vfio: mdev: Remove unused function declarations

The definition of mdev_bus_register() and mdev_bus_unregister() have been
removed since commit 6c7f98b334a3 ("vfio/mdev: Remove vfio_mdev.c"). So,
let

vfio: mdev: Remove unused function declarations

The definition of mdev_bus_register() and mdev_bus_unregister() have been
removed since commit 6c7f98b334a3 ("vfio/mdev: Remove vfio_mdev.c"). So,
let's remove the unused declarations.

Signed-off-by: Zhang Zekun <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alex Williamson <[email protected]>

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vfio: mdev: make mdev_bus_type const

Now that the driver core can properly handle constant struct bus_type,
move the mdev_bus_type variable to be a constant structure as well,
placing it into read-o

vfio: mdev: make mdev_bus_type const

Now that the driver core can properly handle constant struct bus_type,
move the mdev_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.

Cc: Greg Kroah-Hartman <[email protected]>
Suggested-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Ricardo B. Marliere <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Reviewed-by: Kirti Wankhede <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alex Williamson <[email protected]>

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vfio/mdev: unexport mdev_bus_type

mdev_bus_type is only used in mdev.ko now, so unexport it.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Reviewed-by:

vfio/mdev: unexport mdev_bus_type

mdev_bus_type is only used in mdev.ko now, so unexport it.

Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Reviewed-by: Kirti Wankhede <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alex Williamson <[email protected]>

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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 mde

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 <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Reviewed-by: Tony Krowiak <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Reviewed-by: Kirti Wankhede <[email protected]>
Reviewed-by: Eric Farman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alex Williamson <[email protected]>

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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. T

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 <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Reviewed-by: Tony Krowiak <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Reviewed-by: Kirti Wankhede <[email protected]>
Reviewed-by: Eric Farman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alex Williamson <[email protected]>

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vfio/mdev: Use the driver core to create the 'remove' file

The device creator is supposed to use the dev.groups value to add sysfs
files before device_add is called, not call sysfs_create_files() af

vfio/mdev: Use the driver core to create the 'remove' file

The device creator is supposed to use the dev.groups value to add sysfs
files before device_add is called, not call sysfs_create_files() after
device_add() returns. This creates a race with uevent delivery where the
extra attribute will not be visible.

This was being done because the groups had been co-opted by the mdev
driver, now that prior patches have moved the driver's groups to the
struct device_driver the dev.group is properly free for use here.

Signed-off-by: Jason Gunthorpe <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Zhi Wang <[email protected]>
Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]
Reviewed-by: Kirti Wankhede <[email protected]>
Reviewed-by: Zhi Wang <[email protected]>

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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 argume

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 <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Zhi Wang <[email protected]>
Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]
Reviewed-by: Kirti Wankhede <[email protected]>
Reviewed-by: Zhi Wang <[email protected]>

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vfio/mdev: Remove vfio_mdev.c

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_md

vfio/mdev: Remove vfio_mdev.c

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 <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Zhi Wang <[email protected]>
Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]
Reviewed-by: Kirti Wankhede <[email protected]>
Reviewed-by: Zhi Wang <[email protected]>

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vfio/mdev: Remove CONFIG_VFIO_MDEV_DEVICE

For some reason the vfio_mdev shim mdev_driver has its own module and
kconfig. As the next patch requires access to it from mdev.ko merge the
two modules to

vfio/mdev: Remove CONFIG_VFIO_MDEV_DEVICE

For some reason the vfio_mdev shim mdev_driver has its own module and
kconfig. As the next patch requires access to it from mdev.ko merge the
two modules together and remove VFIO_MDEV_DEVICE.

A later patch deletes this driver entirely.

Signed-off-by: Jason Gunthorpe <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Reviewed-by: Kirti Wankhede <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alex Williamson <[email protected]>

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vfio/mdev: Add mdev/mtype_get_type_group_id()

This returns the index in the supported_type_groups array that is
associated with the mdev_type attached to the struct mdev_device or its
containing str

vfio/mdev: Add mdev/mtype_get_type_group_id()

This returns the index in the supported_type_groups array that is
associated with the mdev_type attached to the struct mdev_device or its
containing struct kobject.

Each mdev_device can be spawned from exactly one mdev_type, which in turn
originates from exactly one supported_type_group.

Drivers are using weird string calculations to try and get back to this
index, providing a direct access to the index removes a bunch of wonky
driver code.

mdev_type->group can be deleted as the group is obtained using the
type_group_id.

Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>

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vfio/mdev: Expose mdev_get/put_parent to mdev_private.h

The next patch will use these in mdev_sysfs.c

While here remove the now dead code checks for NULL, a mdev_type can never
have a NULL parent.

vfio/mdev: Expose mdev_get/put_parent to mdev_private.h

The next patch will use these in mdev_sysfs.c

While here remove the now dead code checks for NULL, a mdev_type can never
have a NULL parent.

Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>

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vfio/mdev: Use struct mdev_type in struct mdev_device

The kobj pointer in mdev_device is actually pointing at a struct
mdev_type. Use the proper type so things are understandable.

There are a numbe

vfio/mdev: Use struct mdev_type in struct mdev_device

The kobj pointer in mdev_device is actually pointing at a struct
mdev_type. Use the proper type so things are understandable.

There are a number of places that are confused and passing both the mdev
and the mtype as function arguments, fix these to derive the mtype
directly from the mdev to remove the redundancy.

Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>

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vfio/mdev: Add missing typesafety around mdev_device

The mdev API should accept and pass a 'struct mdev_device *' in all
places, not pass a 'struct device *' and cast it internally with
to_mdev_devi

vfio/mdev: Add missing typesafety around mdev_device

The mdev API should accept and pass a 'struct mdev_device *' in all
places, not pass a 'struct device *' and cast it internally with
to_mdev_device(). Particularly in its struct mdev_driver functions, the
whole point of a bus's struct device_driver wrapper is to provide type
safety compared to the default struct device_driver.

Further, the driver core standard is for bus drivers to expose their
device structure in their public headers that can be used with
container_of() inlines and '&foo->dev' to go between the class levels, and
'&foo->dev' to be used with dev_err/etc driver core helper functions. Move
'struct mdev_device' to mdev.h

Once done this allows moving some one instruction exported functions to
static inlines, which in turns allows removing one of the two grotesque
symbol_get()'s related to mdev in the core code.

Reviewed-by: Kevin Tian <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>

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vfio/mdev: Make to_mdev_device() into a static inline

The macro wrongly uses 'dev' as both the macro argument and the member
name, which means it fails compilation if any caller uses a word other
th

vfio/mdev: Make to_mdev_device() into a static inline

The macro wrongly uses 'dev' as both the macro argument and the member
name, which means it fails compilation if any caller uses a word other
than 'dev' as the single argument. Fix this defect by making it into
proper static inline, which is more clear and typesafe anyhow.

Fixes: 99e3123e3d72 ("vfio-mdev: Make mdev_device private and abstract interfaces")
Reviewed-by: Christoph Hellwig <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>

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vfio/mdev: Fix spelling mistake "interal" -> "internal"

There is a spelling mistake in a comment, fix it.

Signed-off-by: Zhen Lei <[email protected]>
Reviewed-by: Eric Auger <eric.auger@re

vfio/mdev: Fix spelling mistake "interal" -> "internal"

There is a spelling mistake in a comment, fix it.

Signed-off-by: Zhen Lei <[email protected]>
Reviewed-by: Eric Auger <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>

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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 th

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 <[email protected]>
Reviewed-by: Enrico Weigelt <[email protected]>
Reviewed-by: Kate Stewart <[email protected]>
Reviewed-by: Allison Randal <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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vfio/mdev: Synchronize device create/remove with parent removal

In following sequences, child devices created while removing mdev parent
device can be left out, or it may lead to race of removing ha

vfio/mdev: Synchronize device create/remove with parent removal

In following sequences, child devices created while removing mdev parent
device can be left out, or it may lead to race of removing half
initialized child mdev devices.

issue-1:
--------
cpu-0 cpu-1
----- -----
mdev_unregister_device()
device_for_each_child()
mdev_device_remove_cb()
mdev_device_remove()
create_store()
mdev_device_create() [...]
device_add()
parent_remove_sysfs_files()

/* BUG: device added by cpu-0
* whose parent is getting removed
* and it won't process this mdev.
*/

issue-2:
--------
Below crash is observed when user initiated remove is in progress
and mdev_unregister_driver() completes parent unregistration.

cpu-0 cpu-1
----- -----
remove_store()
mdev_device_remove()
active = false;
mdev_unregister_device()
parent device removed.
[...]
parents->ops->remove()
/*
* BUG: Accessing invalid parent.
*/

This is similar race like create() racing with mdev_unregister_device().

BUG: unable to handle kernel paging request at ffffffffc0585668
PGD e8f618067 P4D e8f618067 PUD e8f61a067 PMD 85adca067 PTE 0
Oops: 0000 [#1] SMP PTI
CPU: 41 PID: 37403 Comm: bash Kdump: loaded Not tainted 5.1.0-rc6-vdevbus+ #6
Hardware name: Supermicro SYS-6028U-TR4+/X10DRU-i+, BIOS 2.0b 08/09/2016
RIP: 0010:mdev_device_remove+0xfa/0x140 [mdev]
Call Trace:
remove_store+0x71/0x90 [mdev]
kernfs_fop_write+0x113/0x1a0
vfs_write+0xad/0x1b0
ksys_write+0x5a/0xe0
do_syscall_64+0x5a/0x210
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Therefore, mdev core is improved as below to overcome above issues.

Wait for any ongoing mdev create() and remove() to finish before
unregistering parent device.
This continues to allow multiple create and remove to progress in
parallel for different mdev devices as most common case.
At the same time guard parent removal while parent is being accessed by
create() and remove() callbacks.
create()/remove() and unregister_device() are synchronized by the rwsem.

Refactor device removal code to mdev_device_remove_common() to avoid
acquiring unreg_sem of the parent.

Fixes: 7b96953bc640 ("vfio: Mediated device Core driver")
Signed-off-by: Parav Pandit <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>

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vfio/mdev: Improve the create/remove sequence

This patch addresses below two issues and prepares the code to address
3rd issue listed below.

1. mdev device is placed on the mdev bus before it is cr

vfio/mdev: Improve the create/remove sequence

This patch addresses below two issues and prepares the code to address
3rd issue listed below.

1. mdev device is placed on the mdev bus before it is created in the
vendor driver. Once a device is placed on the mdev bus without creating
its supporting underlying vendor device, mdev driver's probe() gets
triggered. However there isn't a stable mdev available to work on.

create_store()
mdev_create_device()
device_register()
...
vfio_mdev_probe()
[...]
parent->ops->create()
vfio_ap_mdev_create()
mdev_set_drvdata(mdev, matrix_mdev);
/* Valid pointer set above */

Due to this way of initialization, mdev driver who wants to use the mdev,
doesn't have a valid mdev to work on.

2. Current creation sequence is,
parent->ops_create()
groups_register()

Remove sequence is,
parent->ops->remove()
groups_unregister()

However, remove sequence should be exact mirror of creation sequence.
Once this is achieved, all users of the mdev will be terminated first
before removing underlying vendor device.
(Follow standard linux driver model).
At that point vendor's remove() ops shouldn't fail because taking the
device off the bus should terminate any usage.

3. When remove operation fails, mdev sysfs removal attempts to add the
file back on already removed device. Following call trace [1] is observed.

[1] call trace:
kernel: WARNING: CPU: 2 PID: 9348 at fs/sysfs/file.c:327 sysfs_create_file_ns+0x7f/0x90
kernel: CPU: 2 PID: 9348 Comm: bash Kdump: loaded Not tainted 5.1.0-rc6-vdevbus+ #6
kernel: Hardware name: Supermicro SYS-6028U-TR4+/X10DRU-i+, BIOS 2.0b 08/09/2016
kernel: RIP: 0010:sysfs_create_file_ns+0x7f/0x90
kernel: Call Trace:
kernel: remove_store+0xdc/0x100 [mdev]
kernel: kernfs_fop_write+0x113/0x1a0
kernel: vfs_write+0xad/0x1b0
kernel: ksys_write+0x5a/0xe0
kernel: do_syscall_64+0x5a/0x210
kernel: entry_SYSCALL_64_after_hwframe+0x49/0xbe

Therefore, mdev core is improved in following ways.

1. Split the device registration/deregistration sequence so that some
things can be done between initialization of the device and hooking it
up to the bus respectively after deregistering it from the bus but
before giving up our final reference.
In particular, this means invoking the ->create() and ->remove()
callbacks in those new windows. This gives the vendor driver an
initialized mdev device to work with during creation.
At the same time, a bus driver who wish to bind to mdev driver also
gets initialized mdev device.

This follows standard Linux kernel bus and device model.

2. During remove flow, first remove the device from the bus. This
ensures that any bus specific devices are removed.
Once device is taken off the mdev bus, invoke remove() of mdev
from the vendor driver.

3. The driver core device model provides way to register and auto
unregister the device sysfs attribute groups at dev->groups.
Make use of dev->groups to let core create the groups and eliminate
code to avoid explicit groups creation and removal.

To ensure, that new sequence is solid, a below stack dump of a
process is taken who attempts to remove the device while device is in
use by vfio driver and user application.
This stack dump validates that vfio driver guards against such device
removal when device is in use.

cat /proc/21962/stack
[<0>] vfio_del_group_dev+0x216/0x3c0 [vfio]
[<0>] mdev_remove+0x21/0x40 [mdev]
[<0>] device_release_driver_internal+0xe8/0x1b0
[<0>] bus_remove_device+0xf9/0x170
[<0>] device_del+0x168/0x350
[<0>] mdev_device_remove_common+0x1d/0x50 [mdev]
[<0>] mdev_device_remove+0x8c/0xd0 [mdev]
[<0>] remove_store+0x71/0x90 [mdev]
[<0>] kernfs_fop_write+0x113/0x1a0
[<0>] vfs_write+0xad/0x1b0
[<0>] ksys_write+0x5a/0xe0
[<0>] do_syscall_64+0x5a/0x210
[<0>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[<0>] 0xffffffffffffffff

This prepares the code to eliminate calling device_create_file() in
subsequent patch.

Reviewed-by: Cornelia Huck <[email protected]>
Signed-off-by: Parav Pandit <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>

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vfio/mdev: Removed unused kref

Remove unused kref from the mdev_device structure.

Fixes: 7b96953bc640 ("vfio: Mediated device Core driver")
Reviewed-by: Cornelia Huck <[email protected]>
Reviewed-b

vfio/mdev: Removed unused kref

Remove unused kref from the mdev_device structure.

Fixes: 7b96953bc640 ("vfio: Mediated device Core driver")
Reviewed-by: Cornelia Huck <[email protected]>
Reviewed-by: Kirti Wankhede <[email protected]>
Reviewed-by: Maxim Levitsky <[email protected]>
Signed-off-by: Parav Pandit <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>

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vfio/mdev: Add iommu related member in mdev_device

A parent device might create different types of mediated
devices. For example, a mediated device could be created
by the parent device with full is

vfio/mdev: Add iommu related member in mdev_device

A parent device might create different types of mediated
devices. For example, a mediated device could be created
by the parent device with full isolation and protection
provided by the IOMMU. One usage case could be found on
Intel platforms where a mediated device is an assignable
subset of a PCI, the DMA requests on behalf of it are all
tagged with a PASID. Since IOMMU supports PASID-granular
translations (scalable mode in VT-d 3.0), this mediated
device could be individually protected and isolated by an
IOMMU.

This patch adds a new member in the struct mdev_device to
indicate that the mediated device represented by mdev could
be isolated and protected by attaching a domain to a device
represented by mdev->iommu_device. It also adds a helper to
add or set the iommu device.

* mdev_device->iommu_device
- This, if set, indicates that the mediated device could
be fully isolated and protected by IOMMU via attaching
an iommu domain to this device. If empty, it indicates
using vendor defined isolation, hence bypass IOMMU.

* mdev_set/get_iommu_device(dev, iommu_device)
- Set or get the iommu device which represents this mdev
in IOMMU's device scope. Drivers don't need to set the
iommu device if it uses vendor defined isolation.

Cc: Ashok Raj <[email protected]>
Cc: Jacob Pan <[email protected]>
Cc: Kevin Tian <[email protected]>
Cc: Liu Yi L <[email protected]>
Suggested-by: Kevin Tian <[email protected]>
Suggested-by: Alex Williamson <[email protected]>
Signed-off-by: Lu Baolu <[email protected]>
Reviewed-by: Jean-Philippe Brucker <[email protected]>
Reviewed-by: Kirti Wankhede <[email protected]>
Acked-by: Alex Williamson <[email protected]>
Signed-off-by: Joerg Roedel <[email protected]>

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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 conversi

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 <[email protected]>
Cc: Alex Williamson <[email protected]>
Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>

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vfio/mdev: Check globally for duplicate devices

When we create an mdev device, we check for duplicates against the
parent device and return -EEXIST if found, but the mdev device
namespace is global

vfio/mdev: Check globally for duplicate devices

When we create an mdev device, we check for duplicates against the
parent device and return -EEXIST if found, but the mdev device
namespace is global since we'll link all devices from the bus. We do
catch this later in sysfs_do_create_link_sd() to return -EEXIST, but
with it comes a kernel warning and stack trace for trying to create
duplicate sysfs links, which makes it an undesirable response.

Therefore we should really be looking for duplicates across all mdev
parent devices, or as implemented here, against our mdev device list.
Using mdev_list to prevent duplicates means that we can remove
mdev_parent.lock, but in order not to serialize mdev device creation
and removal globally, we add mdev_device.active which allows UUIDs to
be reserved such that we can drop the mdev_list_lock before the mdev
device is fully in place.

Two behavioral notes; first, mdev_parent.lock had the side-effect of
serializing mdev create and remove ops per parent device. This was
an implementation detail, not an intentional guarantee provided to
the mdev vendor drivers. Vendor drivers can trivially provide this
serialization internally if necessary. Second, review comments note
the new -EAGAIN behavior when the device, and in particular the remove
attribute, becomes visible in sysfs. If a remove is triggered prior
to completion of mdev_device_create() the user will see a -EAGAIN
error. While the errno is different, receiving an error during this
period is not, the previous implementation returned -ENODEV for the
same condition. Furthermore, the consistency to the user is improved
in the case where mdev_device_remove_ops() returns error. Previously
concurrent calls to mdev_device_remove() could see the device
disappear with -ENODEV and return in the case of error. Now a user
would see -EAGAIN while the device is in this transitory state.

Reviewed-by: Kirti Wankhede <[email protected]>
Reviewed-by: Cornelia Huck <[email protected]>
Acked-by: Halil Pasic <[email protected]>
Acked-by: Zhenyu Wang <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>

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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: Zh

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 <[email protected]>
Cc: Zhi Wang <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>
Reviewed-by: Jike Song <[email protected]>
Reviewed by: Kirti Wankhede <[email protected]>

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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 th

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 <[email protected]>
Cc: Zhi Wang <[email protected]>
Cc: Jike Song <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>
Reviewed by: Kirti Wankhede <[email protected]>

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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 <[email protected]>
Cc: Zhi Wang <zhi.a.

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 <[email protected]>
Cc: Zhi Wang <[email protected]>
Cc: Jike Song <[email protected]>
Signed-off-by: Alex Williamson <[email protected]>
Reviewed by: Kirti Wankhede <[email protected]>

show more ...