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This moves the code that loads and unloads the guest SLB values so that it is done while the guest LPCR value is loaded in the LPCR register. The reason for doing this is that on POWER9, the behaviour of the slbmte instruction depends on the LPCR[UPRT] bit. If UPRT is 1, as it is for a radix host (or guest), the SLB index is truncated to 2 bits. This means that for a HPT guest on a radix host, the SLB was not being loaded correctly, causing the guest to crash. The SLB is now loaded much later in the guest entry path, after the LPCR is loaded, which for a secondary thread is after it sees that the primary thread has switched the MMU to the guest. The loop that waits for the primary thread has a branch out to the exit code that is taken if it sees that other threads have commenced exiting the guest. Since we have now not loaded the SLB at this point, we make this path branch to a new label 'guest_bypass' and we move the SLB unload code to before this label. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.