5d6a322156
WARN and bail if is_unsync_root() is passed a root for which there is no shadow page, i.e. is passed the physical address of one of the special roots, which do not have an associated shadow page. The current usage squeaks by without bug reports because neither kvm_mmu_sync_roots() nor kvm_mmu_sync_prev_roots() calls the helper with pae_root or pml4_root, and 5-level AMD CPUs are not generally available, i.e. no one can coerce KVM into calling is_unsync_root() on pml5_root. Note, this doesn't fix the mess with 5-level nNPT, it just (hopefully) prevents KVM from crashing. Cc: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220225182248.3812651-8-seanjc@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.