ccadf154cb
The pseries platform can support dynamic secure boot (i.e. secure boot using user-defined keys) using variables contained with the PowerVM LPAR Platform KeyStore (PLPKS). Using the powerpc secvar API, expose the relevant variables for pseries dynamic secure boot through the existing secvar filesystem layout. The relevant variables for dynamic secure boot are signed in the keystore, and can only be modified using the H_PKS_SIGNED_UPDATE hcall. Object labels in the keystore are encoded using ucs2 format. With our fixed variable names we don't have to care about encoding outside of the necessary byte padding. When a user writes to a variable, the first 8 bytes of data must contain the signed update flags as defined by the hypervisor. When a user reads a variable, the first 4 bytes of data contain the policies defined for the object. Limitations exist due to the underlying implementation of sysfs binary attributes, as is the case for the OPAL secvar implementation - partial writes are unsupported and writes cannot be larger than PAGE_SIZE. (Even when using bin_attributes, which can be larger than a single page, sysfs only gives us one page's worth of write buffer at a time, and the hypervisor does not expose an interface for partial writes.) Co-developed-by: Nayna Jain <nayna@linux.ibm.com> Signed-off-by: Nayna Jain <nayna@linux.ibm.com> Co-developed-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com> Signed-off-by: Russell Currey <ruscur@russell.cc> [mpe: Add NLS dependency to fix build errors, squash fix from ajd] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230210080401.345462-25-ajd@linux.ibm.com
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.