On 10 January 2013 12:45, Paolo Bonzini <pbonz...@redhat.com> wrote: > Il 10/01/2013 13:31, Peter Maydell ha scritto: >> On 10 January 2013 12:12, Paolo Bonzini <pbonz...@redhat.com> wrote: >>> It's just an implementation detail. Right now we have a common >>> callback. The idea is to give each bus its own callback. In the case >>> of sysbus it would just call a method; for PCI it would reset some >>> configuration and then call a method; for SCSI there is no need to call >>> a method at all; and so on. >> >> But machine reset shouldn't call bus specific PCI or SCSI reset >> methods -- we've just effectively yanked the power to the VM >> so everything should just reset as if it was freshly constructed. > > Yes, but we do not have a way to do that, so QEMU resorts to a warm reset.
qdev reset is cold reset, not warm reset. >> A bus-specific reset method would be for buses where the bus >> itself has some sort of guest-triggerable reset (by prodding the >> chipset, for instance). > > Yes. > >>> In addition, navigating the qdev tree should be explicit in the methods. >>> It will not happen anymore via the "magic" qdev_reset_all. >> >> *Something* has to say "call reset for every qdev object in the >> system", surely? > > It will call it on sysbus, which will call it on every sysbus child. > Devices that have a child bus will propagate it further down. This doesn't work when we get rid of the idea that every qdev device is attached to a tree of buses. (At this point in the conversation I'm pretty confused about exactly what we're trying to do :-)) -- PMM
