[libvirt-users] sr-vio on intel while virsh chooses rtl8139 for model type

Laine Stump laine at laine.org
Wed Oct 8 14:41:25 UTC 2014

On 10/08/2014 03:35 AM, lejeczek wrote:
> On 03/10/14 17:15, Laine Stump wrote:
>> On 10/03/2014 11:38 AM, lejeczek wrote:
>>> hi everybody
>>> I'd presume virsh makes the best possible choice, right?
>>> It is that just seems bit... odd having realtek in guest and Intel's
>>> VF on host, no?
>> This can safely be ignored - in the case of an SRIOV VF that is assigned
>> to the guest using PCI passthrough device assignment, the "model"
>> attribute is meaningless, but libvirt will always fill in the default
>> value (which is rtl8139) in the XML to prevent surprises if the default
>> emulated NIC model ever changes.
>> (I am assuming that you're using either <interface type='hostdev'> or
>> <interface type='network'> pointint to a network that has <forward
>> mode='hostdev'>. If you are instead using "type='direct'" or a network
>> with "<forward mode='bridge|passthrough|vepa'>" then the model *does*
>> matter, and you probably want to set it to "virtio", which is *not* the
>> default because not all guest OSes have a virtio network driver by
>> default (e.g. MS Windows))
> I don't use forward (unless libvirt does that for me) but I have a
> pool like this one:

This does not show the details of your network. For that, you would need
to get the output of "virsh net-dumpxml passpool-enp2s0f0".

If, as you have indicated in your next message, the guest sees the same
hardware type as what is physically on the host, then you are using
<forward mode='hostdev'> in your network (and no, libvirt would not "do
that for you", you or someone else would have needed to configure the
network "passpool-enp2s0f0" in that way).

> <interface type='network'>
>       <mac address='52:54:00:51:af:0e'/>
>       <source network='passpool-enp2s0f0'/>
>       <model type='rtl8139'/>
>       <address type='pci' domain='0x0000' bus='0x00' slot='0x07'
> function='0x0'/>
>     </interface>
> In a win 2008 guest OS is missing drivers for this device and I wonder
> what is that it gets?

More information about the libvirt-users mailing list