* Richardson, Bruce (bruce.richardson at intel.com) wrote: > > > > -----Original Message----- > > From: Chris Wright [mailto:chrisw at redhat.com] > > Sent: Friday, June 13, 2014 10:52 AM > > To: Richardson, Bruce; Stephen Hemminger > > Cc: Thomas Monjalon; dev at dpdk.org > > Subject: [PATCH] igb_uio: cap max VFs at 7 to reserve one for PF > > > > To keep from confusing users, cap max VFs at 7, despite PCI SR-IOV config > > space showing a max of 8. This reserves a queue pair for the PF. > > > > This issue was cited here: > > > > http://dpdk.org/ml/archives/dev/2014-April/001832.html > > > > Cc: Bruce Richardson <bruce.richardson at intel.com> > > Cc: Stephen Hemminger <stephen at networkplumber.org> > > Signed-off-by: Chris Wright <chrisw at redhat.com> > > --- > > > > This is what Linux kernel driver does. I have only > > compile tested it. Stephen sending to you and Bruce > > in case you want to Ack and add to your current queue. > > > > Sorry, NAK - at least for this implementation.
Oh, that's fine. > Hardcoding this to 7 is a bad idea, as the actual max number of VFs supported > will depend on the actual hardware used. For someone using an 82599, they can > have up to 64 VFs, or 63+PF, so limiting so 7 in that case is a major > reduction in capability. What might work there is querying the max number of > VFs and limiting to max - 1. But this is igb_uio, not 82599 (ixgbe). > However, even with that, I would suggest that any limit should be possible to > override. It's entirely possible that someone max actually want to reserve > the full number of VFs, either because they don't want to use the NIC on the > host at all, or because they are happy to use a VF on the host instead. > Module parameter to allow override might work - and information on it could > be added to the error message when we limit the VFs inside the driver. It's been a while since I've looked at this, but my recollection is the PF must be there (basic mailbox handling, for example). Would you rather a simple warning message as a hint?
