On Wed, 2016-02-03 at 10:29 +0100, Gerd Hoffmann wrote: > On Di, 2016-02-02 at 13:09 -0700, Alex Williamson wrote: > > This is provided via a device specific region, look for it on Intel > > VGA class devices. Our default mechanism to expose this to the BIOS > > is via fw_cfg where it's expected that the BIOS will copy the data > > into a reserved RAM area and update the ASL Storage register to > > reference the GPA of that buffer. > > > We also support directly mapping > > the OpRegion through to the host in response to the ASL Storage > > register write, which makes the data "live" and potentially provides > > write access should the underlying vfio region support writes. > > This should better be splitted into a separate patch.
Ok. Perhaps I'll drop it for now and make the kernel-level vfio code expose the OpRegion as read-only as a start. It's easy enough to dig out of the mail archives and add back later if we want. > > This > > option is automatically enabled if we somehow don't support fw_cfg (is > > this a good idea?). > > I think this can't happen. And even in case it can: we have bigger > problems than the opregion then. A few of the other fw_cfg_find() users seem to handle the error case, which is why I ask. Thanks, Alex
