[PATCH v5 05/10] vdpa: Extract vhost_vdpa_net_cvq_add from vhost_vdpa_net_handle_ctrl_avail

[Eugenio Pérez]

So we can reuse it to inject state messages.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
--
v5:
* Do not use an artificial !NULL VirtQueueElement
* Use only out size instead of iovec dev_buffers for these functions.
---
 net/vhost-vdpa.c | 73 ++++++++++++++++++++++++++++++++----------------
 1 file changed, 49 insertions(+), 24 deletions(-)

diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index c6699edfbc..33bf3d6409 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -329,6 +329,52 @@ static bool vhost_vdpa_net_cvq_map_elem(VhostVDPAState *s,
     return true;
 }
 
+static virtio_net_ctrl_ack vhost_vdpa_net_cvq_add(VhostVDPAState *s,
+                                                  size_t out_len)
+{
+    /* Buffers for the device */
+    const struct iovec out = {
+        .iov_base = s->cvq_cmd_out_buffer,
+        .iov_len = out_len,
+    };
+    const struct iovec in = {
+        .iov_base = s->cvq_cmd_in_buffer,
+        .iov_len = sizeof(virtio_net_ctrl_ack),
+    };
+    VhostShadowVirtqueue *svq = g_ptr_array_index(s->vhost_vdpa.shadow_vqs, 0);
+    /* in buffer used for device model */
+    virtio_net_ctrl_ack status;
+    size_t dev_written;
+    int r;
+
+    r = vhost_svq_add(svq, &out, 1, &in, 1, NULL);
+    if (unlikely(r != 0)) {
+        if (unlikely(r == -ENOSPC)) {
+            qemu_log_mask(LOG_GUEST_ERROR, "%s: No space on device queue\n",
+                          __func__);
+        }
+        return VIRTIO_NET_ERR;
+    }
+
+    /*
+     * We can poll here since we've had BQL from the time we sent the
+     * descriptor. Also, we need to take the answer before SVQ pulls by itself,
+     * when BQL is released
+     */
+    dev_written = vhost_svq_poll(svq);
+    if (unlikely(dev_written < sizeof(status))) {
+        error_report("Insufficient written data (%zu)", dev_written);
+        return VIRTIO_NET_ERR;
+    }
+
+    memcpy(&status, s->cvq_cmd_in_buffer, sizeof(status));
+    if (status != VIRTIO_NET_OK) {
+        return VIRTIO_NET_ERR;
+    }
+
+    return VIRTIO_NET_OK;
+}
+
 /**
  * Do not forward commands not supported by SVQ. Otherwise, the device could
  * accept it and qemu would not know how to update the device model.
@@ -375,7 +421,7 @@ static int 
vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,
                                             void *opaque)
 {
     VhostVDPAState *s = opaque;
-    size_t in_len, dev_written;
+    size_t in_len;
     virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
     /* out and in buffers sent to the device */
     struct iovec dev_buffers[2] = {
@@ -387,7 +433,6 @@ static int 
vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,
         .iov_base = &status,
         .iov_len = sizeof(status),
     };
-    int r = -EINVAL;
     bool ok;
 
     ok = vhost_vdpa_net_cvq_map_elem(s, elem, &dev_buffers[0].iov_len);
@@ -400,27 +445,7 @@ static int 
vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq,
         goto out;
     }
 
-    r = vhost_svq_add(svq, &dev_buffers[0], 1, &dev_buffers[1], 1, elem);
-    if (unlikely(r != 0)) {
-        if (unlikely(r == -ENOSPC)) {
-            qemu_log_mask(LOG_GUEST_ERROR, "%s: No space on device queue\n",
-                          __func__);
-        }
-        goto out;
-    }
-
-    /*
-     * We can poll here since we've had BQL from the time we sent the
-     * descriptor. Also, we need to take the answer before SVQ pulls by itself,
-     * when BQL is released
-     */
-    dev_written = vhost_svq_poll(svq);
-    if (unlikely(dev_written < sizeof(status))) {
-        error_report("Insufficient written data (%zu)", dev_written);
-        goto out;
-    }
-
-    memcpy(&status, dev_buffers[1].iov_base, sizeof(status));
+    status = vhost_vdpa_net_cvq_add(s, dev_buffers[0].iov_len);
     if (status != VIRTIO_NET_OK) {
         goto out;
     }
@@ -445,7 +470,7 @@ out:
     if (dev_buffers[1].iov_base) {
         vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, dev_buffers[1].iov_base);
     }
-    return r;
+    return 0;
 }
 
 static const VhostShadowVirtqueueOps vhost_vdpa_net_svq_ops = {
-- 
2.31.1