[RESEND PATCH 08/13] KVM: x86: Move #UD injection for failed emulation into emulation code

[Sean Christopherson]

Immediately inject a #UD and return EMULATE done if emulation fails when
handling an intercepted #UD.  This helps pave the way for removing
EMULATE_FAIL altogether.

Signed-off-by: Sean Christopherson <sean.j.christopher...@intel.com>
---
 arch/x86/kvm/x86.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a1f9e36b2d58..bff3320aa78e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5328,7 +5328,6 @@ EXPORT_SYMBOL_GPL(kvm_write_guest_virt_system);
 int handle_ud(struct kvm_vcpu *vcpu)
 {
        int emul_type = EMULTYPE_TRAP_UD;
-       enum emulation_result er;
        char sig[5]; /* ud2; .ascii "kvm" */
        struct x86_exception e;
 
@@ -5340,12 +5339,7 @@ int handle_ud(struct kvm_vcpu *vcpu)
                emul_type = EMULTYPE_TRAP_UD_FORCED;
        }
 
-       er = kvm_emulate_instruction(vcpu, emul_type);
-       if (er == EMULATE_USER_EXIT)
-               return 0;
-       if (er != EMULATE_DONE)
-               kvm_queue_exception(vcpu, UD_VECTOR);
-       return 1;
+       return kvm_emulate_instruction(vcpu, emul_type) != EMULATE_USER_EXIT;
 }
 EXPORT_SYMBOL_GPL(handle_ud);
 
@@ -6533,8 +6527,10 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu,
                ++vcpu->stat.insn_emulation;
                if (r != EMULATION_OK)  {
                        if ((emulation_type & EMULTYPE_TRAP_UD) ||
-                           (emulation_type & EMULTYPE_TRAP_UD_FORCED))
-                               return EMULATE_FAIL;
+                           (emulation_type & EMULTYPE_TRAP_UD_FORCED)) {
+                               kvm_queue_exception(vcpu, UD_VECTOR);
+                               return EMULATE_DONE;
+                       }
                        if (reexecute_instruction(vcpu, cr2, write_fault_to_spt,
                                                emulation_type))
                                return EMULATE_DONE;
-- 
2.22.0