> -----Original Message----- > From: Julien Grall [mailto:julien.gr...@arm.com] > Sent: 26 September 2018 11:41 > To: Jan Beulich <jbeul...@suse.com>; Paul Durrant > <paul.durr...@citrix.com> > Cc: Andrew Cooper <andrew.coop...@citrix.com>; Roger Pau Monne > <roger....@citrix.com>; Stefano Stabellini <sstabell...@kernel.org>; xen- > devel <xen-devel@lists.xenproject.org> > Subject: Re: IOREQ server on Arm > > Hi Jan, > > On 09/26/2018 09:08 AM, Jan Beulich wrote: > >>>> On 26.09.18 at 00:39, <julien.gr...@arm.com> wrote: > >> Hi Paul, > >> > >> I am looking at porting the IOREQ server infrastructure on Arm. I > didn't > >> need much modification to make it run for Arm. Although, the > >> implementation could be simplified over the x86 implementation. > >> > >> I noticed some issue while trying to implement the hypercall > >> XENMEM_acquire_resource. Per my understanding, all the page mapped via > >> that hypercall will use the type p2m_mapping_foreign. > >> > >> This will result to trigger the ASSERT(fdom != dom) in > get_page_from_gfn > >> (asm-arm/p2m.h) because the IOREQ page has been allocated to the > >> emulator domain and mapped to it. AFAICT x86 has the same assert in > >> p2m_get_page_from_gfn(...). > >> > >> IHMO, the ASSERT makes sense because you are only meant to map page > >> belonging to other domain with that type. > >> > >> So I am wondering whether IOREQ server running in PVH Dom0 has been > >> tested? What would be the best course of action to fix the issue? > > > > I think the p2m type needs to be chosen based on > > XENMEM_rsrc_acq_caller_owned. > > I am thinking to introduce p2m_mapping_owned. Or do we have a p2m_type > that we could re-use? >
I think we should be able to just use p2m_ram_rw if it is caller owned. Paul > Cheers, > > -- > Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
