linux-kernel - [PATCH v7 6/8] KVM: arm64: Migrate to __kvm_follow

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Message-ID: <20230704075054.3344915-7-stevensd@google.com>
Date:   Tue,  4 Jul 2023 16:50:51 +0900
From:   David Stevens <stevensd@...omium.org>
To:     Sean Christopherson <seanjc@...gle.com>
Cc:     Marc Zyngier <maz@...nel.org>,
        Michael Ellerman <mpe@...erman.id.au>,
        Peter Xu <peterx@...hat.com>,
        linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.linux.dev,
        linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org,
        kvm@...r.kernel.org, David Stevens <stevensd@...omium.org>
Subject: [PATCH v7 6/8] KVM: arm64: Migrate to __kvm_follow_pfn

From: David Stevens <stevensd@...omium.org>

Migrate from __gfn_to_pfn_memslot to __kvm_follow_pfn.

Signed-off-by: David Stevens <stevensd@...omium.org>
---
 arch/arm64/kvm/mmu.c | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 6db9ef288ec3..c706530d304d 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1334,7 +1334,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 			  unsigned long fault_status)
 {
 	int ret = 0;
-	bool write_fault, writable, force_pte = false;
+	bool write_fault = kvm_is_write_fault(vcpu);
+	bool force_pte = false;
 	bool exec_fault, mte_allowed;
 	bool device = false;
 	unsigned long mmu_seq;
@@ -1342,16 +1343,19 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 	struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
 	struct vm_area_struct *vma;
 	short vma_shift;
-	gfn_t gfn;
 	kvm_pfn_t pfn;
 	bool logging_active = memslot_is_logging(memslot);
 	unsigned long fault_level = kvm_vcpu_trap_get_fault_level(vcpu);
 	long vma_pagesize, fault_granule;
 	enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R;
 	struct kvm_pgtable *pgt;
+	struct kvm_follow_pfn foll = {
+		.slot = memslot,
+		.flags = FOLL_GET | (write_fault ? FOLL_WRITE : 0),
+		.allow_write_mapping = true,
+	};
 
 	fault_granule = 1UL << ARM64_HW_PGTABLE_LEVEL_SHIFT(fault_level);
-	write_fault = kvm_is_write_fault(vcpu);
 	exec_fault = kvm_vcpu_trap_is_exec_fault(vcpu);
 	VM_BUG_ON(write_fault && exec_fault);
 
@@ -1425,7 +1429,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 	if (vma_pagesize == PMD_SIZE || vma_pagesize == PUD_SIZE)
 		fault_ipa &= ~(vma_pagesize - 1);
 
-	gfn = fault_ipa >> PAGE_SHIFT;
+	foll.gfn = fault_ipa >> PAGE_SHIFT;
 	mte_allowed = kvm_vma_mte_allowed(vma);
 
 	/* Don't use the VMA after the unlock -- it may have vanished */
@@ -1433,7 +1437,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 
 	/*
 	 * Read mmu_invalidate_seq so that KVM can detect if the results of
-	 * vma_lookup() or __gfn_to_pfn_memslot() become stale prior to
+	 * vma_lookup() or __kvm_follow_pfn() become stale prior to
 	 * acquiring kvm->mmu_lock.
 	 *
 	 * Rely on mmap_read_unlock() for an implicit smp_rmb(), which pairs
@@ -1442,8 +1446,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 	mmu_seq = vcpu->kvm->mmu_invalidate_seq;
 	mmap_read_unlock(current->mm);
 
-	pfn = __gfn_to_pfn_memslot(memslot, gfn, false, false, NULL,
-				   write_fault, &writable, NULL);
+	pfn = __kvm_follow_pfn(&foll);
 	if (pfn == KVM_PFN_ERR_HWPOISON) {
 		kvm_send_hwpoison_signal(hva, vma_shift);
 		return 0;
@@ -1468,7 +1471,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 		 * Only actually map the page as writable if this was a write
 		 * fault.
 		 */
-		writable = false;
+		foll.writable = false;
 	}
 
 	if (exec_fault && device)
@@ -1508,7 +1511,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 		}
 	}
 
-	if (writable)
+	if (foll.writable)
 		prot |= KVM_PGTABLE_PROT_W;
 
 	if (exec_fault)
@@ -1534,9 +1537,9 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 					     KVM_PGTABLE_WALK_SHARED);
 
 	/* Mark the page dirty only if the fault is handled successfully */
-	if (writable && !ret) {
+	if (foll.writable && !ret) {
 		kvm_set_pfn_dirty(pfn);
-		mark_page_dirty_in_slot(kvm, memslot, gfn);
+		mark_page_dirty_in_slot(kvm, memslot, foll.gfn);
 	}
 
 out_unlock:
-- 
2.41.0.255.g8b1d071c50-goog