kernel/linux.git/drivers/vfio/mdev/mdev_core.c, branch v7.0-rc7

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

drivers: core: remove device_link argument from class_compat_[create|remove]_link

2025-01-10T14:42:20+00:00

After 7e722083fcc3 ("i2c: Remove I2C_COMPAT config symbol and related code") there's no caller left passing a non-null device_link argument. So remove this argument to simplify the code. Signed-off-by: Heiner Kallweit Link: https://lore.kernel.org/r/db49131d-fd79-4f23-93f2-0ab541a345fa@gmail.com Signed-off-by: Greg Kroah-Hartman

vfio/mdev: Move the compat_class initialization to module init

2023-06-27T18:05:26+00:00

The pointer to mdev_bus_compat_class is statically defined at the top of mdev_core, and was originally (commit 7b96953bc640 ("vfio: Mediated device Core driver") serialized by the parent_list_lock. The blamed commit removed this mutex, leaving the pointer initialization unserialized. As a result, the creation of multiple MDEVs in parallel (such as during boot) can encounter errors during the creation of the sysfs entries, such as: [ 8.337509] sysfs: cannot create duplicate filename '/class/mdev_bus' [ 8.337514] vfio_ccw 0.0.01d8: MDEV: Registered [ 8.337516] CPU: 13 PID: 946 Comm: driverctl Not tainted 6.4.0-rc7 #20 [ 8.337522] Hardware name: IBM 3906 M05 780 (LPAR) [ 8.337525] Call Trace: [ 8.337528] [<0000000162b0145a>] dump_stack_lvl+0x62/0x80 [ 8.337540] [<00000001622aeb30>] sysfs_warn_dup+0x78/0x88 [ 8.337549] [<00000001622aeca6>] sysfs_create_dir_ns+0xe6/0xf8 [ 8.337552] [<0000000162b04504>] kobject_add_internal+0xf4/0x340 [ 8.337557] [<0000000162b04d48>] kobject_add+0x78/0xd0 [ 8.337561] [<0000000162b04e0a>] kobject_create_and_add+0x6a/0xb8 [ 8.337565] [<00000001627a110e>] class_compat_register+0x5e/0x90 [ 8.337572] [<000003ff7fd815da>] mdev_register_parent+0x102/0x130 [mdev] [ 8.337581] [<000003ff7fdc7f2c>] vfio_ccw_sch_probe+0xe4/0x178 [vfio_ccw] [ 8.337588] [<0000000162a7833c>] css_probe+0x44/0x80 [ 8.337599] [<000000016279f4da>] really_probe+0xd2/0x460 [ 8.337603] [<000000016279fa08>] driver_probe_device+0x40/0xf0 [ 8.337606] [<000000016279fb78>] __device_attach_driver+0xc0/0x140 [ 8.337610] [<000000016279cbe0>] bus_for_each_drv+0x90/0xd8 [ 8.337618] [<00000001627a00b0>] __device_attach+0x110/0x190 [ 8.337621] [<000000016279c7c8>] bus_rescan_devices_helper+0x60/0xb0 [ 8.337626] [<000000016279cd48>] drivers_probe_store+0x48/0x80 [ 8.337632] [<00000001622ac9b0>] kernfs_fop_write_iter+0x138/0x1f0 [ 8.337635] [<00000001621e5e14>] vfs_write+0x1ac/0x2f8 [ 8.337645] [<00000001621e61d8>] ksys_write+0x70/0x100 [ 8.337650] [<0000000162b2bdc4>] __do_syscall+0x1d4/0x200 [ 8.337656] [<0000000162b3c828>] system_call+0x70/0x98 [ 8.337664] kobject: kobject_add_internal failed for mdev_bus with -EEXIST, don't try to register things with the same name in the same directory. [ 8.337668] kobject: kobject_create_and_add: kobject_add error: -17 [ 8.337674] vfio_ccw: probe of 0.0.01d9 failed with error -12 [ 8.342941] vfio_ccw_mdev aeb9ca91-10c6-42bc-a168-320023570aea: Adding to iommu group 2 Move the initialization of the mdev_bus_compat_class pointer to the init path, to match the cleanup in module exit. This way the code in mdev_register_parent() can simply link the new parent to it, rather than determining whether initialization is required first. Fixes: 89345d5177aa ("vfio/mdev: embedd struct mdev_parent in the parent data structure") Reported-by: Alexander Egorenkov Signed-off-by: Eric Farman Reviewed-by: Kevin Tian Reviewed-by: Christoph Hellwig Reviewed-by: Tony Krowiak Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20230626133642.2939168-1-farman@linux.ibm.com Signed-off-by: Alex Williamson

vfio/mdev: add mdev available instance checking to the core

2022-10-04T18:06:58+00:00

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_parent. Implement it using correct locking, fixing mdpy. Drivers just provide the value in the mdev_driver at registration time and the core code takes care of maintaining it and exposing the value in sysfs. [hch: count instances per-parent instead of per-type, use an atomic_t to avoid taking mdev_list_lock in the show method] Signed-off-by: Jason Gunthorpe Signed-off-by: Christoph Hellwig Reviewed-by: Kevin Tian Reviewed-by: Kirti Wankhede Reviewed-by: Eric Farman Link: https://lore.kernel.org/r/20220923092652.100656-15-hch@lst.de Signed-off-by: Alex Williamson

vfio/mdev: remove mtype_get_parent_dev

2022-10-04T18:06:58+00:00

Just open code the dereferences in the only user. Signed-off-by: Christoph Hellwig Reviewed-by: Jason Gunthorpe Reviewed-by: Jason J. Herne Reviewed-by: Kevin Tian Reviewed-by: Kirti Wankhede Reviewed-by: Eric Farman Link: https://lore.kernel.org/r/20220923092652.100656-10-hch@lst.de Signed-off-by: Alex Williamson

vfio/mdev: remove mdev_parent_dev

2022-10-04T18:06:58+00:00

Just open code the dereferences in the only user. Signed-off-by: Christoph Hellwig Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Reviewed-by: Kirti Wankhede Link: https://lore.kernel.org/r/20220923092652.100656-9-hch@lst.de Signed-off-by: Alex Williamson

vfio/mdev: remove mdev_from_dev

2022-10-04T18:06:58+00:00

Just open code it in the only caller. Signed-off-by: Christoph Hellwig Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Reviewed-by: Kirti Wankhede Link: https://lore.kernel.org/r/20220923092652.100656-7-hch@lst.de Signed-off-by: Alex Williamson

vfio/mdev: simplify mdev_type handling

2022-10-04T18:06:58+00:00

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 Reviewed-by: Jason Gunthorpe Reviewed-by: Tony Krowiak Reviewed-by: Kevin Tian Reviewed-by: Kirti Wankhede Reviewed-by: Eric Farman Link: https://lore.kernel.org/r/20220923092652.100656-6-hch@lst.de Signed-off-by: Alex Williamson

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

2022-10-04T18:06:58+00:00

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 Reviewed-by: Jason Gunthorpe Reviewed-by: Tony Krowiak Reviewed-by: Kevin Tian Reviewed-by: Kirti Wankhede Reviewed-by: Eric Farman Link: https://lore.kernel.org/r/20220923092652.100656-5-hch@lst.de Signed-off-by: Alex Williamson