| Message ID | 1463058188-4478-1-git-send-email-van.freenix@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
(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 <van.freenix@gmail.com> > Cc: Stefano Stabellini <sstabellini@kernel.org> > Cc: Julien Grall <julien.grall@arm.com> Reviewed-by: Julien Grall <julien.grall@arm.com> 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,
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 <van.freenix@gmail.com> > >Cc: Stefano Stabellini <sstabellini@kernel.org> > >Cc: Julien Grall <julien.grall@arm.com> > > Reviewed-by: Julien Grall <julien.grall@arm.com> Release-acked-by: Wei Liu <wei.liu2@citrix.com>
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++ )
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 <van.freenix@gmail.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Julien Grall <julien.grall@arm.com> --- 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(-)