On Fri, Feb 24, 2012 at 04:21:17PM -0700, Alex Williamson wrote: > When a Status method is provided on a slot, the OSPM evaluates > _STA in response to the device check notify on the slot. This > allows some degree of a handshake between the platform and the > OSPM that the hotplug has been acknowledged. > > In order to implement _STA, we need to know which slots have > devices. A slot with device returns 0x0F, a slot without a > device returns Zero. We get this information from Qemu using > the 0xae08 I/O port register. This was previously the read-side > of the register written to commit a device eject and always > returned 0 on read. It now returns a bitmap of present slots, > so we know that reading 0 means we have and old Qemu and > dynamically modify our SSDT to rename the _STA methods. This > is necessary to allow backwards compatibility. > > The _STA method also writes the slot identifier to I/O port > register 0xae00 as an acknowledgment of the hotplug request.
Thanks. The patch looks fine to me. However, since I'm not all that familiar with the details of the qemu/kvm support for this, I'd like to see an Ack from one of the qemu or kvm maintainers. -Kevin
