Re: [PATCH v4 6/7] vdpa: Add virtio-net mac address via CVQ at start

[Jason Wang <jasowang@redhat.com>]

在 2022/7/22 19:12, Eugenio Pérez 写道:
> This is needed so the destination vdpa device see the same state a the
> guest set in the source.
>
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> ---
>   net/vhost-vdpa.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 61 insertions(+)
>
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index 61516b1432..3e15a42c35 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -365,10 +365,71 @@ static virtio_net_ctrl_ack vhost_vdpa_net_cvq_add(VhostShadowVirtqueue *svq,
>       return VIRTIO_NET_OK;
>   }
>   
> +static int vhost_vdpa_net_start(NetClientState *nc)
> +{
> +    VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
> +    struct vhost_vdpa *v = &s->vhost_vdpa;
> +    VirtIONet *n;
> +    uint64_t features;
> +    VhostShadowVirtqueue *svq;
> +
> +    assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
> +
> +    if (!v->shadow_vqs_enabled) {
> +        return 0;
> +    }
> +
> +    if (v->dev->nvqs != 1 &&
> +        v->dev->vq_index + v->dev->nvqs != v->dev->vq_index_end) {
> +        /* Only interested in CVQ */
> +        return 0;
> +    }


I'd have a dedicated NetClientInfo for cvq.


> +
> +    n = VIRTIO_NET(v->dev->vdev);
> +    features = v->dev->vdev->host_features;
> +    svq = g_ptr_array_index(v->shadow_vqs, 0);
> +    if (features & BIT_ULL(VIRTIO_NET_F_CTRL_MAC_ADDR)) {
> +        const struct virtio_net_ctrl_hdr ctrl = {
> +            .class = VIRTIO_NET_CTRL_MAC,
> +            .cmd = VIRTIO_NET_CTRL_MAC_ADDR_SET,
> +        };
> +        uint8_t mac[6];
> +        const struct iovec out[] = {
> +            {
> +                .iov_base = (void *)&ctrl,
> +                .iov_len = sizeof(ctrl),
> +            },{
> +                .iov_base = mac,
> +                .iov_len = sizeof(mac),
> +            },
> +        };
> +        struct iovec dev_buffers[2] = {
> +            { .iov_base = s->cvq_cmd_out_buffer },
> +            { .iov_base = s->cvq_cmd_in_buffer },
> +        };
> +        bool ok;
> +        virtio_net_ctrl_ack state;
> +
> +        ok = vhost_vdpa_net_cvq_map_sg(s, out, ARRAY_SIZE(out), dev_buffers);


To speed up the state recovery, can we map those buffers during svq start?

Thanks


> +        if (unlikely(!ok)) {
> +            return -1;
> +        }
> +
> +        memcpy(mac, n->mac, sizeof(mac));
> +        state = vhost_vdpa_net_cvq_add(svq, dev_buffers);
> +        vhost_vdpa_cvq_unmap_buf(v, dev_buffers[0].iov_base);
> +        vhost_vdpa_cvq_unmap_buf(v, dev_buffers[1].iov_base);
> +        return state == VIRTIO_NET_OK ? 0 : 1;
> +    }
> +
> +    return 0;
> +}
> +
>   static NetClientInfo net_vhost_vdpa_info = {
>           .type = NET_CLIENT_DRIVER_VHOST_VDPA,
>           .size = sizeof(VhostVDPAState),
>           .receive = vhost_vdpa_receive,
> +        .start = vhost_vdpa_net_start,
>           .cleanup = vhost_vdpa_cleanup,
>           .has_vnet_hdr = vhost_vdpa_has_vnet_hdr,
>           .has_ufo = vhost_vdpa_has_ufo,