Re: [Qemu-devel] [PATCH COLO-Frame v10 35/38] netfilter: Introduce a API to automatically add filter-buffer for each netdev

[zhanghailiang]

On 2015/11/3 20:57, Yang Hongyang wrote:
> On 2015年11月03日 19:56, zhanghailiang wrote:
> > Signed-off-by: zhanghailiang <address@hidden>
> > Cc: Jason Wang <address@hidden>
> > ---
> > v10: new patch
> > ---
> >   include/net/filter.h |  1 +
> >   include/net/net.h    |  3 ++
> >   net/filter-buffer.c  | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> >   net/net.c            | 20 +++++++++++++
> >   4 files changed, 108 insertions(+)
> >
> > diff --git a/include/net/filter.h b/include/net/filter.h
> > index 4499d60..b0954ba 100644
> > --- a/include/net/filter.h
> > +++ b/include/net/filter.h
> > @@ -75,5 +75,6 @@ ssize_t qemu_netfilter_pass_to_next(NetClientState *sender,
> >                                       void *opaque);
> >   void filter_buffer_release_all(void);
> >   void  filter_buffer_del_all_timers(void);
> > +void qemu_auto_add_filter_buffer(NetFilterDirection direction, Error **errp);
> >
> >   #endif /* QEMU_NET_FILTER_H */
> > diff --git a/include/net/net.h b/include/net/net.h
> > index 5c65c45..e32bd90 100644
> > --- a/include/net/net.h
> > +++ b/include/net/net.h
> > @@ -129,6 +129,9 @@ typedef void (*qemu_netfilter_foreach)(NetFilterState *nf, 
> > void *opaque,
> >                                          Error **errp);
> >   void qemu_foreach_netfilter(qemu_netfilter_foreach func, void *opaque,
> >                               Error **errp);
> > +typedef void (*qemu_netdev_foreach)(NetClientState *nc, void *opaque,
> > +                                    Error **errp);
> > +void qemu_foreach_netdev(qemu_netdev_foreach func, void *opaque, Error **errp);
> >   int qemu_can_send_packet(NetClientState *nc);
> >   ssize_t qemu_sendv_packet(NetClientState *nc, const struct iovec *iov,
> >                             int iovcnt);
> > diff --git a/net/filter-buffer.c b/net/filter-buffer.c
> > index 05313de..0dc1efb 100644
> > --- a/net/filter-buffer.c
> > +++ b/net/filter-buffer.c
> > @@ -15,6 +15,11 @@
> >   #include "qapi-visit.h"
> >   #include "qom/object.h"
> >   #include "net/net.h"
> > +#include "qapi/qmp/qdict.h"
> > +#include "qapi/qmp-output-visitor.h"
> > +#include "qapi/qmp-input-visitor.h"
> > +#include "monitor/monitor.h"
> > +
> >
> >   #define TYPE_FILTER_BUFFER "filter-buffer"
> >
> > @@ -185,6 +190,85 @@ void filter_buffer_del_all_timers(void)
> >       qemu_foreach_netfilter(filter_buffer_del_timer, NULL, NULL);
> >   }
> >
> > +static void netdev_add_filter_buffer(NetClientState *nc, void *opaque,
> > +                                     Error **errp)
> > +{
> > +    NetFilterState *nf;
> > +    bool found = false;
> > +
> > +    QTAILQ_FOREACH(nf, &nc->filters, next) {
> > +        if (!strcmp(object_get_typename(OBJECT(nf)), TYPE_FILTER_BUFFER)) {
> > +            found = true;
>
> What if a filter-buffer already attached to a netdev, but has interval
> set?
> Is this API really necessary?

We will jump this netdev, but remove its filter-buffer timer. Meanwhile, we will
release the packets all together in colo checkpoint process.
Besides, we should resume the timer after exit COLO. (We didn't do this in this 
version).

I don't know if it is a good idea to automatically add filter-buffer for the 
device
that not configured with it. But it is really reduce the complexity of testing.

> > +            break;
> > +        }
> > +    }
> > +
> > +    if (!found) {
> > +        QmpOutputVisitor *qov;
> > +        QmpInputVisitor *qiv;
> > +        Visitor *ov, *iv;
> > +        QObject *obj = NULL;
> > +        QDict *qdict;
> > +        void *dummy = NULL;
> > +        char *id = g_strdup_printf("%s-%s.0", nc->name, TYPE_FILTER_BUFFER);
> > +        char *queue = (char *) opaque;
> > +        bool auto_add = true;
> > +        Error *err = NULL;
> > +
> > +        qov = qmp_output_visitor_new();
> > +        ov = qmp_output_get_visitor(qov);
> > +        visit_start_struct(ov,  &dummy, NULL, NULL, 0, &err);
> > +        if (err) {
> > +            goto out;
> > +        }
> > +        visit_type_str(ov, &nc->name, "netdev", &err);
> > +        if (err) {
> > +            goto out;
> > +        }
> > +        visit_type_str(ov, &queue, "queue", &err);
> > +        if (err) {
> > +            goto out;
> > +        }
> > +        visit_type_bool(ov, &auto_add, "auto", &err);
> > +        if (err) {
> > +            goto out;
> > +        }
> > +        visit_end_struct(ov, &err);
> > +        if (err) {
> > +            goto out;
> > +        }
> > +        obj = qmp_output_get_qobject(qov);
> > +        g_assert(obj != NULL);
> > +        qdict = qobject_to_qdict(obj);
> > +        qmp_output_visitor_cleanup(qov);
> > +
> > +        qiv = qmp_input_visitor_new(obj);
> > +        iv = qmp_input_get_visitor(qiv);
> > +        object_add(TYPE_FILTER_BUFFER, id, qdict, iv, &err);
> > +        qmp_input_visitor_cleanup(qiv);
> > +        qobject_decref(obj);
> > +out:
> > +        g_free(id);
> > +        if (err) {
> > +            error_propagate(errp, err);
> > +        }
> > +    }
> > +}
> > +/*
> > +* This will be used by COLO or MC FT, for which they will need
> > +* to buffer all the packets of all VM's net devices, Here we check
> > +* and automatically add netfilter for netdev that doesn't attach any buffer
> > +* netfilter.
> > +*/
> > +void qemu_auto_add_filter_buffer(NetFilterDirection direction, Error **errp)
> > +{
> > +    char *queue = g_strdup(NetFilterDirection_lookup[direction]);
> > +
> > +    qemu_foreach_netdev(netdev_add_filter_buffer, queue,
> > +                                        errp);
> > +    g_free(queue);
> > +}
> > +
> >   static void filter_buffer_init(Object *obj)
> >   {
> >       object_property_add(obj, "interval", "int",
> > diff --git a/net/net.c b/net/net.c
> > index a333b01..4fbe0af 100644
> > --- a/net/net.c
> > +++ b/net/net.c
> > @@ -283,6 +283,26 @@ void qemu_foreach_netfilter(qemu_netfilter_foreach func, 
> > void *opaque,
> >       }
> >   }
> >
> > +void qemu_foreach_netdev(qemu_netdev_foreach func, void *opaque, Error **errp)
> > +{
> > +    NetClientState *nc;
> > +
> > +    QTAILQ_FOREACH(nc, &net_clients, next) {
> > +        if (nc->info->type == NET_CLIENT_OPTIONS_KIND_NIC) {
> > +            continue;
> > +        }
> > +        if (func) {
> > +            Error *local_err = NULL;
> > +
> > +            func(nc, opaque, &local_err);
> > +            if (local_err) {
> > +                error_propagate(errp, local_err);
> > +                return;
> > +            }
> > +        }
> > +    }
> > +}
> > +
> >   static void qemu_net_client_destructor(NetClientState *nc)
> >   {
> >       g_free(nc);