Merge tag 'kvm-x86-mmu-6.4' of https://github.com/kvm-x86/linux into HEAD

Merge tag 'kvm-x86-mmu-6.4' of https://github.com/kvm-x86/linux into HEAD

KVM x86 MMU changes for 6.4:

 - Tweak FNAME(sync_spte) to avoid unnecessary writes+flushes when the
   guest is only adding new PTEs

 - Overhaul .sync_page() and .invlpg() to share the .sync_page()
   implementation, i.e. utilize .sync_page()'s optimizations when emulating
   invalidations

 - Clean up the range-based flushing APIs

 - Revamp the TDP MMU's reaping of Accessed/Dirty bits to clear a single
   A/D bit using a LOCK AND instead of XCHG, and skip all of the "handle
   changed SPTE" overhead associated with writing the entire entry

 - Track the number of "tail" entries in a pte_list_desc to avoid having
   to walk (potentially) all descriptors during insertion and deletion,
   which gets quite expensive if the guest is spamming fork()

 - Misc cleanups