Re: [RFC v2 3/9] virtio_net: introduce vhost_set_state

[Jason Wang <jasowang@redhat.com>]

On 2020/5/9 上午12:32, Cindy Lu wrote:
> Introduce a function to set the state to the vhost driver.
> vDPA need to sync the driver's state to NIC


Let's split this patch into two.

1) introduce vhost_set_state
2) make virtio-net use of vhost_set_state


>
> Signed-off-by: Cindy Lu <lulu@redhat.com>
> ---
>   hw/net/vhost_net.c                | 9 +++++++++
>   hw/net/virtio-net.c               | 9 +++++++++
>   include/hw/virtio/vhost-backend.h | 2 ++
>   include/net/vhost_net.h           | 2 +-
>   4 files changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index d1d421e3d9..63b2a85d6e 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -465,3 +465,12 @@ int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu)
>   
>       return vhost_ops->vhost_net_set_mtu(&net->dev, mtu);
>   }
> +int vhost_set_state(NetClientState *nc, uint8_t state)
> +{
> +    struct vhost_net *net = get_vhost_net(nc);
> +    struct vhost_dev *hdev = &net->dev;
> +        if (hdev->vhost_ops->vhost_set_state) {


Indentation looks wrong.


> +                return hdev->vhost_ops->vhost_set_state(hdev, state);
> +        }
> +    return 0;
> +}
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index db3d7c38e6..1bddb4b4af 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -206,6 +206,9 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
>       VirtIODevice *vdev = VIRTIO_DEVICE(n);
>       NetClientState *nc = qemu_get_queue(n->nic);
>       int queues = n->multiqueue ? n->max_queues : 1;
> +    NetClientState *peer = qemu_get_peer(nc, 0);
> +    uint8_t status_set  = vdev->status ;
> +    uint8_t vhost_started_pre = n->vhost_started;
>   
>       if (!get_vhost_net(nc->peer)) {
>           return;
> @@ -245,6 +248,7 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
>                   return;
>               }
>           }
> +        status_set = status_set | VIRTIO_CONFIG_S_DRIVER_OK;
>   
>           n->vhost_started = 1;
>           r = vhost_net_start(vdev, n->nic->ncs, queues);
> @@ -252,11 +256,16 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
>               error_report("unable to start vhost net: %d: "
>                            "falling back on userspace virtio", -r);
>               n->vhost_started = 0;
> +            status_set = status_set & ~VIRTIO_CONFIG_S_DRIVER_OK;
>           }
>       } else {
>           vhost_net_stop(vdev, n->nic->ncs, queues);
> +        status_set = status_set & ~VIRTIO_CONFIG_S_DRIVER_OK;
>           n->vhost_started = 0;
>       }
> +    if (vhost_started_pre != n->vhost_started) {
> +            vhost_set_state(peer, status_set);


Any reason why not just passing virtio device status to vhost-vdpa?


> +    }
>   }
>   
>   static int virtio_net_set_vnet_endian_one(VirtIODevice *vdev,
> diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
> index 6f6670783f..f823055167 100644
> --- a/include/hw/virtio/vhost-backend.h
> +++ b/include/hw/virtio/vhost-backend.h
> @@ -112,6 +112,7 @@ typedef int (*vhost_get_inflight_fd_op)(struct vhost_dev *dev,
>   typedef int (*vhost_set_inflight_fd_op)(struct vhost_dev *dev,
>                                           struct vhost_inflight *inflight);
>   
> +typedef int (*vhost_set_state_op)(struct vhost_dev *dev, uint8_t state);


Need document what's the meaning of state here, is it e.g virtio device 
status? If yes, is it better to rename it to vhost_set_status()?

Thanks


>   typedef struct VhostOps {
>       VhostBackendType backend_type;
>       vhost_backend_init vhost_backend_init;
> @@ -152,6 +153,7 @@ typedef struct VhostOps {
>       vhost_backend_mem_section_filter_op vhost_backend_mem_section_filter;
>       vhost_get_inflight_fd_op vhost_get_inflight_fd;
>       vhost_set_inflight_fd_op vhost_set_inflight_fd;
> +    vhost_set_state_op vhost_set_state;
>   } VhostOps;
>   
>   extern const VhostOps user_ops;
> diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
> index 77e47398c4..6548a5a105 100644
> --- a/include/net/vhost_net.h
> +++ b/include/net/vhost_net.h
> @@ -39,5 +39,5 @@ int vhost_set_vring_enable(NetClientState * nc, int enable);
>   uint64_t vhost_net_get_acked_features(VHostNetState *net);
>   
>   int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu);
> -
> +int vhost_set_state(NetClientState *nc, uint8_t state);
>   #endif