[Qemu-devel] Configure virtio-scsi options via libvirt

[Qemu-devel] Configure virtio-scsi options via libvirt

[Mike Perez]

Hi everyone,

I would like be able to configure virtio-scsi options num_queues, max_sectors,
and cmd_per_lun via libvirt. Are there any plans to have this support?

-- 
Mike Perez

Re: [Qemu-devel] Configure virtio-scsi options via libvirt

[Stefan Hajnoczi]

On Tue, May 06, 2014 at 04:13:50PM -0700, Mike Perez wrote:
> I would like be able to configure virtio-scsi options num_queues, max_sectors,
> and cmd_per_lun via libvirt. Are there any plans to have this support?

Hi Mike,
I'm not sure about the status of libvirt support for virtio-scsi options
but in the meantime you can use <qemu:commandline> passthrough:

http://blog.vmsplice.net/2011/04/how-to-pass-qemu-command-line-options.html

Stefan

Re: [Qemu-devel] [libvirt] Configure virtio-scsi options via libvirt

[Ján Tomko]

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On 05/07/2014 01:13 AM, Mike Perez wrote:
> Hi everyone,
> 
> I would like be able to configure virtio-scsi options num_queues, max_sectors,
> and cmd_per_lun via libvirt. Are there any plans to have this support?
> 

num_queues is supported for virtio-scsi controllers since libvirt 1.0.5:

    <controller type='scsi' index='0' model='virtio-scsi'>
      <driver queues='8'/>
    </controller>

http://libvirt.org/git/?p=libvirt.git;a=commit;h=d4bf0a9

Jan


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Re: [Qemu-devel] Configure virtio-scsi options via libvirt

[Mike Perez]

On 10:08 Wed 07 May     , Stefan Hajnoczi wrote:
> On Tue, May 06, 2014 at 04:13:50PM -0700, Mike Perez wrote:
> > I would like be able to configure virtio-scsi options num_queues, max_sectors,
> > and cmd_per_lun via libvirt. Are there any plans to have this support?
> 
> Hi Mike,
> I'm not sure about the status of libvirt support for virtio-scsi options
> but in the meantime you can use <qemu:commandline> passthrough:
> 
> http://blog.vmsplice.net/2011/04/how-to-pass-qemu-command-line-options.html
> 
> Stefan

Thanks Stefan,

My plan is to write the support in OpenStack, which unfortunately does not
accept patches doing qemu passthrough:

http://lists.openstack.org/pipermail/openstack-dev/2013-November/018551.html

-- 
Mike Perez

Re: [Qemu-devel] Configure virtio-scsi options via libvirt

[Paolo Bonzini]

Il 08/05/2014 09:24, Mike Perez ha scritto:
> On 10:08 Wed 07 May     , Stefan Hajnoczi wrote:
>> On Tue, May 06, 2014 at 04:13:50PM -0700, Mike Perez wrote:
>>> I would like be able to configure virtio-scsi options num_queues, max_sectors,
>>> and cmd_per_lun via libvirt. Are there any plans to have this support?
>>
>> Hi Mike,
>> I'm not sure about the status of libvirt support for virtio-scsi options
>> but in the meantime you can use <qemu:commandline> passthrough:
>>
>> http://blog.vmsplice.net/2011/04/how-to-pass-qemu-command-line-options.html
>>
>> Stefan
>
> Thanks Stefan,
>
> My plan is to write the support in OpenStack, which unfortunately does not
> accept patches doing qemu passthrough:
>
> http://lists.openstack.org/pipermail/openstack-dev/2013-November/018551.html

Why do you need such fine-grained control?  The higher you go in the 
stack, the simpler configuration should be in my opinion.

For openstack, I think all you need is a singlequeue vs. multiqueue knob 
(setting num_queues = # VCPUs for multiqueue).

Paolo

Re: [Qemu-devel] [libvirt] Configure virtio-scsi options via libvirt

[Daniel P. Berrange]

On Wed, May 07, 2014 at 10:24:54AM +0200, Ján Tomko wrote:
> On 05/07/2014 01:13 AM, Mike Perez wrote:
> > Hi everyone,
> > 
> > I would like be able to configure virtio-scsi options num_queues, max_sectors,
> > and cmd_per_lun via libvirt. Are there any plans to have this support?
> > 
> 
> num_queues is supported for virtio-scsi controllers since libvirt 1.0.5:

If anyone wants to contribute patches for the other two properties I
would not be a very difficult/large coding job to undertake. I'm not
aware of anyone else who is currently working on it, so anyone please
jump right in...

Regards,
Daniel
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