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Re: [PATCH v2 1/2] xen/arm: fix iomem permissions cfg in map_range_to_domain()
Hi Grygorii,
On 18/02/2025 11:22, Grygorii Strashko wrote:
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)));
calculates the iomem range end address by rounding it up to the next Xen
page with incorrect assumption that iomem range end address passed to
iomem_permit_access() is exclusive, while it is expected to be inclusive.
It gives Control domain (Dom0) access to manage incorrect MMIO range with
one additional page.
For example, if requested range is [00e6140000:00e6141004] then it expected
to add [e6140:e6141] range (num_pages=2) to the domain iomem_caps rangeset,
but will add [e6140:e6142] (num_pages=3) instead.
To fix it, drop PAGE_ALIGN() from the iomem range end address calculation
formula.
Fixes: 33233c2758345 ("arch/arm: domain build: let dom0 access I/O memory
of mapped devices")
Signed-off-by: Grygorii Strashko <grygorii_strashko@xxxxxxxx>
Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>
Cheers,
---
xen/arch/arm/device.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/xen/arch/arm/device.c b/xen/arch/arm/device.c
index 5610cddcba8e..97e613e06afa 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"
--
Julien Grall
|
