1 files changed, 16 insertions, 0 deletions

diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index 707a1f06dc5d..f675162663f0 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -309,6 +309,22 @@ static inline unsigned int kvm_get_vmid_bits(void)
         return 8;
 }
 
+/*
+ * We are not in the kvm->srcu critical section most of the time, so we take
+ * the SRCU read lock here. Since we copy the data from the user page, we
+ * can immediately drop the lock again.
+ */
+static inline int kvm_read_guest_lock(struct kvm *kvm,
+                                      gpa_t gpa, void *data, unsigned long len)
+{
+        int srcu_idx = srcu_read_lock(&kvm->srcu);
+        int ret = kvm_read_guest(kvm, gpa, data, len);
+
+        srcu_read_unlock(&kvm->srcu, srcu_idx);
+
+        return ret;
+}
+
 static inline void *kvm_get_hyp_vector(void)
 {
         return kvm_ksym_ref(__kvm_hyp_vector);