diff mbox series

[v2,4/5] KVM: x86/mmu: Remove handle_changed_spte_dirty_log()

Message ID 20230203192822.106773-5-vipinsh@google.com
State New
Headers
Series Optimize clear dirty log |

Commit Message

Vipin Sharma Feb. 3, 2023, 7:28 p.m. UTC 
  Remove handle_changed_spte_dirty_log() as there is no code flow which
sets leaf SPTE writable and hit this path.

Signed-off-by: Vipin Sharma <vipinsh@google.com>
---
 arch/x86/kvm/mmu/tdp_mmu.c | 22 ----------------------
 1 file changed, 22 deletions(-)

Comments

David Matlack Feb. 6, 2023, 11:59 p.m. UTC | #1 
On Fri, Feb 03, 2023 at 11:28:21AM -0800, Vipin Sharma wrote:
> Remove handle_changed_spte_dirty_log() as there is no code flow which
> sets leaf SPTE writable and hit this path.

Heh, way too vague again. e.g. This needs to explain how make_spte()
marks pages are dirty when constructing new SPTEs for the TDP MMU.
Vipin Sharma Feb. 7, 2023, 5:51 p.m. UTC | #2 
On Mon, Feb 6, 2023 at 3:59 PM David Matlack <dmatlack@google.com> wrote:
>
> On Fri, Feb 03, 2023 at 11:28:21AM -0800, Vipin Sharma wrote:
> > Remove handle_changed_spte_dirty_log() as there is no code flow which
> > sets leaf SPTE writable and hit this path.
>
> Heh, way too vague again. e.g. This needs to explain how make_spte()
> marks pages are dirty when constructing new SPTEs for the TDP MMU.

Okay, I will try to be more detailed in the next version.
diff mbox series

Patch

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 18630a06fa1f..afe0dcb1859e 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -345,24 +345,6 @@  static void handle_changed_spte_acc_track(u64 old_spte, u64 new_spte, int level)
 		kvm_set_pfn_accessed(spte_to_pfn(old_spte));
 }
 
-static void handle_changed_spte_dirty_log(struct kvm *kvm, int as_id, gfn_t gfn,
-					  u64 old_spte, u64 new_spte, int level)
-{
-	bool pfn_changed;
-	struct kvm_memory_slot *slot;
-
-	if (level > PG_LEVEL_4K)
-		return;
-
-	pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte);
-
-	if ((!is_writable_pte(old_spte) || pfn_changed) &&
-	    is_writable_pte(new_spte)) {
-		slot = __gfn_to_memslot(__kvm_memslots(kvm, as_id), gfn);
-		mark_page_dirty_in_slot(kvm, slot, gfn);
-	}
-}
-
 static void tdp_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
 	kvm_account_pgtable_pages((void *)sp->spt, +1);
@@ -614,8 +596,6 @@  static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
 	__handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level,
 			      shared);
 	handle_changed_spte_acc_track(old_spte, new_spte, level);
-	handle_changed_spte_dirty_log(kvm, as_id, gfn, old_spte,
-				      new_spte, level);
 }
 
 /*
@@ -727,8 +707,6 @@  static u64 _tdp_mmu_set_spte(struct kvm *kvm, int as_id, tdp_ptep_t sptep,
 
 	__handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, false);
 	handle_changed_spte_acc_track(old_spte, new_spte, level);
-	handle_changed_spte_dirty_log(kvm, as_id, gfn, old_spte, new_spte,
-				      level);
 	return old_spte;
 }