Re: [PATCH v3 5/5] vhost-vdpa: add callback function for configure interrupt

[Stefano Garzarella <sgarzare@redhat.com>]

On Tue, Jan 26, 2021 at 03:42:54PM +0800, Cindy Lu wrote:
>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            | 37 ++++++++++++++++++++++++++++++-
> include/hw/virtio/vhost-backend.h |  4 ++++
> 3 files changed, 42 insertions(+), 1 deletion(-)
>
>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..cc1d39d663 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, r;
>+    if (start) {
>+        fd = event_notifier_get_fd(&vdev->config_notifier);
>+        vdev->use_config_notifier = true;
>+     } else {
       ^
>+        fd = -1;
>+        vdev->use_config_notifier = false;
>+     }
       ^
>+     /*set the fd call back to vdpa driver*/
       ^
       It seems to me that there is an extra space in these places.

>+    r = dev->vhost_ops->vhost_set_config_call(dev, &fd);
>+    if (r) {
>+        vdev->use_config_notifier = false;
>+        info_report("vhost_vdpa_config_notify not started!");
>+    }
>+    /*active the config_notifier when vdev->use_config_notifier is true*/
>+    if ((vdev->use_config_notifier) && (start)) {
>+        event_notifier_set(&vdev->config_notifier);
>+    }
>+    return;
>
>+}

Here and also in other patches I would leave a new line between two 
functions.

> 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 +573,13 @@ 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 +645,5 @@ 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);
                                          ^
                                          One more space :-)

Thanks,
Stefano