[libvirt] [PATCH v2 2/2] qemu: Default to virtio-net where available

[Daniel P. Berrange]

On Wed, Sep 02, 2015 at 04:08:52PM -0400, Laine Stump wrote:
> On 09/02/2015 12:14 PM, Andrea Bolognani wrote:
> >This applies to all architectures except for ARM, which already
> >has its own logic to pick the best default.
> >
> >Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1254044
> >---
> >Changes from v1:
> >
> >   * make sure virtio-net is available using capabilities
> >     instead of blindly using it (thanks Martin)
> >
> >   * change the default for all architectures (except arm)
> >     instead of just ppc64
> 
> Are we certain we want to do this even for x86 guests? I don't think it's a
> good idea - it makes the default into something for which no driver exists
> on the install media for *many* x86 guests, meaning it is highly likely that
> a "default" config would have non-functional networking. AFAIR this is why
> we didn't make virtio the default several years ago when we began recording
> a default into the XML (and why the last time changing the default was
> discussed, I believe it was pointing more towards something like e1000, i.e.
> something which 1) we are certain has a driver on every guest OS
> installation media that might be found, 2) is better maintained in qemu than
> the rtl8139, and 3) performs better than rtl8139 (although obviously not as
> good as virtio).

Agreed, making virtio-net the default is a bad idea because the guest
OS support for it is pretty limited to essentially just modern Linux
guests out of the box. So nack to this patch.


Regards,
Daniel
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