cdf811a937
commit 2673dfb591a359c75080dd5af3da484b89320d22 upstream. Check kvm_mmu_page_ad_need_write_protect() when deciding whether to write-protect or clear D-bits on TDP MMU SPTEs, so that the TDP MMU accounts for any role-specific reasons for disabling D-bit dirty logging. Specifically, TDP MMU SPTEs must be write-protected when the TDP MMU is being used to run an L2 (i.e. L1 has disabled EPT) and PML is enabled. KVM always disables PML when running L2, even when L1 and L2 GPAs are in the some domain, so failing to write-protect TDP MMU SPTEs will cause writes made by L2 to not be reflected in the dirty log. Reported-by: syzbot+900d58a45dcaab9e4821@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=900d58a45dcaab9e4821 Fixes: 5982a5392663 ("KVM: x86/mmu: Use kvm_ad_enabled() to determine if TDP MMU SPTEs need wrprot") Cc: stable@vger.kernel.org Cc: Vipin Sharma <vipinsh@google.com> Cc: Sean Christopherson <seanjc@google.com> Signed-off-by: David Matlack <dmatlack@google.com> Link: https://lore.kernel.org/r/20240315230541.1635322-2-dmatlack@google.com [sean: massage shortlog and changelog, tweak ternary op formatting] Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.