static int vmx_get_msr()

in kvm/vmx/vmx.c [1778:1926]

• 138 lines of code
• 54 McCabe index (conditional complexity)

static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
	struct vcpu_vmx *vmx = to_vmx(vcpu);
	struct vmx_uret_msr *msr;
	u32 index;

	switch (msr_info->index) {
#ifdef CONFIG_X86_64
	case MSR_FS_BASE:
		msr_info->data = vmcs_readl(GUEST_FS_BASE);
		break;
	case MSR_GS_BASE:
		msr_info->data = vmcs_readl(GUEST_GS_BASE);
		break;
	case MSR_KERNEL_GS_BASE:
		msr_info->data = vmx_read_guest_kernel_gs_base(vmx);
		break;
#endif
	case MSR_EFER:
		return kvm_get_msr_common(vcpu, msr_info);
	case MSR_IA32_TSX_CTRL:
		if (!msr_info->host_initiated &&
		    !(vcpu->arch.arch_capabilities & ARCH_CAP_TSX_CTRL_MSR))
			return 1;
		goto find_uret_msr;
	case MSR_IA32_UMWAIT_CONTROL:
		if (!msr_info->host_initiated && !vmx_has_waitpkg(vmx))
			return 1;

		msr_info->data = vmx->msr_ia32_umwait_control;
		break;
	case MSR_IA32_SPEC_CTRL:
		if (!msr_info->host_initiated &&
		    !guest_has_spec_ctrl_msr(vcpu))
			return 1;

		msr_info->data = to_vmx(vcpu)->spec_ctrl;
		break;
	case MSR_IA32_SYSENTER_CS:
		msr_info->data = vmcs_read32(GUEST_SYSENTER_CS);
		break;
	case MSR_IA32_SYSENTER_EIP:
		msr_info->data = vmcs_readl(GUEST_SYSENTER_EIP);
		break;
	case MSR_IA32_SYSENTER_ESP:
		msr_info->data = vmcs_readl(GUEST_SYSENTER_ESP);
		break;
	case MSR_IA32_BNDCFGS:
		if (!kvm_mpx_supported() ||
		    (!msr_info->host_initiated &&
		     !guest_cpuid_has(vcpu, X86_FEATURE_MPX)))
			return 1;
		msr_info->data = vmcs_read64(GUEST_BNDCFGS);
		break;
	case MSR_IA32_MCG_EXT_CTL:
		if (!msr_info->host_initiated &&
		    !(vmx->msr_ia32_feature_control &
		      FEAT_CTL_LMCE_ENABLED))
			return 1;
		msr_info->data = vcpu->arch.mcg_ext_ctl;
		break;
	case MSR_IA32_FEAT_CTL:
		msr_info->data = vmx->msr_ia32_feature_control;
		break;
	case MSR_IA32_SGXLEPUBKEYHASH0 ... MSR_IA32_SGXLEPUBKEYHASH3:
		if (!msr_info->host_initiated &&
		    !guest_cpuid_has(vcpu, X86_FEATURE_SGX_LC))
			return 1;
		msr_info->data = to_vmx(vcpu)->msr_ia32_sgxlepubkeyhash
			[msr_info->index - MSR_IA32_SGXLEPUBKEYHASH0];
		break;
	case MSR_IA32_VMX_BASIC ... MSR_IA32_VMX_VMFUNC:
		if (!nested_vmx_allowed(vcpu))
			return 1;
		if (vmx_get_vmx_msr(&vmx->nested.msrs, msr_info->index,
				    &msr_info->data))
			return 1;
		/*
		 * Enlightened VMCS v1 doesn't have certain VMCS fields but
		 * instead of just ignoring the features, different Hyper-V
		 * versions are either trying to use them and fail or do some
		 * sanity checking and refuse to boot. Filter all unsupported
		 * features out.
		 */
		if (!msr_info->host_initiated &&
		    vmx->nested.enlightened_vmcs_enabled)
			nested_evmcs_filter_control_msr(msr_info->index,
							&msr_info->data);
		break;
	case MSR_IA32_RTIT_CTL:
		if (!vmx_pt_mode_is_host_guest())
			return 1;
		msr_info->data = vmx->pt_desc.guest.ctl;
		break;
	case MSR_IA32_RTIT_STATUS:
		if (!vmx_pt_mode_is_host_guest())
			return 1;
		msr_info->data = vmx->pt_desc.guest.status;
		break;
	case MSR_IA32_RTIT_CR3_MATCH:
		if (!vmx_pt_mode_is_host_guest() ||
			!intel_pt_validate_cap(vmx->pt_desc.caps,
						PT_CAP_cr3_filtering))
			return 1;
		msr_info->data = vmx->pt_desc.guest.cr3_match;
		break;
	case MSR_IA32_RTIT_OUTPUT_BASE:
		if (!vmx_pt_mode_is_host_guest() ||
			(!intel_pt_validate_cap(vmx->pt_desc.caps,
					PT_CAP_topa_output) &&
			 !intel_pt_validate_cap(vmx->pt_desc.caps,
					PT_CAP_single_range_output)))
			return 1;
		msr_info->data = vmx->pt_desc.guest.output_base;
		break;
	case MSR_IA32_RTIT_OUTPUT_MASK:
		if (!vmx_pt_mode_is_host_guest() ||
			(!intel_pt_validate_cap(vmx->pt_desc.caps,
					PT_CAP_topa_output) &&
			 !intel_pt_validate_cap(vmx->pt_desc.caps,
					PT_CAP_single_range_output)))
			return 1;
		msr_info->data = vmx->pt_desc.guest.output_mask;
		break;
	case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B:
		index = msr_info->index - MSR_IA32_RTIT_ADDR0_A;
		if (!vmx_pt_mode_is_host_guest() ||
		    (index >= 2 * vmx->pt_desc.num_address_ranges))
			return 1;
		if (index % 2)
			msr_info->data = vmx->pt_desc.guest.addr_b[index / 2];
		else
			msr_info->data = vmx->pt_desc.guest.addr_a[index / 2];
		break;
	case MSR_IA32_DEBUGCTLMSR:
		msr_info->data = vmcs_read64(GUEST_IA32_DEBUGCTL);
		break;
	default:
	find_uret_msr:
		msr = vmx_find_uret_msr(vmx, msr_info->index);
		if (msr) {
			msr_info->data = msr->data;
			break;
		}
		return kvm_get_msr_common(vcpu, msr_info);
	}

	return 0;
}