David Matlack
0b873fd7fb
This check is redundant because the root shadow page will only be a TDP MMU page if is_tdp_mmu_enabled() returns true, and is_tdp_mmu_enabled() never changes for the lifetime of a VM. It's possible that this check was added for performance reasons but it is unlikely that it is useful in practice since to_shadow_page() is cheap. That being said, this patch also caches the return value of is_tdp_mmu_root() in direct_page_fault() since there's no reason to duplicate the call so many times, so performance is not a concern. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: David Matlack <dmatlack@google.com> Message-Id: <20210617231948.2591431-3-dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.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.