[PATCH v5 0/7] FPGA Security Manager Class Driver

Russ Weight
2020-10-21T00:17:02Z

The FPGA Security Manager class driver provides a common
API for user-space tools to manage updates for secure FPGA
devices. Device drivers that instantiate the FPGA Security
Manager class driver will interact with a HW secure update
engine in order to transfer new FPGA and BMC images to FLASH so
that they will be automatically loaded when the FPGA card reboots.

A significant difference between the FPGA Manager and the FPGA
Security Manager is that the FPGA Manager does a live update (Partial
Reconfiguration) to a device whereas the FPGA Security Manager
updates the FLASH images for the Static Region and the BMC so that
they will be loaded the next time the FPGA card boots. Security is
enforced by hardware and firmware. The security manager interacts
with the firmware to initiate an update, pass in the necessary data,
and collect status on the update.

The n3000bmc-secure driver is the first driver to use the FPGA
Security Manager. This driver was previously submitted in the same
patch set, but has been split out into a separate patch set starting
with V2. Future devices will also make use of this common API for
secure updates.

In addition to managing secure updates of the FPGA and BMC images,
the FPGA Security Manager update process may also be used to
program root entry hashes and cancellation keys for the FPGA static
region, the FPGA partial reconfiguration region, and the BMC.

Secure updates make use of the request_firmware framework, which
requires that image files are accessible under /lib/firmware. A request
for a secure update returns immediately, while the update itself
proceeds in the context of a kernel worker thread. Sysfs files provide
a means for monitoring the progress of a secure update and for
retrieving error information in the event of a failure.

The API consists of sysfs nodes and supports the following functions:

(1) Instantiate and monitor a secure update
(2) Display security information including: Root Entry Hashes (REH),
Cancelled Code Signing Keys (CSK), and flash update counts for
both BMC and FPGA images.

Changelog v4 -> v5:
- Added the devm_fpga_sec_mgr_unregister() function, following recent
changes to the fpga_manager() implementation.
- Changed most of the *_show() functions to use sysfs_emit()
instead of sprintf(
- When checking the return values for functions of type enum
fpga_sec_err err_code, test for FPGA_SEC_ERR_NONE instead of 0

Changelog v3 -> v4:
- This driver is generic enough that it could be used for non Intel
FPGA devices. Changed from "Intel FPGA Security Manager" to FPGA
Security Manager" and removed unnecessary references to "Intel".
- Changed: iops -> sops, imgr -> smgr, IFPGA_ -> FPGA_, ifpga_ to fpga_
Note that this also affects some filenames.

Changelog v2 -> v3:
- Use dev_err() to report invalid progress in sec_progress()
- Use dev_err() to report invalid error code in sec_error()
- Modified sysfs handler check in check_sysfs_handler() to make
it more readable.
- Removed unnecessary "goto done"
- Added a comment to explain imgr->driver_unload in
ifpga_sec_mgr_unregister()

Changelog v1 -> v2:
- Separated out the MAX10 BMC Security Engine to be submitted in
a separate patch-set.
- Bumped documentation dates and versions
- Split ifpga_sec_mgr_register() into create() and register() functions
- Added devm_ifpga_sec_mgr_create()
- Added Documentation/fpga/ifpga-sec-mgr.rst
- Changed progress state "read_file" to "reading"
- Added sec_error() function (similar to sec_progress())
- Removed references to bmc_flash_count & smbus_flash_count (not supported)
- Removed typedefs for imgr ops
- Removed explicit value assignments in enums
- Other minor code cleanup per review comments

Russ Weight (7):
fpga: sec-mgr: intel fpga security manager class driver
fpga: sec-mgr: enable secure updates
fpga: sec-mgr: expose sec-mgr update status
fpga: sec-mgr: expose sec-mgr update errors
fpga: sec-mgr: expose sec-mgr update size
fpga: sec-mgr: enable cancel of secure update
fpga: sec-mgr: expose hardware error info

.../ABI/testing/sysfs-class-fpga-sec-mgr | 143 +++
Documentation/fpga/fpga-sec-mgr.rst | 50 ++
Documentation/fpga/index.rst | 1 +
MAINTAINERS | 9 +
drivers/fpga/Kconfig | 9 +
drivers/fpga/Makefile | 3 +
drivers/fpga/fpga-sec-mgr.c | 843 ++++++++++++++++++
include/linux/fpga/fpga-sec-mgr.h | 139 +++
8 files changed, 1197 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-class-fpga-sec-mgr
create mode 100644 Documentation/fpga/fpga-sec-mgr.rst
create mode 100644 drivers/fpga/fpga-sec-mgr.c
create mode 100644 include/linux/fpga/fpga-sec-mgr.h

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2.25.1