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| -rw-r--r-- | Documentation/ABI/testing/sysfs-secvar | 119 |
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diff --git a/Documentation/ABI/testing/sysfs-secvar b/Documentation/ABI/testing/sysfs-secvar new file mode 100644 index 0000000000..857cf12b09 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-secvar @@ -0,0 +1,119 @@ +What: /sys/firmware/secvar +Date: August 2019 +Contact: Nayna Jain <nayna@linux.ibm.com> +Description: This directory is created if the POWER firmware supports OS + secureboot, thereby secure variables. It exposes interface + for reading/writing the secure variables + +What: /sys/firmware/secvar/vars +Date: August 2019 +Contact: Nayna Jain <nayna@linux.ibm.com> +Description: This directory lists all the secure variables that are supported + by the firmware. + +What: /sys/firmware/secvar/format +Date: August 2019 +Contact: Nayna Jain <nayna@linux.ibm.com> +Description: A string indicating which backend is in use by the firmware. + This determines the format of the variable and the accepted + format of variable updates. + + On powernv/OPAL, this value is provided by the OPAL firmware + and is expected to be "ibm,edk2-compat-v1". + + On pseries/PLPKS, this is generated by the kernel based on the + version number in the SB_VERSION variable in the keystore, and + has the form "ibm,plpks-sb-v<version>", or + "ibm,plpks-sb-unknown" if there is no SB_VERSION variable. + +What: /sys/firmware/secvar/vars/<variable name> +Date: August 2019 +Contact: Nayna Jain <nayna@linux.ibm.com> +Description: Each secure variable is represented as a directory named as + <variable_name>. The variable name is unique and is in ASCII + representation. The data and size can be determined by reading + their respective attribute files. + +What: /sys/firmware/secvar/vars/<variable_name>/size +Date: August 2019 +Contact: Nayna Jain <nayna@linux.ibm.com> +Description: An integer representation of the size of the content of the + variable. In other words, it represents the size of the data. + +What: /sys/firmware/secvar/vars/<variable_name>/data +Date: August 2019 +Contact: Nayna Jain <nayna@linux.ibm.com> +Description: A read-only file containing the value of the variable. The size + of the file represents the maximum size of the variable data. + +What: /sys/firmware/secvar/vars/<variable_name>/update +Date: August 2019 +Contact: Nayna Jain <nayna@linux.ibm.com> +Description: A write-only file that is used to submit the new value for the + variable. The size of the file represents the maximum size of + the variable data that can be written. + +What: /sys/firmware/secvar/config +Date: February 2023 +Contact: Nayna Jain <nayna@linux.ibm.com> +Description: This optional directory contains read-only config attributes as + defined by the secure variable implementation. All data is in + ASCII format. The directory is only created if the backing + implementation provides variables to populate it, which at + present is only PLPKS on the pseries platform. + +What: /sys/firmware/secvar/config/version +Date: February 2023 +Contact: Nayna Jain <nayna@linux.ibm.com> +Description: Config version as reported by the hypervisor in ASCII decimal + format. + + Currently only provided by PLPKS on the pseries platform. + +What: /sys/firmware/secvar/config/max_object_size +Date: February 2023 +Contact: Nayna Jain <nayna@linux.ibm.com> +Description: Maximum allowed size of objects in the keystore in bytes, + represented in ASCII decimal format. + + This is not necessarily the same as the max size that can be + written to an update file as writes can contain more than + object data, you should use the size of the update file for + that purpose. + + Currently only provided by PLPKS on the pseries platform. + +What: /sys/firmware/secvar/config/total_size +Date: February 2023 +Contact: Nayna Jain <nayna@linux.ibm.com> +Description: Total size of the PLPKS in bytes, represented in ASCII decimal + format. + + Currently only provided by PLPKS on the pseries platform. + +What: /sys/firmware/secvar/config/used_space +Date: February 2023 +Contact: Nayna Jain <nayna@linux.ibm.com> +Description: Current space consumed by the key store, in bytes, represented + in ASCII decimal format. + + Currently only provided by PLPKS on the pseries platform. + +What: /sys/firmware/secvar/config/supported_policies +Date: February 2023 +Contact: Nayna Jain <nayna@linux.ibm.com> +Description: Bitmask of supported policy flags by the hypervisor, + represented as an 8 byte hexadecimal ASCII string. Consult the + hypervisor documentation for what these flags are. + + Currently only provided by PLPKS on the pseries platform. + +What: /sys/firmware/secvar/config/signed_update_algorithms +Date: February 2023 +Contact: Nayna Jain <nayna@linux.ibm.com> +Description: Bitmask of flags indicating which algorithms the hypervisor + supports for signed update of objects, represented as a 16 byte + hexadecimal ASCII string. Consult the hypervisor documentation + for what these flags mean. + + Currently only provided by PLPKS on the pseries platform. |