[PATCH] xen/arm: fix iomem_ranges cfg in map_range_to_domain()

[Grygorii Strashko <gragst.linux@xxxxxxxxx>]

Now the following code in map_range_to_domain()

res = iomem_permit_access(d, paddr_to_pfn(addr),
                paddr_to_pfn(PAGE_ALIGN(addr + len - 1)));

and

res = rangeset_add_range(mr_data->iomem_ranges,
                         paddr_to_pfn(addr),
                         paddr_to_pfn_aligned(addr + len - 1));

will incorrectly calculate end address of the iomem_range by rounding it up
to the next Xen page, which in turn will give Control domain access to
manage incorrect MMIO range.

For example, requested range:
  00e6140000 - 00e6141004 should set e6140:e6141 nr=2, but will configure
e6140 e6142 nr=3 instead.

Note. paddr_to_pfn_aligned() has PAGE_ALIGN() inside.

Fix it, by using paddr_to_pfn(addr + len - 1) in both places to get correct
end address of the iomem_range.

Signed-off-by: Grygorii Strashko <grygorii_strashko@xxxxxxxx>
---

Hi All,

I have a question - the paddr_to_pfn_aligned() is not used any more,
should I remove it as part of this patch?

 xen/arch/arm/device.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/xen/arch/arm/device.c b/xen/arch/arm/device.c
index 5610cddcba8e..5e1c1cc326ac 100644
--- a/xen/arch/arm/device.c
+++ b/xen/arch/arm/device.c
@@ -71,7 +71,7 @@ int map_range_to_domain(const struct dt_device_node *dev,
                      strlen("/reserved-memory/")) != 0 )
     {
         res = iomem_permit_access(d, paddr_to_pfn(addr),
-                paddr_to_pfn(PAGE_ALIGN(addr + len - 1)));
+                                  paddr_to_pfn(addr + len - 1));
         if ( res )
         {
             printk(XENLOG_ERR "Unable to permit to dom%d access to"
@@ -107,7 +107,7 @@ int map_range_to_domain(const struct dt_device_node *dev,
     {
         res = rangeset_add_range(mr_data->iomem_ranges,
                                  paddr_to_pfn(addr),
-                                 paddr_to_pfn_aligned(addr + len - 1));
+                                 paddr_to_pfn(addr + len - 1));
         if ( res )
             return res;
     }
-- 
2.34.1