Messages in this thread | | | Subject | Re: [Xen-devel] [PATCH] xen: grant-table: Check truncation when giving access to a frame | From | Julien Grall <> | Date | Mon, 13 Jun 2016 12:10:03 +0100 |
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Hi David,
On 13/06/16 11:57, David Vrabel wrote: > On 13/06/16 11:50, Julien Grall wrote: >> The version 1 of the grant-table protocol only supports frame encoded on >> 32-bit. >> >> When the platform is supporting 48-bit physical address, the frame will >> be encoded on 36-bit which will lead a truncation and give access to >> the wrong frame. >> >> On ARM Xen will always allow the guest to use all the physical address, >> although today the RAM is always located under 40-bits (see >> xen/include/public/arch-arm.h). >> >> Add a truncation check in gnttab_update_entry_v1 to prevent the guest to >> give access to the wrong frame. > > In hindsight, we shouldn't have dropped the V2 support from Linux. > Should we reinstate it?
What were the reasons to drop the v2 support from Linux? More importantly why people did choose to stay on v1?
Cheers,
-- Julien Grall
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