RE: [PATCH v1 2/5] mdev: Make mdev alias unique among all mdevs

Parav Pandit
2019-08-29T09:08:07Z

> -----Original Message-----
> From: Alex Williamson <alex.williamson@redhat.com>
> Sent: Thursday, August 29, 2019 3:07 AM
> To: Parav Pandit <parav@mellanox.com>
> Cc: Jiri Pirko <jiri@mellanox.com>; kwankhede@nvidia.com;
> cohuck@redhat.com; davem@davemloft.net; kvm@vger.kernel.org; linux-
> kernel@vger.kernel.org; netdev@vger.kernel.org
> Subject: Re: [PATCH v1 2/5] mdev: Make mdev alias unique among all mdevs
>
> On Tue, 27 Aug 2019 14:16:51 -0500
> Parav Pandit <parav@mellanox.com> wrote:
>
> > Mdev alias should be unique among all the mdevs, so that when such
> > alias is used by the mdev users to derive other objects, there is no
> > collision in a given system.
> >
> > Signed-off-by: Parav Pandit <parav@mellanox.com>
> >
> > ---
> > Changelog:
> > v0->v1:
> > - Fixed inclusiong of alias for NULL check
> > - Added ratelimited debug print for sha1 hash collision error
> > ---
> > drivers/vfio/mdev/mdev_core.c | 7 +++++++
> > 1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/vfio/mdev/mdev_core.c
> > b/drivers/vfio/mdev/mdev_core.c index 62d29f57fe0c..4b9899e40665
> > 100644
> > --- a/drivers/vfio/mdev/mdev_core.c
> > +++ b/drivers/vfio/mdev/mdev_core.c
> > @@ -375,6 +375,13 @@ int mdev_device_create(struct kobject *kobj, struct
> device *dev,
> > ret = -EEXIST;
> > goto mdev_fail;
> > }
> > + if (tmp->alias && alias && strcmp(tmp->alias, alias) == 0) {
>
> Nit, test if the device we adding has an alias before the device we're testing
> against. The compiler can better optimize keeping alias hot.
> Thanks,
>
Ok. will do.

> Alex