Commit Graph

13 Commits

Author SHA1 Message Date
Linus Torvalds cac85e4616 VFIO updates for v6.3-rc1
- Remove redundant resource check in vfio-platform. (Angus Chen)
 
  - Use GFP_KERNEL_ACCOUNT for persistent userspace allocations, allowing
    removal of arbitrary kernel limits in favor of cgroup control.
    (Yishai Hadas)
 
  - mdev tidy-ups, including removing the module-only build restriction
    for sample drivers, Kconfig changes to select mdev support,
    documentation movement to keep sample driver usage instructions with
    sample drivers rather than with API docs, remove references to
    out-of-tree drivers in docs. (Christoph Hellwig)
 
  - Fix collateral breakages from mdev Kconfig changes. (Arnd Bergmann)
 
  - Make mlx5 migration support match device support, improve source
    and target flows to improve pre-copy support and reduce downtime.
    (Yishai Hadas)
 
  - Convert additional mdev sysfs case to use sysfs_emit(). (Bo Liu)
 
  - Resolve copy-paste error in mdev mbochs sample driver Kconfig.
    (Ye Xingchen)
 
  - Avoid propagating missing reset error in vfio-platform if reset
    requirement is relaxed by module option. (Tomasz Duszynski)
 
  - Range size fixes in mlx5 variant driver for missed last byte and
    stricter range calculation. (Yishai Hadas)
 
  - Fixes to suspended vaddr support and locked_vm accounting, excluding
    mdev configurations from the former due to potential to indefinitely
    block kernel threads, fix underflow and restore locked_vm on new mm.
    (Steve Sistare)
 
  - Update outdated vfio documentation due to new IOMMUFD interfaces in
    recent kernels. (Yi Liu)
 
  - Resolve deadlock between group_lock and kvm_lock, finally.
    (Matthew Rosato)
 
  - Fix NULL pointer in group initialization error path with IOMMUFD.
    (Yan Zhao)
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Merge tag 'vfio-v6.3-rc1' of https://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - Remove redundant resource check in vfio-platform (Angus Chen)

 - Use GFP_KERNEL_ACCOUNT for persistent userspace allocations, allowing
   removal of arbitrary kernel limits in favor of cgroup control (Yishai
   Hadas)

 - mdev tidy-ups, including removing the module-only build restriction
   for sample drivers, Kconfig changes to select mdev support,
   documentation movement to keep sample driver usage instructions with
   sample drivers rather than with API docs, remove references to
   out-of-tree drivers in docs (Christoph Hellwig)

 - Fix collateral breakages from mdev Kconfig changes (Arnd Bergmann)

 - Make mlx5 migration support match device support, improve source and
   target flows to improve pre-copy support and reduce downtime (Yishai
   Hadas)

 - Convert additional mdev sysfs case to use sysfs_emit() (Bo Liu)

 - Resolve copy-paste error in mdev mbochs sample driver Kconfig (Ye
   Xingchen)

 - Avoid propagating missing reset error in vfio-platform if reset
   requirement is relaxed by module option (Tomasz Duszynski)

 - Range size fixes in mlx5 variant driver for missed last byte and
   stricter range calculation (Yishai Hadas)

 - Fixes to suspended vaddr support and locked_vm accounting, excluding
   mdev configurations from the former due to potential to indefinitely
   block kernel threads, fix underflow and restore locked_vm on new mm
   (Steve Sistare)

 - Update outdated vfio documentation due to new IOMMUFD interfaces in
   recent kernels (Yi Liu)

 - Resolve deadlock between group_lock and kvm_lock, finally (Matthew
   Rosato)

 - Fix NULL pointer in group initialization error path with IOMMUFD (Yan
   Zhao)

* tag 'vfio-v6.3-rc1' of https://github.com/awilliam/linux-vfio: (32 commits)
  vfio: Fix NULL pointer dereference caused by uninitialized group->iommufd
  docs: vfio: Update vfio.rst per latest interfaces
  vfio: Update the kdoc for vfio_device_ops
  vfio/mlx5: Fix range size calculation upon tracker creation
  vfio: no need to pass kvm pointer during device open
  vfio: fix deadlock between group lock and kvm lock
  vfio: revert "iommu driver notify callback"
  vfio/type1: revert "implement notify callback"
  vfio/type1: revert "block on invalid vaddr"
  vfio/type1: restore locked_vm
  vfio/type1: track locked_vm per dma
  vfio/type1: prevent underflow of locked_vm via exec()
  vfio/type1: exclude mdevs from VFIO_UPDATE_VADDR
  vfio: platform: ignore missing reset if disabled at module init
  vfio/mlx5: Improve the target side flow to reduce downtime
  vfio/mlx5: Improve the source side flow upon pre_copy
  vfio/mlx5: Check whether VF is migratable
  samples: fix the prompt about SAMPLE_VFIO_MDEV_MBOCHS
  vfio/mdev: Use sysfs_emit() to instead of sprintf()
  vfio-mdev: add back CONFIG_VFIO dependency
  ...
2023-02-25 11:52:57 -08:00
Steve Sistare e592296cd6 vfio: revert "iommu driver notify callback"
Revert this dead code:
  commit ec5e32940c ("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>
2023-02-09 11:39:14 -07:00
Jason Gunthorpe c9a397cee9 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>
2023-02-03 15:45:23 -04:00
Jason Gunthorpe 0886196ca8 vfio: Use GFP_KERNEL_ACCOUNT for userspace persistent allocations
Use GFP_KERNEL_ACCOUNT for userspace persistent allocations.

The GFP_KERNEL_ACCOUNT option lets the memory allocator know that this
is untrusted allocation triggered from userspace and should be a subject
of kmem accounting, and as such it is controlled by the cgroup
mechanism.

The way to find the relevant allocations was for example to look at the
close_device function and trace back all the kfrees to their
allocations.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230108154427.32609-4-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-01-23 11:26:29 -07:00
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