vfio: replace CONFIG_HAVE_KVM with IS_ENABLED(CONFIG_KVM)

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 <alex.williamson@redhat.com>
Cc: x86@kernel.org
Cc: kbingham@kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

vfio/migration: Add debugfs to live migration driver

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
|
+---<dev_name1>
| +---migration
| +--state
|
+---<dev_name2>
+---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 <liulongfang@huawei.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/r/20231106072225.28577-2-liulongfang@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Compile vfio_group infrastructure optionally

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 <jgg@nvidia.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-26-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Add VFIO_DEVICE_[AT|DE]TACH_IOMMUFD_PT

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 <jgg@nvidia.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-24-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Add VFIO_DEVICE_BIND_IOMMUFD

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 <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230718135551.6592-23-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Test kvm pointer in _vfio_device_get_kvm_safe()

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 <jgg@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-20-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Add cdev for vfio_device

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 <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-19-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Record devid in vfio_device_file

.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 <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-13-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio-iommufd: Split bind/attach into two steps

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

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-12-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

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

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 <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-11-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Make vfio_df_open() single open for device cdev path

VFIO group has historically allowed multi-open of the device FD. This
was made secure because the "open" was executed via an ioctl to the
group FD which is itself only single open.

However, no known use of multiple device FDs today. It is kind of a
strange thing to do because new device FDs can naturally be created
via dup().

When we implement the new device uAPI (only used in cdev path) there is
no natural way to allow the device itself from being multi-opened in a
secure manner. Without the group FD we cannot prove the security context
of the opener.

Thus, when moving to the new uAPI we block the ability of opening
a device multiple times. Given old group path still allows it we store
a vfio_group pointer in struct vfio_device_file to differentiate.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-10-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Add cdev_device_open_cnt to vfio_group

This is for counting the devices that are opened via the cdev path. This
count is increased and decreased by the cdev path. The group path checks
it to achieve exclusion with the cdev path. With this, only one path
(group path or cdev path) will claim DMA ownership. This avoids scenarios
in which devices within the same group may be opened via different paths.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-9-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Block device access via device fd until device is opened

Allow the vfio_device file to be in a state where the device FD is
opened but the device cannot be used by userspace (i.e. its .open_device()
hasn't been called). This inbetween state is not used when the device
FD is spawned from the group FD, however when we create the device FD
directly by opening a cdev it will be opened in the blocked state.

The reason for the inbetween state is that userspace only gets a FD but
doesn't gain access permission until binding the FD to an iommufd. So in
the blocked state, only the bind operation is allowed. Completing bind
will allow user to further access the device.

This is implemented by adding a flag in struct vfio_device_file to mark
the blocked state and using a simple smp_load_acquire() to obtain the
flag value and serialize all the device setup with the thread accessing
this device.

Following this lockless scheme, it can safely handle the device FD
unbound->bound but it cannot handle bound->unbound. To allow this we'd
need to add a lock on all the vfio ioctls which seems costly. So once
device FD is bound, it remains bound until the FD is closed.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-8-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Pass struct vfio_device_file * to vfio_device_open/close()

This avoids passing too much parameters in multiple functions. Per the
input parameter change, rename the function to be vfio_df_open/close().

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-7-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Accept vfio device file in the KVM facing kAPI

This makes the vfio file kAPIs to accept vfio device files, also a
preparation for vfio device cdev support.

For the kvm set with vfio device file, kvm pointer is stored in struct
vfio_device_file, and use kvm_ref_lock to protect kvm set and kvm
pointer usage within VFIO. This kvm pointer will be set to vfio_device
after device file is bound to iommufd in the cdev path.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-4-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Refine vfio file kAPIs for KVM

This prepares for making the below kAPIs to accept both group file
and device file instead of only vfio group file.

bool vfio_file_enforced_coherent(struct file *file);
void vfio_file_set_kvm(struct file *file, struct kvm *kvm);

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-3-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Allocate per device file structure

This is preparation for adding vfio device cdev support. vfio device
cdev requires:
1) A per device file memory to store the kvm pointer set by KVM. It will
be propagated to vfio_device:kvm after the device cdev file is bound
to an iommufd.
2) A mechanism to block device access through device cdev fd before it
is bound to an iommufd.

To address the above requirements, this adds a per device file structure
named vfio_device_file. For now, it's only a wrapper of struct vfio_device
pointer. Other fields will be added to this per file structure in future
commits.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-2-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: no need to pass kvm pointer during device open

Nothing uses this value during vfio_device_open anymore so it's safe
to remove it.

Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230203215027.151988-3-mjrosato@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: fix deadlock between group lock and kvm lock

After 51cdc8bc120e, we have another deadlock scenario between the
kvm->lock and the vfio group_lock with two different codepaths acquiring
the locks in different order. Specifically in vfio_open_device, vfio
holds the vfio group_lock when issuing device->ops->open_device but some
drivers (like vfio-ap) need to acquire kvm->lock during their open_device
routine; Meanwhile, kvm_vfio_release will acquire the kvm->lock first
before calling vfio_file_set_kvm which will acquire the vfio group_lock.

To resolve this, let's remove the need for the vfio group_lock from the
kvm_vfio_release codepath. This is done by introducing a new spinlock to
protect modifications to the vfio group kvm pointer, and acquiring a kvm
ref from within vfio while holding this spinlock, with the reference held
until the last close for the device in question.

Fixes: 51cdc8bc120e ("kvm/vfio: Fix potential deadlock on vfio group_lock")
Reported-by: Anthony Krowiak <akrowiak@linux.ibm.com>
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230203215027.151988-2-mjrosato@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: revert "iommu driver notify callback"

Revert this dead code:
commit ec5e32940cc9 ("vfio: iommu driver notify callback")

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1675184289-267876-8-git-send-email-steven.sistare@oracle.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Support VFIO_NOIOMMU with iommufd

Add a small amount of emulation to vfio_compat to accept the SET_IOMMU to
VFIO_NOIOMMU_IOMMU and have vfio just ignore iommufd if it is working on a
no-iommu enabled device.

Move the enable_unsafe_noiommu_mode module out of container.c into
vfio_main.c so that it is always available even if VFIO_CONTAINER=n.

This passes Alex's mini-test:

https://github.com/awilliam/tests/blob/master/vfio-noiommu-pci-device-open.c

Link: https://lore.kernel.org/r/0-v3-480cd64a16f7+1ad0-iommufd_noiommu_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

vfio: Fold vfio_virqfd.ko into vfio.ko

This is only 1.8k, putting it in its own module is not really
necessary. The kconfig infrastructure is still there to completely remove
it for systems that are trying for small footprint.

Put it in the main vfio.ko module now that kbuild can support multiple .c
files.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/5-v5-fc5346cacfd4+4c482-vfio_modules_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Move vfio group specific code into group.c

This prepares for compiling out vfio group after vfio device cdev is
added. No vfio_group decode code should be in vfio_main.c, and neither
device->group reference should be in vfio_main.c.

No functional change is intended.

Link: https://lore.kernel.org/r/20221201145535.589687-11-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Yu He <yu.he@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

vfio: Refactor dma APIs for emulated devices

To use group helpers instead of opening group related code in the
API. This prepares moving group specific code out of vfio_main.c.

Link: https://lore.kernel.org/r/20221201145535.589687-10-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

vfio: Make vfio_container optionally compiled

Add a kconfig CONFIG_VFIO_CONTAINER that controls compiling the container
code. If 'n' then only iommufd will provide the container service. All the
support for vfio iommu drivers, including type1, will not be built.

This allows a compilation check that no inappropriate dependencies between
the device/group and container have been created.

Link: https://lore.kernel.org/r/9-v4-42cd2eb0e3eb+335a-vfio_iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

vfio-iommufd: Support iommufd for emulated VFIO devices

Emulated VFIO devices are calling vfio_register_emulated_iommu_dev() and
consist of all the mdev drivers.

Like the physical drivers, support for iommufd is provided by the driver
supplying the correct standard ops. Provide ops from the core that
duplicate what vfio_register_emulated_iommu_dev() does.

Emulated drivers are where it is more likely to see variation in the
iommfd support ops. For instance IDXD will probably need to setup both a
iommfd_device context linked to a PASID and an iommufd_access context to
support all their mdev operations.

Link: https://lore.kernel.org/r/7-v4-42cd2eb0e3eb+335a-vfio_iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

vfio-iommufd: Support iommufd for physical VFIO devices

This creates the iommufd_device for the physical VFIO drivers. These are
all the drivers that are calling vfio_register_group_dev() and expect the
type1 code to setup a real iommu_domain against their parent struct
device.

The design gives the driver a choice in how it gets connected to iommufd
by providing bind_iommufd/unbind_iommufd/attach_ioas callbacks to
implement as required. The core code provides three default callbacks for
physical mode using a real iommu_domain. This is suitable for drivers
using vfio_register_group_dev()

Link: https://lore.kernel.org/r/6-v4-42cd2eb0e3eb+335a-vfio_iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

vfio-iommufd: Allow iommufd to be used in place of a container fd

This makes VFIO_GROUP_SET_CONTAINER accept both a vfio container FD and an
iommufd.

In iommufd mode an IOAS will exist after the SET_CONTAINER, but it will
not be attached to any groups.

For VFIO this means that the VFIO_GROUP_GET_STATUS and
VFIO_GROUP_FLAGS_VIABLE works subtly differently. With the container FD
the iommu_group_claim_dma_owner() is done during SET_CONTAINER but for
IOMMUFD this is done during VFIO_GROUP_GET_DEVICE_FD. Meaning that
VFIO_GROUP_FLAGS_VIABLE could be set but GET_DEVICE_FD will fail due to
viability.

As GET_DEVICE_FD can fail for many reasons already this is not expected to
be a meaningful difference.

Reorganize the tests for if the group has an assigned container or iommu
into a vfio_group_has_iommu() function and consolidate all the duplicated
WARN_ON's etc related to this.

Call container functions only if a container is actually present on the
group.

Link: https://lore.kernel.org/r/5-v4-42cd2eb0e3eb+335a-vfio_iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

vfio: Use IOMMU_CAP_ENFORCE_CACHE_COHERENCY for vfio_file_enforced_coherent()

iommufd doesn't establish the iommu_domains until after the device FD is
opened, even if the container has been set. This design is part of moving
away from the group centric iommu APIs.

This is fine, except that the normal sequence of establishing the kvm
wbinvd won't work:

group = open("/dev/vfio/XX")
ioctl(group, VFIO_GROUP_SET_CONTAINER)
ioctl(kvm, KVM_DEV_VFIO_GROUP_ADD)
ioctl(group, VFIO_GROUP_GET_DEVICE_FD)

As the domains don't start existing until GET_DEVICE_FD. Further,
GET_DEVICE_FD requires that KVM_DEV_VFIO_GROUP_ADD already be done as that
is what sets the group->kvm and thus device->kvm for the driver to use
during open.

Now that we have device centric cap ops and the new
IOMMU_CAP_ENFORCE_CACHE_COHERENCY we know what the iommu_domain will be
capable of without having to create it. Use this to compute
vfio_file_enforced_coherent() and resolve the ordering problems.

VFIO always tries to upgrade domains to enforce cache coherency, it never
attaches a device that supports enforce cache coherency to a less capable
domain, so the cap test is a sufficient proxy for the ultimate
outcome. iommufd also ensures that devices that set the cap will be
connected to enforcing domains.

Link: https://lore.kernel.org/r/4-v4-42cd2eb0e3eb+335a-vfio_iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

vfio: Rename vfio_device_assign/unassign_container()

These functions don't really assign anything anymore, they just increment
some refcounts and do a sanity check. Call them
vfio_group_[un]use_container()

Link: https://lore.kernel.org/r/3-v4-42cd2eb0e3eb+335a-vfio_iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yu He <yu.he@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

vfio: Make the group FD disassociate from the iommu_group

Allow the vfio_group struct to exist with a NULL iommu_group pointer. When
the pointer is NULL the vfio_group users promise not to touch the
iommu_group. This allows a driver to be hot unplugged while userspace is
keeping the group FD open.

Remove all the code waiting for the group FD to close.

This fixes a userspace regression where we learned that virtnodedevd
leaves a group FD open even though the /dev/ node for it has been deleted
and all the drivers for it unplugged.

Fixes: ca5f21b25749 ("vfio: Follow a strict lifetime for struct iommu_group")
Reported-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/3-v2-15417f29324e+1c-vfio_group_disassociate_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Change vfio_group->group_rwsem to a mutex

These days not much is using the read side:
- device first open
- ioctl_get_status
- device FD release
- check enforced_coherent

None of this is performance, so just make it into a normal mutex.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/2-v1-917e3647f123+b1a-vfio_group_users_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Remove the vfio_group->users and users_comp

Kevin points out that the users is really just tracking if
group->opened_file is set, so we can simplify this code to a wait_queue
that looks for !opened_file under the group_rwsem.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/1-v1-917e3647f123+b1a-vfio_group_users_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Follow a strict lifetime for struct iommu_group

The iommu_group comes from the struct device that a driver has been bound
to and then created a struct vfio_device against. To keep the iommu layer
sane we want to have a simple rule that only an attached driver should be
using the iommu API. Particularly only an attached driver should hold
ownership.

In VFIO's case since it uses the group APIs and it shares between
different drivers it is a bit more complicated, but the principle still
holds.

Solve this by waiting for all users of the vfio_group to stop before
allowing vfio_unregister_group_dev() to complete. This is done with a new
completion to know when the users go away and an additional refcount to
keep track of how many device drivers are sharing the vfio group. The last
driver to be unregistered will clean up the group.

This solves crashes in the S390 iommu driver that come because VFIO ends
up racing releasing ownership (which attaches the default iommu_domain to
the device) with the removal of that same device from the iommu
driver. This is a side case that iommu drivers should not have to cope
with.

iommu driver failed to attach the default/blocking domain
WARNING: CPU: 0 PID: 5082 at drivers/iommu/iommu.c:1961 iommu_detach_group+0x6c/0x80
Modules linked in: macvtap macvlan tap vfio_pci vfio_pci_core irqbypass vfio_virqfd kvm nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables nfnetlink mlx5_ib sunrpc ib_uverbs ism smc uvdevice ib_core s390_trng eadm_sch tape_3590 tape tape_class vfio_ccw mdev vfio_iommu_type1 vfio zcrypt_cex4 sch_fq_codel configfs ghash_s390 prng chacha_s390 libchacha aes_s390 mlx5_core des_s390 libdes sha3_512_s390 nvme sha3_256_s390 sha512_s390 sha256_s390 sha1_s390 sha_common nvme_core zfcp scsi_transport_fc pkey zcrypt rng_core autofs4
CPU: 0 PID: 5082 Comm: qemu-system-s39 Tainted: G W 6.0.0-rc3 #5
Hardware name: IBM 3931 A01 782 (LPAR)
Krnl PSW : 0704c00180000000 000000095bb10d28 (iommu_detach_group+0x70/0x80)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
Krnl GPRS: 0000000000000001 0000000900000027 0000000000000039 000000095c97ffe0
00000000fffeffff 00000009fc290000 00000000af1fda50 00000000af590b58
00000000af1fdaf0 0000000135c7a320 0000000135e52258 0000000135e52200
00000000a29e8000 00000000af590b40 000000095bb10d24 0000038004b13c98
Krnl Code: 000000095bb10d18: c020003d56fc larl %r2,000000095c2bbb10
000000095bb10d1e: c0e50019d901 brasl %r14,000000095be4bf20
#000000095bb10d24: af000000 mc 0,0
>000000095bb10d28: b904002a lgr %r2,%r10
000000095bb10d2c: ebaff0a00004 lmg %r10,%r15,160(%r15)
000000095bb10d32: c0f4001aa867 brcl 15,000000095be65e00
000000095bb10d38: c004002168e0 brcl 0,000000095bf3def8
000000095bb10d3e: eb6ff0480024 stmg %r6,%r15,72(%r15)
Call Trace:
[<000000095bb10d28>] iommu_detach_group+0x70/0x80
([<000000095bb10d24>] iommu_detach_group+0x6c/0x80)
[<000003ff80243b0e>] vfio_iommu_type1_detach_group+0x136/0x6c8 [vfio_iommu_type1]
[<000003ff80137780>] __vfio_group_unset_container+0x58/0x158 [vfio]
[<000003ff80138a16>] vfio_group_fops_unl_ioctl+0x1b6/0x210 [vfio]
pci 0004:00:00.0: Removing from iommu group 4
[<000000095b5b62e8>] __s390x_sys_ioctl+0xc0/0x100
[<000000095be5d3b4>] __do_syscall+0x1d4/0x200
[<000000095be6c072>] system_call+0x82/0xb0
Last Breaking-Event-Address:
[<000000095be4bf80>] __warn_printk+0x60/0x68

It indicates that domain->ops->attach_dev() failed because the driver has
already passed the point of destructing the device.

Fixes: 9ac8545199a1 ("iommu: Fix use-after-free in iommu_release_device")
Reported-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/0-v2-a3c5f4429e2a+55-iommu_group_lifetime_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Move container code into drivers/vfio/container.c

All the functions that dereference struct vfio_container are moved into
container.c.

Simple code motion, no functional change.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/8-v3-297af71838d2+b9-vfio_container_split_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Add header guards and includes to drivers/vfio/vfio.h

As is normal for headers.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v3-297af71838d2+b9-vfio_container_split_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Replace phys_pfn with pages for vfio_pin_pages()

Most of the callers of vfio_pin_pages() want "struct page *" and the
low-level mm code to pin pages returns a list of "struct page *" too.
So there's no gain in converting "struct page *" to PFN in between.

Replace the output parameter "phys_pfn" list with a "pages" list, to
simplify callers. This also allows us to replace the vfio_iommu_type1
implementation with a more efficient one.

And drop the pfn_valid check in the gvt code, as there is no need to
do such a check at a page-backed struct page pointer.

For now, also update vfio_iommu_type1 to fit this new parameter too.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-11-nicolinc@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Pass in starting IOVA to vfio_pin/unpin_pages API

The vfio_pin/unpin_pages() so far accepted arrays of PFNs of user IOVA.
Among all three callers, there was only one caller possibly passing in
a non-contiguous PFN list, which is now ensured to have contiguous PFN
inputs too.

Pass in the starting address with "iova" alone to simplify things, so
callers no longer need to maintain a PFN list or to pin/unpin one page
at a time. This also allows VFIO to use more efficient implementations
of pin/unpin_pages.

For now, also update vfio_iommu_type1 to fit this new parameter too,
while keeping its input intact (being user_iova) since we don't want
to spend too much effort swapping its parameters and local variables
at that level.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-6-nicolinc@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Make vfio_unpin_pages() return void

There's only one caller that checks its return value with a WARN_ON_ONCE,
while all other callers don't check the return value at all. Above that,
an undo function should not fail. So, simplify the API to return void by
embedding similar WARN_ONs.

Also for users to pinpoint which condition fails, separate WARN_ON lines,
yet remove the "driver->ops->unpin_pages" check, since it's unreasonable
for callers to unpin on something totally random that wasn't even pinned.
And remove NULL pointer checks for they would trigger oops vs. warnings.
Note that npage is already validated in the vfio core, thus drop the same
check in the type1 code.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/20220723020256.30081-2-nicolinc@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Replace the iommu notifier with a device list

Instead of bouncing the function call to the driver op through a blocking
notifier just have the iommu layer call it directly.

Register each device that is being attached to the iommu with the lower
driver which then threads them on a linked list and calls the appropriate
driver op at the right time.

Currently the only use is if dma_unmap() is defined.

Also, fully lock all the debugging tests on the pinning path that a
dma_unmap is registered.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/2-v4-681e038e30fd+78-vfio_unmap_notif_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: Replace the DMA unmapping notifier with a callback

Instead of having drivers register the notifier with explicit code just
have them provide a dma_unmap callback op in their driver ops and rely on
the core code to wire it up.

Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v4-681e038e30fd+78-vfio_unmap_notif_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: clean up the check for mediated device in vfio_iommu_type1

Pass the group flags to ->attach_group and remove the messy check for
the bus type.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20210924155705.4258-12-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

vfio: move the vfio_iommu_driver_ops interface out of <linux/vfio.h>

Create a new private drivers/vfio/vfio.h header for the interface between
the VFIO core and the iommu drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20210924155705.4258-10-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>