Re: [Qemu-devel] [PATCH V4 02/12] net/filter-mirror.c: Add new option to enable vnet support for filter-mirror

[Jason Wang <jasowang@redhat.com>]

On 2017年05月12日 09:41, Zhang Chen wrote:
> We add the vnet_hdr option for filter-mirror, default is disable.
> If you use virtio-net-pci net driver, please enable it.
> You can use it for example:
> -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0,vnet_hdr=on
>
> Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
> ---
>   net/filter-mirror.c | 34 ++++++++++++++++++++++++++++++++++
>   qemu-options.hx     |  5 +++--
>   2 files changed, 37 insertions(+), 2 deletions(-)
>
> diff --git a/net/filter-mirror.c b/net/filter-mirror.c
> index 72fa7c2..3766414 100644
> --- a/net/filter-mirror.c
> +++ b/net/filter-mirror.c
> @@ -38,6 +38,7 @@ typedef struct MirrorState {
>       NetFilterState parent_obj;
>       char *indev;
>       char *outdev;
> +    bool vnet_hdr;
>       CharBackend chr_in;
>       CharBackend chr_out;
>       SocketReadState rs;
> @@ -308,6 +309,13 @@ static char *filter_mirror_get_outdev(Object *obj, Error **errp)
>       return g_strdup(s->outdev);
>   }
>   
> +static char *filter_mirror_get_vnet_hdr(Object *obj, Error **errp)
> +{
> +    MirrorState *s = FILTER_MIRROR(obj);
> +
> +    return s->vnet_hdr ? g_strdup("on") : g_strdup("off");
> +}
> +
>   static void
>   filter_mirror_set_outdev(Object *obj, const char *value, Error **errp)
>   {
> @@ -322,6 +330,21 @@ filter_mirror_set_outdev(Object *obj, const char *value, Error **errp)
>       }
>   }
>   
> +static void filter_mirror_set_vnet_hdr(Object *obj,
> +                                       const char *value,
> +                                       Error **errp)
> +{
> +    MirrorState *s = FILTER_MIRROR(obj);
> +
> +    if (strcmp(value, "on") && strcmp(value, "off")) {
> +        error_setg(errp, "Invalid value for filter-mirror vnet_hdr, "
> +                         "should be 'on' or 'off'");
> +        return;
> +    }
> +
> +    s->vnet_hdr = !strcmp(value, "on");
> +}
> +
>   static char *filter_redirector_get_outdev(Object *obj, Error **errp)
>   {
>       MirrorState *s = FILTER_REDIRECTOR(obj);
> @@ -340,8 +363,19 @@ filter_redirector_set_outdev(Object *obj, const char *value, Error **errp)
>   
>   static void filter_mirror_init(Object *obj)
>   {
> +    MirrorState *s = FILTER_MIRROR(obj);
> +
>       object_property_add_str(obj, "outdev", filter_mirror_get_outdev,
>                               filter_mirror_set_outdev, NULL);
> +
> +    /*
> +     * The vnet_hdr is disabled by default, if you want to enable
> +     * this option, you must enable all the option on related modules
> +     * (like other filter or colo-compare).
> +     */
> +    s->vnet_hdr = false;
> +    object_property_add_str(obj, "vnet_hdr", filter_mirror_get_vnet_hdr,
> +                             filter_mirror_set_vnet_hdr, NULL);
>   }

We'd better squash this into patch 3 and even after the changes for 
net_fill_rstate().

>   
>   static void filter_redirector_init(Object *obj)
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 70c0ded..1e08481 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -4024,10 +4024,11 @@ queue @var{all|rx|tx} is an option that can be applied to any netfilter.
>   @option{tx}: the filter is attached to the transmit queue of the netdev,
>                where it will receive packets sent by the netdev.
>   
> -@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid}[,queue=@var{all|rx|tx}]
> +@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},vnet_hdr=@var{on|off}[,queue=@var{all|rx|tx}]
>   
>   filter-mirror on netdev @var{netdevid},mirror net packet to chardev
> -@var{chardevid}
> +@var{chardevid}, if vnet_hdr = on, filter-mirror will mirror packet
> +with vnet_hdr_len.

As pointed by Eric, we'd better keep the long line here.

Thanks

>   
>   @item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},
>   outdev=@var{chardevid}[,queue=@var{all|rx|tx}]