Re: [Xen-devel] [PATCH V2] xen/arm: mm: fix nr_second calculation in setup_frametable_mappings

2016-05-16 Thread Wei Liu 
On Mon, May 16, 2016 at 10:36:11AM +0100, Julien Grall wrote:
> (CC Wei for Xen 4.7)
> 
> Hi,
> 
> On 12/05/16 14:03, Peng Fan wrote:
> >On ARM64, "frametable_size >> SECOND_SHIFT" computes the number
> >of second level entries, not the number of second level pages.
> >
> >"ROUNDUP(frametable_size, FIRST_SIZE) >> FIRST_SHIFT" which computes
> >the number of the first level entries (the number of second level pages),
> >is the correct one that should be used.
> >
> >Signed-off-by: Peng Fan 
> >Cc: Stefano Stabellini 
> >Cc: Julien Grall 
> 
> Reviewed-by: Julien Grall 

Release-acked-by: Wei Liu 

___
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

Re: [Xen-devel] [PATCH V2] xen/arm: mm: fix nr_second calculation in setup_frametable_mappings

2016-05-16 Thread Julien Grall 

(CC Wei for Xen 4.7)

Hi,

On 12/05/16 14:03, Peng Fan wrote:

On ARM64, "frametable_size >> SECOND_SHIFT" computes the number
of second level entries, not the number of second level pages.

"ROUNDUP(frametable_size, FIRST_SIZE) >> FIRST_SHIFT" which computes
the number of the first level entries (the number of second level pages),
is the correct one that should be used.

Signed-off-by: Peng Fan 
Cc: Stefano Stabellini 
Cc: Julien Grall 


Reviewed-by: Julien Grall 

This is a bug fix for Xen 4.7 and should be backported up to Xen 4.4.

Wei, could we get a release-ack for this patch?

The computation of the number of page to allocation was wrong. This 
could result to overrun xen_first on platform with big amount of memory.


Regards,

--
Julien Grall

___
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

[Xen-devel] [PATCH V2] xen/arm: mm: fix nr_second calculation in setup_frametable_mappings

2016-05-12 Thread Peng Fan 
On ARM64, "frametable_size >> SECOND_SHIFT" computes the number
of second level entries, not the number of second level pages.

"ROUNDUP(frametable_size, FIRST_SIZE) >> FIRST_SHIFT" which computes
the number of the first level entries (the number of second level pages),
is the correct one that should be used.

Signed-off-by: Peng Fan 
Cc: Stefano Stabellini 
Cc: Julien Grall 
---

V2:
 Take Julien's suggestion in 
http://lists.xen.org/archives/html/xen-devel/2016-05/msg01145.html.
 Refine commit log.

 xen/arch/arm/mm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 0a4f845..5f60aa4 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -767,7 +767,8 @@ void __init setup_frametable_mappings(paddr_t ps, paddr_t 
pe)
 base_mfn = alloc_boot_pages(frametable_size >> PAGE_SHIFT, 32<<(20-12));
 
 #ifdef CONFIG_ARM_64
-nr_second = frametable_size >> SECOND_SHIFT;
+/* Compute the number of second level pages. */
+nr_second = ROUNDUP(frametable_size, FIRST_SIZE) >> FIRST_SHIFT;
 second_base = alloc_boot_pages(nr_second, 1);
 second = mfn_to_virt(second_base);
 for ( i = 0; i < nr_second; i++ )
-- 
2.6.2


___
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel