From: "Michael S. Tsirkin" <mst@redhat.com>
To: Heng Qi <hengqi@linux.alibaba.com>
Cc: Jason Wang <jasowang@redhat.com>,
virtio-dev@lists.oasis-open.org,
Cornelia Huck <cohuck@redhat.com>,
xuanzhuo@linux.alibaba.com, kangjie.xu@linux.alibaba.com
Subject: Re: [PATCH v7] virtio_net: support split header
Date: Sun, 4 Sep 2022 16:27:38 -0400 [thread overview]
Message-ID: <20220904162337-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <d091f3e4-3d69-f0ba-5c6b-d3e05ca6b88c@linux.alibaba.com>
On Fri, Sep 02, 2022 at 03:36:25PM +0800, Heng Qi wrote:
> We need to clarify that the purpose of header splitting is to make all payloads
> can be independently in a page, which is beneficial for the zerocopy
> implemented by the upper layer.
absolutely, pls add motivation.
> If the driver does not enforce that the buffers submitted to the receiveq MUST
> be composed of at least two descriptors, then header splitting will become meaningless,
> or the VIRTIO_NET_F_SPLIT_TRANSPORT_HEADER feature should not be negotiated at this time.
>
>
> Thanks.
>
>
This seems very narrow and unecessarily wasteful of descriptors.
What is wrong in this:
<header>...<padding>... <beginning of page><data>
seems to achieve the goal of data in a separate page without
using extra descriptors.
thus my proposal to replace the requirement of a separate
descriptor with an offset of data from beginning of
buffer that driver sets.
--
MST
next prev parent reply other threads:[~2022-09-04 20:27 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-16 9:34 [virtio-dev] [PATCH v7] virtio_net: support split header Heng Qi
2022-08-25 14:22 ` Cornelia Huck
2022-08-30 11:23 ` Heng Qi
2022-08-30 11:26 ` Heng Qi
2022-09-02 4:12 ` Heng Qi
2022-09-08 21:18 ` Michael S. Tsirkin
2022-09-02 6:21 ` [virtio-dev] " Jason Wang
2022-09-02 6:41 ` Michael S. Tsirkin
2022-09-02 8:58 ` Heng Qi
2022-09-04 20:31 ` Michael S. Tsirkin
2022-09-05 7:52 ` Xuan Zhuo
2022-09-05 8:37 ` Heng Qi
2022-09-05 9:43 ` Xuan Zhuo
2022-09-06 5:47 ` Jason Wang
2022-09-08 21:18 ` Michael S. Tsirkin
2022-09-02 7:36 ` Heng Qi
2022-09-04 20:27 ` Michael S. Tsirkin [this message]
2022-09-06 5:56 ` Jason Wang
2022-09-09 7:41 ` [virtio-dev] " Heng Qi
2022-09-09 11:15 ` Michael S. Tsirkin
2022-09-09 12:38 ` Xuan Zhuo
2022-09-14 3:34 ` Jason Wang
2022-09-27 21:35 ` Michael S. Tsirkin
2022-09-28 2:15 ` Heng Qi
2022-09-28 8:01 ` Xuan Zhuo
2022-09-09 12:47 ` Xuan Zhuo
2022-09-13 7:20 ` Heng Qi
2022-09-09 10:22 ` Heng Qi
2022-09-02 8:26 ` Heng Qi
2022-09-06 5:53 ` Jason Wang
2022-09-02 6:48 ` Michael S. Tsirkin
2022-09-07 11:16 ` [virtio-dev] " Heng Qi
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