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Kevin Tian cb9ff3f3b8 vfio: Add helpers for unifying vfio_device life cycle
The idea is to let vfio core manage the vfio_device life cycle instead
of duplicating the logic cross drivers. This is also a preparatory
step for adding struct device into vfio_device.

New pair of helpers together with a kref in vfio_device:

 - vfio_alloc_device()
 - vfio_put_device()

Drivers can register @init/@release callbacks to manage any private
state wrapping the vfio_device.

However vfio-ccw doesn't fit this model due to a life cycle mess
that its private structure mixes both parent and mdev info hence must
be allocated/freed outside of the life cycle of vfio device.

Per prior discussions this won't be fixed in short term by IBM folks.

Instead of waiting for those modifications introduce another helper
vfio_init_device() so ccw can call it to initialize a pre-allocated
vfio_device.

Further implication of the ccw trick is that vfio_device cannot be
freed uniformly in vfio core. Instead, require *EVERY* driver to
implement @release and free vfio_device inside. Then ccw can choose
to delay the free at its own discretion.

Another trick down the road is that kvzalloc() is used to accommodate
the need of gvt which uses vzalloc() while all others use kzalloc().
So drivers should call a helper vfio_free_device() to free the
vfio_device instead of assuming that kfree() or vfree() is appliable.

Later once the ccw mess is fixed we can remove those tricks and
fully handle structure alloc/free in vfio core.

Existing vfio_{un}init_group_dev() will be deprecated after all
existing usages are converted to the new model.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Co-developed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20220921104401.38898-2-kevin.tian@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-21 14:15:10 -06:00
arch powerpc fixes for 6.0 #4 2022-09-04 11:33:22 -07:00
block block-6.0-2022-08-26 2022-08-26 11:05:54 -07:00
certs Kbuild updates for v5.20 2022-08-10 10:40:41 -07:00
crypto crypto: blake2b: effectively disable frame size warning 2022-08-10 17:59:11 -07:00
Documentation Input updates for v6.0-rc3 2022-09-03 13:09:46 -07:00
drivers vfio: Add helpers for unifying vfio_device life cycle 2022-09-21 14:15:10 -06:00
fs 5 cifs/smb3 fixes, all also for stable 2022-09-02 16:20:24 -07:00
include vfio: Add helpers for unifying vfio_device life cycle 2022-09-21 14:15:10 -06:00
init arm64 fixes for -rc3 2022-08-26 11:32:53 -07:00
io_uring io_uring-6.0-2022-09-02 2022-09-02 16:37:01 -07:00
ipc Updates to various subsystems which I help look after. lib, ocfs2, 2022-08-07 10:03:24 -07:00
kernel Networking fixes for 6.0-rc4, including fixes from bluetooth, bpf 2022-09-01 09:20:42 -07:00
lib This push fixes a boot performance regression due to an unnecessary 2022-08-31 09:47:06 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm: pagewalk: Fix race between unmap and page walker 2022-09-03 10:13:13 -07:00
net net/smc: Remove redundant refcount increase 2022-09-01 10:04:45 +02:00
samples Tracing updates for 5.20 / 6.0 2022-08-05 09:41:12 -07:00
scripts Makefile.extrawarn: re-enable -Wformat for clang; take 2 2022-09-04 11:15:50 -07:00
security Landlock fix for v6.0-rc4 2022-09-02 15:24:08 -07:00
sound ALSA: usb-audio: Add quirk for LH Labs Geek Out HD Audio 1V5 2022-08-28 09:42:14 +02:00
tools s390: 2022-09-04 11:27:14 -07:00
usr Not a lot of material this cycle. Many singleton patches against various 2022-05-27 11:22:03 -07:00
virt KVM: Drop unnecessary initialization of "ops" in kvm_ioctl_create_device() 2022-08-19 04:05:43 -04:00
.clang-format PCI/DOE: Add DOE mailbox support functions 2022-07-19 15:38:04 -07:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: split the second line of *.mod into *.usyms 2022-05-08 03:16:59 +09:00
.mailmap .mailmap: update Luca Ceresoli's e-mail address 2022-08-28 14:02:46 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS drm for 5.20/6.0 2022-08-03 19:52:08 -07:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS gpio fixes for v6.0-rc4 2022-09-03 21:27:27 -07:00
Makefile Linux 6.0-rc4 2022-09-04 13:10:01 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.