#ifndef __VMM_EMULATE_H
#define __VMM_EMULATE_H
+#include <geekos/vm_guest.h>
-/* JRL: Most of this was taken from the Xen sources...
+/*
+ * This is where we do the hideous X86 instruction parsing among other things
+ * We can parse out the instruction prefixes, as well as decode the operands
+ *
+ * Before we begin I'd just like to say a few words to those that made this possible...
+ *
+ *
+ * _____
+ * || ||
+ * |\___/|
+ * | |
+ * | |
+ * | |
+ * | |
+ * | |
+ * | |
+ * _____|<--->|_____
+ * ___/ | | \
+ * / | | | | \
+ * | | | | | |
+ * | | | | | |
+ * | | |
+ * | | |
+ * | Fuck You Intel! /
+ * | /
+ * \ /
+ * \ /
+ * | |
+ * | |
+ *
+ * That is all.
*
*/
+/* JRL: Some of this was taken from the Xen sources...
+ *
+ */
+
+#define PACKED __attribute__((packed))
+
+#define MODRM_MOD(x) ((x >> 6) & 0x3)
+#define MODRM_REG(x) ((x >> 3) & 0x7)
+#define MODRM_RM(x) (x & 0x7)
+
+struct modrm_byte {
+ uint_t rm : 3 PACKED;
+ uint_t reg : 3 PACKED;
+ uint_t mod : 2 PACKED;
+};
+
+
+#define SIB_BASE(x) ((x >> 6) & 0x3)
+#define SIB_INDEX(x) ((x >> 3) & 0x7)
+#define SIB_SCALE(x) (x & 0x7)
+
+struct sib_byte {
+ uint_t base : 3 PACKED;
+ uint_t index : 3 PACKED;
+ uint_t scale : 2 PACKED;
+};
+
+
+
#define MAKE_INSTR(nm, ...) static const uchar_t OPCODE_##nm[] = { __VA_ARGS__ }
/*
MAKE_INSTR(SMSW, 3, 0x0f, 0x01, 0x00);
+static const uchar_t PREFIX_LOCK = 0xF0;
+static const uchar_t PREFIX_REPNE = 0xF2;
+static const uchar_t PREFIX_REPNZ = 0xF2;
+static const uchar_t PREFIX_REP = 0xF3;
+static const uchar_t PREFIX_REPE = 0xF3;
+static const uchar_t PREFIX_REPZ = 0xF3;
+static const uchar_t PREFIX_CS_OVERRIDE = 0x2E;
+static const uchar_t PREFIX_SS_OVERRIDE = 0x36;
+static const uchar_t PREFIX_DS_OVERRIDE = 0x3E;
+static const uchar_t PREFIX_ES_OVERRIDE = 0x26;
+static const uchar_t PREFIX_FS_OVERRIDE = 0x64;
+static const uchar_t PREFIX_GS_OVERRIDE = 0x65;
+static const uchar_t PREFIX_BR_NOT_TAKEN = 0x2E;
+static const uchar_t PREFIX_BR_TAKEN = 0x3E;
+static const uchar_t PREFIX_OP_SIZE = 0x66;
+static const uchar_t PREFIX_ADDR_SIZE = 0x67;
+
static inline int is_prefix_byte(char byte) {
switch (byte) {
+static inline addr_t get_addr_linear(struct guest_info * info, addr_t addr, addr_t seg_base) {
+ switch (info->cpu_mode) {
+ case REAL:
+ return addr + (seg_base << 4);
+ break;
+ case PROTECTED:
+ case PROTECTED_PG:
+ return addr + seg_base;
+ break;
+ default:
+ return 0;
+ }
+}
+
+
+typedef enum {INVALID_ADDR_TYPE, REG, DISP0, DISP8, DISP16, DISP32} modrm_mode_t;
+typedef enum {INVALID_REG_SIZE, REG64, REG32, REG16, REG8} reg_size_t;
+typedef enum {INVALID_OPERAND, REG_OPERAND, MEM_OPERAND} operand_type_t;
+
+struct guest_gprs;
+
+static inline addr_t decode_register(struct guest_gprs * gprs, char reg_code, reg_size_t reg_size) {
+ addr_t reg_addr;
+
+ switch (reg_code) {
+ case 0:
+ reg_addr = (addr_t)&(gprs->rax);
+ break;
+ case 1:
+ reg_addr = (addr_t)&(gprs->rcx);
+ break;
+ case 2:
+ reg_addr = (addr_t)&(gprs->rdx);
+ break;
+ case 3:
+ reg_addr = (addr_t)&(gprs->rbx);
+ break;
+ case 4:
+ if (reg_size == REG8) {
+ reg_addr = (addr_t)&(gprs->rax) + 1;
+ } else {
+ reg_addr = (addr_t)&(gprs->rsp);
+ }
+ break;
+ case 5:
+ if (reg_size == REG8) {
+ reg_addr = (addr_t)&(gprs->rcx) + 1;
+ } else {
+ reg_addr = (addr_t)&(gprs->rbp);
+ }
+ break;
+ case 6:
+ if (reg_size == REG8) {
+ reg_addr = (addr_t)&(gprs->rdx) + 1;
+ } else {
+ reg_addr = (addr_t)&(gprs->rsi);
+ }
+ break;
+ case 7:
+ if (reg_size == REG8) {
+ reg_addr = (addr_t)&(gprs->rbx) + 1;
+ } else {
+ reg_addr = (addr_t)&(gprs->rdi);
+ }
+ break;
+ default:
+ reg_addr = 0;
+ break;
+ }
+
+ return reg_addr;
+}
+
+
+
+static inline operand_type_t decode_operands16(struct guest_gprs * gprs, // input/output
+ char * modrm_instr, // input
+ int * offset, // output
+ addr_t * first_operand, // output
+ addr_t * second_operand, // output
+ reg_size_t reg_size) { // input
+
+ struct modrm_byte * modrm = (struct modrm_byte *)modrm_instr;
+ addr_t base_addr = 0;
+ modrm_mode_t mod_mode = 0;
+ operand_type_t addr_type = INVALID_OPERAND;
+ char * instr_cursor = modrm_instr;
+
+ PrintDebug("ModRM mod=%d\n", modrm->mod);
+
+ instr_cursor += 1;
+
+ if (modrm->mod == 3) {
+ mod_mode = REG;
+ addr_type = REG_OPERAND;
+ PrintDebug("first operand = Register (RM=%d)\n",modrm->rm);
+
+ *first_operand = decode_register(gprs, modrm->rm, reg_size);
+
+ } else {
+
+ addr_type = MEM_OPERAND;
+
+ if (modrm->mod == 0) {
+ mod_mode = DISP0;
+ } else if (modrm->mod == 1) {
+ mod_mode = DISP8;
+ } else if (modrm->mod == 2) {
+ mod_mode = DISP16;
+ }
+
+ switch (modrm->rm) {
+ case 0:
+ base_addr = gprs->rbx + gprs->rsi;
+ break;
+ case 1:
+ base_addr = gprs->rbx + gprs->rdi;
+ break;
+ case 2:
+ base_addr = gprs->rbp + gprs->rsi;
+ break;
+ case 3:
+ base_addr = gprs->rbp + gprs->rdi;
+ break;
+ case 4:
+ base_addr = gprs->rsi;
+ break;
+ case 5:
+ base_addr = gprs->rdi;
+ break;
+ case 6:
+ if (modrm->mod == 0) {
+ base_addr = 0;
+ mod_mode = DISP16;
+ } else {
+ base_addr = gprs->rbp;
+ }
+ break;
+ case 7:
+ base_addr = gprs->rbx;
+ break;
+ }
+
+
+
+ if (mod_mode == DISP8) {
+ base_addr += (uchar_t)*(instr_cursor);
+ instr_cursor += 1;
+ } else if (mod_mode == DISP16) {
+ base_addr += (ushort_t)*(instr_cursor);
+ instr_cursor += 2;
+ }
+
+ *first_operand = base_addr;
+ }
+
+ *offset += (instr_cursor - modrm_instr);
+ *second_operand = decode_register(gprs, modrm->reg, reg_size);
+
+ return addr_type;
+}
+
+
+
+static inline operand_type_t decode_operands32(struct guest_gprs * gprs, // input/output
+ char * modrm_instr, // input
+ int * offset, // output
+ addr_t * first_operand, // output
+ addr_t * second_operand, // output
+ reg_size_t reg_size) { // input
+
+ char * instr_cursor = modrm_instr;
+ struct modrm_byte * modrm = (struct modrm_byte *)modrm_instr;
+ addr_t base_addr = 0;
+ modrm_mode_t mod_mode = 0;
+ uint_t has_sib_byte = 0;
+ operand_type_t addr_type = INVALID_OPERAND;
+
+
+
+ instr_cursor += 1;
+
+ if (modrm->mod == 3) {
+ mod_mode = REG;
+ addr_type = REG_OPERAND;
+
+ PrintDebug("first operand = Register (RM=%d)\n",modrm->rm);
+
+ *first_operand = decode_register(gprs, modrm->rm, reg_size);
+
+ } else {
+
+ addr_type = MEM_OPERAND;
+
+ if (modrm->mod == 0) {
+ mod_mode = DISP0;
+ } else if (modrm->mod == 1) {
+ mod_mode = DISP8;
+ } else if (modrm->mod == 2) {
+ mod_mode = DISP32;
+ }
+
+ switch (modrm->rm) {
+ case 0:
+ base_addr = gprs->rax;
+ break;
+ case 1:
+ base_addr = gprs->rcx;
+ break;
+ case 2:
+ base_addr = gprs->rdx;
+ break;
+ case 3:
+ base_addr = gprs->rbx;
+ break;
+ case 4:
+ has_sib_byte = 1;
+ break;
+ case 5:
+ if (modrm->mod == 0) {
+ base_addr = 0;
+ mod_mode = DISP32;
+ } else {
+ base_addr = gprs->rbp;
+ }
+ break;
+ case 6:
+ base_addr = gprs->rsi;
+ break;
+ case 7:
+ base_addr = gprs->rdi;
+ break;
+ }
+
+ if (has_sib_byte) {
+ instr_cursor += 1;
+ struct sib_byte * sib = (struct sib_byte *)(instr_cursor);
+ int scale = 1;
+
+ instr_cursor += 1;
+
+
+ if (sib->scale == 1) {
+ scale = 2;
+ } else if (sib->scale == 2) {
+ scale = 4;
+ } else if (sib->scale == 3) {
+ scale = 8;
+ }
+
+
+ switch (sib->index) {
+ case 0:
+ base_addr = gprs->rax;
+ break;
+ case 1:
+ base_addr = gprs->rcx;
+ break;
+ case 2:
+ base_addr = gprs->rdx;
+ break;
+ case 3:
+ base_addr = gprs->rbx;
+ break;
+ case 4:
+ base_addr = 0;
+ break;
+ case 5:
+ base_addr = gprs->rbp;
+ break;
+ case 6:
+ base_addr = gprs->rsi;
+ break;
+ case 7:
+ base_addr = gprs->rdi;
+ break;
+ }
+
+ base_addr *= scale;
+
+
+ switch (sib->base) {
+ case 0:
+ base_addr += gprs->rax;
+ break;
+ case 1:
+ base_addr += gprs->rcx;
+ break;
+ case 2:
+ base_addr += gprs->rdx;
+ break;
+ case 3:
+ base_addr += gprs->rbx;
+ break;
+ case 4:
+ base_addr += gprs->rsp;
+ break;
+ case 5:
+ if (modrm->mod != 0) {
+ base_addr += gprs->rbp;
+ }
+ break;
+ case 6:
+ base_addr += gprs->rsi;
+ break;
+ case 7:
+ base_addr += gprs->rdi;
+ break;
+ }
+
+ }
+
+
+ if (mod_mode == DISP8) {
+ base_addr += (uchar_t)*(instr_cursor);
+ instr_cursor += 1;
+ } else if (mod_mode == DISP32) {
+ base_addr += (uint_t)*(instr_cursor);
+ instr_cursor += 4;
+ }
+
+
+ *first_operand = base_addr;
+ }
+
+ *offset += (instr_cursor - modrm_instr);
+
+ *second_operand = decode_register(gprs, modrm->reg, reg_size);
+
+ return addr_type;
+}
+
