Palacios Public Git Repository

To checkout Palacios execute

  git clone http://v3vee.org/palacios/palacios.web/palacios.git
This will give you the master branch. You probably want the devel branch or one of the release branches. To switch to the devel branch, simply execute
  cd palacios
  git checkout --track -b devel origin/devel
The other branches are similar.


working instruction emulation
[palacios.git] / palacios / src / palacios / vmm_emulator.c
index fcce7c3..bb67a5f 100644 (file)
+/* 
+ * This file is part of the Palacios Virtual Machine Monitor developed
+ * by the V3VEE Project with funding from the United States National 
+ * Science Foundation and the Department of Energy.  
+ *
+ * The V3VEE Project is a joint project between Northwestern University
+ * and the University of New Mexico.  You can find out more at 
+ * http://www.v3vee.org
+ *
+ * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu> 
+ * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org> 
+ * All rights reserved.
+ *
+ * Author: Jack Lange <jarusl@cs.northwestern.edu>
+ *
+ * This is free software.  You are permitted to use,
+ * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
+ */
+
 #include <palacios/vmm.h>
 #include <palacios/vmm_emulator.h>
 #include <palacios/vm_guest_mem.h>
 #include <palacios/vmm_decoder.h>
+#include <palacios/vmm_paging.h>
+#include <palacios/vmm_instr_emulator.h>
 
-static const char VMMCALL[3] = {0x0f, 0x01, 0xd9};
+#ifndef DEBUG_EMULATOR
+#undef PrintDebug
+#define PrintDebug(fmt, args...)
+#endif
 
-int init_emulator(struct guest_info * info) {
-  struct emulation_state * emulator = &(info->emulator);
 
-  emulator->num_emulated_pages = 0;
-  INIT_LIST_HEAD(&(emulator->emulated_pages));
 
 
-  emulator->num_saved_pages = 0;
-  INIT_LIST_HEAD(&(emulator->saved_pages));
-  
-  emulator->num_write_regions = 0;
-  INIT_LIST_HEAD(&(emulator->write_regions));
 
-  emulator->running = 0;
-  emulator->instr_length = 0;
 
-  return 0;
-}
+// We emulate up to the next 4KB page boundry
+static int emulate_string_write_op(struct guest_info * info, struct x86_instr * dec_instr, 
+                                  addr_t write_gva, addr_t write_gpa, addr_t * dst_addr) {
+  uint_t emulation_length = 0;
+  addr_t tmp_rcx = 0;
+  addr_t src_addr = 0;
 
-static addr_t get_new_page() {
-  void * page = V3_AllocPages(1);
-  memset(page, 0, PAGE_SIZE);
+  if (dec_instr->op_type == V3_OP_MOVS) {
+    PrintDebug("MOVS emulation\n");
 
-  return (addr_t)page;
-}
+    if (dec_instr->dst_operand.operand != write_gva) {
+      PrintError("Inconsistency between Pagefault and Instruction Decode XED_ADDR=%p, PF_ADDR=%p\n",
+                (void *)dec_instr->dst_operand.operand, (void *)write_gva);
+      return -1;
+    }
 
+    emulation_length = ( (dec_instr->str_op_length  < (0x1000 - PAGE_OFFSET_4KB(write_gva))) ? 
+                        dec_instr->str_op_length :
+                        (0x1000 - PAGE_OFFSET_4KB(write_gva)));
+    /* ** Fix emulation length so that it doesn't overrun over the src page either ** */
 
-static int setup_code_page(struct guest_info * info, char * instr, struct basic_instr_info * instr_info ) {
-  addr_t code_page_offset = PT32_PAGE_OFFSET(info->rip);
-  addr_t code_page = get_new_page();
-  struct emulated_page * new_code_page = V3_Malloc(sizeof(struct emulated_page));
-  struct saved_page * saved_code_page = V3_Malloc(sizeof(struct saved_page));
 
+    PrintDebug("STR_OP_LEN: %d, Page Len: %d\n", 
+              (uint_t)dec_instr->str_op_length, 
+              (uint_t)(0x1000 - PAGE_OFFSET_4KB(write_gva)));
+    PrintDebug("Emulation length: %d\n", emulation_length);
+    tmp_rcx = emulation_length;
+    if (guest_pa_to_host_va(info, write_gpa, dst_addr) == -1) {
+      PrintError("Could not translate write destination to host VA\n");
+      return -1;
+    }
 
-  saved_code_page->va = PT32_PAGE_ADDR(info->rip);
+    // figure out addresses here....
+    if (info->mem_mode == PHYSICAL_MEM) {
+      if (guest_pa_to_host_va(info, dec_instr->src_operand.operand, &src_addr) == -1) {
+       PrintError("Could not translate write Source (Physical) to host VA\n");
+       return -1;
+      }
+    } else {
+      if (guest_va_to_host_va(info, dec_instr->src_operand.operand, &src_addr) == -1) {
+       PrintError("Could not translate write Source (Virtual) to host VA\n");
+       return -1;
+      }
+    }
 
-  new_code_page->page_addr = code_page; 
-  new_code_page->va = PT32_PAGE_ADDR(info->rip);
 
-  new_code_page->pte.present = 1;
-  new_code_page->pte.writable = 0;
-  new_code_page->pte.user_page = 1;
-  new_code_page->pte.page_base_addr = PT32_BASE_ADDR(code_page);
+    PrintDebug("Dst Operand: %p (size=%d), Src Operand: %p\n", 
+              (void *)dec_instr->dst_operand.operand, 
+              dec_instr->dst_operand.size,
+              (void *)dec_instr->src_operand.operand);
+    PrintDebug("Dst Addr: %p, Src Addr: %p\n", (void *)(addr_t *)*dst_addr, (void *)src_addr);
 
-  memcpy((void *)(code_page + code_page_offset), instr, instr_info->instr_length);
-  memcpy((void *)(code_page + code_page_offset + instr_info->instr_length), VMMCALL, 3);
+    //return -1;
 
-  PrintDebug("New Instr Stream:\n");
-  PrintTraceMemDump((void *)(code_page + code_page_offset), 32);
-  PrintDebug("rip =%x\n", info->rip);
 
 
 
+    if (dec_instr->dst_operand.size == 1) {
+      movs8(dst_addr, &src_addr, &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
+    } else if (dec_instr->dst_operand.size == 2) {
+      movs16(dst_addr, &src_addr, &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
+    } else if (dec_instr->dst_operand.size == 4) {
+      movs32(dst_addr, &src_addr, &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
+    } else {
+      PrintError("Invalid operand length\n");
+      return -1;
+    }
 
-  v3_replace_shdw_page32(info, new_code_page->va, &(new_code_page->pte), &(saved_code_page->pte));
 
 
-  list_add(&(new_code_page->page_list), &(info->emulator.emulated_pages));
-  info->emulator.num_emulated_pages++;
 
-  list_add(&(saved_code_page->page_list), &(info->emulator.saved_pages));
-  info->emulator.num_saved_pages++;
 
-  return 0;
-}
+    PrintDebug("RDI=%p, RSI=%p, RCX=%p\n", 
+              (void *)*(addr_t *)&(info->vm_regs.rdi), 
+              (void *)*(addr_t *)&(info->vm_regs.rsi), 
+              (void *)*(addr_t *)&(info->vm_regs.rcx)); 
 
+    info->vm_regs.rdi += emulation_length;
+    info->vm_regs.rsi += emulation_length;
+    info->vm_regs.rcx -= emulation_length;
+    
+    PrintDebug("RDI=%p, RSI=%p, RCX=%p\n", 
+              (void *)*(addr_t *)&(info->vm_regs.rdi), 
+              (void *)*(addr_t *)&(info->vm_regs.rsi), 
+              (void *)*(addr_t *)&(info->vm_regs.rcx)); 
 
-// get the current instr
-// check if rep + remove
-// put into new page, vmexit after
-// replace new page with current eip page
-// 
-int v3_emulate_memory_read(struct guest_info * info, addr_t read_gva, 
-                          int (*read)(addr_t read_addr, void * dst, uint_t length, void * priv_data), 
-                          addr_t read_gpa, void * private_data) {
-  struct basic_instr_info instr_info;
-  char instr[15];
-  int ret;
-  struct emulated_page * data_page = V3_Malloc(sizeof(struct emulated_page));
-  addr_t data_addr_offset = PT32_PAGE_OFFSET(read_gva);
-  pte32_t saved_pte;
-
-  PrintDebug("Emulating Read\n");
+    if (emulation_length == dec_instr->str_op_length) {
+      info->rip += dec_instr->instr_length;
+    }
 
-  if (info->mem_mode == PHYSICAL_MEM) { 
-    ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
-  } else { 
-    ret = read_guest_va_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
+    return emulation_length;
   }
 
-  PrintDebug("Instr (15 bytes) at %x:\n", instr);
-  PrintTraceMemDump(instr, 15);
   
-  if (v3_basic_mem_decode(info, (addr_t)instr, &instr_info) == -1) {
-    PrintError("Could not do a basic memory instruction decode\n");
-    V3_Free(data_page);
-    return -1;
-  }
-
-  if (instr_info.has_rep == 1) {
-    PrintError("We currently don't handle rep* instructions\n");
-    V3_Free(data_page);
-    return -1;
-  }
-
 
-  data_page->page_addr = get_new_page();
-  data_page->va = PT32_PAGE_ADDR(read_gva);
-  data_page->pte.present = 1;
-  data_page->pte.writable = 0;
-  data_page->pte.user_page = 1;
-  data_page->pte.page_base_addr = PT32_BASE_ADDR(data_page->page_addr);
 
-
-  // Read the data directly onto the emulated page
-  if (read(read_gpa, (void *)(data_page->page_addr + data_addr_offset), instr_info.op_size, private_data) != instr_info.op_size) {
-    PrintError("Read error in emulator\n");
-    V3_FreePage((void *)(data_page->page_addr));
-    V3_Free(data_page);
-    return -1;
-  }
-
-  v3_replace_shdw_page32(info, data_page->va, &(data_page->pte), &saved_pte);
-
-
-  list_add(&(data_page->page_list), &(info->emulator.emulated_pages));
-  info->emulator.num_emulated_pages++;
-
-  if (saved_pte.present == 1) {
-    struct saved_page * saved_data_page = V3_Malloc(sizeof(struct saved_page));
-    saved_data_page->pte = saved_pte;
-    saved_data_page->va = PT32_PAGE_ADDR(read_gva);
-
-    list_add(&(saved_data_page->page_list), &(info->emulator.saved_pages));
-    info->emulator.num_saved_pages++;
-  }
-
-
-  setup_code_page(info, instr, &instr_info);
-
-  info->emulator.running = 1;
-  info->run_state = VM_EMULATING;
-  info->emulator.instr_length = instr_info.instr_length;
-
-  return 0;
+  return -1;
 }
 
 
+int v3_emulate_write_op(struct guest_info * info, addr_t write_gva, addr_t write_gpa, addr_t * dst_addr) {
+  struct x86_instr dec_instr;
+  uchar_t instr[15];
+  int ret = 0;
+  addr_t src_addr = 0;
 
-int v3_emulate_memory_write(struct guest_info * info, addr_t write_gva,
-                           int (*write)(addr_t write_addr, void * src, uint_t length, void * priv_data), 
-                           addr_t write_gpa, void * private_data) {
-
-  struct basic_instr_info instr_info;
-  char instr[15];
-  int ret;
-  struct write_region * write_op = V3_Malloc(sizeof(struct write_region ));
-  struct emulated_page * data_page = V3_Malloc(sizeof(struct emulated_page));
-  addr_t data_addr_offset = PT32_PAGE_OFFSET(write_gva);
-  pte32_t saved_pte;
 
-  PrintDebug("Emulating Write\n");
+  PrintDebug("Emulating Write for instruction at %p\n", (void *)(addr_t)(info->rip));
+  PrintDebug("GPA=%p, GVA=%p\n", (void *)write_gpa, (void *)write_gva);
 
   if (info->mem_mode == PHYSICAL_MEM) { 
     ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
   } else { 
     ret = read_guest_va_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
   }
-  
-  if (v3_basic_mem_decode(info, (addr_t)instr, &instr_info) == -1) {
-    PrintError("Could not do a basic memory instruction decode\n");
-    V3_Free(write_op);
-    V3_Free(data_page);
-    return -1;
-  }
 
-  if (instr_info.has_rep == 1) {
-    PrintError("We currently don't handle rep* instructions\n");
-    V3_Free(write_op);
-    V3_Free(data_page);
+  if (ret == -1) {
     return -1;
   }
 
 
-  data_page->page_addr = get_new_page();
-  data_page->va = PT32_PAGE_ADDR(write_gva);
-  data_page->pte.present = 1;
-  data_page->pte.writable = 1;
-  data_page->pte.user_page = 1;
-  data_page->pte.page_base_addr = PT32_BASE_ADDR(data_page->page_addr);
-
-
-
-  write_op->write = write;
-  write_op->write_addr = write_gpa;
-  write_op->length = instr_info.op_size;
-  write_op->private_data = private_data;
-
-  write_op->write_data = (void *)(data_page->page_addr + data_addr_offset);
-
-  list_add(&(write_op->write_list), &(info->emulator.write_regions));
-  info->emulator.num_write_regions--;
-
-  v3_replace_shdw_page32(info, data_page->va, &(data_page->pte), &saved_pte);
-
-
-  list_add(&(data_page->page_list), &(info->emulator.emulated_pages));
-  info->emulator.num_emulated_pages++;
-
-  if (saved_pte.present == 1) {
-    struct saved_page * saved_data_page = V3_Malloc(sizeof(struct saved_page));
-    saved_data_page->pte = saved_pte;
-    saved_data_page->va = PT32_PAGE_ADDR(write_gva);
-
-    list_add(&(saved_data_page->page_list), &(info->emulator.saved_pages));
-    info->emulator.num_saved_pages++;
+  if (guest_pa_to_host_va(info, write_gpa, dst_addr) == -1) {
+    PrintError("Could not translate write destination to host VA\n");
+    return -1;
   }
 
-
-  if (info->emulator.running == 0) {
-    setup_code_page(info, instr, &instr_info);
-    info->emulator.running = 1;
-    info->run_state = VM_EMULATING;
-    info->emulator.instr_length = instr_info.instr_length;
+  if (v3_decode(info, (addr_t)instr, &dec_instr) == -1) {
+    PrintError("Decoding Error\n");
+    // Kick off single step emulator
+    return -1;
   }
-
-  return 0;
-}
-
-
-// end emulation
-int v3_emulation_exit_handler(struct guest_info * info) {
-  struct saved_page * svpg, * p_svpg;
-  struct emulated_page * empg, * p_empg;
-  struct write_region * wr_reg, * p_wr_reg;
-  pte32_t dummy_pte;
-
-  // Complete the writes
-  // delete writes
-  // swap out emulated pages with blank dummies
-  // swap in saved pages
-  // increment rip
   
-  PrintDebug("V3 Emulation Exit Handler\n");
-
-  list_for_each_entry_safe(wr_reg, p_wr_reg, &(info->emulator.write_regions), write_list) {
-    wr_reg->write(wr_reg->write_addr, wr_reg->write_data, wr_reg->length, wr_reg->private_data);
-    PrintDebug("Writing \n");
-    
-    list_del(&(wr_reg->write_list));
-    V3_Free(wr_reg);
-
+  if (dec_instr.is_str_op) {
+    return emulate_string_write_op(info, &dec_instr, write_gva, write_gpa, dst_addr);
   }
-  info->emulator.num_write_regions = 0;
-
-
-  *(uint_t *)&dummy_pte = 0;
-  
-  list_for_each_entry_safe(empg, p_empg, &(info->emulator.emulated_pages), page_list) {
-    pte32_t empte32_t;
-
-    PrintDebug("wiping page %x\n", empg->va); 
 
-    v3_replace_shdw_page32(info, empg->va, &dummy_pte, &empte32_t);
-    V3_FreePage((void *)(empg->page_addr));
 
-    list_del(&(empg->page_list));
-    V3_Free(empg);
+  if ((dec_instr.dst_operand.type != MEM_OPERAND) ||
+      (dec_instr.dst_operand.operand != write_gva)) {
+    PrintError("Inconsistency between Pagefault and Instruction Decode XED_ADDR=%p, PF_ADDR=%p\n",
+              (void *)dec_instr.dst_operand.operand, (void *)write_gva);
+    return -1;
   }
-  info->emulator.num_emulated_pages = 0;
 
-  list_for_each_entry_safe(svpg, p_svpg, &(info->emulator.saved_pages), page_list) {
 
-    PrintDebug("Setting Saved page %x back\n", svpg->va); 
-    v3_replace_shdw_page32(info, empg->va, &(svpg->pte), &dummy_pte);
-    
-    list_del(&(svpg->page_list));
-    V3_Free(svpg);
+  if (dec_instr.src_operand.type == MEM_OPERAND) {
+    if (info->mem_mode == PHYSICAL_MEM) {
+      if (guest_pa_to_host_va(info, dec_instr.src_operand.operand, &src_addr) == -1) {
+       PrintError("Could not translate write Source (Physical) to host VA\n");
+       return -1;
+      }
+    } else {
+      if (guest_va_to_host_va(info, dec_instr.src_operand.operand, &src_addr) == -1) {
+       PrintError("Could not translate write Source (Virtual) to host VA\n");
+       return -1;
+      }
+    }
+  } else if (dec_instr.src_operand.type == REG_OPERAND) {
+    src_addr = dec_instr.src_operand.operand;
+  } else {
+    src_addr = (addr_t)&(dec_instr.src_operand.operand);
   }
-  info->emulator.num_saved_pages = 0;
 
-  info->run_state = VM_RUNNING;
-  info->emulator.running = 0;
-  //info->rip += info->emulator.instr_length;
 
-  info->emulator.instr_length = 0;
+  PrintDebug("Dst_Addr Ptr = %p (val=%p), SRC operand = %p\n", 
+            (void *)dst_addr, (void *)*dst_addr, (void *)src_addr);
+
+
+  if (dec_instr.dst_operand.size == 1) {
+
+    switch (dec_instr.op_type) {
+    case V3_OP_ADC:
+      adc8((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_ADD:
+      add8((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_AND:
+      and8((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_OR:
+      or8((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_XOR:
+      xor8((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SUB:
+      sub8((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+
+    case V3_OP_MOV:
+      mov8((addr_t *)*dst_addr, (addr_t *)src_addr);
+      break;
+    case V3_OP_NOT:
+      not8((addr_t *)*dst_addr);
+      break;
+    case V3_OP_XCHG:
+      xchg8((addr_t *)*dst_addr, (addr_t *)src_addr);
+      break;
+      
+
+    case V3_OP_INC:
+      inc8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_DEC:
+      dec8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_NEG:
+      neg8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SETB:
+      setb8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SETBE:
+      setbe8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SETL:
+      setl8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SETLE:
+      setle8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SETNB:
+      setnb8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SETNBE:
+      setnbe8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SETNL:
+      setnl8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SETNLE:
+      setnle8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SETNO:
+      setno8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SETNP:
+      setnp8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SETNS:
+      setns8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SETNZ:
+      setnz8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SETO:
+      seto8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SETP:
+      setp8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SETS:
+      sets8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SETZ:
+      setz8((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+
+    default:
+      PrintError("Unknown 8 bit instruction\n");
+      return -1;
+    }
+
+  } else if (dec_instr.dst_operand.size == 2) {
+
+    switch (dec_instr.op_type) {
+    case V3_OP_ADC:
+      adc16((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_ADD:
+      add16((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_AND:
+      and16((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_OR:
+      or16((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_XOR:
+      xor16((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SUB:
+      sub16((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+
+
+    case V3_OP_INC:
+      inc16((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_DEC:
+      dec16((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_NEG:
+      neg16((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+
+    case V3_OP_MOV:
+      mov16((addr_t *)*dst_addr, (addr_t *)src_addr);
+      break;
+    case V3_OP_NOT:
+      not16((addr_t *)*dst_addr);
+      break;
+    case V3_OP_XCHG:
+      xchg16((addr_t *)*dst_addr, (addr_t *)src_addr);
+      break;
+      
+    default:
+      PrintError("Unknown 16 bit instruction\n");
+      return -1;
+    }
+
+  } else if (dec_instr.dst_operand.size == 4) {
+
+    switch (dec_instr.op_type) {
+    case V3_OP_ADC:
+      adc32((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_ADD:
+      add32((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_AND:
+      and32((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_OR:
+      or32((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_XOR:
+      xor32((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_SUB:
+      sub32((addr_t *)*dst_addr, (addr_t *)src_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+
+    case V3_OP_INC:
+      inc32((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_DEC:
+      dec32((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+    case V3_OP_NEG:
+      neg32((addr_t *)*dst_addr, (addr_t *)&(info->ctrl_regs.rflags));
+      break;
+
+    case V3_OP_MOV:
+      mov32((addr_t *)*dst_addr, (addr_t *)src_addr);
+      break;
+    case V3_OP_NOT:
+      not32((addr_t *)*dst_addr);
+      break;
+    case V3_OP_XCHG:
+      xchg32((addr_t *)*dst_addr, (addr_t *)src_addr);
+      break;
+      
+    default:
+      PrintError("Unknown 32 bit instruction\n");
+      return -1;
+    }
+
+  } else if (dec_instr.dst_operand.size == 8) {
+    PrintError("64 bit instructions not handled\n");
+    return -1;
+  } else {
+    PrintError("Invalid Operation Size\n");
+    return -1;
+  }
 
-  PrintDebug("returning from emulation\n");
+  info->rip += dec_instr.instr_length;
 
-  return 0;
+  return dec_instr.dst_operand.size;
 }
+