3e44dce4d0
So far, the loop bodies already ensure the PTE is present before calling __shadow_walk_next(): Some loop bodies simply exit with a !PRESENT directly and some other loop bodies, i.e. FNAME(fetch) and __direct_map() do not currently guard their walks with is_shadow_present_pte, but only because they install present non-leaf SPTEs in the loop itself. But checking pte present in __shadow_walk_next() (which is called from shadow_walk_okay()) is more prudent; walking past a !PRESENT SPTE would lead to attempting to read a the next level SPTE from a garbage iter->shadow_addr. It also allows to remove the is_shadow_present_pte() checks from the loop bodies. Reviewed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Message-Id: <20210906122547.263316-2-jiangshanlai@gmail.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.