| | Subject | Re: [Xen-devel] [PATCH 03/10] xen/mmu: Add the notion of IDENTITY_P2M_ENTRY. | | From | Ian Campbell <> | | Date | Wed, 22 Dec 2010 08:44:19 +0000 |
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On Tue, 2010-12-21 at 21:37 +0000, Konrad Rzeszutek Wilk wrote: > P.S. > We cannot set the IDENTITY_P2M_ENTRY in the P2M tree. This is b/c > the toolstack considers that invalid and would abort during > migration of the PV guest. What do we do instead, just write the actual identity MFN value?
Does using 1UL<<30 (or 1UL<<62 on 64 bit, note that Jeremy recently fixed FOREIGN_FRAME_BIT too) as IDENTITY_P2M_ENTRY keep the toolstack happy while still allowing us to distinguish from identity from happens-to-be-the-same as necessary?
To some extent 1-1 I/O regions could be considered foreign mappings (of "memory" owned by DOMIO) so perhaps it's possible that setting the FOREIGN_FRAME_BIT is both sufficient and correct?
Ian.
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