[PATCH 00/17] TDX MMU refactors

Rick Edgecombe
2026-03-27T20:14:27Z

Hi,

This is all the MMU refactors extracted from the discussion on Sean’s
DPAMT/Huge page combined series [0]. I was thinking that since they are
valid cleanups in their own way, we could maybe get them upstream ahead of
time. Yan and I rebased DPAMT/huge pages on this series and made sure it
all still fits together.

It’s not suggested for merging yet. We should go over it again for a more
thorough bug check with everything put together. Sean/Paolo please feel
free to ignore for now, except to maybe comment if you have any objections
to merging it earlier as a cleanup series.

Changes from on-list discussion:
- Go back to free_external_spt() name. Since free_external_sp() was
dropped from the changes there was no similarly named function to
confuse.
- Suggestions around dropping or moving KVM_BUG_ON/WARNs turned into
patches.

Another possible point of discussion:
- Is the last patch needed and does it fit in to a general
refactor/cleanup? (Yan)

Since some of the patches were created from diffs posted by Sean without
SOB, I left them not signed off for now.

Based on kvm-x86-next-2026.03.13, testing was our usual CI suite. AI
review is pending. We'll work through any Sashiko feedback on the list.

Thanks,
Rick

[0] https://lore.kernel.org/kvm/20260129011517.3545883-1-seanjc@google.com/

Rick Edgecombe (4):
KVM: x86/tdp_mmu: Drop zapping KVM_BUG_ON()
set_external_spte_present()
KVM: x86/tdp_mmu: Morph the !is_frozen_spte() check into a
KVM_MMU_WARN_ON()
KVM: TDX: Move set_external_spte_present() assert into TDX code
KVM: x86/mmu: Remove KVM_BUG_ON() that checks lock when removing PTs

Sean Christopherson (13):
x86/tdx: Use pg_level in TDX APIs, not the TDX-Module's 0-based level
KVM: x86/mmu: Update iter->old_spte if cmpxchg64 on mirror SPTE
"fails"
KVM: TDX: Account all non-transient page allocations for per-TD
structures
KVM: x86: Make "external SPTE" ops that can fail RET0 static calls
KVM: x86/tdp_mmu: Centralize updates to present external PTEs
KVM: TDX: Drop kvm_x86_ops.link_external_spt(), use
.set_external_spte() for all
KVM: TDX: Add helper to handle mapping leaf SPTE into S-EPT
KVM: x86/mmu: Fold set_external_spte_present() into its sole caller
KVM: x86/mmu: Plumb the old_spte into kvm_x86_ops.set_external_spte()
KVM: TDX: Hoist tdx_sept_remove_private_spte() above
set_private_spte()
KVM: TDX: Handle removal of leaf SPTEs in .set_private_spte()
KVM: x86: Move error handling inside free_external_spt()
KVM: TDX: Move external page table freeing to TDX code

arch/x86/include/asm/kvm-x86-ops.h | 4 +-
arch/x86/include/asm/kvm_host.h | 13 +-
arch/x86/include/asm/tdx.h | 14 +-
arch/x86/kvm/mmu/tdp_mmu.c | 253 ++++++++++++-----------------
arch/x86/kvm/vmx/tdx.c | 147 ++++++++++-------
arch/x86/virt/vmx/tdx/tdx.c | 26 ++-
6 files changed, 219 insertions(+), 238 deletions(-)

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2.53.0