linux-kernel - [PATCH 05/18] KVM: arm64: Pass walk flags to kvm_pgtable_stage2

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Message-ID: <20241104133204.85208-6-qperret@google.com>
Date: Mon,  4 Nov 2024 13:31:51 +0000
From: Quentin Perret <qperret@...gle.com>
To: Marc Zyngier <maz@...nel.org>, Oliver Upton <oliver.upton@...ux.dev>, 
	Joey Gouly <joey.gouly@....com>, Suzuki K Poulose <suzuki.poulose@....com>, 
	Zenghui Yu <yuzenghui@...wei.com>, Catalin Marinas <catalin.marinas@....com>, 
	Will Deacon <will@...nel.org>
Cc: Fuad Tabba <tabba@...gle.com>, Vincent Donnefort <vdonnefort@...gle.com>, 
	Sebastian Ene <sebastianene@...gle.com>, linux-arm-kernel@...ts.infradead.org, 
	kvmarm@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: [PATCH 05/18] KVM: arm64: Pass walk flags to kvm_pgtable_stage2_mkyoung

kvm_pgtable_stage2_mkyoung currently assumes that it is being called
from a 'shared' walker, which will not be true once called from pKVM.
To allow for the re-use of that function, make the walk flags one of
its parameters.

Signed-off-by: Quentin Perret <qperret@...gle.com>
---
 arch/arm64/include/asm/kvm_pgtable.h | 4 +++-
 arch/arm64/kvm/hyp/pgtable.c         | 7 +++----
 arch/arm64/kvm/mmu.c                 | 3 ++-
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
index 03f4c3d7839c..442a45d38e23 100644
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h
@@ -669,6 +669,7 @@ int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size);
  * kvm_pgtable_stage2_mkyoung() - Set the access flag in a page-table entry.
  * @pgt:	Page-table structure initialised by kvm_pgtable_stage2_init*().
  * @addr:	Intermediate physical address to identify the page-table entry.
+ * @flags:	Flags to control the page-table walk (ex. a shared walk)
  *
  * The offset of @addr within a page is ignored.
  *
@@ -677,7 +678,8 @@ int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size);
  *
  * Return: The old page-table entry prior to setting the flag, 0 on failure.
  */
-kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr);
+kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr,
+				     enum kvm_pgtable_walk_flags flags);
 
 /**
  * kvm_pgtable_stage2_test_clear_young() - Test and optionally clear the access
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index b11bcebac908..fa25062f0590 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -1245,15 +1245,14 @@ int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size)
 					NULL, NULL, 0);
 }
 
-kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr)
+kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr,
+				     enum kvm_pgtable_walk_flags flags)
 {
 	kvm_pte_t pte = 0;
 	int ret;
 
 	ret = stage2_update_leaf_attrs(pgt, addr, 1, KVM_PTE_LEAF_ATTR_LO_S2_AF, 0,
-				       &pte, NULL,
-				       KVM_PGTABLE_WALK_HANDLE_FAULT |
-				       KVM_PGTABLE_WALK_SHARED);
+				       &pte, NULL, flags);
 	if (!ret)
 		dsb(ishst);
 
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 0f7658aefa1a..27e1b281f402 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1708,6 +1708,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 /* Resolve the access fault by making the page young again. */
 static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
 {
+	enum kvm_pgtable_walk_flags flags = KVM_PGTABLE_WALK_HANDLE_FAULT | KVM_PGTABLE_WALK_SHARED;
 	kvm_pte_t pte;
 	struct kvm_s2_mmu *mmu;
 
@@ -1715,7 +1716,7 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
 
 	read_lock(&vcpu->kvm->mmu_lock);
 	mmu = vcpu->arch.hw_mmu;
-	pte = kvm_pgtable_stage2_mkyoung(mmu->pgt, fault_ipa);
+	pte = kvm_pgtable_stage2_mkyoung(mmu->pgt, fault_ipa, flags);
 	read_unlock(&vcpu->kvm->mmu_lock);
 
 	if (kvm_pte_valid(pte))
-- 
2.47.0.163.g1226f6d8fa-goog