Re: [PATCH v5 4/6] vhost-vdpa: add support for configure interrupt

[Jason Wang]

在 2021/4/8 下午5:38, Cindy Lu 写道:
Add support 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 <l...@redhat.com>
---
  hw/virtio/vhost-vdpa.c | 26 +++++++++++++++++++++++++-
  1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 9ba2a2bed4..7825366f64 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -467,11 +467,33 @@ static int vhost_vdpa_get_config(struct vhost_dev *dev, 
uint8_t *config,
      }
      return ret;
   }
-


Let's keep this blank line.


+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);


So you introduce a general vhost ops but it's call by devic specific 
code (vhost-vdpa).

Any reason that we don't do that in vhost_dev_start/vhost_dev_stop?

Thanks


+        if (!r) {
+            vdev->use_config_notifier = true;
+            event_notifier_set(&vdev->config_notifier);
+        }
+    } else {
+        fd = -1;
+        vdev->use_config_notifier = false;
+        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);
@@ -479,8 +501,10 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, 
bool started)
          vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
          vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &status);
  
+        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);