> -----Original Message----- > From: Chao Gao [mailto:chao....@intel.com] > Sent: 15 December 2017 00:36 > To: Paul Durrant <paul.durr...@citrix.com> > Cc: Stefano Stabellini <sstabell...@kernel.org>; Wei Liu > <wei.l...@citrix.com>; Andrew Cooper <andrew.coop...@citrix.com>; Tim > (Xen.org) <t...@xen.org>; George Dunlap <george.dun...@citrix.com>; > xen-de...@lists.xen.org; Jan Beulich <jbeul...@suse.com>; Ian Jackson > <ian.jack...@citrix.com> > Subject: Re: [RFC Patch v4 2/8] ioreq: bump the number of IOREQ page to 4 > pages > > On Thu, Dec 14, 2017 at 02:50:17PM +0000, Paul Durrant wrote: > >> -----Original Message----- > >> > > >> > Hmm. That looks like it is because the ioreq server pages are not owned > by > >> > the correct domain. The Xen patch series underwent some changes > later in > >> > review and I did not re-test my QEMU patch after that so I wonder if > >> > mapping IOREQ pages has simply become broken. I'll investigate. > >> > > >> > >> I have reproduced the problem locally now. Will try to figure out the bug > >> tomorrow. > >> > > > >Chao, > > > > Can you try my new branch > http://xenbits.xen.org/gitweb/?p=people/pauldu/xen.git;a=shortlog;h=refs > /heads/ioreq24? > > > > The problem was indeed that the ioreq pages were owned by the > emulating domain rather than the target domain, which is no longer > compatible with privcmd's use of HYPERVISOR_mmu_update. > > Of course. I tested this branch. It works well. > > But, I think your privcmd patch couldn't set 'err_ptr' to NULL when > calling xen_remap_domain_mfn_array(). It works for the ioreq page is > allocated right before the bufioreq page, and then they happen to be > continuous. >
I'll have a look at that. The pages should not need to be contiguous MFNs for things to work. They will, by design, by mapped so that they are virtually contiguous. That's just a convenient way of getting pointers to the buf and synchronous structures in QEMU using only a single IOCTL to privcmd. Paul > Thanks > Chao _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
