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

[Leon Romanovsky <leon@kernel.org>]

On Fri, Sep 13, 2024 at 03:39:57PM -0700, Dave Jiang wrote:
> 
> 
> 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. 

This base-commit very depends on there cover letter was generated and
stored while creating the series. In this specific case, Jason put cover
letter to be the last commit in the series, so the base-commit points to
the last patch cd0c76bee95e ("cxl: Infrastructure for fwctl").

Thanks