5499ea73e7
Right now, PGD caching avoids placing a PAE root in the cache by using the old value of mmu->root_level and mmu->shadow_root_level; it does not look for a cached PGD if the old root is a PAE one, and then frees it using kvm_mmu_free_roots. Change the logic instead to free the uncacheable root early. This way, __kvm_new_mmu_pgd is able to look up the cache when going from 32-bit to 64-bit (if there is a hit, the invalid root becomes the least recently used). An example of this is nested virtualization with shadow paging, when a 64-bit L1 runs a 32-bit L2. As a side effect (which is actually the reason why this patch was written), PGD caching does not use the old value of mmu->root_level and mmu->shadow_root_level anymore. Reviewed-by: Sean Christopherson <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.