On Mon, Sep 22, 2025 at 1:42 AM Michael S. Tsirkin [off-list ref] wrote:

On Fri, Sep 19, 2025 at 03:31:50PM +0800, Jason Wang wrote:

quoted

Factor out core logic of buffer detaching and leave the id population
to the caller so in order can just call the core logic.

Acked-by: Eugenio Pérez <eperezma@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/virtio/virtio_ring.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 0949675a3d12..a83d08070e8a 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c

@@ -1662,8 +1662,8 @@ static bool virtqueue_kick_prepare_packed(struct vring_virtqueue *vq)
      return needs_kick;
 }

-static void detach_buf_packed(struct vring_virtqueue *vq,
-                           unsigned int id, void **ctx)
+static void detach_buf_packed_in_order(struct vring_virtqueue *vq,
+                                    unsigned int id, void **ctx)
 {
      struct vring_desc_state_packed *state = NULL;
      struct vring_packed_desc *desc;

@@ -1674,8 +1674,6 @@ static void detach_buf_packed(struct vring_virtqueue *vq,
      /* Clear data ptr. */
      state->data = NULL;

-     vq->packed.desc_extra[state->last].next = vq->free_head;
-     vq->free_head = id;
      vq->vq.num_free += state->num;

      if (unlikely(vq->use_map_api)) {

@@ -1712,6 +1710,17 @@ static void detach_buf_packed(struct vring_virtqueue *vq,
      }
 }

+static void detach_buf_packed(struct vring_virtqueue *vq,
+                           unsigned int id, void **ctx)
+{
+     struct vring_desc_state_packed *state = &vq->packed.desc_state[id];
+
+     vq->packed.desc_extra[state->last].next = vq->free_head;
+     vq->free_head = id;
+
+     return detach_buf_packed_in_order(vq, id, ctx);
+}
+

Wait what? return in a void function?
How does this compile?

It looks like it passes the compiling since detach_buf_packed_in_order
returns void as well :(

I'm guessing it's tweaked by a follow
up patch?

Nope. Let me drop the return here.

Thanks

quoted

 static inline bool is_used_desc_packed(const struct vring_virtqueue *vq,
                                     u16 idx, bool used_wrap_counter)
 {
--
2.31.1