[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.christopher...@intel.com>
Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com>
---
 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