On 22/10/24 11:20, Nicolin Chen wrote:
Following the previous vIOMMU series, this adds another vDEVICE structure,
representing the association from an iommufd_device to an iommufd_viommu.
This gives the whole architecture a new "v" layer:
_______________________________________________________________________
| iommufd (with vIOMMU/vDEVICE) |
| _____________ _____________ |
| | | | | |
| |----------------| vIOMMU |<---| vDEVICE |<------| |
| | | | |_____________| | |
| | ______ | | _____________ ___|____ |
| | | | | | | | | | |
| | | IOAS |<---|(HWPT_PAGING)|<---| HWPT_NESTED |<--| DEVICE | |
| | |______| |_____________| |_____________| |________| |
|______|________|______________|__________________|_______________|_____|
| | | | |
______v_____ | ______v_____ ______v_____ ___v__
| struct | | PFN | (paging) | | (nested) | |struct|
|iommu_device| |------>|iommu_domain|<----|iommu_domain|<----|device|
|____________| storage|____________| |____________| |______|
This vDEVICE object is used to collect and store all vIOMMU-related device
information/attributes in a VM. As an initial series for vDEVICE, add only
the virt_id to the vDEVICE, which is a vIOMMU specific device ID in a VM:
e.g. vSID of ARM SMMUv3, vDeviceID of AMD IOMMU, and vID of Intel VT-d to
a Context Table. This virt_id helps IOMMU drivers to link the vID to a pID
of the device against the physical IOMMU instance. This is essential for a
vIOMMU-based invalidation, where the request contains a device's vID for a
device cache flush, e.g. ATC invalidation.
Therefore, with this vDEVICE object, support a vIOMMU-based invalidation,
by reusing IOMMUFD_CMD_HWPT_INVALIDATE for a vIOMMU object to flush cache
with a given driver data.
As for the implementation of the series, add driver support in ARM SMMUv3
for a real world use case.
This series is on Github:
https://github.com/nicolinc/iommufd/commits/iommufd_viommu_p2-v4
For testing, try this "with-rmr" branch:
https://github.com/nicolinc/iommufd/commits/iommufd_viommu_p2-v4-with-rmr
Is there any real example of a .vdevice_alloc hook, besides the
selftests? It is not in iommufd_viommu_p2-v4-with-rmr, hence the
question. I am trying to sketch something with this new machinery and
less guessing would be nice. Thanks,
Paring QEMU branch for testing:
https://github.com/nicolinc/qemu/commits/wip/for_iommufd_viommu_p2-v4
Changelog
v4
* Added missing brackets in switch-case
* Fixed the unreleased idev refcount issue
* Reworked the iommufd_vdevice_alloc allocator
* Dropped support for IOMMU_VIOMMU_TYPE_DEFAULT
* Added missing TEST_LENGTH and fail_nth coverages
* Added a verification to the driver-allocated vDEVICE object
* Added an iommufd_vdevice_abort for a missing mutex protection
* Added a u64 structure arm_vsmmu_invalidation_cmd for user command
conversion
v3
https://lore.kernel.org/all/cover.1728491532.git.nicolinc@xxxxxxxxxx/
* Added Jason's Reviewed-by
* Split this invalidation part out of the part-1 series
* Repurposed VDEV_ID ioctl to a wider vDEVICE structure and ioctl
* Reduced viommu_api functions by allowing drivers to access viommu
and vdevice structure directly
* Dropped vdevs_rwsem by using xa_lock instead
* Dropped arm_smmu_cache_invalidate_user
v2
https://lore.kernel.org/all/cover.1724776335.git.nicolinc@xxxxxxxxxx/
* Limited vdev_id to one per idev
* Added a rw_sem to protect the vdev_id list
* Reworked driver-level APIs with proper lockings
* Added a new viommu_api file for IOMMUFD_DRIVER config
* Dropped useless iommu_dev point from the viommu structure
* Added missing index numnbers to new types in the uAPI header
* Dropped IOMMU_VIOMMU_INVALIDATE uAPI; Instead, reuse the HWPT one
* Reworked mock_viommu_cache_invalidate() using the new iommu helper
* Reordered details of set/unset_vdev_id handlers for proper lockings
v1
https://lore.kernel.org/all/cover.1723061377.git.nicolinc@xxxxxxxxxx/
Thanks!
Nicolin
Jason Gunthorpe (2):
iommu: Add iommu_copy_struct_from_full_user_array helper
iommu/arm-smmu-v3: Allow ATS for IOMMU_DOMAIN_NESTED
Nicolin Chen (12):
iommufd/viommu: Introduce IOMMUFD_OBJ_VDEVICE and its related struct
iommufd/viommu: Add IOMMU_VDEVICE_ALLOC ioctl
iommufd/selftest: Add IOMMU_VDEVICE_ALLOC test coverage
iommu/viommu: Add cache_invalidate to iommufd_viommu_ops
iommufd/hw_pagetable: Enforce cache invalidation op on vIOMMU-based
hwpt_nested
iommufd: Allow hwpt_id to carry viommu_id for IOMMU_HWPT_INVALIDATE
iommufd/viommu: Add vdev_to_dev helper
iommufd/selftest: Add mock_viommu_cache_invalidate
iommufd/selftest: Add IOMMU_TEST_OP_DEV_CHECK_CACHE test command
iommufd/selftest: Add vIOMMU coverage for IOMMU_HWPT_INVALIDATE ioctl
Documentation: userspace-api: iommufd: Update vDEVICE
iommu/arm-smmu-v3: Add arm_vsmmu_cache_invalidate
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 9 +-
drivers/iommu/iommufd/iommufd_private.h | 12 ++
drivers/iommu/iommufd/iommufd_test.h | 30 +++
include/linux/iommu.h | 49 ++++-
include/linux/iommufd.h | 50 +++++
include/uapi/linux/iommufd.h | 61 +++++-
tools/testing/selftests/iommu/iommufd_utils.h | 83 +++++++
.../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 162 +++++++++++++-
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 32 ++-
drivers/iommu/iommufd/device.c | 11 +
drivers/iommu/iommufd/driver.c | 7 +
drivers/iommu/iommufd/hw_pagetable.c | 36 +++-
drivers/iommu/iommufd/main.c | 7 +
drivers/iommu/iommufd/selftest.c | 115 +++++++++-
drivers/iommu/iommufd/viommu.c | 108 ++++++++++
tools/testing/selftests/iommu/iommufd.c | 204 +++++++++++++++++-
.../selftests/iommu/iommufd_fail_nth.c | 4 +
Documentation/userspace-api/iommufd.rst | 41 +++-
18 files changed, 983 insertions(+), 38 deletions(-)
--
Alexey
