KVM: x86: Move #GP injection for VMware into x86_emulate_instruction()

Immediately inject a #GP when VMware emulation fails and return
EMULATE_DONE instead of propagating EMULATE_FAIL up the stack.  This
helps pave the way for removing EMULATE_FAIL altogether.

Rename EMULTYPE_VMWARE to EMULTYPE_VMWARE_GP to document that the x86
emulator is called to handle VMware #GP interception, e.g. why a #GP
is injected on emulation failure for EMULTYPE_VMWARE_GP.

Drop EMULTYPE_NO_UD_ON_FAIL as a standalone type.  The "no #UD on fail"
is used only in the VMWare case and is obsoleted by having the emulator
itself reinject #GP.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e6063f2..09753b6 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6307,8 +6307,10 @@ static int handle_emulation_failure(struct kvm_vcpu *vcpu, int emulation_type)
 	++vcpu->stat.insn_emulation_fail;
 	trace_kvm_emulate_insn_failed(vcpu);
 
-	if (emulation_type & EMULTYPE_NO_UD_ON_FAIL)
-		return EMULATE_FAIL;
+	if (emulation_type & EMULTYPE_VMWARE_GP) {
+		kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
+		return EMULATE_DONE;
+	}
 
 	kvm_queue_exception(vcpu, UD_VECTOR);
 
@@ -6648,9 +6650,11 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu,
 		}
 	}
 
-	if ((emulation_type & EMULTYPE_VMWARE) &&
-	    !is_vmware_backdoor_opcode(ctxt))
-		return EMULATE_FAIL;
+	if ((emulation_type & EMULTYPE_VMWARE_GP) &&
+	    !is_vmware_backdoor_opcode(ctxt)) {
+		kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
+		return EMULATE_DONE;
+	}
 
 	if (emulation_type & EMULTYPE_SKIP) {
 		kvm_rip_write(vcpu, ctxt->_eip);