[v2,0/4] Fix RCU warnings in TDP MMU

Message

Ben Gardon March 15, 2021, 6:26 p.m. UTC

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 when atomically zapping SPTEs
  KVM: x86/mmu: Factor out tdp_iter_return_to_root
  KVM: x86/mmu: Store the address space ID in the TDP iterator

 arch/x86/kvm/mmu/mmu_internal.h |  5 +++++
 arch/x86/kvm/mmu/tdp_iter.c     | 30 +++++++++++++++----------
 arch/x86/kvm/mmu/tdp_iter.h     |  4 +++-
 arch/x86/kvm/mmu/tdp_mmu.c      | 40 +++++++++++++--------------------
 4 files changed, 41 insertions(+), 38 deletions(-)