xen: arm: comment on why 64-bit xen_pfn_t is safe even on 32 bit

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Ian Campbell 2012-10-18 08:26:17 +01:00 committed by Konrad Rzeszutek Wilk
parent 965c0aaafe
commit 3ab0b83bf6

View File

@ -29,7 +29,13 @@
#ifndef __ASSEMBLY__
/* Explicitly size integers that represent pfns in the interface with
* Xen so that we can have one ABI that works for 32 and 64 bit guests. */
* Xen so that we can have one ABI that works for 32 and 64 bit guests.
* Note that this means that the xen_pfn_t type may be capable of
* representing pfn's which the guest cannot represent in its own pfn
* type. However since pfn space is controlled by the guest this is
* fine since it simply wouldn't be able to create any sure pfns in
* the first place.
*/
typedef uint64_t xen_pfn_t;
#define PRI_xen_pfn "llx"
typedef uint64_t xen_ulong_t;