diff mbox series

[v9,17/32] virtio_ring: packed: introduce virtqueue_resize_packed()

Message ID 20220406034346.74409-18-xuanzhuo@linux.alibaba.com (mailing list archive)
State New, archived
Headers show
Series virtio pci support VIRTIO_F_RING_RESET (refactor vring) | expand

Commit Message

Xuan Zhuo April 6, 2022, 3:43 a.m. UTC
virtio ring packed supports resize.

Only after the new vring is successfully allocated based on the new num,
we will release the old vring. In any case, an error is returned,
indicating that the vring still points to the old vring.

In the case of an error, the caller must re-initialize(by
virtqueue_reinit_packed()) the virtqueue to ensure that the vring can be
used.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c | 40 ++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
diff mbox series

Patch

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 9a4f2db718bd..06f66b15c86c 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2059,6 +2059,46 @@  static struct virtqueue *vring_create_virtqueue_packed(
 	return NULL;
 }
 
+static int virtqueue_resize_packed(struct virtqueue *_vq, u32 num)
+{
+	dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr;
+	struct vring_packed_desc_event *driver, *device;
+	size_t ring_size_in_bytes, event_size_in_bytes;
+	struct vring_virtqueue *vq = to_vvq(_vq);
+	struct virtio_device *vdev = _vq->vdev;
+	struct vring_desc_state_packed *state;
+	struct vring_desc_extra *extra;
+	struct vring_packed_desc *ring;
+	int err;
+
+	if (vring_alloc_queue_packed(vdev, num, &ring, &driver, &device,
+				     &ring_dma_addr, &driver_event_dma_addr,
+				     &device_event_dma_addr,
+				     &ring_size_in_bytes, &event_size_in_bytes))
+		goto err_ring;
+
+
+	err = vring_alloc_state_extra_packed(num, &state, &extra);
+	if (err)
+		goto err_state_extra;
+
+	vring_free(&vq->vq);
+
+	vring_virtqueue_attach_packed(vq, num, ring, driver, device,
+				      ring_dma_addr, driver_event_dma_addr,
+				      device_event_dma_addr, ring_size_in_bytes,
+				      event_size_in_bytes, state, extra);
+	vring_virtqueue_init_packed(vq, vdev);
+	return 0;
+
+err_state_extra:
+	vring_free_queue(vdev, event_size_in_bytes, device, device_event_dma_addr);
+	vring_free_queue(vdev, event_size_in_bytes, driver, driver_event_dma_addr);
+	vring_free_queue(vdev, ring_size_in_bytes, ring, ring_dma_addr);
+err_ring:
+	return -ENOMEM;
+}
+
 
 /*
  * Generic functions and exported symbols.