linux-toradex.git/include/linux/mdev.h, branch v6.0-rc7

vfio/ccw: Remove UUID from s390 debug log

2022-07-07T20:06:12+00:00

As vfio-ccw devices are created/destroyed, the uuid of the associated
mdevs that are recorded in $S390DBF/vfio_ccw_msg/sprintf get lost.
This is because a pointer to the UUID is stored instead of the UUID
itself, and that memory may have been repurposed if/when the logs are
examined. The result is usually garbage UUID data in the logs, though
there is an outside chance of an oops happening here.

Simply remove the UUID from the traces, as the subchannel number will
provide useful configuration information for problem determination,
and is stored directly into the log instead of a pointer.

As we were the only consumer of mdev_uuid(), remove that too.

Cc: Kirti Wankhede 
Signed-off-by: Michael Kawano 
Fixes: 60e05d1cf0875 ("vfio-ccw: add some logging")
Fixes: b7701dfbf9832 ("vfio-ccw: Register a chp_event callback for vfio-ccw")
[farman: reworded commit message, added Fixes: tags]
Signed-off-by: Eric Farman 
Reviewed-by: Jason Gunthorpe 
Reviewed-by: Matthew Rosato 
Reviewed-by: Kirti Wankhede 
Link: https://lore.kernel.org/r/20220707135737.720765-2-farman@linux.ibm.com
Signed-off-by: Alex Williamson

vfio/mdev: Remove mdev drvdata

2022-04-21T11:36:56+00:00

This is no longer used, remove it.

All usages were moved over to either use container_of() from a vfio_device
or to use dev_drvdata() directly on the mdev.

Signed-off-by: Jason Gunthorpe 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Zhi Wang 
Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-35-hch@lst.de
Reviewed-by: Kirti Wankhede 
Reviewed-by: Zhi Wang

vfio/mdev: Remove mdev_parent_ops

2022-04-21T11:36:56+00:00

The last useful member in this struct is the supported_type_groups, move
it to the mdev_driver and delete mdev_parent_ops.

Replace it with mdev_driver as an argument to mdev_register_device()

Signed-off-by: Jason Gunthorpe 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Zhi Wang 
Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-33-hch@lst.de
Reviewed-by: Kirti Wankhede 
Reviewed-by: Zhi Wang

vfio/mdev: Remove mdev_parent_ops dev_attr_groups

2022-04-21T11:36:56+00:00

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 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Zhi Wang 
Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-32-hch@lst.de
Reviewed-by: Kirti Wankhede 
Reviewed-by: Zhi Wang

vfio/mdev: Remove vfio_mdev.c

2022-04-21T11:36:56+00:00

Now that all mdev drivers directly create their own mdev_device driver and
directly register with the vfio core's vfio_device_ops this is all dead
code.

Delete vfio_mdev.c and the mdev_parent_ops members that are connected to
it.

Signed-off-by: Jason Gunthorpe 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Zhi Wang 
Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-31-hch@lst.de
Reviewed-by: Kirti Wankhede 
Reviewed-by: Zhi Wang

vfio: remove the unused mdev iommu hook

2021-09-30T18:46:44+00:00

The iommu_device field in struct mdev_device has never been used
since it was added more than 2 years ago.

This is a manual revert of commit 7bd50f0cd2
("vfio/type1: Add domain at(de)taching group helpers").

Signed-off-by: Christoph Hellwig 
Reviewed-by: Jason Gunthorpe 
Reviewed-by: Kevin Tian 
Link: https://lore.kernel.org/r/20210924155705.4258-11-hch@lst.de
Signed-off-by: Alex Williamson

vfio: Remove struct vfio_device_ops open/release

2021-08-11T15:50:11+00:00

Nothing uses this anymore, delete it.

Signed-off-by: Yishai Hadas 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jason Gunthorpe 
Reviewed-by: Cornelia Huck 
Link: https://lore.kernel.org/r/14-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.com
Signed-off-by: Alex Williamson

vfio: Provide better generic support for open/release vfio_device_ops

2021-08-11T15:50:10+00:00

Currently the driver ops have an open/release pair that is called once
each time a device FD is opened or closed. Add an additional set of
open/close_device() ops which are called when the device FD is opened for
the first time and closed for the last time.

An analysis shows that all of the drivers require this semantic. Some are
open coding it as part of their reflck implementation, and some are just
buggy and miss it completely.

To retain the current semantics PCI and FSL depend on, introduce the idea
of a "device set" which is a grouping of vfio_device's that share the same
lock around opening.

The device set is established by providing a 'set_id' pointer. All
vfio_device's that provide the same pointer will be joined to the same
singleton memory and lock across the whole set. This effectively replaces
the oddly named reflck.

After conversion the set_id will be sourced from:
 - A struct device from a fsl_mc_device (fsl)
 - A struct pci_slot (pci)
 - A struct pci_bus (pci)
 - The struct vfio_device (everything)

The design ensures that the above pointers are live as long as the
vfio_device is registered, so they form reliable unique keys to group
vfio_devices into sets.

This implementation uses xarray instead of searching through the driver
core structures, which simplifies the somewhat tricky locking in this
area.

Following patches convert all the drivers.

Signed-off-by: Yishai Hadas 
Reviewed-by: Cornelia Huck 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jason Gunthorpe 
Link: https://lore.kernel.org/r/4-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.com
Signed-off-by: Alex Williamson

vfio/mdev: Allow the mdev_parent_ops to specify the device driver to bind

2021-06-21T21:29:25+00:00

This allows a mdev driver to opt out of using vfio_mdev.c, instead the
driver will provide a 'struct mdev_driver' and register directly with the
driver core.

Much of mdev_parent_ops becomes unused in this mode:
- create()/remove() are done via the mdev_driver probe()/remove()
- mdev_attr_groups becomes mdev_driver driver.dev_groups
- Wrapper function callbacks are replaced with the same ones from
  struct vfio_device_ops

Signed-off-by: Jason Gunthorpe 
Signed-off-by: Christoph Hellwig 
Reviewed-by: Cornelia Huck 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Kirti Wankhede 
Link: https://lore.kernel.org/r/20210617142218.1877096-8-hch@lst.de
Signed-off-by: Alex Williamson

vfio/mdev: Correct the function signatures for the mdev_type_attributes

2021-04-12T16:36:00+00:00

The driver core standard is to pass in the properly typed object, the
properly typed attribute and the buffer data. It stems from the root
kobject method:

  ssize_t (*show)(struct kobject *kobj, struct kobj_attribute *attr,..)

Each subclass of kobject should provide their own function with the same
signature but more specific types, eg struct device uses:

  ssize_t (*show)(struct device *dev, struct device_attribute *attr,..)

In this case the existing signature is:

  ssize_t (*show)(struct kobject *kobj, struct device *dev,..)

Where kobj is a 'struct mdev_type *' and dev is 'mdev_type->parent->dev'.

Change the mdev_type related sysfs attribute functions to:

  ssize_t (*show)(struct mdev_type *mtype, struct mdev_type_attribute *attr,..)

In order to restore type safety and match the driver core standard

There are no current users of 'attr', but if it is ever needed it would be
hard to add in retroactively, so do it now.

Reviewed-by: Kevin Tian 
Reviewed-by: Cornelia Huck 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jason Gunthorpe 
Message-Id: <18-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson