From: "Xie, Huawei" <huawei.xie@intel.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Yuanhan Liu <yuanhan.liu@linux.intel.com>,
"Loftus, Ciara" <ciara.loftus@intel.com>,
"dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH 3/6] vhost: add reconnect ability
Date: Tue, 10 May 2016 09:00:45 +0000 [thread overview]
Message-ID: <C37D651A908B024F974696C65296B57B4C7573CC@SHSMSX101.ccr.corp.intel.com> (raw)
In-Reply-To: <20160510114044-mutt-send-email-mst@redhat.com>
On 5/10/2016 4:42 PM, Michael S. Tsirkin wrote:
> On Tue, May 10, 2016 at 08:07:00AM +0000, Xie, Huawei wrote:
>> On 5/10/2016 3:56 PM, Michael S. Tsirkin wrote:
>>> On Tue, May 10, 2016 at 07:24:10AM +0000, Xie, Huawei wrote:
>>>> On 5/10/2016 2:08 AM, Yuanhan Liu wrote:
>>>>> On Mon, May 09, 2016 at 04:47:02PM +0000, Xie, Huawei wrote:
>>>>>> On 5/7/2016 2:36 PM, Yuanhan Liu wrote:
>>>>>>> +static void *
>>>>>>> +vhost_user_client_reconnect(void *arg)
>>>>>>> +{
>>>>>>> + struct reconnect_info *reconn = arg;
>>>>>>> + int ret;
>>>>>>> +
>>>>>>> + RTE_LOG(ERR, VHOST_CONFIG, "reconnecting...\n");
>>>>>>> + while (1) {
>>>>>>> + ret = connect(reconn->fd, (struct sockaddr *)&reconn->un,
>>>>>>> + sizeof(reconn->un));
>>>>>>> + if (ret == 0)
>>>>>>> + break;
>>>>>>> + sleep(1);
>>>>>>> + }
>>>>>>> +
>>>>>>> + vhost_user_add_connection(reconn->fd, reconn->vsocket);
>>>>>>> + free(reconn);
>>>>>>> +
>>>>>>> + return NULL;
>>>>>>> +}
>>>>>>> +
>>>>>> We could create hundreds of vhost-user ports in OVS. Wihout connections
>>>>>> with QEMU established, those ports are just inactive. This works fine in
>>>>>> server mode.
>>>>>> With client modes, do we need to create hundreds of vhost threads? This
>>>>>> would be too interruptible.
>>>>>> How about we create only one thread and do the reconnections for all the
>>>>>> unconnected socket?
>>>>> Yes, good point and good suggestion. Will do it in v2.
>>>> Hi Michael:
>>>> This reminds me another irrelevant issue.
>>>> In OVS, currently for each vhost port, we create an unix domain socket,
>>>> and QEMU vhost proxy connects to this socket, and we use this to
>>>> identify the connection. This works fine but is our workaround,
>>>> otherwise we have no way to identify the connection.
>>>> Do you think if this is an issue?
>> Let us say vhost creates one unix domain socket, with path as "sockpath",
>> and two virtio ports in two VMS both connect to the same socket with the
>> following command line
>> -chardev socket,id=char0,path=sockpath
>> How could vhost identify the connection?
> getpeername(2)?
getpeer name returns host/port? then it isn't useful.
The typical scenario in my mind is:
We create a OVS port with the name "port1", and when we receive an
virtio connection with ID "port1", we attach this virtio interface to
the OVS port "port1".
>
>
>> Workarounds:
>> vhost creates two unix domain sockets, with path as "sockpath1" and
>> "sockpath2" respectively,
>> and the virtio ports in two VMS respectively connect to "sockpath1" and
>> "sockpath2".
>>
>> If we have some name string from QEMU over vhost, as you mentioned, we
>> could create only one socket with path "sockpath".
>> User ensure that the names are unique, just as how they do with multiple
>> sockets.
>>
> Seems rather fragile.
>From the scenario above, it is enough. That is also how it works today
in DPDK OVS implementation with multiple sockets.
Any other idea?
>
>>> I'm sorry, I have trouble understanding what you wrote above.
>>> What is the issue you are trying to work around?
>>>
>>>> Do we have plan to support identification in VHOST_USER_MESSAGE? With
>>>> the identification, if vhost as server, we only need to create one
>>>> socket which receives multiple connections, and use the ID in the
>>>> message to identify the connection.
>>>>
>>>> /huawei
>>> Sending e.g. -name string from qemu over vhost might be useful
>>> for debugging, but I'm not sure it's a good idea to
>>> rely on it being unique.
>>>
>>>>> Thanks.
>>>>>
>>>>> --yliu
>>>>>
next prev parent reply other threads:[~2016-05-10 9:00 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-07 6:40 [dpdk-dev] [PATCH 0/6] vhost: add vhost-user client mode and " Yuanhan Liu
2016-05-07 6:40 ` [dpdk-dev] [PATCH 1/6] vhost: rename structs for enabling client mode Yuanhan Liu
2016-05-07 6:40 ` [dpdk-dev] [PATCH 2/6] vhost: add vhost-user " Yuanhan Liu
2016-05-09 10:33 ` Victor Kaplansky
2016-05-09 20:33 ` Yuanhan Liu
2016-05-09 20:30 ` Michael S. Tsirkin
2016-05-07 6:40 ` [dpdk-dev] [PATCH 3/6] vhost: add reconnect ability Yuanhan Liu
2016-05-09 16:47 ` Xie, Huawei
2016-05-09 18:12 ` Yuanhan Liu
2016-05-10 7:24 ` Xie, Huawei
2016-05-10 7:54 ` Michael S. Tsirkin
2016-05-10 8:07 ` Xie, Huawei
2016-05-10 8:42 ` Michael S. Tsirkin
2016-05-10 9:00 ` Xie, Huawei [this message]
2016-05-10 9:17 ` Michael S. Tsirkin
2016-05-10 17:17 ` Loftus, Ciara
2016-05-11 21:46 ` Michael S. Tsirkin
2016-05-07 6:40 ` [dpdk-dev] [PATCH 4/6] vhost: workaround stale vring base Yuanhan Liu
2016-05-09 10:45 ` Victor Kaplansky
2016-05-09 13:39 ` Xie, Huawei
2016-05-09 18:23 ` Yuanhan Liu
2016-05-09 12:19 ` Michael S. Tsirkin
2016-05-09 16:25 ` Xie, Huawei
2016-05-09 18:22 ` Yuanhan Liu
2016-06-13 20:47 ` Michael S. Tsirkin
2016-05-10 8:21 ` Xie, Huawei
2016-05-07 6:40 ` [dpdk-dev] [PATCH 5/6] examples/vhost: add client and reconnect option Yuanhan Liu
2016-05-09 10:47 ` Victor Kaplansky
2016-05-07 6:40 ` [dpdk-dev] [PATCH 6/6] vhost: add pmd " Yuanhan Liu
2016-05-09 10:54 ` Victor Kaplansky
2016-05-09 18:26 ` Yuanhan Liu
2016-05-10 3:23 ` [dpdk-dev] [PATCH 0/6] vhost: add vhost-user client mode and reconnect ability Xu, Qian Q
2016-05-10 17:41 ` Yuanhan Liu
2016-05-13 6:16 ` [dpdk-dev] [PATCH v2 " Yuanhan Liu
2016-05-13 6:16 ` [dpdk-dev] [PATCH v2 1/6] vhost: rename structs for enabling client mode Yuanhan Liu
2016-05-13 6:16 ` [dpdk-dev] [PATCH v2 2/6] vhost: add vhost-user " Yuanhan Liu
2016-05-13 6:16 ` [dpdk-dev] [PATCH v2 3/6] vhost: add reconnect ability Yuanhan Liu
2016-05-13 6:16 ` [dpdk-dev] [PATCH v2 4/6] vhost: workaround stale vring base Yuanhan Liu
2016-05-13 6:16 ` [dpdk-dev] [PATCH v2 5/6] examples/vhost: add client and reconnect option Yuanhan Liu
2016-05-13 6:16 ` [dpdk-dev] [PATCH v2 6/6] vhost: add pmd " Yuanhan Liu
2016-05-25 17:45 ` Rich Lane
2016-05-26 8:01 ` Yuanhan Liu
2016-06-07 4:05 ` [dpdk-dev] [PATCH v3 0/6] vhost: add vhost-user client mode and reconnect ability Yuanhan Liu
2016-06-07 4:05 ` [dpdk-dev] [PATCH v3 1/6] vhost: rename structs for enabling client mode Yuanhan Liu
2016-06-07 4:05 ` [dpdk-dev] [PATCH v3 2/6] vhost: add vhost-user " Yuanhan Liu
2016-06-07 4:05 ` [dpdk-dev] [PATCH v3 3/6] vhost: add reconnect ability Yuanhan Liu
2016-06-07 4:05 ` [dpdk-dev] [PATCH v3 4/6] vhost: workaround stale vring base Yuanhan Liu
2016-06-07 4:05 ` [dpdk-dev] [PATCH v3 5/6] examples/vhost: add client option Yuanhan Liu
2016-06-07 4:05 ` [dpdk-dev] [PATCH v3 6/6] vhost: add pmd " Yuanhan Liu
2016-06-14 12:00 ` [dpdk-dev] [PATCH v3 0/6] vhost: add vhost-user client mode and reconnect ability Yuanhan Liu
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