linux-kernel - [PATCH 03/18] KVM: x86/mmu: Fold all of make_spte()'s writable handling into one if-else

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Message-ID: <20241011021051.1557902-4-seanjc@google.com>
Date: Thu, 10 Oct 2024 19:10:35 -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 03/18] KVM: x86/mmu: Fold all of make_spte()'s writable
 handling into one if-else

Now that make_spte() no longer uses a funky goto to bail out for a special
case of its unsync handling, combine all of the unsync vs. writable logic
into a single if-else statement.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/mmu/spte.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c
index 09ce93c4916a..030813781a63 100644
--- a/arch/x86/kvm/mmu/spte.c
+++ b/arch/x86/kvm/mmu/spte.c
@@ -217,8 +217,6 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 	spte |= (u64)pfn << PAGE_SHIFT;
 
 	if (pte_access & ACC_WRITE_MASK) {
-		spte |= PT_WRITABLE_MASK | shadow_mmu_writable_mask;
-
 		/*
 		 * Unsync shadow pages that are reachable by the new, writable
 		 * SPTE.  Write-protect the SPTE if the page can't be unsync'd,
@@ -233,16 +231,13 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
 		 * guaranteed by both the shadow MMU and the TDP MMU.
 		 */
 		if ((!is_last_spte(old_spte, level) || !is_writable_pte(old_spte)) &&
-		    mmu_try_to_unsync_pages(vcpu->kvm, slot, gfn, synchronizing, prefetch)) {
+		    mmu_try_to_unsync_pages(vcpu->kvm, slot, gfn, synchronizing, prefetch))
 			wrprot = true;
-			pte_access &= ~ACC_WRITE_MASK;
-			spte &= ~(PT_WRITABLE_MASK | shadow_mmu_writable_mask);
-		}
+		else
+			spte |= PT_WRITABLE_MASK | shadow_mmu_writable_mask |
+				spte_shadow_dirty_mask(spte);
 	}
 
-	if (pte_access & ACC_WRITE_MASK)
-		spte |= spte_shadow_dirty_mask(spte);
-
 	if (prefetch && !synchronizing)
 		spte = mark_spte_for_access_track(spte);
 
-- 
2.47.0.rc1.288.g06298d1525-goog