diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index aa3741b8778d..cfa88a60a38f 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -733,12 +733,11 @@ static int vdpasim_dma_unmap(struct vdpa_device *vdpa, unsigned int asid,
 	if (asid >= vdpasim->dev_attr.nas)
 		return -EINVAL;
 
+	spin_lock(&vdpasim->iommu_lock);
 	if (vdpasim->iommu_pt[asid]) {
 		vhost_iotlb_reset(&vdpasim->iommu[asid]);
 		vdpasim->iommu_pt[asid] = false;
 	}
-
-	spin_lock(&vdpasim->iommu_lock);
 	vhost_iotlb_del_range(&vdpasim->iommu[asid], iova, iova + size - 1);
 	spin_unlock(&vdpasim->iommu_lock);