Re: [PATCH 5/5] ixgbe: add driver set_max_vfs support

Yinghai Lu
2012-10-03T20:37:22Z

On Wed, Oct 3, 2012 at 11:47 AM, Alexander Duyck
<alexander.h.duyck@intel.com> wrote:
> The ixgbe_set_max_vfs function has several issues. The two big ones are
> that this function assumes it can just enable/disable SR-IOV without any
> other changes being necessary which is not the case. I would recommend
> looking at ixgbe_setup_tc for how to do this properly. Secondly is the
> fact that this code will change the PF network device and as such
> sections of the code should be called with the RTNL lock held. In
> addition I believe you have to disable SR-IOV before enabling it again
> with a different number of VFs.

yes, agreed.

>
> Below is a link to one of the early patches for igb when we were first
> introducing SR-IOV, and the in-driver sysfs value had been rejected. I
> figure it might be useful as it was also using sysfs to enable/disable
> VFs. It however doesn't have the correct locking on changing the queues
> and as such will likely throw an error if you were to implement it the
> same way now:
> http://lists.openwall.net/netdev/2009/04/08/34

yes, that is almost there if put that in-driver value to per device
value and ops.

Thanks

Yinghai