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

[Parav Pandit]

> -----Original Message-----
> From: Alex Williamson <alex.williamson@xxxxxxxxxx>
> Sent: Thursday, August 29, 2019 3:07 AM
> To: Parav Pandit <parav@xxxxxxxxxxxx>
> Cc: Jiri Pirko <jiri@xxxxxxxxxxxx>; kwankhede@xxxxxxxxxx;
> cohuck@xxxxxxxxxx; davem@xxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx
> 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@xxxxxxxxxxxx> 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@xxxxxxxxxxxx>
> >
> > ---
> > 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