Re: [PATCH v4 02/10] hw/core: create Resettable QOM interface

[Damien Hedde <damien.hedde@greensocs.com>]

On 9/27/19 3:07 PM, Peter Maydell wrote:
> On Tue, 24 Sep 2019 at 12:21, Damien Hedde <damien.hedde@greensocs.com> wrote:
> 
> My takes:
>  * I think we should keep the reset type. Among other things,
>    we probably want a reset type for "PCI bus reset" and
>    "SCSI bus reset", when we come to conversion of those
>  * I don't have an opinion about the phase names
>  * I think we should look at what we're doing for dynamic
>    changes of the reset tree. This falls into two parts,
>    both of which have come up in this thread:
>     - hotplug, ie what state should a hotplugged device
>       get set up to if it's plugged into a bus that's
>       currently in reset
>     - the modification of the qbus tree during reset,
>       like the raspi sd card thing
>    These feel related to me, so maybe handling the first
>    gives a better answer to handling the second ?
> 

Sorry for the delayed answer, I did not had much time to work on this
last week.

Regarding hotplug, right now hotplugged device are reset during the
'realize' step. So here is what I propose:
+ we always do the phase 1 and 2.
+ do the 3rd phase (to leave reset) if the device is not plugged in a
bus under reset.

For general case, like the raspi, it can be handled in set_parent_bus()
qdev function.

Damien