RE: [PATCH v1 2/2] vfio/mdev: Removed unused and redundant API for mdev UUID

From: Parav Pandit
Date: Wed Aug 07 2019 - 12:33:17 EST




> -----Original Message-----
> From: Cornelia Huck <cohuck@xxxxxxxxxx>
> Sent: Wednesday, August 7, 2019 2:58 PM
> To: Parav Pandit <parav@xxxxxxxxxxxx>
> Cc: kvm@xxxxxxxxxxxxxxx; wankhede@xxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; alex.williamson@xxxxxxxxxx; cjia@xxxxxxxxxx
> Subject: Re: [PATCH v1 2/2] vfio/mdev: Removed unused and redundant API for
> mdev UUID
>
> On Tue, 6 Aug 2019 09:18:26 -0500
> Parav Pandit <parav@xxxxxxxxxxxx> wrote:
>
> > There is no single production driver who is interested in mdev device
> > uuid. Currently UUID is mainly used to derive a device name.
> > Additionally mdev device name is already available using core kernel
> > API dev_name().
>
> Well, the mdev code actually uses the uuid to check for duplicates before
> registration with the driver core would fail... I'd just drop the two sentences
Yes, it does the check. But its mainly used to derive a device name.
And to ensure that there are no two devices with duplicate name, it compares with the uuid.

Even this 16 bytes storage is redundant.
Subsequently, I will submit a patch to get rid of storing this 16 bytes of UUID too.
Because for duplicate name check, device name itself is pretty good enough.

Since I ran out of time and rc-4 is going on, I differed the 3rd simplification patch.

Commit message actually came from the thoughts of 3rd patch, but I see that without it, its not so intuitive.

> talking about the device name, IMHO they don't really add useful information;
> but I'll leave that decision to the maintainers.
>
> >
> > Hence removed unused exported symbol.
> >
> > Signed-off-by: Parav Pandit <parav@xxxxxxxxxxxx>
> > ---
> > Changelog:
> > v0->v1:
> > - Updated commit log to address comments from Cornelia
> > ---
> > drivers/vfio/mdev/mdev_core.c | 6 ------
> > include/linux/mdev.h | 1 -
> > 2 files changed, 7 deletions(-)
>
> Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
Thanks for the review.