virtio_input: Improve freeze handling

When executing suspend to ram, if lacking the operations
to reset device and free unused buffers before deleting
a vq, resource leaks and inconsistent device status will
appear.

According to chapter "3.3.1 Driver Requirements: Device Cleanup:"
of virtio-specification:
  Driver MUST ensure a virtqueue isn’t live
  (by device reset) before removing exposed
  buffers.

Therefore, modify the virtinput_freeze function to reset the
device and delete the unused buffers before deleting the
virtqueue, just like virtinput_remove does.

Co-developed-by: Ying Xu <ying123.xu@samsung.com>
Signed-off-by: Ying Xu <ying123.xu@samsung.com>
Co-developed-by: Junnan Wu <junnan01.wu@samsung.com>
Signed-off-by: Junnan Wu <junnan01.wu@samsung.com>
Signed-off-by: Ying Gao <ying01.gao@samsung.com>
Message-Id: <20250812095118.3622717-1-ying01.gao@samsung.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/virtio/virtio_input.c b/drivers/virtio/virtio_input.c
index a5d63269f20b945640a9dbff3d991413549589fb..d0728285b6ce969b356563ed840e99cd0e4b1b0c 100644 (file)
--- a/drivers/virtio/virtio_input.c
+++ b/drivers/virtio/virtio_input.c
@@ -360,11 +360,15 @@ static int virtinput_freeze(struct virtio_device *vdev)
 {
        struct virtio_input *vi = vdev->priv;
        unsigned long flags;
+       void *buf;
 
        spin_lock_irqsave(&vi->lock, flags);
        vi->ready = false;
        spin_unlock_irqrestore(&vi->lock, flags);
 
+       virtio_reset_device(vdev);
+       while ((buf = virtqueue_detach_unused_buf(vi->sts)) != NULL)
+               kfree(buf);
        vdev->config->del_vqs(vdev);
        return 0;
 }