Commit 52811d7d authored by Avi Kivity's avatar Avi Kivity
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KVM: x86 emulator: mix decode bits from opcode and group decode tables 



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: default avatarAvi Kivity <avi@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 047a4818

arch/x86/kvm/emulate.c

+6 −4
Original line number Diff line number Diff line
@@ -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 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 


	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? */