[RFC PATCH v5 08/38] KVM: arm64: Unlock memslots after stage 2 tables are freed

[Alexandru Elisei]

Unpin the backing pages mapped at stage 2 after the stage 2 translation
tables are destroyed.

Signed-off-by: Alexandru Elisei <alexandru.elisei at arm.com>
---
 arch/arm64/kvm/mmu.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index cd6f1bc7842d..072e2aba371f 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1627,11 +1627,19 @@ int kvm_mmu_lock_memslot(struct kvm *kvm, u64 slot, u64 flags)
 	return ret;
 }
 
-static void unlock_memslot(struct kvm *kvm, struct kvm_memory_slot *memslot)
+static void __unlock_memslot(struct kvm *kvm, struct kvm_memory_slot *memslot)
 {
 	bool writable = memslot->arch.flags & KVM_MEMSLOT_LOCK_WRITE;
 	unsigned long npages = memslot->npages;
 
+	unpin_memslot_pages(memslot, writable);
+	account_locked_vm(current->mm, npages, false);
+
+	memslot->arch.flags &= ~KVM_MEMSLOT_LOCK_MASK;
+}
+
+static void unlock_memslot(struct kvm *kvm, struct kvm_memory_slot *memslot)
+{
 	/*
 	 * MMU maintenace operations aren't performed on an unlocked memslot.
 	 * Unmap it from stage 2 so the abort handler performs the necessary
@@ -1640,10 +1648,7 @@ static void unlock_memslot(struct kvm *kvm, struct kvm_memory_slot *memslot)
 	if (kvm_mmu_has_pending_ops(kvm))
 		kvm_arch_flush_shadow_memslot(kvm, memslot);
 
-	unpin_memslot_pages(memslot, writable);
-	account_locked_vm(current->mm, npages, false);
-
-	memslot->arch.flags &= ~KVM_MEMSLOT_LOCK_MASK;
+	__unlock_memslot(kvm, memslot);
 }
 
 int kvm_mmu_unlock_memslot(struct kvm *kvm, u64 slot, u64 flags)
@@ -1951,7 +1956,15 @@ void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen)
 
 void kvm_arch_flush_shadow_all(struct kvm *kvm)
 {
+	struct kvm_memory_slot *memslot;
+
 	kvm_free_stage2_pgd(&kvm->arch.mmu);
+
+	kvm_for_each_memslot(memslot, kvm_memslots(kvm)) {
+		if (!memslot_is_locked(memslot))
+			continue;
+		__unlock_memslot(kvm, memslot);
+	}
 }
 
 void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
-- 
2.33.1