Re: [Qemu-devel] [PATCH 00/15] qdev: make reset semantics more clear and consistent, reset qbuses under virtio devices

[Paolo Bonzini]

Il 10/01/2013 12:59, Peter Maydell ha scritto:
>>>>> >>> > It's possible.  I'll move the SCSI bus away from qdev reset.
>>>>> >>> > Anthony/Michael, can you help doing the same with PCIDevice?  And
>>>>> >>> > perhaps Peter and Andreas with sysbus?
>>> >> What does it even mean to reset a sysbus? Do we do it anywhere?
>>> >> (it looks like vl.c does, just as a shortcut so memory mapped devices
>>> >> get their reset hooks called?)
> So how should it work instead? I kind of feel like all qdev devices should
> get their reset hook called on machine reset, regardless of bus [since it's
> modelling power cycling the whole system], but would that break
> something?

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.

In addition, navigating the qdev tree should be explicit in the methods.
 It will not happen anymore via the "magic" qdev_reset_all.

Paolo