linux-kernel - [Patch v3 7/7] KVM: x86/mmu: Merge all handle_changed

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Message-ID: <20230211014626.3659152-8-vipinsh@google.com>
Date:   Fri, 10 Feb 2023 17:46:26 -0800
From:   Vipin Sharma <vipinsh@...gle.com>
To:     seanjc@...gle.com, pbonzini@...hat.com, bgardon@...gle.com,
        dmatlack@...gle.com
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Vipin Sharma <vipinsh@...gle.com>
Subject: [Patch v3 7/7] KVM: x86/mmu: Merge all handle_changed_pte* functions.

__handle_changed_pte() and handle_changed_spte_acc_track() are always
used together. Merge these two functions and name the new function
handle_changed_pte(). Remove the existing handle_changed_pte() function
which just calls __handle_changed_pte and
handle_changed_spte_acc_track().

This converges SPTEs change handling code to a single place.

Signed-off-by: Vipin Sharma <vipinsh@...gle.com>
Reviewed-by: Ben Gardon <bgardon@...gle.com>
---
 arch/x86/kvm/mmu/tdp_mmu.c | 42 +++++++++++---------------------------
 1 file changed, 12 insertions(+), 30 deletions(-)

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 0c031319e901..67538ec48ce5 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -334,17 +334,6 @@ static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
 				u64 old_spte, u64 new_spte, int level,
 				bool shared);
 
-static void handle_changed_spte_acc_track(u64 old_spte, u64 new_spte, int level)
-{
-	if (!is_shadow_present_pte(old_spte) || !is_last_spte(old_spte, level))
-		return;
-
-	if (is_accessed_spte(old_spte) &&
-	    (!is_shadow_present_pte(new_spte) || !is_accessed_spte(new_spte) ||
-	     spte_to_pfn(old_spte) != spte_to_pfn(new_spte)))
-		kvm_set_pfn_accessed(spte_to_pfn(old_spte));
-}
-
 static void tdp_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
 	kvm_account_pgtable_pages((void *)sp->spt, +1);
@@ -487,7 +476,7 @@ static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared)
 }
 
 /**
- * __handle_changed_spte - handle bookkeeping associated with an SPTE change
+ * handle_changed_spte - handle bookkeeping associated with an SPTE change
  * @kvm: kvm instance
  * @as_id: the address space of the paging structure the SPTE was a part of
  * @gfn: the base GFN that was mapped by the SPTE
@@ -501,9 +490,9 @@ static void handle_removed_pt(struct kvm *kvm, tdp_ptep_t pt, bool shared)
  * Handle bookkeeping that might result from the modification of a SPTE.
  * This function must be called for all TDP SPTE modifications.
  */
-static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
-				  u64 old_spte, u64 new_spte, int level,
-				  bool shared)
+static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
+				u64 old_spte, u64 new_spte, int level,
+				bool shared)
 {
 	bool was_present = is_shadow_present_pte(old_spte);
 	bool is_present = is_shadow_present_pte(new_spte);
@@ -587,15 +576,10 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
 	if (was_present && !was_leaf &&
 	    (is_leaf || !is_present || WARN_ON_ONCE(pfn_changed)))
 		handle_removed_pt(kvm, spte_to_child_pt(old_spte, level), shared);
-}
 
-static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn,
-				u64 old_spte, u64 new_spte, int level,
-				bool shared)
-{
-	__handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level,
-			      shared);
-	handle_changed_spte_acc_track(old_spte, new_spte, level);
+	if (was_leaf && is_accessed_spte(old_spte) &&
+	    (!is_present || !is_accessed_spte(new_spte) || pfn_changed))
+		kvm_set_pfn_accessed(spte_to_pfn(old_spte));
 }
 
 /*
@@ -638,9 +622,8 @@ static inline int tdp_mmu_set_spte_atomic(struct kvm *kvm,
 	if (!try_cmpxchg64(sptep, &iter->old_spte, new_spte))
 		return -EBUSY;
 
-	__handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,
-			      new_spte, iter->level, true);
-	handle_changed_spte_acc_track(iter->old_spte, new_spte, iter->level);
+	handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte,
+			    new_spte, iter->level, true);
 
 	return 0;
 }
@@ -705,8 +688,7 @@ static u64 tdp_mmu_set_spte(struct kvm *kvm, int as_id, tdp_ptep_t sptep,
 
 	old_spte = kvm_tdp_mmu_write_spte(sptep, old_spte, new_spte, level);
 
-	__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(kvm, as_id, gfn, old_spte, new_spte, level, false);
 	return old_spte;
 }
 
@@ -1276,7 +1258,7 @@ static bool set_spte_gfn(struct kvm *kvm, struct tdp_iter *iter,
 	 * Note, when changing a read-only SPTE, it's not strictly necessary to
 	 * zero the SPTE before setting the new PFN, but doing so preserves the
 	 * invariant that the PFN of a present * leaf SPTE can never change.
-	 * See __handle_changed_spte().
+	 * See handle_changed_spte().
 	 */
 	tdp_mmu_iter_set_spte(kvm, iter, 0);
 
@@ -1301,7 +1283,7 @@ bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
 	/*
 	 * No need to handle the remote TLB flush under RCU protection, the
 	 * target SPTE _must_ be a leaf SPTE, i.e. cannot result in freeing a
-	 * shadow page.  See the WARN on pfn_changed in __handle_changed_spte().
+	 * shadow page. See the WARN on pfn_changed in handle_changed_spte().
 	 */
 	return kvm_tdp_mmu_handle_gfn(kvm, range, set_spte_gfn);
 }
-- 
2.39.1.581.gbfd45094c4-goog