Commit Graph

9 Commits

Author SHA1 Message Date
Yi Liu 8da7a0e79f 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>
2022-12-05 08:56:01 -04:00
Jason Gunthorpe 81ab9890da vfio: Move container related MODULE_ALIAS statements into container.c
The miscdev is in container.c, so should these related MODULE_ALIAS
statements. This is necessary for the next patch to be able to fully
disable /dev/vfio/vfio.

Fixes: cdc71fe4ec ("vfio: Move container code into drivers/vfio/container.c")
Link: https://lore.kernel.org/r/8-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: 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>
Reported-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-12-02 11:52:04 -04:00
Jason Gunthorpe 4741f2e941 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>
2022-12-02 11:52:03 -04:00
Jason Gunthorpe 2a3dab19a0 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>
2022-12-02 11:52:03 -04:00
Jason Gunthorpe 0d8227b622 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>
2022-12-02 11:52:03 -04:00
Jason Gunthorpe 04f930c3e4 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>
2022-12-02 11:52:03 -04:00
Jason Gunthorpe bab6fabc01 vfio: Move vfio_device_assign_container() into vfio_device_first_open()
The only thing this function does is assert the group has an assigned
container and incrs refcounts.

The overall model we have is that once a container_users refcount is
incremented it cannot be de-assigned from the group -
vfio_group_ioctl_unset_container() will fail and the group FD cannot be
closed.

Thus we do not need to check this on every device FD open, just the
first. Reorganize the code so that only the first open and last close
manages the container.

Link: https://lore.kernel.org/r/2-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>
2022-12-02 11:52:03 -04:00
Jason Gunthorpe c82e81ab25 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>
2022-10-04 12:06:58 -06:00
Jason Gunthorpe cdc71fe4ec 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>
2022-09-22 15:46:06 -06:00