/* 
 * 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_paging.h>

#include <palacios/vmm.h>

#include <palacios/vm_guest_mem.h>



#define USE_VMM_PAGING_DEBUG
// All of the debug functions defined in vmm_paging.h are implemented in this file
#include "vmm_paging_debug.h"
#undef USE_VMM_PAGING_DEBUG


void delete_page_tables_32(pde32_t * pde) {
  int i;

  if (pde == NULL) { 
    return;
  }

  for (i = 0; (i < MAX_PDE32_ENTRIES); i++) {
    if (pde[i].present) {
      // We double cast, first to an addr_t to handle 64 bit issues, then to the pointer
      PrintDebug("PTE base addr %x \n", pde[i].pt_base_addr);
      pte32_t * pte = (pte32_t *)((addr_t)(uint_t)(pde[i].pt_base_addr << PAGE_POWER));

      PrintDebug("Deleting PTE %d (%p)\n", i, pte);
      V3_FreePage(pte);
    }
  }

  PrintDebug("Deleting PDE (%p)\n", pde);
  V3_FreePage(V3_PAddr(pde));
}

void delete_page_tables_32PAE(pdpe32pae_t * pdpe) { 
  PrintError("Unimplemented function\n");
}

void delete_page_tables_64(pml4e64_t * pml4) {
  PrintError("Unimplemented function\n");
}


int v3_translate_guest_pt_32(struct guest_info * info, addr_t guest_cr3, addr_t vaddr, addr_t * paddr) {
  addr_t guest_pde_pa = CR3_TO_PDE32_PA(guest_cr3);
  pde32_t * guest_pde = 0;
  addr_t guest_pte_pa = 0;

  if (guest_pa_to_host_va(info, guest_pde_pa, (addr_t*)&guest_pde) == -1) {
    PrintError("Could not get virtual address of Guest PDE32 (PA=%p)\n", 
	       (void *)guest_pde_pa);
    return -1;
  }
  
  switch (pde32_lookup(guest_pde, vaddr, &guest_pte_pa)) {
  case PT_ENTRY_NOT_PRESENT:
    *paddr = 0;  
    return -1;
  case PT_ENTRY_LARGE_PAGE:
    *paddr = guest_pte_pa;
    return 0;
  case PT_ENTRY_PAGE:
    {
      pte32_t * guest_pte = NULL;

      if (guest_pa_to_host_va(info, guest_pte_pa, (addr_t*)&guest_pte) == -1) {
	PrintError("Could not get virtual address of Guest PTE32 (PA=%p)\n", 
		   (void *)guest_pte_pa);
	return -1;
      }

      if (pte32_lookup(guest_pte, vaddr, paddr) == PT_ENTRY_NOT_PRESENT) {
	return -1;
      }

      return 0;
    }
  }

  return 0;
}


int v3_translate_guest_pt_32pae(struct guest_info * info, addr_t guest_cr3, addr_t vaddr, addr_t * paddr) {
  addr_t guest_pdpe_pa = CR3_TO_PDPE32PAE_PA(guest_cr3);
  pdpe32pae_t * guest_pdpe = 0;
  addr_t guest_pde_pa = 0;

  if (guest_pa_to_host_va(info, guest_pdpe_pa, (addr_t*)&guest_pdpe) == -1) {
    PrintError("Could not get virtual address of Guest PDPE32PAE (PA=%p)\n",
	       (void *)guest_pdpe_pa);
    return -1;
  }

  switch (pdpe32pae_lookup(guest_pdpe, vaddr, &guest_pde_pa)) 
    {
    case PT_ENTRY_NOT_PRESENT:
      *paddr = 0;
      return -1;
    case PT_ENTRY_PAGE:
      {
	pde32pae_t * guest_pde = NULL;
	addr_t guest_pte_pa = 0;
	
	if (guest_pa_to_host_va(info, guest_pde_pa, (addr_t *)&guest_pde) == -1) {
	  PrintError("Could not get virtual Address of Guest PDE32PAE (PA=%p)\n", 
		     (void *)guest_pde_pa);
	  return -1;
	}
	
	switch (pde32pae_lookup(guest_pde, vaddr, &guest_pte_pa)) 
	  {
	  case PT_ENTRY_NOT_PRESENT:
	    *paddr = 0;
	    return -1;
	  case PT_ENTRY_LARGE_PAGE:
	    *paddr = guest_pte_pa;
	    return 0;
	  case PT_ENTRY_PAGE:
	    {
	      pte32pae_t * guest_pte = NULL;
	      
	      if (guest_pa_to_host_va(info, guest_pte_pa, (addr_t *)&guest_pte) == -1) {
		PrintError("Could not get virtual Address of Guest PTE32PAE (PA=%p)\n", 
			   (void *)guest_pte_pa);
		return -1;
	      }

	      if (pte32pae_lookup(guest_pte, vaddr, paddr) == PT_ENTRY_NOT_PRESENT) {
		return -1;
	      }

	      return 0;
	    }
	  }
      }
    default:
      return -1;
    }

  return 0;
}

int v3_translate_guest_pt_64(struct guest_info * info, addr_t guest_cr3, addr_t vaddr, addr_t * paddr) {
  addr_t guest_pml4_pa = CR3_TO_PML4E64_PA(guest_cr3);
  pml4e64_t * guest_pmle = 0;
  addr_t guest_pdpe_pa = 0;

  if (guest_pa_to_host_va(info, guest_pml4_pa, (addr_t*)&guest_pmle) == -1) {
    PrintError("Could not get virtual address of Guest PML4E64 (PA=%p)\n", 
	       (void *)guest_pml4_pa);
    return -1;
  }
  
  switch (pml4e64_lookup(guest_pmle, vaddr, &guest_pdpe_pa)) {
  case PT_ENTRY_NOT_PRESENT:
    *paddr = 0;
    return -1;
  case PT_ENTRY_PAGE:
    {
      pdpe64_t * guest_pdp = NULL;
      addr_t guest_pde_pa = 0;

      if (guest_pa_to_host_va(info, guest_pdpe_pa, (addr_t *)&guest_pdp) == -1) {
	PrintError("Could not get virtual address of Guest PDPE64 (PA=%p)\n", 
		   (void *)guest_pdpe_pa);
	return -1;
      }

      switch (pdpe64_lookup(guest_pdp, vaddr, &guest_pde_pa)) {
      case PT_ENTRY_NOT_PRESENT:
	*paddr = 0;
	return -1;
      case PT_ENTRY_LARGE_PAGE:
	*paddr = 0;
	PrintError("1 Gigabyte Pages not supported\n");
	return -1;
      case PT_ENTRY_PAGE:
	{
	  pde64_t * guest_pde = NULL;
	  addr_t guest_pte_pa = 0;

	  if (guest_pa_to_host_va(info, guest_pde_pa, (addr_t *)&guest_pde) == -1) {
	    PrintError("Could not get virtual address of guest PDE64 (PA=%p)\n", 
		       (void *)guest_pde_pa);
	    return -1;
	  }

	  switch (pde64_lookup(guest_pde, vaddr, &guest_pte_pa)) {
	  case PT_ENTRY_NOT_PRESENT:
	    *paddr = 0;
	    return -1;
	  case PT_ENTRY_LARGE_PAGE:
	    *paddr = guest_pte_pa;
	    return 0;
	  case PT_ENTRY_PAGE:
	    {
	      pte64_t * guest_pte = NULL;
	      
	      if (guest_pa_to_host_va(info, guest_pte_pa, (addr_t *)&guest_pte) == -1) {
		PrintError("Could not get virtual address of guest PTE64 (PA=%p)\n", 
			   (void *)guest_pte_pa);
		return -1;
	      }
		
	      if (pte64_lookup(guest_pte, vaddr, paddr) == PT_ENTRY_NOT_PRESENT) {
		return -1;
	      }

	      return 0;
	    }
	  }
	}
      }
    }
  default:
    return -1;
  }
  return 0;
}



int v3_translate_host_pt_32(addr_t host_cr3, addr_t vaddr, addr_t * paddr) {
  pde32_t * host_pde = (pde32_t *)CR3_TO_PDE32_VA(host_cr3);
  pte32_t * host_pte = 0;
    
  switch (pde32_lookup(host_pde, vaddr, (addr_t *)&host_pte)) {
  case PT_ENTRY_NOT_PRESENT:
    *paddr = 0;
    return -1;
  case PT_ENTRY_LARGE_PAGE:
    *paddr = (addr_t)host_pte;
    return 0;
  case PT_ENTRY_PAGE:
    if (pte32_lookup(host_pte, vaddr, paddr) == PT_ENTRY_NOT_PRESENT) {
      return -1;
    }
    return 0;
  }
  
  // should never get here
  return -1;
}


int v3_translate_host_pt_32pae(addr_t host_cr3, addr_t vaddr, addr_t * paddr) {
  pdpe32pae_t * host_pdpe = (pdpe32pae_t *)CR3_TO_PDPE32PAE_VA(host_cr3);
  pde32pae_t * host_pde = NULL;
  pte32pae_t * host_pte = NULL;

  switch (pdpe32pae_lookup(host_pdpe, vaddr, (addr_t *)&host_pde)) {
  case PT_ENTRY_NOT_PRESENT:
    *paddr = 0;
    return -1;
  case PT_ENTRY_PAGE:
    switch (pde32pae_lookup(host_pde, vaddr, (addr_t *)&host_pte)) {
    case PT_ENTRY_NOT_PRESENT:
      *paddr = 0;
      return -1;
    case PT_ENTRY_LARGE_PAGE:
      *paddr = (addr_t)host_pte;
      return 0;
    case PT_ENTRY_PAGE:
      if (pte32pae_lookup(host_pte, vaddr, paddr) == PT_ENTRY_NOT_PRESENT) {
	return -1;
      }
      return 0;
    }
  default:
    return -1;
  }

  // should never get here
  return -1;
}


int v3_translate_host_pt_64(addr_t host_cr3, addr_t vaddr, addr_t * paddr) {
  pml4e64_t * host_pmle = (pml4e64_t *)CR3_TO_PML4E64_VA(host_cr3);
  pdpe64_t * host_pdpe = NULL;
  pde64_t * host_pde = NULL;
  pte64_t * host_pte = NULL;

  switch(pml4e64_lookup(host_pmle, vaddr, (addr_t *)&host_pdpe)) {
  case PT_ENTRY_NOT_PRESENT:
    *paddr = 0;
    return -1;
  case PT_ENTRY_PAGE:
    switch(pdpe64_lookup(host_pdpe, vaddr, (addr_t *)&host_pde)) {
    case PT_ENTRY_NOT_PRESENT:
      *paddr = 0;
      return -1;
    case PT_ENTRY_LARGE_PAGE:
      *paddr = 0;
      PrintError("1 Gigabyte Pages not supported\n");
      return -1;
    case PT_ENTRY_PAGE:
      switch (pde64_lookup(host_pde, vaddr, (addr_t *)&host_pte)) {
      case PT_ENTRY_NOT_PRESENT:
	*paddr = 0;
	return -1;
      case PT_ENTRY_LARGE_PAGE:
      case PT_ENTRY_PAGE:
	if (pte64_lookup(host_pte, vaddr, paddr) == PT_ENTRY_NOT_PRESENT) {
	  return -1;
	}
	return 0;
      }
    }
  default:
    return -1;
  }

  // should never get here
  return -1;
}





/*
 * PAGE TABLE LOOKUP FUNCTIONS
 *
 *
 * The value of entry is a return type:
 * Page not present: *entry = 0
 * Large Page: *entry = translated physical address (byte granularity)
 * PTE entry: *entry is the address of the PTE Page
 */

/**
 * 
 *  32 bit Page Table lookup functions
 *
 **/

pt_entry_type_t pde32_lookup(pde32_t * pd, addr_t addr, addr_t * entry) {
  pde32_t * pde_entry = &(pd[PDE32_INDEX(addr)]);

  if (!pde_entry->present) {
    *entry = 0;
    return PT_ENTRY_NOT_PRESENT;
  } else if (pde_entry->large_page) {
    pde32_4MB_t * large_pde = (pde32_4MB_t *)pde_entry;

    *entry = BASE_TO_PAGE_ADDR_4MB(large_pde->page_base_addr);
    *entry += PAGE_OFFSET_4MB(addr);

    return PT_ENTRY_LARGE_PAGE;
  } else {
    *entry = BASE_TO_PAGE_ADDR(pde_entry->pt_base_addr);
    return PT_ENTRY_PAGE;
  }
}



/* Takes a virtual addr (addr) and returns the physical addr (entry) as defined in the page table
 */
pt_entry_type_t pte32_lookup(pte32_t * pt, addr_t addr, addr_t * entry) {
  pte32_t * pte_entry = &(pt[PTE32_INDEX(addr)]);

  if (!pte_entry->present) {
    *entry = 0;
    //    PrintDebug("Lookup at non present page (index=%d)\n", PTE32_INDEX(addr));
    return PT_ENTRY_NOT_PRESENT;
  } else {
    *entry = BASE_TO_PAGE_ADDR(pte_entry->page_base_addr) + PAGE_OFFSET(addr);
    return PT_ENTRY_PAGE;
  }

}



/**
 * 
 *  32 bit PAE Page Table lookup functions
 *
 **/
pt_entry_type_t pdpe32pae_lookup(pdpe32pae_t * pdp, addr_t addr, addr_t * entry) {
  pdpe32pae_t * pdpe_entry = &(pdp[PDPE32PAE_INDEX(addr)]);
  
  if (!pdpe_entry->present) {
    *entry = 0;
    return PT_ENTRY_NOT_PRESENT;
  } else {
    *entry = BASE_TO_PAGE_ADDR(pdpe_entry->pd_base_addr);
    return PT_ENTRY_PAGE;
  }
}

pt_entry_type_t pde32pae_lookup(pde32pae_t * pd, addr_t addr, addr_t * entry) {
  pde32pae_t * pde_entry = &(pd[PDE32PAE_INDEX(addr)]);

  if (!pde_entry->present) {
    *entry = 0;
    return PT_ENTRY_NOT_PRESENT;
  } else if (pde_entry->large_page) {
    pde32pae_2MB_t * large_pde = (pde32pae_2MB_t *)pde_entry;

    *entry = BASE_TO_PAGE_ADDR_2MB(large_pde->page_base_addr);
    *entry += PAGE_OFFSET_2MB(addr);

    return PT_ENTRY_LARGE_PAGE;
  } else {
    *entry = BASE_TO_PAGE_ADDR(pde_entry->pt_base_addr);
    return PT_ENTRY_PAGE;
  }
}

pt_entry_type_t pte32pae_lookup(pte32pae_t * pt, addr_t addr, addr_t * entry) {
  pte32pae_t * pte_entry = &(pt[PTE32PAE_INDEX(addr)]);

  if (!pte_entry->present) {
    *entry = 0;
    return PT_ENTRY_NOT_PRESENT;
  } else {
    *entry = BASE_TO_PAGE_ADDR(pte_entry->page_base_addr) + PAGE_OFFSET(addr);
    return PT_ENTRY_PAGE;
  }
}



/**
 * 
 *  64 bit Page Table lookup functions
 *
 **/
pt_entry_type_t pml4e64_lookup(pml4e64_t * pml, addr_t addr, addr_t * entry) {
  pml4e64_t * pml_entry = &(pml[PML4E64_INDEX(addr)]);

  if (!pml_entry->present) {
    *entry = 0;
    return PT_ENTRY_NOT_PRESENT;
  } else {
    *entry = BASE_TO_PAGE_ADDR(pml_entry->pdp_base_addr);
    return PT_ENTRY_PAGE;
  }
}

pt_entry_type_t pdpe64_lookup(pdpe64_t * pdp, addr_t addr, addr_t * entry) {
  pdpe64_t * pdpe_entry = &(pdp[PDPE64_INDEX(addr)]);
  
  if (!pdpe_entry->present) {
    *entry = 0;
    return PT_ENTRY_NOT_PRESENT;
  } else if (pdpe_entry->large_page) {
    PrintError("1 Gigabyte pages not supported\n");
    V3_ASSERT(0);
    return -1;
  } else {
    *entry = BASE_TO_PAGE_ADDR(pdpe_entry->pd_base_addr);
    return PT_ENTRY_PAGE;
  }
}

pt_entry_type_t pde64_lookup(pde64_t * pd, addr_t addr, addr_t * entry) {
  pde64_t * pde_entry = &(pd[PDE64_INDEX(addr)]);

  if (!pde_entry->present) {
    *entry = 0;
    return PT_ENTRY_NOT_PRESENT;
  } else if (pde_entry->large_page) {
    pde64_2MB_t * large_pde = (pde64_2MB_t *)pde_entry;

    *entry = BASE_TO_PAGE_ADDR_2MB(large_pde->page_base_addr);
    *entry += PAGE_OFFSET_2MB(addr);

    return PT_ENTRY_LARGE_PAGE;
  } else {
    *entry = BASE_TO_PAGE_ADDR(pde_entry->pt_base_addr);
    return PT_ENTRY_PAGE;
  }
}

pt_entry_type_t pte64_lookup(pte64_t * pt, addr_t addr, addr_t * entry) {
  pte64_t * pte_entry = &(pt[PTE64_INDEX(addr)]);

  if (!pte_entry->present) {
    *entry = 0;
    return PT_ENTRY_NOT_PRESENT;
  } else {
    *entry = BASE_TO_PAGE_ADDR(pte_entry->page_base_addr) + PAGE_OFFSET(addr);
    return PT_ENTRY_PAGE;
  }
}

















pt_access_status_t can_access_pde32(pde32_t * pde, addr_t addr, pf_error_t access_type) {
  pde32_t * entry = &pde[PDE32_INDEX(addr)];

  if (entry->present == 0) {
    return PT_ACCESS_NOT_PRESENT;
  } else if ((entry->writable == 0) && (access_type.write == 1)) {
    return PT_ACCESS_WRITE_ERROR;
  } else if ((entry->user_page == 0) && (access_type.user == 1)) {
    // Check CR0.WP?
    return PT_ACCESS_USER_ERROR;
  }

  return PT_ACCESS_OK;
}


pt_access_status_t can_access_pte32(pte32_t * pte, addr_t addr, pf_error_t access_type) {
  pte32_t * entry = &pte[PTE32_INDEX(addr)];

  if (entry->present == 0) {
    return PT_ACCESS_NOT_PRESENT;
  } else if ((entry->writable == 0) && (access_type.write == 1)) {
    return PT_ACCESS_WRITE_ERROR;
  } else if ((entry->user_page == 0) && (access_type.user == 1)) {
    // Check CR0.WP?
    return PT_ACCESS_USER_ERROR;
  }

  return PT_ACCESS_OK;
}




/* We generate a page table to correspond to a given memory layout
 * pulling pages from the mem_list when necessary
 * If there are any gaps in the layout, we add them as unmapped pages
 */
pde32_t * create_passthrough_pts_32(struct guest_info * guest_info) {
  addr_t current_page_addr = 0;
  int i, j;
  struct shadow_map * map = &(guest_info->mem_map);

  pde32_t * pde = V3_VAddr(V3_AllocPages(1));

  for (i = 0; i < MAX_PDE32_ENTRIES; i++) {
    int pte_present = 0;
    pte32_t * pte = V3_VAddr(V3_AllocPages(1));
    

    for (j = 0; j < MAX_PTE32_ENTRIES; j++) {
      struct shadow_region * region = get_shadow_region_by_addr(map, current_page_addr);

      if (!region || 
	  (region->host_type == HOST_REGION_HOOK) || 
	  (region->host_type == HOST_REGION_UNALLOCATED) || 
	  (region->host_type == HOST_REGION_MEMORY_MAPPED_DEVICE) || 
	  (region->host_type == HOST_REGION_REMOTE) ||
	  (region->host_type == HOST_REGION_SWAPPED)) {
	pte[j].present = 0;
	pte[j].writable = 0;
	pte[j].user_page = 0;
	pte[j].write_through = 0;
	pte[j].cache_disable = 0;
	pte[j].accessed = 0;
	pte[j].dirty = 0;
	pte[j].pte_attr = 0;
	pte[j].global_page = 0;
	pte[j].vmm_info = 0;
	pte[j].page_base_addr = 0;
      } else {
	addr_t host_addr;
	pte[j].present = 1;
	pte[j].writable = 1;
	pte[j].user_page = 1;
	pte[j].write_through = 0;
	pte[j].cache_disable = 0;
	pte[j].accessed = 0;
	pte[j].dirty = 0;
	pte[j].pte_attr = 0;
	pte[j].global_page = 0;
	pte[j].vmm_info = 0;

	if (guest_pa_to_host_pa(guest_info, current_page_addr, &host_addr) == -1) {
	  // BIG ERROR
	  // PANIC
	  return NULL;
	}
	
	pte[j].page_base_addr = host_addr >> 12;
	
	pte_present = 1;
      }

      current_page_addr += PAGE_SIZE;
    }

    if (pte_present == 0) { 
      V3_FreePage(V3_PAddr(pte));

      pde[i].present = 0;
      pde[i].writable = 0;
      pde[i].user_page = 0;
      pde[i].write_through = 0;
      pde[i].cache_disable = 0;
      pde[i].accessed = 0;
      pde[i].reserved = 0;
      pde[i].large_page = 0;
      pde[i].global_page = 0;
      pde[i].vmm_info = 0;
      pde[i].pt_base_addr = 0;
    } else {
      pde[i].present = 1;
      pde[i].writable = 1;
      pde[i].user_page = 1;
      pde[i].write_through = 0;
      pde[i].cache_disable = 0;
      pde[i].accessed = 0;
      pde[i].reserved = 0;
      pde[i].large_page = 0;
      pde[i].global_page = 0;
      pde[i].vmm_info = 0;
      pde[i].pt_base_addr = PAGE_BASE_ADDR((addr_t)V3_PAddr(pte));
    }

  }

  return pde;
}


/* We generate a page table to correspond to a given memory layout
 * pulling pages from the mem_list when necessary
 * If there are any gaps in the layout, we add them as unmapped pages
 */
pdpe32pae_t * create_passthrough_pts_32PAE(struct guest_info * guest_info) {
  addr_t current_page_addr = 0;
  int i, j, k;
  struct shadow_map * map = &(guest_info->mem_map);

  pdpe32pae_t * pdpe = V3_VAddr(V3_AllocPages(1));
  memset(pdpe, 0, PAGE_SIZE);

  for (i = 0; i < MAX_PDPE32PAE_ENTRIES; i++) {
    int pde_present = 0;
    pde32pae_t * pde = V3_VAddr(V3_AllocPages(1));

    for (j = 0; j < MAX_PDE32PAE_ENTRIES; j++) {


      int pte_present = 0;
      pte32pae_t * pte = V3_VAddr(V3_AllocPages(1));
      
      
      for (k = 0; k < MAX_PTE32PAE_ENTRIES; k++) {
	struct shadow_region * region = get_shadow_region_by_addr(map, current_page_addr);
	
	if (!region || 
	    (region->host_type == HOST_REGION_HOOK) || 
	    (region->host_type == HOST_REGION_UNALLOCATED) || 
	    (region->host_type == HOST_REGION_MEMORY_MAPPED_DEVICE) || 
	    (region->host_type == HOST_REGION_REMOTE) ||
	    (region->host_type == HOST_REGION_SWAPPED)) {
	  pte[k].present = 0;
	  pte[k].writable = 0;
	  pte[k].user_page = 0;
	  pte[k].write_through = 0;
	  pte[k].cache_disable = 0;
	  pte[k].accessed = 0;
	  pte[k].dirty = 0;
	  pte[k].pte_attr = 0;
	  pte[k].global_page = 0;
	  pte[k].vmm_info = 0;
	  pte[k].page_base_addr = 0;
	  pte[k].rsvd = 0;
	} else {
	  addr_t host_addr;
	  pte[k].present = 1;
	  pte[k].writable = 1;
	  pte[k].user_page = 1;
	  pte[k].write_through = 0;
	  pte[k].cache_disable = 0;
	  pte[k].accessed = 0;
	  pte[k].dirty = 0;
	  pte[k].pte_attr = 0;
	  pte[k].global_page = 0;
	  pte[k].vmm_info = 0;
	  
	  if (guest_pa_to_host_pa(guest_info, current_page_addr, &host_addr) == -1) {
	    // BIG ERROR
	    // PANIC
	    return NULL;
	  }
	  
	  pte[k].page_base_addr = host_addr >> 12;
	  pte[k].rsvd = 0;

	  pte_present = 1;
	}
	
	current_page_addr += PAGE_SIZE;
      }
      
      if (pte_present == 0) { 
	V3_FreePage(V3_PAddr(pte));
	
	pde[j].present = 0;
	pde[j].writable = 0;
	pde[j].user_page = 0;
	pde[j].write_through = 0;
	pde[j].cache_disable = 0;
	pde[j].accessed = 0;
	pde[j].avail = 0;
	pde[j].large_page = 0;
	pde[j].global_page = 0;
	pde[j].vmm_info = 0;
	pde[j].pt_base_addr = 0;
	pde[j].rsvd = 0;
      } else {
	pde[j].present = 1;
	pde[j].writable = 1;
	pde[j].user_page = 1;
	pde[j].write_through = 0;
	pde[j].cache_disable = 0;
	pde[j].accessed = 0;
	pde[j].avail = 0;
	pde[j].large_page = 0;
	pde[j].global_page = 0;
	pde[j].vmm_info = 0;
	pde[j].pt_base_addr = PAGE_BASE_ADDR((addr_t)V3_PAddr(pte));
	pde[j].rsvd = 0;

	pde_present = 1;
      }
      
    }
    
    if (pde_present == 0) { 
      V3_FreePage(V3_PAddr(pde));
      
      pdpe[i].present = 0;
      pdpe[i].rsvd = 0;
      pdpe[i].write_through = 0;
      pdpe[i].cache_disable = 0;
      pdpe[i].accessed = 0;
      pdpe[i].avail = 0;
      pdpe[i].rsvd2 = 0;
      pdpe[i].vmm_info = 0;
      pdpe[i].pd_base_addr = 0;
      pdpe[i].rsvd3 = 0;
    } else {
      pdpe[i].present = 1;
      pdpe[i].rsvd = 0;
      pdpe[i].write_through = 0;
      pdpe[i].cache_disable = 0;
      pdpe[i].accessed = 0;
      pdpe[i].avail = 0;
      pdpe[i].rsvd2 = 0;
      pdpe[i].vmm_info = 0;
      pdpe[i].pd_base_addr = PAGE_BASE_ADDR((addr_t)V3_PAddr(pde));
      pdpe[i].rsvd3 = 0;
    }
    
  }


  return pdpe;
}






pml4e64_t * create_passthrough_pts_64(struct guest_info * info) {
  addr_t current_page_addr = 0;
  int i, j, k, m;
  struct shadow_map * map = &(info->mem_map);
  
  pml4e64_t * pml = V3_VAddr(V3_AllocPages(1));

  for (i = 0; i < 1; i++) {
    int pdpe_present = 0;
    pdpe64_t * pdpe = V3_VAddr(V3_AllocPages(1));

    for (j = 0; j < 20; j++) {
      int pde_present = 0;
      pde64_t * pde = V3_VAddr(V3_AllocPages(1));

      for (k = 0; k < MAX_PDE64_ENTRIES; k++) {
	int pte_present = 0;
	pte64_t * pte = V3_VAddr(V3_AllocPages(1));


	for (m = 0; m < MAX_PTE64_ENTRIES; m++) {
	  struct shadow_region * region = get_shadow_region_by_addr(map, current_page_addr);
	  

	  
	  if (!region || 
	      (region->host_type == HOST_REGION_HOOK) || 
	      (region->host_type == HOST_REGION_UNALLOCATED) || 
	      (region->host_type == HOST_REGION_MEMORY_MAPPED_DEVICE) || 
	      (region->host_type == HOST_REGION_REMOTE) ||
	      (region->host_type == HOST_REGION_SWAPPED)) {
	    pte[m].present = 0;
	    pte[m].writable = 0;
	    pte[m].user_page = 0;
	    pte[m].write_through = 0;
	    pte[m].cache_disable = 0;
	    pte[m].accessed = 0;
	    pte[m].dirty = 0;
	    pte[m].pte_attr = 0;
	    pte[m].global_page = 0;
	    pte[m].vmm_info = 0;
	    pte[m].page_base_addr = 0;
	  } else {
	    addr_t host_addr;
	    pte[m].present = 1;
	    pte[m].writable = 1;
	    pte[m].user_page = 1;
	    pte[m].write_through = 0;
	    pte[m].cache_disable = 0;
	    pte[m].accessed = 0;
	    pte[m].dirty = 0;
	    pte[m].pte_attr = 0;
	    pte[m].global_page = 0;
	    pte[m].vmm_info = 0;
	    
	    if (guest_pa_to_host_pa(info, current_page_addr, &host_addr) == -1) {
	      // BIG ERROR
	      // PANIC
	      return NULL;
	    }

	    pte[m].page_base_addr = PAGE_BASE_ADDR(host_addr);

	    //PrintPTE64(current_page_addr, &(pte[m]));

	    pte_present = 1;	  
	  }




	  current_page_addr += PAGE_SIZE;
	}
	
	if (pte_present == 0) {
	  V3_FreePage(V3_PAddr(pte));

	  pde[k].present = 0;
	  pde[k].writable = 0;
	  pde[k].user_page = 0;
	  pde[k].write_through = 0;
	  pde[k].cache_disable = 0;
	  pde[k].accessed = 0;
	  pde[k].avail = 0;
	  pde[k].large_page = 0;
	  //pde[k].global_page = 0;
	  pde[k].vmm_info = 0;
	  pde[k].pt_base_addr = 0;
	} else {
	  pde[k].present = 1;
	  pde[k].writable = 1;
	  pde[k].user_page = 1;
	  pde[k].write_through = 0;
	  pde[k].cache_disable = 0;
	  pde[k].accessed = 0;
	  pde[k].avail = 0;
	  pde[k].large_page = 0;
	  //pde[k].global_page = 0;
	  pde[k].vmm_info = 0;
	  pde[k].pt_base_addr = PAGE_BASE_ADDR((addr_t)V3_PAddr(pte));

	  pde_present = 1;
	}
      }

      if (pde_present == 0) {
	V3_FreePage(V3_PAddr(pde));
	
	pdpe[j].present = 0;
	pdpe[j].writable = 0;
	pdpe[j].user_page = 0;
	pdpe[j].write_through = 0;
	pdpe[j].cache_disable = 0;
	pdpe[j].accessed = 0;
	pdpe[j].avail = 0;
	pdpe[j].large_page = 0;
	//pdpe[j].global_page = 0;
	pdpe[j].vmm_info = 0;
	pdpe[j].pd_base_addr = 0;
      } else {
	pdpe[j].present = 1;
	pdpe[j].writable = 1;
	pdpe[j].user_page = 1;
	pdpe[j].write_through = 0;
	pdpe[j].cache_disable = 0;
	pdpe[j].accessed = 0;
	pdpe[j].avail = 0;
	pdpe[j].large_page = 0;
	//pdpe[j].global_page = 0;
	pdpe[j].vmm_info = 0;
	pdpe[j].pd_base_addr = PAGE_BASE_ADDR((addr_t)V3_PAddr(pde));


	pdpe_present = 1;
      }

    }

    PrintDebug("PML index=%d\n", i);

    if (pdpe_present == 0) {
      V3_FreePage(V3_PAddr(pdpe));
      
      pml[i].present = 0;
      pml[i].writable = 0;
      pml[i].user_page = 0;
      pml[i].write_through = 0;
      pml[i].cache_disable = 0;
      pml[i].accessed = 0;
      pml[i].reserved = 0;
      //pml[i].large_page = 0;
      //pml[i].global_page = 0;
      pml[i].vmm_info = 0;
      pml[i].pdp_base_addr = 0;
    } else {
      pml[i].present = 1;
      pml[i].writable = 1;
      pml[i].user_page = 1;
      pml[i].write_through = 0;
      pml[i].cache_disable = 0;
      pml[i].accessed = 0;
      pml[i].reserved = 0;
      //pml[i].large_page = 0;
      //pml[i].global_page = 0;
      pml[i].vmm_info = 0;
      pml[i].pdp_base_addr = PAGE_BASE_ADDR((addr_t)V3_PAddr(pdpe));
    }
  }

  return pml;
}