RE: VFs go missing with latest kernel

From: Rose, Gregory V
Date: Wed Feb 01 2012 - 13:09:33 EST

> -----Original Message-----
> From: David Ahern [mailto:daahern@xxxxxxxxx]
> Sent: Wednesday, February 01, 2012 9:58 AM
> To: Rose, Gregory V
> Cc: 'LKML'
> Subject: Re: VFs go missing with latest kernel
> On 02/01/2012 10:47 AM, Rose, Gregory V wrote:
> > 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.
> Confused. What is pre-allocating the VFs during boot? Looking at my
> rc-scripts I am only set MAC addresses at boot. No VMs have been started
> yet. This setup has worked fine with Fedora 14 and 3.0 kernels; it's
> really the move to 3.3-rc that I hit the problem.

Nothing is pre-allocating the VFs. That is the bug, the function I wrote to find pre-allocated VFs is messed up somehow. Since it (mistakenly) thinks it's already found pre-allocated VFs, it doesn't call pci_enable_sriov() to allocate them.

- Greg

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