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

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.