[PATCH 0/4] Fix RCU warnings in TDP MMU

[Ben Gardon]

The Linux Test Robot found a few RCU warnings in the TDP MMU:
https://www.spinics.net/lists/kernel/msg3845500.html
https://www.spinics.net/lists/kernel/msg3845521.html

Fix these warnings and cleanup a hack in tdp_mmu_iter_cond_resched.

Tested by compiling as suggested in the test robot report and confirmed that
the warnings go away with this series applied. Also ran kvm-unit-tests on an
Intel Skylake machine with the TDP MMU enabled and confirmed that the series
introduced no new failures.

Ben Gardon (4):
  KVM: x86/mmu: Fix RCU usage in handle_removed_tdp_mmu_page
  KVM: x86/mmu: Fix RCU usage for tdp_iter_root_pt
  KVM: x86/mmu: Fix RCU usage when atomically zapping SPTEs
  KVM: x86/mmu: Factor out tdp_iter_return_to_root

 arch/x86/kvm/mmu/tdp_iter.c | 34 +++++++++++++++++++++++++---------
 arch/x86/kvm/mmu/tdp_iter.h |  3 ++-
 arch/x86/kvm/mmu/tdp_mmu.c  | 19 +++++++++++--------
 3 files changed, 38 insertions(+), 18 deletions(-)

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2.31.0.rc2.261.g7f71774620-goog