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commite7d445ab26upstream. When runtime support for converting between 4-level and 5-level pagetables was added to the kernel, the SME code that built pagetables was updated to use the pagetable functions, e.g. p4d_offset(), etc., in order to simplify the code. However, the use of the pagetable functions in early boot code requires the use of the USE_EARLY_PGTABLE_L5 #define in order to ensure that the proper definition of pgtable_l5_enabled() is used. Without the #define, pgtable_l5_enabled() is #defined as cpu_feature_enabled(X86_FEATURE_LA57). In early boot, the CPU features have not yet been discovered and populated, so pgtable_l5_enabled() will return false even when 5-level paging is enabled. This causes the SME code to always build 4-level pagetables to perform the in-place encryption. If 5-level paging is enabled, switching to the SME pagetables results in a page-fault that kills the boot. Adding the #define results in pgtable_l5_enabled() using the __pgtable_l5_enabled variable set in early boot and the SME code building pagetables for the proper paging level. Fixes:aad983913d("x86/mm/encrypt: Simplify sme_populate_pgd() and sme_populate_pgd_large()") Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: <stable@vger.kernel.org> # 4.18.x Link: https://lkml.kernel.org/r/2cb8329655f5c753905812d951e212022a480475.1634318656.git.thomas.lendacky@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.