redonkable/alistair23-linux
redonkable/alistair23-linux
1
0
Fork 0
Code Releases Activity

KVM: x86 emulator: mix decode bits from opcode and group decode tables

Browse source 
Allow bits that are common to all members of a group to be specified in the
opcode table instead of the group table.  This allows some simplification
of the decode tables.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This commit is contained in:
Avi Kivity 2010-07-26 14:37:48 +03:00
parent 047a481809
commit 52811d7de5
1 changed files with 6 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
arch/x86/kvm/emulate.c
View file

@ -955,7 +955,7 @@ 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;
int def_op_bytes, def_ad_bytes, group, dual;
/* we cannot decode insn before we complete previous rep insn */
@ -1055,14 +1055,16 @@ done_prefixes:
if (c->d & Group) {
group = c->d & GroupMask;
dual = c->d & GroupDual;
c->modrm = insn_fetch(u8, 1, c->eip);
--c->eip;
group = (group << 3) + ((c->modrm >> 3) & 7);
if ((c->d & GroupDual) && (c->modrm >> 6) == 3)
c->d = group2_table[group];
c->d &= ~(Group | GroupDual | GroupMask);
if (dual && (c->modrm >> 6) == 3)
c->d |= group2_table[group];
else
c->d = group_table[group];
c->d |= group_table[group];
}
/* Unrecognised? */