> -----Original Message----- > From: Jan Beulich [mailto:jbeul...@suse.com] > Sent: 14 December 2017 13:46 > To: Paul Durrant <paul.durr...@citrix.com> > Cc: Julien Grall <julien.gr...@arm.com>; Andrew Cooper > <andrew.coop...@citrix.com>; George Dunlap > <george.dun...@citrix.com>; Ian Jackson <ian.jack...@citrix.com>; Wei Liu > <wei.l...@citrix.com>; Stefano Stabellini <sstabell...@kernel.org>; xen- > de...@lists.xenproject.org; Tim (Xen.org) <t...@xen.org> > Subject: Re: [PATCH v14 06/11] x86/hvm/ioreq: add a new mappable > resource type... > > >>> On 14.12.17 at 10:51, <paul.durr...@citrix.com> wrote: > >> From: Paul Durrant [mailto:paul.durr...@citrix.com] > >> Sent: 28 November 2017 15:09 > >> +static int hvm_alloc_ioreq_mfn(struct hvm_ioreq_server *s, bool buf) > >> +{ > >> + struct domain *currd = current->domain; > >> + struct hvm_ioreq_page *iorp = buf ? &s->bufioreq : &s->ioreq; > >> + > >> + if ( iorp->page ) > >> + { > >> + /* > >> + * If a guest frame has already been mapped (which may happen > >> + * on demand if hvm_get_ioreq_server_info() is called), then > >> + * allocating a page is not permitted. > >> + */ > >> + if ( !gfn_eq(iorp->gfn, INVALID_GFN) ) > >> + return -EPERM; > >> + > >> + return 0; > >> + } > >> + > >> + /* > >> + * Allocated IOREQ server pages are assigned to the emulating > >> + * domain, not the target domain. This is because the emulator is > >> + * likely to be destroyed after the target domain has been torn > >> + * down, and we must use MEMF_no_refcount otherwise page > allocation > >> + * could fail if the emulating domain has already reached its > >> + * maximum allocation. > >> + */ > >> + iorp->page = alloc_domheap_page(currd, MEMF_no_refcount); > > > > This is no longer going to work as it is predicated on my original > > modification to HYPERVISOR_mmu_update (which allowed a PV domain to > map a > > foreign MFN from a domain over which it had privilege as if the MFN was > > local). Because that mechanism was decided against, this code needs to > change > > to use the target domain of the ioreq server rather than the calling domain. > > I will verfy this modification and submit v15 of the series. > > > > Jan, are you ok for me to keep your R-b? > > This is all pretty fragile - better drop it and I'll then take a look > once you've sent the new version.
Ok. Will do. Paul > > Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
