[0/2] RCU related fix based on kvm-coco-queue.

Message

Yan Zhao Nov. 4, 2024, 8:41 a.m. UTC

Hi Paolo and Sean,

The two patches are fixups to RCU related issues reported by sparse.

Patch 1 was reported by kernel test robot related to dereference of
        mirrored sptep.

Patch 2 was a result of running sparse locally with error message:
        "error: incompatible types in comparison expression (different
        address spaces)" in kvm_gmem_get_file() and __kvm_gmem_get_pfn().

        Initially, I wanted to fix it by using rcu_access_pointer() to
        fetch the rcu-protected pointer slot->gmem.file.

        However, after further analysis, I think it's not necessary to
        rely on RCU to protect slot->gmem.file.

Please kindly take a look to see if they are appropriate.

Thanks
Yan


Rick Edgecombe (1):
  KVM: x86/tdp_mmu: Use rcu_dereference() to protect sptep for
    dereferencing

Yan Zhao (1):
  KVM: guest_memfd: Remove RCU-protected attribute from slot->gmem.file

 arch/x86/kvm/mmu/spte.h    |  4 ++--
 arch/x86/kvm/mmu/tdp_mmu.c |  6 +++---
 include/linux/kvm_host.h   |  2 +-
 virt/kvm/guest_memfd.c     | 23 ++++++++++-------------
 4 files changed, 16 insertions(+), 19 deletions(-)


base-commit: 49c492a89914b02fa5011d9ea9848318c6c98dd9