RE: [Bug 55421] igb VF can't work in KVM guest

Williams, Mitch A
2013-03-21T22:03:02Z

Thanks for the FYI, Alex. When we pushed this patch upstream, there was a corresponding patch to igbvf that was pushed at the same time. With this patch, the VFs detect the zero address and generate a random MAC address themselves. The reason for this change is to make the VFs play nicely with udev. The issue was originally raised by Stefan Assmann.

With older drivers in the guest, this will cause the issue you noted. Distros should cherry-pick the corresponding VF patch.

-Mitch

> -----Original Message-----
> From: Alex Williamson [mailto:alex.williamson@redhat.com]
> Sent: Thursday, March 21, 2013 2:32 PM
> To: Williams, Mitch A
> Cc: kvm@vger.kernel.org
> Subject: Re: [Bug 55421] igb VF can't work in KVM guest
>
> Mitch,
>
> Bugzilla wouldn't let me add you to the CC, so FYI...
> Thanks,
>
> Alex
>
> On Thu, 2013-03-21 at 21:29 +0000, bugzilla-daemon@bugzilla.kernel.org
> wrote:
> > https://bugzilla.kernel.org/show_bug.cgi?id=55421
> >
> >
> > Alex Williamson <alex.williamson@redhat.com> changed:
> >
> > What |Removed |Added
> > --------------------------------------------------------------------------
> --
> > CC|
> |alex.williamson@redhat.com,
> > |
> |jeffrey.t.kirsher@intel.com
> >
> >
> >
> >
> > --- Comment #4 from Alex Williamson <alex.williamson@redhat.com> 2013-03-
> 21 21:29:09 ---
> > Further bisected to:
> >
> > commit 5ac6f91d39e0884813dc010e14552143cd1d0d8b
> > Author: Mitch A Williams <mitch.a.williams@intel.com>
> > Date: Fri Jan 18 08:57:20 2013 +0000
> >
> > igb: Don't give VFs random MAC addresses
> >
> > If the user has not assigned a MAC address to a VM, then don't give it
> a
> > random one. Instead, just give it zeros and let it figure out what to
> do
> > with them.
> >
> > Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
> > CC: Andy Gospodarek <andy@greyhouse.net>
> > CC: Stefan Assmann <sassmann@kpanic.de>
> > Tested-by: Aaron Brown <aaron.f.brown@intel.com>
> > Tested-by: Stefan Assmann <sassmann@redhat.com>
> > Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
> >
> > So, for whatever reason we no longer assign a random MAC address when
> using the
> > device in a VM (but we do still use one if attached to igbvf in the host).
> I
> > expect we'll eventually see this on all the Intel SR-IOV NICs. The
> solution is
> > to use the ip command to assign the VF a valid MAC address prior to using
> it
> > with KVM. I'll let those who made the change defend it further if they
> wish.
> >
>
>