Patchwork phys_page_find_alloc: Use correct initial region_offset.

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Submitter Alex_Rozenman@mentor.com
Date Dec. 13, 2011, 10:52 a.m.
Message ID <1323773528-30485-1-git-send-email-Alex_Rozenman@mentor.com>
Download mbox | patch
Permalink /patch/131050/
State New
Headers show

Comments

Alex_Rozenman@mentor.com - Dec. 13, 2011, 10:52 a.m.
From: Alex Rozenman <Alex_Rozenman@mentor.com>

This fixes a common bug with initial region_offset value.
Usually, the pages are re-assigned afterwards, so the bug
has a very small effect on regular QEMU use flows.

Signed-off-by: Alex Rozenman <Alex_Rozenman@mentor.com>
---
 exec.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
Anthony Liguori - Dec. 15, 2011, 6:11 p.m.
On 12/13/2011 04:52 AM, Alex_Rozenman@mentor.com wrote:
> From: Alex Rozenman<Alex_Rozenman@mentor.com>
>
> This fixes a common bug with initial region_offset value.
> Usually, the pages are re-assigned afterwards, so the bug
> has a very small effect on regular QEMU use flows.
>
> Signed-off-by: Alex Rozenman<Alex_Rozenman@mentor.com>

Applied.  Thanks.

Regards,

Anthony Liguori

> ---
>   exec.c |    3 ++-
>   1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/exec.c b/exec.c
> index d8b2180..14628d9 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -418,6 +418,7 @@ 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;
> @@ -427,7 +428,7 @@ 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;
>           }
>       }
>

Patch

diff --git a/exec.c b/exec.c
index d8b2180..14628d9 100644
--- a/exec.c
+++ b/exec.c
@@ -418,6 +418,7 @@  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;
@@ -427,7 +428,7 @@  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;
         }
     }