On 2/6/25 5:13 PM, Jason Gunthorpe wrote: > [ > Many people were away around the holiday period, but work is back in full > swing now with Dave already at v3 on his CXL work over the past couple > weeks. We are looking at a good chance of reaching this merge window. I > will work out some shared branches with CXL and get it into linux-next > once all three drivers can be assembled and reviews seem to be concluding. > > There are couple open notes > - Greg was interested in a new name, but nobody offered any bikesheds > - I would like a co-maintainer I volunteer as tribute. :) I got the CXL series rebased and tested on top of this series. So you can add Tested-by: Dave Jiang <dave.jiang@xxxxxxxxx> for the core FWCTL bits in the series. I'll post the CXL FWCTL series v4 shortly. DJ > ] > > 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 manage 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. > > The CXL FWCTL driver is now in it own series on v3: > https://lore.kernel.org/r/20250204220430.4146187-1-dave.jiang@xxxxxxxxx > > I'm expecting a 3rd driver (from Shannon @ Pensando) to be posted right > away, the github version I saw looked good. I've got soft commitments for > about 6 drivers in total now. > > There have been three LWN articles written discussing various aspects of > this proposal: > > https://lwn.net/Articles/955001/ > https://lwn.net/Articles/969383/ > https://lwn.net/Articles/990802/ > > A really giant ksummit thread preceding a discussion at the Maintainer > Summit: > > https://lore.kernel.org/ksummit/668c67a324609_ed99294c0@xxxxxxxxxxxxxxxxxxxxxxxxx.notmuch/ > > Several have expressed general support for this concept: > > AMD/Pensando - https://lore.kernel.org/linux-rdma/20241205222818.44439-1-shannon.nelson@xxxxxxx > Broadcom Networking - https://lore.kernel.org/r/Zf2n02q0GevGdS-Z@C02YVCJELVCG > Christoph Hellwig - https://lore.kernel.org/r/Zcx53N8lQjkpEu94@xxxxxxxxxxxxx > Daniel Vetter - https://lore.kernel.org/r/ZrHY2Bds7oF7KRGz@phenom.ffwll.local > Enfabrica - https://lore.kernel.org/r/9cc7127f-8674-43bc-b4d7-b1c4c2d96fed@xxxxxxxxxx > 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@xxxxxxxx > > Work is ongoing for userspace, currently the mellanox tool suite has been > ported over: > https://github.com/Mellanox/mstflint > > And a more simplified example how to use it: > https://github.com/jgunthorpe/mlx5ctl.git > > This is on github: https://github.com/jgunthorpe/linux/commits/fwctl > > v4: > - Rebase to v6.14-rc1 > - Fine tune comments and rst documentatin > - Adjust cleanup.h usage - remove places that add more ofuscation than > value > - CXL is back to its own independent series > - Increase FWCTL_MAX_DEVICES to 4096, someone hit the limit > - Fix mlx5ctl_validate_rpc() logic around scope checking > - Disable mlx5ctl on SFs > v3: https://patch.msgid.link/r/0-v3-960f17f90f17+516-fwctl_jgg@xxxxxxxxxx > - 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@xxxxxxxxxx > - 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@xxxxxxxxxx > > Andy Gospodarek (2): > fwctl/bnxt: Support communicating with bnxt fw > bnxt: Create an auxiliary device for fwctl_bnxt > > Jason Gunthorpe (6): > 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 > > 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/fwctl.rst | 285 ++++++++++++ > Documentation/userspace-api/fwctl/index.rst | 12 + > Documentation/userspace-api/index.rst | 1 + > .../userspace-api/ioctl/ioctl-number.rst | 1 + > MAINTAINERS | 16 + > drivers/Kconfig | 2 + > drivers/Makefile | 1 + > drivers/fwctl/Kconfig | 32 ++ > drivers/fwctl/Makefile | 6 + > drivers/fwctl/bnxt/Makefile | 4 + > drivers/fwctl/bnxt/bnxt.c | 167 +++++++ > drivers/fwctl/main.c | 416 ++++++++++++++++++ > drivers/fwctl/mlx5/Makefile | 4 + > drivers/fwctl/mlx5/main.c | 340 ++++++++++++++ > drivers/net/ethernet/broadcom/bnxt/bnxt.c | 3 + > drivers/net/ethernet/broadcom/bnxt/bnxt.h | 3 + > drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c | 126 +++++- > drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.h | 4 + > drivers/net/ethernet/mellanox/mlx5/core/dev.c | 9 + > include/linux/fwctl.h | 135 ++++++ > include/linux/panic.h | 3 +- > include/uapi/fwctl/bnxt.h | 27 ++ > include/uapi/fwctl/fwctl.h | 140 ++++++ > include/uapi/fwctl/mlx5.h | 36 ++ > kernel/panic.c | 1 + > tools/debugging/kernel-chktaint | 8 + > 27 files changed, 1782 insertions(+), 5 deletions(-) > create mode 100644 Documentation/userspace-api/fwctl/fwctl.rst > create mode 100644 Documentation/userspace-api/fwctl/index.rst > create mode 100644 drivers/fwctl/Kconfig > create mode 100644 drivers/fwctl/Makefile > create mode 100644 drivers/fwctl/bnxt/Makefile > create mode 100644 drivers/fwctl/bnxt/bnxt.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/bnxt.h > create mode 100644 include/uapi/fwctl/fwctl.h > create mode 100644 include/uapi/fwctl/mlx5.h > > > base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
