Re: [PATCH 31/34] vfio/mdev: Remove mdev_parent_ops dev_attr_groups

From: Kirti Wankhede
Date: Tue Apr 12 2022 - 17:04:40 EST




On 4/11/2022 7:44 PM, Christoph Hellwig wrote:
From: Jason Gunthorpe <jgg@xxxxxxxxxx>

This is only used by one sample to print a fixed string that is pointless.

In general, having a device driver attach sysfs attributes to the parent
is horrific. This should never happen, and always leads to some kind of
liftime bug as it become very difficult for the sysfs attribute to go back
to any data owned by the device driver.

Remove the general mechanism to create this abuse.

Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/vfio/mdev/mdev_sysfs.c | 12 ++----------
include/linux/mdev.h | 2 --
samples/vfio-mdev/mtty.c | 30 +-----------------------------
3 files changed, 3 insertions(+), 41 deletions(-)


Update Documentation/driver-api/vfio-mediated-device.rst where mtty sample code explained. Tree command output should be updated, i.e remove below 2 lines.
|-- mtty_dev
| `-- sample_mtty_dev

Rest looks good to me.

Thanks,
Kirti