>>> On 21.01.19 at 12:56, <paul.durr...@citrix.com> wrote: >> -----Original Message----- >> From: Jan Beulich [mailto:jbeul...@suse.com] >> Sent: 21 January 2019 11:28 >> To: Paul Durrant <paul.durr...@citrix.com> >> Cc: Julien Grall <julien.gr...@arm.com>; Andrew Cooper >> <andrew.coop...@citrix.com>; Roger Pau Monne <roger....@citrix.com>; Wei >> Liu <wei.l...@citrix.com>; Sander Eikelenboom <li...@eikelenboom.it>; >> George Dunlap <george.dun...@citrix.com>; Ian Jackson >> <ian.jack...@citrix.com>; Chao Gao <chao....@intel.com>; Jun Nakajima >> <jun.nakaj...@intel.com>; Kevin Tian <kevin.t...@intel.com>; Stefano >> Stabellini <sstabell...@kernel.org>; xen-devel <xen- >> de...@lists.xenproject.org>; Konrad Rzeszutek Wilk >> <konrad.w...@oracle.com>; Tim (Xen.org) <t...@xen.org> >> Subject: Re: [PATCH] iommu: specify page_count rather than page_order to >> iommu_map/unmap()... >> >> >>> On 18.01.19 at 17:03, <paul.durr...@citrix.com> wrote: >> > ...and remove alignment assertions. >> > >> > Testing shows that certain callers of iommu_legacy_map/unmap() specify >> > order > 0 ranges that are not order aligned thus causing one of the >> > IS_ALIGNED() assertions to fire. >> >> As said before - without a much better explanation of why the current >> order-based model is unsuitable (so far I've been provided only vague >> pointers into "somewhere in PVH Dom0 boot code" iirc) to understand >> why it's undesirable to simply make those call sites obey to the current >> requirements, I'm not happy to see us go this route. > > I thought... > > "Using a count actually makes more sense because the valid > set of mapping orders is specific to the IOMMU implementation and to it > should be up to the implementation specific code to translate a mapping > count into an optimal set of mapping orders (when the code is finally > modified to support orders > 0)." > > ...was reasonably clear. Is that not a reasonable justification? What else > could I say?
Well, I was hoping to be pointed at the (apparently multiple) call sites where making them match the current function pattern is more involved and/or less desirable than changing the functions here. Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
