From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([208.118.235.92]:38305)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <fred.konrad@greensocs.com>) id 1Tj51b-0005o1-Qt
	for qemu-devel@nongnu.org; Thu, 13 Dec 2012 04:24:16 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <fred.konrad@greensocs.com>) id 1Tj51W-0005Fa-HC
	for qemu-devel@nongnu.org; Thu, 13 Dec 2012 04:24:15 -0500
Received: from greensocs.com ([87.106.252.221]:53070
	helo=s15328186.onlinehome-server.info)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <fred.konrad@greensocs.com>) id 1Tj51W-0005FS-Ac
	for qemu-devel@nongnu.org; Thu, 13 Dec 2012 04:24:10 -0500
Message-ID: <50C99EB5.6090808@greensocs.com>
Date: Thu, 13 Dec 2012 10:24:05 +0100
From: =?UTF-8?B?S09OUkFEIEZyw6lkw6lyaWM=?= <fred.konrad@greensocs.com>
MIME-Version: 1.0
References: <1355157952-2321-1-git-send-email-fred.konrad@greensocs.com>
	<1355157952-2321-8-git-send-email-fred.konrad@greensocs.com>
	<CAFEAcA8rEg2S84Pz=pZ5FvvRdJbwwp8o-fAxVGne6_eN7LXstQ@mail.gmail.com>
	<50C8C4A2.7010709@suse.de>
	<CAFEAcA8264ymxVZKTbBQeGT_h1HSMgRscn6wyOFHQ3fnKYG-Ag@mail.gmail.com>
In-Reply-To: <CAFEAcA8264ymxVZKTbBQeGT_h1HSMgRscn6wyOFHQ3fnKYG-Ag@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: quoted-printable
Subject: Re: [Qemu-devel] [RFC PATCH v7 7/8] virtio-pci-blk : Switch to new
	API.
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: aliguori@us.ibm.com, e.voevodin@samsung.com, "Michael S. Tsirkin" <mst@redhat.com>, mark.burton@greensocs.com, qemu-devel@nongnu.org, Alexander Graf <agraf@suse.de>, stefanha@redhat.com, cornelia.huck@de.ibm.com, Paolo Bonzini <pbonzini@redhat.com>, =?UTF-8?B?QW5kcmVhcyBGw6RyYmVy?= <afaerber@suse.de>

On 12/12/2012 18:58, Peter Maydell wrote:
> On 12 December 2012 17:53, Andreas F=C3=A4rber <afaerber@suse.de> wrote=
:
>> Am 12.12.2012 15:25, schrieb Peter Maydell:
>>> How will the PCI transport's PCI vendor/device/class IDs be
>>> set (a) when a virtio-blk backend is created and separately
>>> plugged into a virtio-pci transport (b) for the legacy
>>> virtio-pci-blk? [ideally the answer to (b) should be "in the
>>> same way as for (a)"]
>> The obvious answer would be that PCI properties need to be set on the
>> PCI device, not an a VirtioDevice sitting on a virtio-bus.
>>
>> I.e., with the proposed refactoring we'd have on the virtio-bus:
>>
>> - VirtioDevice
>>    + VirtioBlockDevice
>>    + VirtioSCSIDevice - has-a scsi-bus
>>    ...
>>
>> In turn that means that every VirtioDevice to be exposed as PCI device
>> to the guest needs it own PCIDevice exposing a private virtio-bus.
>>
>> - PCIDevice
>>    - VirtioPCIDevice - has-a virtio-bus
>>      + virtio-blk-pci - has-a VirtioBlockDevice on its virtio-bus
>>      + virtio-scsi-pci - has-a VirtioSCSIDevice on its virtio-bus
>>      ...
> ...this bit is only for legacy back-compat. It should be equally
> valid to just use the PCI transport plugged into a VirtioDevice,
> both of which were created by the user with -device [and for
> new transports, separate transport and backend should be the
> standard]. That means the virtio-bus interface needs a way for
> the backend to announce to the transport what it is so that
> the PCI transport can set the right PCI IDs.
>
> -- PMM
Yes, it's done with uint16_t get_virtio_device_id(VirtioBusState *bus)=20
function from second step.