>>> On 25.06.15 at 15:36, <paul.durr...@citrix.com> wrote: > I think that also allows me to simplfy the patch since I don't have to > modify the mmio_check op any more. I simply call it once for the first byte > of the access and, if it accepts, verify that it also accepts the last byte > of the access.
That's actually not (generally) okay: There could be a hole in the middle. But as long as instructions don't do accesses wider than a page, we're fine with that in practice I think. Or wait, no, in the MSI-X this could not be okay: A 64-byte read to the 16 bytes 32 bytes away from a page boundary (and being the last entry on one device's MSI-X table) would extend into another device's MSI-X table on the next page. I.e. first and last bytes would be okay to be accessed, but bytes 16...31 of the access wouldn't. Of course the MSI-X read/write handlers don't currently permit such wide accesses, but anyway... Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel