Re: [Qemu-devel] [PATCH for-2.4 1/2] core: reset handler for bus-less devices

[Andreas Färber]

Am 13.07.2015 um 17:38 schrieb Cornelia Huck:
> Really, I think we're moving in circles here. First, the device should
> not live on the sysbus as it does not fit the perceived sysbus
> semantics. As there is no natural bus for it to live on, it becomes a
> pure device. Which is not reset, because somehow a generic callback is
> not called generically.
> 
> I think we're really doing ourselves a disservice by this confused
> calling convention. How likely is it that someone introducing a pure
> device is immediately aware that some callbacks happen automatically
> while others don't? I wouldn't be surprised if there were some
> headscratchers that are solved by adding the reset call.

Well, I'd say the real bug is that this device is on the /machine in the
first place, without a parent that propagates reset. Either it becomes
self-responsible like this patch or my manual alternative are
suggesting, or it is managed by some other object - either by /machine
or indicating that this device is misplaced as a child of /machine.

Fixing qdev reset to automatically propagate to children wouldn't help
here, as /machine is not a device.

I would've suggested putting that on the KVM call agenda, but the call
is not tomorrow but next week.

Regards,
Andreas

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