Re: [dpdk-dev] [PATCH v13 2/2] eal: support for VFIO-PCI VF token

["Wang, Haiyue" <haiyue.wang@intel.com>]

> -----Original Message-----
> From: Andrew Rybchenko <arybchenko@solarflare.com>
> Sent: Thursday, May 7, 2020 00:51
> To: Wang, Haiyue <haiyue.wang@intel.com>; dev@dpdk.org; Burakov, Anatoly <anatoly.burakov@intel.com>;
> thomas@monjalon.net; jerinj@marvell.com; david.marchand@redhat.com
> Subject: Re: [dpdk-dev] [PATCH v13 2/2] eal: support for VFIO-PCI VF token
> 
> On 5/6/20 2:35 PM, Haiyue Wang wrote:
> > The kernel module vfio-pci introduces the VF token to enable SR-IOV
> > support since 5.7.
> >
> > The VF token can be set by a vfio-pci based PF driver and must be known
> > by the vfio-pci based VF driver in order to gain access to the device.
> >
> > Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
> > Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
> 
> Sorry, lost from my view new versions of the patch series.
> 
> Acked-by: Andrew Rybchenko <arybchenko@solarflare.com>
> 
> > diff --git a/doc/guides/linux_gsg/linux_drivers.rst b/doc/guides/linux_gsg/linux_drivers.rst
> > index 238f3e900..910397243 100644
> > --- a/doc/guides/linux_gsg/linux_drivers.rst
> > +++ b/doc/guides/linux_gsg/linux_drivers.rst
> > @@ -72,11 +72,44 @@ Note that in order to use VFIO, your kernel must support it.
> >  VFIO kernel modules have been included in the Linux kernel since version 3.6.0 and are usually
> present by default,
> >  however please consult your distributions documentation to make sure that is the case.
> >
> > +The ``vfio-pci`` module since Linux version 5.7 supports the creation of virtual
> > +functions. After the PF is bound to vfio-pci module, the user can create the VFs
> > +by sysfs interface, and these VFs are bound to vfio-pci module automatically.
> > +
> > +When the PF is bound to vfio-pci, it has initial VF token generated by random. For
> > +security reason, this token is write only, the user can't read it from the kernel
> > +directly. For accessing the VF, the user needs to start the PF with token parameter
> > +to setup a VF token (uuid format), then the VF can be accessed with this new known
> > +VF token.
> 
> If token is write-only in kernel sysfs, shouldn't we make it
> invisible in ps output? I.e. substitute with something like
> xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.
> It is a bit easier with the new design. Just a thought.
> 

In fact, no sysfs for VF token, just write-only IOCTL. ;-)

> [snip]