RE: VFs go missing with latest kernel

[Rose, Gregory V]

> -----Original Message-----
> From: Rose, Gregory V
> Sent: Tuesday, January 31, 2012 5:03 PM
> To: David Ahern
> Cc: LKML
> Subject: RE: VFs go missing with latest kernel
> 
> > -----Original Message-----
> > From: David Ahern [mailto:daahern@xxxxxxxxx]
> > Sent: Tuesday, January 31, 2012 4:50 PM
> > To: Rose, Gregory V
> > Cc: LKML
> > Subject: Re: VFs go missing with latest kernel
> >
> > On 01/31/2012 05:43 PM, Rose, Gregory V wrote:
> > >>
> > >> Back to the missing VF problem: reverting the patch I mentioned
> before
> > >> and my VM boots up fine with the even-numbered VFs assigned to it.
> > >
> > > OK, thanks... I was staring at the dmesg output you sent me and it is
> > odd because the even numbered VFs that go missing are there when you set
> > their MAC addresses.  See output below the dotted line after my reply.
> >
> > Ah, I think I confused you. The VFs for the first 2 ports (ie., the
> > first 14 VFs) are seen fine; I only showed the VFs for the second 2
> > ports -- which are missing the even number.
> >
> > So, in summary I am missing 7 VFs all associated with the even numbers
> > on the last ports of a quad port card.
> 
> OK, thanks for the clarification.  But it still shows that all 28 VFs
> exist while their MAC addresses are being set but then at some point
> subsequent to that 7 of them on the port belonging to PCI device 07:00.0
> disappear for some reason.
> 
> I'll see what I can find.

I found this in the log file you sent me.  I had missed it yesterday.

[   15.835223] igb 0000:07:00.0: 7 pre-allocated VFs found - override max_vfs setting of 7
[   15.835393] igb 0000:07:00.0: 7 VFs allocated

I think that must be a bug in the code that searches for VFs already allocated and is the source of your problem.  I'll keep you updated on what I find but it has to be a bug in the VF device lookups.

- Greg

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