linux-kernel - [PATCH v12 51/84] KVM: PPC: e500: Mark "struct page" dirty in kvmppc_e500_shadow

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Message-ID: <20240726235234.228822-52-seanjc@google.com>
Date: Fri, 26 Jul 2024 16:52:00 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Paolo Bonzini <pbonzini@...hat.com>, Marc Zyngier <maz@...nel.org>, 
	Oliver Upton <oliver.upton@...ux.dev>, Tianrui Zhao <zhaotianrui@...ngson.cn>, 
	Bibo Mao <maobibo@...ngson.cn>, Huacai Chen <chenhuacai@...nel.org>, 
	Michael Ellerman <mpe@...erman.id.au>, Anup Patel <anup@...infault.org>, 
	Paul Walmsley <paul.walmsley@...ive.com>, Palmer Dabbelt <palmer@...belt.com>, 
	Albert Ou <aou@...s.berkeley.edu>, Christian Borntraeger <borntraeger@...ux.ibm.com>, 
	Janosch Frank <frankja@...ux.ibm.com>, Claudio Imbrenda <imbrenda@...ux.ibm.com>, 
	Sean Christopherson <seanjc@...gle.com>
Cc: kvm@...r.kernel.org, linux-arm-kernel@...ts.infradead.org, 
	kvmarm@...ts.linux.dev, loongarch@...ts.linux.dev, linux-mips@...r.kernel.org, 
	linuxppc-dev@...ts.ozlabs.org, kvm-riscv@...ts.infradead.org, 
	linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org, 
	David Matlack <dmatlack@...gle.com>, David Stevens <stevensd@...omium.org>
Subject: [PATCH v12 51/84] KVM: PPC: e500: Mark "struct page" dirty in kvmppc_e500_shadow_map()

Mark the underlying page as dirty in kvmppc_e500_ref_setup()'s sole
caller, kvmppc_e500_shadow_map(), which will allow converting e500 to
__kvm_faultin_pfn() + kvm_release_faultin_page() without having to do
a weird dance between ref_setup() and shadow_map().

Opportunistically drop the redundant kvm_set_pfn_accessed(), as
shadow_map() puts the page via kvm_release_pfn_clean().

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/powerpc/kvm/e500_mmu_host.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index c664fdec75b1..5c2adfd19e12 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -242,7 +242,7 @@ static inline int tlbe_is_writable(struct kvm_book3e_206_tlb_entry *tlbe)
 	return tlbe->mas7_3 & (MAS3_SW|MAS3_UW);
 }
 
-static inline void kvmppc_e500_ref_setup(struct tlbe_ref *ref,
+static inline bool kvmppc_e500_ref_setup(struct tlbe_ref *ref,
 					 struct kvm_book3e_206_tlb_entry *gtlbe,
 					 kvm_pfn_t pfn, unsigned int wimg)
 {
@@ -252,11 +252,7 @@ static inline void kvmppc_e500_ref_setup(struct tlbe_ref *ref,
 	/* Use guest supplied MAS2_G and MAS2_E */
 	ref->flags |= (gtlbe->mas2 & MAS2_ATTRIB_MASK) | wimg;
 
-	/* Mark the page accessed */
-	kvm_set_pfn_accessed(pfn);
-
-	if (tlbe_is_writable(gtlbe))
-		kvm_set_pfn_dirty(pfn);
+	return tlbe_is_writable(gtlbe);
 }
 
 static inline void kvmppc_e500_ref_release(struct tlbe_ref *ref)
@@ -337,6 +333,7 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
 	unsigned int wimg = 0;
 	pgd_t *pgdir;
 	unsigned long flags;
+	bool writable = false;
 
 	/* used to check for invalidations in progress */
 	mmu_seq = kvm->mmu_invalidate_seq;
@@ -490,7 +487,9 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
 			goto out;
 		}
 	}
-	kvmppc_e500_ref_setup(ref, gtlbe, pfn, wimg);
+	writable = kvmppc_e500_ref_setup(ref, gtlbe, pfn, wimg);
+	if (writable)
+		kvm_set_pfn_dirty(pfn);
 
 	kvmppc_e500_setup_stlbe(&vcpu_e500->vcpu, gtlbe, tsize,
 				ref, gvaddr, stlbe);
-- 
2.46.0.rc1.232.g9752f9e123-goog