[RESEND PATCH 12/13] KVM: VMX: Remove EMULATE_FAIL handling in handle_invalid_guest_state()

[Sean Christopherson]

Now that EMULATE_FAIL is completely unused, remove the last remaning
usage where KVM does something functional in response to EMULATE_FAIL.
Leave the check in place as a WARN_ON_ONCE to provide a better paper
trail when EMULATE_{DONE,FAIL,USER_EXIT} are completely removed.

Opportunistically remove the gotos in handle_invalid_guest_state().
With the EMULATE_FAIL handling gone there is no need to have a common
handler for emulation failure and the gotos only complicate things,
e.g. the signal_pending() check always returns '1', but this is far
from obvious when glancing through the code.

Signed-off-by: Sean Christopherson <sean.j.christopher...@intel.com>
---
 arch/x86/kvm/vmx/vmx.c | 39 +++++++++++++++++++--------------------
 1 file changed, 19 insertions(+), 20 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index efc2f913ca19..5b5f622cc092 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5164,7 +5164,6 @@ static int handle_invalid_guest_state(struct kvm_vcpu 
*vcpu)
 {
        struct vcpu_vmx *vmx = to_vmx(vcpu);
        enum emulation_result err = EMULATE_DONE;
-       int ret = 1;
        bool intr_window_requested;
        unsigned count = 130;
 
@@ -5187,38 +5186,38 @@ static int handle_invalid_guest_state(struct kvm_vcpu 
*vcpu)
 
                err = kvm_emulate_instruction(vcpu, 0);
 
-               if (err == EMULATE_USER_EXIT) {
-                       ret = 0;
-                       goto out;
-               }
+               if (err == EMULATE_USER_EXIT)
+                       return 0;
 
-               if (err != EMULATE_DONE)
-                       goto emulation_error;
+               if (WARN_ON_ONCE(err == EMULATE_FAIL))
+                       return 1;
 
                if (vmx->emulation_required && !vmx->rmode.vm86_active &&
-                   vcpu->arch.exception.pending)
-                       goto emulation_error;
+                   vcpu->arch.exception.pending) {
+                       vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+                       vcpu->run->internal.suberror =
+                                               KVM_INTERNAL_ERROR_EMULATION;
+                       vcpu->run->internal.ndata = 0;
+                       return 0;
+               }
 
                if (vcpu->arch.halt_request) {
                        vcpu->arch.halt_request = 0;
-                       ret = kvm_vcpu_halt(vcpu);
-                       goto out;
+                       return kvm_vcpu_halt(vcpu);
                }
 
+               /*
+                * Note, return 1 and not 0, vcpu_run() is responsible for
+                * morphing the pending signal into the proper return code.
+                */
                if (signal_pending(current))
-                       goto out;
+                       return 1;
+
                if (need_resched())
                        schedule();
        }
 
-out:
-       return ret;
-
-emulation_error:
-       vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
-       vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION;
-       vcpu->run->internal.ndata = 0;
-       return 0;
+       return 1;
 }
 
 static void grow_ple_window(struct kvm_vcpu *vcpu)
-- 
2.22.0