xref: /openbmc/qemu/target/i386/tcg/decode-new.h (revision dbea1c89)
1 /*
2  * Decode table flags, mostly based on Intel SDM.
3  *
4  *  Copyright (c) 2022 Red Hat, Inc.
5  *
6  * Author: Paolo Bonzini <pbonzini@redhat.com>
7  *
8  * This library is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * This library is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
20  */
21 
22 typedef enum X86OpType {
23     X86_TYPE_None,
24 
25     X86_TYPE_A, /* Implicit */
26     X86_TYPE_B, /* VEX.vvvv selects a GPR */
27     X86_TYPE_C, /* REG in the modrm byte selects a control register */
28     X86_TYPE_D, /* REG in the modrm byte selects a debug register */
29     X86_TYPE_E, /* ALU modrm operand */
30     X86_TYPE_F, /* EFLAGS/RFLAGS */
31     X86_TYPE_G, /* REG in the modrm byte selects a GPR */
32     X86_TYPE_H, /* For AVX, VEX.vvvv selects an XMM/YMM register */
33     X86_TYPE_I, /* Immediate */
34     X86_TYPE_J, /* Relative offset for a jump */
35     X86_TYPE_L, /* The upper 4 bits of the immediate select a 128-bit register */
36     X86_TYPE_M, /* modrm byte selects a memory operand */
37     X86_TYPE_N, /* R/M in the modrm byte selects an MMX register */
38     X86_TYPE_O, /* Absolute address encoded in the instruction */
39     X86_TYPE_P, /* reg in the modrm byte selects an MMX register */
40     X86_TYPE_Q, /* MMX modrm operand */
41     X86_TYPE_R, /* R/M in the modrm byte selects a register */
42     X86_TYPE_S, /* reg selects a segment register */
43     X86_TYPE_U, /* R/M in the modrm byte selects an XMM/YMM register */
44     X86_TYPE_V, /* reg in the modrm byte selects an XMM/YMM register */
45     X86_TYPE_W, /* XMM/YMM modrm operand */
46     X86_TYPE_X, /* string source */
47     X86_TYPE_Y, /* string destination */
48 
49     /* Custom */
50     X86_TYPE_EM, /* modrm byte selects an ALU memory operand */
51     X86_TYPE_WM, /* modrm byte selects an XMM/YMM memory operand */
52     X86_TYPE_I_unsigned, /* Immediate, zero-extended */
53     X86_TYPE_2op, /* 2-operand RMW instruction */
54     X86_TYPE_LoBits, /* encoded in bits 0-2 of the operand + REX.B */
55     X86_TYPE_0, /* Hard-coded GPRs (RAX..RDI) */
56     X86_TYPE_1,
57     X86_TYPE_2,
58     X86_TYPE_3,
59     X86_TYPE_4,
60     X86_TYPE_5,
61     X86_TYPE_6,
62     X86_TYPE_7,
63     X86_TYPE_ES, /* Hard-coded segment registers */
64     X86_TYPE_CS,
65     X86_TYPE_SS,
66     X86_TYPE_DS,
67     X86_TYPE_FS,
68     X86_TYPE_GS,
69 } X86OpType;
70 
71 typedef enum X86OpSize {
72     X86_SIZE_None,
73 
74     X86_SIZE_a,  /* BOUND operand */
75     X86_SIZE_b,  /* byte */
76     X86_SIZE_d,  /* 32-bit */
77     X86_SIZE_dq, /* SSE/AVX 128-bit */
78     X86_SIZE_p,  /* Far pointer */
79     X86_SIZE_pd, /* SSE/AVX packed double precision */
80     X86_SIZE_pi, /* MMX */
81     X86_SIZE_ps, /* SSE/AVX packed single precision */
82     X86_SIZE_q,  /* 64-bit */
83     X86_SIZE_qq, /* AVX 256-bit */
84     X86_SIZE_s,  /* Descriptor */
85     X86_SIZE_sd, /* SSE/AVX scalar double precision */
86     X86_SIZE_ss, /* SSE/AVX scalar single precision */
87     X86_SIZE_si, /* 32-bit GPR */
88     X86_SIZE_v,  /* 16/32/64-bit, based on operand size */
89     X86_SIZE_w,  /* 16-bit */
90     X86_SIZE_x,  /* 128/256-bit, based on operand size */
91     X86_SIZE_y,  /* 32/64-bit, based on operand size */
92     X86_SIZE_z,  /* 16-bit for 16-bit operand size, else 32-bit */
93     X86_SIZE_z_f64,  /* 32-bit for 32-bit operand size or 64-bit mode, else 16-bit */
94 
95     /* Custom */
96     X86_SIZE_d64,
97     X86_SIZE_f64,
98     X86_SIZE_xh, /* SSE/AVX packed half register */
99 } X86OpSize;
100 
101 typedef enum X86CPUIDFeature {
102     X86_FEAT_None,
103     X86_FEAT_3DNOW,
104     X86_FEAT_ADX,
105     X86_FEAT_AES,
106     X86_FEAT_AVX,
107     X86_FEAT_AVX2,
108     X86_FEAT_BMI1,
109     X86_FEAT_BMI2,
110     X86_FEAT_CMOV,
111     X86_FEAT_CMPCCXADD,
112     X86_FEAT_F16C,
113     X86_FEAT_FMA,
114     X86_FEAT_MOVBE,
115     X86_FEAT_PCLMULQDQ,
116     X86_FEAT_SHA_NI,
117     X86_FEAT_SSE,
118     X86_FEAT_SSE2,
119     X86_FEAT_SSE3,
120     X86_FEAT_SSSE3,
121     X86_FEAT_SSE41,
122     X86_FEAT_SSE42,
123     X86_FEAT_SSE4A,
124 } X86CPUIDFeature;
125 
126 /* Execution flags */
127 
128 typedef enum X86OpUnit {
129     X86_OP_SKIP,    /* not valid or managed by emission function */
130     X86_OP_SEG,     /* segment selector */
131     X86_OP_CR,      /* control register */
132     X86_OP_DR,      /* debug register */
133     X86_OP_INT,     /* loaded into/stored from s->T0/T1 */
134     X86_OP_IMM,     /* immediate */
135     X86_OP_SSE,     /* address in either s->ptrX or s->A0 depending on has_ea */
136     X86_OP_MMX,     /* address in either s->ptrX or s->A0 depending on has_ea */
137 } X86OpUnit;
138 
139 typedef enum X86InsnCheck {
140     /* Illegal or exclusive to 64-bit mode */
141     X86_CHECK_i64 = 1,
142     X86_CHECK_o64 = 2,
143 
144     /* Fault outside protected mode */
145     X86_CHECK_prot = 4,
146 
147     /* Privileged instruction checks */
148     X86_CHECK_cpl0 = 8,
149     X86_CHECK_vm86_iopl = 16,
150     X86_CHECK_cpl_iopl = 32,
151     X86_CHECK_iopl = X86_CHECK_cpl_iopl | X86_CHECK_vm86_iopl,
152 
153     /* Fault if VEX.L=1 */
154     X86_CHECK_VEX128 = 64,
155 
156     /* Fault if VEX.W=1 */
157     X86_CHECK_W0 = 128,
158 
159     /* Fault if VEX.W=0 */
160     X86_CHECK_W1 = 256,
161 } X86InsnCheck;
162 
163 typedef enum X86InsnSpecial {
164     X86_SPECIAL_None,
165 
166     /* Accepts LOCK prefix; LOCKed operations do not load or writeback operand 0 */
167     X86_SPECIAL_HasLock,
168 
169     /* Always locked if it has a memory operand (XCHG) */
170     X86_SPECIAL_Locked,
171 
172     /* Do not apply segment base to effective address */
173     X86_SPECIAL_NoSeg,
174     /*
175      * Rd/Mb or Rd/Mw in the manual: register operand 0 is treated as 32 bits
176      * (and writeback zero-extends it to 64 bits if applicable).  PREFIX_DATA
177      * does not trigger 16-bit writeback and, as a side effect, high-byte
178      * registers are never used.
179      */
180     X86_SPECIAL_Op0_Rd,
181 
182     /*
183      * Ry/Mb in the manual (PINSRB).  However, the high bits are never used by
184      * the instruction in either the register or memory cases; the *real* effect
185      * of this modifier is that high-byte registers are never used, even without
186      * a REX prefix.  Therefore, PINSRW does not need it despite having Ry/Mw.
187      */
188     X86_SPECIAL_Op2_Ry,
189 
190     /*
191      * Register operand 2 is extended to full width, while a memory operand
192      * is doubled in size if VEX.L=1.
193      */
194     X86_SPECIAL_AVXExtMov,
195 
196     /*
197      * MMX instruction exists with no prefix; if there is no prefix, V/H/W/U operands
198      * become P/P/Q/N, and size "x" becomes "q".
199      */
200     X86_SPECIAL_MMX,
201 
202     /* When loaded into s->T0, register operand 1 is zero/sign extended.  */
203     X86_SPECIAL_SExtT0,
204     X86_SPECIAL_ZExtT0,
205 } X86InsnSpecial;
206 
207 /*
208  * Special cases for instructions that operate on XMM/YMM registers.  Intel
209  * retconned all of them to have VEX exception classes other than 0 and 13, so
210  * all these only matter for instructions that have a VEX exception class.
211  * Based on tables in the "AVX and SSE Instruction Exception Specification"
212  * section of the manual.
213  */
214 typedef enum X86VEXSpecial {
215     /* Legacy SSE instructions that allow unaligned operands */
216     X86_VEX_SSEUnaligned,
217 
218     /*
219      * Used for instructions that distinguish the XMM operand type with an
220      * instruction prefix; legacy SSE encodings will allow unaligned operands
221      * for scalar operands only (identified by a REP prefix).  In this case,
222      * the decoding table uses "x" for the vector operands instead of specifying
223      * pd/ps/sd/ss individually.
224      */
225     X86_VEX_REPScalar,
226 
227     /*
228      * VEX instructions that only support 256-bit operands with AVX2 (Table 2-17
229      * column 3).  Columns 2 and 4 (instructions limited to 256- and 127-bit
230      * operands respectively) are implicit in the presence of dq and qq
231      * operands, and thus handled by decode_op_size.
232      */
233     X86_VEX_AVX2_256,
234 } X86VEXSpecial;
235 
236 
237 typedef struct X86OpEntry  X86OpEntry;
238 typedef struct X86DecodedInsn X86DecodedInsn;
239 
240 /* Decode function for multibyte opcodes.  */
241 typedef void (*X86DecodeFunc)(DisasContext *s, CPUX86State *env, X86OpEntry *entry, uint8_t *b);
242 
243 /* Code generation function.  */
244 typedef void (*X86GenFunc)(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode);
245 
246 struct X86OpEntry {
247     /* Based on the is_decode flags.  */
248     union {
249         X86GenFunc gen;
250         X86DecodeFunc decode;
251     };
252     /* op0 is always written, op1 and op2 are always read.  */
253     X86OpType    op0:8;
254     X86OpSize    s0:8;
255     X86OpType    op1:8;
256     X86OpSize    s1:8;
257     X86OpType    op2:8;
258     X86OpSize    s2:8;
259     /* Must be I and b respectively if present.  */
260     X86OpType    op3:8;
261     X86OpSize    s3:8;
262 
263     X86InsnSpecial special:8;
264     X86CPUIDFeature cpuid:8;
265     unsigned     vex_class:8;
266     X86VEXSpecial vex_special:8;
267     unsigned     valid_prefix:16;
268     unsigned     check:16;
269     unsigned     intercept:8;
270     bool         is_decode:1;
271 };
272 
273 typedef struct X86DecodedOp {
274     int8_t n;
275     MemOp ot;     /* For b/c/d/p/s/q/v/w/y/z */
276     X86OpUnit unit;
277     bool has_ea;
278     int offset;   /* For MMX and SSE */
279 
280     union {
281 	target_ulong imm;
282         /*
283          * This field is used internally by macros OP0_PTR/OP1_PTR/OP2_PTR,
284          * do not access directly!
285          */
286         TCGv_ptr v_ptr;
287     };
288 } X86DecodedOp;
289 
290 struct X86DecodedInsn {
291     X86OpEntry e;
292     X86DecodedOp op[3];
293     /*
294      * Rightmost immediate, for convenience since most instructions have
295      * one (and also for 4-operand instructions).
296      */
297     target_ulong immediate;
298     AddressParts mem;
299 
300     TCGv cc_dst, cc_src, cc_src2;
301     TCGv_i32 cc_op_dynamic;
302     int8_t cc_op;
303 
304     uint8_t b;
305 };
306 
307