On Mon, Aug 29, 2011 at 9:13 PM, Avi Kivity <a...@redhat.com> wrote: > On 08/30/2011 12:06 AM, Jan Kiszka wrote: >> >> > >> > Does this need to be save/restored for migration? >> >> Nope, but we need some other measure. I thought to remember the pic was >> refreshing this after load, but I do not find any traces of this now. We >> likely need a post_load handler in the i8259 that re-asserts the IRQ as >> required. >> > > We need some kind of two phase restore. In the first phase all state is > restored; since some of that state drivers outputs that are input to other > devices, they may experience an edge, and we need to supress that. In the > second phase edge detection is unsupressed and the device goes live.
No. Devices may not perform any externally visible activities (like toggle a qemu_irq) during or after load because 1) qemu_irq is stateless and 2) since the receiving end is also freshly loaded, both states are already in synch without any calls or toggling.
