eventfd: simplify eventfd_signal()

Ever since the eventfd type was introduced back in 2007 in commit
e1ad7468c77d ("signal/timer/event: eventfd core") the eventfd_signal()
function only ever passed 1 as a value for @n. There's no point in
keeping that additional argument.

Link: https://lore.kernel.org/r/20231122-vfs-eventfd-signal-v2-2-bd549b14ce0c@kernel.org
Acked-by: Xu Yilun <yilun.xu@intel.com>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com> # ocxl
Acked-by: Eric Farman <farman@linux.ibm.com> # s390
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>

vfio/mtty: Enable migration support

The mtty driver exposes a PCI serial device to userspace and therefore
makes an easy target for a sample device supporting migration. The device
does not make use of DMA, therefore we can easily claim support for the
migration P2P states, as well as dirty logging. This implementation also
makes use of PRE_COPY support in order to provide migration stream
compatibility testing, which should generally be considered good practice.

Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/r/20231016224736.2575718-3-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/mtty: Overhaul mtty interrupt handling

The mtty driver does not currently conform to the vfio SET_IRQS uAPI.
For example, it claims to support mask and unmask of INTx, but actually
does nothing. It claims to support AUTOMASK for INTx, but doesn't. It
fails to teardown eventfds under the full semantics specified by the
SET_IRQS ioctl. It also fails to teardown eventfds when the device is
closed, leading to memory leaks. It claims to support the request IRQ,
but doesn't.

Fix all these.

A side effect of this is that QEMU will now report a warning:

vfio <uuid>: Failed to set up UNMASK eventfd signaling for interrupt \
INTX-0: VFIO_DEVICE_SET_IRQS failure: Inappropriate ioctl for device

The fact is that the unmask eventfd was never supported but quietly
failed. mtty never honored the AUTOMASK behavior, therefore there
was nothing to unmask. QEMU is verbose about the failure, but
properly falls back to userspace unmasking.

Fixes: 9d1a546c53b4 ("docs: Sample driver to demonstrate how to use Mediated device framework.")
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/r/20231016224736.2575718-2-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio-iommufd: Add detach_ioas support for emulated VFIO devices

This prepares for adding DETACH ioctl for emulated VFIO devices.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-16-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/mdev: Uses the vfio emulated iommufd ops set in the mdev sample drivers

This harmonizes the no-DMA devices (the vfio-mdev sample drivers) with
the emulated devices (gvt-g, vfio-ap etc.). It makes it easier to add
BIND_IOMMUFD user interface which requires to return an iommufd ID to
represent the device/iommufd bond.

Link: https://lore.kernel.org/r/20230327093351.44505-6-yi.l.liu@intel.com
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

driver core: class: remove module * from class_create()

The module pointer in class_create() never actually did anything, and it
shouldn't have been requred to be set as a parameter even if it did
something. So just remove it and fix up all callers of the function in
the kernel tree at the same time.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20230313181843.1207845-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vfio/ap/ccw/samples: Fix device_register() unwind path

We always need to call put_device() if device_register() fails.
All vfio drivers calling device_register() include a similar unwind
stack via gotos, therefore split device_unregister() into its
device_del() and put_device() components in the unwind path, and
add a goto target to handle only the put_device() requirement.

Reported-by: Ruan Jinjie <ruanjinjie@huawei.com>
Link: https://lore.kernel.org/all/20221118032827.3725190-1-ruanjinjie@huawei.com
Fixes: d61fc96f47fd ("sample: vfio mdev display - host device")
Fixes: 9d1a546c53b4 ("docs: Sample driver to demonstrate how to use Mediated device framework.")
Fixes: a5e6e6505f38 ("sample: vfio bochs vbe display (host device for bochs-drm)")
Fixes: 9e6f07cd1eaa ("vfio/ccw: create a parent struct")
Fixes: 36360658eb5a ("s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem")
Cc: Tony Krowiak <akrowiak@linux.ibm.com>
Cc: Halil Pasic <pasic@linux.ibm.com>
Cc: Jason Herne <jjherne@linux.ibm.com>
Cc: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Link: https://lore.kernel.org/r/166999942139.645727.12439756512449846442.stgit@omen
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Remove vfio_free_device

With the "mess" sorted out, we should be able to inline the
vfio_free_device call introduced by commit cb9ff3f3b84c
("vfio: Add helpers for unifying vfio_device life cycle")
and remove them from driver release callbacks.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com> # vfio-ap part
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221104142007.1314999-8-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/mdev: consolidate all the available_instance sysfs into the core code

Every driver just print a number, simply add a method to the mdev_driver
to return it and provide a standard sysfs show function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-13-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/mdev: consolidate all the name sysfs into the core code

Every driver just emits a static string, simply add a field to the
mdev_type for the driver to fill out or fall back to the sysfs name and
provide a standard sysfs show function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-12-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/mdev: consolidate all the device_api sysfs into the core code

Every driver just emits a static string, simply feed it through the ops
and provide a standard sysfs show function.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-11-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/mdev: simplify mdev_type handling

Instead of abusing struct attribute_group to control initialization of
struct mdev_type, just define the actual attributes in the mdev_driver,
allocate the mdev_type structures in the caller and pass them to
mdev_register_parent.

This allows the caller to use container_of to get at the containing
structure and thus significantly simplify the code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-6-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/mdev: embedd struct mdev_parent in the parent data structure

Simplify mdev_{un}register_device by requiring the caller to pass in
a structure allocate as part of the parent device structure. This
removes the need for a list of parents and the separate mdev_parent
refcount as we can simplify rely on the reference to the parent device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Link: https://lore.kernel.org/r/20220923092652.100656-5-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/mdev: make mdev.h standalone includable

Include <linux/device.h> and <linux/uuid.h> so that users of this headers
don't need to do that and remove those includes that aren't needed
any more.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20220923092652.100656-4-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/mtty: Use the new device life cycle helpers

and manage available ports inside @init/@release.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20220921104401.38898-7-kevin.tian@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/mdev: Remove mdev_parent_ops

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 <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-33-hch@lst.de
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>

vfio/mdev: Remove mdev_parent_ops dev_attr_groups

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@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-32-hch@lst.de
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>

vfio: simplify iommu group allocation for mediated devices

Reuse the logic in vfio_noiommu_group_alloc to allocate a fake
single-device iommu group for mediated devices by factoring out a common
function, and replacing the noiommu boolean field in struct vfio_group
with an enum to distinguish the three different kinds of groups.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20210924155705.4258-8-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/samples: Delete useless open/close

The core code no longer requires these ops to be defined, so delete these
empty functions and leave the op as NULL. mtty's functions only log a
pointless message, delete that entirely.

Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/5-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Introduce a vfio_uninit_group_dev() API call

This pairs with vfio_init_group_dev() and allows undoing any state that is
stored in the vfio_device unrelated to registration. Add appropriately
placed calls to all the drivers.

The following patch will use this to add pre-registration state for the
device set.

Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/3-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/mtty: Enforce available_instances

The sample mtty mdev driver doesn't actually enforce the number of
device instances it claims are available. Implement this properly.

Link: https://lore.kernel.org/r/162465624894.3338367.12935940647049917981.stgit@omen
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/mtty: Delete mdev_devices_list

Dan points out that an error case left things on this list. It is also
missing locking in available_instances_show().

Further study shows the list isn't needed at all, just store the total
ports in use in an atomic and delete the whole thing.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 09177ac91921 ("vfio/mtty: Convert to use vfio_register_group_dev()")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/0-v1-0bc56b362ca7+62-mtty_used_ports_jgg@nvidia.com
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/mtty: Convert to use vfio_register_group_dev()

This is straightforward conversion, the mdev_state is actually serving as
the vfio_device and we can replace all the mdev_get_drvdata()'s and the
wonky dead code with a simple container_of()

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20210617142218.1877096-9-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/mdev: Correct the function signatures for the mdev_type_attributes

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 <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <18-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/mdev: Remove kobj from mdev_parent_ops->create()

The kobj here is a type-erased version of mdev_type, which is already
stored in the struct mdev_device being passed in. It was only ever used to
compute the type_group_id, which is now extracted directly from the mdev.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <17-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio/mtty: Use mdev_get_type_group_id()

The type_group_id directly gives the single or dual port index, no
need for string searching.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <12-v2-d36939638fc6+d54-vfio2_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio-mdev/mtty: Simplify interrupt generation

While generating interrupt, mdev_state is already available for which
interrupt is generated.
Instead of doing indirect way from state->device->uuid-> to searching
state linearly in linked list on every interrupt generation,
directly use the available state.

Hence, simplify the code to use mdev_state and remove unused helper
function with that.

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio-mdev/samples: make some symbols static

Make some structs and functions static to fix build warning, parts of
warning shown below,

samples/vfio-mdev/mtty.c:730:5: warning: symbol 'mtty_create' was not declared. Should it be static?
samples/vfio-mdev/mtty.c:780:5: warning: symbol 'mtty_remove' was not declared. Should it be static?
samples/vfio-mdev/mtty.c:802:5: warning: symbol 'mtty_reset' was not declared. Should it be static?
samples/vfio-mdev/mtty.c:818:9: warning: symbol 'mtty_read' was not declared. Should it be static?
samples/vfio-mdev/mtty.c:877:9: warning: symbol 'mtty_write' was not declared. Should it be static?
samples/vfio-mdev/mtty.c:1070:5: warning: symbol 'mtty_get_region_info' was not declared. Should it be static?
samples/vfio-mdev/mtty.c:1119:5: warning: symbol 'mtty_get_irq_info' was not declared. Should it be static?
samples/vfio-mdev/mtty.c:1143:5: warning: symbol 'mtty_get_device_info' was not declared. Should it be static?
samples/vfio-mdev/mtty.c:1275:5: warning: symbol 'mtty_open' was not declared. Should it be static?
samples/vfio-mdev/mtty.c:1281:6: warning: symbol 'mtty_close' was not declared. Should it be static?
samples/vfio-mdev/mtty.c:1305:30: warning: symbol 'mtty_dev_groups' was not declared. Should it be static?

Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Kirti Wankhede <kwankhede@nvidia.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[aw: wrap long lines]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

samples/vfio-mdev/mtty: expand minor range when registering chrdev region

Actually, total amount of available minor number
for a single major is MINORMARK + 1. So expand
minor range when registering chrdev region.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio-mdev: Switch to use new generic UUID API

There are new types and helpers that are supposed to be used in new code.

As a preparation to get rid of legacy types and API functions do
the conversion here.

Cc: Kirti Wankhede <kwankhede@nvidia.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio-mdev/samples: Use u8 instead of char for handle functions

Clang warns:

samples/vfio-mdev/mtty.c:592:39: warning: implicit conversion from 'int'
to 'char' changes value from 162 to -94 [-Wconstant-conversion]
*buf = UART_MSR_DSR | UART_MSR_DDSR | UART_MSR_DCD;
~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~
1 warning generated.

Turns out that all uses of buf in this function ultimately end up stored
or cast to an unsigned type. Just use u8, which has the same number of
bits but can store this larger number so Clang no longer warns.

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio-mdev/samples: change RDI interrupt condition

When FIFO mode is enabled, the receive data available interrupt
(UART_IIR_RDI in code) should be triggered when the number of data
in FIFO is equal or larger than interrupt trigger level.

This patch changes the trigger level check to ensure multiple bytes
received from upper layer can trigger RDI interrupt correctly.

Cc: Joey Zheng <yu.zheng@hxt-semitech.com>
Signed-off-by: Shunyong Yang <shunyong.yang@hxt-semitech.com>
Reviewed by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio-mdev/samples: make mdev_fops const and static

Make this const as it is only passed to a const argument of the function
mdev_register_device. Make it static as it is not referenced in any
other file.

Structure found using Coccinelle and changes done by hand.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio-mdev: remove some dead code

We set info.count to 1 in mtty_get_irq_info() so static checkers
complain that, "Why do we have impossible conditions?" The answer is
that it seems to be left over dead code that can be safely removed.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio-mdev: buffer overflow in ioctl()

This is a sample driver for documentation so the impact is probably
pretty low. But we should check that bar_index is valid so we
don't write beyond the end of the mdev_state->region_info[] array.

Fixes: 9d1a546c53b4 ("docs: Sample driver to demonstrate how to use Mediated device framework.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio-mdev: return -EFAULT if copy_to_user() fails

The copy_to_user() function returns the number of bytes which it wasn't
able to copy but we want to return a negative error code.

Fixes: 9d1a546c53b4 ("docs: Sample driver to demonstrate how to use Mediated device framework.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio-mdev: fix some error codes in the sample code

This is just sample code. We forget to set the error codes in a couple
places.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reported-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio-mdev: Make mdev_device private and abstract interfaces

Abstract access to mdev_device so that we can define which interfaces
are public rather than relying on comments in the structure.

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Jike Song <jike.song@intel.com>
Reviewed by: Kirti Wankhede <kwankhede@nvidia.com>

vfio-mdev: Make mdev_parent private

Rather than hoping for good behavior by marking some elements
internal, enforce it by making the entire structure private and
creating an accessor function for the one useful external field.

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: Jike Song <jike.song@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed by: Kirti Wankhede <kwankhede@nvidia.com>

vfio-mdev: de-polute the namespace, rename parent_device & parent_ops

Add an mdev_ prefix so we're not poluting the namespace so much.

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Cc: Jike Song <jike.song@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed by: Kirti Wankhede <kwankhede@nvidia.com>

docs: Sample driver to demonstrate how to use Mediated device framework.

The Sample driver creates mdev device that simulates serial port over PCI
card.

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Neo Jia <cjia@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>