#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 & 0x07)
+
+struct modrm_byte {
+ uint_t rm : 3 PACKED;
+ uint_t reg : 3 PACKED;
+ uint_t mod : 2 PACKED;
+};
+
+
+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__ }
}
}
+typedef enum {INVALID_ADDR_TYPE, REG, DISP0, DISP8, DISP16, DISP32} modrm_addr_type_t;
+typedef enum {INVALID_REG_SIZE, REG64, REG32, REG16, REG8} reg_size_t;
+typedef enum {INVALID_OPERAND_TYPE, REG_TO_REG, REG_TO_MEM, MEM_TO_REG} operand_type_t;
+
+struct guest_gprs;
+
+
+static inline int decode_operands16(struct guest_gprs * gprs,
+ char * modrm_instr,
+ addr_t * first_operand,
+ addr_t * second_operand,
+ reg_size_t reg_size) {
+
+ struct modrm_byte * modrm = (struct modrm_byte*)modrm_instr;
+ addr_t base_addr = 0;
+ modrm_addr_type_t mod_type = 0;
+
+ PrintDebug("ModRM mod=%d\n", modrm->mod);
+
+ if (modrm->mod == 3) {
+ mod_type = REG;
+
+ PrintDebug("first operand = Register (RM=%d)\n",modrm->rm);
+
+ switch (modrm->rm) {
+ case 0:
+ PrintDebug("EAX Operand\n");
+ *first_operand = (addr_t)&(gprs->rax);
+ break;
+ case 1:
+ *first_operand = (addr_t)&(gprs->rcx);
+ break;
+ case 2:
+ *first_operand = (addr_t)&(gprs->rdx);
+ break;
+ case 3:
+ *first_operand = (addr_t)&(gprs->rbx);
+ break;
+ case 4:
+ if (reg_size == REG8) {
+ *first_operand = (addr_t)(&(gprs->rax) + 1);
+ } else {
+ *first_operand = (addr_t)&(gprs->rsp);
+ }
+ break;
+ case 5:
+ if (reg_size == REG8) {
+ *first_operand = (addr_t)(&(gprs->rcx) + 1);
+ } else {
+ *first_operand = (addr_t)&(gprs->rbp);
+ }
+ break;
+ case 6:
+ if (reg_size == REG8) {
+ *first_operand = (addr_t)(&(gprs->rdx) + 1);
+ } else {
+ *first_operand = (addr_t)&(gprs->rsi);
+ }
+ break;
+ case 7:
+ if (reg_size == REG8) {
+ *first_operand = (addr_t)(&(gprs->rbx) + 1);
+ } else {
+ *first_operand = (addr_t)&(gprs->rdi);
+ }
+ break;
+ }
+
+ } else {
+ if (modrm->mod == 0) {
+ mod_type = DISP0;
+ } else if (modrm->mod == 1) {
+ mod_type = DISP8;
+ } else if (modrm->mod == 2) {
+ mod_type = DISP16;
+ }
+
+ switch (modrm->rm) {
+ case 0:
+ base_addr = gprs->rbx + gprs->rsi;
+ case 1:
+ base_addr = gprs->rbx + gprs->rdi;
+ case 2:
+ base_addr = gprs->rbp + gprs->rsi;
+ case 3:
+ base_addr = gprs->rbp + gprs->rdi;
+ case 4:
+ base_addr = gprs->rsi;
+ case 5:
+ base_addr = gprs->rdi;
+ case 6:
+ if (modrm->mod == 0) {
+ base_addr = 0;
+ mod_type = DISP16;
+ } else {
+ base_addr = gprs->rbp;
+ }
+ case 7:
+ base_addr = gprs->rbx;
+ }
+
+ if (mod_type == DISP8) {
+ base_addr += (uchar_t)*(modrm_instr + 1);
+ } else if (mod_type == DISP16) {
+ base_addr += (ushort_t)*(modrm_instr + 1);
+ }
+
+
+ *first_operand = base_addr;
+ }
+
+
+
+ switch (modrm->reg) {
+ case 0:
+ *second_operand = (addr_t)&(gprs->rax);
+ break;
+ case 1:
+ *second_operand = (addr_t)&(gprs->rcx);
+ break;
+ case 2:
+ *second_operand = (addr_t)&(gprs->rdx);
+ break;
+ case 3:
+ *second_operand = (addr_t)&(gprs->rbx);
+ break;
+ case 4:
+ if (reg_size == REG8) {
+ *second_operand = (addr_t)&(gprs->rax) + 1;
+ } else {
+ *second_operand = (addr_t)&(gprs->rsp);
+ }
+ break;
+ case 5:
+ if (reg_size == REG8) {
+ *second_operand = (addr_t)&(gprs->rcx) + 1;
+ } else {
+ *second_operand = (addr_t)&(gprs->rbp);
+ }
+ break;
+ case 6:
+ if (reg_size == REG8) {
+ *second_operand = (addr_t)&(gprs->rdx) + 1;
+ } else {
+ *second_operand = (addr_t)&(gprs->rsi);
+ }
+ break;
+ case 7:
+ if (reg_size == REG8) {
+ *second_operand = (addr_t)&(gprs->rbx) + 1;
+ } else {
+ *second_operand = (addr_t)&(gprs->rdi);
+ }
+ break;
+ }
+
+ return 0;
+
+}
