Move all groups into a single field and handle them in a single place. This
saves bits when we add more group types (3 bits -> 7 groups types).
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
---
arch/x86/kvm/emulate.c | 80 ++++++++++++++++++++++++------------------------
1 files changed, 40 insertions(+), 40 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index e8635ca..d6a8b95 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -73,11 +73,12 @@
#define MemAbs (1<<11) /* Memory operand is absolute displacement */
#define String (1<<12) /* String instruction (rep capable) */
#define Stack (1<<13) /* Stack instruction (push/pop) */
+#define GroupMask (7<<14) /* Opcode uses one of the group mechanisms */
#define Group (1<<14) /* Bits 3:5 of modrm byte extend opcode */
-#define GroupDual (1<<15) /* Alternate decoding of mod == 3 */
-#define Prefix (1<<16) /* Instruction varies with 66/f2/f3 prefix */
+#define GroupDual (2<<14) /* Alternate decoding of mod == 3 */
+#define Prefix (3<<14) /* Instruction varies with 66/f2/f3 prefix */
+#define RMExt (4<<14) /* Opcode extension in ModRM r/m if mod == 3 */
#define Sse (1<<17) /* SSE Vector instruction */
-#define RMExt (1<<18) /* Opcode extension in ModRM r/m if mod == 3 */
/* Misc flags */
#define Prot (1<<21) /* instruction generates #UD if not in prot-mode */
#define VendorSpecific (1<<22) /* Vendor specific instruction */
@@ -2969,7 +2970,7 @@ static int check_perm_out(struct x86_emulate_ctxt *ctxt)
#define N D(0)
#define EXT(_f, _e) { .flags = ((_f) | RMExt), .u.group = (_e) }
#define G(_f, _g) { .flags = ((_f) | Group), .u.group = (_g) }
-#define GD(_f, _g) { .flags = ((_f) | Group | GroupDual), .u.gdual = (_g) }
+#define GD(_f, _g) { .flags = ((_f) | GroupDual), .u.gdual = (_g) }
#define I(_f, _e) { .flags = (_f), .u.execute = (_e) }
#define II(_f, _e, _i) \
{ .flags = (_f), .u.execute = (_e), .intercept = x86_intercept_##_i }
@@ -3337,9 +3338,9 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
struct decode_cache *c = &ctxt->decode;
int rc = X86EMUL_CONTINUE;
int mode = ctxt->mode;
- int def_op_bytes, def_ad_bytes, dual, goffset, simd_prefix;
+ int def_op_bytes, def_ad_bytes, goffset, simd_prefix;
bool op_prefix = false;
- struct opcode opcode, *g_mod012, *g_mod3;
+ struct opcode opcode;
struct operand memop = { .type = OP_NONE };
c->eip = ctxt->eip;
@@ -3433,44 +3434,43 @@ done_prefixes:
}
c->d = opcode.flags;
- if (c->d & Group) {
- dual = c->d & GroupDual;
- c->modrm = insn_fetch(u8, 1, c->eip);
- --c->eip;
-
- if (c->d & GroupDual) {
- g_mod012 = opcode.u.gdual->mod012;
- g_mod3 = opcode.u.gdual->mod3;
- } else
- g_mod012 = g_mod3 = opcode.u.group;
-
- c->d &= ~(Group | GroupDual);
-
- goffset = (c->modrm >> 3) & 7;
-
- if ((c->modrm >> 6) == 3)
- opcode = g_mod3[goffset];
- else
- opcode = g_mod012[goffset];
-
- if (opcode.flags & RMExt) {
+ while (c->d & GroupMask) {
+ switch (c->d & GroupMask) {
+ case Group:
+ c->modrm = insn_fetch(u8, 1, c->eip);
+ --c->eip;
+ goffset = (c->modrm >> 3) & 7;
+ opcode = opcode.u.group[goffset];
+ break;
+ case GroupDual:
+ c->modrm = insn_fetch(u8, 1, c->eip);
+ --c->eip;
+ goffset = (c->modrm >> 3) & 7;
+ if ((c->modrm >> 6) == 3)
+ opcode = opcode.u.gdual->mod3[goffset];
+ else
+ opcode = opcode.u.gdual->mod012[goffset];
+ break;
+ case RMExt:
goffset = c->modrm & 7;
opcode = opcode.u.group[goffset];
- }
-
- c->d |= opcode.flags;
- }
-
- if (c->d & Prefix) {
- if (c->rep_prefix && op_prefix)
+ break;
+ case Prefix:
+ if (c->rep_prefix && op_prefix)
+ return X86EMUL_UNHANDLEABLE;
+ simd_prefix = op_prefix ? 0x66 : c->rep_prefix;
+ switch (simd_prefix) {
+ case 0x00: opcode = opcode.u.gprefix->pfx_no; break;
+ case 0x66: opcode = opcode.u.gprefix->pfx_66; break;
+ case 0xf2: opcode = opcode.u.gprefix->pfx_f2; break;
+ case 0xf3: opcode = opcode.u.gprefix->pfx_f3; break;
+ }
+ break;
+ default:
return X86EMUL_UNHANDLEABLE;
- simd_prefix = op_prefix ? 0x66 : c->rep_prefix;
- switch (simd_prefix) {
- case 0x00: opcode = opcode.u.gprefix->pfx_no; break;
- case 0x66: opcode = opcode.u.gprefix->pfx_66; break;
- case 0xf2: opcode = opcode.u.gprefix->pfx_f2; break;
- case 0xf3: opcode = opcode.u.gprefix->pfx_f3; break;
}
+
+ c->d &= ~GroupMask;
c->d |= opcode.flags;
}
--
1.7.4.3
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