Re: [Qemu-devel] [PATCH v2 37/36] qdev: device_del: search for to be unplugged device in 'peripheral' container

[Zhu Guihua]

On Tue, 2014-10-07 at 15:53 +0200, Igor Mammedov wrote:
> On Tue, 07 Oct 2014 15:23:45 +0200
> Andreas Färber <address@hidden> wrote:
> 
> > Am 07.10.2014 um 14:10 schrieb Igor Mammedov:
> > > On Tue, 7 Oct 2014 19:59:51 +0800
> > > Zhu Guihua <address@hidden> wrote:
> > > 
> > >> On Thu, 2014-10-02 at 10:08 +0000, Igor Mammedov wrote:
> > >>> device_add puts every device with 'id' inside of 'peripheral'
> > >>> container using id's value as the last component name.
> > >>> Use it by replacing recursive search on sysbus with path
> > >>> lookup in 'peripheral' container, which could handle both
> > >>> BUS and BUS-less device cases.
> > >>>
> > >>
> > >> If I want to delete device without id inside of 'peripheral-anon'
> > >> container, the command 'device_del' does not work. 
> > >> My suggestion is deleting device by the last component name, is this
> > >> feasiable?
> > > So far device_del was designed to work only with id-ed devices.
> > > 
> > > What's a use-case for unplugging unnamed device from peripheral-anon?
> > 
> > I can think of use cases where you may want to balloon memory or CPUs.
> yep currently initial CPUs are created without dev->id and even without
> device_add help.
> However if/when it's switched to device_add we can make them use
> auto-generated IDs so they would go into peripheral section.
> That would let us keep peripheral-anon for devices that shouldn't
> be unplugged.

when device_add pc-dimm, only 'memdev' property is necessary, but the
'id' property is optional. 

So I execute the command as followings:
object_add memory-backend-ram,id=ram0,size=128M
device_add pc-dimm,memdev=ram0

Now it is impossible to delete the pc-dimm, because it has no id, and it
is inside of 'peripheral-anon' container. 

Regards,
Zhu

> 
> > 
> > But that seems orthogonal to this series.
> > 
> > Regards,
> > Andreas
> > 
>