KVM: nVMX: Introduce helpers to check if Hyper-V evmptr12 is valid/set

In order to get rid of raw 'vmx->nested.hv_evmcs_vmptr' accesses when
!CONFIG_KVM_HYPERV, introduce a pair of helpers:

nested_vmx_is_evmptr12_valid() to check that eVMPTR points to a valid
address.

nested_vmx_is_evmptr12_valid() to check that eVMPTR either points to a
valid address or is in 'pending' port-migration state (meaning it is
supposed to be valid but the exact address wasn't acquired from guest's
memory yet).

No functional change intended.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Tested-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Link: https://lore.kernel.org/r/20231205103630.1391318-14-vkuznets@redhat.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: vittyvk

arch/x86/kvm/vmx/hyperv.h

@@ -22,6 +22,21 @@ static inline bool evmptr_is_valid(u64 evmptr)
 	return evmptr != EVMPTR_INVALID && evmptr != EVMPTR_MAP_PENDING;
 }
 
+static inline bool nested_vmx_is_evmptr12_valid(struct vcpu_vmx *vmx)
+{
+	return evmptr_is_valid(vmx->nested.hv_evmcs_vmptr);
+}
+
+static inline bool evmptr_is_set(u64 evmptr)
+{
+	return evmptr != EVMPTR_INVALID;
+}
+
+static inline bool nested_vmx_is_evmptr12_set(struct vcpu_vmx *vmx)
+{
+	return evmptr_is_set(vmx->nested.hv_evmcs_vmptr);
+}
+
 static inline bool guest_cpuid_has_evmcs(struct kvm_vcpu *vcpu)
 {
 	/*
@@ -45,6 +60,21 @@ static inline bool evmptr_is_valid(u64 evmptr)
 {
 	return false;
 }
+
+static inline bool nested_vmx_is_evmptr12_valid(struct vcpu_vmx *vmx)
+{
+	return false;
+}
+
+static inline bool evmptr_is_set(u64 evmptr)
+{
+	return false;
+}
+
+static inline bool nested_vmx_is_evmptr12_set(struct vcpu_vmx *vmx)
+{
+	return false;
+}
 #endif
 
 #endif /* __KVM_X86_VMX_HYPERV_H */

arch/x86/kvm/vmx/nested.c

@@ -179,7 +179,7 @@ static int nested_vmx_failValid(struct kvm_vcpu *vcpu,
 	 * VM_INSTRUCTION_ERROR is not shadowed. Enlightened VMCS 'shadows' all
 	 * fields and thus must be synced.
 	 */
-	if (to_vmx(vcpu)->nested.hv_evmcs_vmptr != EVMPTR_INVALID)
+	if (nested_vmx_is_evmptr12_set(to_vmx(vcpu)))
 		to_vmx(vcpu)->nested.need_vmcs12_to_shadow_sync = true;
 
 	return kvm_skip_emulated_instruction(vcpu);
@@ -194,7 +194,7 @@ static int nested_vmx_fail(struct kvm_vcpu *vcpu, u32 vm_instruction_error)
 	 * can't be done if there isn't a current VMCS.
 	 */
 	if (vmx->nested.current_vmptr == INVALID_GPA &&
-	    !evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
+	    !nested_vmx_is_evmptr12_valid(vmx))
 		return nested_vmx_failInvalid(vcpu);
 
 	return nested_vmx_failValid(vcpu, vm_instruction_error);
@@ -230,7 +230,7 @@ static inline void nested_release_evmcs(struct kvm_vcpu *vcpu)
 	struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 
-	if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)) {
+	if (nested_vmx_is_evmptr12_valid(vmx)) {
 		kvm_vcpu_unmap(vcpu, &vmx->nested.hv_evmcs_map, true);
 		vmx->nested.hv_evmcs = NULL;
 	}
@@ -2123,7 +2123,7 @@ void nested_sync_vmcs12_to_shadow(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 
-	if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
+	if (nested_vmx_is_evmptr12_valid(vmx))
 		copy_vmcs12_to_enlightened(vmx);
 	else
 		copy_vmcs12_to_shadow(vmx);
@@ -2277,7 +2277,7 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct loaded_vmcs *vmcs0
 	u32 exec_control;
 	u64 guest_efer = nested_vmx_calc_efer(vmx, vmcs12);
 
-	if (vmx->nested.dirty_vmcs12 || evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
+	if (vmx->nested.dirty_vmcs12 || nested_vmx_is_evmptr12_valid(vmx))
 		prepare_vmcs02_early_rare(vmx, vmcs12);
 
 	/*
@@ -2572,11 +2572,11 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	bool load_guest_pdptrs_vmcs12 = false;
 
-	if (vmx->nested.dirty_vmcs12 || evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)) {
+	if (vmx->nested.dirty_vmcs12 || nested_vmx_is_evmptr12_valid(vmx)) {
 		prepare_vmcs02_rare(vmx, vmcs12);
 		vmx->nested.dirty_vmcs12 = false;
 
-		load_guest_pdptrs_vmcs12 = !evmptr_is_valid(vmx->nested.hv_evmcs_vmptr) ||
+		load_guest_pdptrs_vmcs12 = !nested_vmx_is_evmptr12_valid(vmx) ||
 			!(vmx->nested.hv_evmcs->hv_clean_fields &
 			  HV_VMX_ENLIGHTENED_CLEAN_FIELD_GUEST_GRP1);
 	}
@@ -2699,7 +2699,7 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
 	 * bits when it changes a field in eVMCS. Mark all fields as clean
 	 * here.
 	 */
-	if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
+	if (nested_vmx_is_evmptr12_valid(vmx))
 		vmx->nested.hv_evmcs->hv_clean_fields |=
 			HV_VMX_ENLIGHTENED_CLEAN_FIELD_ALL;
 
@@ -3579,7 +3579,7 @@ enum nvmx_vmentry_status nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu,
 
 	load_vmcs12_host_state(vcpu, vmcs12);
 	vmcs12->vm_exit_reason = exit_reason.full;
-	if (enable_shadow_vmcs || evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
+	if (enable_shadow_vmcs || nested_vmx_is_evmptr12_valid(vmx))
 		vmx->nested.need_vmcs12_to_shadow_sync = true;
 	return NVMX_VMENTRY_VMEXIT;
 }
@@ -3610,7 +3610,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
 	if (CC(evmptrld_status == EVMPTRLD_VMFAIL))
 		return nested_vmx_failInvalid(vcpu);
 
-	if (CC(!evmptr_is_valid(vmx->nested.hv_evmcs_vmptr) &&
+	if (CC(!nested_vmx_is_evmptr12_valid(vmx) &&
 	       vmx->nested.current_vmptr == INVALID_GPA))
 		return nested_vmx_failInvalid(vcpu);
 
@@ -3625,7 +3625,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
 	if (CC(vmcs12->hdr.shadow_vmcs))
 		return nested_vmx_failInvalid(vcpu);
 
-	if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)) {
+	if (nested_vmx_is_evmptr12_valid(vmx)) {
 		copy_enlightened_to_vmcs12(vmx, vmx->nested.hv_evmcs->hv_clean_fields);
 		/* Enlightened VMCS doesn't have launch state */
 		vmcs12->launch_state = !launch;
@@ -4370,11 +4370,11 @@ static void sync_vmcs02_to_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 
-	if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
+	if (nested_vmx_is_evmptr12_valid(vmx))
 		sync_vmcs02_to_vmcs12_rare(vcpu, vmcs12);
 
 	vmx->nested.need_sync_vmcs02_to_vmcs12_rare =
-		!evmptr_is_valid(vmx->nested.hv_evmcs_vmptr);
+		!nested_vmx_is_evmptr12_valid(vmx);
 
 	vmcs12->guest_cr0 = vmcs12_guest_cr0(vcpu, vmcs12);
 	vmcs12->guest_cr4 = vmcs12_guest_cr4(vcpu, vmcs12);
@@ -4897,7 +4897,7 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 vm_exit_reason,
 	}
 
 	if ((vm_exit_reason != -1) &&
-	    (enable_shadow_vmcs || evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)))
+	    (enable_shadow_vmcs || nested_vmx_is_evmptr12_valid(vmx)))
 		vmx->nested.need_vmcs12_to_shadow_sync = true;
 
 	/* in case we halted in L2 */
@@ -5390,7 +5390,7 @@ static int handle_vmread(struct kvm_vcpu *vcpu)
 	/* Decode instruction info and find the field to read */
 	field = kvm_register_read(vcpu, (((instr_info) >> 28) & 0xf));
 
-	if (!evmptr_is_valid(vmx->nested.hv_evmcs_vmptr)) {
+	if (!nested_vmx_is_evmptr12_valid(vmx)) {
 		/*
 		 * In VMX non-root operation, when the VMCS-link pointer is INVALID_GPA,
 		 * any VMREAD sets the ALU flags for VMfailInvalid.
@@ -5616,7 +5616,7 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu)
 		return nested_vmx_fail(vcpu, VMXERR_VMPTRLD_VMXON_POINTER);
 
 	/* Forbid normal VMPTRLD if Enlightened version was used */
-	if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
+	if (nested_vmx_is_evmptr12_valid(vmx))
 		return 1;
 
 	if (vmx->nested.current_vmptr != vmptr) {
@@ -5679,7 +5679,7 @@ static int handle_vmptrst(struct kvm_vcpu *vcpu)
 	if (!nested_vmx_check_permission(vcpu))
 		return 1;
 
-	if (unlikely(evmptr_is_valid(to_vmx(vcpu)->nested.hv_evmcs_vmptr)))
+	if (unlikely(nested_vmx_is_evmptr12_valid(to_vmx(vcpu))))
 		return 1;
 
 	if (get_vmx_mem_address(vcpu, exit_qual, instr_info,
@@ -6467,7 +6467,7 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu,
 			kvm_state.size += sizeof(user_vmx_nested_state->vmcs12);
 
 			/* 'hv_evmcs_vmptr' can also be EVMPTR_MAP_PENDING here */
-			if (vmx->nested.hv_evmcs_vmptr != EVMPTR_INVALID)
+			if (nested_vmx_is_evmptr12_set(vmx))
 				kvm_state.flags |= KVM_STATE_NESTED_EVMCS;
 
 			if (is_guest_mode(vcpu) &&
@@ -6523,7 +6523,7 @@ static int vmx_get_nested_state(struct kvm_vcpu *vcpu,
 	} else  {
 		copy_vmcs02_to_vmcs12_rare(vcpu, get_vmcs12(vcpu));
 		if (!vmx->nested.need_vmcs12_to_shadow_sync) {
-			if (evmptr_is_valid(vmx->nested.hv_evmcs_vmptr))
+			if (nested_vmx_is_evmptr12_valid(vmx))
 				/*
 				 * L1 hypervisor is not obliged to keep eVMCS
 				 * clean fields data always up-to-date while

arch/x86/kvm/vmx/nested.h

@@ -58,7 +58,7 @@ static inline int vmx_has_valid_vmcs12(struct kvm_vcpu *vcpu)
 
 	/* 'hv_evmcs_vmptr' can also be EVMPTR_MAP_PENDING here */
 	return vmx->nested.current_vmptr != -1ull ||
-		vmx->nested.hv_evmcs_vmptr != EVMPTR_INVALID;
+		nested_vmx_is_evmptr12_set(vmx);
 }
 
 static inline u16 nested_get_vpid02(struct kvm_vcpu *vcpu)