[Qemu-devel] [PATCH] use correct initial region_offset

[Alex Rozenman]

Hi,

I found a bug in phys_page_find_alloc function causing initial region_offset
field to be set to incorrect initial value.
Usually, the pages are re-assigned afterwards, so the bug has very small
effect on regular QEMU users.
We use "memory unassigned" callback and this bug causes invalid addresses
there.

A small patch is attached. I have ssh membership on savannah. Please approve
and/or push.
This is my first time when I am suggesting patches to QEMU; I also would
like to add some fixes for
ppc440/ppc440x6 cores.

-- 
Best regards,
Alex Rozenman (rozen...@gmail.com).

From 8935358ddf9bf5b80c8b8ac7014b650a519a3ebf Mon Sep 17 00:00:00 2001
From: Alex Rozenman <rozen...@gmail.com>
Date: Thu, 27 Jan 2011 12:47:57 +0200
Subject: [PATCH] phys_page_find_alloc: use correct initial region_offset

---
 exec.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/exec.c b/exec.c
index db9ff55..00667d7 100644
--- a/exec.c
+++ b/exec.c
@@ -416,6 +416,7 @@ static PhysPageDesc *phys_page_find_alloc(target_phys_addr_t index, int alloc)
     pd = *lp;
     if (pd == NULL) {
         int i;
+        int first_index = index & ~(L2_SIZE - 1);
 
         if (!alloc) {
             return NULL;
@@ -425,7 +426,7 @@ static PhysPageDesc *phys_page_find_alloc(target_phys_addr_t index, int alloc)
 
         for (i = 0; i < L2_SIZE; i++) {
             pd[i].phys_offset = IO_MEM_UNASSIGNED;
-            pd[i].region_offset = (index + i) << TARGET_PAGE_BITS;
+            pd[i].region_offset = (first_index + i) << TARGET_PAGE_BITS;
         }
     }
 
-- 
1.7.0.4