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.


some nested paging fixes
[palacios.git] / palacios / src / palacios / vmm_ctrl_regs.c
index 0d29092..c02eb5c 100644 (file)
@@ -1,4 +1,4 @@
-#include <palacios/vmm_mem.h>
+ #include <palacios/vmm_mem.h>
 #include <palacios/vmm.h>
 #include <palacios/vmcb.h>
 #include <palacios/vmm_decoder.h>
@@ -6,6 +6,10 @@
 #include <palacios/vmm_ctrl_regs.h>
 
 
+
+extern void SerialMemDump(unsigned char *start, int n);
+
+
 /* Segmentation is a problem here...
  *
  * When we get a memory operand, presumably we use the default segment (which is?) 
@@ -17,235 +21,464 @@ int handle_cr0_write(struct guest_info * info) {
   char instr[15];
   
   
-  if (info->cpu_mode == REAL) {
-    int index = 0;
-    int ret;
+  switch (info->cpu_mode) { 
+  case REAL: 
+    {
+      int index = 0;
+      int ret;
+      
+      PrintDebug("Real Mode write to CR0 at linear guest pa 0x%x\n",get_addr_linear(info,info->rip,&(info->segments.cs)));
 
-    // The real rip address is actually a combination of the rip + CS base 
-    ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
-    if (ret != 15) {
-      // I think we should inject a GPF into the guest
-      PrintDebug("Could not read instruction (ret=%d)\n", ret);
-      return -1;
-    }
+      PrintV3Segments(info);
 
-    while (is_prefix_byte(instr[index])) {
-      index++; 
-    }
+      // The real rip address is actually a combination of the rip + CS base 
+      ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
+      if (ret != 15) {
+       // I think we should inject a GPF into the guest
+       PrintDebug("Could not read instruction (ret=%d)\n", ret);
+       return -1;
+      }
 
-    if ((instr[index] == cr_access_byte) && 
-       (instr[index + 1] == lmsw_byte) && 
-       (MODRM_REG(instr[index + 2]) == lmsw_reg_byte)) {
+      while (is_prefix_byte(instr[index])) {
+       switch(instr[index]) {
+       case PREFIX_CS_OVERRIDE:
+       case PREFIX_SS_OVERRIDE:
+       case PREFIX_DS_OVERRIDE:
+       case PREFIX_ES_OVERRIDE:
+       case PREFIX_FS_OVERRIDE:
+       case PREFIX_GS_OVERRIDE:
+         PrintDebug("Segment Override!!\n");
+         return -1;
+         break;
+       default:
+         break;
+       }
+       index++; 
+      }
+
+      if ((instr[index] == cr_access_byte) && 
+         (instr[index + 1] == lmsw_byte) && 
+         (MODRM_REG(instr[index + 2]) == lmsw_reg_byte)) {
  
-      addr_t first_operand;
-      addr_t second_operand;
-      struct cr0_real *real_cr0;
-      struct cr0_real *new_cr0;
-      operand_type_t addr_type;
-      char new_cr0_val = 0;
-      // LMSW
-      // decode mod/RM
-      index += 2;
+       addr_t first_operand;
+       addr_t second_operand;
+       struct cr0_real *real_cr0;
+       struct cr0_real *new_cr0;
+       operand_type_t addr_type;
+       char new_cr0_val = 0;
+       // LMSW
+       // decode mod/RM
+       index += 2;
  
-      real_cr0 = (struct cr0_real*)&(info->ctrl_regs.cr0);
+       real_cr0 = (struct cr0_real*)&(info->ctrl_regs.cr0);
 
-      addr_type = decode_operands16(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG16);
+       addr_type = decode_operands16(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG16);
 
 
-      if (addr_type == REG_OPERAND) {
-       new_cr0 = (struct cr0_real *)first_operand;
-      } else if (addr_type == MEM_OPERAND) {
-       addr_t host_addr;
+       if (addr_type == REG_OPERAND) {
+         new_cr0 = (struct cr0_real *)first_operand;
+       } else if (addr_type == MEM_OPERAND) {
+         addr_t host_addr;
 
-       if (guest_pa_to_host_va(info, first_operand + (info->segments.ds.base << 4), &host_addr) == -1) {
-         // gpf the guest
+         if (guest_pa_to_host_va(info, first_operand + (info->segments.ds.base << 4), &host_addr) == -1) {
+           // gpf the guest
+           return -1;
+         }
+
+         new_cr0 = (struct cr0_real *)host_addr;
+       } else {
+
+         // error... don't know what to do
          return -1;
        }
-
-       new_cr0 = (struct cr0_real *)host_addr;
-      } else {
-       // error... don't know what to do
-       return -1;
-      }
                 
-      if ((new_cr0->pe == 1) && (real_cr0->pe == 0)) {
-       info->cpu_mode = PROTECTED;
-      } else if ((new_cr0->pe == 0) && (real_cr0->pe == 1)) {
-       info->cpu_mode = REAL;
-      }
+       if ((new_cr0->pe == 1) && (real_cr0->pe == 0)) {
+         info->cpu_mode = PROTECTED;
+       } else if ((new_cr0->pe == 0) && (real_cr0->pe == 1)) {
+         info->cpu_mode = REAL;
+       }
       
-      new_cr0_val = *(char*)(new_cr0) & 0x0f;
+       new_cr0_val = (*(char*)(new_cr0)) & 0x0f;
 
 
-      if (info->page_mode == SHADOW_PAGING) {
-       struct cr0_real * shadow_cr0 = (struct cr0_real*)&(info->shdw_pg_state.guest_cr0);
+       if (info->shdw_pg_mode == SHADOW_PAGING) {
+         struct cr0_real * shadow_cr0 = (struct cr0_real*)&(info->shdw_pg_state.guest_cr0);
 
-       PrintDebug("Old CR0=%x, Old Shadow CR0=%x\n", *real_cr0, *shadow_cr0);  
-       /* struct cr0_real is only 4 bits wide, 
-        * so we can overwrite the real_cr0 without worrying about the shadow fields
-        */
-       *(char*)real_cr0 &= 0xf0;
-       *(char*)real_cr0 |= new_cr0_val;
+         PrintDebug("Old CR0=%x, Old Shadow CR0=%x\n", *real_cr0, *shadow_cr0);        
+         /* struct cr0_real is only 4 bits wide, 
+          * so we can overwrite the real_cr0 without worrying about the shadow fields
+          */
+         *(char*)real_cr0 &= 0xf0;
+         *(char*)real_cr0 |= new_cr0_val;
        
-       *(char*)shadow_cr0 &= 0xf0;
-       *(char*)shadow_cr0 |= new_cr0_val;
+         *(char*)shadow_cr0 &= 0xf0;
+         *(char*)shadow_cr0 |= new_cr0_val;
 
-       PrintDebug("New CR0=%x, New Shadow CR0=%x\n", *real_cr0, *shadow_cr0);  
-      } else {
-       PrintDebug("Old CR0=%x\n", *real_cr0);  
-       // for now we just pass through....
-       *(char*)real_cr0 &= 0xf0;
-       *(char*)real_cr0 |= new_cr0_val;
 
-       PrintDebug("New CR0=%x\n", *real_cr0);  
-      }
+         PrintDebug("New CR0=%x, New Shadow CR0=%x\n", *real_cr0, *shadow_cr0);        
+       } else {
+         PrintDebug("Old CR0=%x\n", *real_cr0);        
+         // for now we just pass through....
+         *(char*)real_cr0 &= 0xf0;
+         *(char*)real_cr0 |= new_cr0_val;
+
+         PrintDebug("New CR0=%x\n", *real_cr0);        
+       }
 
 
-      info->rip += index;
+       info->rip += index;
 
-    } else if ((instr[index] == cr_access_byte) && 
-              (instr[index + 1] == clts_byte)) {
-      // CLTS
-      PrintDebug("CLTS unhandled\n");
-      return -1;
+      } else if ((instr[index] == cr_access_byte) && 
+                (instr[index + 1] == clts_byte)) {
+       // CLTS
+       PrintDebug("CLTS unhandled in CR0 write\n");
+       return -1;
 
-    } else if ((instr[index] == cr_access_byte) && 
-              (instr[index + 1] = mov_to_cr_byte)) {
-      addr_t first_operand;
-      addr_t second_operand;
-      struct cr0_32 *real_cr0;
-      struct cr0_32 *new_cr0;
-      operand_type_t addr_type;
+      } else if ((instr[index] == cr_access_byte) && 
+                (instr[index + 1] = mov_to_cr_byte)) {
+       addr_t first_operand;
+       addr_t second_operand;
+       struct cr0_32 *real_cr0;
+       struct cr0_32 *new_cr0;
+       operand_type_t addr_type;
      
       
-      index += 2;
+       index += 2;
  
-      real_cr0 = (struct cr0_32*)&(info->ctrl_regs.cr0);
+       real_cr0 = (struct cr0_32*)&(info->ctrl_regs.cr0);
 
-      addr_type = decode_operands16(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG32);
+       addr_type = decode_operands16(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG32);
 
-      if (addr_type != REG_OPERAND) {
-       /* Mov to CR0 Can only be a 32 bit register */
-       // FIX ME
-       return -1;
-      }
+       if (addr_type != REG_OPERAND) {
+         PrintDebug("Moving to CR0 from non-register operand in CR0 write\n");
+         /* Mov to CR0 Can only be a 32 bit register */
+         // FIX ME
+         return -1;
+       }
 
-      new_cr0 = (struct cr0_32 *)first_operand;
+       new_cr0 = (struct cr0_32 *)first_operand;
 
-      if (new_cr0->pe == 1) {
-       PrintDebug("Entering Protected Mode\n");
-       info->cpu_mode = PROTECTED;
-      }
+       if (new_cr0->pe == 1) {
+         PrintDebug("Entering Protected Mode\n");
+         info->cpu_mode = PROTECTED;
+       }
 
-      if (new_cr0->pg == 1) {
-       // GPF the guest??
-       return -1;
-      }
+       if (new_cr0->pe == 0) { 
+         PrintDebug("Entering Real Mode\n");
+         info->cpu_mode = REAL;
+       }
+         
+
+
+       if ((new_cr0->pg == 1) && (new_cr0->pe == 1)) {
+         PrintDebug("Paging is already turned on in switch to protected mode in CR0 write\n");
+
+         // Actually This appears to be Ok. 
+         // Why shouldn't windows be allowed to switch to real mode whenever it wants to modify its page tables?
+
+         info->mem_mode = VIRTUAL_MEM;
+
+         // GPF the guest??
+         //  return -1;
+       } else if ((new_cr0->pg == 1) && (new_cr0->pe == 0)) {
+         PrintDebug("Will the madness Never End??\n");
+         return -1;
+       }
+       
 
-      if (info->page_mode == SHADOW_PAGING) {
-       struct cr0_32 * shadow_cr0 = (struct cr0_32 *)&(info->shdw_pg_state.guest_cr0);
+       if (info->shdw_pg_mode == SHADOW_PAGING) {
+         struct cr0_32 * shadow_cr0 = (struct cr0_32 *)&(info->shdw_pg_state.guest_cr0);
        
-       PrintDebug("Old CR0=%x, Old Shadow CR0=%x\n", *real_cr0, *shadow_cr0);  
-       *real_cr0 = *new_cr0;
-       real_cr0->pg = 1;
+         PrintDebug("Old CR0=%x, Old Shadow CR0=%x\n", *real_cr0, *shadow_cr0);        
+         *real_cr0 = *new_cr0;
+         real_cr0->pg = 1;
+         real_cr0->et = 1;
+
+         *shadow_cr0 = *new_cr0;
+         shadow_cr0->et = 1;
 
-       *shadow_cr0 = *new_cr0;
+         // Setup the page tables...???
+         if (info->mem_mode == VIRTUAL_MEM) {
+           // If we aren't in paged mode then we have to preserve the identity mapped CR3
+           info->ctrl_regs.cr3 = *(addr_t*)&(info->shdw_pg_state.shadow_cr3);
+         }
+
+         PrintDebug("New CR0=%x, New Shadow CR0=%x\n", *real_cr0, *shadow_cr0);        
+       } else {
+         PrintDebug("Old CR0=%x\n", *real_cr0);        
+         *real_cr0 = *new_cr0;
+         PrintDebug("New CR0=%x\n", *real_cr0);        
+       }
+
+       info->rip += index;
 
-       PrintDebug("New CR0=%x, New Shadow CR0=%x\n", *real_cr0, *shadow_cr0);  
       } else {
-       PrintDebug("Old CR0=%x\n", *real_cr0);  
-       *real_cr0 = *new_cr0;
-       PrintDebug("New CR0=%x\n", *real_cr0);  
+       PrintDebug("Unsupported Instruction\n");
+       // unsupported instruction, UD the guest
+       return -1;
       }
 
-      info->rip += index;
+    } 
+    break;
+  case PROTECTED: 
+    {
+
+      int index = 0;
+      int ret;
+
+      PrintDebug("Protected %s Mode write to CR0 at guest %s linear rip 0x%x\n", 
+                info->mem_mode == VIRTUAL_MEM ? "Paged" : "",
+                info->mem_mode == VIRTUAL_MEM ? "virtual" : "",
+                get_addr_linear(info, info->rip, &(info->segments.cs)));
+
+      // OK, now we will read the instruction
+      // The only difference between PROTECTED and PROTECTED_PG is whether we read
+      // from guest_pa or guest_va
+      if (info->mem_mode == PHYSICAL_MEM) { 
+       // The real rip address is actually a combination of the rip + CS base 
+       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);
+      }
+       
 
-    } else {
-      PrintDebug("Unsupported Instruction\n");
-      // unsupported instruction, UD the guest
-      return -1;
-    }
+      if (ret != 15) {
+       // I think we should inject a GPF into the guest
+       PrintDebug("Could not read instruction (ret=%d)\n", ret);
+       return -1;
+      }
 
 
-  } else if (info->cpu_mode == PROTECTED) {
-    int index = 0;
-    int ret;
+      while (is_prefix_byte(instr[index])) {
+       switch(instr[index]) {
+       case PREFIX_CS_OVERRIDE:
+       case PREFIX_SS_OVERRIDE:
+       case PREFIX_DS_OVERRIDE:
+       case PREFIX_ES_OVERRIDE:
+       case PREFIX_FS_OVERRIDE:
+       case PREFIX_GS_OVERRIDE:
+         PrintDebug("Segment Override!!\n");
+         return -1;
+         break;
+       default:
+         break;
+       }
+       index++; 
+      }
 
-    PrintDebug("Protected Mode write to CR0\n");
+      /*
+       while (is_prefix_byte(instr[index])) {
+       index++; 
+       }
+      */
 
-    // The real rip address is actually a combination of the rip + CS base 
-    ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
-    if (ret != 15) {
-      // I think we should inject a GPF into the guest
-      PrintDebug("Could not read instruction (ret=%d)\n", ret);
-      return -1;
-    }
+      struct cr0_32 * shadow_cr0 = (struct cr0_32 *)&(info->shdw_pg_state.guest_cr0);
 
-    while (is_prefix_byte(instr[index])) {
-      index++; 
-    }
+      struct cr0_32 * real_cr0 = (struct cr0_32*)&(info->ctrl_regs.cr0);
 
-    if ((instr[index] == cr_access_byte) && 
-       (instr[index + 1] == mov_to_cr_byte)) {
+      if ((instr[index] == cr_access_byte) && 
+         (instr[index + 1] == mov_to_cr_byte)) {
+
+       // MOV to CR0
     
-      addr_t first_operand;
-      addr_t second_operand;
-      struct cr0_32 *real_cr0;
-      struct cr0_32 *new_cr0;
-      operand_type_t addr_type;
+       addr_t first_operand;
+       addr_t second_operand;
+       struct cr0_32 *new_cr0;
+       operand_type_t addr_type;
 
-      index += 2;
+       index += 2;
  
-      real_cr0 = (struct cr0_32*)&(info->ctrl_regs.cr0);
+       PrintDebug("MovToCR0 instr:\n");
+       PrintTraceMemDump(instr, 15);
+       PrintDebug("EAX=%x\n", *(uint_t*)&(info->vm_regs.rax));
 
-      addr_type = decode_operands32(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG32);
+       addr_type = decode_operands32(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG32);
 
-      if (addr_type != REG_OPERAND) {
-       return -1;
-      }
+       if (addr_type != REG_OPERAND) {
+         PrintDebug("Non-register operand in write to CR0\n");
+         return -1;
+       }
+
+       new_cr0 = (struct cr0_32 *)first_operand;
 
-      new_cr0 = (struct cr0_32 *)first_operand;
+       PrintDebug("first operand=%x\n", *(uint_t *)first_operand);
 
+       if (info->shdw_pg_mode == SHADOW_PAGING) {
+         struct cr0_32 * shadow_cr0 = (struct cr0_32 *)&(info->shdw_pg_state.guest_cr0);
 
-      if (info->page_mode == SHADOW_PAGING) {
-       struct cr0_32 * shadow_cr0 = (struct cr0_32 *)&(info->shdw_pg_state.guest_cr0);
+         if (new_cr0->pg == 1){
+           // This should be new_cr0->pg && !(old_cr->pg), right?
+           // and then a case for turning paging off?
 
-       if (new_cr0->pg == 1){
-         struct cr3_32 * shadow_cr3 = (struct cr3_32 *)&(info->shdw_pg_state.shadow_cr3);
+           struct cr3_32 * shadow_cr3 = (struct cr3_32 *)&(info->shdw_pg_state.shadow_cr3);
 
-         info->cpu_mode = PROTECTED_PG;
+           info->mem_mode = VIRTUAL_MEM;
          
-         *shadow_cr0 = *new_cr0;
-         *real_cr0 = *new_cr0;
+           *shadow_cr0 = *new_cr0;
+           *real_cr0 = *new_cr0;
+           shadow_cr0->et = 1;
+           real_cr0->et = 1;
 
-         //
-         // Activate Shadow Paging
-         //
-         PrintDebug("Turning on paging in the guest\n");
+           //
+           // Activate Shadow Paging
+           //
+           PrintDebug("Turning on paging in the guest\n");
 
-         info->ctrl_regs.cr3 = *(addr_t*)shadow_cr3;
+           info->ctrl_regs.cr3 = *(addr_t*)shadow_cr3;
          
 
-       } else if (new_cr0->pe == 0) {
-         info->cpu_mode = REAL;
+         } else if (new_cr0->pe == 0) {
+           info->cpu_mode = REAL;
+           info->mem_mode = PHYSICAL_MEM;
+           PrintDebug("Entering Real Mode\n");
+
+           PrintV3CtrlRegs(info);
+           // reinstate the identity mapped paged tables
+           // But keep the shadow tables around to handle TLB issues.... UGH...
+           //info->shdw_pg_state.shadow_cr3 &= 0x00000fff;
+           //info->shdw_pg_state.shadow_cr3 |= ((addr_t)create_passthrough_pde32_pts(info) & ~0xfff);
+
+           //info->ctrl_regs.cr3 = info->shdw_pg_state.shadow_cr3;
+           info->ctrl_regs.cr3 = *(addr_t*)&(info->direct_map_pt);
+
+           *shadow_cr0 = *new_cr0;
+           *real_cr0 = *new_cr0;
+           real_cr0->pg = 1;
+           shadow_cr0->et = 1;
+           real_cr0->et = 1;
+
+           PrintV3CtrlRegs(info);
+
+         }
+
+
+       } else {
+         if (new_cr0->pg == 1) {
+           info->mem_mode = VIRTUAL_MEM;
+         } else if (new_cr0->pg == 0) {
+           info->cpu_mode = REAL;
+           info->mem_mode = PHYSICAL_MEM;
+         }
 
-         *shadow_cr0 = *new_cr0;
          *real_cr0 = *new_cr0;
-         real_cr0->pg = 1;
        }
 
+       info->rip += index;
+      } else if ((instr[index] == cr_access_byte) &&
+                (instr[index + 1] == lmsw_byte) &&
+                (MODRM_REG(instr[index + 2]) == lmsw_reg_byte)) {
+       addr_t first_operand;
+       addr_t second_operand;
+       struct cr0_real *real_cr0;
+       struct cr0_real *new_cr0;
+       operand_type_t addr_type;
+       char new_cr0_val = 0;
+
+       index += 2;
+
+       real_cr0 = (struct cr0_real*)&(info->ctrl_regs.cr0);
+
+       addr_type = decode_operands16(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG16);
+
+       if (addr_type == REG_OPERAND) {
+         new_cr0 = (struct cr0_real *)first_operand;
+       } else if (addr_type == MEM_OPERAND) {
+         addr_t host_addr;
+         // check segment descriptors....
+
+         /* TODO, TODO, TODO: Lookup segment overrides */
+         struct v3_segment *lmsw_segment = &(info->segments.ds);
+
+         if (info->mem_mode == PHYSICAL_MEM) {
+           if (guest_pa_to_host_va(info, get_addr_linear(info, first_operand, lmsw_segment), &host_addr) == -1) {
+             return -1;
+           }
+         } else {
+           if (guest_va_to_host_va(info, get_addr_linear(info, first_operand, lmsw_segment), &host_addr) == -1) {
+             return -1;
+           }
+         }
+
+         new_cr0 = (struct cr0_real *)host_addr;
+       } else {
+         return -1;
+       }
+
+       
+       if (new_cr0->pe == 0) {
+         // According to the intel manual this it is illegal to use 
+         // lmsw to turn _off_ Protected mode
+         PrintDebug("Cannot switch to real mode with LMSW, unclear what to do\n");
+         return -1;
+       }
+
+       new_cr0_val = (*(char *)(new_cr0)) & 0x0f;
+
+
+       if (info->shdw_pg_mode == SHADOW_PAGING) {
+         struct cr0_real * shadow_cr0 = (struct cr0_real*)&(info->shdw_pg_state.guest_cr0);
+
+         PrintDebug("Old CR0=%x, Old Shadow CR0=%x\n", *real_cr0, *shadow_cr0);        
+         /* struct cr0_real is only 4 bits wide, 
+          * so we can overwrite the real_cr0 without worrying about the shadow fields
+          */
+         *(char*)real_cr0 &= 0xf0;
+         *(char*)real_cr0 |= new_cr0_val;
+       
+         *(char*)shadow_cr0 &= 0xf0;
+         *(char*)shadow_cr0 |= new_cr0_val;
+
+
+         PrintDebug("New CR0=%x, New Shadow CR0=%x\n", *real_cr0, *shadow_cr0);
+       } else {
+         PrintDebug("Old CR0=%x\n", *real_cr0);        
+         // for now we just pass through....
+         *(char*)real_cr0 &= 0xf0;
+         *(char*)real_cr0 |= new_cr0_val;
+
+         PrintDebug("New CR0=%x\n", *real_cr0);
+       }
+
+       info->rip += index;
+
+
+      } else if ((instr[index] == 0x0f) &&
+                (instr[index + 1] == 0x06)) { 
+       // CLTS instruction
+       PrintDebug("CLTS instruction - clearing TS flag of real and shadow CR0\n");
+       shadow_cr0->ts = 0;
+       real_cr0->ts = 0;
+       
+       index+=2;
+       
+       info->rip+=index;
 
       } else {
-       *real_cr0 = *new_cr0;
+       PrintDebug("Unkown instruction: \n");
+       SerialMemDump(instr,15);
+       return -1;
       }
-
-      info->rip += index;
     }
+    break;
     
-  } else { 
-    PrintDebug("Unknown Mode write to CR0\n");
+  case PROTECTED_PAE:
+    PrintDebug("Protected PAE Mode write to CR0 is UNIMPLEMENTED\n");
+    return -1;
+
+  case LONG:
+    PrintDebug("Protected Long Mode write to CR0 is UNIMPLEMENTED\n");
     return -1;
+
+  default: 
+    {
+      PrintDebug("Unknown Mode write to CR0 (info->cpu_mode=0x%x\n)",info->cpu_mode);
+      return -1;
+    }
+    break;
+
   }
+
   return 0;
 }
 
@@ -253,177 +486,426 @@ int handle_cr0_write(struct guest_info * info) {
 int handle_cr0_read(struct guest_info * info) {
   char instr[15];
 
-  if (info->cpu_mode == REAL) {
-    int index = 0;
-    int ret;
+  switch (info->cpu_mode) { 
 
-    // The real rip address is actually a combination of the rip + CS base 
-    ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
-    if (ret != 15) {
-      // I think we should inject a GPF into the guest
-      PrintDebug("Could not read Real Mode instruction (ret=%d)\n", ret);
-      return -1;
-    }
+  case REAL: 
+    {
 
+      int index = 0;
+      int ret;
 
-    while (is_prefix_byte(instr[index])) {
-      index++; 
-    }
+      PrintDebug("Real Mode read from CR0 at linear guest pa 0x%x\n",get_addr_linear(info,info->rip,&(info->segments.cs)));
+      PrintV3Segments(info);
 
-    if ((instr[index] == cr_access_byte) && 
-       (instr[index + 1] == smsw_byte) && 
-       (MODRM_REG(instr[index + 2]) == smsw_reg_byte)) {
+      // The real rip address is actually a combination of the rip + CS base 
+      ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
+      if (ret != 15) {
+       // I think we should inject a GPF into the guest
+       PrintDebug("Could not read Real Mode instruction (ret=%d)\n", ret);
+       return -1;
+      }
 
-      addr_t first_operand;
-      addr_t second_operand;
-      struct cr0_real *cr0;
-      operand_type_t addr_type;
-      char cr0_val = 0;
 
-      index += 2;
+      while (is_prefix_byte(instr[index])) {
+       switch(instr[index]) {
+       case PREFIX_CS_OVERRIDE:
+       case PREFIX_SS_OVERRIDE:
+       case PREFIX_DS_OVERRIDE:
+       case PREFIX_ES_OVERRIDE:
+       case PREFIX_FS_OVERRIDE:
+       case PREFIX_GS_OVERRIDE:
+         PrintDebug("Segment Override!!\n");
+         return -1;
+         break;
+       default:
+         break;
+       }
+       index++; 
+      }
+
+      /*
+       while (is_prefix_byte(instr[index])) {
+       index++; 
+       }
+      */
+
+      if ((instr[index] == cr_access_byte) && 
+         (instr[index + 1] == smsw_byte) && 
+         (MODRM_REG(instr[index + 2]) == smsw_reg_byte)) {
+
+       // SMSW (store machine status word)
+
+       addr_t first_operand;
+       addr_t second_operand;
+       struct cr0_real *cr0;
+       operand_type_t addr_type;
+       char cr0_val = 0;
+
+       index += 2;
       
-      cr0 = (struct cr0_real*)&(info->ctrl_regs.cr0);
+       cr0 = (struct cr0_real*)&(info->ctrl_regs.cr0);
       
       
-      addr_type = decode_operands16(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG16);
+       addr_type = decode_operands16(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG16);
       
-      if (addr_type == MEM_OPERAND) {
-       addr_t host_addr;
+       if (addr_type == MEM_OPERAND) {
+         addr_t host_addr;
+       
+         if (guest_pa_to_host_va(info, first_operand + (info->segments.ds.base << 4), &host_addr) == -1) {
+           // gpf the guest
+           PrintDebug("Could not convert guest physical address to host virtual address\n");
+           return -1;
+         }
        
-       if (guest_pa_to_host_va(info, first_operand + (info->segments.ds.base << 4), &host_addr) == -1) {
-         // gpf the guest
-         PrintDebug("Could not convert guest physical address to host virtual address\n");
+         first_operand = host_addr;
+       } else {
+         // Register operand
+         // Should be ok??
+       }
+
+       cr0_val = *(char*)cr0 & 0x0f;
+
+       *(char *)first_operand &= 0xf0;
+       *(char *)first_operand |= cr0_val;
+
+       PrintDebug("index = %d, rip = %x\n", index, (ulong_t)(info->rip));
+       info->rip += index;
+       PrintDebug("new_rip = %x\n", (ulong_t)(info->rip));
+       // success
+
+      } else if ((instr[index] == cr_access_byte) &&
+                (instr[index+1] == mov_from_cr_byte)) {
+       /* Mov from CR0
+        * This can only take a 32 bit register argument in anything less than 64 bit mode.
+        */
+       addr_t first_operand;
+       addr_t second_operand;
+       operand_type_t addr_type;
+
+       struct cr0_32 * real_cr0 = (struct cr0_32 *)&(info->ctrl_regs.cr0);
+
+       index += 2;
+
+       addr_type = decode_operands16(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG32);
+     
+       struct cr0_32 * virt_cr0 = (struct cr0_32 *)first_operand;
+  
+       if (addr_type != REG_OPERAND) {
+         // invalid opcode to guest
+         PrintDebug("Invalid operand type in mov from CR0\n");
          return -1;
        }
-       
-       first_operand = host_addr;
+
+       if (info->shdw_pg_mode == SHADOW_PAGING) {
+         *virt_cr0 = *(struct cr0_32 *)&(info->shdw_pg_state.guest_cr0);
+       } else {
+         *virt_cr0 = *real_cr0;
+       }
+
+       info->rip += index;
+
       } else {
-       // Register operand
-       // Should be ok??
+       PrintDebug("Unknown read instr from CR0\n");
+       return -1;
       }
 
-      cr0_val = *(char*)cr0 & 0x0f;
+    } 
 
-      *(char *)first_operand &= 0xf0;
-      *(char *)first_operand |= cr0_val;
+    break;
 
-      PrintDebug("index = %d, rip = %x\n", index, (ulong_t)(info->rip));
-      info->rip += index;
-      PrintDebug("new_rip = %x\n", (ulong_t)(info->rip));
-    } else if ((instr[index] == cr_access_byte) &&
-              (instr[index+1] == mov_from_cr_byte)) {
-      /* Mov from CR0
-       * This can only take a 32 bit register argument in anything less than 64 bit mode.
-       */
-      addr_t first_operand;
-      addr_t second_operand;
-      operand_type_t addr_type;
+  case PROTECTED:
+    {
+    
+      int index = 0;
+      int ret;
+
+      PrintDebug("Protected %s Mode read from CR0 at guest %s linear rip 0x%x\n", 
+                info->mem_mode == VIRTUAL_MEM ? "Paged" : "",
+                info->mem_mode == VIRTUAL_MEM ? "virtual" : "",
+                get_addr_linear(info, info->rip, &(info->segments.cs)));
+
+      // We need to read the instruction, which is at CS:IP, but that 
+      // linear address is guest physical without PG and guest virtual with PG
+      if (info->cpu_mode == PHYSICAL_MEM) { 
+       // The real rip address is actually a combination of the rip + CS base 
+       ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
+      } else { 
+       // The real rip address is actually a combination of the rip + CS base 
+       ret = read_guest_va_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
+      }
 
-      struct cr0_32 * real_cr0 = (struct cr0_32 *)&(info->ctrl_regs.cr0);
 
-      index += 2;
+      PrintDebug("Instr (15 bytes) at %x:\n", instr);
+      PrintTraceMemDump((char*)instr, 15);
 
-      addr_type = decode_operands16(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG32);
-     
-      struct cr0_32 * virt_cr0 = (struct cr0_32 *)first_operand;
-  
-      if (addr_type != REG_OPERAND) {
-       // invalid opcode to guest
-       PrintDebug("Invalid operand type in mov from CR0\n");
+      if (ret != 15) {
+       // I think we should inject a GPF into the guest
+       PrintDebug("Could not read Protected %s mode instruction (ret=%d)\n", 
+                  info->cpu_mode == VIRTUAL_MEM ? "Paged" : "", ret);
        return -1;
       }
 
-      if (info->page_mode == SHADOW_PAGING) {
-       *virt_cr0 = *(struct cr0_32 *)&(info->shdw_pg_state.guest_cr0);
-      } else {
-       *virt_cr0 = *real_cr0;
+
+      while (is_prefix_byte(instr[index])) {
+       switch(instr[index]) {
+       case PREFIX_CS_OVERRIDE:
+       case PREFIX_SS_OVERRIDE:
+       case PREFIX_DS_OVERRIDE:
+       case PREFIX_ES_OVERRIDE:
+       case PREFIX_FS_OVERRIDE:
+       case PREFIX_GS_OVERRIDE:
+         PrintDebug("Segment Override!!\n");
+         return -1;
+         break;
+       default:
+         break;
+       }
+       index++; 
       }
 
-      info->rip += index;
 
-    } else {
-      PrintDebug("Unknown read instr from CR0\n");
+      /*
+       while (is_prefix_byte(instr[index])) {
+       index++; 
+       }
+      */
+
+      if ((instr[index] == cr_access_byte) &&
+         (instr[index+1] == mov_from_cr_byte)) {
+       
+       // MOV from CR0 to register
+
+       addr_t first_operand;
+       addr_t second_operand;
+       operand_type_t addr_type;
+       struct cr0_32 * virt_cr0;
+       struct cr0_32 * real_cr0 = (struct cr0_32 *)&(info->ctrl_regs.cr0);
+
+       index += 2;
+
+       addr_type = decode_operands32(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG32);
+
+       if (addr_type != REG_OPERAND) {
+         PrintDebug("Invalid operand type in mov from CR0\n");
+         return -1;
+       }
+      
+       virt_cr0 = (struct cr0_32 *)first_operand;
+
+       if (info->shdw_pg_mode == SHADOW_PAGING) {
+         *virt_cr0 = *(struct cr0_32 *)&(info->shdw_pg_state.guest_cr0);
+         
+         if (info->mem_mode == PHYSICAL_MEM) {
+           virt_cr0->pg = 0; // clear the pg bit because guest doesn't think it's on
+         }
+         
+       } else {
+         *virt_cr0 = *real_cr0;
+       }
+
+         PrintDebug("real CR0: %x\n", *(uint_t*)real_cr0);
+         PrintDebug("returned CR0: %x\n", *(uint_t*)virt_cr0);
+      
+       info->rip += index;
+
+      } else { 
+       PrintDebug("Unknown read instruction from CR0\n");
+       return -1;
+      }
+    }
+    break;
+
+  case PROTECTED_PAE:
+    PrintDebug("Protected PAE Mode read to CR0 is UNIMPLEMENTED\n");
+    return -1;
+
+  case LONG:
+    PrintDebug("Protected Long Mode read to CR0 is UNIMPLEMENTED\n");
+    return -1;
+
+
+  default:
+    {
+      PrintDebug("Unknown Mode read from CR0 (info->cpu_mode=0x%x)\n",info->cpu_mode);
       return -1;
     }
+    break;
+  }
+
+
+  return 0;
+}
+
+
+
+
+int handle_cr3_write(struct guest_info * info) {
+  if (info->cpu_mode == REAL) {
+    // WHAT THE HELL DOES THIS EVEN MEAN?????
 
-  } else if (info->cpu_mode == PROTECTED) {
     int index = 0;
     int ret;
+    char instr[15];
+
+    PrintDebug("Real Mode Write to CR3??? What the fuck???\n");
+    // We need to read the instruction, which is at CS:IP, but that 
+    // linear address is guest physical without PG and guest virtual with PG
 
-    // The real rip address is actually a combination of the rip + CS base 
     ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
+
     if (ret != 15) {
-      // I think we should inject a GPF into the guest
-      PrintDebug("Could not read Proteced mode instruction (ret=%d)\n", ret);
+      PrintDebug("Could not read instruction (ret=%d)\n", ret);
       return -1;
     }
 
     while (is_prefix_byte(instr[index])) {
+      switch(instr[index]) {
+      case PREFIX_CS_OVERRIDE:
+      case PREFIX_SS_OVERRIDE:
+      case PREFIX_DS_OVERRIDE:
+      case PREFIX_ES_OVERRIDE:
+      case PREFIX_FS_OVERRIDE:
+      case PREFIX_GS_OVERRIDE:
+       PrintDebug("Segment Override!!\n");
+       return -1;
+       break;
+      default:
+       break;
+      }
       index++; 
     }
+    
 
+    if ((instr[index] == cr_access_byte) && 
+       (instr[index + 1] == mov_to_cr_byte)) {
 
-    if ((instr[index] == cr_access_byte) &&
-       (instr[index+1] == mov_from_cr_byte)) {
       addr_t first_operand;
       addr_t second_operand;
+      struct cr3_32 * new_cr3;
+      //      struct cr3_32 * real_cr3;
       operand_type_t addr_type;
-      struct cr0_32 * virt_cr0;
-      struct cr0_32 * real_cr0 = (struct cr0_32 *)&(info->ctrl_regs.cr0);
 
       index += 2;
 
-      addr_type = decode_operands32(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG32);
+      addr_type = decode_operands16(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG32);
 
       if (addr_type != REG_OPERAND) {
-       PrintDebug("Invalid operand type in mov from CR0\n");
+       /* Mov to CR3 can only be a 32 bit register */
        return -1;
       }
-      
-      virt_cr0 = (struct cr0_32 *)first_operand;
 
-      if (info->page_mode == SHADOW_PAGING) {
-       *virt_cr0 = *(struct cr0_32 *)&(info->shdw_pg_state.guest_cr0);
-      } else {
-       *virt_cr0 = *real_cr0;
-      }
-      
-      info->rip += index;
+      new_cr3 = (struct cr3_32 *)first_operand;
 
-    } else { 
-      PrintDebug("Unknown read instruction from CR0\n");
-      return -1;
-    }
+      if (info->shdw_pg_mode == SHADOW_PAGING) {
+       addr_t shadow_pt;
+       struct cr3_32 * shadow_cr3 = (struct cr3_32 *)&(info->shdw_pg_state.shadow_cr3);
+       struct cr3_32 * guest_cr3 = (struct cr3_32 *)&(info->shdw_pg_state.guest_cr3);
 
-  } else {
-    PrintDebug("Unknown mode read from CR0\n");
-    return -1;
-  }
+       /*
 
+         if (CR3_TO_PDE32(*(uint_t*)shadow_cr3) != 0) {
+           PrintDebug("Shadow Page Table\n");
+           PrintDebugPageTables((pde32_t *)CR3_TO_PDE32(*(uint_t*)shadow_cr3));
+         }
+       */
 
-  return 0;
-}
+       /* Delete the current Page Tables */
+       delete_page_tables_pde32((pde32_t *)CR3_TO_PDE32(*(uint_t*)shadow_cr3));
 
+       PrintDebug("Old Shadow CR3=%x; Old Guest CR3=%x\n", 
+                  *(uint_t*)shadow_cr3, *(uint_t*)guest_cr3);
 
 
+       *guest_cr3 = *new_cr3;
 
-int handle_cr3_write(struct guest_info * info) {
-  if ((info->cpu_mode == PROTECTED) || (info->cpu_mode == PROTECTED_PG)) {
+
+
+       // Something like this
+       shadow_pt =  create_new_shadow_pt32(info);
+       //shadow_pt = setup_shadow_pt32(info, CR3_TO_PDE32(*(addr_t *)new_cr3));
+
+       /* Copy Various flags */
+       *shadow_cr3 = *new_cr3;
+
+       /*
+       {
+         addr_t tmp_addr;
+         guest_pa_to_host_va(info, ((*(uint_t*)guest_cr3) & 0xfffff000), &tmp_addr);
+         PrintDebug("Guest PD\n");
+         PrintPD32((pde32_t *)tmp_addr);
+
+       }
+       */
+
+       
+       shadow_cr3->pdt_base_addr = PD32_BASE_ADDR(shadow_pt);
+
+       PrintDebug("New Shadow CR3=%x; New Guest CR3=%x\n", 
+                  *(uint_t*)shadow_cr3, *(uint_t*)guest_cr3);
+
+
+
+
+      }
+      info->rip += index;
+
+    } else {
+      PrintDebug("Unknown Instruction\n");
+      SerialMemDump(instr,15);
+      return -1;
+    }
+
+
+
+  } else if (info->cpu_mode == PROTECTED) {
     int index = 0;
     int ret;
     char instr[15];
 
+    PrintDebug("Protected %s mode write to CR3 at %s 0x%x\n",
+              info->cpu_mode==PROTECTED ? "" : "Paged", 
+              info->cpu_mode==PROTECTED ? "guest physical" : "guest virtual",
+              get_addr_linear(info,info->rip,&(info->segments.cs)));
+
+    // We need to read the instruction, which is at CS:IP, but that 
+    // linear address is guest physical without PG and guest virtual with PG
+    if (info->mem_mode == PHYSICAL_MEM) { 
+      // The real rip address is actually a combination of the rip + CS base 
+      PrintDebug("Writing Guest CR3 Write (Physical Address)\n");
+      ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
+    } else { 
+      PrintDebug("Writing Guest CR3 Write (Virtual Address)\n");
+      // The real rip address is actually a combination of the rip + CS base 
+      ret = read_guest_va_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
+    }
 
-    /* Isn't the RIP a Guest Virtual Address???????? */
-    ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
     if (ret != 15) {
       PrintDebug("Could not read instruction (ret=%d)\n", ret);
       return -1;
     }
-    
+
     while (is_prefix_byte(instr[index])) {
-      index++;
+      switch(instr[index]) {
+      case PREFIX_CS_OVERRIDE:
+      case PREFIX_SS_OVERRIDE:
+      case PREFIX_DS_OVERRIDE:
+      case PREFIX_ES_OVERRIDE:
+      case PREFIX_FS_OVERRIDE:
+      case PREFIX_GS_OVERRIDE:
+       PrintDebug("Segment Override!!\n");
+       return -1;
+       break;
+      default:
+       break;
+      }
+      index++; 
     }
+    
+    /*    
+         while (is_prefix_byte(instr[index])) {
+         index++;
+         }
+    */
 
     if ((instr[index] == cr_access_byte) && 
        (instr[index + 1] == mov_to_cr_byte)) {
@@ -445,30 +927,56 @@ int handle_cr3_write(struct guest_info * info) {
 
       new_cr3 = (struct cr3_32 *)first_operand;
 
-      if (info->page_mode == SHADOW_PAGING) {
+      if (info->shdw_pg_mode == SHADOW_PAGING) {
        addr_t shadow_pt;
        struct cr3_32 * shadow_cr3 = (struct cr3_32 *)&(info->shdw_pg_state.shadow_cr3);
        struct cr3_32 * guest_cr3 = (struct cr3_32 *)&(info->shdw_pg_state.guest_cr3);
 
-       PrintDebug("fooo1\n");
+
+       /*
+         if (CR3_TO_PDE32(*(uint_t*)shadow_cr3) != 0) {
+           PrintDebug("Shadow Page Table\n");
+           PrintDebugPageTables((pde32_t *)CR3_TO_PDE32(*(uint_t*)shadow_cr3));
+         }
+       */
 
        /* Delete the current Page Tables */
        delete_page_tables_pde32((pde32_t *)CR3_TO_PDE32(*(uint_t*)shadow_cr3));
 
-       PrintDebug("fooo2\n");
+       PrintDebug("Old Shadow CR3=%x; Old Guest CR3=%x\n", 
+                  *(uint_t*)shadow_cr3, *(uint_t*)guest_cr3);
+
+
        *guest_cr3 = *new_cr3;
 
+
+
        // Something like this
        shadow_pt =  create_new_shadow_pt32(info);
        //shadow_pt = setup_shadow_pt32(info, CR3_TO_PDE32(*(addr_t *)new_cr3));
 
-
        /* Copy Various flags */
        *shadow_cr3 = *new_cr3;
+
+       /*
+       {
+         addr_t tmp_addr;
+         guest_pa_to_host_va(info, ((*(uint_t*)guest_cr3) & 0xfffff000), &tmp_addr);
+         PrintDebug("Guest PD\n");
+         PrintPD32((pde32_t *)tmp_addr);
+
+       }
+       */
+
        
        shadow_cr3->pdt_base_addr = PD32_BASE_ADDR(shadow_pt);
 
-       if (info->cpu_mode == PROTECTED_PG) {
+       PrintDebug("New Shadow CR3=%x; New Guest CR3=%x\n", 
+                  *(uint_t*)shadow_cr3, *(uint_t*)guest_cr3);
+
+
+
+       if (info->mem_mode == VIRTUAL_MEM) {
          // If we aren't in paged mode then we have to preserve the identity mapped CR3
          info->ctrl_regs.cr3 = *(addr_t*)shadow_cr3;
        }
@@ -478,10 +986,11 @@ int handle_cr3_write(struct guest_info * info) {
 
     } else {
       PrintDebug("Unknown Instruction\n");
+      SerialMemDump(instr,15);
       return -1;
     }
   } else {
-    PrintDebug("Invalid operating Mode\n");
+    PrintDebug("Invalid operating Mode (0x%x)\n", info->cpu_mode);
     return -1;
   }
 
@@ -492,21 +1001,123 @@ int handle_cr3_write(struct guest_info * info) {
 
 
 int handle_cr3_read(struct guest_info * info) {
-  if ((info->cpu_mode == PROTECTED) || (info->cpu_mode == PROTECTED_PG)) {
+
+  if (info->cpu_mode == REAL) {
+    char instr[15];
+    int ret;
+    int index = 0;
+    addr_t linear_addr = 0;
+
+    linear_addr = get_addr_linear(info, info->rip, &(info->segments.cs));
+
+    
+    PrintDebug("RIP Linear: %x\n", linear_addr);
+    PrintV3Segments(info);
+    
+    ret = read_guest_pa_memory(info, linear_addr, 15, instr);
+
+    if (ret != 15) {
+      PrintDebug("Could not read instruction (ret=%d)\n", ret);
+      return -1;
+    }
+    
+    while (is_prefix_byte(instr[index])) {
+      switch(instr[index]) {
+      case PREFIX_CS_OVERRIDE:
+      case PREFIX_SS_OVERRIDE:
+      case PREFIX_DS_OVERRIDE:
+      case PREFIX_ES_OVERRIDE:
+      case PREFIX_FS_OVERRIDE:
+      case PREFIX_GS_OVERRIDE:
+       PrintDebug("Segment Override!!\n");
+       return -1;
+       break;
+      default:
+       break;
+      }
+      index++; 
+    }
+
+
+    if ((instr[index] == cr_access_byte) && 
+       (instr[index + 1] == mov_from_cr_byte)) {
+      addr_t first_operand;
+      addr_t second_operand;
+      struct cr3_32 * virt_cr3;
+      struct cr3_32 * real_cr3 = (struct cr3_32 *)&(info->ctrl_regs.cr3);
+      operand_type_t addr_type;
+
+      index += 2;
+
+      addr_type = decode_operands16(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG32);
+
+      if (addr_type != REG_OPERAND) {
+       /* Mov to CR3 can only be a 32 bit register */
+       return -1;
+      }
+
+      virt_cr3 = (struct cr3_32 *)first_operand;
+
+      if (info->shdw_pg_mode == SHADOW_PAGING) {
+       *virt_cr3 = *(struct cr3_32 *)&(info->shdw_pg_state.guest_cr3);
+      } else {
+       *virt_cr3 = *real_cr3;
+      }
+      
+      info->rip += index;
+    } else {
+      PrintDebug("Unknown Instruction\n");
+      SerialMemDump(instr,15);
+      return -1;
+    }
+
+
+    return 0;
+  } else if (info->cpu_mode == PROTECTED) {
+
     int index = 0;
     int ret;
     char instr[15];
 
-    ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
+   
+    // We need to read the instruction, which is at CS:IP, but that 
+    // linear address is guest physical without PG and guest virtual with PG
+    if (info->cpu_mode == PHYSICAL_MEM) { 
+      // The real rip address is actually a combination of the rip + CS base 
+      ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
+    } else { 
+      // The real rip address is actually a combination of the rip + CS base 
+      ret = read_guest_va_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
+    }
+
     if (ret != 15) {
       PrintDebug("Could not read instruction (ret=%d)\n", ret);
       return -1;
     }
     
     while (is_prefix_byte(instr[index])) {
-      index++;
+      switch(instr[index]) {
+      case PREFIX_CS_OVERRIDE:
+      case PREFIX_SS_OVERRIDE:
+      case PREFIX_DS_OVERRIDE:
+      case PREFIX_ES_OVERRIDE:
+      case PREFIX_FS_OVERRIDE:
+      case PREFIX_GS_OVERRIDE:
+       PrintDebug("Segment Override!!\n");
+       return -1;
+       break;
+      default:
+       break;
+      }
+      index++; 
     }
 
+    /*
+      while (is_prefix_byte(instr[index])) {
+      index++;
+      }
+    */
+
     if ((instr[index] == cr_access_byte) && 
        (instr[index + 1] == mov_from_cr_byte)) {
       addr_t first_operand;
@@ -526,7 +1137,7 @@ int handle_cr3_read(struct guest_info * info) {
 
       virt_cr3 = (struct cr3_32 *)first_operand;
 
-      if (info->page_mode == SHADOW_PAGING) {
+      if (info->shdw_pg_mode == SHADOW_PAGING) {
        *virt_cr3 = *(struct cr3_32 *)&(info->shdw_pg_state.guest_cr3);
       } else {
        *virt_cr3 = *real_cr3;
@@ -535,10 +1146,12 @@ int handle_cr3_read(struct guest_info * info) {
       info->rip += index;
     } else {
       PrintDebug("Unknown Instruction\n");
+      SerialMemDump(instr,15);
       return -1;
     }
   } else {
-    PrintDebug("Invalid operating Mode\n");
+    PrintDebug("Invalid operating Mode (0x%x), control registers follow\n", info->cpu_mode);
+    PrintV3CtrlRegs(info);
     return -1;
   }