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>

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 191bc9b..fe5eb6d 100644 (file)
--- 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 d28dff7..1fe9637 100644 (file)
--- 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))