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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Extends iommufd_hw_pagetable_alloc() to accept user flags, the uAPI will
provide the flags.
Link: https://lore.kernel.org/r/20230928071528.26258-4-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Make IOMMUFD use iommu_domain_alloc_user() by default for iommu_domain
creation. IOMMUFD needs to support iommu_domain allocation with parameters
from userspace in nested support, and a driver is expected to implement
everything under this op.
If the iommu driver doesn't provide domain_alloc_user callback then
IOMMUFD falls back to use iommu_domain_alloc() with an UNMANAGED type if
possible.
Link: https://lore.kernel.org/r/20230928071528.26258-3-yi.l.liu@intel.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.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>
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
...
- 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()
...
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>
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>
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>
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>
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>
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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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
