Tian, Kevin
2006-Jan-25 01:28 UTC
RE: [Xen-ia64-devel] RE: [Xen-devel] VP problematic for backend driverson IA64?
>From: Magenheimer,Dan (HP Labs Fort Collins) >Sent: 2006年1月25日 8:03 >[...] >Do hardware IOMMU''s in general handle this complication? >E.g. is there a cleanly defined interface that can be applied >to a VP domain "Xen IOMMU"?If drivers conform to DMA interface, that''s the cleanly defined one. Thanks, Kevin> >Dan > >> -----Original Message----- >> From: Ian Pratt [mailto:m+Ian.Pratt@cl.cam.ac.uk] >> Sent: Tuesday, January 24, 2006 4:43 PM >> To: Muli Ben-Yehuda; Magenheimer, Dan (HP Labs Fort Collins) >> Cc: xen-devel; okrieg@us.ibm.com; ian.pratt@cl.cam.ac.uk >> Subject: RE: [Xen-devel] VP problematic for backend drivers on IA64? >> >> >> > I understand that during the IA64 session at the summit there >> > was some discussion on VP being problematic for the current >> > backend drivers (or the other way around), and IOMMUs were >> > suggested as a possible solution. Could you please elaborate >> > on what''s the problem? >> >> It''s simply that the actual DMA operations need to use machine >> addresses. Ideally, you''d use an iommu to translate/partition, but in >> the absence of an iommu simply enabling a privileged domain >> to read its >> p2m table and translate the pfn to an mfn is sufficient. >> >> Ian >> > >_______________________________________________ >Xen-ia64-devel mailing list >Xen-ia64-devel@lists.xensource.com >http://lists.xensource.com/xen-ia64-devel_______________________________________________ Xen-ia64-devel mailing list Xen-ia64-devel@lists.xensource.com http://lists.xensource.com/xen-ia64-devel