On Fri, Mar 22, 2013 at 11:27:59AM +1030, Rusty Russell wrote: > "H. Peter Anvin" <hpa@xxxxxxxxx> writes: > > On 03/21/2013 10:49 AM, Michael S. Tsirkin wrote: > >> > >> Just to clarify, I expect BIOS to use it *for config access*. > >> Notification will support IO anyway because it's > >> faster on KVM, so BIOS can use it directly. > >> > > > > Ah, yes, of course. > > > > Quite frankly, I don't see any reason to support *anything else* for > > configuration, does anyone else? > > > > I thought we were talking about the doorbell/notification/kicker > > register. For I/O space especially it is highly desirable if that can > > be in a minimal BAR (4 bytes). > > The takeaway from this seems to be that: > 1) For the notification, device can supply both. > 2) Since only device will know which is faster, driver should use the > first one it finds which it supports. > > My patch implied that the ISR, device config and notification could be > either. I think only the notification makes sense, as noted here. > > Have I got this right? > Rusty. Peter is also saying we need a way to do configuration/ISR without memory accesses. -- MST _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
