moved internal memory map routines over to new flags structure instead of the hardcod...

diff --git a/palacios/include/palacios/vmm_mem.h b/palacios/include/palacios/vmm_mem.h
index 14423fe..727655e 100644 (file)
--- a/palacios/include/palacios/vmm_mem.h
+++ b/palacios/include/palacios/vmm_mem.h
@@ -42,17 +42,36 @@ typedef enum shdw_region_type {
     SHDW_REGION_WRITE_HOOK,                 // This region is mapped as read-only (page faults on write)
     SHDW_REGION_FULL_HOOK,                  // This region is mapped as not present (always generate page faults)
     SHDW_REGION_ALLOCATED,                  // Region is a section of host memory
+    SHDW_REGION_BASE,
 } v3_shdw_region_type_t;
 
 #define V3_MEM_CORE_ANY ((uint16_t)-1)
 
 
+
+typedef struct {
+    union {
+       uint16_t value;
+       struct {
+           uint8_t read   : 1;
+           uint8_t write  : 1;
+           uint8_t exec   : 1;
+           uint8_t hook   : 1;
+           uint8_t base   : 1;
+           uint8_t alloced : 1;
+       } __attribute__((packed));
+    } __attribute__((packed));
+} __attribute__((packed)) v3_mem_flags_t;
+
+
+
 struct v3_shadow_region {
     addr_t                  guest_start; 
     addr_t                  guest_end; 
 
     v3_shdw_region_type_t   host_type;
-  
+    v3_mem_flags_t          flags;
+
     addr_t                  host_addr; // This either points to a host address mapping
 
     // Called when data is read from a memory page
@@ -110,28 +129,21 @@ void v3_delete_shadow_region(struct v3_vm_info * vm, struct v3_shadow_region * r
 
 
 struct v3_shadow_region * v3_get_shadow_region(struct v3_vm_info * vm, uint16_t core_id, addr_t guest_addr);
-addr_t v3_get_shadow_addr(struct v3_shadow_region * reg, uint16_t core_id, addr_t guest_addr);
 
 
-
-
-
-void v3_print_mem_map(struct v3_vm_info * vm);
+addr_t v3_get_shadow_addr(struct v3_shadow_region * reg, uint16_t core_id, addr_t guest_addr);
 
 
 
 
 
-const uchar_t * v3_shdw_region_type_to_str(v3_shdw_region_type_t type);
+void v3_print_mem_map(struct v3_vm_info * vm);
 
 
 
-int handle_special_page_fault(struct guest_info * info, addr_t fault_addr, addr_t gp_addr, pf_error_t access_info);
+int v3_handle_mem_hook(struct guest_info * info, addr_t guest_va, addr_t guest_pa, 
+                      struct v3_shadow_region * reg, pf_error_t access_info);
 
-int v3_handle_mem_wr_hook(struct guest_info * info, addr_t guest_va, addr_t guest_pa, 
-                         struct v3_shadow_region * reg, pf_error_t access_info);
-int v3_handle_mem_full_hook(struct guest_info * info, addr_t guest_va, addr_t guest_pa, 
-                           struct v3_shadow_region * reg, pf_error_t access_info);
 
 #endif // ! __V3VEE__
 

diff --git a/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_32.h b/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_32.h
index 7a0ea14..1feb2e5 100644 (file)
--- a/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_32.h
+++ b/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_32.h
@@ -376,7 +376,7 @@ static int handle_pte_shadow_pagefault_32(struct guest_info * info, addr_t fault
        } else {
            // Page fault handled by hook functions
 
-           if (v3_handle_mem_full_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
+           if (v3_handle_mem_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
                PrintError("Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
                return -1;
            }
@@ -385,7 +385,7 @@ static int handle_pte_shadow_pagefault_32(struct guest_info * info, addr_t fault
        guest_pte->dirty = 1;
 
        if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
-           if (v3_handle_mem_wr_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
+           if (v3_handle_mem_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
                PrintError("Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
                return -1;
            }
@@ -477,7 +477,7 @@ static int handle_4MB_shadow_pagefault_32(struct guest_info * info,
            //
       
        } else {
-           if (v3_handle_mem_full_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
+           if (v3_handle_mem_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
                PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
                return -1;
            }
@@ -486,7 +486,7 @@ static int handle_4MB_shadow_pagefault_32(struct guest_info * info,
 
        if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
 
-           if (v3_handle_mem_wr_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
+           if (v3_handle_mem_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
                PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
                return -1;
            }

diff --git a/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_64.h b/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_64.h
index 8f01d7c..f0dcfdb 100644 (file)
--- a/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_64.h
+++ b/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_64.h
@@ -487,7 +487,7 @@ static int handle_pte_shadow_pagefault_64(struct guest_info * info, addr_t fault
        } else {
            // Page fault handled by hook functions
 
-           if (v3_handle_mem_full_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
+           if (v3_handle_mem_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
                PrintError("Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
                return -1;
            }
@@ -496,7 +496,7 @@ static int handle_pte_shadow_pagefault_64(struct guest_info * info, addr_t fault
        guest_pte->dirty = 1;
 
        if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
-           if (v3_handle_mem_wr_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
+           if (v3_handle_mem_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
                PrintError("Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
                return -1;
            }
@@ -586,7 +586,7 @@ static int handle_2MB_shadow_pagefault_64(struct guest_info * info,
            //
       
        } else {
-           if (v3_handle_mem_full_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
+           if (v3_handle_mem_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
                PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
                return -1;
            }
@@ -595,7 +595,7 @@ static int handle_2MB_shadow_pagefault_64(struct guest_info * info,
 
        if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
 
-           if (v3_handle_mem_wr_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
+           if (v3_handle_mem_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
                PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
                return -1;
            }

diff --git a/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_32.h b/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_32.h
index 3958250..4771c0e 100644 (file)
--- a/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_32.h
+++ b/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_32.h
@@ -286,7 +286,7 @@ static int handle_pte_shadow_pagefault_32(struct guest_info * info, addr_t fault
        } else {
            // Page fault handled by hook functions
 
-           if (v3_handle_mem_full_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
+           if (v3_handle_mem_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
                PrintError("Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
                return -1;
            }
@@ -295,7 +295,7 @@ static int handle_pte_shadow_pagefault_32(struct guest_info * info, addr_t fault
        guest_pte->dirty = 1;
 
        if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
-           if (v3_handle_mem_wr_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
+           if (v3_handle_mem_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
                PrintError("Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
                return -1;
            }
@@ -387,7 +387,7 @@ static int handle_4MB_shadow_pagefault_32(struct guest_info * info,
            //
       
        } else {
-           if (v3_handle_mem_full_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
+           if (v3_handle_mem_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
                PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
                return -1;
            }
@@ -396,7 +396,7 @@ static int handle_4MB_shadow_pagefault_32(struct guest_info * info,
 
        if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
 
-           if (v3_handle_mem_wr_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
+           if (v3_handle_mem_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
                PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
                return -1;
            }

diff --git a/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_64.h b/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_64.h
index 8f01d7c..f0dcfdb 100644 (file)
--- a/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_64.h
+++ b/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_64.h
@@ -487,7 +487,7 @@ static int handle_pte_shadow_pagefault_64(struct guest_info * info, addr_t fault
        } else {
            // Page fault handled by hook functions
 
-           if (v3_handle_mem_full_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
+           if (v3_handle_mem_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
                PrintError("Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
                return -1;
            }
@@ -496,7 +496,7 @@ static int handle_pte_shadow_pagefault_64(struct guest_info * info, addr_t fault
        guest_pte->dirty = 1;
 
        if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
-           if (v3_handle_mem_wr_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
+           if (v3_handle_mem_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
                PrintError("Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
                return -1;
            }
@@ -586,7 +586,7 @@ static int handle_2MB_shadow_pagefault_64(struct guest_info * info,
            //
       
        } else {
-           if (v3_handle_mem_full_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
+           if (v3_handle_mem_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
                PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
                return -1;
            }
@@ -595,7 +595,7 @@ static int handle_2MB_shadow_pagefault_64(struct guest_info * info,
 
        if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
 
-           if (v3_handle_mem_wr_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
+           if (v3_handle_mem_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
                PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
                return -1;
            }

diff --git a/palacios/src/palacios/vm_guest_mem.c b/palacios/src/palacios/vm_guest_mem.c
index 2aa7c58..a13256b 100644 (file)
--- a/palacios/src/palacios/vm_guest_mem.c
+++ b/palacios/src/palacios/vm_guest_mem.c
@@ -72,9 +72,9 @@ int guest_pa_to_host_pa(struct guest_info * info, addr_t guest_pa, addr_t * host
        return -1;
     }
     
-    if (shdw_reg->host_type == SHDW_REGION_FULL_HOOK) {
-       PrintError("In GPA->HPA: Could not find address in shadow map (addr=%p) (reg_type=%s)\n", 
-                  (void *)guest_pa, v3_shdw_region_type_to_str(shdw_reg->host_type));
+    if (shdw_reg->flags.alloced == 0) {
+       PrintError("In GPA->HPA: Tried to translate physical address of non allocated page (addr=%p)\n", 
+                  (void *)guest_pa);
        return -1;
     }
        

diff --git a/palacios/src/palacios/vmm_direct_paging_32.h b/palacios/src/palacios/vmm_direct_paging_32.h
index bfbb4a3..e7e4a5a 100644 (file)
--- a/palacios/src/palacios/vmm_direct_paging_32.h
+++ b/palacios/src/palacios/vmm_direct_paging_32.h
@@ -90,7 +90,7 @@ static inline int handle_passthrough_pagefault_32(struct guest_info * info,
            pte[pte_index].page_base_addr = PAGE_BASE_ADDR(host_addr);
        } else if (region->host_type == SHDW_REGION_FULL_HOOK) {
            // trap all accesses
-           return v3_handle_mem_full_hook(info, fault_addr, fault_addr, region, error_code);
+           return v3_handle_mem_hook(info, fault_addr, fault_addr, region, error_code);
        } else {
            PrintError("Unknown Region Type...\n");
            return -1;
@@ -100,7 +100,7 @@ static inline int handle_passthrough_pagefault_32(struct guest_info * info,
     if ( (region->host_type == SHDW_REGION_WRITE_HOOK) && 
         (error_code.write == 1) ) {
        PrintDebug("Triggering Direct paging Write hook\n");
-       return v3_handle_mem_wr_hook(info, fault_addr, fault_addr, region, error_code);
+       return v3_handle_mem_hook(info, fault_addr, fault_addr, region, error_code);
     }
 
     

diff --git a/palacios/src/palacios/vmm_direct_paging_32pae.h b/palacios/src/palacios/vmm_direct_paging_32pae.h
index f7c1f76..7ce823f 100644 (file)
--- a/palacios/src/palacios/vmm_direct_paging_32pae.h
+++ b/palacios/src/palacios/vmm_direct_paging_32pae.h
@@ -103,7 +103,7 @@ static inline int handle_passthrough_pagefault_32pae(struct guest_info * info,
 
        } else if (region->host_type == SHDW_REGION_FULL_HOOK) {
            // trap all accesses
-           return v3_handle_mem_full_hook(info, fault_addr, fault_addr, region, error_code);
+           return v3_handle_mem_hook(info, fault_addr, fault_addr, region, error_code);
 
        } else {
            PrintError("Unknown Region Type...\n");
@@ -113,7 +113,7 @@ static inline int handle_passthrough_pagefault_32pae(struct guest_info * info,
    
     if ( (region->host_type == SHDW_REGION_WRITE_HOOK) && 
         (error_code.write == 1) ) {
-       return v3_handle_mem_wr_hook(info, fault_addr, fault_addr, region, error_code);
+       return v3_handle_mem_hook(info, fault_addr, fault_addr, region, error_code);
     }
 
     return 0;

diff --git a/palacios/src/palacios/vmm_direct_paging_64.h b/palacios/src/palacios/vmm_direct_paging_64.h
index 0511754..907a99a 100644 (file)
--- a/palacios/src/palacios/vmm_direct_paging_64.h
+++ b/palacios/src/palacios/vmm_direct_paging_64.h
@@ -127,7 +127,7 @@ static inline int handle_passthrough_pagefault_64(struct guest_info * info,
 
        } else if (region->host_type == SHDW_REGION_FULL_HOOK) {
            // trap all accesses
-           return v3_handle_mem_full_hook(info, fault_addr, fault_addr, region, error_code);
+           return v3_handle_mem_hook(info, fault_addr, fault_addr, region, error_code);
 
        } else {
            PrintError("Unknown Region Type...\n");
@@ -137,7 +137,7 @@ static inline int handle_passthrough_pagefault_64(struct guest_info * info,
    
     if ( (region->host_type == SHDW_REGION_WRITE_HOOK) && 
         (error_code.write == 1) ) {
-       return v3_handle_mem_wr_hook(info, fault_addr, fault_addr, region, error_code);
+       return v3_handle_mem_hook(info, fault_addr, fault_addr, region, error_code);
     }
 
     return 0;

diff --git a/palacios/src/palacios/vmm_mem.c b/palacios/src/palacios/vmm_mem.c
index f2d527a..cb3f144 100644 (file)
--- a/palacios/src/palacios/vmm_mem.c
+++ b/palacios/src/palacios/vmm_mem.c
@@ -46,6 +46,8 @@ int v3_init_mem_map(struct v3_vm_info * vm) {
     struct v3_mem_map * map = &(vm->mem_map);
     addr_t mem_pages = vm->mem_size >> 12;
 
+    memset(&(map->base_region), 0, sizeof(struct v3_shadow_region));
+
     map->shdw_regions.rb_node = NULL;
 
 
@@ -60,6 +62,11 @@ int v3_init_mem_map(struct v3_vm_info * vm) {
     map->base_region.host_type = SHDW_REGION_ALLOCATED;
     map->base_region.host_addr = (addr_t)V3_AllocPages(mem_pages);
 
+    map->base_region.flags.read = 1;
+    map->base_region.flags.write = 1;
+    map->base_region.flags.exec = 1;
+    map->base_region.flags.base = 1;
+    map->base_region.flags.alloced = 1;
 
     if ((void *)map->base_region.host_addr == NULL) {
        PrintError("Could not allocate Guest memory\n");
@@ -104,6 +111,7 @@ int v3_add_shadow_mem( struct v3_vm_info * vm, uint16_t core_id,
                       addr_t               host_addr)
 {
     struct v3_shadow_region * entry = (struct v3_shadow_region *)V3_Malloc(sizeof(struct v3_shadow_region));
+    memset(entry, 0, sizeof(struct v3_shadow_region));
 
     entry->guest_start = guest_addr_start;
     entry->guest_end = guest_addr_end;
@@ -114,6 +122,11 @@ int v3_add_shadow_mem( struct v3_vm_info * vm, uint16_t core_id,
     entry->priv_data = NULL;
     entry->core_id = core_id;
 
+    entry->flags.read = 1;
+    entry->flags.write = 1;
+    entry->flags.exec = 1;
+    entry->flags.alloced = 1;
+
     if (insert_shadow_region(vm, entry)) {
        V3_Free(entry);
        return -1;
@@ -130,7 +143,7 @@ int v3_hook_write_mem(struct v3_vm_info * vm, uint16_t core_id,
                      void * priv_data) {
 
     struct v3_shadow_region * entry = (struct v3_shadow_region *)V3_Malloc(sizeof(struct v3_shadow_region));
-
+    memset(entry, 0, sizeof(struct v3_shadow_region));
 
     entry->guest_start = guest_addr_start;
     entry->guest_end = guest_addr_end;
@@ -141,6 +154,12 @@ int v3_hook_write_mem(struct v3_vm_info * vm, uint16_t core_id,
     entry->priv_data = priv_data;
     entry->core_id = core_id;
 
+    entry->flags.hook = 1;
+    entry->flags.read = 1;
+    entry->flags.exec = 1;
+    entry->flags.alloced = 1;
+
+
     if (insert_shadow_region(vm, entry)) {
        V3_Free(entry);
        return -1;
@@ -156,6 +175,7 @@ int v3_hook_full_mem(struct v3_vm_info * vm, uint16_t core_id,
                     void * priv_data) {
   
     struct v3_shadow_region * entry = (struct v3_shadow_region *)V3_Malloc(sizeof(struct v3_shadow_region));
+    memset(entry, 0, sizeof(struct v3_shadow_region));
 
     entry->guest_start = guest_addr_start;
     entry->guest_end = guest_addr_end;
@@ -166,6 +186,8 @@ int v3_hook_full_mem(struct v3_vm_info * vm, uint16_t core_id,
     entry->priv_data = priv_data;
     entry->core_id = core_id;
 
+    entry->flags.hook = 1;
+
     if (insert_shadow_region(vm, entry)) {
        V3_Free(entry);
        return -1;
@@ -180,8 +202,7 @@ int v3_hook_full_mem(struct v3_vm_info * vm, uint16_t core_id,
 int v3_unhook_mem(struct v3_vm_info * vm, uint16_t core_id, addr_t guest_addr_start) {
     struct v3_shadow_region * reg = v3_get_shadow_region(vm, core_id, guest_addr_start);
 
-    if ((reg->host_type != SHDW_REGION_FULL_HOOK) || 
-       (reg->host_type != SHDW_REGION_WRITE_HOOK)) {
+    if (!reg->flags.hook) {
        PrintError("Trying to unhook a non hooked memory region (addr=%p)\n", (void *)guest_addr_start);
        return -1;
     }
@@ -282,65 +303,52 @@ struct v3_shadow_region * insert_shadow_region(struct v3_vm_info * vm,
 
 
 
-int handle_special_page_fault(struct guest_info * info,
-                             addr_t fault_gva, addr_t fault_gpa, pf_error_t access_info) 
-{
-    struct v3_shadow_region * reg = v3_get_shadow_region(info->vm_info, info->cpu_id, fault_gpa);
 
-    PrintDebug("Handling Special Page Fault\n");
 
-    switch (reg->host_type) {
-       case SHDW_REGION_WRITE_HOOK:
-           return v3_handle_mem_wr_hook(info, fault_gva, fault_gpa, reg, access_info);
-       case SHDW_REGION_FULL_HOOK:
-           return v3_handle_mem_full_hook(info, fault_gva, fault_gpa, reg, access_info);
-       default:
-           return -1;
-    }
+int v3_handle_mem_hook(struct guest_info * info, addr_t guest_va, addr_t guest_pa, 
+                      struct v3_shadow_region * reg, pf_error_t access_info) {
 
-    return 0;
-
-}
-
-int v3_handle_mem_wr_hook(struct guest_info * info, addr_t guest_va, addr_t guest_pa, 
-                         struct v3_shadow_region * reg, pf_error_t access_info) {
+    addr_t op_addr = 0;
 
-    addr_t dst_addr = (addr_t)V3_VAddr((void *)v3_get_shadow_addr(reg, info->cpu_id, guest_pa));
-
-    if (v3_emulate_write_op(info, guest_va, guest_pa, dst_addr, 
-                           reg->write_hook, reg->priv_data) == -1) {
-       PrintError("Write hook emulation failed\n");
-       return -1;
+    if (reg->flags.alloced == 0) {
+       op_addr = get_hook_hva(info);
+    } else {
+       op_addr = (addr_t)V3_VAddr((void *)v3_get_shadow_addr(reg, info->cpu_id, guest_pa));
     }
 
-    return 0;
-}
-
-int v3_handle_mem_full_hook(struct guest_info * info, addr_t guest_va, addr_t guest_pa, 
-                           struct v3_shadow_region * reg, pf_error_t access_info) {
-  
-    addr_t op_addr = get_hook_hva(info);
+    
+    if (access_info.write == 1) { 
+       // Write Operation 
 
-    if (access_info.write == 1) {
        if (v3_emulate_write_op(info, guest_va, guest_pa, op_addr, 
                                reg->write_hook, reg->priv_data) == -1) {
            PrintError("Write Full Hook emulation failed\n");
            return -1;
        }
     } else {
+       // Read Operation
+       
+       if (reg->flags.read == 1) {
+           PrintError("Tried to emulate read for a guest Readable page\n");
+           return -1;
+       }
+
        if (v3_emulate_read_op(info, guest_va, guest_pa, op_addr, 
                               reg->read_hook, reg->write_hook, 
                               reg->priv_data) == -1) {
            PrintError("Read Full Hook emulation failed\n");
            return -1;
        }
+
     }
 
+
     return 0;
 }
 
 
 
+
 struct v3_shadow_region * v3_get_shadow_region(struct v3_vm_info * vm, uint16_t core_id, addr_t guest_addr) {
     struct rb_node * n = vm->mem_map.shdw_regions.rb_node;
     struct v3_shadow_region * reg = NULL;
@@ -377,6 +385,8 @@ struct v3_shadow_region * v3_get_shadow_region(struct v3_vm_info * vm, uint16_t
 }
 
 
+
+
 void v3_delete_shadow_region(struct v3_vm_info * vm, struct v3_shadow_region * reg) {
     int i = 0;
 
@@ -430,8 +440,7 @@ void v3_delete_shadow_region(struct v3_vm_info * vm, struct v3_shadow_region * r
 
 
 addr_t v3_get_shadow_addr(struct v3_shadow_region * reg, uint16_t core_id, addr_t guest_addr) {
-    if ( (reg) && 
-         (reg->host_type != SHDW_REGION_FULL_HOOK)) {
+    if (reg && (reg->flags.alloced == 1)) {
         return (guest_addr - reg->guest_start) + reg->host_addr;
     } else {
        //  PrintError("MEM Region Invalid\n");
@@ -469,8 +478,8 @@ void v3_print_mem_map(struct v3_vm_info * vm) {
                   (void *)(reg->guest_end - 1), 
                   (void *)(reg->host_addr));
 
-       V3_Print("\t(%s) (WriteHook = 0x%p) (ReadHook = 0x%p)\n", 
-                  v3_shdw_region_type_to_str(reg->host_type),
+       V3_Print("\t(flags=%x) (WriteHook = 0x%p) (ReadHook = 0x%p)\n", 
+                  reg->flags.value,
                   (void *)(reg->write_hook), 
                   (void *)(reg->read_hook));
     
@@ -478,21 +487,3 @@ void v3_print_mem_map(struct v3_vm_info * vm) {
     } while ((node = v3_rb_next(node)));
 }
 
-
-static const uchar_t  SHDW_REGION_WRITE_HOOK_STR[] = "SHDW_REGION_WRITE_HOOK";
-static const uchar_t  SHDW_REGION_FULL_HOOK_STR[] = "SHDW_REGION_FULL_HOOK";
-static const uchar_t  SHDW_REGION_ALLOCATED_STR[] = "SHDW_REGION_ALLOCATED";
-
-const uchar_t * v3_shdw_region_type_to_str(v3_shdw_region_type_t type) {
-    switch (type) {
-       case SHDW_REGION_WRITE_HOOK:
-           return SHDW_REGION_WRITE_HOOK_STR;
-       case SHDW_REGION_FULL_HOOK:
-           return SHDW_REGION_FULL_HOOK_STR;
-       case SHDW_REGION_ALLOCATED:
-           return SHDW_REGION_ALLOCATED_STR;
-       default:
-           return (uchar_t *)"SHDW_REGION_INVALID";
-    }
-}
-