Aside from the A/D overhaul that you've already seen, the two highlights are support for recovering TDP MMU huge pages in-place, and removal of KVM's MMU shrinker (which IMO is long overdue). The following changes since commit 5cb1659f412041e4780f2e8ee49b2e03728a2ba6: Merge branch 'kvm-no-struct-page' into HEAD (2024-10-25 13:38:16 -0400) are available in the Git repository at: https://github.com/kvm-x86/linux.git tags/kvm-x86-mmu-6.13 for you to fetch changes up to 4cf20d42543cff8778f70b0c29def984098641a5: KVM: x86/mmu: Drop per-VM zapped_obsolete_pages list (2024-11-04 19:22:53 -0800) ---------------------------------------------------------------- KVM x86 MMU changes for 6.13 - Cleanup KVM's handling of Accessed and Dirty bits to dedup code, improve documentation, harden against unexpected changes, and to simplify A/D-disabled MMUs by using the hardware-defined A/D bits to track if a PFN is Accessed and/or Dirty. - Elide TLB flushes when aging SPTEs, as has been done in x86's primary MMU for over 10 years. - Batch TLB flushes when zapping collapsible TDP MMU SPTEs, i.e. when dirty logging is toggled off, which reduces the time it takes to disable dirty logging by ~3x. - Recover huge pages in-place in the TDP MMU instead of zapping the SP and waiting until the page is re-accessed to create a huge mapping. Proactively installing huge pages can reduce vCPU jitter in extreme scenarios. - Remove support for (poorly) reclaiming page tables in shadow MMUs via the primary MMU's shrinker interface. ---------------------------------------------------------------- David Matlack (5): KVM: x86/mmu: Drop @max_level from kvm_mmu_max_mapping_level() KVM: x86/mmu: Batch TLB flushes when zapping collapsible TDP MMU SPTEs KVM: x86/mmu: Recover TDP MMU huge page mappings in-place instead of zapping KVM: x86/mmu: Rename make_huge_page_split_spte() to make_small_spte() KVM: x86/mmu: WARN if huge page recovery triggered during dirty logging Sean Christopherson (21): KVM: x86/mmu: Flush remote TLBs iff MMU-writable flag is cleared from RO SPTE KVM: x86/mmu: Always set SPTE's dirty bit if it's created as writable KVM: x86/mmu: Fold all of make_spte()'s writable handling into one if-else KVM: x86/mmu: Don't force flush if SPTE update clears Accessed bit KVM: x86/mmu: Don't flush TLBs when clearing Dirty bit in shadow MMU KVM: x86/mmu: Drop ignored return value from kvm_tdp_mmu_clear_dirty_slot() KVM: x86/mmu: Fold mmu_spte_update_no_track() into mmu_spte_update() KVM: x86/mmu: WARN and flush if resolving a TDP MMU fault clears MMU-writable KVM: x86/mmu: Add a dedicated flag to track if A/D bits are globally enabled KVM: x86/mmu: Set shadow_accessed_mask for EPT even if A/D bits disabled KVM: x86/mmu: Set shadow_dirty_mask for EPT even if A/D bits disabled KVM: x86/mmu: Use Accessed bit even when _hardware_ A/D bits are disabled KVM: x86/mmu: Process only valid TDP MMU roots when aging a gfn range KVM: x86/mmu: Stop processing TDP MMU roots for test_age if young SPTE found KVM: x86/mmu: Dedup logic for detecting TLB flushes on leaf SPTE changes KVM: x86/mmu: Set Dirty bit for new SPTEs, even if _hardware_ A/D bits are disabled KVM: Allow arch code to elide TLB flushes when aging a young page KVM: x86: Don't emit TLB flushes when aging SPTEs for mmu_notifiers KVM: x86/mmu: Check yielded_gfn for forward progress iff resched is needed KVM: x86/mmu: Demote the WARN on yielded in xxx_cond_resched() to KVM_MMU_WARN_ON KVM: x86/mmu: Refactor TDP MMU iter need resched check Vipin Sharma (2): KVM: x86/mmu: Remove KVM's MMU shrinker KVM: x86/mmu: Drop per-VM zapped_obsolete_pages list arch/x86/include/asm/kvm_host.h | 5 +- arch/x86/kvm/Kconfig | 1 + arch/x86/kvm/mmu/mmu.c | 201 ++++++------------------------- arch/x86/kvm/mmu/mmu_internal.h | 3 +- arch/x86/kvm/mmu/spte.c | 99 +++++++++------- arch/x86/kvm/mmu/spte.h | 76 ++++++------ arch/x86/kvm/mmu/tdp_mmu.c | 257 +++++++++++++++++++--------------------- arch/x86/kvm/mmu/tdp_mmu.h | 6 +- arch/x86/kvm/x86.c | 18 ++- virt/kvm/Kconfig | 4 + virt/kvm/kvm_main.c | 20 +--- 11 files changed, 280 insertions(+), 410 deletions(-)
