#ifdef V3_CONFIG_SHADOW_CACHE

static inline int activate_shadow_pt_32(struct guest_info * core) {
    struct cr3_32 * shadow_cr3 = (struct cr3_32 *)&(core->ctrl_regs.cr3);
    struct cr3_32 * guest_cr3 = (struct cr3_32 *)&(core->shdw_pg_state.guest_cr3);

    struct shadow_page_cache_data * shdw_page;

    if (core->n_free_shadow_pages < MIN_FREE_SHADOW_PAGES) {	
	shadow_free_some_pages(core);
    }

    shdw_page = shadow_page_get_page(core, (addr_t)(guest_cr3->pdt_base_addr), 2, 0, 0, 0, 0);
    PrintDebug(info->vm_info, info, "act shdw pt: gcr3 %p\n",(void *)BASE_TO_PAGE_ADDR(guest_cr3->pdt_base_addr));

    shdw_page->cr3 = shdw_page->page_pa;
    
    shadow_cr3->pdt_base_addr = PAGE_BASE_ADDR_4KB(shdw_page->page_pa);
    PrintDebug(info->vm_info, info, "Created new shadow page table %p\n", (void *)BASE_TO_PAGE_ADDR(shadow_cr3->pdt_base_addr));
  
    shadow_cr3->pwt = guest_cr3->pwt;
    shadow_cr3->pcd = guest_cr3->pcd;

    return 0;
}




/* 
 * *
 * * 
 * * 32 bit Page table fault handlers
 * *
 * *
 */

static inline int fix_read_pf_32(pte32_t * shadow_pte, uint_t vmm_info) {
    PrintDebug(info->vm_info, info, "\trdipf, start vmm_info %d\n",vmm_info);
    if((vmm_info & PT_USER_MASK) && !(shadow_pte->user_page)) {
	shadow_pte->user_page = 1;
	shadow_pte->writable = 0;
	return 1;
    }	
    return 0;
}

static inline int fix_write_pf_32(struct guest_info * core, pte32_t * shadow_pte, pte32_t * guest_pte, 
    int user, int * write_pt, addr_t guest_fn, uint_t vmm_info) {
	
    int writable_shadow;
    struct cr0_32 * guest_cr0;
    struct shadow_page_cache_data * page;
    *write_pt = 0;

    PrintDebug(info->vm_info, info, "\twripf, start vmm_info %d\n",vmm_info);
	
    if(shadow_pte->writable) {
	return 0;
    }

    PrintDebug(info->vm_info, info, "\twrpf: pass writable\n");
	
    writable_shadow = vmm_info & PT_WRITABLE_MASK;

    PrintDebug(info->vm_info, info, "\twrpf: writable_shadow %d\n",writable_shadow);
	
    if(user) {
	if(!(vmm_info & PT_USER_MASK) || !writable_shadow) {
	    PrintDebug(info->vm_info, info, "\twrpf: 1st usr chk\n");
	    return 0;
	}
    } else {
	if(!writable_shadow) {
	    guest_cr0 = (struct cr0_32 *)&(core->shdw_pg_state.guest_cr0);
	    PrintDebug(info->vm_info, info, "\twrpf: wp %d\n",guest_cr0->wp);

	    if (guest_cr0->wp) {
	        return 0;
	    }
	    shadow_pte->user_page = 0;				
	}
    }
			
    if (guest_pte->present == 0) { 
	memset((void *)shadow_pte, 0, sizeof(uint32_t));
	PrintDebug(info->vm_info, info, "\twrpf: guest non present\n");
	return 0;
    }

    if (user) {
	while ((page = shadow_page_lookup_page(core, guest_fn, 0)) != NULL) {
	    shadow_zap_page(core,page);
	}

	PrintDebug(info->vm_info, info, "\twrpf: zap\n");

    } else if((page = shadow_page_lookup_page(core, guest_fn,0))  != NULL)  {
	if ((page = shadow_page_lookup_page(core, guest_fn,0)) != NULL) {
	    guest_pte->dirty = 1;
	    *write_pt = 1;
	    PrintDebug(info->vm_info, info, "\twrpf: write need\n");
	    return 0;
	}
    }	

    shadow_pte->writable = 1; //will lost every pt update trap not sure for this
    guest_pte->dirty = 1;	
	
    rmap_add(core, (addr_t)shadow_pte);
	
    PrintDebug(info->vm_info, info, "\twrpf: on writable\n");
    return 1;
}

#endif


static int handle_4MB_shadow_pagefault_32(struct guest_info * core,  addr_t fault_addr, pf_error_t error_code, 
					  pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde);

static int handle_pte_shadow_pagefault_32(struct guest_info * core, addr_t fault_addr, pf_error_t error_code,
					  pte32_t * shadow_pt,  pte32_t * guest_pt);


static inline int handle_shadow_pagefault_32(struct guest_info * core, addr_t fault_addr, pf_error_t error_code) {
    pde32_t * guest_pd = NULL;
    pde32_t * shadow_pd = CR3_TO_PDE32_VA(core->ctrl_regs.cr3);
    addr_t guest_cr3 = CR3_TO_PDE32_PA(core->shdw_pg_state.guest_cr3);
    pt_access_status_t guest_pde_access;
    pt_access_status_t shadow_pde_access;
    pde32_t * guest_pde = NULL;
    pde32_t * shadow_pde = (pde32_t *)&(shadow_pd[PDE32_INDEX(fault_addr)]);

    PrintDebug(info->vm_info, info, "Shadow page fault handler: %p\n", (void*) fault_addr );
    PrintDebug(info->vm_info, info, "Handling PDE32 Fault\n");

    if (guest_pa_to_host_va(core, guest_cr3, (addr_t*)&guest_pd) == -1) {
	PrintError(info->vm_info, info, "Invalid Guest PDE Address: 0x%p\n",  (void *)guest_cr3);
	return -1;
    } 

    guest_pde = (pde32_t *)&(guest_pd[PDE32_INDEX(fault_addr)]);


    // Check the guest page permissions
    guest_pde_access = v3_can_access_pde32(guest_pd, fault_addr, error_code);

    // Check the shadow page permissions
    shadow_pde_access = v3_can_access_pde32(shadow_pd, fault_addr, error_code);
  
    /* Was the page fault caused by the Guest's page tables? */
    if (v3_is_guest_pf(guest_pde_access, shadow_pde_access) == 1) {
	PrintDebug(info->vm_info, info, "Injecting PDE pf to guest: (guest access error=%d) (shdw access error=%d)  (pf error code=%d)\n", 
		   *(uint_t *)&guest_pde_access, *(uint_t *)&shadow_pde_access, *(uint_t *)&error_code);
	if (v3_inject_guest_pf(core, fault_addr, error_code) == -1) {
	    PrintError(info->vm_info, info, "Could not inject guest page fault for vaddr %p\n", (void *)fault_addr);
	    return -1;
	}
	return 0;
    }



    if (shadow_pde_access == PT_ACCESS_USER_ERROR) {
	// 
	// PDE Entry marked non user
	//
	PrintDebug(info->vm_info, info, "Shadow Paging User access error (shadow_pde_access=0x%x, guest_pde_access=0x%x)\n", 
		   shadow_pde_access, guest_pde_access);
	
	if (v3_inject_guest_pf(core, fault_addr, error_code) == -1) {
	    PrintError(info->vm_info, info, "Could not inject guest page fault for vaddr %p\n", (void *)fault_addr);
	    return -1;
	}
	return 0;
    } else if ((shadow_pde_access == PT_ACCESS_WRITE_ERROR) && 
	       (guest_pde->large_page == 1)) {
	
	((pde32_4MB_t *)guest_pde)->dirty = 1;
	shadow_pde->writable = guest_pde->writable;
	return 0;
    } else if ((shadow_pde_access != PT_ACCESS_NOT_PRESENT) &&
	       (shadow_pde_access != PT_ACCESS_OK)) {
    	// inject page fault in guest
	if (v3_inject_guest_pf(core, fault_addr, error_code) == -1) {
	    PrintError(info->vm_info, info, "Could not inject guest page fault for vaddr %p\n", (void *)fault_addr);
	    return -1;
	}
	PrintDebug(info->vm_info, info, "Unknown Error occurred (shadow_pde_access=%d)\n", shadow_pde_access);
	PrintDebug(info->vm_info, info, "Manual Says to inject page fault into guest\n");
	return 0;
    }

  
    pte32_t * shadow_pt = NULL;
    pte32_t * guest_pt = NULL;

    // Get the next shadow page level, allocate if not present

    if (shadow_pde_access == PT_ACCESS_NOT_PRESENT) {
	struct shadow_page_data * shdw_page =  create_new_shadow_pt(core);
	shadow_pt = (pte32_t *)V3_VAddr((void *)shdw_page->page_pa);

	shadow_pde->present = 1;
	shadow_pde->user_page = guest_pde->user_page;


	if (guest_pde->large_page == 0) {
	    shadow_pde->writable = guest_pde->writable;
	} else {
	    // This large page flag is temporary until we can get a working cache....
	    ((pde32_4MB_t *)guest_pde)->vmm_info = V3_LARGE_PG;

	    if (error_code.write) {
		shadow_pde->writable = guest_pde->writable;
		((pde32_4MB_t *)guest_pde)->dirty = 1;
	    } else {
		shadow_pde->writable = 0;
		((pde32_4MB_t *)guest_pde)->dirty = 0;
	    }
	}
      

	// VMM Specific options
	shadow_pde->write_through = guest_pde->write_through;
	shadow_pde->cache_disable = guest_pde->cache_disable;
	shadow_pde->global_page = guest_pde->global_page;
	//
      
	guest_pde->accessed = 1;
      



	shadow_pde->pt_base_addr = PAGE_BASE_ADDR(shdw_page->page_pa);
    } else {
	shadow_pt = (pte32_t *)V3_VAddr((void *)BASE_TO_PAGE_ADDR(shadow_pde->pt_base_addr));
    }


      
    if (guest_pde->large_page == 0) {
	if (guest_pa_to_host_va(core, BASE_TO_PAGE_ADDR(guest_pde->pt_base_addr), (addr_t*)&guest_pt) == -1) {
	    // Machine check the guest
	    PrintDebug(info->vm_info, info, "Invalid Guest PTE Address: 0x%p\n", (void *)BASE_TO_PAGE_ADDR(guest_pde->pt_base_addr));
	    v3_raise_exception(core, MC_EXCEPTION);
	    return 0;
	}

	if (handle_pte_shadow_pagefault_32(core, fault_addr, error_code, shadow_pt, guest_pt)  == -1) {
	    PrintError(info->vm_info, info, "Error handling Page fault caused by PTE\n");
	    return -1;
	}
    } else {
	if (handle_4MB_shadow_pagefault_32(core, fault_addr, error_code, shadow_pt, (pde32_4MB_t *)guest_pde) == -1) {
	    PrintError(info->vm_info, info, "Error handling large pagefault\n");
	    return -1;
	}	
    }

    return 0;
}


static int handle_pte_shadow_pagefault_32(struct guest_info * core, addr_t fault_addr, pf_error_t error_code,
					  pte32_t * shadow_pt, pte32_t * guest_pt) {

    pt_access_status_t guest_pte_access;
    pt_access_status_t shadow_pte_access;
    pte32_t * guest_pte = (pte32_t *)&(guest_pt[PTE32_INDEX(fault_addr)]);;
    pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(fault_addr)]);
    addr_t guest_pa = BASE_TO_PAGE_ADDR((addr_t)(guest_pte->page_base_addr)) +  PAGE_OFFSET(fault_addr);

    struct v3_mem_region * shdw_reg =  v3_get_mem_region(core->vm_info, core->vcpu_id, guest_pa);

    if (shdw_reg == NULL) {
	// Inject a machine check in the guest
	PrintDebug(info->vm_info, info, "Invalid Guest Address in page table (0x%p)\n", (void *)guest_pa);
	v3_raise_exception(core, MC_EXCEPTION);
	return 0;
    }

    // Check the guest page permissions
    guest_pte_access = v3_can_access_pte32(guest_pt, fault_addr, error_code);

    // Check the shadow page permissions
    shadow_pte_access = v3_can_access_pte32(shadow_pt, fault_addr, error_code);
  
  
    /* Was the page fault caused by the Guest's page tables? */
    if (v3_is_guest_pf(guest_pte_access, shadow_pte_access) == 1) {

	PrintDebug(info->vm_info, info, "Access error injecting pf to guest (guest access error=%d) (pf error code=%d)\n", 
		   guest_pte_access, *(uint_t*)&error_code);
	

	//   inject:
	if (v3_inject_guest_pf(core, fault_addr, error_code) == -1) {
	    PrintError(info->vm_info, info, "Could not inject guest page fault for vaddr %p\n", (void *)fault_addr);
	    return -1;
	}	

	return 0; 
    }

  
  
    if (shadow_pte_access == PT_ACCESS_OK) {
	// Inconsistent state...
	// Guest Re-Entry will flush page tables and everything should now work
	PrintDebug(info->vm_info, info, "Inconsistent state... Guest re-entry should flush tlb\n");
	return 0;
    }


    if (shadow_pte_access == PT_ACCESS_NOT_PRESENT) {
	// Page Table Entry Not Present
	PrintDebug(info->vm_info, info, "guest_pa =%p\n", (void *)guest_pa);

	if ((shdw_reg->host_type == SHDW_REGION_ALLOCATED) ||
	    (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK)) {
	    addr_t shadow_pa = v3_get_shadow_addr(shdw_reg, core->vcpu_id, guest_pa);
      
	    shadow_pte->page_base_addr = PAGE_BASE_ADDR(shadow_pa);

	    PrintDebug(info->vm_info, info, "\tMapping shadow page (%p)\n", (void *)BASE_TO_PAGE_ADDR(shadow_pte->page_base_addr));
      
	    shadow_pte->present = guest_pte->present;
	    shadow_pte->user_page = guest_pte->user_page;
      
	    //set according to VMM policy
	    shadow_pte->write_through = guest_pte->write_through;
	    shadow_pte->cache_disable = guest_pte->cache_disable;
	    shadow_pte->global_page = guest_pte->global_page;
	    //
      
	    guest_pte->accessed = 1;
      
	    if (guest_pte->dirty == 1) {
		shadow_pte->writable = guest_pte->writable;
	    } else if ((guest_pte->dirty == 0) && (error_code.write == 1)) {
		shadow_pte->writable = guest_pte->writable;
		guest_pte->dirty = 1;
	    } else if ((guest_pte->dirty == 0) && (error_code.write == 0)) {
		shadow_pte->writable = 0;
	    }



	    // Write hooks trump all, and are set Read Only
	    if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
		shadow_pte->writable = 0;
	    }

	} else {
	    // Page fault handled by hook functions

	    if (v3_handle_mem_full_hook(core, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
		PrintError(info->vm_info, info, "Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
		return -1;
	    }
	}
    } else if (shadow_pte_access == PT_ACCESS_WRITE_ERROR) {
	guest_pte->dirty = 1;

	if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
	    if (v3_handle_mem_wr_hook(core, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
		PrintError(info->vm_info, info, "Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
		return -1;
	    }
	} else {
	    PrintDebug(info->vm_info, info, "Shadow PTE Write Error\n");
	    shadow_pte->writable = guest_pte->writable;
	}


	return 0;

    } else {
	// Inject page fault into the guest	
	if (v3_inject_guest_pf(core, fault_addr, error_code) == -1) {
	    PrintError(info->vm_info, info, "Could not inject guest page fault for vaddr %p\n", (void *)fault_addr);
	    return -1;
	}

	PrintError(info->vm_info, info, "PTE Page fault fell through... Not sure if this should ever happen\n");
	PrintError(info->vm_info, info, "Manual Says to inject page fault into guest\n");
	return -1;
    }

    return 0;
}



static int handle_4MB_shadow_pagefault_32(struct guest_info * core, 
				     addr_t fault_addr, pf_error_t error_code, 
				     pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde) 
{
    pt_access_status_t shadow_pte_access = v3_can_access_pte32(shadow_pt, fault_addr, error_code);
    pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(fault_addr)]);
    addr_t guest_fault_pa = BASE_TO_PAGE_ADDR_4MB(large_guest_pde->page_base_addr) + PAGE_OFFSET_4MB(fault_addr);  


    PrintDebug(info->vm_info, info, "Handling 4MB fault (guest_fault_pa=%p) (error_code=%x)\n", (void *)guest_fault_pa, *(uint_t*)&error_code);
    PrintDebug(info->vm_info, info, "ShadowPT=%p, LargeGuestPDE=%p\n", shadow_pt, large_guest_pde);

    struct v3_mem_region * shdw_reg = v3_get_mem_region(core->vm_info, core->vcpu_id, guest_fault_pa);

 
    if (shdw_reg == NULL) {
	// Inject a machine check in the guest
	PrintDebug(info->vm_info, info, "Invalid Guest Address in page table (0x%p)\n", (void *)guest_fault_pa);
	v3_raise_exception(core, MC_EXCEPTION);
	return -1;
    }

    if (shadow_pte_access == PT_ACCESS_OK) {
	// Inconsistent state...
	// Guest Re-Entry will flush tables and everything should now workd
	PrintDebug(info->vm_info, info, "Inconsistent state... Guest re-entry should flush tlb\n");
	return 0;
    }

  
    if (shadow_pte_access == PT_ACCESS_NOT_PRESENT) {
	// Get the guest physical address of the fault

	if ((shdw_reg->host_type == SHDW_REGION_ALLOCATED) || 
	    (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK)) {
	    addr_t shadow_pa = v3_get_shadow_addr(shdw_reg, core->vcpu_id, guest_fault_pa);

	    shadow_pte->page_base_addr = PAGE_BASE_ADDR(shadow_pa);

	    PrintDebug(info->vm_info, info, "\tMapping shadow page (%p)\n", (void *)BASE_TO_PAGE_ADDR(shadow_pte->page_base_addr));

	    shadow_pte->present = 1;

	    /* We are assuming that the PDE entry has precedence
	     * so the Shadow PDE will mirror the guest PDE settings, 
	     * and we don't have to worry about them here
	     * Allow everything
	     */
	    shadow_pte->user_page = 1;

	    if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
		shadow_pte->writable = 0;
	    } else {
		shadow_pte->writable = 1;
	    }

	    //set according to VMM policy
	    shadow_pte->write_through = large_guest_pde->write_through;
	    shadow_pte->cache_disable = large_guest_pde->cache_disable;
	    shadow_pte->global_page = large_guest_pde->global_page;
	    //
      
	} else {
	    if (v3_handle_mem_full_hook(core, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
		PrintError(info->vm_info, info, "Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
		return -1;
	    }
	}
    } else if (shadow_pte_access == PT_ACCESS_WRITE_ERROR) {

	if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {

	    if (v3_handle_mem_wr_hook(core, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
		PrintError(info->vm_info, info, "Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
		return -1;
	    }
	}

    } else {
	PrintError(info->vm_info, info, "Error in large page fault handler...\n");
	PrintError(info->vm_info, info, "This case should have been handled at the top level handler\n");
	return -1;
    }

    PrintDebug(info->vm_info, info, "Returning from large page fault handler\n");
    return 0;
}












/* If we start to optimize we should look up the guest pages in the cache... */
static inline int handle_shadow_invlpg_32(struct guest_info * core, addr_t vaddr) {
    pde32_t * shadow_pd = (pde32_t *)CR3_TO_PDE32_VA(core->ctrl_regs.cr3);
    pde32_t * shadow_pde = (pde32_t *)&shadow_pd[PDE32_INDEX(vaddr)];

    addr_t guest_cr3 =  CR3_TO_PDE32_PA(core->shdw_pg_state.guest_cr3);
    pde32_t * guest_pd = NULL;
    pde32_t * guest_pde;

    if (guest_pa_to_host_va(core, guest_cr3, (addr_t*)&guest_pd) == -1) {
	PrintError(info->vm_info, info, "Invalid Guest PDE Address: 0x%p\n",  (void *)guest_cr3);
	return -1;
    }
  
    guest_pde = (pde32_t *)&(guest_pd[PDE32_INDEX(vaddr)]);
  
    if (guest_pde->large_page == 1) {
	shadow_pde->present = 0;
	PrintDebug(info->vm_info, info, "Invalidating Large Page\n");
    } else if (shadow_pde->present == 1) {
	pte32_t * shadow_pt = (pte32_t *)(addr_t)BASE_TO_PAGE_ADDR_4KB(shadow_pde->pt_base_addr);
	pte32_t * shadow_pte = (pte32_t *) V3_VAddr( (void*) &shadow_pt[PTE32_INDEX(vaddr)] );
    
	PrintDebug(info->vm_info, info, "Setting not present\n");
    
	shadow_pte->present = 0;
    }
    return 0;
}

#endif