Commit Graph

79 Commits

Author SHA1 Message Date
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
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
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
9fdf791612 Merge branch 'vfio_mdev_ops' into iommufd.git for-next
Yi Liu says

===================
The .bind_iommufd op of vfio emulated devices are either empty or does
nothing. This is different with the vfio physical devices, to add vfio
device cdev, need to make them act the same.

This series first makes the .bind_iommufd op of vfio emulated devices to
create iommufd_access, this introduces a new iommufd API. Then let the
driver that does not provide .bind_iommufd op to use the vfio emulated
iommufd op set. This makes all vfio device drivers have consistent iommufd
operations, which is good for adding new device uAPIs in the device cdev
===================

* branch 'vfio_mdev_ops':
  vfio: Check the presence for iommufd callbacks in __vfio_register_dev()
  vfio/mdev: Uses the vfio emulated iommufd ops set in the mdev sample drivers
  vfio-iommufd: Make vfio_iommufd_emulated_bind() return iommufd_access ID
  vfio-iommufd: No need to record iommufd_ctx in vfio_device
  iommufd: Create access in vfio_iommufd_emulated_bind()
  iommu/iommufd: Pass iommufd_ctx pointer in iommufd_get_ioas()

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-03-31 13:43:57 -03:00
Yi Liu
632fda7f91 vfio-iommufd: Make vfio_iommufd_emulated_bind() return iommufd_access ID
vfio device cdev needs to return iommufd_access ID to userspace if
bind_iommufd succeeds.

Link: https://lore.kernel.org/r/20230327093351.44505-5-yi.l.liu@intel.com
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>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-03-31 13:43:32 -03:00
Nicolin Chen
54b47585db iommufd: Create access in vfio_iommufd_emulated_bind()
There are needs to created iommufd_access prior to have an IOAS and set
IOAS later. Like the vfio device cdev needs to have an iommufd object
to represent the bond (iommufd_access) and IOAS replacement.

Moves the iommufd_access_create() call into vfio_iommufd_emulated_bind(),
making it symmetric with the __vfio_iommufd_access_destroy() call in the
vfio_iommufd_emulated_unbind(). This means an access is created/destroyed
by the bind()/unbind(), and the vfio_iommufd_emulated_attach_ioas() only
updates the access->ioas pointer.

Since vfio_iommufd_emulated_bind() does not provide ioas_id, drop it from
the argument list of iommufd_access_create(). Instead, add a new access
API iommufd_access_attach() to set the access->ioas pointer. Also, set
vdev->iommufd_attached accordingly, similar to the physical pathway.

Link: https://lore.kernel.org/r/20230327093351.44505-3-yi.l.liu@intel.com
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>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-03-31 13:43:31 -03:00
Jason Gunthorpe
65c619ae06 iommufd/selftest: Make selftest create a more complete mock device
iommufd wants to use more infrastructure, like the iommu_group, that the
mock device does not support. Create a more complete mock device that can
go through the whole cycle of ownership, blocking domain, and has an
iommu_group.

This requires creating a real struct device on a real bus to be able to
connect it to a iommu_group. Unfortunately we cannot formally attach the
mock iommu driver as an actual driver as the iommu core does not allow
more than one driver or provide a general way for busses to link to
iommus. This can be solved with a little hack to open code the dev_iommus
struct.

With this infrastructure things work exactly the same as the normal domain
path, including the auto domains mechanism and direct attach of hwpts.  As
the created hwpt is now an autodomain it is no longer required to destroy
it and trying to do so will trigger a failure.

Link: https://lore.kernel.org/r/11-v3-ae9c2975a131+2e1e8-iommufd_hwpt_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-03-06 13:06:11 -04:00
Jason Gunthorpe
339fbf3ae1 iommufd: Make iommufd_hw_pagetable_alloc() do iopt_table_add_domain()
The HWPT is always linked to an IOAS and once a HWPT exists its domain
should be fully mapped. This ended up being split up into device.c during
a two phase creation that was a bit confusing.

Move the iopt_table_add_domain() into iommufd_hw_pagetable_alloc() by
having it call back to device.c to complete the domain attach in the
required order.

Calling iommufd_hw_pagetable_alloc() with immediate_attach = false will
work on most drivers, but notably the SMMU drivers will fail because they
can't decide what kind of domain to create until they are attached. This
will be fixed when the domain_alloc function can take in a struct device.

Link: https://lore.kernel.org/r/6-v3-ae9c2975a131+2e1e8-iommufd_hwpt_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-03-06 10:51:57 -04:00
Jason Gunthorpe
7e7ec8a569 iommufd: Move iommufd_device to iommufd_private.h
hw_pagetable.c will need this in the next patches.

Link: https://lore.kernel.org/r/5-v3-ae9c2975a131+2e1e8-iommufd_hwpt_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-03-06 10:51:57 -04:00
Jason Gunthorpe
25cde97d95 iommufd: Move ioas related HWPT destruction into iommufd_hw_pagetable_destroy()
A HWPT is permanently associated with an IOAS when it is created, remove
the strange situation where a refcount != 0 HWPT can have been
disconnected from the IOAS by putting all the IOAS related destruction in
the object destroy function.

Initializing a HWPT is two stages, we have to allocate it, attach it to a
device and then populate the domain. Once the domain is populated it is
fully linked to the IOAS.

Arrange things so that all the error unwinds flow through the
iommufd_hw_pagetable_destroy() and allow it to handle all cases.

Link: https://lore.kernel.org/r/4-v3-ae9c2975a131+2e1e8-iommufd_hwpt_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-03-06 10:51:57 -04:00
Jason Gunthorpe
342b9cab8e iommufd: Consistently manage hwpt_item
This should be added immediately after every iopt_table_add_domain(), and
deleted after every iopt_table_remove_domain() under the ioas->mutex.

Tidy things to be consistent.

Link: https://lore.kernel.org/r/3-v3-ae9c2975a131+2e1e8-iommufd_hwpt_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-03-06 10:51:57 -04:00
Jason Gunthorpe
7214c1c85f iommufd: Add iommufd_lock_obj() around the auto-domains hwpts
A later patch will require this locking - currently under the ioas mutex
the hwpt can not have a 0 reference and be on the list.

Link: https://lore.kernel.org/r/2-v3-ae9c2975a131+2e1e8-iommufd_hwpt_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-03-06 10:51:56 -04:00
Jason Gunthorpe
085fcc7eb7 iommufd: Assert devices_lock for iommufd_hw_pagetable_has_group()
The hwpt->devices list is locked by this, make it clearer.

Link: https://lore.kernel.org/r/1-v3-ae9c2975a131+2e1e8-iommufd_hwpt_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-03-06 10:51:56 -04:00
Jason Gunthorpe
b4ff830eca iommufd: Do not add the same hwpt to the ioas->hwpt_list twice
The hwpt is added to the hwpt_list only during its creation, it is never
added again. This hunk is some missed leftover from rework. Adding it
twice will corrupt the linked list in some cases.

It effects HWPT specific attachment, which is something the test suite
cannot cover until we can create a legitimate struct device with a
non-system iommu "driver" (ie we need the bus removed from the iommu code)

Cc: stable@vger.kernel.org
Fixes: e8d5721003 ("iommufd: Add kAPI toward external drivers for physical devices")
Link: https://lore.kernel.org/r/1-v1-4336b5cb2fe4+1d7-iommufd_hwpt_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reported-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-02-15 21:37:48 -04:00
Jason Gunthorpe
25fc417f79 iommufd: Convert to msi_device_has_isolated_msi()
Trivially use the new API.

Link: https://lore.kernel.org/r/4-v3-3313bb5dd3a3+10f11-secure_msi_jgg@nvidia.com
Tested-by: Matthew Rosato <mjrosato@linux.ibm.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>
2023-01-11 16:27:23 -04:00
Jason Gunthorpe
d6c55c0a20 iommufd: Change the order of MSI setup
Eric points out this is wrong for the rare case of someone using
allow_unsafe_interrupts on ARM. We always have to setup the MSI window in
the domain if the iommu driver asks for it.

Move the iommu_get_msi_cookie() setup to the top of the function and
always do it, regardless of the security mode. Add checks to
iommufd_device_setup_msi() to ensure the driver is not doing something
incomprehensible. No current driver will set both a HW and SW MSI window,
or have more than one SW MSI window.

Fixes: e8d5721003 ("iommufd: Add kAPI toward external drivers for physical devices")
Link: https://lore.kernel.org/r/3-v1-0362a1a1c034+98-iommufd_fixes1_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reported-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-12-09 15:24:30 -04:00
Jason Gunthorpe
52f528583b iommufd: Add additional invariant assertions
These are on performance paths so we protect them using the
CONFIG_IOMMUFD_TEST to not take a hit during normal operation.

These are useful when running the test suite and syzkaller to find data
structure inconsistencies early.

Link: https://lore.kernel.org/r/18-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> # s390
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-11-30 20:16:49 -04:00
Jason Gunthorpe
f4b20bb34c iommufd: Add kernel support for testing iommufd
Provide a mock kernel module for the iommu_domain that allows it to run
without any HW and the mocking provides a way to directly validate that
the PFNs loaded into the iommu_domain are correct. This exposes the access
kAPI toward userspace to allow userspace to explore the functionality of
pages.c and io_pagetable.c

The mock also simulates the rare case of PAGE_SIZE > iommu page size as
the mock will operate at a 2K iommu page size. This allows exercising all
of the calculations to support this mismatch.

This is also intended to support syzkaller exploring the same space.

However, it is an unusually invasive config option to enable all of
this. The config option should not be enabled in a production kernel.

Link: https://lore.kernel.org/r/16-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> # s390
Tested-by: Eric Auger <eric.auger@redhat.com> # aarch64
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-11-30 20:16:49 -04:00
Jason Gunthorpe
8d40205f60 iommufd: Add kAPI toward external drivers for kernel access
Kernel access is the mode that VFIO "mdevs" use. In this case there is no
struct device and no IOMMU connection. iommufd acts as a record keeper for
accesses and returns the actual struct pages back to the caller to use
however they need. eg with kmap or the DMA API.

Each caller must create a struct iommufd_access with
iommufd_access_create(), similar to how iommufd_device_bind() works. Using
this struct the caller can access blocks of IOVA using
iommufd_access_pin_pages() or iommufd_access_rw().

Callers must provide a callback that immediately unpins any IOVA being
used within a range. This happens if userspace unmaps the IOVA under the
pin.

The implementation forwards the access requests directly to the iopt
infrastructure that manages the iopt_pages_access.

Link: https://lore.kernel.org/r/14-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-11-30 20:16:49 -04:00
Jason Gunthorpe
e8d5721003 iommufd: Add kAPI toward external drivers for physical devices
Add the four functions external drivers need to connect physical DMA to
the IOMMUFD:

iommufd_device_bind() / iommufd_device_unbind()
  Register the device with iommufd and establish security isolation.

iommufd_device_attach() / iommufd_device_detach()
  Connect a bound device to a page table

Binding a device creates a device object ID in the uAPI, however the
generic API does not yet provide any IOCTLs to manipulate them.

Link: https://lore.kernel.org/r/13-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2022-11-30 20:16:49 -04:00