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, // input/output
195 char * modrm_instr, // input
196 int * offset, // output
197 addr_t * first_operand, // output
198 addr_t * second_operand, // output
199 reg_size_t reg_size) { // input
201 struct modrm_byte * modrm = (struct modrm_byte *)modrm_instr;
202 addr_t base_addr = 0;
203 modrm_mode_t mod_mode = 0;
204 operand_type_t addr_type = INVALID_OPERAND;
205 char * instr_cursor = modrm_instr;
207 PrintDebug("ModRM mod=%d\n", modrm->mod);
211 if (modrm->mod == 3) {
213 addr_type = REG_OPERAND;
214 PrintDebug("first operand = Register (RM=%d)\n",modrm->rm);
216 *first_operand = decode_register(gprs, modrm->rm, reg_size);
220 addr_type = MEM_OPERAND;
222 if (modrm->mod == 0) {
224 } else if (modrm->mod == 1) {
226 } else if (modrm->mod == 2) {
232 base_addr = gprs->rbx + gprs->rsi;
235 base_addr = gprs->rbx + gprs->rdi;
238 base_addr = gprs->rbp + gprs->rsi;
241 base_addr = gprs->rbp + gprs->rdi;
244 base_addr = gprs->rsi;
247 base_addr = gprs->rdi;
250 if (modrm->mod == 0) {
254 base_addr = gprs->rbp;
258 base_addr = gprs->rbx;
264 if (mod_mode == DISP8) {
265 base_addr += (uchar_t)*(instr_cursor);
267 } else if (mod_mode == DISP16) {
268 base_addr += (ushort_t)*(instr_cursor);
272 *first_operand = base_addr;
275 *offset += (instr_cursor - modrm_instr);
276 *second_operand = decode_register(gprs, modrm->reg, reg_size);
283 static inline operand_type_t decode_operands32(struct guest_gprs * gprs, // input/output
284 char * modrm_instr, // input
285 int * offset, // output
286 addr_t * first_operand, // output
287 addr_t * second_operand, // output
288 reg_size_t reg_size) { // input
290 char * instr_cursor = modrm_instr;
291 struct modrm_byte * modrm = (struct modrm_byte *)modrm_instr;
292 addr_t base_addr = 0;
293 modrm_mode_t mod_mode = 0;
294 uint_t has_sib_byte = 0;
295 operand_type_t addr_type = INVALID_OPERAND;
301 if (modrm->mod == 3) {
303 addr_type = REG_OPERAND;
305 PrintDebug("first operand = Register (RM=%d)\n",modrm->rm);
307 *first_operand = decode_register(gprs, modrm->rm, reg_size);
311 addr_type = MEM_OPERAND;
313 if (modrm->mod == 0) {
315 } else if (modrm->mod == 1) {
317 } else if (modrm->mod == 2) {
323 base_addr = gprs->rax;
326 base_addr = gprs->rcx;
329 base_addr = gprs->rdx;
332 base_addr = gprs->rbx;
338 if (modrm->mod == 0) {
342 base_addr = gprs->rbp;
346 base_addr = gprs->rsi;
349 base_addr = gprs->rdi;
355 struct sib_byte * sib = (struct sib_byte *)(instr_cursor);
361 if (sib->scale == 1) {
363 } else if (sib->scale == 2) {
365 } else if (sib->scale == 3) {
370 switch (sib->index) {
372 base_addr = gprs->rax;
375 base_addr = gprs->rcx;
378 base_addr = gprs->rdx;
381 base_addr = gprs->rbx;
387 base_addr = gprs->rbp;
390 base_addr = gprs->rsi;
393 base_addr = gprs->rdi;
402 base_addr += gprs->rax;
405 base_addr += gprs->rcx;
408 base_addr += gprs->rdx;
411 base_addr += gprs->rbx;
414 base_addr += gprs->rsp;
417 if (modrm->mod != 0) {
418 base_addr += gprs->rbp;
422 base_addr += gprs->rsi;
425 base_addr += gprs->rdi;
432 if (mod_mode == DISP8) {
433 base_addr += (uchar_t)*(instr_cursor);
435 } else if (mod_mode == DISP32) {
436 base_addr += (uint_t)*(instr_cursor);
441 *first_operand = base_addr;
444 *offset += (instr_cursor - modrm_instr);
446 *second_operand = decode_register(gprs, modrm->reg, reg_size);