Re: [PATCH v3 00/10] Introduce fwctl subystem

Dave Jiang
2024-09-13T22:40:00Z

On 8/21/24 11:10 AM, Jason Gunthorpe wrote:
> fwctl is a new subsystem intended to bring some common rules and order to
> the growing pattern of exposing a secure FW interface directly to
> userspace. Unlike existing places like RDMA/DRM/VFIO/uacce that are
> exposing a device for datapath operations fwctl is focused on debugging,
> configuration and provisioning of the device. It will not have the
> necessary features like interrupt delivery to support a datapath.
>
> This concept is similar to the long standing practice in the "HW" RAID
> space of having a device specific misc device to manager the RAID
> controller FW. fwctl generalizes this notion of a companion debug and
> management interface that goes along with a dataplane implemented in an
> appropriate subsystem.
>
> The need for this has reached a critical point as many users are moving to
> run lockdown enabled kernels. Several existing devices have had long
> standing tooling for management that relied on /sys/../resource0 or PCI
> config space access which is not permitted in lockdown. A major point of
> fwctl is to define and document the rules that a device must follow to
> expose a lockdown compatible RPC.
>
> Based on some discussion fwctl splits the RPCs into four categories
>
> FWCTL_RPC_CONFIGURATION
> FWCTL_RPC_DEBUG_READ_ONLY
> FWCTL_RPC_DEBUG_WRITE
> FWCTL_RPC_DEBUG_WRITE_FULL
>
> Where the latter two trigger a new TAINT_FWCTL, and the final one requires
> CAP_SYS_RAWIO - excluding it from lockdown. The device driver and its FW
> would be responsible to restrict RPCs to the requested security scope,
> while the core code handles the tainting and CAP checks.
>
> For details see the final patch which introduces the documentation.
>
> This series incorporates a version of the mlx5ctl interface previously
> proposed:
> https://lore.kernel.org/r/20240207072435.14182-1-saeed@kernel.org/
>
> For this series the memory registration mechanism was removed, but I
> expect it will come back.
>
> It also includes the FWCL driver series from David:
> https://lore.kernel.org/all/20240718213446.1750135-1-dave.jiang@intel.com/
>
>
> This is still waiting a 3rd fwctl driver and the CXL side to finish some
> of its development. The github has the necessary CXL precursor patches.
>
> There have been two LWN articles written discussing various aspects of
> this proposal:
>
> https://lwn.net/Articles/955001/
> https://lwn.net/Articles/969383/
>
> And a really giant ksummit thread:
>
> https://lore.kernel.org/ksummit/668c67a324609_ed99294c0@dwillia2-xfh.jf.intel.com.notmuch/
>
> Several have expressed general support for this concept:
>
> Broadcom Networking - https://lore.kernel.org/r/Zf2n02q0GevGdS-Z@C02YVCJELVCG
> Christoph Hellwig - https://lore.kernel.org/r/Zcx53N8lQjkpEu94@infradead.org/
> Daniel Vetter - https://lore.kernel.org/r/ZrHY2Bds7oF7KRGz@phenom.ffwll.local
> Enfabrica - https://lore.kernel.org/r/9cc7127f-8674-43bc-b4d7-b1c4c2d96fed@kernel.org/
> NVIDIA Networking
> Oded Gabbay/Habana - https://lore.kernel.org/r/ZrMl1bkPP-3G9B4N@T14sgabbay.
> Oracle Linux - https://lore.kernel.org/r/6lakj6lxlxhdgrewodvj3xh6sxn3d36t5dab6najzyti2navx3@wrge7cyfk6nq
> SuSE/Hannes - https://lore.kernel.org/r/2fd48f87-2521-4c34-8589-dbb7e91bb1c8@suse.com
>
> Work is ongoing for a robust multi-device open source userspace, currently
> the mlx5ctl_user that was posted by Saeed has been updated to use fwctl.
>
> https://github.com/saeedtx/mlx5ctl.git
> https://github.com/jgunthorpe/mlx5ctl.git
>
> This is on github: https://github.com/jgunthorpe/linux/commits/fwctl
>
> v3:
> - Rebase to v6.11-rc4
> - Add a squashed version of David's CXL series as the 2nd driver
> - Add missing includes
> - Improve comments based on feedback
> - Use the kdoc format that puts the member docs inside the struct
> - Rewrite fwctl_alloc_device() to be clearer
> - Incorporate all remarks for the documentation
> v2: https://lore.kernel.org/r/0-v2-940e479ceba9+3821-fwctl_jgg@nvidia.com
> - Rebase to v6.10-rc5
> - Minor style changes
> - Follow the style consensus for the guard stuff
> - Documentation grammer/spelling
> - Add missed length output for mlx5 get_info
> - Add two more missed MLX5 CMD's
> - Collect tags
> v1: https://lore.kernel.org/r/0-v1-9912f1a11620+2a-fwctl_jgg@nvidia.com
>
> Cc: Andy Gospodarek <andrew.gospodarek@broadcom.com>
> Cc: Aron Silverton <aron.silverton@oracle.com>
> Cc: Christoph Hellwig <hch@infradead.org>
> Cc: David Ahern <dsahern@kernel.org>
> Cc: Itay Avraham <itayavr@nvidia.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Jiri Pirko <jiri@nvidia.com>
> Cc: Leon Romanovsky <leonro@nvidia.com>
> Cc: Leonid Bloch <lbloch@nvidia.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: linux-cxl@vger.kernel.org
> Cc: linux-rdma@vger.kernel.org
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
>
> Dave Jiang (1):
> fwctl/cxl: Add driver for CXL mailbox for handling CXL features
> commands (RFC)
>
> Jason Gunthorpe (7):
> fwctl: Add basic structure for a class subsystem with a cdev
> fwctl: Basic ioctl dispatch for the character device
> fwctl: FWCTL_INFO to return basic information about the device
> taint: Add TAINT_FWCTL
> fwctl: FWCTL_RPC to execute a Remote Procedure Call to device firmware
> fwctl: Add documentation
> cxl: Create an auxiliary device for fwctl_cxl
>
> Saeed Mahameed (2):
> fwctl/mlx5: Support for communicating with mlx5 fw
> mlx5: Create an auxiliary device for fwctl_mlx5
>
> Documentation/admin-guide/tainted-kernels.rst | 5 +
> Documentation/userspace-api/fwctl.rst | 285 ++++++++++++
> Documentation/userspace-api/index.rst | 1 +
> .../userspace-api/ioctl/ioctl-number.rst | 1 +
> MAINTAINERS | 23 +
> drivers/Kconfig | 2 +
> drivers/Makefile | 1 +
> drivers/cxl/core/memdev.c | 19 +
> drivers/fwctl/Kconfig | 32 ++
> drivers/fwctl/Makefile | 6 +
> drivers/fwctl/cxl/Makefile | 4 +
> drivers/fwctl/cxl/cxl.c | 274 ++++++++++++
> drivers/fwctl/main.c | 414 ++++++++++++++++++
> drivers/fwctl/mlx5/Makefile | 4 +
> drivers/fwctl/mlx5/main.c | 337 ++++++++++++++
> drivers/net/ethernet/mellanox/mlx5/core/dev.c | 8 +
> include/linux/cxl/mailbox.h | 104 +++++
> include/linux/fwctl.h | 135 ++++++
> include/linux/panic.h | 3 +-
> include/uapi/fwctl/cxl.h | 94 ++++
> include/uapi/fwctl/fwctl.h | 140 ++++++
> include/uapi/fwctl/mlx5.h | 36 ++
> kernel/panic.c | 1 +
> tools/debugging/kernel-chktaint | 8 +
> 24 files changed, 1936 insertions(+), 1 deletion(-)
> create mode 100644 Documentation/userspace-api/fwctl.rst
> create mode 100644 drivers/fwctl/Kconfig
> create mode 100644 drivers/fwctl/Makefile
> create mode 100644 drivers/fwctl/cxl/Makefile
> create mode 100644 drivers/fwctl/cxl/cxl.c
> create mode 100644 drivers/fwctl/main.c
> create mode 100644 drivers/fwctl/mlx5/Makefile
> create mode 100644 drivers/fwctl/mlx5/main.c
> create mode 100644 include/linux/fwctl.h
> create mode 100644 include/uapi/fwctl/cxl.h
> create mode 100644 include/uapi/fwctl/fwctl.h
> create mode 100644 include/uapi/fwctl/mlx5.h
>
>
> base-commit: cd0c76bee95e9c2092418523599439d2c8dbff7e

Hi Jason,
Which base-commit is this? I'm not finding the hash in the upstream tree. I'm having trouble applying the series against 6.10 or 6.11-rc7 via b4.