On Fri, 02 Feb 2024 16:23:39 -0800, Sean Christopherson wrote: > Resurrect a 6 month old patch from Mingwei, add a few cleanps on top, and > fix a largely theoretical race between emulating writes and write-protecting > shadow pages. At least, I'm pretty sure there's a race. Memory ordering > isn't exactly my strong suit. > > v2: > - Drop the unnecessary READ_ONCE(). [Jim] > - Cleanup more old crud in reexecute_instruction(). > - Fix the aforementioned race. > > [...] Applied 1-3 to kvm-x86 mmu. I will likely apply patch 4 for 6.9 as well, but assuming it doesn't get attention "soon", I'll apply it dead last in kvm-x86/mmu so that it's easy to discard if my paranoia is unfounded. [1/4] KVM: x86/mmu: Don't acquire mmu_lock when using indirect_shadow_pages as a heuristic https://github.com/kvm-x86/linux/commit/474b99ed703b [2/4] KVM: x86: Drop dedicated logic for direct MMUs in reexecute_instruction() https://github.com/kvm-x86/linux/commit/515c18a64e70 [3/4] KVM: x86: Drop superfluous check on direct MMU vs. WRITE_PF_TO_SP flag https://github.com/kvm-x86/linux/commit/dfeef3d3f310 [4/4] KVM: x86/mmu: Fix a *very* theoretical race in kvm_mmu_track_write() (not applied, yet) -- https://github.com/kvm-x86/linux/tree/next