Re: [Qemu-devel] [RFC PATCH v2 03/10] Colo-proxy: add colo-proxy framework

[Zhang Chen]

On 02/20/2016 03:57 AM, Dr. David Alan Gilbert wrote:
> * Zhang Chen (address@hidden) wrote:
> > From: zhangchen <address@hidden>
> >
> > +static void colo_proxy_setup(NetFilterState *nf, Error **errp)
> > +{
> > +    COLOProxyState *s = FILTER_COLO_PROXY(nf);
> > +
> > +    if (!s->addr) {
> > +        error_setg(errp, "filter colo_proxy needs 'addr' property set!");
> > +        return;
> > +    }
> > +
> > +    if (nf->direction != NET_FILTER_DIRECTION_ALL) {
> > +        error_setg(errp, "colo need queue all packet,"
> > +                        "please startup colo-proxy with queue=all\n");
> > +        return;
> > +    }
> > +
> > +    s->sockfd = -1;
> > +    s->hashtable_size = 0;
> > +    colo_do_checkpoint = false;
> > +    qemu_event_init(&s->need_compare_ev, false);
> > +
> > +    s->incoming_queue = qemu_new_net_queue(qemu_netfilter_pass_to_next, nf);
> I found that I had to be careful that this queue got flushed.  If the packet
> can't be sent immediately, then the packet only gets sent if another
> packet is added to the queue later.  I added a state change notifier to
> flush it when the VM started running (this is more of a problem in my hybrid
> mode case).
>
> Note also that the queue is not protected by locks; so take care since packets
> are sent from both the comparison thread and the colo thread (when it flushes)
> and I think it's read by the main thread as well potentially as packets are 
> sent.
>
> Dave

Hi, Dave.
Thanks for your review, I will pay attention to this problem in the 
following modules.
and We have split colo-proxy to filter-mirror, filter-redirector, 
filter-rewriter and
colo-compare about jason's comments. The detail please look at the 
discussion
about "[RFC PATCH v2 00/10] Add colo-proxy based on netfilter" . If you 
have time,
please review it.

Thanks
zhangchen

> > +    colo_conn_hash = g_hash_table_new_full(connection_key_hash,
> > +                                           connection_key_equal,
> > +                                           g_free,
> > +                                           connection_destroy);
> > +    g_queue_init(&s->conn_list);
> > +}
> > +
> > +static void colo_proxy_class_init(ObjectClass *oc, void *data)
> > +{
> > +    NetFilterClass *nfc = NETFILTER_CLASS(oc);
> > +
> > +    nfc->setup = colo_proxy_setup;
> > +    nfc->cleanup = colo_proxy_cleanup;
> > +    nfc->receive_iov = colo_proxy_receive_iov;
> > +}
> > +
> > +static int colo_proxy_get_mode(Object *obj, Error **errp)
> > +{
> > +    COLOProxyState *s = FILTER_COLO_PROXY(obj);
> > +
> > +    return s->colo_mode;
> > +}
> > +
> > +static void
> > +colo_proxy_set_mode(Object *obj, int mode, Error **errp)
> > +{
> > +    COLOProxyState *s = FILTER_COLO_PROXY(obj);
> > +
> > +    s->colo_mode = mode;
> > +}
> > +
> > +static char *colo_proxy_get_addr(Object *obj, Error **errp)
> > +{
> > +    COLOProxyState *s = FILTER_COLO_PROXY(obj);
> > +
> > +    return g_strdup(s->addr);
> > +}
> > +
> > +static void
> > +colo_proxy_set_addr(Object *obj, const char *value, Error **errp)
> > +{
> > +    COLOProxyState *s = FILTER_COLO_PROXY(obj);
> > +    g_free(s->addr);
> > +    s->addr = g_strdup(value);
> > +    if (!s->addr) {
> > +        error_setg(errp, "colo_proxy needs 'addr'"
> > +                     "property set!");
> > +        return;
> > +    }
> > +}
> > +
> > +static void colo_proxy_init(Object *obj)
> > +{
> > +    object_property_add_enum(obj, "mode", "COLOMode", COLOMode_lookup,
> > +                             colo_proxy_get_mode, colo_proxy_set_mode, NULL);
> > +    object_property_add_str(obj, "addr", colo_proxy_get_addr,
> > +                            colo_proxy_set_addr, NULL);
> > +}
> > +
> > +static void colo_proxy_fini(Object *obj)
> > +{
> > +    COLOProxyState *s = FILTER_COLO_PROXY(obj);
> > +    g_free(s->addr);
> > +}
> > +
> > +static const TypeInfo colo_proxy_info = {
> > +    .name = TYPE_FILTER_COLO_PROXY,
> > +    .parent = TYPE_NETFILTER,
> > +    .class_init = colo_proxy_class_init,
> > +    .instance_init = colo_proxy_init,
> > +    .instance_finalize = colo_proxy_fini,
> > +    .instance_size = sizeof(COLOProxyState),
> > +};
> > +
> > +static void register_types(void)
> > +{
> > +    type_register_static(&colo_proxy_info);
> > +}
> > +
> > +type_init(register_types);
> > diff --git a/net/colo-proxy.h b/net/colo-proxy.h
> > new file mode 100644
> > index 0000000..affc117
> > --- /dev/null
> > +++ b/net/colo-proxy.h
> > @@ -0,0 +1,24 @@
> > +/*
> > + * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
> > + * (a.k.a. Fault Tolerance or Continuous Replication)
> > + *
> > + * Copyright (c) 2015 HUAWEI TECHNOLOGIES CO., LTD.
> > + * Copyright (c) 2015 FUJITSU LIMITED
> > + * Copyright (c) 2015 Intel Corporation
> > + *
> > + * Author: Zhang Chen <address@hidden>
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2 or
> > + * later.  See the COPYING file in the top-level directory.
> > + */
> > +
> > +
> > +#ifndef QEMU_COLO_PROXY_H
> > +#define QEMU_COLO_PROXY_H
> > +
> > +int colo_proxy_start(int mode);
> > +void colo_proxy_stop(int mode);
> > +int colo_proxy_do_checkpoint(int mode);
> > +bool colo_proxy_query_checkpoint(void);
> > +
> > +#endif /* QEMU_COLO_PROXY_H */
> > --
> > 1.9.1
> --
> Dr. David Alan Gilbert / address@hidden / Manchester, UK
>
>
> .

--
Thanks
zhangchen