Re: [Qemu-devel] [PATCH v11 12/12] netfilter: add multiqueue support

[Yang Hongyang]

On 09/22/2015 03:36 PM, Jason Wang wrote:
> On 09/16/2015 08:16 PM, Yang Hongyang wrote:
> > From: Yang Hongyang <address@hidden>
> >
> > add multiqueue support, if there's multiqueue, we add multi netfilter
> > objects, other netfilter objects is the child of the first added netfilter
> > object. So when we delete a netfilter, the other netfilter objects we
> > added will be automatically deleted.
> >
> > Signed-off-by: Yang Hongyang <address@hidden>
> > ---
> > v11: initial patch
> > ---
> >   net/filter.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-----
> >   1 file changed, 79 insertions(+), 7 deletions(-)
> >
> > diff --git a/net/filter.c b/net/filter.c
> > index aea619a..cc27528 100644
> > --- a/net/filter.c
> > +++ b/net/filter.c
> > @@ -142,16 +142,25 @@ static void netfilter_finalize(Object *obj)
> >       g_free(nf->name);
> >   }
> >
> > +static void proptb_free_val_func(gpointer data)
> > +{
> > +    g_free(data);
> > +}
> > +
> >   static void netfilter_complete(UserCreatable *uc, Error **errp)
> >   {
> > -    NetFilterState *nf = NETFILTER(uc);
> > +    NetFilterState *nf = NETFILTER(uc), *nfq = NULL;
> >       NetClientState *ncs[MAX_QUEUE_NUM];
> > -    NetFilterClass *nfc = NETFILTER_GET_CLASS(uc);
> > -    int queues;
> > +    NetFilterClass *nfc = NETFILTER_GET_CLASS(uc), *nfqc = NULL;
> > +    int queues, i;
> >       Error *local_err = NULL;
> > -    char *str, *info;
> > +    char *str, *info, *name;
> >       ObjectProperty *prop;
> >       StringOutputVisitor *ov;
> > +    Object *obj = NULL;
> > +    GHashTable *proptable = NULL;
> > +    GHashTableIter iter;
> > +    gpointer key, value;
> >
> >       if (!nf->netdev_id) {
> >           error_setg(errp, "Parameter 'netdev' is required");
> > @@ -165,9 +174,6 @@ static void netfilter_complete(UserCreatable *uc, Error 
> > **errp)
> >           error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "netdev",
> >                      "a network backend id");
> >           return;
> > -    } else if (queues > 1) {
> > -        error_setg(errp, "Multi queue is not supported");
> > -        return;
> >       }
> >
> >       if (get_vhost_net(ncs[0])) {
> > @@ -187,6 +193,17 @@ static void netfilter_complete(UserCreatable *uc, Error 
> > **errp)
> >       }
> >       QTAILQ_INSERT_TAIL(&nf->netdev->filters, nf, next);
> >
> > +    if (queues > 1) {
> > +        /*
> > +         * Store the properties of the filter except "type" property.
> > +         * When there's multiqueue, we will create a new filter object
> > +         * of the same type and same properties. this hashtable is used
> > +         * to set newly created object properties.
> > +         */
> > +        proptable = g_hash_table_new_full(NULL, NULL, NULL,
> > +                                          proptb_free_val_func);
> > +    }
>
> I'm thinking whether or not duplicate all the properties in each
> netfilters is a good method. Maybe we can have a another ojbect with
> array of pointers to NetFilter objects embedded? Another question is
> whether or not we need to do this at this level. Maybe we can make the
> necessary Netfilter multiqueue aware. E.g let buffer filter to have
> multiqueue also? Then you may only need a single timer?

Sorry I don't get it at first. I also thought about make the buffer filter to
have multiqueue, but there comes problem, how to distinguish which queue
we should go in when receive the packet, we need to add a mechanism to
distinguish which queue belongs to which net client's queue, that will
be more complex, while current multiqueue implementation of net clients
is multiple net clients with the same name, current solution is the simplest
solution I can think of...

> > +
> >       /* generate info str */
> >       QTAILQ_FOREACH(prop, &OBJECT(nf)->properties, node) {
> >           if (!strcmp(prop->name, "type")) {
> > @@ -199,9 +216,64 @@ static void netfilter_complete(UserCreatable *uc, Error 
> > **errp)
> >           string_output_visitor_cleanup(ov);
> >           info = g_strdup_printf(",%s=%s", prop->name, str);
> >           g_strlcat(nf->info_str, info, sizeof(nf->info_str));
> > +        if (queues > 1) {
> > +            g_hash_table_insert(proptable, prop->name, g_strdup(str));
> > +        }
> >           g_free(str);
> >           g_free(info);
> >       }
> > +
> > +    for (i = 1; i < queues; i++) {
> > +        obj = object_new(object_get_typename(OBJECT(nf)));
> > +        /* set filter properties */
> > +        nfq = NETFILTER(obj);
> > +        nfq->name = g_strdup(nf->name);
> > +        nfq->netdev = ncs[i];
> > +        snprintf(nfq->info_str, sizeof(nfq->info_str), "%s", nf->info_str);
> > +
> > +        g_hash_table_iter_init(&iter, proptable);
> > +        while (g_hash_table_iter_next(&iter, &key, &value)) {
> > +            object_property_parse(obj, (char *)value, (char *)key, &local_err);
> > +            if (local_err) {
> > +                error_propagate(errp, local_err);
> > +                goto out;
> > +            }
> > +        }
> > +
> > +        /* add other queue's filter object as the first object's child */
> > +        name = g_strdup_printf("%s-queue-%d", nf->name, i);
> > +        object_property_add_child(OBJECT(nf), name, obj, &local_err);
> > +        g_free(name);
> > +        if (local_err) {
> > +            error_propagate(errp, local_err);
> > +            goto out;
> > +        }
> > +
> > +        /* setup filter */
> > +        nfqc = NETFILTER_GET_CLASS(obj);
> > +        if (nfqc->setup) {
> > +            nfqc->setup(nfq, &local_err);
> > +            if (local_err) {
> > +                error_propagate(errp, local_err);
> > +                goto out;
> > +            }
> > +        }
> > +        QTAILQ_INSERT_TAIL(&nfq->netdev->filters, nfq, next);
> > +        object_unref(obj);
> > +    }
> > +
> > +    if (proptable) {
> > +        g_hash_table_unref(proptable);
> > +    }
> > +    return;
> > +
> > +out:
>
> We may leak objects here.
>
> > +    if (proptable) {
> > +        g_hash_table_unref(proptable);
> > +    }
> > +    if (obj) {
> > +        object_unref(obj);
> > +    }
> >   }
> >
> >   static void netfilter_class_init(ObjectClass *oc, void *data)
>
> To reduce the review iterations, I suggest to drop the patch also.
> Multiqueue support could be another series on top.
>
> Thanks
>
>
> .

--
Thanks,
Yang.