On 2026/07/24 7:30, Connor Kite wrote:
Adds a handler 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 | 4 ++++
hw/virtio/vhost-shadow-virtqueue.h | 14 ++++++++++++++
2 files changed, 18 insertions(+)
diff --git a/hw/virtio/vhost-shadow-virtqueue.c
b/hw/virtio/vhost-shadow-virtqueue.c
index bcb7f2ffc7..eb86c1ee37 100644
--- a/hw/virtio/vhost-shadow-virtqueue.c
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -669,6 +669,10 @@ static void vhost_svq_flush(VhostShadowVirtqueue *svq,
break;
}
+ if (svq->ops && svq->ops->used_handler) {
+ svq->ops->used_handler(svq, elem, svq->ops_opaque);
The error of the handler that may have left elem stale is ignored here.
Regards,
Akihiko Odaki
+ }
+
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..ccfeee36d7 100644
--- a/hw/virtio/vhost-shadow-virtqueue.h
+++ b/hw/virtio/vhost-shadow-virtqueue.h
@@ -56,8 +56,22 @@ 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
+ */
+typedef int (*VirtQueueUsedCallback)(VhostShadowVirtqueue *svq,
+ VirtQueueElement *elem,
+ void *vq_callback_opaque);
+
typedef struct VhostShadowVirtqueueOps {
VirtQueueAvailCallback avail_handler;
+ VirtQueueUsedCallback used_handler;
} VhostShadowVirtqueueOps;
/* Shadow virtqueue to relay notifications */
