[PATCH v4 2/4] vhost-vdpa: add callback function for configure interrupt

[Cindy Lu]

Add call back function for configure interrupt.
Set the notifier's fd to the kernel driver when vdpa start.
also set -1 while vdpa stop. then the kernel will release
the related resource

Signed-off-by: Cindy Lu <lulu@redhat.com>
---
 hw/virtio/trace-events            |  2 ++
 hw/virtio/vhost-vdpa.c            | 40 +++++++++++++++++++++++++++++--
 include/hw/virtio/vhost-backend.h |  4 ++++
 3 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 2060a144a2..6710835b46 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -52,6 +52,8 @@ vhost_vdpa_set_vring_call(void *dev, unsigned int index, int 
fd) "dev: %p index:
 vhost_vdpa_get_features(void *dev, uint64_t features) "dev: %p features: 
0x%"PRIx64
 vhost_vdpa_set_owner(void *dev) "dev: %p"
 vhost_vdpa_vq_get_addr(void *dev, void *vq, uint64_t desc_user_addr, uint64_t 
avail_user_addr, uint64_t used_user_addr) "dev: %p vq: %p desc_user_addr: 
0x%"PRIx64" avail_user_addr: 0x%"PRIx64" used_user_addr: 0x%"PRIx64
+vhost_vdpa_set_config_call(void *dev, int *fd)"dev: %p fd: %p"
+
 
 # virtio.c
 virtqueue_alloc_element(void *elem, size_t sz, unsigned in_num, unsigned 
out_num) "elem %p size %zd in_num %u out_num %u"
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 01d2101d09..bde32eefe7 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -467,20 +467,47 @@ static int vhost_vdpa_get_config(struct vhost_dev *dev, 
uint8_t *config,
     }
     return ret;
  }
-
+static void vhost_vdpa_config_notify_start(struct vhost_dev *dev,
+                                struct VirtIODevice *vdev, bool start)
+{
+    int fd = 0;
+    int r = 0;
+    if (!(dev->features & (0x1ULL << VIRTIO_NET_F_STATUS))) {
+        return;
+    }
+    if (start) {
+        fd = event_notifier_get_fd(&vdev->config_notifier);
+        r = dev->vhost_ops->vhost_set_config_call(dev, &fd);
+     /*set the fd call back to vdpa driver*/
+        if (!r) {
+            vdev->use_config_notifier = VIRTIO_CONFIG_WORK;
+            event_notifier_set(&vdev->config_notifier);
+            info_report("vhost_vdpa_config_notify start!");
+      }
+    } else {
+        fd = -1;
+        vdev->use_config_notifier = VIRTIO_CONFIG_STOP;
+        r = dev->vhost_ops->vhost_set_config_call(dev, &fd);
+    }
+    return;
+}
 static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
 {
     struct vhost_vdpa *v = dev->opaque;
     trace_vhost_vdpa_dev_start(dev, started);
+    VirtIODevice *vdev = dev->vdev;
+
     if (started) {
         uint8_t status = 0;
         memory_listener_register(&v->listener, &address_space_memory);
         vhost_vdpa_set_vring_ready(dev);
         vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
         vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &status);
-
+        /*set the configure interrupt call back*/
+        vhost_vdpa_config_notify_start(dev, vdev, true);
         return !(status & VIRTIO_CONFIG_S_DRIVER_OK);
     } else {
+        vhost_vdpa_config_notify_start(dev, vdev, false);
         vhost_vdpa_reset_device(dev);
         vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
                                    VIRTIO_CONFIG_S_DRIVER);
@@ -546,6 +573,14 @@ static int vhost_vdpa_set_vring_call(struct vhost_dev *dev,
     return vhost_vdpa_call(dev, VHOST_SET_VRING_CALL, file);
 }
 
+static int vhost_vdpa_set_config_call(struct vhost_dev *dev,
+                                       int *fd)
+{
+    trace_vhost_vdpa_set_config_call(dev, fd);
+
+    return vhost_vdpa_call(dev, VHOST_VDPA_SET_CONFIG_CALL, fd);
+}
+
 static int vhost_vdpa_get_features(struct vhost_dev *dev,
                                      uint64_t *features)
 {
@@ -611,4 +646,5 @@ const VhostOps vdpa_ops = {
         .vhost_get_device_id = vhost_vdpa_get_device_id,
         .vhost_vq_get_addr = vhost_vdpa_vq_get_addr,
         .vhost_force_iommu = vhost_vdpa_force_iommu,
+        .vhost_set_config_call = vhost_vdpa_set_config_call,
 };
diff --git a/include/hw/virtio/vhost-backend.h 
b/include/hw/virtio/vhost-backend.h
index 8a6f8e2a7a..1a2fee8994 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -125,6 +125,9 @@ typedef int (*vhost_get_device_id_op)(struct vhost_dev 
*dev, uint32_t *dev_id);
 
 typedef bool (*vhost_force_iommu_op)(struct vhost_dev *dev);
 
+typedef int (*vhost_set_config_call_op)(struct vhost_dev *dev,
+                                       int *fd);
+
 typedef struct VhostOps {
     VhostBackendType backend_type;
     vhost_backend_init vhost_backend_init;
@@ -170,6 +173,7 @@ typedef struct VhostOps {
     vhost_vq_get_addr_op  vhost_vq_get_addr;
     vhost_get_device_id_op vhost_get_device_id;
     vhost_force_iommu_op vhost_force_iommu;
+    vhost_set_config_call_op vhost_set_config_call;
 } VhostOps;
 
 extern const VhostOps user_ops;
-- 
2.21.3