Re: [Qemu-devel] [PATCH COLO-Frame v11 34/39] net/filter-buffer: Add default filter-buffer for each netdev

[Hailiang Zhang <zhang.zhanghailiang@huawei.com>]

On 2015/12/3 9:17, Wen Congyang wrote:
> On 11/24/2015 05:25 PM, zhanghailiang wrote:
>> We add each netdev a default filter-buffer, which will be used for COLO
>> or Micro-checkpoint to buffer VM's packets. The name of default filter-buffer
>> is 'nop'.
>> For the default filter-buffer, it will not buffer any packets in default.
>> So it has no side effect for the netdev.
>
> No, filter-buffer doesn't support vhost, so if you add default filter-buffer
> for each netdev, you can't use vhost.
>

Have you tested it ? Did the default filter-buffer break vhost ?
It's not supposed to break vhost, I will look into it. Thanks.

> Thanks
> Wen Congyang
>
>>
>> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
>> Cc: Jason Wang <jasowang@redhat.com>
>> Cc: Yang Hongyang <hongyang.yang@easystack.cn>
>> ---
>> v11:
>> - New patch
>> ---
>>   include/net/filter.h |  3 +++
>>   net/filter-buffer.c  | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>>   net/net.c            |  8 ++++++
>>   3 files changed, 85 insertions(+)
>>
>> diff --git a/include/net/filter.h b/include/net/filter.h
>> index 2deda36..01a7e90 100644
>> --- a/include/net/filter.h
>> +++ b/include/net/filter.h
>> @@ -74,4 +74,7 @@ ssize_t qemu_netfilter_pass_to_next(NetClientState *sender,
>>                                       int iovcnt,
>>                                       void *opaque);
>>
>> +void netdev_add_default_filter_buffer(const char *netdev_id,
>> +                                      NetFilterDirection direction,
>> +                                      Error **errp);
>>   #endif /* QEMU_NET_FILTER_H */
>> diff --git a/net/filter-buffer.c b/net/filter-buffer.c
>> index 57be149..195af68 100644
>> --- a/net/filter-buffer.c
>> +++ b/net/filter-buffer.c
>> @@ -14,6 +14,12 @@
>>   #include "qapi/qmp/qerror.h"
>>   #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"
>> +#include "qmp-commands.h"
>>
>>   #define TYPE_FILTER_BUFFER "filter-buffer"
>>
>> @@ -26,6 +32,8 @@ typedef struct FilterBufferState {
>>       NetQueue *incoming_queue;
>>       uint32_t interval;
>>       QEMUTimer release_timer;
>> +    bool is_default;
>> +    bool enable_buffer;
>>   } FilterBufferState;
>>
>>   static void filter_buffer_flush(NetFilterState *nf)
>> @@ -65,6 +73,10 @@ static ssize_t filter_buffer_receive_iov(NetFilterState *nf,
>>   {
>>       FilterBufferState *s = FILTER_BUFFER(nf);
>>
>> +    /* Don't buffer any packets if the filter is not enabled */
>> +    if (!s->enable_buffer) {
>> +        return 0;
>> +    }
>>       /*
>>        * We return size when buffer a packet, the sender will take it as
>>        * a already sent packet, so sent_cb should not be called later.
>> @@ -102,6 +114,7 @@ static void filter_buffer_cleanup(NetFilterState *nf)
>>   static void filter_buffer_setup(NetFilterState *nf, Error **errp)
>>   {
>>       FilterBufferState *s = FILTER_BUFFER(nf);
>> +    char *path = object_get_canonical_path_component(OBJECT(nf));
>>
>>       /*
>>        * We may want to accept zero interval when VM FT solutions like MC
>> @@ -114,6 +127,7 @@ static void filter_buffer_setup(NetFilterState *nf, Error **errp)
>>       }
>>
>>       s->incoming_queue = qemu_new_net_queue(qemu_netfilter_pass_to_next, nf);
>> +    s->is_default = !strcmp(path, "nop");
>>       if (s->interval) {
>>           timer_init_us(&s->release_timer, QEMU_CLOCK_VIRTUAL,
>>                         filter_buffer_release_timer, nf);
>> @@ -163,6 +177,66 @@ out:
>>       error_propagate(errp, local_err);
>>   }
>>
>> +/*
>> +* This will be used by COLO or MC FT, for which they will need
>> +* to buffer the packets of VM's net devices, Here we add a default
>> +* buffer filter for each netdev. The name of default buffer filter is
>> +* 'nop'
>> +*/
>> +void netdev_add_default_filter_buffer(const char *netdev_id,
>> +                                      NetFilterDirection direction,
>> +                                      Error **errp)
>> +{
>> +    QmpOutputVisitor *qov;
>> +    QmpInputVisitor *qiv;
>> +    Visitor *ov, *iv;
>> +    QObject *obj = NULL;
>> +    QDict *qdict;
>> +    void *dummy = NULL;
>> +    const char *id = "nop";
>> +    char *queue = g_strdup(NetFilterDirection_lookup[direction]);
>> +    NetClientState *nc = qemu_find_netdev(netdev_id);
>> +    Error *err = NULL;
>> +
>> +    /* FIXME: Not support multiple queues */
>> +    if (!nc || nc->queue_index > 1) {
>> +        return;
>> +    }
>> +    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_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(queue);
>> +    if (err) {
>> +        error_propagate(errp, err);
>> +    }
>> +}
>> +
>>   static void filter_buffer_init(Object *obj)
>>   {
>>       object_property_add(obj, "interval", "int",
>> diff --git a/net/net.c b/net/net.c
>> index ade6051..b36d49f 100644
>> --- a/net/net.c
>> +++ b/net/net.c
>> @@ -1028,6 +1028,14 @@ static int net_client_init1(const void *object, int is_netdev, Error **errp)
>>           }
>>           return -1;
>>       }
>> +
>> +    if (is_netdev) {
>> +        const Netdev *netdev = object;
>> +
>> +        netdev_add_default_filter_buffer(netdev->id,
>> +                                         NET_FILTER_DIRECTION_RX,
>> +                                         errp);
>> +    }
>>       return 0;
>>   }
>>
>>
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