This series is spun off from Sean's suggestions on [PATCH 1/8] of my TDP MMU Fast Page Fault series [1]. Patches 1-2 and 4 cleans up some redundant code in the page fault handling path: - Redundant checks for TDP MMU enablement. - Redundant checks for root_hpa validity. Patch 3 refactors is_tdp_mmu_root into a simpler function prototype. Note to reviewers: I purposely opted not to remove the root_hpa check from is_tdp_mmu even though it is theoretically redundant in the current code. My rational is that it could be called from outside the page fault handling code in the future where root_hpa can be invalid. This seems more likely to happen than with the other functions since is_tdp_mmu() is not inherently tied to page fault handling. The cost of getting this wrong is high since the result would be we end up calling executing pfn_to_page(-1 >> PAGE_SHIFT)->private in to_shadow_page. A better solution might be to move the VALID_PAGE check into to_shadow_page but I did not want to expand the scope of this series. To test this series I ran all kvm-unit-tests and KVM selftests on an Intel Cascade Lake machine. [1] https://lore.kernel.org/kvm/YMepDK40DLkD4DSy@xxxxxxxxxx/ David Matlack (4): KVM: x86/mmu: Remove redundant is_tdp_mmu_root check KVM: x86/mmu: Remove redundant is_tdp_mmu_enabled check KVM: x86/mmu: Refactor is_tdp_mmu_root into is_tdp_mmu KVM: x86/mmu: Remove redundant root_hpa checks arch/x86/kvm/mmu/mmu.c | 19 ++++++------------- arch/x86/kvm/mmu/tdp_mmu.c | 5 ----- arch/x86/kvm/mmu/tdp_mmu.h | 5 ++--- 3 files changed, 8 insertions(+), 21 deletions(-) -- 2.32.0.288.g62a8d224e6-goog
