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Date: Thu, 9 Jan 2014 19:18:21 +0100
From: Hani Benhabiles <kroosec@gmail.com>
Message-ID: <20140109181821.GA4609@Inspiron-3521>
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	<20140108171749.GB3717@Inspiron-3521> <52CD8C09.2070306@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH] qdev: Assign a default device ID when none
 is provided.
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: stefanha@redhat.com, Markus Armbruster <armbru@redhat.com>, qemu-devel@nongnu.org, aliguori@amazon.com, imammedo@redhat.com, afaerber@suse.de

On Wed, Jan 08, 2014 at 06:34:01PM +0100, Paolo Bonzini wrote:
> Il 08/01/2014 18:17, Hani Benhabiles ha scritto:
> > For this reason, the loop in assign_device_name() specifically check that the ID
> > doesn't exist already and uses the next value if it does.
> > 
> > How would something like:
> > (qemu) device_add virtio-net-pci
> > ==> ID: virtio-net-pci.0
> > 
> > Be more problematic than:
> > (qemu) device_add virtio-net-pci,id=virtio-net-pci.0
> 
> (qemu) device_add virtio-net-pci
> (qemu) device_add virtio-net-pci,id=virtio-net-pci.0
> 
> works without your patches, fails with them (IIUC).

It would fail with a clear and descriptive message (Duplicate ID) which is no
different than when a user uses tries to do so manually.

Without the patch, how does a user unplug a device for which he didn't specify
an ID (eg. forgotten, added quickly...)

It is even more confusing with other commands like info networks.

(qemu) device_add virtio-net-pci
(qemu) device_add virtio-net-pci,id=foo
(qemu) info network 
virtio-net-pci.0: index=0,type=nic,model=virtio-net-pci,macaddr=52:54:00:12:34:56
foo: index=0,type=nic,model=virtio-net-pci,macaddr=52:54:00:12:34:57
(qemu) device_del foo
(qemu) device_del virtio-net-pci.0
Device 'virtio-net-pci.0' not found

If the naming scheme is an issue, could something like starting it with one or
two underscores better suited ?

Cheers,

Hani.