| Message ID | cover.1728491453.git.nicolinc@nvidia.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | cover-letter: iommufd: Add vIOMMU infrastructure (Part-1) | expand |
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-v3
Paring QEMU branch for testing:
https://github.com/nicolinc/qemu/commits/wip/for_iommufd_viommu_p2-v3
Changelog
v3
* 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@nvidia.com/
* 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@nvidia.com/
Thanks!
Nicolin
Jason Gunthorpe (3):
iommu: Add iommu_copy_struct_from_full_user_array helper
iommu/arm-smmu-v3: Allow ATS for IOMMU_DOMAIN_NESTED
iommu/arm-smmu-v3: Update comments about ATS and bypass
Nicolin Chen (13):
iommufd/viommu: Introduce IOMMUFD_OBJ_VDEVICE and its related struct
iommufd/viommu: Add a default_viommu_ops for IOMMU_VIOMMU_TYPE_DEFAULT
iommufd/viommu: Add IOMMU_VDEVICE_ALLOC ioctl
iommufd/selftest: Add IOMMU_VDEVICE_ALLOC test coverage
iommu/viommu: Add cache_invalidate for IOMMU_VIOMMU_TYPE_DEFAULT
iommufd/hw_pagetable: Allow viommu->ops->cache_invalidate for
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 | 53 ++++-
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 | 50 +++--
drivers/iommu/iommufd/hw_pagetable.c | 45 +++-
drivers/iommu/iommufd/main.c | 6 +
drivers/iommu/iommufd/selftest.c | 122 ++++++++++-
drivers/iommu/iommufd/viommu.c | 93 +++++++-
drivers/iommu/iommufd/viommu_api.c | 21 ++
tools/testing/selftests/iommu/iommufd.c | 204 +++++++++++++++++-
Documentation/userspace-api/iommufd.rst | 58 +++--
16 files changed, 1007 insertions(+), 52 deletions(-)
On Wed, Oct 09, 2024 at 09:38:12AM -0700, 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: Don't thread series together like this with reply-to, it breaks b4 and other tools ability to tell them apart.. Just post them separately normally. Jason
On Thu, Oct 17, 2024 at 04:14:16PM -0300, Jason Gunthorpe wrote: > On Wed, Oct 09, 2024 at 09:38:12AM -0700, 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: > > Don't thread series together like this with reply-to, it breaks b4 and > other tools ability to tell them apart.. Just post them separately > normally. Yea, I didn't expect a single git-send-mail would thread them together. Will do separately next time. Thanks Nicolin
This series introduces a new vIOMMU infrastructure and related ioctls. IOMMUFD has been using the HWPT infrastructure for all cases, including a nested IO page table support. Yet, there're limitations for an HWPT-based structure to support some advanced HW-accelerated features, such as CMDQV on NVIDIA Grace, and HW-accelerated vIOMMU on AMD. Even for a multi-IOMMU environment, it is not straightforward for nested HWPTs to share the same parent HWPT (stage-2 IO pagetable), with the HWPT infrastructure alone: a parent HWPT typically hold one stage-2 IO pagetable and tag it with only one ID in the cache entries. When sharing one large stage-2 IO pagetable across physical IOMMU instances, that one ID may not always be available across all the IOMMU instances. In other word, it's ideal for SW to have a different container for the stage-2 IO pagetable so it can hold another ID that's available. For this "different container", add vIOMMU, an additional layer to hold extra virtualization information: _______________________________________________________________________ | iommufd (with vIOMMU) | | | | [5] | | _____________ | | | | | | [1] | vIOMMU | [4] [2] | | ________________ | | _____________ ________ | | | | | [3] | | | | | | | | IOAS |<---|(HWPT_PAGING)|<---| HWPT_NESTED |<--| DEVICE | | | |________________| |_____________| |_____________| |________| | | | | | | | |_________|____________________|__________________|_______________|_____| | | | | | ______v_____ ______v_____ ___v__ | PFN storage | (paging) | | (nested) | |struct| |------------>|iommu_domain|<----|iommu_domain|<----|device| |____________| |____________| |______| The vIOMMU object should be seen as a slice of a physical IOMMU instance that is passed to or shared with a VM. That can be some HW/SW resources: - Security namespace for guest owned ID, e.g. guest-controlled cache tags - Access to a sharable nesting parent pagetable across physical IOMMUs - Virtualization of various platforms IDs, e.g. RIDs and others - Delivery of paravirtualized invalidation - Direct assigned invalidation queues - Direct assigned interrupts - Non-affiliated event reporting On a multi-IOMMU system, the vIOMMU object must be instanced to the number of the physical IOMMUs that are passed to (via devices) a guest VM, while being able to hold the shareable parent HWPT. Each vIOMMU then just needs to allocate its own individual ID to tag its own cache: ---------------------------- ---------------- | | paging_hwpt0 | | hwpt_nested0 |--->| viommu0 ------------------ ---------------- | | IDx | ---------------------------- ---------------------------- ---------------- | | paging_hwpt0 | | hwpt_nested1 |--->| viommu1 ------------------ ---------------- | | IDy | ---------------------------- As an initial part-1, add IOMMUFD_CMD_VIOMMU_ALLOC ioctl for an allocation only. Later series will add more data structures and their ioctls. As for the implementation of the series, add an IOMMU_VIOMMU_TYPE_DEFAULT type for a core-allocated-core-managed vIOMMU object, allowing drivers to simply hook a default viommu ops for viommu-based invalidation alone. And add support for driver-specific type of vIOMMU allocation, and implement that in the ARM SMMUv3 driver for a real world use case. More vIOMMU-based structs and ioctls will be introduced in the follow-up series to support vDEVICE, vIRQ (vEVENT) and VQUEUE objects. Although we repurposed the vIOMMU object from an earlier RFC, just for a referece: https://lore.kernel.org/all/cover.1712978212.git.nicolinc@nvidia.com/ This series is on Github: https://github.com/nicolinc/iommufd/commits/iommufd_viommu_p1-v3 (paring QEMU branch for testing will be provided with the part2 series) Changelog v3 * Rebased on top of Jason's nesting v3 series https://lore.kernel.org/all/0-v3-e2e16cd7467f+2a6a1-smmuv3_nesting_jgg@nvidia.com/ * Split the series into smaller parts * Added Jason's Reviewed-by * Added back viommu->iommu_dev * Added support for driver-allocated vIOMMU v.s. core-allocated * Dropped arm_smmu_cache_invalidate_user * Added an iommufd_test_wait_for_users() in selftest * Reworked test code to make viommu an individual FIXTURE * Added missing TEST_LENGTH case for the new ioctl command v2 https://lore.kernel.org/all/cover.1724776335.git.nicolinc@nvidia.com/ * 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@nvidia.com/ Thanks! Nicolin Nicolin Chen (11): iommufd: Move struct iommufd_object to public iommufd header iommufd: Rename _iommufd_object_alloc to iommufd_object_alloc_elm iommufd: Introduce IOMMUFD_OBJ_VIOMMU and its related struct iommufd/viommu: Add IOMMU_VIOMMU_ALLOC ioctl iommu: Pass in a viommu pointer to domain_alloc_user op iommufd: Allow pt_id to carry viommu_id for IOMMU_HWPT_ALLOC iommufd/selftest: Add refcount to mock_iommu_device iommufd/selftest: Add IOMMU_VIOMMU_TYPE_SELFTEST iommufd/selftest: Add IOMMU_VIOMMU_ALLOC test coverage Documentation: userspace-api: iommufd: Update vIOMMU iommu/arm-smmu-v3: Add IOMMU_VIOMMU_TYPE_ARM_SMMUV3 support drivers/iommu/iommufd/Makefile | 5 +- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 18 ++++ drivers/iommu/iommufd/iommufd_private.h | 23 ++--- drivers/iommu/iommufd/iommufd_test.h | 2 + include/linux/iommu.h | 15 +++ include/linux/iommufd.h | 52 +++++++++++ include/uapi/linux/iommufd.h | 54 +++++++++-- tools/testing/selftests/iommu/iommufd_utils.h | 28 ++++++ drivers/iommu/amd/iommu.c | 1 + .../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 24 +++++ drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 + drivers/iommu/intel/iommu.c | 1 + drivers/iommu/iommufd/hw_pagetable.c | 27 +++++- drivers/iommu/iommufd/main.c | 38 ++------ drivers/iommu/iommufd/selftest.c | 79 ++++++++++++++-- drivers/iommu/iommufd/viommu.c | 91 +++++++++++++++++++ drivers/iommu/iommufd/viommu_api.c | 57 ++++++++++++ tools/testing/selftests/iommu/iommufd.c | 84 +++++++++++++++++ Documentation/userspace-api/iommufd.rst | 66 +++++++++++++- 19 files changed, 602 insertions(+), 65 deletions(-) create mode 100644 drivers/iommu/iommufd/viommu.c create mode 100644 drivers/iommu/iommufd/viommu_api.c