Commit Graph

141 Commits

Author SHA1 Message Date
Jason Gunthorpe
8541323285 iommufd: Add missing IOMMUFD_DRIVER kconfig for the selftest
Some kconfigs don't automatically include this symbol which results in sub
functions for some of the dirty tracking related things that are
non-functional. Thus the test suite will fail. select IOMMUFD_DRIVER in
the IOMMUFD_TEST kconfig to fix it.

Fixes: a9af47e382 ("iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP")
Link: https://lore.kernel.org/r/20240327182050.GA1363414@ziepe.ca
Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-04-14 13:52:08 -03:00
Jason Gunthorpe
bb04d13353 iommufd/selftest: Don't check map/unmap pairing with HUGE_PAGES
Since MOCK_HUGE_PAGE_SIZE was introduced it allows the core code to invoke
mock with large page sizes. This confuses the validation logic that checks
that map/unmap are paired.

This is because the page size computed for map is based on the physical
address and in many cases will always be the base page size, however the
entire range generated by iommufd will be passed to map.

Randomly iommufd can see small groups of physically contiguous pages,
(say 8k unaligned and grouped together), but that group crosses a huge
page boundary. The map side will observe this as a contiguous run and mark
it accordingly, but there is a chance the unmap side will end up
terminating interior huge pages in the middle of that group and trigger a
validation failure. Meaning the validation only works if the core code
passes the iova/length directly from iommufd to mock.

syzkaller randomly hits this with failures like:

  WARNING: CPU: 0 PID: 11568 at drivers/iommu/iommufd/selftest.c:461 mock_domain_unmap_pages+0x1c0/0x250
  Modules linked in:
  CPU: 0 PID: 11568 Comm: syz-executor.0 Not tainted 6.8.0-rc3+ #4
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
  RIP: 0010:mock_domain_unmap_pages+0x1c0/0x250
  Code: 2b e8 94 37 0f ff 48 d1 eb 31 ff 48 b8 00 00 00 00 00 00 20 00 48 21 c3 48 89 de e8 aa 32 0f ff 48 85 db 75 07 e8 70 37 0f ff <0f> 0b e8 69 37 0f ff 31 f6 31 ff e8 90 32 0f ff e8 5b 37 0f ff 4c
  RSP: 0018:ffff88800e707490 EFLAGS: 00010293
  RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff822dfae6
  RDX: ffff88800cf86400 RSI: ffffffff822dfaf0 RDI: 0000000000000007
  RBP: ffff88800e7074d8 R08: 0000000000000000 R09: ffffed1001167c90
  R10: 0000000000000000 R11: 0000000000000000 R12: 0000000001500000
  R13: 0000000000083000 R14: 0000000000000001 R15: 0000000000000800
  FS:  0000555556048480(0000) GS:ffff88806d400000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000001b2dc23000 CR3: 0000000008cbb000 CR4: 0000000000350eb0
  Call Trace:
   <TASK>
   __iommu_unmap+0x281/0x520
   iommu_unmap+0xc9/0x180
   iopt_area_unmap_domain_range+0x1b1/0x290
   iopt_area_unpin_domain+0x590/0x800
   __iopt_area_unfill_domain+0x22e/0x650
   iopt_area_unfill_domain+0x47/0x60
   iopt_unfill_domain+0x187/0x590
   iopt_table_remove_domain+0x267/0x2d0
   iommufd_hwpt_paging_destroy+0x1f1/0x370
   iommufd_object_remove+0x2a3/0x490
   iommufd_device_detach+0x23a/0x2c0
   iommufd_selftest_destroy+0x7a/0xf0
   iommufd_fops_release+0x1d3/0x340
   __fput+0x272/0xb50
   __fput_sync+0x4b/0x60
   __x64_sys_close+0x8b/0x110
   do_syscall_64+0x71/0x140
   entry_SYSCALL_64_after_hwframe+0x46/0x4e

Do the simple thing and just disable the validation when the huge page
tests are being run.

Fixes: 7db521e23f ("iommufd/selftest: Hugepage mock domain support")
Link: https://lore.kernel.org/r/0-v1-1e17e60a5c8a+103fb-iommufd_mock_hugepg_jgg@nvidia.com
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-02-26 16:59:12 -04:00
Nicolin Chen
cf7c278982 iommufd: Fix protection fault in iommufd_test_syz_conv_iova
Syzkaller reported the following bug:

  general protection fault, probably for non-canonical address 0xdffffc0000000038: 0000 [#1] SMP KASAN
  KASAN: null-ptr-deref in range [0x00000000000001c0-0x00000000000001c7]
  Call Trace:
   lock_acquire
   lock_acquire+0x1ce/0x4f0
   down_read+0x93/0x4a0
   iommufd_test_syz_conv_iova+0x56/0x1f0
   iommufd_test_access_rw.isra.0+0x2ec/0x390
   iommufd_test+0x1058/0x1e30
   iommufd_fops_ioctl+0x381/0x510
   vfs_ioctl
   __do_sys_ioctl
   __se_sys_ioctl
   __x64_sys_ioctl+0x170/0x1e0
   do_syscall_x64
   do_syscall_64+0x71/0x140

This is because the new iommufd_access_change_ioas() sets access->ioas to
NULL during its process, so the lock might be gone in a concurrent racing
context.

Fix this by doing the same access->ioas sanity as iommufd_access_rw() and
iommufd_access_pin_pages() functions do.

Cc: stable@vger.kernel.org
Fixes: 9227da7816 ("iommufd: Add iommufd_access_change_ioas(_id) helpers")
Link: https://lore.kernel.org/r/3f1932acaf1dd494d404c04364d73ce8f57f3e5e.1708636627.git.nicolinc@nvidia.com
Reported-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-02-26 16:58:11 -04:00
Nicolin Chen
fde372df96 iommufd/selftest: Fix mock_dev_num bug
Syzkaller reported the following bug:
  sysfs: cannot create duplicate filename '/devices/iommufd_mock4'

  Call Trace:
    sysfs_warn_dup+0x71/0x90
    sysfs_create_dir_ns+0x1ee/0x260
    ? sysfs_create_mount_point+0x80/0x80
    ? spin_bug+0x1d0/0x1d0
    ? do_raw_spin_unlock+0x54/0x220
    kobject_add_internal+0x221/0x970
    kobject_add+0x11c/0x1e0
    ? lockdep_hardirqs_on_prepare+0x273/0x3e0
    ? kset_create_and_add+0x160/0x160
    ? kobject_put+0x5d/0x390
    ? bus_get_dev_root+0x4a/0x60
    ? kobject_put+0x5d/0x390
    device_add+0x1d5/0x1550
    ? __fw_devlink_link_to_consumers.isra.0+0x1f0/0x1f0
    ? __init_waitqueue_head+0xcb/0x150
    iommufd_test+0x462/0x3b60
    ? lock_release+0x1fe/0x640
    ? __might_fault+0x117/0x170
    ? reacquire_held_locks+0x4b0/0x4b0
    ? iommufd_selftest_destroy+0xd0/0xd0
    ? __might_fault+0xbe/0x170
    iommufd_fops_ioctl+0x256/0x350
    ? iommufd_option+0x180/0x180
    ? __lock_acquire+0x1755/0x45f0
    __x64_sys_ioctl+0xa13/0x1640

The bug is triggered when Syzkaller created multiple mock devices but
didn't destroy them in the same sequence, messing up the mock_dev_num
counter. Replace the atomic with an mock_dev_ida.

Cc: stable@vger.kernel.org
Fixes: 23a1b46f15 ("iommufd/selftest: Make the mock iommu driver into a real driver")
Link: https://lore.kernel.org/r/5af41d5af6d5c013cc51de01427abb8141b3587e.1708636627.git.nicolinc@nvidia.com
Reported-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-02-26 16:58:11 -04:00
Nicolin Chen
aeb004c0cd iommufd: Fix iopt_access_list_id overwrite bug
Syzkaller reported the following WARN_ON:
  WARNING: CPU: 1 PID: 4738 at drivers/iommu/iommufd/io_pagetable.c:1360

  Call Trace:
   iommufd_access_change_ioas+0x2fe/0x4e0
   iommufd_access_destroy_object+0x50/0xb0
   iommufd_object_remove+0x2a3/0x490
   iommufd_object_destroy_user
   iommufd_access_destroy+0x71/0xb0
   iommufd_test_staccess_release+0x89/0xd0
   __fput+0x272/0xb50
   __fput_sync+0x4b/0x60
   __do_sys_close
   __se_sys_close
   __x64_sys_close+0x8b/0x110
   do_syscall_x64

The mismatch between the access pointer in the list and the passed-in
pointer is resulting from an overwrite of access->iopt_access_list_id, in
iopt_add_access(). Called from iommufd_access_change_ioas() when
xa_alloc() succeeds but iopt_calculate_iova_alignment() fails.

Add a new_id in iopt_add_access() and only update iopt_access_list_id when
returning successfully.

Cc: stable@vger.kernel.org
Fixes: 9227da7816 ("iommufd: Add iommufd_access_change_ioas(_id) helpers")
Link: https://lore.kernel.org/r/2dda7acb25b8562ec5f1310de828ef5da9ef509c.1708636627.git.nicolinc@nvidia.com
Reported-by: Jason Gunthorpe <jgg@nvidia.com>
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-02-26 16:58:11 -04:00
Jason Gunthorpe
7adc0c1cfa iommufd: Reject non-zero data_type if no data_len is provided
Since the current design doesn't forward the data_type to the driver to
check unless there is a data_len/uptr for a driver specific struct we
should check and ensure that data_type is 0 if data_len is 0. Otherwise
any value is permitted.

Fixes: bd529dbb66 ("iommufd: Add a nested HW pagetable object")
Link: https://lore.kernel.org/r/0-v1-9b1ea6869554+110c60-iommufd_ck_data_type_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-02-21 09:25:02 -04:00
Joao Martins
4bbcbc6ea2 iommufd/iova_bitmap: Consider page offset for the pages to be pinned
For small bitmaps that aren't PAGE_SIZE aligned *and* that are less than
512 pages in bitmap length, use an extra page to be able to cover the
entire range e.g. [1M..3G] which would be iterated more efficiently in a
single iteration, rather than two.

Fixes: b058ea3ab5 ("vfio/iova_bitmap: refactor iova_bitmap_set() to better handle page boundaries")
Link: https://lore.kernel.org/r/20240202133415.23819-10-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Tested-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-02-06 11:31:46 -04:00
Joao Martins
7db521e23f iommufd/selftest: Hugepage mock domain support
Add support to mock iommu hugepages of 1M (for a 2K mock io page size). To
avoid breaking test suite defaults, the way this is done is by explicitly
creating a iommu mock device which has hugepage support (i.e. through
MOCK_FLAGS_DEVICE_HUGE_IOVA).

The same scheme is maintained of mock base page index tracking in the
XArray, except that an extra bit is added to mark it as a hugepage. One
subpage containing the dirty bit, means that the whole hugepage is dirty
(similar to AMD IOMMU non-standard page sizes). For clearing, same thing
applies, and it must clear all dirty subpages.

This is in preparation for dirty tracking to mark mock hugepages as
dirty to exercise all the iova-bitmap fixes.

Link: https://lore.kernel.org/r/20240202133415.23819-8-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-02-06 11:31:45 -04:00
Joao Martins
02a8c61a8b iommufd/selftest: Refactor mock_domain_read_and_clear_dirty()
Move the clearing of the dirty bit of the mock domain into
mock_domain_test_and_clear_dirty() helper, simplifying the caller
function.

Additionally, rework the mock_domain_read_and_clear_dirty() loop to
iterate over a potentially variable IO page size. No functional change
intended with the loop refactor.

This is in preparation for dirty tracking support for IOMMU hugepage mock
domains.

Link: https://lore.kernel.org/r/20240202133415.23819-7-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-02-06 11:31:45 -04:00
Joao Martins
2780025e01 iommufd/iova_bitmap: Handle recording beyond the mapped pages
IOVA bitmap is a zero-copy scheme of recording dirty bits that iterate the
different bitmap user pages at chunks of a maximum of
PAGE_SIZE/sizeof(struct page*) pages.

When the iterations are split up into 64G, the end of the range may be
broken up in a way that's aligned with a non base page PTE size. This
leads to only part of the huge page being recorded in the bitmap. Note
that in pratice this is only a problem for IOMMU dirty tracking i.e. when
the backing PTEs are in IOMMU hugepages and the bitmap is in base page
granularity. So far this not something that affects VF dirty trackers
(which reports and records at the same granularity).

To fix that, if there is a remainder of bits left to set in which the
current IOVA bitmap doesn't cover, make a copy of the bitmap structure and
iterate-and-set the rest of the bits remaining. Finally, when advancing
the iterator, skip all the bits that were set ahead.

Link: https://lore.kernel.org/r/20240202133415.23819-5-joao.m.martins@oracle.com
Reported-by: Avihai Horon <avihaih@nvidia.com>
Fixes: f35f22cc76 ("iommu/vt-d: Access/Dirty bit support for SS domains")
Fixes: 421a511a29 ("iommu/amd: Access/Dirty bit support in IOPTEs")
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Tested-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-02-06 11:31:45 -04:00
Joao Martins
d18411ec30 iommufd/iova_bitmap: Switch iova_bitmap::bitmap to an u8 array
iova_bitmap_mapped_length() don't deal correctly with the small bitmaps
(< 2M bitmaps) when the starting address isn't u64 aligned, leading to
skipping a tiny part of the IOVA range. This is materialized as not
marking data dirty that should otherwise have been.

Fix that by using a u8 * in the internal state of IOVA bitmap. Most of the
data structures use the type of the bitmap to adjust its indexes, thus
changing the type of the bitmap decreases the granularity of the bitmap
indexes.

Fixes: b058ea3ab5 ("vfio/iova_bitmap: refactor iova_bitmap_set() to better handle page boundaries")
Link: https://lore.kernel.org/r/20240202133415.23819-3-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Tested-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-02-06 11:31:45 -04:00
Joao Martins
a4ab7dedae iommufd/iova_bitmap: Bounds check mapped::pages access
Dirty IOMMU hugepages reported on a base page page-size granularity can
lead to an attempt to set dirty pages in the bitmap beyond the limits that
are pinned.

Bounds check the page index of the array we are trying to access is within
the limits before we kmap() and return otherwise.

While it is also a defensive check, this is also in preparation to defer
setting bits (outside the mapped range) to the next iteration(s) when the
pages become available.

Fixes: b058ea3ab5 ("vfio/iova_bitmap: refactor iova_bitmap_set() to better handle page boundaries")
Link: https://lore.kernel.org/r/20240202133415.23819-2-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Tested-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-02-06 11:31:45 -04:00
Linus Torvalds
86c4d58a99 iommufd for 6.8
This brings the first of three planned user IO page table invalidation
 operations:
 
  - IOMMU_HWPT_INVALIDATE allows invalidating the IOTLB integrated into the
    iommu itself. The Intel implementation will also generate an ATC
    invalidation to flush the device IOTLB as it unambiguously knows the
    device, but other HW will not.
 
 It goes along with the prior PR to implement userspace IO page tables (aka
 nested translation for VMs) to allow Intel to have full functionality for
 simple cases. An Intel implementation of the operation is provided.
 
 Fix a small bug in the selftest mock iommu driver probe.
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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:
 "This brings the first of three planned user IO page table invalidation
  operations:

   - IOMMU_HWPT_INVALIDATE allows invalidating the IOTLB integrated into
     the iommu itself. The Intel implementation will also generate an
     ATC invalidation to flush the device IOTLB as it unambiguously
     knows the device, but other HW will not.

  It goes along with the prior PR to implement userspace IO page tables
  (aka nested translation for VMs) to allow Intel to have full
  functionality for simple cases. An Intel implementation of the
  operation is provided.

  Also fix a small bug in the selftest mock iommu driver probe"

* tag 'for-linus-iommufd' of git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd:
  iommufd/selftest: Check the bus type during probe
  iommu/vt-d: Add iotlb flush for nested domain
  iommufd: Add data structure for Intel VT-d stage-1 cache invalidation
  iommufd/selftest: Add coverage for IOMMU_HWPT_INVALIDATE ioctl
  iommufd/selftest: Add IOMMU_TEST_OP_MD_CHECK_IOTLB test op
  iommufd/selftest: Add mock_domain_cache_invalidate_user support
  iommu: Add iommu_copy_struct_from_user_array helper
  iommufd: Add IOMMU_HWPT_INVALIDATE
  iommu: Add cache_invalidate_user op
2024-01-18 15:28:15 -08:00
Jason Gunthorpe
47f2bd2ff3 iommufd/selftest: Check the bus type during probe
This relied on the probe function only being invoked by the bus type mock
was registered on. The removal of the bus ops broke this assumption and
the probe could be called on non-mock bus types like PCI.

Check the bus type directly in probe.

Fixes: 17de3f5fdd ("iommu: Retire bus ops")
Link: https://lore.kernel.org/r/0-v1-82d59f7eab8c+40c-iommufd_mock_bus_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-01-11 15:53:28 -04:00
Nicolin Chen
e1fa6640d5 iommufd/selftest: Add IOMMU_TEST_OP_MD_CHECK_IOTLB test op
Allow to test whether IOTLB has been invalidated or not.

Link: https://lore.kernel.org/r/20240111041015.47920-6-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@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>
2024-01-11 13:01:25 -04:00
Nicolin Chen
ac8691203c iommufd/selftest: Add mock_domain_cache_invalidate_user support
Add mock_domain_cache_invalidate_user() data structure to support user
space selftest program to cover user cache invalidation pathway.

Link: https://lore.kernel.org/r/20240111041015.47920-5-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Co-developed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2024-01-11 13:01:25 -04:00
Yi Liu
8c6eabae38 iommufd: Add IOMMU_HWPT_INVALIDATE
In nested translation, the stage-1 page table is user-managed but cached
by the IOMMU hardware, so an update on present page table entries in the
stage-1 page table should be followed with a cache invalidation.

Add an IOMMU_HWPT_INVALIDATE ioctl to support such a cache invalidation.
It takes hwpt_id to specify the iommu_domain, and a multi-entry array to
support multiple invalidation data in one ioctl.

enum iommu_hwpt_invalidate_data_type is defined to tag the data type of
the entries in the multi-entry array.

Link: https://lore.kernel.org/r/20240111041015.47920-3-yi.l.liu@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>
2024-01-11 12:55:04 -04:00
Joerg Roedel
75f74f85a4 Merge branches 'apple/dart', 'arm/rockchip', 'arm/smmu', 'virtio', 'x86/vt-d', 'x86/amd' and 'core' into next 2024-01-03 09:59:32 +01:00
Jason Gunthorpe
6f9c4d8c46 iommufd: Do not UAF during iommufd_put_object()
The mixture of kernel and user space lifecycle objects continues to be
complicated inside iommufd. The obj->destroy_rwsem is used to bring order
to the kernel driver destruction sequence but it cannot be sequenced right
with the other refcounts so we end up possibly UAF'ing:

  BUG: KASAN: slab-use-after-free in __up_read+0x627/0x750 kernel/locking/rwsem.c:1342
  Read of size 8 at addr ffff888073cde868 by task syz-executor934/6535

  CPU: 1 PID: 6535 Comm: syz-executor934 Not tainted 6.6.0-rc7-syzkaller-00195-g2af9b20dbb39 #0
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
  Call Trace:
   <TASK>
   __dump_stack lib/dump_stack.c:88 [inline]
   dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
   print_address_description mm/kasan/report.c:364 [inline]
   print_report+0xc4/0x620 mm/kasan/report.c:475
   kasan_report+0xda/0x110 mm/kasan/report.c:588
   __up_read+0x627/0x750 kernel/locking/rwsem.c:1342
   iommufd_put_object drivers/iommu/iommufd/iommufd_private.h:149 [inline]
   iommufd_vfio_ioas+0x46c/0x580 drivers/iommu/iommufd/vfio_compat.c:146
   iommufd_fops_ioctl+0x347/0x4d0 drivers/iommu/iommufd/main.c:398
   vfs_ioctl fs/ioctl.c:51 [inline]
   __do_sys_ioctl fs/ioctl.c:871 [inline]
   __se_sys_ioctl fs/ioctl.c:857 [inline]
   __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857
   do_syscall_x64 arch/x86/entry/common.c:50 [inline]
   do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
   entry_SYSCALL_64_after_hwframe+0x63/0xcd

There are two races here, the more obvious one:

     CPU 0                                 CPU 1
 iommufd_put_object()
                                          iommufd_destroy()
  refcount_dec(&obj->users)

 	                                   iommufd_object_remove()
					   kfree()
  up_read(&obj->destroy_rwsem) // Boom

And there is also perhaps some possibility that the rwsem could hit an
issue:

     CPU 0                                 CPU 1
 iommufd_put_object()
                                         iommufd_object_destroy_user()
  refcount_dec(&obj->users);
 	                                  down_write(&obj->destroy_rwsem)
  up_read(&obj->destroy_rwsem);
                                             atomic_long_or(RWSEM_FLAG_WAITERS, &sem->count);
      tmp = atomic_long_add_return_release()
                                             rwsem_try_write_lock()
 	                                  iommufd_object_remove()
	                                  up_write(&obj->destroy_rwsem)
					  kfree()
      clear_nonspinnable() // Boom

Fix this by reorganizing this again so that two refcounts are used to keep
track of things with a rule that users == 0 && shortterm_users == 0 means
no other threads have that memory. Put a wait_queue in the iommufd_ctx
object that is triggered when any sub object reaches a 0
shortterm_users. This allows the same wait for userspace ioctls to finish
behavior that the rwsem was providing.

This is weaker still than the prior versions:

 - There is no bias on shortterm_users so if some thread is waiting to
   destroy other threads can continue to get new read sides

 - If destruction fails, eg because of an active in-kernel user, then
   shortterm_users will have cycled to zero momentarily blocking new users

 - If userspace races destroy with other userspace operations they
   continue to get an EBUSY since we still can't intermix looking up an ID
   and sleeping for its unref

In all cases these are things that userspace brings on itself, correct
programs will not hit them.

Fixes: 99f98a7c0d ("iommufd: IOMMUFD_DESTROY should not increase the refcount")
Link: https://lore.kernel.org/all/2-v2-ca9e00171c5b+123-iommufd_syz4_jgg@nvidia.com/
Reported-by: syzbot+d31adfb277377ef8fcba@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/r/00000000000055ef9a0609336580@google.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-11-29 20:30:03 -04:00
Jason Gunthorpe
bd7a282650 iommufd: Add iommufd_ctx to iommufd_put_object()
Will be used in the next patch.

Link: https://lore.kernel.org/r/1-v2-ca9e00171c5b+123-iommufd_syz4_jgg@nvidia.com/
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-11-29 20:30:03 -04:00
Robin Murphy
a9c362db39 iommu: Validate that devices match domains
Before we can allow drivers to coexist, we need to make sure that one
driver's domain ops can't misinterpret another driver's dev_iommu_priv
data. To that end, add a token to the domain so we can remember how it
was allocated - for now this may as well be the device ops, since they
still correlate 1:1 with drivers. We can trust ourselves for internal
default domain attachment, so add checks to cover all the public attach
interfaces.

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/097c6f30480e4efe12195d00ba0e84ea4837fb4c.1700589539.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2023-11-27 11:03:14 +01:00
Linus Torvalds
4bbdb725a3 IOMMU Updates for Linux v6.7
Including:
 
 	- Core changes:
 	  - Make default-domains mandatory for all IOMMU drivers
 	  - Remove group refcounting
 	  - Add generic_single_device_group() helper and consolidate
 	    drivers
 	  - Cleanup map/unmap ops
 	  - Scaling improvements for the IOVA rcache depot
 	  - Convert dart & iommufd to the new domain_alloc_paging()
 
 	- ARM-SMMU:
 	  - Device-tree binding update:
 	    - Add qcom,sm7150-smmu-v2 for Adreno on SM7150 SoC
 	  - SMMUv2:
 	    - Support for Qualcomm SDM670 (MDSS) and SM7150 SoCs
 	  - SMMUv3:
 	    - Large refactoring of the context descriptor code to
 	      move the CD table into the master, paving the way
 	      for '->set_dev_pasid()' support on non-SVA domains
 	  - Minor cleanups to the SVA code
 
 	- Intel VT-d:
 	  - Enable debugfs to dump domain attached to a pasid
 	  - Remove an unnecessary inline function.
 
 	- AMD IOMMU:
 	  - Initial patches for SVA support (not complete yet)
 
 	- S390 IOMMU:
 	  - DMA-API conversion and optimized IOTLB flushing
 
 	- Some smaller fixes and improvements
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Merge tag 'iommu-updates-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull iommu updates from Joerg Roedel:
 "Core changes:
   - Make default-domains mandatory for all IOMMU drivers
   - Remove group refcounting
   - Add generic_single_device_group() helper and consolidate drivers
   - Cleanup map/unmap ops
   - Scaling improvements for the IOVA rcache depot
   - Convert dart & iommufd to the new domain_alloc_paging()

  ARM-SMMU:
   - Device-tree binding update:
       - Add qcom,sm7150-smmu-v2 for Adreno on SM7150 SoC
   - SMMUv2:
       - Support for Qualcomm SDM670 (MDSS) and SM7150 SoCs
   - SMMUv3:
       - Large refactoring of the context descriptor code to move the CD
         table into the master, paving the way for '->set_dev_pasid()'
         support on non-SVA domains
   - Minor cleanups to the SVA code

  Intel VT-d:
   - Enable debugfs to dump domain attached to a pasid
   - Remove an unnecessary inline function

  AMD IOMMU:
   - Initial patches for SVA support (not complete yet)

  S390 IOMMU:
   - DMA-API conversion and optimized IOTLB flushing

  And some smaller fixes and improvements"

* tag 'iommu-updates-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (102 commits)
  iommu/dart: Remove the force_bypass variable
  iommu/dart: Call apple_dart_finalize_domain() as part of alloc_paging()
  iommu/dart: Convert to domain_alloc_paging()
  iommu/dart: Move the blocked domain support to a global static
  iommu/dart: Use static global identity domains
  iommufd: Convert to alloc_domain_paging()
  iommu/vt-d: Use ops->blocked_domain
  iommu/vt-d: Update the definition of the blocking domain
  iommu: Move IOMMU_DOMAIN_BLOCKED global statics to ops->blocked_domain
  Revert "iommu/vt-d: Remove unused function"
  iommu/amd: Remove DMA_FQ type from domain allocation path
  iommu: change iommu_map_sgtable to return signed values
  iommu/virtio: Add __counted_by for struct viommu_request and use struct_size()
  iommu/vt-d: debugfs: Support dumping a specified page table
  iommu/vt-d: debugfs: Create/remove debugfs file per {device, pasid}
  iommu/vt-d: debugfs: Dump entry pointing to huge page
  iommu/vt-d: Remove unused function
  iommu/arm-smmu-v3-sva: Remove bond refcount
  iommu/arm-smmu-v3-sva: Remove unused iommu_sva handle
  iommu/arm-smmu-v3: Rename cdcfg to cd_table
  ...
2023-11-09 13:37:28 -08:00
Jason Gunthorpe
b2b67c997b iommufd: Organize the mock domain alloc functions closer to Joerg's tree
Patches in Joerg's iommu tree to convert the mock driver to use
domain_alloc_paging() that clash badly with the way the selftest changes
for nesting were structured.

Massage the selftest so that it looks closer the code after the
domain_alloc_paging() conversion to ease the merge. Change
__mock_domain_alloc_paging() into mock_domain_alloc_paging() in the same
way as the iommu tree. The merge resolution then trivially takes both and
deletes mock_domain_alloc().

Link: https://lore.kernel.org/r/0-v1-90a855762c96+19de-mock_merge_jgg@nvidia.com
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-30 18:01:56 -03:00
Joao Martins
2e22aac3ea iommufd/selftest: Fix page-size check in iommufd_test_dirty()
iommufd_test_dirty()/IOMMU_TEST_OP_DIRTY sets the dirty bits in the mock
domain implementation that the userspace side validates against what it
obtains via the UAPI.

However in introducing iommufd_test_dirty() it forgot to validate page_size
being 0 leading to two possible divide-by-zero problems: one at the
beginning when calculating @max and while calculating the IOVA in the
XArray PFN tracking list.

While at it, validate the length to require non-zero value as well, as we
can't be allocating a 0-sized bitmap.

Link: https://lore.kernel.org/r/20231030113446.7056-1-joao.m.martins@oracle.com
Reported-by: syzbot+25dc7383c30ecdc83c38@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-iommu/00000000000005f6aa0608b9220f@google.com/
Fixes: a9af47e382 ("iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP")
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-30 12:03:20 -03:00
Jason Gunthorpe
361d744ddd iommufd: Add iopt_area_alloc()
We never initialize the two interval tree nodes, and zero fill is not the
same as RB_CLEAR_NODE. This can hide issues where we missed adding the
area to the trees. Factor out the allocation and clear the two nodes.

Fixes: 51fe6141f0 ("iommufd: Data structure to provide IOVA to PFN mapping")
Link: https://lore.kernel.org/r/20231030145035.GG691768@ziepe.ca
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-30 11:36:04 -03:00
Koichiro Den
e7250ab7ca iommufd: Fix missing update of domains_itree after splitting iopt_area
In iopt_area_split(), if the original iopt_area has filled a domain and is
linked to domains_itree, pages_nodes have to be properly
reinserted. Otherwise the domains_itree becomes corrupted and we will UAF.

Fixes: 51fe6141f0 ("iommufd: Data structure to provide IOVA to PFN mapping")
Link: https://lore.kernel.org/r/20231027162941.2864615-2-den@valinux.co.jp
Cc: stable@vger.kernel.org
Signed-off-by: Koichiro Den <den@valinux.co.jp>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-30 11:36:04 -03:00
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
Nicolin Chen
65fe32f7a4 iommufd/selftest: Add nested domain allocation for mock domain
Add nested domain support in the ->domain_alloc_user op with some proper
sanity checks. Then, add a domain_nested_ops for all nested domains and
split the get_md_pagetable helper into paging and nested helpers.

Also, add an iotlb as a testing property of a nested domain.

Link: https://lore.kernel.org/r/20231026043938.63898-10-yi.l.liu@intel.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:57 -03:00
Nicolin Chen
bd529dbb66 iommufd: Add a nested HW pagetable object
IOMMU_HWPT_ALLOC already supports iommu_domain allocation for usersapce.
But it can only allocate a hw_pagetable that associates to a given IOAS,
i.e. only a kernel-managed hw_pagetable of IOMMUFD_OBJ_HWPT_PAGING type.

IOMMU drivers can now support user-managed hw_pagetables, for two-stage
translation use cases that require user data input from the user space.

Add a new IOMMUFD_OBJ_HWPT_NESTED type with its abort/destroy(). Pair it
with a new iommufd_hwpt_nested structure and its to_hwpt_nested() helper.
Update the to_hwpt_paging() helper, so a NESTED-type hw_pagetable can be
handled in the callers, for example iommufd_hw_pagetable_enforce_rr().

Screen the inputs including the parent PAGING-type hw_pagetable that has
a need of a new nest_parent flag in the iommufd_hwpt_paging structure.

Extend the IOMMU_HWPT_ALLOC ioctl to accept an IOMMU driver specific data
input which is tagged by the enum iommu_hwpt_data_type. Also, update the
@pt_id to accept hwpt_id too besides an ioas_id. Then, use them to allocate
a hw_pagetable of IOMMUFD_OBJ_HWPT_NESTED type using the
iommufd_hw_pagetable_alloc_nested() allocator.

Link: https://lore.kernel.org/r/20231026043938.63898-8-yi.l.liu@intel.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Co-developed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:57 -03:00
Yi Liu
2bdabb8e82 iommu: Pass in parent domain with user_data to domain_alloc_user op
domain_alloc_user op already accepts user flags for domain allocation, add
a parent domain pointer and a driver specific user data support as well.
The user data would be tagged with a type for iommu drivers to add their
own driver specific user data per hw_pagetable.

Add a struct iommu_user_data as a bundle of data_ptr/data_len/type from an
iommufd core uAPI structure. Make the user data opaque to the core, since
a userspace driver must match the kernel driver. In the future, if drivers
share some common parameter, there would be a generic parameter as well.

Link: https://lore.kernel.org/r/20231026043938.63898-7-yi.l.liu@intel.com
Signed-off-by: Lu Baolu <baolu.lu@linux.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>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:57 -03:00
Nicolin Chen
b5021cb264 iommufd: Share iommufd_hwpt_alloc with IOMMUFD_OBJ_HWPT_NESTED
Allow iommufd_hwpt_alloc() to have a common routine but jump to different
allocators corresponding to different user input pt_obj types, either an
IOMMUFD_OBJ_IOAS for a PAGING hwpt or an IOMMUFD_OBJ_HWPT_PAGING as the
parent for a NESTED hwpt.

Also, move the "flags" validation to the hwpt allocator (paging), so that
later the hwpt_nested allocator can do its own separate flags validation.

Link: https://lore.kernel.org/r/20231026043938.63898-6-yi.l.liu@intel.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:57 -03:00
Nicolin Chen
89db31635c iommufd: Derive iommufd_hwpt_paging from iommufd_hw_pagetable
To prepare for IOMMUFD_OBJ_HWPT_NESTED, derive struct iommufd_hwpt_paging
from struct iommufd_hw_pagetable, by leaving the common members in struct
iommufd_hw_pagetable. Add a __iommufd_object_alloc and to_hwpt_paging()
helpers for the new structure.

Then, update "hwpt" to "hwpt_paging" throughout the files, accordingly.

Link: https://lore.kernel.org/r/20231026043938.63898-5-yi.l.liu@intel.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:56 -03:00
Jason Gunthorpe
58d84f430d iommufd/device: Wrap IOMMUFD_OBJ_HWPT_PAGING-only configurations
Some of the configurations during the attach/replace() should only apply
to IOMMUFD_OBJ_HWPT_PAGING. Once IOMMUFD_OBJ_HWPT_NESTED gets introduced
in a following patch, keeping them unconditionally in the common routine
will not work.

Wrap all of those PAGING-only configurations together into helpers. Do a
hwpt_is_paging check whenever calling them or their fallback routines.

Link: https://lore.kernel.org/r/20231026043938.63898-4-yi.l.liu@intel.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:56 -03:00
Jason Gunthorpe
9744a7ab62 iommufd: Rename IOMMUFD_OBJ_HW_PAGETABLE to IOMMUFD_OBJ_HWPT_PAGING
To add a new IOMMUFD_OBJ_HWPT_NESTED, rename the HWPT object to confine
it to PAGING hwpts/domains. The following patch will separate the hwpt
structure as well.

Link: https://lore.kernel.org/r/20231026043938.63898-3-yi.l.liu@intel.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:56 -03:00
Nicolin Chen
2ccabf81dd iommufd: Only enforce cache coherency in iommufd_hw_pagetable_alloc
According to the conversation in the following link:
https://lore.kernel.org/linux-iommu/20231020135501.GG3952@nvidia.com/

The enforce_cache_coherency should be set/enforced in the hwpt allocation
routine. The iommu driver in its attach_dev() op should decide whether to
reject or not a device that doesn't match with the configuration of cache
coherency. Drop the enforce_cache_coherency piece in the attach/replace()
and move the remaining "num_devices" piece closer to the refcount that is
using it.

Accordingly drop its function prototype in the header and mark it static.
Also add some extra comments to clarify the expected behaviors.

Link: https://lore.kernel.org/r/20231024012958.30842-1-nicolinc@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>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 12:56:37 -03:00
Joao Martins
0795b305da iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR flag
Change test_mock_dirty_bitmaps() to pass a flag where it specifies the flag
under test. The test does the same thing as the GET_DIRTY_BITMAP regular
test. Except that it tests whether the dirtied bits are fetched all the
same a second time, as opposed to observing them cleared.

Link: https://lore.kernel.org/r/20231024135109.73787-19-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:44 -03:00
Joao Martins
ae36fe70ce iommufd/selftest: Test out_capabilities in IOMMU_GET_HW_INFO
Enumerate the capabilities from the mock device and test whether it
advertises as expected. Include it as part of the iommufd_dirty_tracking
fixture.

Link: https://lore.kernel.org/r/20231024135109.73787-18-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:44 -03:00
Joao Martins
a9af47e382 iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP
Add a new test ioctl for simulating the dirty IOVAs in the mock domain, and
implement the mock iommu domain ops that get the dirty tracking supported.

The selftest exercises the usual main workflow of:

1) Setting dirty tracking from the iommu domain
2) Read and clear dirty IOPTEs

Different fixtures will test different IOVA range sizes, that exercise
corner cases of the bitmaps.

Link: https://lore.kernel.org/r/20231024135109.73787-17-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:44 -03:00
Joao Martins
7adf267d66 iommufd/selftest: Test IOMMU_HWPT_SET_DIRTY_TRACKING
Change mock_domain to supporting dirty tracking and add tests to exercise
the new SET_DIRTY_TRACKING API in the iommufd_dirty_tracking selftest
fixture.

Link: https://lore.kernel.org/r/20231024135109.73787-16-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:44 -03:00
Joao Martins
266ce58989 iommufd/selftest: Test IOMMU_HWPT_ALLOC_DIRTY_TRACKING
In order to selftest the iommu domain dirty enforcing implement the
mock_domain necessary support and add a new dev_flags to test that the
hwpt_alloc/attach_device fails as expected.

Expand the existing mock_domain fixture with a enforce_dirty test that
exercises the hwpt_alloc and device attachment.

Link: https://lore.kernel.org/r/20231024135109.73787-15-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:44 -03:00
Joao Martins
e04b23c8d4 iommufd/selftest: Expand mock_domain with dev_flags
Expand mock_domain test to be able to manipulate the device capabilities.
This allows testing with mockdev without dirty tracking support advertised
and thus make sure enforce_dirty test does the expected.

To avoid breaking IOMMUFD_TEST UABI replicate the mock_domain struct and
thus add an input dev_flags at the end.

Link: https://lore.kernel.org/r/20231024135109.73787-14-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:44 -03:00
Joao Martins
609848132c iommufd: Add a flag to skip clearing of IOPTE dirty
VFIO has an operation where it unmaps an IOVA while returning a bitmap with
the dirty data. In reality the operation doesn't quite query the IO
pagetables that the PTE was dirty or not. Instead it marks as dirty on
anything that was mapped, and doing so in one syscall.

In IOMMUFD the equivalent is done in two operations by querying with
GET_DIRTY_IOVA followed by UNMAP_IOVA. However, this would incur two TLB
flushes given that after clearing dirty bits IOMMU implementations require
invalidating their IOTLB, plus another invalidation needed for the UNMAP.
To allow dirty bits to be queried faster, add a flag
(IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR) that requests to not clear the dirty
bits from the PTE (but just reading them), under the expectation that the
next operation is the unmap. An alternative is to unmap and just
perpectually mark as dirty as that's the same behaviour as today. So here
equivalent functionally can be provided with unmap alone, and if real dirty
info is required it will amortize the cost while querying.

There's still a race against DMA where in theory the unmap of the IOVA
(when the guest invalidates the IOTLB via emulated iommu) would race
against the VF performing DMA on the same IOVA. As discussed in [0], we are
accepting to resolve this race as throwing away the DMA and it doesn't
matter if it hit physical DRAM or not, the VM can't tell if we threw it
away because the DMA was blocked or because we failed to copy the DRAM.

[0] https://lore.kernel.org/linux-iommu/20220502185239.GR8364@nvidia.com/

Link: https://lore.kernel.org/r/20231024135109.73787-10-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:43 -03:00
Joao Martins
7623683857 iommufd: Add capabilities to IOMMU_GET_HW_INFO
Extend IOMMUFD_CMD_GET_HW_INFO op to query generic iommu capabilities for a
given device.

Capabilities are IOMMU agnostic and use device_iommu_capable() API passing
one of the IOMMU_CAP_*. Enumerate IOMMU_CAP_DIRTY_TRACKING for now in the
out_capabilities field returned back to userspace.

Link: https://lore.kernel.org/r/20231024135109.73787-9-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:43 -03:00
Joao Martins
b9a60d6f85 iommufd: Add IOMMU_HWPT_GET_DIRTY_BITMAP
Connect a hw_pagetable to the IOMMU core dirty tracking
read_and_clear_dirty iommu domain op. It exposes all of the functionality
for the UAPI that read the dirtied IOVAs while clearing the Dirty bits from
the PTEs.

In doing so, add an IO pagetable API iopt_read_and_clear_dirty_data() that
performs the reading of dirty IOPTEs for a given IOVA range and then
copying back to userspace bitmap.

Underneath it uses the IOMMU domain kernel API which will read the dirty
bits, as well as atomically clearing the IOPTE dirty bit and flushing the
IOTLB at the end. The IOVA bitmaps usage takes care of the iteration of the
bitmaps user pages efficiently and without copies. Within the iterator
function we iterate over io-pagetable contigous areas that have been
mapped.

Contrary to past incantation of a similar interface in VFIO the IOVA range
to be scanned is tied in to the bitmap size, thus the application needs to
pass a appropriately sized bitmap address taking into account the iova
range being passed *and* page size ... as opposed to allowing bitmap-iova
!= iova.

Link: https://lore.kernel.org/r/20231024135109.73787-8-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:43 -03:00
Joao Martins
e2a4b29478 iommufd: Add IOMMU_HWPT_SET_DIRTY_TRACKING
Every IOMMU driver should be able to implement the needed iommu domain ops
to control dirty tracking.

Connect a hw_pagetable to the IOMMU core dirty tracking ops, specifically
the ability to enable/disable dirty tracking on an IOMMU domain
(hw_pagetable id). To that end add an io_pagetable kernel API to toggle
dirty tracking:

* iopt_set_dirty_tracking(iopt, [domain], state)

The intended caller of this is via the hw_pagetable object that is created.

Internally it will ensure the leftover dirty state is cleared /right
before/ dirty tracking starts. This is also useful for iommu drivers which
may decide that dirty tracking is always-enabled at boot without wanting to
toggle dynamically via corresponding iommu domain op.

Link: https://lore.kernel.org/r/20231024135109.73787-7-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:43 -03:00
Joao Martins
5f9bdbf4c6 iommufd: Add a flag to enforce dirty tracking on attach
Throughout IOMMU domain lifetime that wants to use dirty tracking, some
guarantees are needed such that any device attached to the iommu_domain
supports dirty tracking.

The idea is to handle a case where IOMMU in the system are assymetric
feature-wise and thus the capability may not be supported for all devices.
The enforcement is done by adding a flag into HWPT_ALLOC namely:

	IOMMU_HWPT_ALLOC_DIRTY_TRACKING

.. Passed in HWPT_ALLOC ioctl() flags. The enforcement is done by creating
a iommu_domain via domain_alloc_user() and validating the requested flags
with what the device IOMMU supports (and failing accordingly) advertised).
Advertising the new IOMMU domain feature flag requires that the individual
iommu driver capability is supported when a future device attachment
happens.

Link: https://lore.kernel.org/r/20231024135109.73787-6-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:42 -03:00
Joao Martins
13578d4ebe iommufd/iova_bitmap: Move symbols to IOMMUFD namespace
Have the IOVA bitmap exported symbols adhere to the IOMMUFD symbol
export convention i.e. using the IOMMUFD namespace. In doing so,
import the namespace in the current users. This means VFIO and the
vfio-pci drivers that use iova_bitmap_set().

Link: https://lore.kernel.org/r/20231024135109.73787-4-joao.m.martins@oracle.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:42 -03:00
Joao Martins
8c9c727b61 vfio: Move iova_bitmap into iommufd
Both VFIO and IOMMUFD will need iova bitmap for storing dirties and walking
the user bitmaps, so move to the common dependency into IOMMUFD.  In doing
so, create the symbol IOMMUFD_DRIVER which designates the builtin code that
will be used by drivers when selected. Today this means MLX5_VFIO_PCI and
PDS_VFIO_PCI. IOMMU drivers will do the same (in future patches) when
supporting dirty tracking and select IOMMUFD_DRIVER accordingly.

Given that the symbol maybe be disabled, add header definitions in
iova_bitmap.h for when IOMMUFD_DRIVER=n

Link: https://lore.kernel.org/r/20231024135109.73787-3-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:42 -03:00
Yi Liu
408663619f iommufd/selftest: Add domain_alloc_user() support in iommu mock
Add mock_domain_alloc_user() and a new test case for
IOMMU_HWPT_ALLOC_NEST_PARENT.

Link: https://lore.kernel.org/r/20230928071528.26258-6-yi.l.liu@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>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-10 13:31:24 -03:00
Yi Liu
4ff5421633 iommufd: Support allocating nested parent domain
Extend IOMMU_HWPT_ALLOC to allocate domains to be used as parent (stage-2)
in nested translation.

Add IOMMU_HWPT_ALLOC_NEST_PARENT to the uAPI.

Link: https://lore.kernel.org/r/20230928071528.26258-5-yi.l.liu@intel.com
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-10 13:31:24 -03:00