Re: [dpdk-dev] vfio detection

["Richardson, Bruce" <bruce.richardson@intel.com>]

> -----Original Message-----
> From: Burakov, Anatoly
> Sent: Wednesday, June 18, 2014 4:01 AM
> To: Richardson, Bruce; dev@dpdk.org
> Subject: RE: vfio detection
> 
> Hi Bruce,
> 
> > > > I have a number of NIC ports which were working correctly yesterday
> > > > and are bound correctly to the igb_uio driver - and I want to keep
> > > > using them through the igb_uio driver for now, not vfio. However,
> > > > whenever I run a dpdk application today, I find that the vfio kernel
> > > > module is getting loaded each time - even after I manually remove
> > > > it, and verify that it has been removed by checking lsmod. Is this
> > > > expected? If so, why are we loading the vfio driver when I just want to
> > continue using igb_uio which works fine?
> > >
> > > Can you elaborate a bit on what do you mean by "loading vfio driver"?
> > > Do you mean the vfio-pci kernel gets loaded by DPDK? I certainly
> > > didn't put in any code that would automatically load that driver, and
> > certainly not binding devices to it.
> >
> > The kernel module called just "vfio" is constantly getting reloaded, and there
> > is always a "/dev/vfio" directory, which triggers the vfio code handling every
> > time I run dpdk.
> 
> I can't reproduce this.
> 
> Please note that VFIO actually consists of three drivers (on an x86 system, that
> is) - vfio (the core VFIO infrastructure such as containers), vfio_iommu_type1
> (support for x86-style IOMMU) and vfio-pci (the generic PCI driver). I have
> unloaded all three and ran dpdk_nic_bind and testpmd - it worked fine and no
> VFIO kernel drivers were loaded as a result.
> 
Ok, maybe a one-off. The proposed patches to dpdk to improve the detection of vfio fix the real issue for me anyway, so I'm no longer concerned.