Commit Graph

90 Commits

Author SHA1 Message Date
Jason Gunthorpe
13fbceb1b8 iommufd: Convert to alloc_domain_paging()
Move the global static blocked domain to the ops and convert the unmanaged
domain to domain_alloc_paging.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Sven Peter <sven@svenpeter.dev>
Link: https://lore.kernel.org/r/4-v2-bff223cf6409+282-dart_paging_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2023-10-26 16:53:50 +02:00
Jason Gunthorpe
1c68cbc64f iommu: Add IOMMU_DOMAIN_PLATFORM
This is used when the iommu driver is taking control of the dma_ops,
currently only on S390 and power spapr. It is designed to preserve the
original ops->detach_dev() semantic that these S390 was built around.

Provide an opaque domain type and a 'default_domain' ops value that allows
the driver to trivially force any single domain as the default domain.

Update iommufd selftest to use this instead of set_platform_dma_ops

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/2-v8-81230027b2fa+9d-iommu_all_defdom_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2023-09-25 11:40:52 +02:00
Jason Gunthorpe
df31b29847 iommu: Add iommu_ops->identity_domain
This allows a driver to set a global static to an IDENTITY domain and
the core code will automatically use it whenever an IDENTITY domain
is requested.

By making it always available it means the IDENTITY can be used in error
handling paths to force the iommu driver into a known state. Devices
implementing global static identity domains should avoid failing their
attach_dev ops.

To make global static domains simpler allow drivers to omit their free
function and update the iommufd selftest.

Convert rockchip to use the new mechanism.

Tested-by: Steven Price <steven.price@arm.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v8-81230027b2fa+9d-iommu_all_defdom_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2023-09-25 11:40:51 +02:00
Linus Torvalds
4debf77169 iommufd for 6.6
This includes a shared branch with VFIO:
 
  - Enhance VFIO_DEVICE_GET_PCI_HOT_RESET_INFO so it can work with iommufd
    FDs, not just group FDs. This removes the last place in the uAPI that
    required the group fd.
 
  - Give VFIO a new device node /dev/vfio/devices/vfioX (the so called cdev
    node) which is very similar to the FD from VFIO_GROUP_GET_DEVICE_FD.
    The cdev is associated with the struct device that the VFIO driver is
    bound to and shows up in sysfs in the normal way.
 
  - Add a cdev IOCTL VFIO_DEVICE_BIND_IOMMUFD which allows a newly opened
    /dev/vfio/devices/vfioX to be associated with an IOMMUFD, this replaces
    the VFIO_GROUP_SET_CONTAINER flow.
 
  - Add cdev IOCTLs VFIO_DEVICE_[AT|DE]TACH_IOMMUFD_PT to allow the IOMMU
    translation the vfio_device is associated with to be changed. This is a
    significant new feature for VFIO as previously each vfio_device was
    fixed to a single translation.
 
    The translation is under the control of iommufd, so it can be any of
    the different translation modes that iommufd is learning to create.
 
 At this point VFIO has compilation options to remove the legacy interfaces
 and in modern mode it behaves like a normal driver subsystem. The
 /dev/vfio/iommu and /dev/vfio/groupX nodes are not present and each
 vfio_device only has a /dev/vfio/devices/vfioX cdev node that represents
 the device.
 
 On top of this is built some of the new iommufd functionality:
 
  - IOMMU_HWPT_ALLOC allows userspace to directly create the low level
    IO Page table objects and affiliate them with IOAS objects that hold
    the translation mapping. This is the basic functionality for the
    normal IOMMU_DOMAIN_PAGING domains.
 
  - VFIO_DEVICE_ATTACH_IOMMUFD_PT can be used to replace the current
    translation. This is wired up to through all the layers down to the
    driver so the driver has the ability to implement a hitless
    replacement. This is necessary to fully support guest behaviors when
    emulating HW (eg guest atomic change of translation)
 
  - IOMMU_GET_HW_INFO returns information about the IOMMU driver HW that
    owns a VFIO device. This includes support for the Intel iommu, and
    patches have been posted for all the other server IOMMU.
 
 Along the way are a number of internal items:
 
  - New iommufd kapis iommufd_ctx_has_group(), iommufd_device_to_ictx(),
    iommufd_device_to_id(), iommufd_access_detach(), iommufd_ctx_from_fd(),
    iommufd_device_replace()
 
  - iommufd now internally tracks iommu_groups as it needs some per-group
    data
 
  - Reorganize how the internal hwpt allocation flows to have more robust
    locking
 
  - Improve the access interfaces to support detach and replace of an IOAS
    from an access
 
  - New selftests and a rework of how the selftests creates a mock iommu
    driver to be more like a real iommu driver
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Merge tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd

Pull iommufd updates from Jason Gunthorpe:
 "On top of the vfio updates is built some new iommufd functionality:

   - IOMMU_HWPT_ALLOC allows userspace to directly create the low level
     IO Page table objects and affiliate them with IOAS objects that
     hold the translation mapping. This is the basic functionality for
     the normal IOMMU_DOMAIN_PAGING domains.

   - VFIO_DEVICE_ATTACH_IOMMUFD_PT can be used to replace the current
     translation. This is wired up to through all the layers down to the
     driver so the driver has the ability to implement a hitless
     replacement. This is necessary to fully support guest behaviors
     when emulating HW (eg guest atomic change of translation)

   - IOMMU_GET_HW_INFO returns information about the IOMMU driver HW
     that owns a VFIO device. This includes support for the Intel iommu,
     and patches have been posted for all the other server IOMMU.

  Along the way are a number of internal items:

   - New iommufd kernel APIs: iommufd_ctx_has_group(),
        iommufd_device_to_ictx(), iommufd_device_to_id(),
        iommufd_access_detach(), iommufd_ctx_from_fd(),
        iommufd_device_replace()

   - iommufd now internally tracks iommu_groups as it needs some
     per-group data

   - Reorganize how the internal hwpt allocation flows to have more
     robust locking

   - Improve the access interfaces to support detach and replace of an
     IOAS from an access

   - New selftests and a rework of how the selftests creates a mock
     iommu driver to be more like a real iommu driver"

Link: https://lore.kernel.org/lkml/ZO%2FTe6LU1ENf58ZW@nvidia.com/

* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd: (34 commits)
  iommufd/selftest: Don't leak the platform device memory when unloading the module
  iommu/vt-d: Implement hw_info for iommu capability query
  iommufd/selftest: Add coverage for IOMMU_GET_HW_INFO ioctl
  iommufd: Add IOMMU_GET_HW_INFO
  iommu: Add new iommu op to get iommu hardware information
  iommu: Move dev_iommu_ops() to private header
  iommufd: Remove iommufd_ref_to_users()
  iommufd/selftest: Make the mock iommu driver into a real driver
  vfio: Support IO page table replacement
  iommufd/selftest: Add IOMMU_TEST_OP_ACCESS_REPLACE_IOAS coverage
  iommufd: Add iommufd_access_replace() API
  iommufd: Use iommufd_access_change_ioas in iommufd_access_destroy_object
  iommufd: Add iommufd_access_change_ioas(_id) helpers
  iommufd: Allow passing in iopt_access_list_id to iopt_remove_access()
  vfio: Do not allow !ops->dma_unmap in vfio_pin/unpin_pages()
  iommufd/selftest: Add a selftest for IOMMU_HWPT_ALLOC
  iommufd/selftest: Return the real idev id from selftest mock_domain
  iommufd: Add IOMMU_HWPT_ALLOC
  iommufd/selftest: Test iommufd_device_replace()
  iommufd: Make destroy_rwsem use a lock class per object type
  ...
2023-08-30 20:41:37 -07:00
Linus Torvalds
ec0e2dc810 VFIO updates for v6.6-rc1
- 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)
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Merge tag 'vfio-v6.6-rc1' of https://github.com/awilliam/linux-vfio

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()
  ...
2023-08-30 20:36:01 -07:00
Yang Yingliang
eb501c2d96 iommufd/selftest: Don't leak the platform device memory when unloading the module
It should call platform_device_unregister() instead of
platform_device_del() to unregister and free the device.

Fixes: 23a1b46f15 ("iommufd/selftest: Make the mock iommu driver into a real driver")
Link: https://lore.kernel.org/r/20230816081318.1232865-1-yangyingliang@huawei.com
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-08-18 12:56:24 -03:00
Nicolin Chen
af4fde93c3 iommufd/selftest: Add coverage for IOMMU_GET_HW_INFO ioctl
Add a mock_domain_hw_info function and an iommu_test_hw_info data
structure. This allows to test the IOMMU_GET_HW_INFO ioctl passing the
test_reg value for the mock_dev.

Link: https://lore.kernel.org/r/20230818101033.4100-5-yi.l.liu@intel.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-08-18 12:52:15 -03:00
Yi Liu
55dd4023ce iommufd: Add IOMMU_GET_HW_INFO
Under nested IOMMU translation, userspace owns the stage-1 translation
table (e.g. the stage-1 page table of Intel VT-d or the context table of
ARM SMMUv3, and etc.). Stage-1 translation tables are vendor specific, and
need to be compatible with the underlying IOMMU hardware. Hence, userspace
should know the IOMMU hardware capability before creating and configuring
the stage-1 translation table to kernel.

This adds IOMMU_GET_HW_INFO ioctl to query the IOMMU hardware information
(a.k.a capability) for a given device. The returned data is vendor
specific, userspace needs to decode it with the structure by the output
@out_data_type field.

As only physical devices have IOMMU hardware, so this will return error if
the given device is not a physical device.

Link: https://lore.kernel.org/r/20230818101033.4100-4-yi.l.liu@intel.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Co-developed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-08-18 12:52:15 -03:00
Stefan Hajnoczi
a881b49694 vfio: align capability structures
The VFIO_DEVICE_GET_INFO, VFIO_DEVICE_GET_REGION_INFO, and
VFIO_IOMMU_GET_INFO ioctls fill in an info struct followed by capability
structs:

  +------+---------+---------+-----+
  | info | caps[0] | caps[1] | ... |
  +------+---------+---------+-----+

Both the info and capability struct sizes are not always multiples of
sizeof(u64), leaving u64 fields in later capability structs misaligned.

Userspace applications currently need to handle misalignment manually in
order to support CPU architectures and programming languages with strict
alignment requirements.

Make life easier for userspace by ensuring alignment in the kernel. This
is done by padding info struct definitions and by copying out zeroes
after capability structs that are not aligned.

The new layout is as follows:

  +------+---------+---+---------+-----+
  | info | caps[0] | 0 | caps[1] | ... |
  +------+---------+---+---------+-----+

In this example caps[0] has a size that is not multiples of sizeof(u64),
so zero padding is added to align the subsequent structure.

Adding zero padding between structs does not break the uapi. The memory
layout is specified by the info.cap_offset and caps[i].next fields
filled in by the kernel. Applications use these field values to locate
structs and are therefore unaffected by the addition of zero padding.

Note that code that copies out info structs with padding is updated to
always zero the struct and copy out as many bytes as userspace
requested. This makes the code shorter and avoids potential information
leaks by ensuring padding is initialized.

Originally-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230809203144.2880050-1-stefanha@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-08-17 12:17:44 -06:00
Jason Gunthorpe
65aaca1134 iommufd: Remove iommufd_ref_to_users()
This no longer has any callers, remove the function

Kevin noticed that after commit 99f98a7c0d ("iommufd: IOMMUFD_DESTROY
should not increase the refcount") there was only one other user and it
turns out the rework in commit 9227da7816 ("iommufd: Add
iommufd_access_change_ioas(_id) helpers") got rid of the last one.

Link: https://lore.kernel.org/r/0-v1-abb31bedd888+c1-iommufd_ref_to_users_jgg@nvidia.com
Suggested-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-08-15 10:03:14 -03:00
Jason Gunthorpe
a35762dd14 Linux 6.5-rc6
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Merge tag 'v6.5-rc6' into iommufd for-next

Required for following patches.

Resolve merge conflict by using the hunk from the for-next branch and
shifting the iommufd_object_deref_user() into iommufd_hw_pagetable_put()

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-08-15 10:01:26 -03:00
Jason Gunthorpe
23a1b46f15 iommufd/selftest: Make the mock iommu driver into a real driver
I've avoided doing this because there is no way to make this happen
without an intrusion into the core code. Up till now this has avoided
needing the core code's probe path with some hackery - but now that
default domains are becoming mandatory it is unavoidable.

This became a serious problem when the core code stopped allowing
partially registered iommu drivers in commit 14891af379 ("iommu: Move
the iommu driver sysfs setup into iommu_init/deinit_device()") which
breaks the selftest. That series was developed along with a second series
that contained this patch so it was not noticed.

Make it so that iommufd selftest can create a real iommu driver and bind
it only to is own private bus. Add iommu_device_register_bus() as a core
code helper to make this possible. It simply sets the right pointers and
registers the notifier block. The mock driver then works like any normal
driver should, with probe triggered by the bus ops

When the bus->iommu_ops stuff is fully unwound we can probably do better
here and remove this special case.

Link: https://lore.kernel.org/r/15-v6-e8114faedade+425-iommu_all_defdom_jgg@nvidia.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-08-14 20:13:45 -03:00
Nicolin Chen
c154660b6e iommufd/selftest: Add IOMMU_TEST_OP_ACCESS_REPLACE_IOAS coverage
Add a new IOMMU_TEST_OP_ACCESS_REPLACE_IOAS to allow replacing the
access->ioas, corresponding to the iommufd_access_replace() helper.

Then add replace coverage as a part of user_copy test case, which
basically repeats the copy test after replacing the old ioas with a new
one.

Link: https://lore.kernel.org/r/a4897f93d41c34b972213243b8dbf4c3832842e4.1690523699.git.nicolinc@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-28 13:31:24 -03:00
Nicolin Chen
70c16123d8 iommufd: Add iommufd_access_replace() API
Taking advantage of the new iommufd_access_change_ioas_id helper, add an
iommufd_access_replace() API for the VFIO emulated pathway to use.

Link: https://lore.kernel.org/r/a3267b924fd5f45e0d3a1dd13a9237e923563862.1690523699.git.nicolinc@nvidia.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-28 13:31:24 -03:00
Nicolin Chen
6129b59fcd iommufd: Use iommufd_access_change_ioas in iommufd_access_destroy_object
Update iommufd_access_destroy_object() to call the new
iommufd_access_change_ioas() helper.

It is impossible to legitimately race iommufd_access_destroy_object() with
iommufd_access_change_ioas() as iommufd_access_destroy_object() is only
called once the refcount reache zero, so any concurrent
iommufd_access_change_ioas() is already UAFing the memory.

Link: https://lore.kernel.org/r/f9fbeca2cde7f8515da18d689b3e02a6a40a5e14.1690523699.git.nicolinc@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-28 13:31:24 -03:00
Nicolin Chen
9227da7816 iommufd: Add iommufd_access_change_ioas(_id) helpers
The complication of the mutex and refcount will be amplified after we
introduce the replace support for accesses. So, add a preparatory change
of a constitutive helper iommufd_access_change_ioas() and its wrapper
iommufd_access_change_ioas_id(). They can simply take care of existing
iommufd_access_attach() and iommufd_access_detach(), properly sequencing
the refcount puts so that they are truely at the end of the sequence after
we know the IOAS pointer is not required any more.

Link: https://lore.kernel.org/r/da0c462532193b447329c4eb975a596f47e49b70.1690523699.git.nicolinc@nvidia.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-28 13:31:24 -03:00
Nicolin Chen
5d5c85ff62 iommufd: Allow passing in iopt_access_list_id to iopt_remove_access()
This is a preparatory change for ioas replacement support for accesses.
The replacement routine does an iopt_add_access() for a new IOAS first and
then iopt_remove_access() for the old IOAS upon the success of the first
call. However, the first call overrides the iopt_access_list_id in the
access struct, resulting in iopt_remove_access() being unable to work on
the old IOAS.

Add an iopt_access_list_id as a parameter to iopt_remove_access, so the
replacement routine can save the id before it gets overwritten. Pass the
id in iopt_remove_access() for a proper cleanup.

The existing callers should just pass in access->iopt_access_list_id.

Link: https://lore.kernel.org/r/7bb939b9e0102da0c099572bb3de78ab7622221e.1690523699.git.nicolinc@nvidia.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-28 13:31:24 -03:00
Jason Gunthorpe
b7c822fa6b iommufd: Set end correctly when doing batch carry
Even though the test suite covers this it somehow became obscured that
this wasn't working.

The test iommufd_ioas.mock_domain.access_domain_destory would blow up
rarely.

end should be set to 1 because this just pushed an item, the carry, to the
pfns list.

Sometimes the test would blow up with:

  BUG: kernel NULL pointer dereference, address: 0000000000000000
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: 0000 [#1] SMP
  CPU: 5 PID: 584 Comm: iommufd Not tainted 6.5.0-rc1-dirty #1236
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
  RIP: 0010:batch_unpin+0xa2/0x100 [iommufd]
  Code: 17 48 81 fe ff ff 07 00 77 70 48 8b 15 b7 be 97 e2 48 85 d2 74 14 48 8b 14 fa 48 85 d2 74 0b 40 0f b6 f6 48 c1 e6 04 48 01 f2 <48> 8b 3a 48 c1 e0 06 89 ca 48 89 de 48 83 e7 f0 48 01 c7 e8 96 dc
  RSP: 0018:ffffc90001677a58 EFLAGS: 00010246
  RAX: 00007f7e2646f000 RBX: 0000000000000000 RCX: 0000000000000001
  RDX: 0000000000000000 RSI: 00000000fefc4c8d RDI: 0000000000fefc4c
  RBP: ffffc90001677a80 R08: 0000000000000048 R09: 0000000000000200
  R10: 0000000000030b98 R11: ffffffff81f3bb40 R12: 0000000000000001
  R13: ffff888101f75800 R14: ffffc90001677ad0 R15: 00000000000001fe
  FS:  00007f9323679740(0000) GS:ffff8881ba540000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 0000000105ede003 CR4: 00000000003706a0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   <TASK>
   ? show_regs+0x5c/0x70
   ? __die+0x1f/0x60
   ? page_fault_oops+0x15d/0x440
   ? lock_release+0xbc/0x240
   ? exc_page_fault+0x4a4/0x970
   ? asm_exc_page_fault+0x27/0x30
   ? batch_unpin+0xa2/0x100 [iommufd]
   ? batch_unpin+0xba/0x100 [iommufd]
   __iopt_area_unfill_domain+0x198/0x430 [iommufd]
   ? __mutex_lock+0x8c/0xb80
   ? __mutex_lock+0x6aa/0xb80
   ? xa_erase+0x28/0x30
   ? iopt_table_remove_domain+0x162/0x320 [iommufd]
   ? lock_release+0xbc/0x240
   iopt_area_unfill_domain+0xd/0x10 [iommufd]
   iopt_table_remove_domain+0x195/0x320 [iommufd]
   iommufd_hw_pagetable_destroy+0xb3/0x110 [iommufd]
   iommufd_object_destroy_user+0x8e/0xf0 [iommufd]
   iommufd_device_detach+0xc5/0x140 [iommufd]
   iommufd_selftest_destroy+0x1f/0x70 [iommufd]
   iommufd_object_destroy_user+0x8e/0xf0 [iommufd]
   iommufd_destroy+0x3a/0x50 [iommufd]
   iommufd_fops_ioctl+0xfb/0x170 [iommufd]
   __x64_sys_ioctl+0x40d/0x9a0
   do_syscall_64+0x3c/0x80
   entry_SYSCALL_64_after_hwframe+0x46/0xb0

Link: https://lore.kernel.org/r/3-v1-85aacb2af554+bc-iommufd_syz3_jgg@nvidia.com
Cc: <stable@vger.kernel.org>
Fixes: f394576eb1 ("iommufd: PFN handling for iopt_pages")
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Reported-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-27 11:27:20 -03:00
Jason Gunthorpe
99f98a7c0d iommufd: IOMMUFD_DESTROY should not increase the refcount
syzkaller found a race where IOMMUFD_DESTROY increments the refcount:

       obj = iommufd_get_object(ucmd->ictx, cmd->id, IOMMUFD_OBJ_ANY);
       if (IS_ERR(obj))
               return PTR_ERR(obj);
       iommufd_ref_to_users(obj);
       /* See iommufd_ref_to_users() */
       if (!iommufd_object_destroy_user(ucmd->ictx, obj))

As part of the sequence to join the two existing primitives together.

Allowing the refcount the be elevated without holding the destroy_rwsem
violates the assumption that all temporary refcount elevations are
protected by destroy_rwsem. Racing IOMMUFD_DESTROY with
iommufd_object_destroy_user() will cause spurious failures:

  WARNING: CPU: 0 PID: 3076 at drivers/iommu/iommufd/device.c:477 iommufd_access_destroy+0x18/0x20 drivers/iommu/iommufd/device.c:478
  Modules linked in:
  CPU: 0 PID: 3076 Comm: syz-executor.0 Not tainted 6.3.0-rc1-syzkaller #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
  RIP: 0010:iommufd_access_destroy+0x18/0x20 drivers/iommu/iommufd/device.c:477
  Code: e8 3d 4e 00 00 84 c0 74 01 c3 0f 0b c3 0f 1f 44 00 00 f3 0f 1e fa 48 89 fe 48 8b bf a8 00 00 00 e8 1d 4e 00 00 84 c0 74 01 c3 <0f> 0b c3 0f 1f 44 00 00 41 57 41 56 41 55 4c 8d ae d0 00 00 00 41
  RSP: 0018:ffffc90003067e08 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff888109ea0300 RCX: 0000000000000000
  RDX: 0000000000000001 RSI: 0000000000000000 RDI: 00000000ffffffff
  RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88810bbb3500
  R10: ffff88810bbb3e48 R11: 0000000000000000 R12: ffffc90003067e88
  R13: ffffc90003067ea8 R14: ffff888101249800 R15: 00000000fffffffe
  FS:  00007ff7254fe6c0(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000555557262da8 CR3: 000000010a6fd000 CR4: 0000000000350ef0
  Call Trace:
   <TASK>
   iommufd_test_create_access drivers/iommu/iommufd/selftest.c:596 [inline]
   iommufd_test+0x71c/0xcf0 drivers/iommu/iommufd/selftest.c:813
   iommufd_fops_ioctl+0x10f/0x1b0 drivers/iommu/iommufd/main.c:337
   vfs_ioctl fs/ioctl.c:51 [inline]
   __do_sys_ioctl fs/ioctl.c:870 [inline]
   __se_sys_ioctl fs/ioctl.c:856 [inline]
   __x64_sys_ioctl+0x84/0xc0 fs/ioctl.c:856
   do_syscall_x64 arch/x86/entry/common.c:50 [inline]
   do_syscall_64+0x38/0x80 arch/x86/entry/common.c:80
   entry_SYSCALL_64_after_hwframe+0x63/0xcd

The solution is to not increment the refcount on the IOMMUFD_DESTROY path
at all. Instead use the xa_lock to serialize everything. The refcount
check == 1 and xa_erase can be done under a single critical region. This
avoids the need for any refcount incrementing.

It has the downside that if userspace races destroy with other operations
it will get an EBUSY instead of waiting, but this is kind of racing is
already dangerous.

Fixes: 2ff4bed7fe ("iommufd: File descriptor, context, kconfig and makefiles")
Link: https://lore.kernel.org/r/2-v1-85aacb2af554+bc-iommufd_syz3_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reported-by: syzbot+7574ebfe589049630608@syzkaller.appspotmail.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-27 11:27:19 -03:00
Jason Gunthorpe
6583c865de iommufd/selftest: Add a selftest for IOMMU_HWPT_ALLOC
Test the basic flow.

Link: https://lore.kernel.org/r/19-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:20:41 -03:00
Jason Gunthorpe
7a467e02b3 iommufd/selftest: Return the real idev id from selftest mock_domain
Now that we actually call iommufd_device_bind() we can return the
idev_id from that function to userspace for use in other APIs.

Link: https://lore.kernel.org/r/18-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:20:36 -03:00
Jason Gunthorpe
7074d7bd67 iommufd: Add IOMMU_HWPT_ALLOC
This allows userspace to manually create HWPTs on IOAS's and then use
those HWPTs as inputs to iommufd_device_attach/replace().

Following series will extend this to allow creating iommu_domains with
driver specific parameters.

Link: https://lore.kernel.org/r/17-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:20:31 -03:00
Nicolin Chen
fa1ffdb9e2 iommufd/selftest: Test iommufd_device_replace()
Allow the selftest to call the function on the mock idev, add some tests
to exercise it.

Link: https://lore.kernel.org/r/16-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:20:26 -03:00
Jason Gunthorpe
83f7bc6fdf iommufd: Make destroy_rwsem use a lock class per object type
The selftest invokes things like replace under the object lock of its
idev which protects the idev in a similar way to a real user.
Unfortunately this triggers lockdep. A lock class per type will solve the
problem.

Link: https://lore.kernel.org/r/15-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:20:21 -03:00
Jason Gunthorpe
e88d4ec154 iommufd: Add iommufd_device_replace()
Replace allows all the devices in a group to move in one step to a new
HWPT. Further, the HWPT move is done without going through a blocking
domain so that the IOMMU driver can implement some level of
non-distruption to ongoing DMA if that has meaning for it (eg for future
special driver domains)

Replace uses a lot of the same logic as normal attach, except the actual
domain change over has different restrictions, and we are careful to
sequence things so that failure is going to leave everything the way it
was, and not get trapped in a blocking domain or something if there is
ENOMEM.

Link: https://lore.kernel.org/r/14-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:20:16 -03:00
Jason Gunthorpe
ea2d6124b5 iommufd: Reorganize iommufd_device_attach into iommufd_device_change_pt
The code flow for first time attaching a PT and replacing a PT is very
similar except for the lowest do_attach step.

Reorganize this so that the do_attach step is a function pointer.

Replace requires destroying the old HWPT once it is replaced. This
destruction cannot be done under all the locks that are held in the
function pointer, so the signature allows returning a HWPT which will be
destroyed by the caller after everything is unlocked.

Link: https://lore.kernel.org/r/12-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:20:06 -03:00
Jason Gunthorpe
31422dff18 iommufd: Fix locking around hwpt allocation
Due to the auto_domains mechanism the ioas->mutex must be held until
the hwpt is completely setup by iommufd_object_abort_and_destroy() or
iommufd_object_finalize().

This prevents a concurrent iommufd_device_auto_get_domain() from seeing
an incompletely initialized object through the ioas->hwpt_list.

To make this more consistent move the unlock until after finalize.

Fixes: e8d5721003 ("iommufd: Add kAPI toward external drivers for physical devices")
Link: https://lore.kernel.org/r/11-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:20:02 -03:00
Jason Gunthorpe
70eadc7fc7 iommufd: Allow a hwpt to be aborted after allocation
During creation the hwpt must have the ioas->mutex held until the object
is finalized. This means we need to be able to call
iommufd_object_abort_and_destroy() while holding the mutex.

Since iommufd_hw_pagetable_destroy() also needs the mutex this is
problematic.

Fix it by creating a special abort op for the object that can assume the
caller is holding the lock, as required by the contract.

The next patch will add another iommufd_object_abort_and_destroy() for a
hwpt.

Fixes: e8d5721003 ("iommufd: Add kAPI toward external drivers for physical devices")
Link: https://lore.kernel.org/r/10-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:19:57 -03:00
Jason Gunthorpe
17bad52708 iommufd: Add enforced_cache_coherency to iommufd_hw_pagetable_alloc()
Logically the HWPT should have the coherency set properly for the device
that it is being created for when it is created.

This was happening implicitly if the immediate_attach was set because
iommufd_hw_pagetable_attach() does it as the first thing.

Do it unconditionally so !immediate_attach works properly.

Link: https://lore.kernel.org/r/9-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:19:52 -03:00
Jason Gunthorpe
d03f1336fd iommufd: Move putting a hwpt to a helper function
Next patch will need to call this from two places.

Link: https://lore.kernel.org/r/8-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:19:47 -03:00
Jason Gunthorpe
1d149ab2e0 iommufd: Make sw_msi_start a group global
The sw_msi_start is only set by the ARM drivers and it is always constant.
Due to the way vfio/iommufd allow domains to be re-used between
devices we have a built in assumption that there is only one value
for sw_msi_start and it is global to the system.

To make replace simpler where we may not reparse the
iommu_get_resv_regions() move the sw_msi_start to the iommufd_group so it
is always available once any HWPT has been attached.

Link: https://lore.kernel.org/r/7-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:19:42 -03:00
Jason Gunthorpe
269c5238c5 iommufd: Use the iommufd_group to avoid duplicate MSI setup
This only needs to be done once per group, not once per device. The once
per device was a way to make the device list work. Since we are abandoning
this we can optimize things a bit.

Link: https://lore.kernel.org/r/6-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:19:37 -03:00
Jason Gunthorpe
34f327a985 iommufd: Keep track of each device's reserved regions instead of groups
The driver facing API in the iommu core makes the reserved regions
per-device. An algorithm in the core code consolidates the regions of all
the devices in a group to return the group view.

To allow for devices to be hotplugged into the group iommufd would re-load
the entire group's reserved regions for each device, just in case they
changed.

Further iommufd already has to deal with duplicated/overlapping reserved
regions as it must union all the groups together.

Thus simplify all of this to just use the device reserved regions
interface directly from the iommu driver.

Link: https://lore.kernel.org/r/5-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Suggested-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:19:32 -03:00
Jason Gunthorpe
91a2e17e24 iommufd: Replace the hwpt->devices list with iommufd_group
The devices list was used as a simple way to avoid having per-group
information. Now that this seems to be unavoidable, just commit to
per-group information fully and remove the devices list from the HWPT.

The iommufd_group stores the currently assigned HWPT for the entire group
and we can manage the per-device attach/detach with a list in the
iommufd_group.

For destruction the flow is organized to make the following patches
easier, the actual call to iommufd_object_destroy_user() is done at the
top of the call chain without holding any locks. The HWPT to be destroyed
is returned out from the locked region to make this possible. Later
patches create locking that requires this.

Link: https://lore.kernel.org/r/3-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:19:22 -03:00
Jason Gunthorpe
3a3329a7f1 iommufd: Add iommufd_group
When the hwpt to device attachment is fairly static we could get away with
the simple approach of keeping track of the groups via a device list. But
with replace this is infeasible.

Add an automatically managed struct that is 1:1 with the iommu_group
per-ictx so we can store the necessary tracking information there.

Link: https://lore.kernel.org/r/2-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:19:17 -03:00
Jason Gunthorpe
d525a5b8cf iommufd: Move isolated msi enforcement to iommufd_device_bind()
With the recent rework this no longer needs to be done at domain
attachment time, we know if the device is usable by iommufd when we bind
it.

The value of msi_device_has_isolated_msi() is not allowed to change while
a driver is bound.

Link: https://lore.kernel.org/r/1-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-07-26 10:16:43 -03:00
Yi Liu
c1cce6d079 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>
2023-07-25 10:20:50 -06:00
Yi Liu
1c9dc07487 iommufd: Add iommufd_ctx_from_fd()
It's common to get a reference to the iommufd context from a given file
descriptor. So adds an API for it. Existing users of this API are compiled
only when IOMMUFD is enabled, so no need to have a stub for the IOMMUFD
disabled case.

Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-21-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:19:53 -06:00
Nicolin Chen
e23a6217f3 iommufd/device: Add iommufd_access_detach() API
Previously, the detach routine is only done by the destroy(). And it was
called by vfio_iommufd_emulated_unbind() when the device runs close(), so
all the mappings in iopt were cleaned in that setup, when the call trace
reaches this detach() routine.

Now, there's a need of a detach uAPI, meaning that it does not only need
a new iommufd_access_detach() API, but also requires access->ops->unmap()
call as a cleanup. So add one.

However, leaving that unprotected can introduce some potential of a race
condition during the pin_/unpin_pages() call, where access->ioas->iopt is
getting referenced. So, add an ioas_lock to protect the context of iopt
referencings.

Also, to allow the iommufd_access_unpin_pages() callback to happen via
this unmap() call, add an ioas_unpin pointer, so the unpin routine won't
be affected by the "access->ioas = NULL" trick.

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: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-15-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:19:14 -06:00
Yi Liu
78d3df457a iommufd: Add helper to retrieve iommufd_ctx and devid
This is needed by the vfio-pci driver to report affected devices in the
hot-reset for a given device.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.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/20230718105542.4138-6-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:17:55 -06:00
Yi Liu
86b0a96c29 iommufd: Add iommufd_ctx_has_group()
This adds the helper to check if any device within the given iommu_group
has been bound with the iommufd_ctx. This is helpful for the checking on
device ownership for the devices which have not been bound but cannot be
bound to any other iommufd_ctx as the iommu_group has been bound.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.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/20230718105542.4138-5-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:17:52 -06:00
Yi Liu
eda175dfe2 iommufd: Reserve all negative IDs in the iommufd xarray
With this reservation, IOMMUFD users can encode the negative IDs for
specific purposes. e.g. VFIO needs two reserved values to tell userspace
the ID returned is not valid but has other meaning.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.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/20230718105542.4138-4-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-07-25 10:17:48 -06:00
Linus Torvalds
31929ae008 iommufd for 6.5
Just two RC syzkaller fixes, both for the same basic issue, using the area
 pointer during an access forced unmap while the locks protecting it were
 let go.
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Merge tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd

Pull iommufd updates from Jason Gunthorpe:
 "Just two syzkaller fixes, both for the same basic issue: using the
  area pointer during an access forced unmap while the locks protecting
  it were let go"

* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd:
  iommufd: Call iopt_area_contig_done() under the lock
  iommufd: Do not access the area pointer after unlocking
2023-06-29 20:57:27 -07:00
Jason Gunthorpe
dbe245cdf5 iommufd: Call iopt_area_contig_done() under the lock
The iter internally holds a pointer to the area and
iopt_area_contig_done() will dereference it. The pointer is not valid
outside the iova_rwsem.

syzkaller reports:

  BUG: KASAN: slab-use-after-free in iommufd_access_unpin_pages+0x363/0x370
  Read of size 8 at addr ffff888022286e20 by task syz-executor669/5771

  CPU: 0 PID: 5771 Comm: syz-executor669 Not tainted 6.4.0-rc5-syzkaller-00313-g4c605260bc60 #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
  Call Trace:
   <TASK>
   dump_stack_lvl+0xd9/0x150
   print_address_description.constprop.0+0x2c/0x3c0
   kasan_report+0x11c/0x130
   iommufd_access_unpin_pages+0x363/0x370
   iommufd_test_access_unmap+0x24b/0x390
   iommufd_access_notify_unmap+0x24c/0x3a0
   iopt_unmap_iova_range+0x4c4/0x5f0
   iopt_unmap_all+0x27/0x50
   iommufd_ioas_unmap+0x3d0/0x490
   iommufd_fops_ioctl+0x317/0x4b0
   __x64_sys_ioctl+0x197/0x210
   do_syscall_64+0x39/0xb0
   entry_SYSCALL_64_after_hwframe+0x63/0xcd
  RIP: 0033:0x7fec1dae3b19
  Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007fec1da74308 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  RAX: ffffffffffffffda RBX: 00007fec1db6b438 RCX: 00007fec1dae3b19
  RDX: 0000000020000100 RSI: 0000000000003b86 RDI: 0000000000000003
  RBP: 00007fec1db6b430 R08: 00007fec1da74700 R09: 0000000000000000
  R10: 00007fec1da74700 R11: 0000000000000246 R12: 00007fec1db6b43c
  R13: 00007fec1db39074 R14: 6d6f692f7665642f R15: 0000000000022000
   </TASK>

  Allocated by task 5770:
   kasan_save_stack+0x22/0x40
   kasan_set_track+0x25/0x30
   __kasan_kmalloc+0xa2/0xb0
   iopt_alloc_area_pages+0x94/0x560
   iopt_map_user_pages+0x205/0x4e0
   iommufd_ioas_map+0x329/0x5f0
   iommufd_fops_ioctl+0x317/0x4b0
   __x64_sys_ioctl+0x197/0x210
   do_syscall_64+0x39/0xb0
   entry_SYSCALL_64_after_hwframe+0x63/0xcd

  Freed by task 5770:
   kasan_save_stack+0x22/0x40
   kasan_set_track+0x25/0x30
   kasan_save_free_info+0x2e/0x40
   ____kasan_slab_free+0x160/0x1c0
   slab_free_freelist_hook+0x8b/0x1c0
   __kmem_cache_free+0xaf/0x2d0
   iopt_unmap_iova_range+0x288/0x5f0
   iopt_unmap_all+0x27/0x50
   iommufd_ioas_unmap+0x3d0/0x490
   iommufd_fops_ioctl+0x317/0x4b0
   __x64_sys_ioctl+0x197/0x210
   do_syscall_64+0x39/0xb0
   entry_SYSCALL_64_after_hwframe+0x63/0xcd

The parallel unmap free'd iter->area the instant the lock was released.

Fixes: 51fe6141f0 ("iommufd: Data structure to provide IOVA to PFN mapping")
Link: https://lore.kernel.org/r/2-v2-9a03761d445d+54-iommufd_syz2_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reported-by: syzbot+6c8d756f238a75fc3eb8@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/r/000000000000905eba05fe38e9f2@google.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-06-26 09:00:23 -03:00
Jason Gunthorpe
804ca14d04 iommufd: Do not access the area pointer after unlocking
A concurrent unmap can trigger freeing of the area pointers while we are
generating an unmapping notification for accesses.

syzkaller reports:

  BUG: KASAN: slab-use-after-free in iopt_unmap_iova_range+0x5ba/0x5f0
  Read of size 4 at addr ffff888075996184 by task syz-executor.2/31160

  CPU: 1 PID: 31160 Comm: syz-executor.2 Not tainted 6.4.0-rc5-syzkaller-00313-g4c605260bc60 #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
  Call Trace:
   <TASK>
   dump_stack_lvl+0xd9/0x150
   print_address_description.constprop.0+0x2c/0x3c0
   kasan_report+0x11c/0x130
   iopt_unmap_iova_range+0x5ba/0x5f0
   iopt_unmap_all+0x27/0x50
   iommufd_ioas_unmap+0x3d0/0x490
   iommufd_fops_ioctl+0x317/0x4b0
   __x64_sys_ioctl+0x197/0x210
   do_syscall_64+0x39/0xb0
   entry_SYSCALL_64_after_hwframe+0x63/0xcd
  RIP: 0033:0x7f0812c8c169
  Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
  RSP: 002b:00007f0813914168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  RAX: ffffffffffffffda RBX: 00007f0812dabf80 RCX: 00007f0812c8c169
  RDX: 0000000020000100 RSI: 0000000000003b86 RDI: 0000000000000005
  RBP: 00007f0812ce7ca1 R08: 0000000000000000 R09: 0000000000000000
  R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
  R13: 00007f0812ecfb1f R14: 00007f0813914300 R15: 0000000000022000
   </TASK>

  Allocated by task 31160:
   kasan_save_stack+0x22/0x40
   kasan_set_track+0x25/0x30
   __kasan_kmalloc+0xa2/0xb0
   iopt_alloc_area_pages+0x94/0x560
   iopt_map_user_pages+0x205/0x4e0
   iommufd_ioas_map+0x329/0x5f0
   iommufd_fops_ioctl+0x317/0x4b0
   __x64_sys_ioctl+0x197/0x210
   do_syscall_64+0x39/0xb0
   entry_SYSCALL_64_after_hwframe+0x63/0xcd

  Freed by task 31161:
   kasan_save_stack+0x22/0x40
   kasan_set_track+0x25/0x30
   kasan_save_free_info+0x2e/0x40
   ____kasan_slab_free+0x160/0x1c0
   slab_free_freelist_hook+0x8b/0x1c0
   __kmem_cache_free+0xaf/0x2d0
   iopt_unmap_iova_range+0x288/0x5f0
   iopt_unmap_all+0x27/0x50
   iommufd_ioas_unmap+0x3d0/0x490
   iommufd_fops_ioctl+0x317/0x4b0
   __x64_sys_ioctl+0x197/0x210
   do_syscall_64+0x39/0xb0
   entry_SYSCALL_64_after_hwframe+0x63/0xcd

  The buggy address belongs to the object at ffff888075996100
   which belongs to the cache kmalloc-cg-192 of size 192
  The buggy address is located 132 bytes inside of
   freed 192-byte region [ffff888075996100, ffff8880759961c0)

  The buggy address belongs to the physical page:
  page:ffffea0001d66580 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x75996
  memcg:ffff88801f1c2701
  flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
  page_type: 0xffffffff()
  raw: 00fff00000000200 ffff88801244ddc0 dead000000000122 0000000000000000
  raw: 0000000000000000 0000000080100010 00000001ffffffff ffff88801f1c2701
  page dumped because: kasan: bad access detected
  page_owner tracks the page as allocated
  page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 31157, tgid 31154 (syz-executor.0), ts 1984547323469, free_ts 1983933451331
   post_alloc_hook+0x2db/0x350
   get_page_from_freelist+0xf41/0x2c00
   __alloc_pages+0x1cb/0x4a0
   alloc_pages+0x1aa/0x270
   allocate_slab+0x25f/0x390
   ___slab_alloc+0xa91/0x1400
   __slab_alloc.constprop.0+0x56/0xa0
   __kmem_cache_alloc_node+0x136/0x320
   kmalloc_trace+0x26/0xe0
   iommufd_test+0x1328/0x2c20
   iommufd_fops_ioctl+0x317/0x4b0
   __x64_sys_ioctl+0x197/0x210
   do_syscall_64+0x39/0xb0
   entry_SYSCALL_64_after_hwframe+0x63/0xcd
  page last free stack trace:
   free_unref_page_prepare+0x62e/0xcb0
   free_unref_page_list+0xe3/0xa70
   release_pages+0xcd8/0x1380
   tlb_batch_pages_flush+0xa8/0x1a0
   tlb_finish_mmu+0x14b/0x7e0
   exit_mmap+0x2b2/0x930
   __mmput+0x128/0x4c0
   mmput+0x60/0x70
   do_exit+0x9b0/0x29b0
   do_group_exit+0xd4/0x2a0
   get_signal+0x2318/0x25b0
   arch_do_signal_or_restart+0x79/0x5c0
   exit_to_user_mode_prepare+0x11f/0x240
   syscall_exit_to_user_mode+0x1d/0x50
   do_syscall_64+0x46/0xb0
   entry_SYSCALL_64_after_hwframe+0x63/0xcd

Precompute what is needed to call the access function and do not check the
area's num_accesses again as the pointer may not be valid anymore. Use a
counter instead.

Fixes: 51fe6141f0 ("iommufd: Data structure to provide IOVA to PFN mapping")
Link: https://lore.kernel.org/r/1-v2-9a03761d445d+54-iommufd_syz2_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reported-by: syzbot+1ad12d16afca0e7d2dde@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/r/0000000000001d40fc05fe385332@google.com
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-06-26 09:00:23 -03:00
Lorenzo Stoakes
0b295316b3 mm/gup: remove unused vmas parameter from pin_user_pages_remote()
No invocation of pin_user_pages_remote() uses the vmas parameter, so
remove it.  This forms part of a larger patch set eliminating the use of
the vmas parameters altogether.

Link: https://lkml.kernel.org/r/28f000beb81e45bf538a2aaa77c90f5482b67a32.1684350871.git.lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:25 -07:00
Jason Gunthorpe
692d42d411 Merge branch 'iommufd/for-rc' into for-next
The following selftest patch requires both the bug fixes and the
improvements of the selftest framework.

* iommufd/for-rc:
  iommufd: Do not corrupt the pfn list when doing batch carry
  iommufd: Fix unpinning of pages when an access is present
  iommufd: Check for uptr overflow
  Linux 6.3-rc5

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-04-04 11:04:30 -03:00
Tom Rix
c52159b5be iommufd/selftest: Set varaiable mock_iommu_device storage-class-specifier to static
smatch reports:

drivers/iommu/iommufd/selftest.c:295:21: warning: symbol
  'mock_iommu_device' was not declared. Should it be static?

This variable is only used in one file so it should be static.

Fixes: 65c619ae06 ("iommufd/selftest: Make selftest create a more complete mock device")
Link: https://lore.kernel.org/r/20230404002317.1912530-1-trix@redhat.com
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-04-04 11:02:39 -03:00
Jason Gunthorpe
13a0d1ae7e iommufd: Do not corrupt the pfn list when doing batch carry
If batch->end is 0 then setting npfns[0] before computing the new value of
pfns will fail to adjust the pfn and result in various page accounting
corruptions. It should be ordered after.

This seems to result in various kinds of page meta-data corruption related
failures:

  WARNING: CPU: 1 PID: 527 at mm/gup.c:75 try_grab_folio+0x503/0x740
  Modules linked in:
  CPU: 1 PID: 527 Comm: repro Not tainted 6.3.0-rc2-eeac8ede1755+ #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
  RIP: 0010:try_grab_folio+0x503/0x740
  Code: e3 01 48 89 de e8 6d c1 dd ff 48 85 db 0f 84 7c fe ff ff e8 4f bf dd ff 49 8d 47 ff 48 89 45 d0 e9 73 fe ff ff e8 3d bf dd ff <0f> 0b 31 db e9 d0 fc ff ff e8 2f bf dd ff 48 8b 5d c8 31 ff 48 89
  RSP: 0018:ffffc90000f37908 EFLAGS: 00010046
  RAX: 0000000000000000 RBX: 00000000fffffc02 RCX: ffffffff81504c26
  RDX: 0000000000000000 RSI: ffff88800d030000 RDI: 0000000000000002
  RBP: ffffc90000f37948 R08: 000000000003ca24 R09: 0000000000000008
  R10: 000000000003ca00 R11: 0000000000000023 R12: ffffea000035d540
  R13: 0000000000000001 R14: 0000000000000000 R15: ffffea000035d540
  FS:  00007fecbf659740(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000200011c3 CR3: 000000000ef66006 CR4: 0000000000770ee0
  PKRU: 55555554
  Call Trace:
   <TASK>
   internal_get_user_pages_fast+0xd32/0x2200
   pin_user_pages_fast+0x65/0x90
   pfn_reader_user_pin+0x376/0x390
   pfn_reader_next+0x14a/0x7b0
   pfn_reader_first+0x140/0x1b0
   iopt_area_fill_domain+0x74/0x210
   iopt_table_add_domain+0x30e/0x6e0
   iommufd_device_selftest_attach+0x7f/0x140
   iommufd_test+0x10ff/0x16f0
   iommufd_fops_ioctl+0x206/0x330
   __x64_sys_ioctl+0x10e/0x160
   do_syscall_64+0x3b/0x90
   entry_SYSCALL_64_after_hwframe+0x72/0xdc

Cc: <stable@vger.kernel.org>
Fixes: f394576eb1 ("iommufd: PFN handling for iopt_pages")
Link: https://lore.kernel.org/r/3-v1-ceab6a4d7d7a+94-iommufd_syz_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-04-04 09:10:55 -03:00
Jason Gunthorpe
727c28c1ce iommufd: Fix unpinning of pages when an access is present
syzkaller found that the calculation of batch_last_index should use
'start_index' since at input to this function the batch is either empty or
it has already been adjusted to cross any accesses so it will start at the
point we are unmapping from.

Getting this wrong causes the unmap to run over the end of the pages
which corrupts pages that were never mapped. In most cases this triggers
the num pinned debugging:

  WARNING: CPU: 0 PID: 557 at drivers/iommu/iommufd/pages.c:294 __iopt_area_unfill_domain+0x152/0x560
  Modules linked in:
  CPU: 0 PID: 557 Comm: repro Not tainted 6.3.0-rc2-eeac8ede1755 #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
  RIP: 0010:__iopt_area_unfill_domain+0x152/0x560
  Code: d2 0f ff 44 8b 64 24 54 48 8b 44 24 48 31 ff 44 89 e6 48 89 44 24 38 e8 fc d3 0f ff 45 85 e4 0f 85 eb 01 00 00 e8 0e d2 0f ff <0f> 0b e8 07 d2 0f ff 48 8b 44 24 38 89 5c 24 58 89 18 8b 44 24 54
  RSP: 0018:ffffc9000108baf0 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffffffff821e3f85
  RDX: 0000000000000000 RSI: ffff88800faf0000 RDI: 0000000000000002
  RBP: ffffc9000108bd18 R08: 000000000003ca25 R09: 0000000000000014
  R10: 000000000003ca00 R11: 0000000000000024 R12: 0000000000000004
  R13: 0000000000000801 R14: 00000000000007ff R15: 0000000000000800
  FS:  00007f3499ce1740(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000020000243 CR3: 00000000179c2001 CR4: 0000000000770ef0
  PKRU: 55555554
  Call Trace:
   <TASK>
   iopt_area_unfill_domain+0x32/0x40
   iopt_table_remove_domain+0x23f/0x4c0
   iommufd_device_selftest_detach+0x3a/0x90
   iommufd_selftest_destroy+0x55/0x70
   iommufd_object_destroy_user+0xce/0x130
   iommufd_destroy+0xa2/0xc0
   iommufd_fops_ioctl+0x206/0x330
   __x64_sys_ioctl+0x10e/0x160
   do_syscall_64+0x3b/0x90
   entry_SYSCALL_64_after_hwframe+0x72/0xdc

Also add some useful WARN_ON sanity checks.

Cc: <stable@vger.kernel.org>
Fixes: 8d160cd4d5 ("iommufd: Algorithms for PFN storage")
Link: https://lore.kernel.org/r/2-v1-ceab6a4d7d7a+94-iommufd_syz_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-04-04 09:10:55 -03:00