[PATCH v4 6/7] x86: KVM: svm: eliminate weird goto from vmrun_interception()

[Vitaly Kuznetsov]

Regardless of whether or not nested_svm_vmrun_msrpm() fails, we return 1
from vmrun_interception() so there's no point in doing goto. Also,
nested_svm_vmrun_msrpm() call can be made from nested_svm_vmrun() where
other nested launch issues are handled.

nested_svm_vmrun() returns a bool, however, its result is ignored in
vmrun_interception() as we always return '1'. As a preparatory change
to putting kvm_skip_emulated_instruction() inside nested_svm_vmrun()
make nested_svm_vmrun() return an int (always '1' for now).

Suggested-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
 arch/x86/kvm/svm.c | 36 ++++++++++++++----------------------
 1 file changed, 14 insertions(+), 22 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 6d16d1898810..51c39b608ef7 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3586,7 +3586,7 @@ static void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,
 	mark_all_dirty(svm->vmcb);
 }
 
-static bool nested_svm_vmrun(struct vcpu_svm *svm)
+static int nested_svm_vmrun(struct vcpu_svm *svm)
 {
 	int rc;
 	struct vmcb *nested_vmcb;
@@ -3601,7 +3601,7 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)
 	if (rc) {
 		if (rc == -EINVAL)
 			kvm_inject_gp(&svm->vcpu, 0);
-		return false;
+		return 1;
 	}
 
 	nested_vmcb = map.hva;
@@ -3614,7 +3614,7 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)
 
 		kvm_vcpu_unmap(&svm->vcpu, &map, true);
 
-		return false;
+		return 1;
 	}
 
 	trace_kvm_nested_vmrun(svm->vmcb->save.rip, vmcb_gpa,
@@ -3658,7 +3658,16 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)
 
 	enter_svm_guest_mode(svm, vmcb_gpa, nested_vmcb, &map);
 
-	return true;
+	if (!nested_svm_vmrun_msrpm(svm)) {
+		svm->vmcb->control.exit_code    = SVM_EXIT_ERR;
+		svm->vmcb->control.exit_code_hi = 0;
+		svm->vmcb->control.exit_info_1  = 0;
+		svm->vmcb->control.exit_info_2  = 0;
+
+		nested_svm_vmexit(svm);
+	}
+
+	return 1;
 }
 
 static void nested_svm_vmloadsave(struct vmcb *from_vmcb, struct vmcb *to_vmcb)
@@ -3737,24 +3746,7 @@ static int vmrun_interception(struct vcpu_svm *svm)
 	/* Save rip after vmrun instruction */
 	kvm_rip_write(&svm->vcpu, kvm_rip_read(&svm->vcpu) + 3);
 
-	if (!nested_svm_vmrun(svm))
-		return 1;
-
-	if (!nested_svm_vmrun_msrpm(svm))
-		goto failed;
-
-	return 1;
-
-failed:
-
-	svm->vmcb->control.exit_code    = SVM_EXIT_ERR;
-	svm->vmcb->control.exit_code_hi = 0;
-	svm->vmcb->control.exit_info_1  = 0;
-	svm->vmcb->control.exit_info_2  = 0;
-
-	nested_svm_vmexit(svm);
-
-	return 1;
+	return nested_svm_vmrun(svm);
 }
 
 static int stgi_interception(struct vcpu_svm *svm)
-- 
2.20.1