Adds a callback to shadow virtqueues in order to enable non-default processing of used vring elements from the device.
Signed-off-by: Connor Kite <[email protected]> --- hw/virtio/vhost-shadow-virtqueue.c | 9 +++++++++ hw/virtio/vhost-shadow-virtqueue.h | 16 ++++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index c8831d52be..496e7e58a3 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -675,6 +675,15 @@ static void vhost_svq_flush(VhostShadowVirtqueue *svq, break; } + if (svq->ops && svq->ops->used_callback) { + int r = svq->ops->used_callback(svq, elem, svq->ops_opaque); + + if (r < 0) { + /* VQ or handler is broken. Do not set guest notifier */ + return; + } + } + if (unlikely(i >= svq->vring.num)) { qemu_log_mask(LOG_GUEST_ERROR, "More than %u used buffers obtained in a %u size SVQ", diff --git a/hw/virtio/vhost-shadow-virtqueue.h b/hw/virtio/vhost-shadow-virtqueue.h index ec16a1e838..fd68319fb7 100644 --- a/hw/virtio/vhost-shadow-virtqueue.h +++ b/hw/virtio/vhost-shadow-virtqueue.h @@ -56,8 +56,24 @@ typedef int (*VirtQueueAvailCallback)(VhostShadowVirtqueue *svq, VirtQueueElement *elem, void *vq_callback_opaque); +/** + * Callback to handle a used buffer + * + * @svq: Shadow virtqueue + * @elem: Element placed in the queue by the device + * @vq_callback_opaque: Used to pass arguments to callback + * + * Returns 0 if the vq is running as expected. Returns a negative errno on + * failure. The callback should not add used elements to the vq shadowed + * by the svq as that is done separately after the callback returns. + */ +typedef int (*VirtQueueUsedCallback)(VhostShadowVirtqueue *svq, + VirtQueueElement *elem, + void *vq_callback_opaque); + typedef struct VhostShadowVirtqueueOps { VirtQueueAvailCallback avail_handler; + VirtQueueUsedCallback used_callback; } VhostShadowVirtqueueOps; /* Shadow virtqueue to relay notifications */ -- 2.43.0
