On Tue, Jun 11, 2013 at 11:18:13AM +0300, Michael S. Tsirkin wrote: > On Tue, Jun 11, 2013 at 10:00:36AM +0200, Gerd Hoffmann wrote: > > Hi, > > > > > Yes and not just because of windows guests. > > > ACPI spec is also very explicit that native hotplug is an optional > > > feature. Test suites such as WHQL are known to test spec compliance. > > > > /me looks a bit surprised. > > > > This pretty much implies that any shpc bridge needs a second interface > > to the hotplug functionality which can be driven via ACPI. Or the > > firmware somehow handles this using smm (not sure this works for the IRQ > > though). > > > > Do you know how this is handled by real hardware? > > > > cheers, > > Gerd > > SHPC is not very widely deployed on a PC. > > Since most hardware vendors do care about windows support, > the only way is a separate interface that is driven via ACPI. > You then need an ACPI specific register to switch to standard SHPC. > The SHPC spec even tells you as much.
Just to give another example, interface in this patch scales trivially to multi-root configurations, if we ever want to support them. > -- > MST
