Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio/vhost fixes and cleanups from Michael Tsirkin:
 "Fixes and cleanups all over the place"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost/scsi: Use copy_to_iter() to send control queue response
  vhost: return EINVAL if iovecs size does not match the message size
  virtio-balloon: tweak config_changed implementation
  virtio: don't allocate vqs when names[i] = NULL
  virtio_pci: use queue idx instead of array idx to set up the vq
  virtio: document virtio_config_ops restrictions
  virtio: fix virtio_config_ops description

2 files changed, 18 insertions, 10 deletions

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 8e10ab436d1f..344684f3e2e4 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1127,16 +1127,18 @@ vhost_scsi_send_tmf_reject(struct vhost_scsi *vs,
 			   struct vhost_virtqueue *vq,
 			   struct vhost_scsi_ctx *vc)
 {
-	struct virtio_scsi_ctrl_tmf_resp __user *resp;
 	struct virtio_scsi_ctrl_tmf_resp rsp;
+	struct iov_iter iov_iter;
 	int ret;
 
 	pr_debug("%s\n", __func__);
 	memset(&rsp, 0, sizeof(rsp));
 	rsp.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
-	resp = vq->iov[vc->out].iov_base;
-	ret = __copy_to_user(resp, &rsp, sizeof(rsp));
-	if (!ret)
+
+	iov_iter_init(&iov_iter, READ, &vq->iov[vc->out], vc->in, sizeof(rsp));
+
+	ret = copy_to_iter(&rsp, sizeof(rsp), &iov_iter);
+	if (likely(ret == sizeof(rsp)))
 		vhost_add_used_and_signal(&vs->dev, vq, vc->head, 0);
 	else
 		pr_err("Faulted on virtio_scsi_ctrl_tmf_resp\n");
@@ -1147,16 +1149,18 @@ vhost_scsi_send_an_resp(struct vhost_scsi *vs,
 			struct vhost_virtqueue *vq,
 			struct vhost_scsi_ctx *vc)
 {
-	struct virtio_scsi_ctrl_an_resp __user *resp;
 	struct virtio_scsi_ctrl_an_resp rsp;
+	struct iov_iter iov_iter;
 	int ret;
 
 	pr_debug("%s\n", __func__);
 	memset(&rsp, 0, sizeof(rsp));	/* event_actual = 0 */
 	rsp.response = VIRTIO_SCSI_S_OK;
-	resp = vq->iov[vc->out].iov_base;
-	ret = __copy_to_user(resp, &rsp, sizeof(rsp));
-	if (!ret)
+
+	iov_iter_init(&iov_iter, READ, &vq->iov[vc->out], vc->in, sizeof(rsp));
+
+	ret = copy_to_iter(&rsp, sizeof(rsp), &iov_iter);
+	if (likely(ret == sizeof(rsp)))
 		vhost_add_used_and_signal(&vs->dev, vq, vc->head, 0);
 	else
 		pr_err("Faulted on virtio_scsi_ctrl_an_resp\n");
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 9f7942cbcbb2..bac939af8dbb 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1034,8 +1034,10 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
 	int type, ret;
 
 	ret = copy_from_iter(&type, sizeof(type), from);
-	if (ret != sizeof(type))
+	if (ret != sizeof(type)) {
+		ret = -EINVAL;
 		goto done;
+	}
 
 	switch (type) {
 	case VHOST_IOTLB_MSG:
@@ -1054,8 +1056,10 @@ ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
 
 	iov_iter_advance(from, offset);
 	ret = copy_from_iter(&msg, sizeof(msg), from);
-	if (ret != sizeof(msg))
+	if (ret != sizeof(msg)) {
+		ret = -EINVAL;
 		goto done;
+	}
 	if (vhost_process_iotlb_msg(dev, &msg)) {
 		ret = -EFAULT;
 		goto done;