KVM: x86 emulator: Make x86_decode_insn() return proper macros

Return EMULATION_OK/FAILED consistently.  Also treat instruction fetch
errors, not restricted to X86EMUL_UNHANDLEABLE, as EMULATION_FAILED;
although this cannot happen in practice, the current logic will continue
the emulation even if the decoder fails to fetch the instruction.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>

2 files changed, 7 insertions, 7 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 191bc9be4946..fe5eb6d9b3e1 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3373,7 +3373,7 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
                 break;
 #endif
         default:
-                return -1;
+                return EMULATION_FAILED;
         }
 
         ctxt->op_bytes = def_op_bytes;
@@ -3465,7 +3465,7 @@ done_prefixes:
                         break;
                 case Prefix:
                         if (ctxt->rep_prefix && op_prefix)
-                                return X86EMUL_UNHANDLEABLE;
+                                return EMULATION_FAILED;
                         simd_prefix = op_prefix ? 0x66 : ctxt->rep_prefix;
                         switch (simd_prefix) {
                         case 0x00: opcode = opcode.u.gprefix->pfx_no; break;
@@ -3475,7 +3475,7 @@ done_prefixes:
                         }
                         break;
                 default:
-                        return X86EMUL_UNHANDLEABLE;
+                        return EMULATION_FAILED;
                 }
 
                 ctxt->d &= ~GroupMask;
@@ -3488,10 +3488,10 @@ done_prefixes:
 
         /* Unrecognised? */
         if (ctxt->d == 0 || (ctxt->d & Undefined))
-                return -1;
+                return EMULATION_FAILED;
 
         if (!(ctxt->d & VendorSpecific) && ctxt->only_vendor_specific_insn)
-                return -1;
+                return EMULATION_FAILED;
 
         if (mode == X86EMUL_MODE_PROT64 && (ctxt->d & Stack))
                 ctxt->op_bytes = 8;
@@ -3683,7 +3683,7 @@ done:
         if (memopp && memopp->type == OP_MEM && ctxt->rip_relative)
                 memopp->addr.mem.ea += ctxt->_eip;
 
-        return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
+        return (rc != X86EMUL_CONTINUE) ? EMULATION_FAILED : EMULATION_OK;
 }
 
 static bool string_insn_completed(struct x86_emulate_ctxt *ctxt)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d28dff749dfd..1fe9637ff153 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4837,7 +4837,7 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu,
 
                 trace_kvm_emulate_insn_start(vcpu);
                 ++vcpu->stat.insn_emulation;
-                if (r)  {
+                if (r != EMULATION_OK)  {
                         if (emulation_type & EMULTYPE_TRAP_UD)
                                 return EMULATE_FAIL;
                         if (reexecute_instruction(vcpu, cr2))