1 #ifndef __VMM_EMULATE_H
2 #define __VMM_EMULATE_H
3 #include <geekos/vm_guest.h>
7 * This is where we do the hideous X86 instruction parsing among other things
8 * We can parse out the instruction prefixes, as well as decode the operands
10 * Before we begin I'd just like to say a few words to those that made this possible...
41 /* JRL: Some of this was taken from the Xen sources...
45 #define PACKED __attribute__((packed))
47 #define MODRM_MOD(x) ((x >> 6) & 0x3)
48 #define MODRM_REG(x) ((x >> 3) & 0x7)
49 #define MODRM_RM(x) (x & 0x7)
53 uint_t reg : 3 PACKED;
54 uint_t mod : 2 PACKED;
58 #define SIB_BASE(x) ((x >> 6) & 0x3)
59 #define SIB_INDEX(x) ((x >> 3) & 0x7)
60 #define SIB_SCALE(x) (x & 0x7)
63 uint_t base : 3 PACKED;
64 uint_t index : 3 PACKED;
65 uint_t scale : 2 PACKED;
70 #define MAKE_INSTR(nm, ...) static const uchar_t OPCODE_##nm[] = { __VA_ARGS__ }
73 * Here's how it works:
75 * Following bytes: Opcode bytes.
76 * Special case: Last byte, if zero, doesn't need to match.
78 MAKE_INSTR(INVD, 2, 0x0f, 0x08);
79 MAKE_INSTR(CPUID, 2, 0x0f, 0xa2);
80 MAKE_INSTR(RDMSR, 2, 0x0f, 0x32);
81 MAKE_INSTR(WRMSR, 2, 0x0f, 0x30);
82 MAKE_INSTR(RDTSC, 2, 0x0f, 0x31);
83 MAKE_INSTR(RDTSCP, 3, 0x0f, 0x01, 0xf9);
84 MAKE_INSTR(CLI, 1, 0xfa);
85 MAKE_INSTR(STI, 1, 0xfb);
86 MAKE_INSTR(RDPMC, 2, 0x0f, 0x33);
87 MAKE_INSTR(CLGI, 3, 0x0f, 0x01, 0xdd);
88 MAKE_INSTR(STGI, 3, 0x0f, 0x01, 0xdc);
89 MAKE_INSTR(VMRUN, 3, 0x0f, 0x01, 0xd8);
90 MAKE_INSTR(VMLOAD, 3, 0x0f, 0x01, 0xda);
91 MAKE_INSTR(VMSAVE, 3, 0x0f, 0x01, 0xdb);
92 MAKE_INSTR(VMCALL, 3, 0x0f, 0x01, 0xd9);
93 MAKE_INSTR(PAUSE, 2, 0xf3, 0x90);
94 MAKE_INSTR(SKINIT, 3, 0x0f, 0x01, 0xde);
95 MAKE_INSTR(MOV2CR, 3, 0x0f, 0x22, 0x00);
96 MAKE_INSTR(MOVCR2, 3, 0x0f, 0x20, 0x00);
97 MAKE_INSTR(MOV2DR, 3, 0x0f, 0x23, 0x00);
98 MAKE_INSTR(MOVDR2, 3, 0x0f, 0x21, 0x00);
99 MAKE_INSTR(PUSHF, 1, 0x9c);
100 MAKE_INSTR(POPF, 1, 0x9d);
101 MAKE_INSTR(RSM, 2, 0x0f, 0xaa);
102 MAKE_INSTR(INVLPG, 3, 0x0f, 0x01, 0x00);
103 MAKE_INSTR(INVLPGA,3, 0x0f, 0x01, 0xdf);
104 MAKE_INSTR(HLT, 1, 0xf4);
105 MAKE_INSTR(CLTS, 2, 0x0f, 0x06);
106 MAKE_INSTR(LMSW, 3, 0x0f, 0x01, 0x00);
107 MAKE_INSTR(SMSW, 3, 0x0f, 0x01, 0x00);
110 static const uchar_t PREFIX_LOCK = 0xF0;
111 static const uchar_t PREFIX_REPNE = 0xF2;
112 static const uchar_t PREFIX_REPNZ = 0xF2;
113 static const uchar_t PREFIX_REP = 0xF3;
114 static const uchar_t PREFIX_REPE = 0xF3;
115 static const uchar_t PREFIX_REPZ = 0xF3;
116 static const uchar_t PREFIX_CS_OVERRIDE = 0x2E;
117 static const uchar_t PREFIX_SS_OVERRIDE = 0x36;
118 static const uchar_t PREFIX_DS_OVERRIDE = 0x3E;
119 static const uchar_t PREFIX_ES_OVERRIDE = 0x26;
120 static const uchar_t PREFIX_FS_OVERRIDE = 0x64;
121 static const uchar_t PREFIX_GS_OVERRIDE = 0x65;
122 static const uchar_t PREFIX_BR_NOT_TAKEN = 0x2E;
123 static const uchar_t PREFIX_BR_TAKEN = 0x3E;
124 static const uchar_t PREFIX_OP_SIZE = 0x66;
125 static const uchar_t PREFIX_ADDR_SIZE = 0x67;
128 static inline int is_prefix_byte(char byte) {
131 case 0xF2: // REPNE/REPNZ
132 case 0xF3: // REP or REPE/REPZ
133 case 0x2E: // CS override or Branch hint not taken (with Jcc instrs)
134 case 0x36: // SS override
135 case 0x3E: // DS override or Branch hint taken (with Jcc instrs)
136 case 0x26: // ES override
137 case 0x64: // FS override
138 case 0x65: // GS override
139 //case 0x2E: // branch not taken hint
140 // case 0x3E: // branch taken hint
141 case 0x66: // operand size override
142 case 0x67: // address size override
153 typedef enum {INVALID_ADDR_TYPE, REG, DISP0, DISP8, DISP16, DISP32} modrm_mode_t;
154 typedef enum {INVALID_REG_SIZE, REG64, REG32, REG16, REG8} reg_size_t;
155 typedef enum {INVALID_OPERAND, REG_OPERAND, MEM_OPERAND} operand_type_t;
159 static inline addr_t decode_register(struct guest_gprs * gprs, char reg_code, reg_size_t reg_size) {
164 reg_addr = (addr_t)&(gprs->rax);
167 reg_addr = (addr_t)&(gprs->rcx);
170 reg_addr = (addr_t)&(gprs->rdx);
173 reg_addr = (addr_t)&(gprs->rbx);
176 if (reg_size == REG8) {
177 reg_addr = (addr_t)&(gprs->rax) + 1;
179 reg_addr = (addr_t)&(gprs->rsp);
183 if (reg_size == REG8) {
184 reg_addr = (addr_t)&(gprs->rcx) + 1;
186 reg_addr = (addr_t)&(gprs->rbp);
190 if (reg_size == REG8) {
191 reg_addr = (addr_t)&(gprs->rdx) + 1;
193 reg_addr = (addr_t)&(gprs->rsi);
197 if (reg_size == REG8) {
198 reg_addr = (addr_t)&(gprs->rbx) + 1;
200 reg_addr = (addr_t)&(gprs->rdi);
213 static inline operand_type_t decode_operands16(struct guest_gprs * gprs, // input/output
214 char * modrm_instr, // input
215 int * offset, // output
216 addr_t * first_operand, // output
217 addr_t * second_operand, // output
218 reg_size_t reg_size) { // input
220 struct modrm_byte * modrm = (struct modrm_byte *)modrm_instr;
221 addr_t base_addr = 0;
222 modrm_mode_t mod_mode = 0;
223 operand_type_t addr_type = INVALID_OPERAND;
224 char * instr_cursor = modrm_instr;
226 PrintDebug("ModRM mod=%d\n", modrm->mod);
230 if (modrm->mod == 3) {
232 addr_type = REG_OPERAND;
233 PrintDebug("first operand = Register (RM=%d)\n",modrm->rm);
235 *first_operand = decode_register(gprs, modrm->rm, reg_size);
239 addr_type = MEM_OPERAND;
241 if (modrm->mod == 0) {
243 } else if (modrm->mod == 1) {
245 } else if (modrm->mod == 2) {
251 base_addr = gprs->rbx + gprs->rsi;
254 base_addr = gprs->rbx + gprs->rdi;
257 base_addr = gprs->rbp + gprs->rsi;
260 base_addr = gprs->rbp + gprs->rdi;
263 base_addr = gprs->rsi;
266 base_addr = gprs->rdi;
269 if (modrm->mod == 0) {
273 base_addr = gprs->rbp;
277 base_addr = gprs->rbx;
283 if (mod_mode == DISP8) {
284 base_addr += (uchar_t)*(instr_cursor);
286 } else if (mod_mode == DISP16) {
287 base_addr += (ushort_t)*(instr_cursor);
291 *first_operand = base_addr;
294 *offset += (instr_cursor - modrm_instr);
295 *second_operand = decode_register(gprs, modrm->reg, reg_size);
302 static inline operand_type_t decode_operands32(struct guest_gprs * gprs, // input/output
303 char * modrm_instr, // input
304 int * offset, // output
305 addr_t * first_operand, // output
306 addr_t * second_operand, // output
307 reg_size_t reg_size) { // input
309 char * instr_cursor = modrm_instr;
310 struct modrm_byte * modrm = (struct modrm_byte *)modrm_instr;
311 addr_t base_addr = 0;
312 modrm_mode_t mod_mode = 0;
313 uint_t has_sib_byte = 0;
314 operand_type_t addr_type = INVALID_OPERAND;
320 if (modrm->mod == 3) {
322 addr_type = REG_OPERAND;
324 PrintDebug("first operand = Register (RM=%d)\n",modrm->rm);
326 *first_operand = decode_register(gprs, modrm->rm, reg_size);
330 addr_type = MEM_OPERAND;
332 if (modrm->mod == 0) {
334 } else if (modrm->mod == 1) {
336 } else if (modrm->mod == 2) {
342 base_addr = gprs->rax;
345 base_addr = gprs->rcx;
348 base_addr = gprs->rdx;
351 base_addr = gprs->rbx;
357 if (modrm->mod == 0) {
361 base_addr = gprs->rbp;
365 base_addr = gprs->rsi;
368 base_addr = gprs->rdi;
374 struct sib_byte * sib = (struct sib_byte *)(instr_cursor);
380 if (sib->scale == 1) {
382 } else if (sib->scale == 2) {
384 } else if (sib->scale == 3) {
389 switch (sib->index) {
391 base_addr = gprs->rax;
394 base_addr = gprs->rcx;
397 base_addr = gprs->rdx;
400 base_addr = gprs->rbx;
406 base_addr = gprs->rbp;
409 base_addr = gprs->rsi;
412 base_addr = gprs->rdi;
421 base_addr += gprs->rax;
424 base_addr += gprs->rcx;
427 base_addr += gprs->rdx;
430 base_addr += gprs->rbx;
433 base_addr += gprs->rsp;
436 if (modrm->mod != 0) {
437 base_addr += gprs->rbp;
441 base_addr += gprs->rsi;
444 base_addr += gprs->rdi;
451 if (mod_mode == DISP8) {
452 base_addr += (uchar_t)*(instr_cursor);
454 } else if (mod_mode == DISP32) {
455 base_addr += (uint_t)*(instr_cursor);
460 *first_operand = base_addr;
463 *offset += (instr_cursor - modrm_instr);
465 *second_operand = decode_register(gprs, modrm->reg, reg_size);