On Wed, Apr 04, 2012 at 11:51:00PM -0600, Alex Williamson wrote: > We've been batting this one back and forth. This series includes > several of the cleanups and specification clarifications from my > series awhile back. Patch 5 is my proposed alternative to > Michael's PCI hotplug race fix. Since that version I added slot > present tracking so we can be a little more strategic about which > slots we ask the guest to check. The approach for that path is > described in the commit log. I tested hotplug on both Linux an > Windows guests (XP + 2k8), intentionally trying to do back to back > device_add and device_del to get a race, but couldn't (I did > however get a glibc double free that seems unrelated to this > series). > > Long term I'd like to deprecate the up/down PCI hotplug interface > and move to a new model. I think perhaps we should define 3 new > registers: > > 1) Device present in slot bitmap (foundation already in 5/5 here) > 2) Virtual slot power state bitmap > 3) Requested slot date bitmap > > With these we should be able to do proper _STA, _PS0, and _PS3. > We'd maintain the eject register for _EJ0, but deprecate up/down.
What problem are you trying to address by doing so? What is the need for power control? Clearly there is no advantage in powering down a virtual device.
