>>> On 09.04.18 at 16:10, <chao....@intel.com> wrote: > On Mon, Apr 09, 2018 at 07:40:15AM -0600, Jan Beulich wrote: >>I'm not convinced though that a global option is well suited here: >>Exposing the device in this way may be okay for one guest, but >>not for another. With your model one would need to reboot the >>entire host for such a usage change. >> >>Furthermore boot time specification of SBDF is a problem with the >>Dom0 kernel possibly re-organizing the topology, and is not going >>to work well with hot-plugged devices. > > Point taken. But one concern is if we don't specify devices at boot time > whether PVH dom0 can use such devices (in my understanding, PVH dom0 > will use EPT, it will meet the same issue as HVM domU). If not, we need > treat dom0 as an exception; pages where PBA resides won't be marked as > read-only. But mmio_ro_ranges is global. Maybe build two separate > mmio_ro_ranges for dom0 and domU?
Boot time Dom0 settings can come from the command line. But already for hot-plugged devices (which go to Dom0 as well) this approach would break. Generally permitting Dom0 write access here is certainly an option, but strictly only as long as the MSI-X table won't also become writable. Jan _______________________________________________ Xen-devel mailing list Xenfirstname.lastname@example.org https://lists.xenproject.org/mailman/listinfo/xen-devel