crypto: qat - add anti-rollback support for GEN6 devices

Anti-Rollback (ARB) is a QAT GEN6 hardware feature that prevents loading
firmware with a Security Version Number (SVN) lower than an authorized
minimum. This protects against downgrade attacks by ensuring that only
firmware at or above a committed SVN can run on the acceleration device.

During firmware loading, the driver checks the SVN validation status via
a hardware CSR. If the check reports a failure, firmware authentication
is aborted. If it reports a retry status, the driver reissues the
authentication command up to a maximum number of retries.

Extend the firmware admin interface with two new messages,
ICP_QAT_FW_SVN_READ and ICP_QAT_FW_SVN_COMMIT, to query and commit the
SVN, respectively. Integrate the SVN check into the firmware
authentication path in qat_uclo.c so the driver can react to
anti-rollback status during device bring-up.

Expose SVN information to userspace via a new sysfs attribute group,
qat_svn, under the PCI device directory. The group provides read-only
attributes for the active, enforced minimum, and permanent minimum SVN
values, as well as a write-only commit attribute that allows a system
administrator to commit the currently active SVN as the new authorized
minimum.

This is based on earlier work by Ciunas Bennett.

Signed-off-by: Suman Kumar Chakraborty <suman.kumar.chakraborty@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 114 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-driver-qat_svn b/Documentation/ABI/testing/sysfs-driver-qat_svn
new file mode 100644
index 000000000000..3832b523dcb0
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-qat_svn
@@ -0,0 +1,114 @@
+What:		/sys/bus/pci/devices/<BDF>/qat_svn/
+Date:		June 2026
+KernelVersion:	7.1
+Contact:	qat-linux@intel.com
+Description:	Directory containing Security Version Number (SVN) attributes for
+		the Anti-Rollback (ARB) feature. The ARB feature prevents downloading
+		older firmware versions to the acceleration device.
+
+What:		/sys/bus/pci/devices/<BDF>/qat_svn/enforced_min
+Date:		June 2026
+KernelVersion:	7.1
+Contact:	qat-linux@intel.com
+Description:
+		(RO) Reports the minimum allowed firmware SVN.
+
+		Returns an integer greater than zero. Firmware with SVN lower than
+		this value is rejected.
+
+		A write to qat_svn/commit will update this value. The update is not
+		persistent across reboot; on reboot, this value is reset from
+		qat_svn/permanent_min.
+
+		Example usage::
+
+			# cat /sys/bus/pci/devices/<BDF>/qat_svn/enforced_min
+			2
+
+		This attribute is available only on devices that support
+		Anti-Rollback.
+
+What:		/sys/bus/pci/devices/<BDF>/qat_svn/permanent_min
+Date:		June 2026
+KernelVersion:	7.1
+Contact:	qat-linux@intel.com
+Description:
+		(RO) Reports the persistent minimum SVN used to initialize
+		qat_svn/enforced_min on each reboot.
+
+		Returns an integer greater than zero. A write to qat_svn/commit
+		may update this value, depending on platform/BIOS settings.
+
+		Example usage::
+
+			# cat /sys/bus/pci/devices/<BDF>/qat_svn/permanent_min
+			3
+
+		This attribute is available only on devices that support
+		Anti-Rollback.
+
+What:		/sys/bus/pci/devices/<BDF>/qat_svn/active
+Date:		June 2026
+KernelVersion:	7.1
+Contact:	qat-linux@intel.com
+Description:
+		(RO) Reports the SVN of the currently active firmware image.
+
+		Returns an integer greater than zero.
+
+		Example usage::
+
+			# cat /sys/bus/pci/devices/<BDF>/qat_svn/active
+			2
+
+		This attribute is available only on devices that support
+		Anti-Rollback.
+
+What:		/sys/bus/pci/devices/<BDF>/qat_svn/commit
+Date:		June 2026
+KernelVersion:	7.1
+Contact:	qat-linux@intel.com
+Description:
+		(WO) Commits the currently active SVN as the minimum allowed SVN.
+
+		Writing 1 sets qat_svn/enforced_min to the value of qat_svn/active,
+		preventing future firmware loads with lower SVN.
+
+		Depending on platform/BIOS settings, a commit may also update
+		qat_svn/permanent_min.
+
+		Note that on reboot, qat_svn/enforced_min reverts to
+		qat_svn/permanent_min.
+
+		It is advisable to use this attribute with caution, only when
+		it is necessary to set a new minimum SVN for the firmware.
+
+		Before committing the SVN update, it is crucial to check the
+		current values of qat_svn/active, qat_svn/enforced_min and
+		qat_svn/permanent_min. This verification helps ensure that the
+		commit operation aligns with the intended outcome.
+
+		While writing to the file, any value other than '1' will result
+		in an error and have no effect.
+
+		Example usage::
+
+			## Read current values
+			# cat /sys/bus/pci/devices/<BDF>/qat_svn/enforced_min
+			2
+			# cat /sys/bus/pci/devices/<BDF>/qat_svn/permanent_min
+			2
+			# cat /sys/bus/pci/devices/<BDF>/qat_svn/active
+			3
+
+			## Commit active SVN
+			# echo 1 > /sys/bus/pci/devices/<BDF>/qat_svn/commit
+
+			## Read updated values
+			# cat /sys/bus/pci/devices/<BDF>/qat_svn/enforced_min
+			3
+			# cat /sys/bus/pci/devices/<BDF>/qat_svn/permanent_min
+			3
+
+		This attribute is available only on devices that support
+		Anti-Rollback.