Re: [RFC PATCH 0/5] TUN/VirtioNet USO features support.

From: Jason Wang <jasowang@redhat.com>
To: Andrew Melnichenko <andrew@daynix.com>,
	Yuri Benditovich <yuri.benditovich@daynix.com>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
	Yan Vugenfirer <yan@daynix.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	"Michael S . Tsirkin" <mst@redhat.com>,
	Network Development <netdev@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	virtualization <virtualization@lists.linux-foundation.org>
Subject: Re: [RFC PATCH 0/5] TUN/VirtioNet USO features support.
Date: Wed, 9 Feb 2022 13:41:37 +0800	[thread overview]
Message-ID: <3ab523ac-0ab5-5011-5328-e119840e1c07@redhat.com> (raw)
In-Reply-To: <CABcq3pE43rYojwUCAmpW-FKv5=ABcS47B944Y-3kDqr-PeqLwQ@mail.gmail.com>

在 2022/2/8 下午9:09, Andrew Melnichenko 写道:
> Hi people,
> Can you please review this series?

Are there any performance number to demonstrate the difference?

Thanks

>
> On Wed, Jan 26, 2022 at 10:32 AM Yuri Benditovich
> <yuri.benditovich@daynix.com> wrote:
>> On Wed, Jan 26, 2022 at 9:54 AM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote:
>>> On Tue, 25 Jan 2022 10:46:57 +0200, Andrew Melnychenko <andrew@daynix.com> wrote:
>>>> Added new offloads for TUN devices TUN_F_USO4 and TUN_F_USO6.
>>>> Technically they enable NETIF_F_GSO_UDP_L4
>>>> (and only if USO4 & USO6 are set simultaneously).
>>>> It allows to transmission of large UDP packets.
>>>>
>>>> Different features USO4 and USO6 are required for qemu where Windows guests can
>>>> enable disable USO receives for IPv4 and IPv6 separately.
>>>> On the other side, Linux can't really differentiate USO4 and USO6, for now.
>>>> For now, to enable USO for TUN it requires enabling USO4 and USO6 together.
>>>> In the future, there would be a mechanism to control UDP_L4 GSO separately.
>>>>
>>>> Test it WIP Qemu https://github.com/daynix/qemu/tree/Dev_USOv2
>>>>
>>>> New types for VirtioNet already on mailing:
>>>> https://lists.oasis-open.org/archives/virtio-comment/202110/msg00010.html
>>> Seems like this hasn't been upvoted yet.
>>>
>>>          https://github.com/oasis-tcs/virtio-spec#use-of-github-issues
>> Yes, correct. This is a reason why this series of patches is RFC.
>>
>>> Thanks.
>>>
>>>> Also, there is a known issue with transmitting packages between two guests.
>>>> Without hacks with skb's GSO - packages are still segmented on the host's postrouting.
>>>>
>>>> Andrew Melnychenko (5):
>>>>    uapi/linux/if_tun.h: Added new ioctl for tun/tap.
>>>>    driver/net/tun: Added features for USO.
>>>>    uapi/linux/virtio_net.h: Added USO types.
>>>>    linux/virtio_net.h: Added Support for GSO_UDP_L4 offload.
>>>>    drivers/net/virtio_net.c: Added USO support.
>>>>
>>>>   drivers/net/tap.c               | 18 ++++++++++++++++--
>>>>   drivers/net/tun.c               | 15 ++++++++++++++-
>>>>   drivers/net/virtio_net.c        | 22 ++++++++++++++++++----
>>>>   include/linux/virtio_net.h      | 11 +++++++++++
>>>>   include/uapi/linux/if_tun.h     |  3 +++
>>>>   include/uapi/linux/virtio_net.h |  4 ++++
>>>>   6 files changed, 66 insertions(+), 7 deletions(-)
>>>>
>>>> --
>>>> 2.34.1
>>>>
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