KVM: nSVM: extract load_nested_vmcb_control

When restoring SVM nested state, the control state cache in svm->nested
will have to be filled, but the save state will not have to be moved
into svm->vmcb.  Therefore, pull the code that handles the control area
into a separate function.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm/nested.c

@@ -228,6 +228,23 @@ static bool nested_vmcb_checks(struct vmcb *vmcb)
 	return true;
 }
 
+static void load_nested_vmcb_control(struct vcpu_svm *svm,
+				     struct vmcb_control_area *control)
+{
+	svm->nested.nested_cr3 = control->nested_cr3;
+
+	svm->nested.vmcb_msrpm = control->msrpm_base_pa & ~0x0fffULL;
+	svm->nested.vmcb_iopm  = control->iopm_base_pa  & ~0x0fffULL;
+
+	/* cache intercepts */
+	svm->nested.intercept_cr         = control->intercept_cr;
+	svm->nested.intercept_dr         = control->intercept_dr;
+	svm->nested.intercept_exceptions = control->intercept_exceptions;
+	svm->nested.intercept            = control->intercept;
+
+	svm->vcpu.arch.tsc_offset += control->tsc_offset;
+}
+
 void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
 			  struct vmcb *nested_vmcb)
 {
@@ -235,15 +252,16 @@ void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
 		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;
 
-	if (nested_vmcb->control.nested_ctl & SVM_NESTED_CTL_NP_ENABLE) {
-		svm->nested.nested_cr3 = nested_vmcb->control.nested_cr3;
+	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);
-	}
 
 	/* Load the nested guest state */
 	svm->vmcb->save.es = nested_vmcb->save.es;
@@ -274,25 +292,15 @@ void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
 	svm->vcpu.arch.dr6  = nested_vmcb->save.dr6;
 	svm->vmcb->save.cpl = nested_vmcb->save.cpl;
 
-	svm->nested.vmcb_msrpm = nested_vmcb->control.msrpm_base_pa & ~0x0fffULL;
-	svm->nested.vmcb_iopm  = nested_vmcb->control.iopm_base_pa  & ~0x0fffULL;
-
-	/* cache intercepts */
-	svm->nested.intercept_cr         = nested_vmcb->control.intercept_cr;
-	svm->nested.intercept_dr         = nested_vmcb->control.intercept_dr;
-	svm->nested.intercept_exceptions = nested_vmcb->control.intercept_exceptions;
-	svm->nested.intercept            = nested_vmcb->control.intercept;
-
 	svm_flush_tlb(&svm->vcpu);
-	svm->vmcb->control.int_ctl = nested_vmcb->control.int_ctl | V_INTR_MASKING_MASK;
 	if (nested_vmcb->control.int_ctl & V_INTR_MASKING_MASK)
 		svm->vcpu.arch.hflags |= HF_VINTR_MASK;
 	else
 		svm->vcpu.arch.hflags &= ~HF_VINTR_MASK;
 
-	svm->vcpu.arch.tsc_offset += nested_vmcb->control.tsc_offset;
 	svm->vmcb->control.tsc_offset = svm->vcpu.arch.tsc_offset;
 
+	svm->vmcb->control.int_ctl = nested_vmcb->control.int_ctl | V_INTR_MASKING_MASK;
 	svm->vmcb->control.virt_ext = nested_vmcb->control.virt_ext;
 	svm->vmcb->control.int_vector = nested_vmcb->control.int_vector;
 	svm->vmcb->control.int_state = nested_vmcb->control.int_state;
@@ -313,8 +321,6 @@ void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
 	 */
 	recalc_intercepts(svm);
 
-	svm->nested.vmcb = vmcb_gpa;
-
 	/*
 	 * If L1 had a pending IRQ/NMI before executing VMRUN,
 	 * which wasn't delivered because it was disallowed (e.g.