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);
111 static inline int is_prefix_byte(char byte) {
114 case 0xF2: // REPNE/REPNZ
115 case 0xF3: // REP or REPE/REPZ
116 case 0x2E: // CS override or Branch hint not taken (with Jcc instrs)
117 case 0x36: // SS override
118 case 0x3E: // DS override or Branch hint taken (with Jcc instrs)
119 case 0x26: // ES override
120 case 0x64: // FS override
121 case 0x65: // GS override
122 //case 0x2E: // branch not taken hint
123 // case 0x3E: // branch taken hint
124 case 0x66: // operand size override
125 case 0x67: // address size override
134 typedef enum {INVALID_ADDR_TYPE, REG, DISP0, DISP8, DISP16, DISP32} modrm_mode_t;
135 typedef enum {INVALID_REG_SIZE, REG64, REG32, REG16, REG8} reg_size_t;
136 typedef enum {INVALID_OPERAND, REG_OPERAND, MEM_OPERAND} operand_type_t;
140 static inline addr_t decode_register(struct guest_gprs * gprs, char reg_code, reg_size_t reg_size) {
145 reg_addr = (addr_t)&(gprs->rax);
148 reg_addr = (addr_t)&(gprs->rcx);
151 reg_addr = (addr_t)&(gprs->rdx);
154 reg_addr = (addr_t)&(gprs->rbx);
157 if (reg_size == REG8) {
158 reg_addr = (addr_t)&(gprs->rax) + 1;
160 reg_addr = (addr_t)&(gprs->rsp);
164 if (reg_size == REG8) {
165 reg_addr = (addr_t)&(gprs->rcx) + 1;
167 reg_addr = (addr_t)&(gprs->rbp);
171 if (reg_size == REG8) {
172 reg_addr = (addr_t)&(gprs->rdx) + 1;
174 reg_addr = (addr_t)&(gprs->rsi);
178 if (reg_size == REG8) {
179 reg_addr = (addr_t)&(gprs->rbx) + 1;
181 reg_addr = (addr_t)&(gprs->rdi);
194 static inline operand_type_t decode_operands16(struct guest_gprs * gprs,
196 addr_t * first_operand,
197 addr_t * second_operand,
198 reg_size_t reg_size) {
200 struct modrm_byte * modrm = (struct modrm_byte *)modrm_instr;
201 addr_t base_addr = 0;
202 modrm_mode_t mod_mode = 0;
203 operand_type_t addr_type = INVALID_OPERAND;
205 PrintDebug("ModRM mod=%d\n", modrm->mod);
207 if (modrm->mod == 3) {
209 addr_type = REG_OPERAND;
210 PrintDebug("first operand = Register (RM=%d)\n",modrm->rm);
212 *first_operand = decode_register(gprs, modrm->rm, reg_size);
216 addr_type = MEM_OPERAND;
218 if (modrm->mod == 0) {
220 } else if (modrm->mod == 1) {
222 } else if (modrm->mod == 2) {
228 base_addr = gprs->rbx + gprs->rsi;
231 base_addr = gprs->rbx + gprs->rdi;
234 base_addr = gprs->rbp + gprs->rsi;
237 base_addr = gprs->rbp + gprs->rdi;
240 base_addr = gprs->rsi;
243 base_addr = gprs->rdi;
246 if (modrm->mod == 0) {
250 base_addr = gprs->rbp;
254 base_addr = gprs->rbx;
258 if (mod_mode == DISP8) {
259 base_addr += (uchar_t)*(modrm_instr + 1);
260 } else if (mod_mode == DISP16) {
261 base_addr += (ushort_t)*(modrm_instr + 1);
264 *first_operand = base_addr;
267 *second_operand = decode_register(gprs, modrm->reg, reg_size);
274 static inline operand_type_t decode_operands32(struct guest_gprs * gprs,
276 addr_t * first_operand,
277 addr_t * second_operand,
278 reg_size_t reg_size) {
280 char * instr_cursor = modrm_instr;
281 struct modrm_byte * modrm = (struct modrm_byte *)modrm_instr;
282 addr_t base_addr = 0;
283 modrm_mode_t mod_mode = 0;
284 uint_t has_sib_byte = 0;
285 operand_type_t addr_type = INVALID_OPERAND;
287 if (modrm->mod == 3) {
289 addr_type = REG_OPERAND;
291 PrintDebug("first operand = Register (RM=%d)\n",modrm->rm);
293 *first_operand = decode_register(gprs, modrm->rm, reg_size);
297 addr_type = MEM_OPERAND;
299 if (modrm->mod == 0) {
301 } else if (modrm->mod == 1) {
303 } else if (modrm->mod == 2) {
309 base_addr = gprs->rax;
312 base_addr = gprs->rcx;
315 base_addr = gprs->rdx;
318 base_addr = gprs->rbx;
324 if (modrm->mod == 0) {
328 base_addr = gprs->rbp;
332 base_addr = gprs->rsi;
335 base_addr = gprs->rdi;
341 struct sib_byte * sib = (struct sib_byte *)(instr_cursor);
345 if (sib->scale == 1) {
347 } else if (sib->scale == 2) {
349 } else if (sib->scale == 3) {
354 switch (sib->index) {
356 base_addr = gprs->rax;
359 base_addr = gprs->rcx;
362 base_addr = gprs->rdx;
365 base_addr = gprs->rbx;
371 base_addr = gprs->rbp;
374 base_addr = gprs->rsi;
377 base_addr = gprs->rdi;
386 base_addr += gprs->rax;
389 base_addr += gprs->rcx;
392 base_addr += gprs->rdx;
395 base_addr += gprs->rbx;
398 base_addr += gprs->rsp;
401 if (modrm->mod != 0) {
402 base_addr += gprs->rbp;
406 base_addr += gprs->rsi;
409 base_addr += gprs->rdi;
417 if (mod_mode == DISP8) {
418 base_addr += (uchar_t)*(instr_cursor);
419 } else if (mod_mode == DISP32) {
420 base_addr += (uint_t)*(instr_cursor);
424 *first_operand = base_addr;
427 *second_operand = decode_register(gprs, modrm->reg, reg_size);