[RFC PATCH v9 05/23] vhost: Add ShadowVirtQueueStart operation

[Eugenio Pérez]

It allows to run commands at SVQ start.

Signed-off-by: Eugenio Pérez <epere...@redhat.com>
---
 hw/virtio/vhost-shadow-virtqueue.h | 18 +++++++++++++++++-
 hw/virtio/vhost-shadow-virtqueue.c |  8 +++++++-
 hw/virtio/vhost-vdpa.c             | 17 ++++++++++++++++-
 3 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/hw/virtio/vhost-shadow-virtqueue.h 
b/hw/virtio/vhost-shadow-virtqueue.h
index c132c994e9..91c31715d9 100644
--- a/hw/virtio/vhost-shadow-virtqueue.h
+++ b/hw/virtio/vhost-shadow-virtqueue.h
@@ -15,6 +15,14 @@
 #include "standard-headers/linux/vhost_types.h"
 #include "hw/virtio/vhost-iova-tree.h"
 
+typedef struct VhostShadowVirtqueue VhostShadowVirtqueue;
+typedef int (*ShadowVirtQueueStart)(VhostShadowVirtqueue *svq,
+                                    void *opaque);
+
+typedef struct VhostShadowVirtqueueOps {
+    ShadowVirtQueueStart start;
+} VhostShadowVirtqueueOps;
+
 /* Shadow virtqueue to relay notifications */
 typedef struct VhostShadowVirtqueue {
     /* Shadow vring */
@@ -59,6 +67,12 @@ typedef struct VhostShadowVirtqueue {
      */
     uint16_t *desc_next;
 
+    /* Caller callbacks */
+    const VhostShadowVirtqueueOps *ops;
+
+    /* Caller callbacks opaque */
+    void *ops_opaque;
+
     /* Next head to expose to the device */
     uint16_t shadow_avail_idx;
 
@@ -85,7 +99,9 @@ void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice 
*vdev,
                      VirtQueue *vq);
 void vhost_svq_stop(VhostShadowVirtqueue *svq);
 
-VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree *iova_tree);
+VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree *iova_tree,
+                                    const VhostShadowVirtqueueOps *ops,
+                                    void *ops_opaque);
 
 void vhost_svq_free(gpointer vq);
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(VhostShadowVirtqueue, vhost_svq_free);
diff --git a/hw/virtio/vhost-shadow-virtqueue.c 
b/hw/virtio/vhost-shadow-virtqueue.c
index 2939f4a243..be64e0b85c 100644
--- a/hw/virtio/vhost-shadow-virtqueue.c
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -626,12 +626,16 @@ void vhost_svq_stop(VhostShadowVirtqueue *svq)
  * shadow methods and file descriptors.
  *
  * @iova_tree: Tree to perform descriptors translations
+ * @ops: SVQ owner callbacks
+ * @ops_opaque: ops opaque pointer
  *
  * Returns the new virtqueue or NULL.
  *
  * In case of error, reason is reported through error_report.
  */
-VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree *iova_tree)
+VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree *iova_tree,
+                                    const VhostShadowVirtqueueOps *ops,
+                                    void *ops_opaque)
 {
     g_autofree VhostShadowVirtqueue *svq = g_new0(VhostShadowVirtqueue, 1);
     int r;
@@ -653,6 +657,8 @@ VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree 
*iova_tree)
     event_notifier_init_fd(&svq->svq_kick, VHOST_FILE_UNBIND);
     event_notifier_set_handler(&svq->hdev_call, vhost_svq_handle_call);
     svq->iova_tree = iova_tree;
+    svq->ops = ops;
+    svq->ops_opaque = ops_opaque;
     return g_steal_pointer(&svq);
 
 err_init_hdev_call:
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index de76128030..69cfaf05d6 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -418,7 +418,8 @@ static int vhost_vdpa_init_svq(struct vhost_dev *hdev, 
struct vhost_vdpa *v,
 
     shadow_vqs = g_ptr_array_new_full(hdev->nvqs, vhost_svq_free);
     for (unsigned n = 0; n < hdev->nvqs; ++n) {
-        g_autoptr(VhostShadowVirtqueue) svq = vhost_svq_new(v->iova_tree);
+        g_autoptr(VhostShadowVirtqueue) svq = vhost_svq_new(v->iova_tree, NULL,
+                                                            NULL);
 
         if (unlikely(!svq)) {
             error_setg(errp, "Cannot create svq %u", n);
@@ -1122,6 +1123,20 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, 
bool started)
         if (unlikely(r)) {
             return r;
         }
+
+        if (v->shadow_vqs_enabled) {
+            for (unsigned i = 0; i < v->shadow_vqs->len; ++i) {
+                VhostShadowVirtqueue *svq = g_ptr_array_index(v->shadow_vqs,
+                                                              i);
+                if (svq->ops) {
+                    r = svq->ops->start(svq, svq->ops_opaque);
+                    if (unlikely(r)) {
+                        return r;
+                    }
+                }
+            }
+        }
+
         vhost_vdpa_set_vring_ready(dev);
     } else {
         vhost_vdpa_reset_device(dev);
-- 
2.31.1