KVM: x86 emulator: Make a distinction between repeat prefixes F3 and F2

cmps and scas instructions accept repeat prefixes F3 and F2. So in
order to emulate those prefixed instructions we need to be able to know
if prefixes are REP/REPE/REPZ or REPNE/REPNZ. Currently kvm doesn't make
this distinction. This patch introduces this distinction.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>

diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index 6e7f774d17513beaf272cc311c387ddd6d94e652..9f8d59a49313d1d5e50299be1afdc6c4cf79eef5 100644 (file)
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -824,8 +824,10 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
                        c->lock_prefix = 1;
                        break;
                case 0xf2:      /* REPNE/REPNZ */
+                       c->rep_prefix = REPNE_PREFIX;
+                       break;
                case 0xf3:      /* REP/REPE/REPZ */
-                       c->rep_prefix = 1;
+                       c->rep_prefix = REPE_PREFIX;
                        break;
                default:
                        goto done_prefixes;

diff --git a/drivers/kvm/x86_emulate.h b/drivers/kvm/x86_emulate.h
index 4603b2bf34880a007f19146b8b6b1578716069e8..644086e354a7001d19f4d2ea90fcc56e361e3828 100644 (file)
--- a/drivers/kvm/x86_emulate.h
+++ b/drivers/kvm/x86_emulate.h
@@ -162,6 +162,10 @@ struct x86_emulate_ctxt {
        struct decode_cache decode;
 };
 
+/* Repeat String Operation Prefix */
+#define REPE_PREFIX  1
+#define REPNE_PREFIX    2
+
 /* Execution mode, passed to the emulator. */
 #define X86EMUL_MODE_REAL     0        /* Real mode.             */
 #define X86EMUL_MODE_PROT16   2        /* 16-bit protected mode. */