Re: [PATCH v1 0/19] cxl: Add CXL feature commands support via fwctl

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

On Wed, 22 Jan 2025 16:50:31 -0700
Dave Jiang <dave.jiang@intel.com> wrote:

> v1:
> - Create a CXL features driver to handle all feature command related bits
>   including FWCTL support. (Dan)
> - Tested against CXL CLI unit tests for FWCTL.
> - See individual patches for detailed changes from RFC v2.
> 
> RFC v2:
> - Dropped 1/13 and 2/13 from previous version. Merged upstream already.
> - Combined changes from Shiju for "get supported features"
> - Addressed comments from Jonathan and Jason
> - See specific changes in individual patch revision history
> - Added hardware command info to FWCTL
> - Added filtering to set feature command
> - Added documentation
> 
> This series add support for CXL feature commands using the FWCTL framework [1].
> The code has been tested with CXL CLI unit tests for FWCTL.
> 
> Patches 1-7 are shared with EDAC series [1] and there will be an immuable branch
> once accepted post review.

Looks like immutable should be maybe 3-8?  Perhaps reorder for next version
as odd to have middle of series in an immutable branch.

> 
> A CXL features driver is created to handle all CXL mailbox feature commands related
> functionalities as suggested by Dan. The 3 mailbox commands "Get Supported Features",
> "Get Feature", and "Set Feature" are implemented. The "get" commands under the
> FWCTL_RPC_CONFIGURATION policy, the "set" command checks the policy depending
> on the effect of the feature. All mailbox commands for CXL provides an effects
> table that describes the effects of a command when performed on the device.
> For CXL features, there is also an effects field that describes the effects
> a feature write operation has on the device per feature. The security policy
> is checked against this feature specific effects field. Looking for discussion
> on matching the CXL spec defined effects with the FWCTL security policy.
> 
> The code is based off of v3 of FWCTL series [2] posted by Jason and rebased on top of
> v6.13-rc5.
> 
> [1]: https://lore.kernel.org/linux-cxl/20250106121017.1620-1-shiju.jose@huawei.com/T/#t
> [2]: https://lore.kernel.org/linux-cxl/0-v3-960f17f90f17+516-fwctl_jgg@nvidia.com/#r
> ---
> 
> Dave Jiang (17):
>       cxl: Refactor user ioctl command path from mds to mailbox
>       cxl: Add skeletal features driver
>       cxl: Enumerate feature commands
>       cxl: Add Get Supported Features command for kernel usage
>       cxl: Add features driver attribute to emit number of features supported
>       cxl/test: Add Get Supported Features mailbox command support
>       cxl: Setup exclusive CXL features that are reserved for the kernel
>       cxl: Add FWCTL support to the CXL features driver
>       cxl: Add support for get driver information
>       cxl: Move cxl_mem.h under uapi to cxl exclusive directory
>       cxl: Move cxl feature command structs to user header
>       cxl: Add support for fwctl RPC command to enable CXL feature commands
>       cxl: Add support to handle user feature commands for get feature
>       cxl: Add support to handle user feature commands for set feature
>       cxl/test: Add Get Feature support to cxl_test
>       cxl/test: Add Set Feature support to cxl_test
>       fwctl/cxl: Add documentation to FWCTL CXL
> 
> Shiju Jose (2):
>       cxl/mbox: Add GET_FEATURE mailbox command
>       cxl/mbox: Add SET_FEATURE mailbox command
> 
>  Documentation/userspace-api/fwctl/fwctl-cxl.rst |  81 +++++++
>  Documentation/userspace-api/fwctl/index.rst     |   1 +
>  drivers/cxl/Kconfig                             |   9 +
>  drivers/cxl/Makefile                            |   3 +
>  drivers/cxl/core/Makefile                       |   1 +
>  drivers/cxl/core/core.h                         |   7 +-
>  drivers/cxl/core/features.c                     | 287 +++++++++++++++++++++++
>  drivers/cxl/core/mbox.c                         | 143 ++++++++----
>  drivers/cxl/core/memdev.c                       |  22 +-
>  drivers/cxl/core/port.c                         |   3 +
>  drivers/cxl/cxl.h                               |   3 +
>  drivers/cxl/cxlmem.h                            |  45 +---
>  drivers/cxl/features.c                          | 558 ++++++++++++++++++++++++++++++++++++++++++++
>  drivers/cxl/pci.c                               |  19 ++
>  include/cxl/features.h                          |  75 ++++++
>  include/cxl/mailbox.h                           |  46 +++-
>  include/uapi/cxl/features.h                     | 135 +++++++++++
>  include/uapi/{linux/cxl_mem.h => cxl/mem.h}     |   0
>  include/uapi/fwctl/cxl.h                        |  60 +++++
>  include/uapi/fwctl/fwctl.h                      |   1 +
>  tools/testing/cxl/Kbuild                        |   1 +
>  tools/testing/cxl/test/mem.c                    | 194 +++++++++++++++
>  22 files changed, 1597 insertions(+), 97 deletions(-)