[Qemu-devel] [PATCH] i386: Catch all non-present ptes in cpu_get_phys_page_debug

[Jan Kiszka <jan.kiszka@web.de>]

[ Caused some hair pulling here, until I realized that some supposedly
corrupted page was not the bug I'm looking for, but a bug in the debug
code. ]

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
---
 target-i386/helper.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Index: b/target-i386/helper.c
===================================================================
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -1174,6 +1174,8 @@ target_phys_addr_t cpu_get_phys_page_deb
             page_size = 4096;
             pte = ldq_phys(pte_addr);
         }
+        if (!(pte & PG_PRESENT_MASK))
+            return -1;
     } else {
         uint32_t pde;
 
@@ -1193,10 +1195,10 @@ target_phys_addr_t cpu_get_phys_page_deb
                 /* page directory entry */
                 pte_addr = ((pde & ~0xfff) + ((addr >> 10) & 0xffc)) & env->a20_mask;
                 pte = ldl_phys(pte_addr);
-                if (!(pte & PG_PRESENT_MASK))
-                    return -1;
                 page_size = 4096;
             }
+            if (!(pte & PG_PRESENT_MASK))
+                return -1;
         }
         pte = pte & env->a20_mask;
     }