This is mostly the first half of a series by Yan to optimize KVM's handling of guest MTRR changes for VMs with non-coherent DMA. Yan had to put more complex changes that actually realize the optimizations on hold, but the patches here are all nice cleanups on their own. The following changes since commit 5804c19b80bf625c6a9925317f845e497434d6d3: Merge tag 'kvm-riscv-fixes-6.6-1' of https://github.com/kvm-riscv/linux into HEAD (2023-09-23 05:35:55 -0400) are available in the Git repository at: https://github.com/kvm-x86/linux.git tags/kvm-x86-mmu-6.7 for you to fetch changes up to 1de9992f9de0a92b6e11133aba0e2be833c11084: KVM: x86/mmu: Remove unnecessary ‘NULL’ values from sptep (2023-10-18 14:34:28 -0700) ---------------------------------------------------------------- KVM x86 MMU changes for 6.7: - Clean up code that deals with honoring guest MTRRs when the VM has non-coherent DMA and host MTRRs are ignored, i.e. EPT is enabled. - Zap EPT entries when non-coherent DMA assignment stops/start to prevent using stale entries with the wrong memtype. - Don't ignore guest PAT for CR0.CD=1 && KVM_X86_QUIRK_CD_NW_CLEARED=y, as there's zero reason to ignore guest PAT if the effective MTRR memtype is WB. This will also allow for future optimizations of handling guest MTRR updates for VMs with non-coherent DMA and the quirk enabled. - Harden the fast page fault path to guard against encountering an invalid root when walking SPTEs. ---------------------------------------------------------------- Li zeming (1): KVM: x86/mmu: Remove unnecessary ‘NULL’ values from sptep Yan Zhao (5): KVM: x86/mmu: Add helpers to return if KVM honors guest MTRRs KVM: x86/mmu: Zap SPTEs when CR0.CD is toggled iff guest MTRRs are honored KVM: x86/mmu: Zap SPTEs on MTRR update iff guest MTRRs are honored KVM: x86/mmu: Zap KVM TDP when noncoherent DMA assignment starts/stops KVM: VMX: drop IPAT in memtype when CD=1 for KVM_X86_QUIRK_CD_NW_CLEARED arch/x86/kvm/mmu.h | 7 +++++++ arch/x86/kvm/mmu/mmu.c | 37 ++++++++++++++++++++++++++----------- arch/x86/kvm/mtrr.c | 2 +- arch/x86/kvm/vmx/vmx.c | 9 +++------ arch/x86/kvm/x86.c | 21 ++++++++++++++++++--- 5 files changed, 55 insertions(+), 21 deletions(-)
