From b1a8d2b02b69c7d7685f2e19f32034065310dbae Mon Sep 17 00:00:00 2001 From: David Matlack Date: Fri, 15 Mar 2024 16:05:40 -0700 Subject: KVM: x86/mmu: Fix and clarify comments about clearing D-bit vs. write-protecting Drop the "If AD bits are enabled/disabled" verbiage from the comments above kvm_tdp_mmu_clear_dirty_{slot,pt_masked}() since TDP MMU SPTEs may need to be write-protected even when A/D bits are enabled. i.e. These comments aren't technically correct. No functional change intended. Signed-off-by: David Matlack Link: https://lore.kernel.org/r/20240315230541.1635322-4-dmatlack@google.com Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/tdp_mmu.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) (limited to 'arch') diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 23759b2bca5e..04c1f0957fea 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -1594,11 +1594,9 @@ retry: } /* - * Clear the dirty status of all the SPTEs mapping GFNs in the memslot. If - * AD bits are enabled, this will involve clearing the dirty bit on each SPTE. - * If AD bits are not enabled, this will require clearing the writable bit on - * each SPTE. Returns true if an SPTE has been changed and the TLBs need to - * be flushed. + * Clear the dirty status (D-bit or W-bit) of all the SPTEs mapping GFNs in the + * memslot. Returns true if an SPTE has been changed and the TLBs need to be + * flushed. */ bool kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm, const struct kvm_memory_slot *slot) @@ -1656,11 +1654,9 @@ static void clear_dirty_pt_masked(struct kvm *kvm, struct kvm_mmu_page *root, } /* - * Clears the dirty status of all the 4k SPTEs mapping GFNs for which a bit is - * set in mask, starting at gfn. The given memslot is expected to contain all - * the GFNs represented by set bits in the mask. If AD bits are enabled, - * clearing the dirty status will involve clearing the dirty bit on each SPTE - * or, if AD bits are not enabled, clearing the writable bit on each SPTE. + * Clear the dirty status (D-bit or W-bit) of all the 4k SPTEs mapping GFNs for + * which a bit is set in mask, starting at gfn. The given memslot is expected to + * contain all the GFNs represented by set bits in the mask. */ void kvm_tdp_mmu_clear_dirty_pt_masked(struct kvm *kvm, struct kvm_memory_slot *slot, -- cgit v1.2.3