->vendor_hyp_bmap;
		/* Function numbers 2-63 are reserved for pKVM for now */
		val[2] = smccc_feat->vendor_hyp_bmap_2;
		break;
	case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
		kvm_ptp_get_time(vcpu, val);
		break;
	case ARM_SMCCC_TRNG_VERSION:
	case ARM_SMCCC_TRNG_FEATURES:
	case ARM_SMCCC_TRNG_GET_UUID:
	case ARM_SMCCC_TRNG_RND32:
	case ARM_SMCCC_TRNG_RND64:
		return kvm_trng_call(vcpu);
	default:
		return kvm_psci_call(vcpu);
	}

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

Annotation

Implementation Notes