Introduce mlx5 DEVX interface

From: Leon Romanovsky <[email protected]>

Changelog:
v1->v2:
* Rebase on top of v4.18-rc1
v0 -> v1:
* Dropped few validation/debug patches from the KABI part as of Jason's comments.
* Use kvmalloc/kvfree instead of kmalloc/kfree to prevent higher order allocation under user control.
* Cleaned up a dependency of CONFIG_INFINIBAND_USER_ACCESS from the uverbs layer.
* Moved to white list command mode.
* Serialize access to DEVX object - odify/read new methods were added
with the appropriate IDR lock.
* Block DEVX on IB port as of SELinux.
* Improve uverbs_cleanup_ucontext algorithm to support two objects from the same type.
* Fix mlx5_ifc.h to use reserved_at_xxx.
* Enforce devx_uid existence upon DEVX methods.

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This DEVX series enables direct access from the user space area to the mlx5 device driver by using the KABI mechanism.

The main purpose here is to make the user space driver as independent as possible from the kernel so that future device functionality and commands can be activated with minimal to none kernel changes.

The series keeps the same level of user process security/isolation as provided today by the kernel IB verbs by using a user id returned from the firmware upon context creation.

This user id is put by the kernel code in all firmware command from the DEVX interface so that the isolation/security will be enforced by the firmware based on that id.

Below kernel services are exposed to let the above work:

1) Expose a DEVX object that represent some underlay firmware object, the input command to create it is some raw data given by the user application which should match the device specification.

2) Expose a UMEM DEVX object for user memory registration for DMA:
The driver provides an API to register user memory, getting as input the user address, length and access flags, and provides to the user as output an ID (UMEM ID) returned by the firmware to this registered memory.

The user will use that UMEM ID in device direct commands that use this memory instead of the physical addresses list.

3) Expose device general command API:
The driver provides an API to issue some general command except than create and destroy.

4) UAR mapping:
Returns a device UAR ID for a given user index by using the kernel context information.

This is safe from security point of view as described in details in the relevant patch in the series.

5) EQ mapping:
Returns the matching device EQN for a given user vector number via the DEVX interface.

6) Process resources cleanup:
This is achieved by the existing kernel KABI logic, upon DEVX object creation the kernel builds the FW destroy command inbox in the KABI object and uses it upon cleanup.

7) Future device commands:
This will be supported by some general command type (create, destroy) that the DEVX code embeds as part of its code and is going to be used from now on by the firmware.

At the beginning of this series there are some KABI infra-structures improvements and fixes to enable the above DEVX functionality in a cleaner way.

More details appear as part of the commit logs of the series and as part of the comments in the code itself.

Thanks

Leon Romanovsky (2):
drm/i915: Move u64-to-ptr helpers to general header kernel.h: Reuse u64_to_ptr macro to cast __user pointers

Matan Barak (5):
IB/uverbs: Export uverbs idr and fd types
IB/uverbs: Refactor uverbs_finalize_objects
IB/uverbs: Add PTR_IN attributes that are allocated/copied
automatically
IB/uverbs: Add a macro to define a type with no kernel known size IB/uverbs: Allow an empty namespace in ioctl() framework

Yishai Hadas (13):
net/mlx5_core: Prevent warns in dmesg upon firmware commands IB/core: Improve uverbs_cleanup_ucontext algorithm net/mlx5: Expose DEVX ifc structures
IB/mlx5: Introduce DEVX
IB/core: Introduce DECLARE_UVERBS_GLOBAL_METHODS
IB: Expose ib_ucontext from a given ib_uverbs_file IB/mlx5: Add support for DEVX general command IB/mlx5: Add obj create and destroy functionality IB/mlx5: Add DEVX support for modify and query commands IB/mlx5: Add support for DEVX query UAR
IB/mlx5: Add DEVX support for memory registration IB/mlx5: Add DEVX query EQN support
IB/mlx5: Expose DEVX tree

 drivers/gpu/drm/i915/i915_utils.h                  |   12 +-
 drivers/infiniband/core/rdma_core.c                |  138 +--
 drivers/infiniband/core/rdma_core.h                |   10 +-
 drivers/infiniband/core/uverbs_ioctl.c             |  104 +-
 drivers/infiniband/core/uverbs_main.c              |    6 +
 drivers/infiniband/core/uverbs_std_types.c         |   26 +-
 .../infiniband/core/uverbs_std_types_counters.c    |    2 +-
 drivers/infiniband/core/uverbs_std_types_cq.c      |    2 +-
 drivers/infiniband/core/uverbs_std_types_dm.c      |    3 +-
 .../infiniband/core/uverbs_std_types_flow_action.c |    2 +-
 drivers/infiniband/core/uverbs_std_types_mr.c      |    3 +-
 drivers/infiniband/hw/mlx5/Makefile                |    1 +
 drivers/infiniband/hw/mlx5/devx.c                  | 1106 ++++++++++++++++++++
 drivers/infiniband/hw/mlx5/main.c                  |   31 +-
 drivers/infiniband/hw/mlx5/mlx5_ib.h               |   19 +
 drivers/infiniband/hw/mlx5/qp.c                    |    9 +-
 drivers/net/ethernet/mellanox/mlx5/core/cmd.c      |   24 +-
 include/linux/kernel.h                             |   11 +-
 include/linux/mlx5/device.h                        |    3 +
 include/linux/mlx5/mlx5_ifc.h                      |   71 +-
 include/rdma/ib_verbs.h                            |    4 +-
 include/rdma/uverbs_ioctl.h                        |   27 +
 include/rdma/uverbs_named_ioctl.h                  |    4 +
 include/rdma/uverbs_std_types.h                    |    2 -
 include/rdma/uverbs_types.h                        |   11 +-
 include/uapi/rdma/mlx5-abi.h                       |    3 +
 include/uapi/rdma/mlx5_user_ioctl_cmds.h           |   73 ++
 27 files changed, 1548 insertions(+), 159 deletions(-)
 create mode 100644 drivers/infiniband/hw/mlx5/devx.c