From: Jason Gunthorpe To: Jonathan Corbet , Itay Avraham , Jakub Kicinski , Leon Romanovsky , linux-doc@vger.kernel.org, linux-rdma@vger.kernel.org, netdev@vger.kernel.org, Paolo Abeni , Saeed Mahameed , Tariq Toukan Cc: Andy Gospodarek , Aron Silverton , Dan Williams , David Ahern , Christoph Hellwig , Jiri Pirko , Leonid Bloch , Leon Romanovsky , linux-cxl@vger.kernel.org, patches@lists.linux.dev Subject: [PATCH v2 0/8] Introduce fwctl subystem Date: Mon, 24 Jun 2024 19:47:24 -0300 Message-ID: <0-v2-940e479ceba9+3821-fwctl_jgg@nvidia.com> Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Xref: photonic.trudheim.com org.kernel.vger.linux-cxl:29104 org.kernel.vger.netdev:354915 Newsgroups: org.kernel.vger.linux-cxl,dev.linux.lists.patches,org.kernel.vger.linux-doc,org.kernel.vger.linux-rdma,org.kernel.vger.netdev Path: photonic.trudheim.com!nntp.lore.kernel.org!not-for-mail 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. This series comes with mlx5 as a driver implementation, and I have soft commitments for at least three more drivers. There have been two LWN articles written discussing various aspects of this proposal: https://lwn.net/Articles/955001/ https://lwn.net/Articles/969383/ 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/ Enfabrica - https://lore.kernel.org/r/9cc7127f-8674-43bc-b4d7-b1c4c2d96fed@kernel.org/ NVIDIA Networking Oracle Linux - https://lore.kernel.org/r/6lakj6lxlxhdgrewodvj3xh6sxn3d36t5dab6najzyti2navx3@wrge7cyfk6nq 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 v2: - 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 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.rst | 269 ++++++++++++ Documentation/userspace-api/index.rst | 1 + .../userspace-api/ioctl/ioctl-number.rst | 1 + MAINTAINERS | 16 + drivers/Kconfig | 2 + drivers/Makefile | 1 + drivers/fwctl/Kconfig | 23 + drivers/fwctl/Makefile | 5 + drivers/fwctl/main.c | 412 ++++++++++++++++++ drivers/fwctl/mlx5/Makefile | 4 + drivers/fwctl/mlx5/main.c | 337 ++++++++++++++ drivers/net/ethernet/mellanox/mlx5/core/dev.c | 8 + include/linux/fwctl.h | 112 +++++ include/linux/panic.h | 3 +- include/uapi/fwctl/fwctl.h | 137 ++++++ include/uapi/fwctl/mlx5.h | 36 ++ kernel/panic.c | 1 + 18 files changed, 1372 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/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/fwctl.h create mode 100644 include/uapi/fwctl/mlx5.h base-commit: f2661062f16b2de5d7b6a5c42a9a5c96326b8454 -- 2.45.2 . From: alison.schofield@intel.com To: Davidlohr Bueso , Jonathan Cameron , Dave Jiang , Alison Schofield , Vishal Verma , Ira Weiny , Dan Williams Cc: linux-cxl@vger.kernel.org Subject: [PATCH v3 0/4] XOR Math Fixups: translation & position Date: Mon, 24 Jun 2024 17:55:51 -0700 Message-Id: X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Xref: photonic.trudheim.com org.kernel.vger.linux-cxl:29105 Newsgroups: org.kernel.vger.linux-cxl Path: photonic.trudheim.com!nntp.lore.kernel.org!not-for-mail From: Alison Schofield Changes in v3: - Patch 2: Perform the 'chunk' check on Modulo decodes only - Patch 1: Fold cxl_translate() into cxl_dpa_to_hpa() (Jonathan) Jonathan asked for a rename of cxl_translate to cxl_dpa_to_hpa() but the latter already existed and the work of cxl_translate() was minimal. They are now one. - Remove the mention of XOR's purpose in Patch 2 commit log (Dan) - Reword hamming weight wrt XORALLBITS code comment (Jonathan) - Post a unit test upstream[1] (Dan, Jonathan) - Remove Reviewed-by Tags on Patch 1 & 2 due to rework - Add Diego's Tested-by tag to Patch 2,3 Link to v2: https://lore.kernel.org/cover.1714159486.git.alison.schofield@intel.com/ [1] https://lore.kernel.org/20240624210644.495563-1-alison.schofield@intel.com/ Begin cover letter: Rather than repeat the individual patch commit message content, let me describe the flow of this set: Patch 1: Rename an existing fn - cxl_trace_hpa()-> cxl_dpa_to_hpa() A tiny, yet essential cleanup to take first. Patch 2: cxl: Restore XOR'd position bits during address translation The problem fixed in this patch, bad HPA translations with XOR math, came to my attention recently. Patch 3 & Patch 4 are paired. Patch 3 presents the new method for verifying a target position in the list and Patch 4 removes the old method. These could be squashed. FYI - the reason I don't present the code removal first is because I think it is easier to read the diff if I leave in the old root decoder call back setup for calc_hb, insert the new call back along the same path, and then rip out the defunct calc_hb. That's the way I created the patchset and it may be an easier way for reviewers to follow along with the root decoder callback setup. Alison Schofield (4): cxl/core: Rename cxl_trace_hpa() to cxl_dpa_to_hpa() cxl: Restore XOR'd position bits during address translation cxl/region: Verify target positions using the ordered target list cxl: Remove defunct code calculating host bridge target positions drivers/cxl/acpi.c | 80 ++++++++++++++++----------------------- drivers/cxl/core/core.h | 8 ++-- drivers/cxl/core/mbox.c | 2 +- drivers/cxl/core/port.c | 21 ++-------- drivers/cxl/core/region.c | 60 ++++++++++++++--------------- drivers/cxl/core/trace.h | 4 +- drivers/cxl/cxl.h | 10 ++--- 7 files changed, 77 insertions(+), 108 deletions(-) base-commit: f2661062f16b2de5d7b6a5c42a9a5c96326b8454 -- 2.37.3 . From: Jonathan Cameron To: , , , , CC: Subject: [PATCH qemu 0/2] hw/cxl: DCD tweaks and improvements. Date: Tue, 25 Jun 2024 18:08:03 +0100 Message-ID: <20240625170805.359278-1-Jonathan.Cameron@huawei.com> X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain Xref: photonic.trudheim.com org.kernel.vger.linux-cxl:29116 Newsgroups: org.kernel.vger.linux-cxl Path: photonic.trudheim.com!nntp.lore.kernel.org!not-for-mail These came from review after Michael Tsirkin had queued the DCD stuff on his QEMU tree. For reasons unrelated to this series, the pull request was rejected but I'm assuming Michael will send a fresh pull request soon. Hence this is based on top of qemu/master with the DCD patches from gitlab.com/mstredhat/qemu. Markus suggested a number of cleanups for the QMP interface fixing documentation, and capitalization along with making sure we have consistent specification references. He also made the suggestion that at least for now we mark the interfaces as unstable, so I've done that as well. Jonathan Cameron (2): hw/cxl/events: Improve QMP interfaces and documentation for add/release dynamic capacity. hw/cxl/events: Mark cxl-add-dynamic-capacity and cxl-release-dynamic-capcity unstable qapi/cxl.json | 164 +++++++++++++++++++++++++-------------- hw/mem/cxl_type3.c | 18 ++--- hw/mem/cxl_type3_stubs.c | 8 +- 3 files changed, 118 insertions(+), 72 deletions(-) -- 2.43.0 .