Sean Christopherson
272b0a998d
KVM: nVMX: Don't clobber nested MMU's A/D status on EPTP switch
Drop bogus logic that incorrectly clobbers the accessed/dirty enabling status of the nested MMU on an EPTP switch. When nested EPT is enabled, walk_mmu points at L2's _legacy_ page tables, not L1's EPT for L2. This is likely a benign bug, as mmu->ept_ad is never consumed (since the MMU is not a nested EPT MMU), and stuffing mmu_role.base.ad_disabled will never propagate into future shadow pages since the nested MMU isn't used to map anything, just to walk L2's page tables. Note, KVM also does a full MMU reload, i.e. the guest_mmu will be recreated using the new EPTP, and thus any change in A/D enabling will be properly recognized in the relevant MMU. Fixes: 41ab93727467 ("KVM: nVMX: Emulate EPTP switching for the L1 hypervisor") Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210609234235.1244004-4-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.
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