Instead of having a group number, store the group table pointer directly in
the opcode.
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
---
arch/x86/kvm/emulate.c | 47 ++++++++++++++++++++++++++++++++++++++---------
1 files changed, 38 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index b0100f6..ee5b38d 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -110,10 +110,21 @@ enum {
struct opcode {
u32 flags;
+ union {
+ struct opcode *group;
+ struct group_dual *gdual;
+ } u;
+};
+
+struct group_dual {
+ struct opcode mod012[8];
+ struct opcode mod3[8];
};
#define D(_y) { .flags = (_y) }
#define N D(0)
+#define G(_f, _g) { .flags = ((_f) | Group), .u.group = (_g) }
+#define GD(_f, _g) { .flags = ((_f) | Group | GroupDual), .u.gdual = (_g) }
static struct opcode group_table[] = {
[Group1*8] =
@@ -331,6 +342,8 @@ static struct opcode twobyte_table[256] = {
#undef D
#undef N
+#undef G
+#undef GD
/* EFLAGS bit definitions. */
#define EFLG_ID (1<<21)
@@ -927,8 +940,8 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
struct decode_cache *c = &ctxt->decode;
int rc = X86EMUL_CONTINUE;
int mode = ctxt->mode;
- int def_op_bytes, def_ad_bytes, group, dual;
-
+ int def_op_bytes, def_ad_bytes, group, dual, goffset;
+ struct opcode opcode, *g_mod012, *g_mod3;
/* we cannot decode insn before we complete previous rep insn */
WARN_ON(ctxt->restart);
@@ -1015,15 +1028,16 @@ done_prefixes:
c->op_bytes = 8; /* REX.W */
/* Opcode byte(s). */
- c->d = opcode_table[c->b].flags;
- if (c->d == 0) {
+ opcode = opcode_table[c->b];
+ if (opcode.flags == 0) {
/* Two-byte opcode? */
if (c->b == 0x0f) {
c->twobyte = 1;
c->b = insn_fetch(u8, 1, c->eip);
- c->d = twobyte_table[c->b].flags;
+ opcode = twobyte_table[c->b];
}
}
+ c->d = opcode.flags;
if (c->d & Group) {
group = c->d & GroupMask;
@@ -1031,12 +1045,27 @@ done_prefixes:
c->modrm = insn_fetch(u8, 1, c->eip);
--c->eip;
- group = (group << 3) + ((c->modrm >> 3) & 7);
+ if (group) {
+ g_mod012 = g_mod3 = &group_table[group * 8];
+ if (c->d & GroupDual)
+ g_mod3 = &group2_table[group * 8];
+ } else {
+ 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 | GroupMask);
- if (dual && (c->modrm >> 6) == 3)
- c->d |= group2_table[group].flags;
+
+ goffset = (c->modrm >> 3) & 7;
+
+ if ((c->modrm >> 6) == 3)
+ opcode = g_mod3[goffset];
else
- c->d |= group_table[group].flags;
+ opcode = g_mod012[goffset];
+ c->d |= opcode.flags;
}
/* Unrecognised? */
--
1.7.1
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