1 #ifndef __VMM_EMULATE_H
2 #define __VMM_EMULATE_H
3 #include <palacios/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
13 /* JRL: Some of this was taken from the Xen sources...
17 #define PACKED __attribute__((packed))
19 #define MODRM_MOD(x) ((x >> 6) & 0x3)
20 #define MODRM_REG(x) ((x >> 3) & 0x7)
21 #define MODRM_RM(x) (x & 0x7)
25 uint_t reg : 3 PACKED;
26 uint_t mod : 2 PACKED;
30 #define SIB_BASE(x) ((x >> 6) & 0x3)
31 #define SIB_INDEX(x) ((x >> 3) & 0x7)
32 #define SIB_SCALE(x) (x & 0x7)
35 uint_t base : 3 PACKED;
36 uint_t index : 3 PACKED;
37 uint_t scale : 2 PACKED;
42 #define MAKE_INSTR(nm, ...) static const uchar_t OPCODE_##nm[] = { __VA_ARGS__ }
45 * Here's how it works:
47 * Following bytes: Opcode bytes.
48 * Special case: Last byte, if zero, doesn't need to match.
50 MAKE_INSTR(INVD, 2, 0x0f, 0x08);
51 MAKE_INSTR(CPUID, 2, 0x0f, 0xa2);
52 MAKE_INSTR(RDMSR, 2, 0x0f, 0x32);
53 MAKE_INSTR(WRMSR, 2, 0x0f, 0x30);
54 MAKE_INSTR(RDTSC, 2, 0x0f, 0x31);
55 MAKE_INSTR(RDTSCP, 3, 0x0f, 0x01, 0xf9);
56 MAKE_INSTR(CLI, 1, 0xfa);
57 MAKE_INSTR(STI, 1, 0xfb);
58 MAKE_INSTR(RDPMC, 2, 0x0f, 0x33);
59 MAKE_INSTR(CLGI, 3, 0x0f, 0x01, 0xdd);
60 MAKE_INSTR(STGI, 3, 0x0f, 0x01, 0xdc);
61 MAKE_INSTR(VMRUN, 3, 0x0f, 0x01, 0xd8);
62 MAKE_INSTR(VMLOAD, 3, 0x0f, 0x01, 0xda);
63 MAKE_INSTR(VMSAVE, 3, 0x0f, 0x01, 0xdb);
64 MAKE_INSTR(VMCALL, 3, 0x0f, 0x01, 0xd9);
65 MAKE_INSTR(PAUSE, 2, 0xf3, 0x90);
66 MAKE_INSTR(SKINIT, 3, 0x0f, 0x01, 0xde);
67 MAKE_INSTR(MOV2CR, 3, 0x0f, 0x22, 0x00);
68 MAKE_INSTR(MOVCR2, 3, 0x0f, 0x20, 0x00);
69 MAKE_INSTR(MOV2DR, 3, 0x0f, 0x23, 0x00);
70 MAKE_INSTR(MOVDR2, 3, 0x0f, 0x21, 0x00);
71 MAKE_INSTR(PUSHF, 1, 0x9c);
72 MAKE_INSTR(POPF, 1, 0x9d);
73 MAKE_INSTR(RSM, 2, 0x0f, 0xaa);
74 MAKE_INSTR(INVLPG, 3, 0x0f, 0x01, 0x00);
75 MAKE_INSTR(INVLPGA,3, 0x0f, 0x01, 0xdf);
76 MAKE_INSTR(HLT, 1, 0xf4);
77 MAKE_INSTR(CLTS, 2, 0x0f, 0x06);
78 MAKE_INSTR(LMSW, 3, 0x0f, 0x01, 0x00);
79 MAKE_INSTR(SMSW, 3, 0x0f, 0x01, 0x00);
82 static const uchar_t PREFIX_LOCK = 0xF0;
83 static const uchar_t PREFIX_REPNE = 0xF2;
84 static const uchar_t PREFIX_REPNZ = 0xF2;
85 static const uchar_t PREFIX_REP = 0xF3;
86 static const uchar_t PREFIX_REPE = 0xF3;
87 static const uchar_t PREFIX_REPZ = 0xF3;
88 static const uchar_t PREFIX_CS_OVERRIDE = 0x2E;
89 static const uchar_t PREFIX_SS_OVERRIDE = 0x36;
90 static const uchar_t PREFIX_DS_OVERRIDE = 0x3E;
91 static const uchar_t PREFIX_ES_OVERRIDE = 0x26;
92 static const uchar_t PREFIX_FS_OVERRIDE = 0x64;
93 static const uchar_t PREFIX_GS_OVERRIDE = 0x65;
94 static const uchar_t PREFIX_BR_NOT_TAKEN = 0x2E;
95 static const uchar_t PREFIX_BR_TAKEN = 0x3E;
96 static const uchar_t PREFIX_OP_SIZE = 0x66;
97 static const uchar_t PREFIX_ADDR_SIZE = 0x67;
100 static inline int is_prefix_byte(char byte) {
103 case 0xF2: // REPNE/REPNZ
104 case 0xF3: // REP or REPE/REPZ
105 case 0x2E: // CS override or Branch hint not taken (with Jcc instrs)
106 case 0x36: // SS override
107 case 0x3E: // DS override or Branch hint taken (with Jcc instrs)
108 case 0x26: // ES override
109 case 0x64: // FS override
110 case 0x65: // GS override
111 //case 0x2E: // branch not taken hint
112 // case 0x3E: // branch taken hint
113 case 0x66: // operand size override
114 case 0x67: // address size override
125 static inline addr_t get_addr_linear(struct guest_info * info, addr_t addr, addr_t seg_base) {
126 switch (info->cpu_mode) {
128 return addr + (seg_base << 4);
132 return addr + seg_base;
140 typedef enum {INVALID_ADDR_TYPE, REG, DISP0, DISP8, DISP16, DISP32} modrm_mode_t;
141 typedef enum {INVALID_REG_SIZE, REG64, REG32, REG16, REG8} reg_size_t;
142 typedef enum {INVALID_OPERAND, REG_OPERAND, MEM_OPERAND} operand_type_t;
146 static inline addr_t decode_register(struct guest_gprs * gprs, char reg_code, reg_size_t reg_size) {
151 reg_addr = (addr_t)&(gprs->rax);
154 reg_addr = (addr_t)&(gprs->rcx);
157 reg_addr = (addr_t)&(gprs->rdx);
160 reg_addr = (addr_t)&(gprs->rbx);
163 if (reg_size == REG8) {
164 reg_addr = (addr_t)&(gprs->rax) + 1;
166 reg_addr = (addr_t)&(gprs->rsp);
170 if (reg_size == REG8) {
171 reg_addr = (addr_t)&(gprs->rcx) + 1;
173 reg_addr = (addr_t)&(gprs->rbp);
177 if (reg_size == REG8) {
178 reg_addr = (addr_t)&(gprs->rdx) + 1;
180 reg_addr = (addr_t)&(gprs->rsi);
184 if (reg_size == REG8) {
185 reg_addr = (addr_t)&(gprs->rbx) + 1;
187 reg_addr = (addr_t)&(gprs->rdi);
200 static inline operand_type_t decode_operands16(struct guest_gprs * gprs, // input/output
201 char * modrm_instr, // input
202 int * offset, // output
203 addr_t * first_operand, // output
204 addr_t * second_operand, // output
205 reg_size_t reg_size) { // input
207 struct modrm_byte * modrm = (struct modrm_byte *)modrm_instr;
208 addr_t base_addr = 0;
209 modrm_mode_t mod_mode = 0;
210 operand_type_t addr_type = INVALID_OPERAND;
211 char * instr_cursor = modrm_instr;
213 PrintDebug("ModRM mod=%d\n", modrm->mod);
217 if (modrm->mod == 3) {
219 addr_type = REG_OPERAND;
220 PrintDebug("first operand = Register (RM=%d)\n",modrm->rm);
222 *first_operand = decode_register(gprs, modrm->rm, reg_size);
226 addr_type = MEM_OPERAND;
228 if (modrm->mod == 0) {
230 } else if (modrm->mod == 1) {
232 } else if (modrm->mod == 2) {
238 base_addr = gprs->rbx + gprs->rsi;
241 base_addr = gprs->rbx + gprs->rdi;
244 base_addr = gprs->rbp + gprs->rsi;
247 base_addr = gprs->rbp + gprs->rdi;
250 base_addr = gprs->rsi;
253 base_addr = gprs->rdi;
256 if (modrm->mod == 0) {
260 base_addr = gprs->rbp;
264 base_addr = gprs->rbx;
270 if (mod_mode == DISP8) {
271 base_addr += (uchar_t)*(instr_cursor);
273 } else if (mod_mode == DISP16) {
274 base_addr += (ushort_t)*(instr_cursor);
278 *first_operand = base_addr;
281 *offset += (instr_cursor - modrm_instr);
282 *second_operand = decode_register(gprs, modrm->reg, reg_size);
289 static inline operand_type_t decode_operands32(struct guest_gprs * gprs, // input/output
290 char * modrm_instr, // input
291 int * offset, // output
292 addr_t * first_operand, // output
293 addr_t * second_operand, // output
294 reg_size_t reg_size) { // input
296 char * instr_cursor = modrm_instr;
297 struct modrm_byte * modrm = (struct modrm_byte *)modrm_instr;
298 addr_t base_addr = 0;
299 modrm_mode_t mod_mode = 0;
300 uint_t has_sib_byte = 0;
301 operand_type_t addr_type = INVALID_OPERAND;
307 if (modrm->mod == 3) {
309 addr_type = REG_OPERAND;
311 PrintDebug("first operand = Register (RM=%d)\n",modrm->rm);
313 *first_operand = decode_register(gprs, modrm->rm, reg_size);
317 addr_type = MEM_OPERAND;
319 if (modrm->mod == 0) {
321 } else if (modrm->mod == 1) {
323 } else if (modrm->mod == 2) {
329 base_addr = gprs->rax;
332 base_addr = gprs->rcx;
335 base_addr = gprs->rdx;
338 base_addr = gprs->rbx;
344 if (modrm->mod == 0) {
348 base_addr = gprs->rbp;
352 base_addr = gprs->rsi;
355 base_addr = gprs->rdi;
361 struct sib_byte * sib = (struct sib_byte *)(instr_cursor);
367 if (sib->scale == 1) {
369 } else if (sib->scale == 2) {
371 } else if (sib->scale == 3) {
376 switch (sib->index) {
378 base_addr = gprs->rax;
381 base_addr = gprs->rcx;
384 base_addr = gprs->rdx;
387 base_addr = gprs->rbx;
393 base_addr = gprs->rbp;
396 base_addr = gprs->rsi;
399 base_addr = gprs->rdi;
408 base_addr += gprs->rax;
411 base_addr += gprs->rcx;
414 base_addr += gprs->rdx;
417 base_addr += gprs->rbx;
420 base_addr += gprs->rsp;
423 if (modrm->mod != 0) {
424 base_addr += gprs->rbp;
428 base_addr += gprs->rsi;
431 base_addr += gprs->rdi;
438 if (mod_mode == DISP8) {
439 base_addr += (uchar_t)*(instr_cursor);
441 } else if (mod_mode == DISP32) {
442 base_addr += (uint_t)*(instr_cursor);
447 *first_operand = base_addr;
450 *offset += (instr_cursor - modrm_instr);
452 *second_operand = decode_register(gprs, modrm->reg, reg_size);