KVM: nSVM: extract preparation of VMCB for nested run

Split out filling svm->vmcb.save and svm->vmcb.control before VMRUN.
Only the latter will be useful when restoring nested SVM state.

This patch introduces no semantic change, so the MMU setup is still
done in nested_prepare_vmcb_save.  The next patch will clean up things.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm/nested.c

@@ -245,21 +245,8 @@ static void load_nested_vmcb_control(struct vcpu_svm *svm,
 	svm->vcpu.arch.tsc_offset += control->tsc_offset;
 }
 
-void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
-			  struct vmcb *nested_vmcb)
+static void nested_prepare_vmcb_save(struct vcpu_svm *svm, struct vmcb *nested_vmcb)
 {
-	bool evaluate_pending_interrupts =
-		is_intercept(svm, INTERCEPT_VINTR) ||
-		is_intercept(svm, INTERCEPT_IRET);
-
-	svm->nested.vmcb = vmcb_gpa;
-	if (kvm_get_rflags(&svm->vcpu) & X86_EFLAGS_IF)
-		svm->vcpu.arch.hflags |= HF_HIF_MASK;
-	else
-		svm->vcpu.arch.hflags &= ~HF_HIF_MASK;
-
-	load_nested_vmcb_control(svm, &nested_vmcb->control);
-
 	if (nested_vmcb->control.nested_ctl & SVM_NESTED_CTL_NP_ENABLE)
 		nested_svm_init_mmu_context(&svm->vcpu);
 
@@ -291,7 +278,10 @@ void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
 	svm->vmcb->save.dr7 = nested_vmcb->save.dr7;
 	svm->vcpu.arch.dr6  = nested_vmcb->save.dr6;
 	svm->vmcb->save.cpl = nested_vmcb->save.cpl;
+}
 
+static void nested_prepare_vmcb_control(struct vcpu_svm *svm, struct vmcb *nested_vmcb)
+{
 	svm_flush_tlb(&svm->vcpu);
 	if (nested_vmcb->control.int_ctl & V_INTR_MASKING_MASK)
 		svm->vcpu.arch.hflags |= HF_VINTR_MASK;
@@ -321,6 +311,26 @@ void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
 	 */
 	recalc_intercepts(svm);
 
+	mark_all_dirty(svm->vmcb);
+}
+
+void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
+			  struct vmcb *nested_vmcb)
+{
+	bool evaluate_pending_interrupts =
+		is_intercept(svm, INTERCEPT_VINTR) ||
+		is_intercept(svm, INTERCEPT_IRET);
+
+	svm->nested.vmcb = vmcb_gpa;
+	if (kvm_get_rflags(&svm->vcpu) & X86_EFLAGS_IF)
+		svm->vcpu.arch.hflags |= HF_HIF_MASK;
+	else
+		svm->vcpu.arch.hflags &= ~HF_HIF_MASK;
+
+	load_nested_vmcb_control(svm, &nested_vmcb->control);
+	nested_prepare_vmcb_save(svm, nested_vmcb);
+	nested_prepare_vmcb_control(svm, nested_vmcb);
+
 	/*
 	 * If L1 had a pending IRQ/NMI before executing VMRUN,
 	 * which wasn't delivered because it was disallowed (e.g.
@@ -336,8 +346,6 @@ void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
 	enable_gif(svm);
 	if (unlikely(evaluate_pending_interrupts))
 		kvm_make_request(KVM_REQ_EVENT, &svm->vcpu);
-
-	mark_all_dirty(svm->vmcb);
 }
 
 int nested_svm_vmrun(struct vcpu_svm *svm)