linux-toradex.git/drivers/vfio/vfio.h, branch v6.14-rc2

vfio: replace CONFIG_HAVE_KVM with IS_ENABLED(CONFIG_KVM)

2024-02-08T13:45:35+00:00

It is more accurate to Check if KVM is enabled, instead of having the
architecture say so.  Architectures always "have" KVM, so for example
checking CONFIG_HAVE_KVM in vfio code is pointless, but if KVM is disabled
in a specific build, there is no need for support code.

Alternatively, the #ifdefs could simply be deleted.  However, this
would add dead code.  For example, when KVM is disabled, there is no
need to include code in VFIO that uses symbol_get, as that symbol_get
would always fail.

Cc: Alex Williamson 
Cc: x86@kernel.org
Cc: kbingham@kernel.org
Signed-off-by: Paolo Bonzini

vfio/migration: Add debugfs to live migration driver

2023-12-04T21:29:08+00:00

There are multiple devices, software and operational steps involved
in the process of live migration. An error occurred on any node may
cause the live migration operation to fail.
This complex process makes it very difficult to locate and analyze
the cause when the function fails.

In order to quickly locate the cause of the problem when the
live migration fails, I added a set of debugfs to the vfio
live migration driver.

    +-------------------------------------------+
    |                                           |
    |                                           |
    |                  QEMU                     |
    |                                           |
    |                                           |
    +---+----------------------------+----------+
        |      ^                     |      ^
        |      |                     |      |
        |      |                     |      |
        v      |                     v      |
     +---------+--+               +---------+--+
     |src vfio_dev|               |dst vfio_dev|
     +--+---------+               +--+---------+
        |      ^                     |      ^
        |      |                     |      |
        v      |                     |      |
   +-----------+----+           +-----------+----+
   |src dev debugfs |           |dst dev debugfs |
   +----------------+           +----------------+

The entire debugfs directory will be based on the definition of
the CONFIG_DEBUG_FS macro. If this macro is not enabled, the
interfaces in vfio.h will be empty definitions, and the creation
and initialization of the debugfs directory will not be executed.

   vfio
    |
    +---
    |    +---migration
    |        +--state
    |
    +---
         +---migration
             +--state

debugfs will create a public root directory "vfio" file.
then create a dev_name() file for each live migration device.
First, create a unified state acquisition file of "migration"
in this device directory.
Then, create a public live migration state lookup file "state".

Signed-off-by: Longfang Liu 
Reviewed-by: Cédric Le Goater 
Link: https://lore.kernel.org/r/20231106072225.28577-2-liulongfang@huawei.com
Signed-off-by: Alex Williamson

vfio: Compile vfio_group infrastructure optionally

2023-07-25T16:20:50+00:00

vfio_group is not needed for vfio device cdev, so with vfio device cdev
introduced, the vfio_group infrastructures can be compiled out if only
cdev is needed.

Reviewed-by: Jason Gunthorpe 
Tested-by: Nicolin Chen 
Tested-by: Matthew Rosato 
Tested-by: Yanting Jiang 
Tested-by: Shameer Kolothum 
Tested-by: Terrence Xu 
Tested-by: Zhenzhong Duan 
Signed-off-by: Yi Liu 
Link: https://lore.kernel.org/r/20230718135551.6592-26-yi.l.liu@intel.com
Signed-off-by: Alex Williamson

vfio: Add VFIO_DEVICE_[AT|DE]TACH_IOMMUFD_PT

2023-07-25T16:20:37+00:00

This adds ioctl for userspace to attach device cdev fd to and detach
from IOAS/hw_pagetable managed by iommufd.

    VFIO_DEVICE_ATTACH_IOMMUFD_PT: attach vfio device to IOAS or hw_pagetable
				   managed by iommufd. Attach can be undo
				   by VFIO_DEVICE_DETACH_IOMMUFD_PT or device
				   fd close.
    VFIO_DEVICE_DETACH_IOMMUFD_PT: detach vfio device from the current attached
				   IOAS or hw_pagetable managed by iommufd.

Reviewed-by: Jason Gunthorpe 
Tested-by: Nicolin Chen 
Tested-by: Matthew Rosato 
Tested-by: Yanting Jiang 
Tested-by: Shameer Kolothum 
Tested-by: Terrence Xu 
Tested-by: Zhenzhong Duan 
Signed-off-by: Yi Liu 
Link: https://lore.kernel.org/r/20230718135551.6592-24-yi.l.liu@intel.com
Signed-off-by: Alex Williamson

vfio: Add VFIO_DEVICE_BIND_IOMMUFD

2023-07-25T16:20:32+00:00

This adds ioctl for userspace to bind device cdev fd to iommufd.

    VFIO_DEVICE_BIND_IOMMUFD: bind device to an iommufd, hence gain DMA
			      control provided by the iommufd. open_device
			      op is called after bind_iommufd op.

Tested-by: Nicolin Chen 
Tested-by: Matthew Rosato 
Tested-by: Yanting Jiang 
Tested-by: Shameer Kolothum 
Tested-by: Terrence Xu 
Tested-by: Zhenzhong Duan 
Signed-off-by: Yi Liu 
Reviewed-by: Jason Gunthorpe 
Link: https://lore.kernel.org/r/20230718135551.6592-23-yi.l.liu@intel.com
Signed-off-by: Alex Williamson

vfio: Test kvm pointer in _vfio_device_get_kvm_safe()

2023-07-25T16:19:45+00:00

This saves some lines when adding the kvm get logic for the vfio_device
cdev path.

This also renames _vfio_device_get_kvm_safe() to be vfio_device_get_kvm_safe().

Suggested-by: Jason Gunthorpe 
Reviewed-by: Jason Gunthorpe 
Tested-by: Zhenzhong Duan 
Tested-by: Yanting Jiang 
Signed-off-by: Yi Liu 
Link: https://lore.kernel.org/r/20230718135551.6592-20-yi.l.liu@intel.com
Signed-off-by: Alex Williamson

vfio: Add cdev for vfio_device

2023-07-25T16:19:40+00:00

This adds cdev support for vfio_device. It allows the user to directly
open a vfio device w/o using the legacy container/group interface, as a
prerequisite for supporting new iommu features like nested translation
and etc.

The device fd opened in this manner doesn't have the capability to access
the device as the fops open() doesn't open the device until the successful
VFIO_DEVICE_BIND_IOMMUFD ioctl which will be added in a later patch.

With this patch, devices registered to vfio core would have both the legacy
group and the new device interfaces created.

- group interface : /dev/vfio/$groupID
- device interface: /dev/vfio/devices/vfioX - normal device
		    ("X" is a unique number across vfio devices)

For a given device, the user can identify the matching vfioX by searching
the vfio-dev folder under the sysfs path of the device. Take PCI device
(0000:6a:01.0) as an example, /sys/bus/pci/devices/0000\:6a\:01.0/vfio-dev/vfioX
implies the matching vfioX under /dev/vfio/devices/, and vfio-dev/vfioX/dev
contains the major:minor number of the matching /dev/vfio/devices/vfioX.
The user can get device fd by opening the /dev/vfio/devices/vfioX.

The vfio_device cdev logic in this patch:
*) __vfio_register_dev() path ends up doing cdev_device_add() for each
   vfio_device if VFIO_DEVICE_CDEV configured.
*) vfio_unregister_group_dev() path does cdev_device_del();

cdev interface does not support noiommu devices, so VFIO only creates the
legacy group interface for the physical devices that do not have IOMMU.
noiommu users should use the legacy group interface.

Reviewed-by: Kevin Tian 
Reviewed-by: Jason Gunthorpe 
Tested-by: Terrence Xu 
Tested-by: Nicolin Chen 
Tested-by: Matthew Rosato 
Tested-by: Yanting Jiang 
Tested-by: Shameer Kolothum 
Tested-by: Zhenzhong Duan 
Signed-off-by: Yi Liu 
Link: https://lore.kernel.org/r/20230718135551.6592-19-yi.l.liu@intel.com
Signed-off-by: Alex Williamson

vfio: Record devid in vfio_device_file

2023-07-25T16:19:08+00:00

.bind_iommufd() will generate an ID to represent this bond, which is
needed by userspace for further usage. Store devid in vfio_device_file
to avoid passing the pointer in multiple places.

Reviewed-by: Kevin Tian 
Reviewed-by: Jason Gunthorpe 
Tested-by: Terrence Xu 
Tested-by: Nicolin Chen 
Tested-by: Matthew Rosato 
Tested-by: Yanting Jiang 
Tested-by: Shameer Kolothum 
Tested-by: Zhenzhong Duan 
Signed-off-by: Yi Liu 
Link: https://lore.kernel.org/r/20230718135551.6592-13-yi.l.liu@intel.com
Signed-off-by: Alex Williamson

vfio-iommufd: Split bind/attach into two steps

2023-07-25T16:19:04+00:00

This aligns the bind/attach logic with the coming vfio device cdev support.

Reviewed-by: Kevin Tian 
Reviewed-by: Jason Gunthorpe 
Tested-by: Terrence Xu 
Tested-by: Nicolin Chen 
Tested-by: Matthew Rosato 
Tested-by: Yanting Jiang 
Tested-by: Shameer Kolothum 
Tested-by: Zhenzhong Duan 
Signed-off-by: Yi Liu 
Link: https://lore.kernel.org/r/20230718135551.6592-12-yi.l.liu@intel.com
Signed-off-by: Alex Williamson

vfio-iommufd: Move noiommu compat validation out of vfio_iommufd_bind()

2023-07-25T16:19:01+00:00

This moves the noiommu compat validation logic into vfio_df_group_open().
This is more consistent with what will be done in vfio device cdev path.

Reviewed-by: Kevin Tian 
Reviewed-by: Jason Gunthorpe 
Tested-by: Terrence Xu 
Tested-by: Nicolin Chen 
Tested-by: Matthew Rosato 
Tested-by: Yanting Jiang 
Tested-by: Shameer Kolothum 
Tested-by: Zhenzhong Duan 
Signed-off-by: Yi Liu 
Link: https://lore.kernel.org/r/20230718135551.6592-11-yi.l.liu@intel.com
Signed-off-by: Alex Williamson