From: "Tan, Jianfeng" <jianfeng.tan@intel.com>
To: Maxime Coquelin <maxime.coquelin@redhat.com>,
aconole@redhat.com, sodey@sonusnet.com,
yuanhan.liu@linux.intel.com, thomas.monjalon@6wind.com,
dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v3 7/9] net/virtio: Add MTU feature support
Date: Wed, 5 Apr 2017 17:42:39 +0800 [thread overview]
Message-ID: <a832d123-c086-f0a5-7d1f-649f825c1041@intel.com> (raw)
In-Reply-To: <12327337-70fd-168a-d836-026d619089f8@redhat.com>
Hi Maxime,
Thank you for replying.
On 4/5/2017 3:11 PM, Maxime Coquelin wrote:
> Hi Jianfeng,
>
> On 04/05/2017 06:52 AM, Tan, Jianfeng wrote:
>> Hi Maxime,
>>
>> Have some confusion about this feature. Please help confirm.
>>
>> (1) With this feature, we only support to advertise MTU value which is
>> defined by QEMU to frontend and backend driver separately. (2) But it
>> does not allow frontend driver to set a different MTU to QEMU and then
>> to vhost backend.
>>
>> Correct?
>> If it's correct, why not MTU works like (2)?
>
> Because idea is that the hosts advertises the maximum MTU value it
> supports. The frontend driver is free to use a smaller value. The goal
> of this change is to make possible to set a uniform MTU value across
> the infrastructure, the management tools giving a hint to the guests on
> the MTU value it should use.
Based on that MTU is the maximum packet size that can be sent instead of
that can be received:
(1) Why vhost (as a device) does not drop any packets which are longer
than MTU when dequeue()?
(2) See some NICs also use MTU to calculate maximum packet size that can
be received, like ixgbe, i40e, shall we also do that?
>
> Having the frontend setting the backend MTU dynamically would require
> some negotiation at runtime, and is out of the scope of this change.
> Do you have some use cases for this?
No, just to understand more about this feature. Thank you!
Thanks,
Jianfeng
>
> Regards,
> Maxime
>> Thanks,
>> Jianfeng
next prev parent reply other threads:[~2017-04-05 9:42 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-13 14:28 [dpdk-dev] [PATCH 0/7] virtio/vhost: " Maxime Coquelin
2017-02-13 14:28 ` [dpdk-dev] [PATCH 1/7] vhost: Enable VIRTIO_NET_F_MTU feature Maxime Coquelin
2017-02-13 14:28 ` [dpdk-dev] [PATCH 2/7] vhost: vhost-user: Add MTU protocol feature support Maxime Coquelin
2017-02-13 14:28 ` [dpdk-dev] [PATCH 3/7] vhost: Add new ready status flag Maxime Coquelin
2017-02-13 14:28 ` [dpdk-dev] [PATCH 4/7] vhost: Add API to get/set MTU value Maxime Coquelin
2017-02-13 14:28 ` [dpdk-dev] [PATCH 5/7] net/vhost: Implement mtu_set callback Maxime Coquelin
2017-02-13 14:28 ` [dpdk-dev] [PATCH 6/7] net/virtio: Add MTU feature support Maxime Coquelin
2017-02-16 19:31 ` Aaron Conole
2017-02-16 21:17 ` Maxime Coquelin
2017-02-13 14:28 ` [dpdk-dev] [PATCH 7/7] app/testpmd: print MTU value in show port info Maxime Coquelin
2017-02-23 7:10 ` [dpdk-dev] [PATCH 0/7] virtio/vhost: Add MTU feature support Yuanhan Liu
2017-03-01 7:44 ` Maxime Coquelin
2017-03-06 8:27 ` [dpdk-dev] [PATCH v2 " Maxime Coquelin
2017-03-06 8:27 ` [dpdk-dev] [PATCH v2 1/7] vhost: Enable VIRTIO_NET_F_MTU feature Maxime Coquelin
2017-03-06 8:27 ` [dpdk-dev] [PATCH v2 2/7] vhost: vhost-user: Add MTU protocol feature support Maxime Coquelin
2017-03-08 2:31 ` Yuanhan Liu
2017-03-12 10:24 ` Maxime Coquelin
2017-03-06 8:27 ` [dpdk-dev] [PATCH v2 3/7] vhost: Add new ready status flag Maxime Coquelin
2017-03-06 8:27 ` [dpdk-dev] [PATCH v2 4/7] vhost: Add API to get MTU value Maxime Coquelin
2017-03-08 2:45 ` Yuanhan Liu
2017-03-12 10:23 ` Maxime Coquelin
2017-03-06 8:27 ` [dpdk-dev] [PATCH v2 5/7] net/vhost: Fill rte_eth_dev's MTU property Maxime Coquelin
2017-03-06 8:27 ` [dpdk-dev] [PATCH v2 6/7] net/virtio: Add MTU feature support Maxime Coquelin
2017-03-06 8:27 ` [dpdk-dev] [PATCH v2 7/7] app/testpmd: print MTU value in show port info Maxime Coquelin
2017-03-07 21:57 ` [dpdk-dev] [PATCH v2 0/7] virtio/vhost: Add MTU feature support Thomas Monjalon
2017-03-12 10:00 ` Maxime Coquelin
2017-03-12 16:33 ` [dpdk-dev] [PATCH v3 0/9] " Maxime Coquelin
2017-03-12 16:33 ` [dpdk-dev] [PATCH v3 1/9] vhost: Enable VIRTIO_NET_F_MTU feature Maxime Coquelin
2017-03-12 16:33 ` [dpdk-dev] [PATCH v3 2/9] vhost: vhost-user: Add MTU protocol feature support Maxime Coquelin
2017-03-12 16:34 ` [dpdk-dev] [PATCH v3 3/9] vhost: Add new ready status flag Maxime Coquelin
2017-03-12 16:34 ` [dpdk-dev] [PATCH v3 4/9] vhost: Add API to get MTU value Maxime Coquelin
2017-03-16 8:00 ` Yuanhan Liu
2017-03-16 11:37 ` Maxime Coquelin
2017-03-17 5:32 ` Yuanhan Liu
2017-03-17 9:59 ` Maxime Coquelin
2017-03-20 8:42 ` Yuanhan Liu
2017-03-12 16:34 ` [dpdk-dev] [PATCH v3 5/9] vhost: export " Maxime Coquelin
2017-03-12 16:34 ` [dpdk-dev] [PATCH v3 6/9] net/vhost: Fill rte_eth_dev's MTU property Maxime Coquelin
2017-03-12 16:34 ` [dpdk-dev] [PATCH v3 7/9] net/virtio: Add MTU feature support Maxime Coquelin
2017-04-05 4:52 ` Tan, Jianfeng
2017-04-05 7:11 ` Maxime Coquelin
2017-04-05 9:42 ` Tan, Jianfeng [this message]
2017-04-05 13:54 ` Maxime Coquelin
2017-04-05 14:50 ` Tan, Jianfeng
2017-04-07 16:40 ` Maxime Coquelin
2017-04-10 6:48 ` Tan, Jianfeng
2017-03-12 16:34 ` [dpdk-dev] [PATCH v3 8/9] doc: announce Virtio and Vhost MTU support Maxime Coquelin
2017-03-12 16:34 ` [dpdk-dev] [PATCH v3 9/9] app/testpmd: print MTU value in show port info Maxime Coquelin
2017-03-22 8:58 ` [dpdk-dev] [PATCH v3 0/9] virtio/vhost: Add MTU feature support Yuanhan Liu
2017-03-22 9:03 ` Maxime Coquelin
2017-03-28 5:39 ` Yao, Lei A
2017-03-30 11:34 ` Maxime Coquelin
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