[PATCH v3 17/27] KVM: nSVM: Always switch VMCB before leaving guest mode

[Yosry Ahmed]

Move svm_switch_vmcb() calls ahead of leave_guest_mode(), as nothing
between the calls depends on svm->vmcb being set to vmcb01. This makes
the nested VM-Exit path consistent with the nested VM-Enter path, and
having the calls to svm_switch_vmcb() and leave_guest_mode() close makes
it easier to reason about incoming changes that depend on both VMCB and
guest_mode context.

No functional change intended.

Signed-off-by: Yosry Ahmed <yosry@xxxxxxxxxx>
---
 arch/x86/kvm/svm/nested.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 75ada771026b2..27f78228a42d5 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -1329,7 +1329,7 @@ void nested_svm_vmexit(struct vcpu_svm *svm)
 	if (nested_svm_vmexit_update_vmcb12(vcpu))
 		kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
 
-	/* Exit Guest-Mode */
+	svm_switch_vmcb(svm, &svm->vmcb01);
 	leave_guest_mode(vcpu);
 	svm_pmu_handle_nested_transition(svm);
 
@@ -1356,8 +1356,6 @@ void nested_svm_vmexit(struct vcpu_svm *svm)
 	if (guest_cpu_cap_has(vcpu, X86_FEATURE_ERAPS))
 		vmcb01->control.erap_ctl |= ERAP_CONTROL_CLEAR_RAP;
 
-	svm_switch_vmcb(svm, &svm->vmcb01);
-
 	/*
 	 * Rules for synchronizing int_ctl bits from vmcb02 to vmcb01:
 	 *
@@ -1543,6 +1541,7 @@ void svm_leave_nested(struct kvm_vcpu *vcpu)
 		vcpu->arch.nested_run_pending = 0;
 		svm->nested.vmcb12_gpa = INVALID_GPA;
 
+		svm_switch_vmcb(svm, &svm->vmcb01);
 		leave_guest_mode(vcpu);
 
 		/*
@@ -1554,8 +1553,6 @@ void svm_leave_nested(struct kvm_vcpu *vcpu)
 		 */
 		__svm_pmu_handle_nested_transition(svm, true);
 
-		svm_switch_vmcb(svm, &svm->vmcb01);
-
 		nested_svm_transition_tlb_flush(vcpu);
 
 		nested_svm_uninit_mmu_context(vcpu);
-- 
2.56.0.385.gd3acb90ef8-goog