[PATCH 04/40] vdpa: piggyback desc_group index when probing isolated cvq

[Si-Wei Liu <si-wei.liu@oracle.com>]

Same as the previous commit, but do it for cvq instead of data vqs.

Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>
---
 net/vhost-vdpa.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 0cf3147..cb5705d 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -1601,16 +1601,19 @@ static const VhostShadowVirtqueueOps vhost_vdpa_net_svq_ops = {
 };
 
 /**
- * Probe if CVQ is isolated
+ * Probe if CVQ is isolated, and piggyback its descriptor group
+ * index if supported
  *
  * @device_fd         The vdpa device fd
  * @features          Features offered by the device.
  * @cvq_index         The control vq pair index
+ * @desc_grpidx       The CVQ's descriptor group index to return
  *
- * Returns <0 in case of failure, 0 if false and 1 if true.
+ * Returns <0 in case of failure, 0 if false and 1 if true (isolated).
  */
 static int vhost_vdpa_probe_cvq_isolation(int device_fd, uint64_t features,
-                                          int cvq_index, Error **errp)
+                                          int cvq_index, int64_t *desc_grpidx,
+                                          Error **errp)
 {
     uint64_t backend_features;
     int64_t cvq_group;
@@ -1667,6 +1670,13 @@ static int vhost_vdpa_probe_cvq_isolation(int device_fd, uint64_t features,
         goto out;
     }
 
+    if (backend_features & BIT_ULL(VHOST_BACKEND_F_DESC_ASID)) {
+        int64_t desc_group = vhost_vdpa_get_vring_desc_group(device_fd,
+                                                             cvq_index, errp);
+        if (likely(desc_group >= 0) && desc_group != cvq_group)
+            *desc_grpidx = desc_group;
+    }
+
     for (int i = 0; i < cvq_index; ++i) {
         int64_t group = vhost_vdpa_get_vring_group(device_fd, i, errp);
         if (unlikely(group < 0)) {
@@ -1685,6 +1695,8 @@ static int vhost_vdpa_probe_cvq_isolation(int device_fd, uint64_t features,
 out:
     status = 0;
     ioctl(device_fd, VHOST_VDPA_SET_STATUS, &status);
+    status = VIRTIO_CONFIG_S_ACKNOWLEDGE | VIRTIO_CONFIG_S_DRIVER;
+    ioctl(device_fd, VHOST_VDPA_SET_STATUS, &status);
     return r;
 }
 
@@ -1791,6 +1803,7 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
                                        Error **errp)
 {
     NetClientState *nc = NULL;
+    int64_t desc_group = -1;
     VhostVDPAState *s;
     int ret = 0;
     assert(name);
@@ -1802,7 +1815,7 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
     } else {
         cvq_isolated = vhost_vdpa_probe_cvq_isolation(vdpa_device_fd, features,
                                                       queue_pair_index * 2,
-                                                      errp);
+                                                      &desc_group, errp);
         if (unlikely(cvq_isolated < 0)) {
             return NULL;
         }
-- 
1.8.3.1