* [PATCH 4/4] vhost: supported the virtio indirect desc of used ring
@ 2025-12-04 7:44 Wafer Xie
2025-12-04 8:42 ` Eugenio Perez Martin
0 siblings, 1 reply; 2+ messages in thread
From: Wafer Xie @ 2025-12-04 7:44 UTC (permalink / raw)
To: mst, eperezma, jasowang, qemu-devel; +Cc: leiyang, sgarzare, angus.chen, wafer
Retrieve the used ring buffers in the indirect descriptor area
of split shadow virtqueues.
Signed-off-by: Wafer Xie <wafer@jaguarmicro.com>
---
hw/virtio/vhost-shadow-virtqueue.c | 36 ++++++++++++++++++++++++++----
1 file changed, 32 insertions(+), 4 deletions(-)
diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c
index 94ad5c3a57..0ffb884196 100644
--- a/hw/virtio/vhost-shadow-virtqueue.c
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -636,12 +636,40 @@ static VirtQueueElement *vhost_svq_get_buf(VhostShadowVirtqueue *svq,
return NULL;
}
+ bool used_indirect = (svq->desc_state[used_elem.id].indirect_desc != NULL);
+
+ /* Free indirect descriptor table if it was used */
+ if (used_indirect) {
+ if (svq->indirect_ops && svq->indirect_ops->free) {
+ svq->indirect_ops->free(svq,
+ svq->desc_state[used_elem.id].indirect_desc,
+ svq->desc_state[used_elem.id].indirect_iova,
+ svq->desc_state[used_elem.id].indirect_size,
+ svq->indirect_ops->opaque);
+ }
+ svq->desc_state[used_elem.id].indirect_desc = NULL;
+ svq->desc_state[used_elem.id].indirect_iova = 0;
+ svq->desc_state[used_elem.id].indirect_size = 0;
+ }
+
num = svq->desc_state[used_elem.id].ndescs;
svq->desc_state[used_elem.id].ndescs = 0;
- last_used_chain = vhost_svq_last_desc_of_chain(svq, num, used_elem.id);
- svq->desc_next[last_used_chain] = svq->free_head;
- svq->free_head = used_elem.id;
- svq->num_free += num;
+
+ /*
+ * If using indirect descriptors, only 1 main descriptor is used.
+ * To maintain consistency with `add split`,
+ * we used 'num' as free descriptors.
+ */
+ if (used_indirect) {
+ svq->desc_next[used_elem.id] = svq->free_head;
+ svq->free_head = used_elem.id;
+ svq->num_free += num;
+ } else {
+ last_used_chain = vhost_svq_last_desc_of_chain(svq, num, used_elem.id);
+ svq->desc_next[last_used_chain] = svq->free_head;
+ svq->free_head = used_elem.id;
+ svq->num_free += num;
+ }
*len = used_elem.len;
return g_steal_pointer(&svq->desc_state[used_elem.id].elem);
--
2.34.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH 4/4] vhost: supported the virtio indirect desc of used ring
2025-12-04 7:44 [PATCH 4/4] vhost: supported the virtio indirect desc of used ring Wafer Xie
@ 2025-12-04 8:42 ` Eugenio Perez Martin
0 siblings, 0 replies; 2+ messages in thread
From: Eugenio Perez Martin @ 2025-12-04 8:42 UTC (permalink / raw)
To: Wafer Xie; +Cc: mst, jasowang, qemu-devel, leiyang, sgarzare, angus.chen
On Thu, Dec 4, 2025 at 8:45 AM Wafer Xie <wafer@jaguarmicro.com> wrote:
>
> Retrieve the used ring buffers in the indirect descriptor area
> of split shadow virtqueues.
>
This needs to be squashed with the previous patch. Otherwise, we are
allocating & mapping on each indirect descriptor but not freeing &
unmapping.
> Signed-off-by: Wafer Xie <wafer@jaguarmicro.com>
> ---
> hw/virtio/vhost-shadow-virtqueue.c | 36 ++++++++++++++++++++++++++----
> 1 file changed, 32 insertions(+), 4 deletions(-)
>
> diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c
> index 94ad5c3a57..0ffb884196 100644
> --- a/hw/virtio/vhost-shadow-virtqueue.c
> +++ b/hw/virtio/vhost-shadow-virtqueue.c
> @@ -636,12 +636,40 @@ static VirtQueueElement *vhost_svq_get_buf(VhostShadowVirtqueue *svq,
> return NULL;
> }
>
> + bool used_indirect = (svq->desc_state[used_elem.id].indirect_desc != NULL);
> +
> + /* Free indirect descriptor table if it was used */
> + if (used_indirect) {
> + if (svq->indirect_ops && svq->indirect_ops->free) {
> + svq->indirect_ops->free(svq,
> + svq->desc_state[used_elem.id].indirect_desc,
> + svq->desc_state[used_elem.id].indirect_iova,
> + svq->desc_state[used_elem.id].indirect_size,
> + svq->indirect_ops->opaque);
> + }
> + svq->desc_state[used_elem.id].indirect_desc = NULL;
> + svq->desc_state[used_elem.id].indirect_iova = 0;
> + svq->desc_state[used_elem.id].indirect_size = 0;
> + }
> +
> num = svq->desc_state[used_elem.id].ndescs;
> svq->desc_state[used_elem.id].ndescs = 0;
> - last_used_chain = vhost_svq_last_desc_of_chain(svq, num, used_elem.id);
> - svq->desc_next[last_used_chain] = svq->free_head;
> - svq->free_head = used_elem.id;
> - svq->num_free += num;
> +
> + /*
> + * If using indirect descriptors, only 1 main descriptor is used.
> + * To maintain consistency with `add split`,
> + * we used 'num' as free descriptors.
> + */
> + if (used_indirect) {
> + svq->desc_next[used_elem.id] = svq->free_head;
> + svq->free_head = used_elem.id;
> + svq->num_free += num;
> + } else {
> + last_used_chain = vhost_svq_last_desc_of_chain(svq, num, used_elem.id);
> + svq->desc_next[last_used_chain] = svq->free_head;
> + svq->free_head = used_elem.id;
> + svq->num_free += num;
> + }
>
> *len = used_elem.len;
> return g_steal_pointer(&svq->desc_state[used_elem.id].elem);
> --
> 2.34.1
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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