Re: [libvirt] Support for more than 32 virtio devices
On Tue, May 03, 2011 at 05:31:02PM -0500, Anthony Liguori wrote:
On 05/03/2011 09:33 AM, Daniel P. Berrange wrote:
>On Mon, May 02, 2011 at 08:09:07AM -0700, Badari Pulavarty wrote:
>>Hi,
>>
>>How can I make use of "multifunction" functionality to support
>>more than 32 virtio devices in QEMU through libvirt ?
>
>It isn't supported because it doesn't work with hotplug.
And to be clear, on the QEMU side, we really need to have a high
level modelling of a multifunction device. So the following should
be possible:
-device virtio-blk-pci,ports=4,drive0=hda,drive1=hdb,drive2=hdc,...
Then libvirt could add/remove all ports in a single operation.
Having to add/remove all ports at once is still an undesirable
restriction on mgmt applications, hence the desire for a proper
virtio block controller which allows multiple drives in the
same way as LSI SCSI does today. Once we have the latter I don't
really see much point in using multifunction virtio block.
>>Are there corresponding changes in libvirt ?
>
>To increase the number of devices in a usable manner, we we're waiting
>for QEMU to support either
>
> - A virtio block controller with multiple disks
> - A PCI bridge to allow> 28 PCI devices
Daniel
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