add more permission checks to shadow paging

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 c0ce265..6eca4d5 100644 (file)
--- a/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_32.h
+++ b/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_32.h
@@ -389,7 +389,7 @@ static int handle_pte_shadow_pagefault_32(struct guest_info * info, addr_t fault
                PrintError("Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
                return -1;
            }
-       } else {
+       } else if (shdw_reg->flags.write == 1) {
            PrintDebug("Shadow PTE Write Error\n");
            shadow_pte->writable = guest_pte->writable;
        }

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 c3d2964..287b14c 100644 (file)
--- a/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_64.h
+++ b/palacios/src/palacios/mmu/vmm_shdw_pg_swapbypass_64.h
@@ -500,7 +500,7 @@ static int handle_pte_shadow_pagefault_64(struct guest_info * info, addr_t fault
                PrintError("Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
                return -1;
            }
-       } else {
+       } else if (shdw_reg->flags.write == 1) {
            PrintDebug("Shadow PTE Write Error\n");
            shadow_pte->writable = guest_pte->writable;
        }

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 91ae34e..30acc7a 100644 (file)
--- a/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_32.h
+++ b/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_32.h
@@ -274,8 +274,6 @@ static int handle_pte_shadow_pagefault_32(struct guest_info * info, addr_t fault
            }
 
 
-
-           // Write hooks trump all, and are set Read Only
            if (shdw_reg->flags.write == 0) {
                shadow_pte->writable = 0;
            }
@@ -296,7 +294,7 @@ static int handle_pte_shadow_pagefault_32(struct guest_info * info, addr_t fault
                PrintError("Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
                return -1;
            }
-       } else {
+       } else if (shdw_reg->flags.write == 1) {
            PrintDebug("Shadow PTE Write Error\n");
            shadow_pte->writable = guest_pte->writable;
        }

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 cdbb580..df44714 100644 (file)
--- a/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_64.h
+++ b/palacios/src/palacios/mmu/vmm_shdw_pg_tlb_64.h
@@ -500,7 +500,7 @@ static int handle_pte_shadow_pagefault_64(struct guest_info * info, addr_t fault
                PrintError("Special Page fault handler returned error for address: %p\n",  (void *)fault_addr);
                return -1;
            }
-       } else {
+       } else if (shdw_reg->flags.write == 1) {
            PrintDebug("Shadow PTE Write Error\n");
            shadow_pte->writable = guest_pte->writable;
        }