Re: [PATCH v1 14/18] vfio/mdev: Add mdev available instance checking to the core

Matthew Rosato
2022-06-06T20:46:30Z

On 6/6/22 4:23 PM, Eric Farman wrote:
> On Tue, 2022-06-07 at 01:32 +0530, Kirti Wankhede wrote:
>>
>> On 6/2/2022 10:49 PM, Eric Farman wrote:
>>> From: Jason Gunthorpe <jgg@nvidia.com>
>>>
>>> Many of the mdev drivers use a simple counter for keeping track of
>>> the
>>> available instances. Move this code to the core code and store the
>>> counter
>>> in the mdev_type. Implement it using correct locking, fixing mdpy.
>>>
>>> Drivers provide a get_available() callback to set the number of
>>> available
>>> instances for their mtypes which is fixed at registration time. The
>>> core
>>> provides a standard sysfs attribute to return the
>>> available_instances.
>>>
>>> Cc: Kirti Wankhede <kwankhede@nvidia.com>
>>> Cc: Jonathan Corbet <corbet@lwn.net>
>>> Cc: Tony Krowiak <akrowiak@linux.ibm.com>
>>> Cc: Jason Herne <jjherne@linux.ibm.com>
>>> Reviewed-by: Christoph Hellwig <hch@lst.de>
>>> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
>>> Link:
>>> https://lore.kernel.org/r/7-v3-57c1502c62fd+2190-ccw_mdev_jgg@nvidia.com/
>>> [farman: added Cc: tags]
>>> Signed-off-by: Eric Farman <farman@linux.ibm.com>
>>> ---
>>> .../driver-api/vfio-mediated-device.rst | 4 +-
>>> drivers/s390/cio/vfio_ccw_drv.c | 1 -
>>> drivers/s390/cio/vfio_ccw_ops.c | 26 ++++---------
>>> drivers/s390/cio/vfio_ccw_private.h | 2 -
>>> drivers/s390/crypto/vfio_ap_ops.c | 32 ++++--------
>>> ----
>>> drivers/s390/crypto/vfio_ap_private.h | 2 -
>>> drivers/vfio/mdev/mdev_core.c | 11 +++++-
>>> drivers/vfio/mdev/mdev_private.h | 2 +
>>> drivers/vfio/mdev/mdev_sysfs.c | 37
>>> +++++++++++++++++++
>>> include/linux/mdev.h | 2 +
>>> samples/vfio-mdev/mdpy.c | 22 +++--------
>>> 11 files changed, 76 insertions(+), 65 deletions(-)
>>>
>>> diff --git a/Documentation/driver-api/vfio-mediated-device.rst
>>> b/Documentation/driver-api/vfio-mediated-device.rst
>>> index f410a1cd98bb..a4f7f1362fa8 100644
>>> --- a/Documentation/driver-api/vfio-mediated-device.rst
>>> +++ b/Documentation/driver-api/vfio-mediated-device.rst
>>> @@ -106,6 +106,7 @@ structure to represent a mediated device's
>>> driver::
>>> int (*probe) (struct mdev_device *dev);
>>> void (*remove) (struct mdev_device *dev);
>>> struct device_driver driver;
>>> + unsigned int (*get_available)(struct mdev_type *mtype);
>>> };
>>>
>>
>> This patch conflicts with Christoph Hellwig's patch. I see
>> 'supported_type_groups' is not is above structure, I beleive that
>> your
>> patch is applied on top of Christoph's patch series.
>>
>> but then in below part of code, 'add_mdev_supported_type' has also
>> being
>> removed in Christoph's patch. So this patch would not get applied
>> cleanly.
>
> Apologies. This series was fit to 5.18 as the merge window progressed.
> Both this patch and the previous one have to adjust to the removal of
> mdev_parent_ops that came about from
>
> commit 6b42f491e17ce13f5ff7f2d1f49c73a0f4c47b20
> Author: Jason Gunthorpe <jgg@ziepe.ca>
> Date: Mon Apr 11 16:14:01 2022 +0200
>
> vfio/mdev: Remove mdev_parent_ops
>
> I have this rebased for v2.
>
> Eric

Thanks Eric -- FYI, I'm planning to review the entire series but will
likely hold off until v2 on a number of patches at this point as there
are a few other collisions with 5.19