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 14:25, Wen Congyang wrote:
> On 12/03/2015 11:53 AM, Hailiang Zhang wrote:
>> 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.
>
> Yes, I have tested it. When I want to start a normal vm with vhost, I get
> the following error messages:
>
> qemu-system-x86_64: -netdev tap,id=hn0,queues=1,vhost=on: Vhost is not supported
>

Hmm, that is reported by filter in nextfilter_complete(), i will investigate it.
We hope the default buffer filter has no side effect on netdev.

Thanks,
Hailiang

>>
>>> 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;
>>>>    }
>>>>
>>>>
>>>
>>>
>>>
>>>
>>> .
>>>
>>
>>
>>
>>
>> .
>>
>
>
>
>
> .
>