> -----Original Message----- > From: Jan Beulich [mailto:jbeul...@suse.com] > Sent: 12 September 2018 10:13 > To: Paul Durrant <paul.durr...@citrix.com> > Cc: George Dunlap <george.dun...@citrix.com>; Kevin Tian > <kevin.t...@intel.com>; xen-devel <xen-devel@lists.xenproject.org> > Subject: RE: [PATCH v6 08/14] vtd: add lookup_page method to iommu_ops > > >>> On 12.09.18 at 11:05, <paul.durr...@citrix.com> wrote: > >> From: Jan Beulich [mailto:jbeul...@suse.com] > >> Sent: 12 September 2018 10:03 > >> > >> A HVM guest using the PV IOMMU is quite fine, but it shouldn't talk to > >> it in terms of MFNs. > >> > > > > Well, it has to talk MFNs at some level, surely? The output of the IOMMU is > > not subject to EPT/NPT, right? > > Yes to the second question, but no to the first: The GFN -> MFN translation > should still be done inside Xen in the HVM case, imo (in the course of > manufacturing the PTE).
Indeed. This function is very much internal to Xen (it's simply an abstraction on top of a vendor implementation), so why should it not work in terms of MFNs? There's no hypercall that allows this to be blindly called by an HVM guest. Paul > > Jan > _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
