linux.git/samples/vfio-mdev, branch v6.18.21

module: Convert symbol namespace to string literal

2024-12-02T19:34:44+00:00

Clean up the existing export namespace code along the same lines of
commit 33def8498fdd ("treewide: Convert macro and uses of __section(foo)
to __section("foo")") and for the same reason, it is not desired for the
namespace argument to be a macro expansion itself.

Scripted using

  git grep -l -e MODULE_IMPORT_NS -e EXPORT_SYMBOL_NS | while read file;
  do
    awk -i inplace '
      /^#define EXPORT_SYMBOL_NS/ {
        gsub(/__stringify\(ns\)/, "ns");
        print;
        next;
      }
      /^#define MODULE_IMPORT_NS/ {
        gsub(/__stringify\(ns\)/, "ns");
        print;
        next;
      }
      /MODULE_IMPORT_NS/ {
        $0 = gensub(/MODULE_IMPORT_NS\(([^)]*)\)/, "MODULE_IMPORT_NS(\"\\1\")", "g");
      }
      /EXPORT_SYMBOL_NS/ {
        if ($0 ~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+),/) {
  	if ($0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/ &&
  	    $0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(\)/ &&
  	    $0 !~ /^my/) {
  	  getline line;
  	  gsub(/[[:space:]]*\\$/, "");
  	  gsub(/[[:space:]]/, "", line);
  	  $0 = $0 " " line;
  	}

  	$0 = gensub(/(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/,
  		    "\\1(\\2, \"\\3\")", "g");
        }
      }
      { print }' $file;
  done

Requested-by: Masahiro Yamada 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://mail.google.com/mail/u/2/#inbox/FMfcgzQXKWgMmjdFwwdsfgxzKpVHWPlc
Acked-by: Greg KH 
Signed-off-by: Linus Torvalds

[tree-wide] finally take no_llseek out

2024-09-27T15:18:43+00:00

no_llseek had been defined to NULL two years ago, in commit 868941b14441
("fs: remove no_llseek")

To quote that commit,

  At -rc1 we'll need do a mechanical removal of no_llseek -

  git grep -l -w no_llseek | grep -v porting.rst | while read i; do
	sed -i '/\/d' $i
  done

  would do it.

Unfortunately, that hadn't been done.  Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
	.llseek = no_llseek,
so it's obviously safe.

Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds

vfio-mdev: add missing MODULE_DESCRIPTION() macros

2024-07-17T18:24:13+00:00

Since commit 1fffe7a34c89 ("script: modpost: emit a warning when the
description is missing"), a module without a MODULE_DESCRIPTION() will
result in a warning with make W=1. The following warnings are being
observed in samples/vfio-mdev:

WARNING: modpost: missing MODULE_DESCRIPTION() in samples/vfio-mdev/mtty.o
WARNING: modpost: missing MODULE_DESCRIPTION() in samples/vfio-mdev/mdpy.o
WARNING: modpost: missing MODULE_DESCRIPTION() in samples/vfio-mdev/mdpy-fb.o
WARNING: modpost: missing MODULE_DESCRIPTION() in samples/vfio-mdev/mbochs.o

Add the missing invocations of the MODULE_DESCRIPTION() macro to these
modules. And in the case of mtty.c, remove the now redundant instance
of the MODULE_INFO() macro.

Signed-off-by: Jeff Johnson 
Link: https://lore.kernel.org/r/20240715-md-vfio-mdev-v2-1-59a4c5e924bc@quicinc.com
Signed-off-by: Alex Williamson

vfio/mbochs: make mbochs_class constant

2024-03-05T22:15:27+00:00

Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the mbochs_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: Greg Kroah-Hartman 
Suggested-by: Greg Kroah-Hartman 
Signed-off-by: Ricardo B. Marliere 
Link: https://lore.kernel.org/r/20240301-class_cleanup-vfio-v1-2-9236d69083f5@marliere.net
Signed-off-by: Alex Williamson

vfio/mdpy: make mdpy_class constant

2024-03-05T22:15:27+00:00

Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the mdpy_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: Greg Kroah-Hartman 
Suggested-by: Greg Kroah-Hartman 
Signed-off-by: Ricardo B. Marliere 
Link: https://lore.kernel.org/r/20240301-class_cleanup-vfio-v1-1-9236d69083f5@marliere.net
Signed-off-by: Alex Williamson

eventfd: simplify eventfd_signal()

2023-11-28T13:08:38+00:00

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 
Acked-by: Andrew Donnellan  # ocxl
Acked-by: Eric Farman   # s390
Reviewed-by: Jan Kara 
Reviewed-by: Jens Axboe 
Signed-off-by: Christian Brauner

vfio/mtty: Enable migration support

2023-10-24T21:03:10+00:00

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 
Link: https://lore.kernel.org/r/20231016224736.2575718-3-alex.williamson@redhat.com
Signed-off-by: Alex Williamson

vfio/mtty: Overhaul mtty interrupt handling

2023-10-24T21:02:55+00:00

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 : 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 
Link: https://lore.kernel.org/r/20231016224736.2575718-2-alex.williamson@redhat.com
Signed-off-by: Alex Williamson

vfio: use __aligned_u64 in struct vfio_device_gfx_plane_info

2023-09-28T18:12:08+00:00

The memory layout of struct vfio_device_gfx_plane_info is
architecture-dependent due to a u64 field and a struct size that is not
a multiple of 8 bytes:
- On x86_64 the struct size is padded to a multiple of 8 bytes.
- On x32 the struct size is only a multiple of 4 bytes, not 8.
- Other architectures may vary.

Use __aligned_u64 to make memory layout consistent. This reduces the
chance of 32-bit userspace on a 64-bit kernel breakage.

This patch increases the struct size on x32 but this is safe because of
the struct's argsz field. The kernel may grow the struct as long as it
still supports smaller argsz values from userspace (e.g. applications
compiled against older kernel headers).

Suggested-by: Jason Gunthorpe 
Reviewed-by: Kevin Tian 
Signed-off-by: Stefan Hajnoczi 
Link: https://lore.kernel.org/r/20230918205617.1478722-3-stefanha@redhat.com
Signed-off-by: Alex Williamson

Merge tag 'vfio-v6.6-rc1' of https://github.com/awilliam/linux-vfio

2023-08-31T03:36:01+00:00

Pull VFIO updates from Alex Williamson:

 - VFIO direct character device (cdev) interface support. This extracts
   the vfio device fd from the container and group model, and is
   intended to be the native uAPI for use with IOMMUFD (Yi Liu)

 - Enhancements to the PCI hot reset interface in support of cdev usage
   (Yi Liu)

 - Fix a potential race between registering and unregistering vfio files
   in the kvm-vfio interface and extend use of a lock to avoid extra
   drop and acquires (Dmitry Torokhov)

 - A new vfio-pci variant driver for the AMD/Pensando Distributed
   Services Card (PDS) Ethernet device, supporting live migration (Brett
   Creeley)

 - Cleanups to remove redundant owner setup in cdx and fsl bus drivers,
   and simplify driver init/exit in fsl code (Li Zetao)

 - Fix uninitialized hole in data structure and pad capability
   structures for alignment (Stefan Hajnoczi)

* tag 'vfio-v6.6-rc1' of https://github.com/awilliam/linux-vfio: (53 commits)
  vfio/pds: Send type for SUSPEND_STATUS command
  vfio/pds: fix return value in pds_vfio_get_lm_file()
  pds_core: Fix function header descriptions
  vfio: align capability structures
  vfio/type1: fix cap_migration information leak
  vfio/fsl-mc: Use module_fsl_mc_driver macro to simplify the code
  vfio/cdx: Remove redundant initialization owner in vfio_cdx_driver
  vfio/pds: Add Kconfig and documentation
  vfio/pds: Add support for firmware recovery
  vfio/pds: Add support for dirty page tracking
  vfio/pds: Add VFIO live migration support
  vfio/pds: register with the pds_core PF
  pds_core: Require callers of register/unregister to pass PF drvdata
  vfio/pds: Initial support for pds VFIO driver
  vfio: Commonize combine_ranges for use in other VFIO drivers
  kvm/vfio: avoid bouncing the mutex when adding and deleting groups
  kvm/vfio: ensure kvg instance stays around in kvm_vfio_group_add()
  docs: vfio: Add vfio device cdev description
  vfio: Compile vfio_group infrastructure optionally
  vfio: Move the IOMMU_CAP_CACHE_COHERENCY check in __vfio_register_dev()
  ...