vhost: Expose vhost_svq_available_slots()

Next patches in this series will delay the polling
and checking of buffers until either the SVQ is
full or control commands shadow buffers are full,
no longer perform an immediate poll and check of
the device's used buffers for each CVQ state load command.

To achieve this, this patch exposes
vhost_svq_available_slots(), allowing QEMU to know
whether the SVQ is full.

Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
Acked-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <25938079f0bd8185fd664c64e205e629f7a966be.1697165821.git.yin31149@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c
index e731b1d..fc5f408 100644 (file)
--- a/hw/virtio/vhost-shadow-virtqueue.c
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -66,7 +66,7 @@ bool vhost_svq_valid_features(uint64_t features, Error **errp)
  *
  * @svq: The svq
  */
-static uint16_t vhost_svq_available_slots(const VhostShadowVirtqueue *svq)
+uint16_t vhost_svq_available_slots(const VhostShadowVirtqueue *svq)
 {
     return svq->num_free;
 }

diff --git a/hw/virtio/vhost-shadow-virtqueue.h b/hw/virtio/vhost-shadow-virtqueue.h
index 5bce678..19c842a 100644 (file)
--- a/hw/virtio/vhost-shadow-virtqueue.h
+++ b/hw/virtio/vhost-shadow-virtqueue.h
@@ -114,6 +114,7 @@ typedef struct VhostShadowVirtqueue {
 
 bool vhost_svq_valid_features(uint64_t features, Error **errp);
 
+uint16_t vhost_svq_available_slots(const VhostShadowVirtqueue *svq);
 void vhost_svq_push_elem(VhostShadowVirtqueue *svq,
                          const VirtQueueElement *elem, uint32_t len);
 int vhost_svq_add(VhostShadowVirtqueue *svq, const struct iovec *out_sg,