Commit 46561646 authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: x86 emulator: consolidate group handling 



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: default avatarAvi Kivity <avi@redhat.com>
parent 781e0743

arch/x86/kvm/emulate.c

+40 −40
Original line number Diff line number Diff line
@@ -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;
@@ -3433,35 +3434,28 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) 
	}

	c->d = opcode.flags;



	if (c->d & Group) {

		dual = c->d & GroupDual;

	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;



		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];

				opcode = opcode.u.gdual->mod3[goffset];

			else

			opcode = g_mod012[goffset];



		if (opcode.flags & RMExt) {

				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) {

			break;

		case Prefix:

			if (c->rep_prefix && op_prefix)

				return X86EMUL_UNHANDLEABLE;

			simd_prefix = op_prefix ? 0x66 : c->rep_prefix;
@@ -3471,6 +3465,12 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) 
			case 0xf2: opcode = opcode.u.gprefix->pfx_f2; break;

			case 0xf3: opcode = opcode.u.gprefix->pfx_f3; break;

			}

			break;

		default:

			return X86EMUL_UNHANDLEABLE;

		}



		c->d &= ~GroupMask;

		c->d |= opcode.flags;

	}