linux-kernel - [PATCH 06/18] KVM: x86/mmu: Drop ignored return value from kvm_tdp_mmu_clear_dirty

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Message-ID: <20241011021051.1557902-7-seanjc@google.com>
Date: Thu, 10 Oct 2024 19:10:38 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Yan Zhao <yan.y.zhao@...el.com>, Sagi Shahar <sagis@...gle.com>, 
	"Alex Bennée" <alex.bennee@...aro.org>, David Matlack <dmatlack@...gle.com>, 
	James Houghton <jthoughton@...gle.com>
Subject: [PATCH 06/18] KVM: x86/mmu: Drop ignored return value from kvm_tdp_mmu_clear_dirty_slot()

Drop the return value from kvm_tdp_mmu_clear_dirty_slot() as its sole
caller ignores the result (KVM flushes after clearing dirty logs based on
the logs themselves, not based on SPTEs).

Cc: David Matlack <dmatlack@...gle.com>
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/mmu/tdp_mmu.c | 20 ++++++--------------
 arch/x86/kvm/mmu/tdp_mmu.h |  2 +-
 2 files changed, 7 insertions(+), 15 deletions(-)

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 91caa73a905b..9c66be7fb002 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1492,13 +1492,12 @@ static bool tdp_mmu_need_write_protect(struct kvm_mmu_page *sp)
 	return kvm_mmu_page_ad_need_write_protect(sp) || !kvm_ad_enabled();
 }
 
-static bool clear_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
-			   gfn_t start, gfn_t end)
+static void clear_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
+				  gfn_t start, gfn_t end)
 {
 	const u64 dbit = tdp_mmu_need_write_protect(root) ? PT_WRITABLE_MASK :
 							    shadow_dirty_mask;
 	struct tdp_iter iter;
-	bool spte_set = false;
 
 	rcu_read_lock();
 
@@ -1519,31 +1518,24 @@ static bool clear_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root,
 
 		if (tdp_mmu_set_spte_atomic(kvm, &iter, iter.old_spte & ~dbit))
 			goto retry;
-
-		spte_set = true;
 	}
 
 	rcu_read_unlock();
-	return spte_set;
 }
 
 /*
  * 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.
+ * memslot.
  */
-bool kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm,
+void kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm,
 				  const struct kvm_memory_slot *slot)
 {
 	struct kvm_mmu_page *root;
-	bool spte_set = false;
 
 	lockdep_assert_held_read(&kvm->mmu_lock);
 	for_each_valid_tdp_mmu_root_yield_safe(kvm, root, slot->as_id)
-		spte_set |= clear_dirty_gfn_range(kvm, root, slot->base_gfn,
-				slot->base_gfn + slot->npages);
-
-	return spte_set;
+		clear_dirty_gfn_range(kvm, root, slot->base_gfn,
+				      slot->base_gfn + slot->npages);
 }
 
 static void clear_dirty_pt_masked(struct kvm *kvm, struct kvm_mmu_page *root,
diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h
index 1b74e058a81c..d842bfe103ab 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.h
+++ b/arch/x86/kvm/mmu/tdp_mmu.h
@@ -34,7 +34,7 @@ bool kvm_tdp_mmu_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
 
 bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm,
 			     const struct kvm_memory_slot *slot, int min_level);
-bool kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm,
+void kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm,
 				  const struct kvm_memory_slot *slot);
 void kvm_tdp_mmu_clear_dirty_pt_masked(struct kvm *kvm,
 				       struct kvm_memory_slot *slot,
-- 
2.47.0.rc1.288.g06298d1525-goog