Commit 8cab6507 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Paolo Bonzini
Browse files

x86/kvm/nVMX: nested state migration for Enlightened VMCS 



Add support for get/set of nested state when Enlightened VMCS is in use.
A new KVM_STATE_NESTED_EVMCS flag to indicate eVMCS on the vCPU was enabled
is added.

Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 1e7ecd1b

arch/x86/include/uapi/asm/kvm.h

+1 −0
Original line number Diff line number Diff line
@@ -381,6 +381,7 @@ struct kvm_sync_regs { 


#define KVM_STATE_NESTED_GUEST_MODE	0x00000001

#define KVM_STATE_NESTED_RUN_PENDING	0x00000002

#define KVM_STATE_NESTED_EVMCS		0x00000004



#define KVM_STATE_NESTED_SMM_GUEST_MODE	0x00000001

#define KVM_STATE_NESTED_SMM_VMXON	0x00000002

arch/x86/kvm/vmx.c

+60 −18
Original line number Diff line number Diff line
@@ -1618,6 +1618,7 @@ static int nested_enable_evmcs(struct kvm_vcpu *vcpu, 
	 * maximum supported version. KVM supports versions from 1 to

	 * KVM_EVMCS_VERSION.

	 */

	if (vmcs_version)

		*vmcs_version = (KVM_EVMCS_VERSION << 8) | 1;



	vmx->nested.msrs.pinbased_ctls_high &= ~EVMCS1_UNSUPPORTED_PINCTRL;
@@ -9338,7 +9339,8 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu) 
 * This is an equivalent of the nested hypervisor executing the vmptrld

 * instruction.

 */

static int nested_vmx_handle_enlightened_vmptrld(struct kvm_vcpu *vcpu)

static int nested_vmx_handle_enlightened_vmptrld(struct kvm_vcpu *vcpu,

						 bool from_launch)

{

	struct vcpu_vmx *vmx = to_vmx(vcpu);

	struct hv_vp_assist_page assist_page;
@@ -9389,6 +9391,7 @@ static int nested_vmx_handle_enlightened_vmptrld(struct kvm_vcpu *vcpu) 
		 * present in struct hv_enlightened_vmcs, ...). Make sure there

		 * are no leftovers.

		 */

		if (from_launch)

			memset(vmx->nested.cached_vmcs12, 0,

			       sizeof(*vmx->nested.cached_vmcs12));
@@ -11147,6 +11150,15 @@ static void __noclone vmx_vcpu_run(struct kvm_vcpu *vcpu) 
	}



	if (vmx->nested.need_vmcs12_sync) {

		/*

		 * hv_evmcs may end up being not mapped after migration (when

		 * L2 was running), map it here to make sure vmcs12 changes are

		 * properly reflected.

		 */

		if (vmx->nested.enlightened_vmcs_enabled &&

		    !vmx->nested.hv_evmcs)

			nested_vmx_handle_enlightened_vmptrld(vcpu, false);



		if (vmx->nested.hv_evmcs) {

			copy_vmcs12_to_enlightened(vmx);

			/* All fields are clean */
@@ -13424,7 +13436,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) 
	if (!nested_vmx_check_permission(vcpu))

		return 1;



	if (!nested_vmx_handle_enlightened_vmptrld(vcpu))

	if (!nested_vmx_handle_enlightened_vmptrld(vcpu, true))

		return 1;



	if (!vmx->nested.hv_evmcs && vmx->nested.current_vmptr == -1ull)
@@ -14711,6 +14723,20 @@ static int enable_smi_window(struct kvm_vcpu *vcpu) 
	return 0;

}



static inline int vmx_has_valid_vmcs12(struct kvm_vcpu *vcpu)

{

	struct vcpu_vmx *vmx = to_vmx(vcpu);



	/*

	 * In case we do two consecutive get/set_nested_state()s while L2 was

	 * running hv_evmcs may end up not being mapped (we map it from

	 * nested_vmx_run()/vmx_vcpu_run()). Check is_guest_mode() as we always

	 * have vmcs12 if it is true.

	 */

	return is_guest_mode(vcpu) || vmx->nested.current_vmptr != -1ull ||

		vmx->nested.hv_evmcs;

}



static int vmx_get_nested_state(struct kvm_vcpu *vcpu,

				struct kvm_nested_state __user *user_kvm_nested_state,

				u32 user_data_size)
@@ -14731,16 +14757,15 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, 
	vmx = to_vmx(vcpu);

	vmcs12 = get_vmcs12(vcpu);



	/* FIXME: Enlightened VMCS is currently unsupported */

	if (vmx->nested.hv_evmcs)

		return -ENOTSUPP;

	if (nested_vmx_allowed(vcpu) && vmx->nested.enlightened_vmcs_enabled)

		kvm_state.flags |= KVM_STATE_NESTED_EVMCS;



	if (nested_vmx_allowed(vcpu) &&

	    (vmx->nested.vmxon || vmx->nested.smm.vmxon)) {

		kvm_state.vmx.vmxon_pa = vmx->nested.vmxon_ptr;

		kvm_state.vmx.vmcs_pa = vmx->nested.current_vmptr;



		if (vmx->nested.current_vmptr != -1ull) {

		if (vmx_has_valid_vmcs12(vcpu)) {

			kvm_state.size += VMCS12_SIZE;



			if (is_guest_mode(vcpu) &&
@@ -14769,20 +14794,24 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu, 
	if (copy_to_user(user_kvm_nested_state, &kvm_state, sizeof(kvm_state)))

		return -EFAULT;



	if (vmx->nested.current_vmptr == -1ull)

	if (!vmx_has_valid_vmcs12(vcpu))

		goto out;



	/*

	 * When running L2, the authoritative vmcs12 state is in the

	 * vmcs02. When running L1, the authoritative vmcs12 state is

	 * in the shadow vmcs linked to vmcs01, unless

	 * in the shadow or enlightened vmcs linked to vmcs01, unless

	 * need_vmcs12_sync is set, in which case, the authoritative

	 * vmcs12 state is in the vmcs12 already.

	 */

	if (is_guest_mode(vcpu))

	if (is_guest_mode(vcpu)) {

		sync_vmcs12(vcpu, vmcs12);

	else if (enable_shadow_vmcs && !vmx->nested.need_vmcs12_sync)

	} else if (!vmx->nested.need_vmcs12_sync) {

		if (vmx->nested.hv_evmcs)

			copy_enlightened_to_vmcs12(vmx);

		else if (enable_shadow_vmcs)

			copy_shadow_to_vmcs12(vmx);

	}



	if (copy_to_user(user_kvm_nested_state->data, vmcs12, sizeof(*vmcs12)))

		return -EFAULT;
@@ -14810,6 +14839,9 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, 
	if (kvm_state->format != 0)

		return -EINVAL;



	if (kvm_state->flags & KVM_STATE_NESTED_EVMCS)

		nested_enable_evmcs(vcpu, NULL);



	if (!nested_vmx_allowed(vcpu))

		return kvm_state->vmx.vmxon_pa == -1ull ? 0 : -EINVAL;
@@ -14860,11 +14892,21 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu, 
	if (kvm_state->size < sizeof(kvm_state) + sizeof(*vmcs12))

		return 0;



	if (kvm_state->vmx.vmcs_pa != -1ull) {

		if (kvm_state->vmx.vmcs_pa == kvm_state->vmx.vmxon_pa ||

		    !page_address_valid(vcpu, kvm_state->vmx.vmcs_pa))

			return -EINVAL;



		set_current_vmptr(vmx, kvm_state->vmx.vmcs_pa);

	} else if (kvm_state->flags & KVM_STATE_NESTED_EVMCS) {

		/*

		 * Sync eVMCS upon entry as we may not have

		 * HV_X64_MSR_VP_ASSIST_PAGE set up yet.

		 */

		vmx->nested.need_vmcs12_sync = true;

	} else {

		return -EINVAL;

	}



	if (kvm_state->vmx.smm.flags & KVM_STATE_NESTED_SMM_VMXON) {

		vmx->nested.smm.vmxon = true;

arch/x86/kvm/x86.c

+4 −2
Original line number Diff line number Diff line
@@ -4068,11 +4068,13 @@ long kvm_arch_vcpu_ioctl(struct file *filp, 
			break;



		if (kvm_state.flags &

		    ~(KVM_STATE_NESTED_RUN_PENDING | KVM_STATE_NESTED_GUEST_MODE))

		    ~(KVM_STATE_NESTED_RUN_PENDING | KVM_STATE_NESTED_GUEST_MODE

		      | KVM_STATE_NESTED_EVMCS))

			break;



		/* nested_run_pending implies guest_mode.  */

		if (kvm_state.flags == KVM_STATE_NESTED_RUN_PENDING)

		if ((kvm_state.flags & KVM_STATE_NESTED_RUN_PENDING)

		    && !(kvm_state.flags & KVM_STATE_NESTED_GUEST_MODE))

			break;



		r = kvm_x86_ops->set_nested_state(vcpu, user_kvm_nested_state, &kvm_state);

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