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d2a3ef44c2
Marking the page tableas pinned without ever actually pinning is was probably an oversight in the first place. The main reason for the change is more subtle, though: The write of the one present entry each here and in the subsequently allocated L2 table engage a code path in the hypervisor which exists only for thought-to-be-broken guests: An mmu- update operation to a page which is neither a page table nor marked writable. The hypervisor merely assumes (or should I say "hopes") that the fact that a writable reference to the page can be obtained means it is okay to actually write to that page in response to such a hypercall. While there make all involved code and data dependent upon X86_VSYSCALL_EMULATION (some code was already). Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/1048f5b8-b726-dcc1-1216-9d5ac328ce82@suse.com Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.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.