From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from ws5-mx01.kavi.com (ws5-mx01.kavi.com [34.193.7.191]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AC24FC10DC1 for ; Fri, 1 Dec 2023 07:15:55 +0000 (UTC) Received: from lists.oasis-open.org (oasis.ws5.connectedcommunity.org [10.110.1.242]) by ws5-mx01.kavi.com (Postfix) with ESMTP id 0CBFC2B021 for ; Fri, 1 Dec 2023 07:15:55 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id E606D9866A4 for ; Fri, 1 Dec 2023 07:15:54 +0000 (UTC) Received: from host09.ws5.connectedcommunity.org (host09.ws5.connectedcommunity.org [10.110.1.97]) by lists.oasis-open.org (Postfix) with QMQP id CC01998614B; Fri, 1 Dec 2023 07:15:54 +0000 (UTC) Mailing-List: contact virtio-comment-help@lists.oasis-open.org; run by ezmlm List-ID: Sender: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id BC6BE98669A for ; Fri, 1 Dec 2023 07:15:54 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R981e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045176;MF=hengqi@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0VxXwOer_1701414949; Message-ID: Date: Fri, 1 Dec 2023 15:15:45 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Jason Wang Cc: virtio-comment@lists.oasis-open.org, "Michael S . Tsirkin" , Xuan Zhuo References: <5490c3b5b2321e13a9344057d02f2ae5fe9ebf56.1701158152.git.hengqi@linux.alibaba.com> <90ef9ec4-6cce-49c4-a27d-7168990ae3f3@linux.alibaba.com> <5bb13b60-f324-412f-99a2-a476320d79b1@linux.alibaba.com> <00b1ed5f-fc91-4aba-b650-2830cd5ac412@linux.alibaba.com> From: Heng Qi In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [virtio-comment] Re: [PATCH v4 1/2] virtio-net: update description for VIRTIO_NET_F_GUEST_CSUM. 在 2023/12/1 下午3:05, Jason Wang 写道: > On Fri, Dec 1, 2023 at 2:30 PM Heng Qi wrote: >> >> >> 在 2023/12/1 下午2:24, Heng Qi 写道: >>> >>> 在 2023/12/1 下午1:18, Jason Wang 写道: >>>> On Wed, Nov 29, 2023 at 4:23 PM Heng Qi >>>> wrote: >>>>> >>>>> 在 2023/11/29 下午4:00, Jason Wang 写道: >>>>>> On Tue, Nov 28, 2023 at 4:08 PM Heng Qi >>>>>> wrote: >>>>>>> To prevent readers from misunderstanding that the driver can >>>>>>> only handles packets with partial checksum when >>>>>>> VIRTIO_NET_F_GUEST_CSUM is negotiated, we update the description. >>>>>>> >>>>>>> Signed-off-by: Heng Qi >>>>>>> --- >>>>>>> device-types/net/description.tex | 2 +- >>>>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>>>> >>>>>>> diff --git a/device-types/net/description.tex >>>>>>> b/device-types/net/description.tex >>>>>>> index aff5e08..529f470 100644 >>>>>>> --- a/device-types/net/description.tex >>>>>>> +++ b/device-types/net/description.tex >>>>>>> @@ -38,7 +38,7 @@ \subsection{Feature bits}\label{sec:Device Types >>>>>>> / Network Device / Feature bits >>>>>>> \begin{description} >>>>>>> \item[VIRTIO_NET_F_CSUM (0)] Device handles packets with >>>>>>> partial checksum offload. >>>>>>> >>>>>>> -\item[VIRTIO_NET_F_GUEST_CSUM (1)] Driver handles packets with >>>>>>> partial checksum. >>>>>>> +\item[VIRTIO_NET_F_GUEST_CSUM (1)] Driver handles packets with >>>>>>> partial checksum or full checksum. >>>>>> So patch 2 said >>>>>> >>>>>> " >>>>>> +\item[VIRTIO_NET_F_GUEST_FULL_CSUM (64)] Driver handles packets with >>>>>> full checksum. >>>>>> \end{description} >>>>>> " >>>>>> >>>>>> Is there any difference between the two "full checksum" here? >>>>> There's no difference. >>>>> >>>>> The core is that VIRTIO_NET_F_GUEST_FULL_CSUM means that the driver >>>>> "can >>>>> only" handle packets with full checksum. >>>> This seems to be odd. >>>> >>>> Driver can always handle packet with full checksum, no? >>> Yes. >>> >>>> I meant it >>>> will be then to be functional equivalent to ! >>>> VIRTIO_NET_F_GUEST_FULL_CSUM? >>> Are you referring to >>> "functional equivalent to !VIRTIO_NET_F_GUEST_CSUM" ? >> Sorry, this is a typo. I meant >> >> Are you referring to >> "functional equivalent to !VIRTIO_NET_F_GUEST_FULL_CSUM" ? >> >>> If so, I think it's no. >>> >>> Maybe a description similar to the following would be more clearer: >>> >>> +\item[VIRTIO_NET_F_GUEST_FULL_CSUM (64)] Driver does not handle >>> packets with partial checksum. > I may miss something here, but what's the difference between > > VIRTIO_NET_F_GUEST_FULL_CSUM > > and > > !VIRTIO_NET_F_GUEST_CSUM? From the device perspective: If !VIRTIO_NET_F_GUEST_CSUM, the device delivers packets with full checksum to the driver, but the device can not validate the checksum for these packets. That is, the flags in virtio-net-hdr will not contain _DATA_VALID, and the driver or stack needs to validate these packets. If VIRTIO_NET_F_GUEST_FULL_CSUM, the device delivers packets with full checksum to the driver, and the device can validate the checksum for these packets. That is, the flags in virtio-net-hdr will contain _DATA_VALID, and the driver or stack does not need to validate these packets. Thanks! > > Thanks > >>> Thanks! >>> >>>> Thanks >>>> >>>>> Thanks! >>>>> >>>>>> Thanks >>>>>> >>>>>>> \item[VIRTIO_NET_F_CTRL_GUEST_OFFLOADS (2)] Control channel offloads >>>>>>> reconfiguration support. >>>>>>> -- >>>>>>> 2.19.1.6.gb485710b >>>>>>> >>> >>> This publicly archived list offers a means to provide input to the >>> OASIS Virtual I/O Device (VIRTIO) TC. >>> >>> In order to verify user consent to the Feedback License terms and >>> to minimize spam in the list archive, subscription is required >>> before posting. >>> >>> Subscribe: virtio-comment-subscribe@lists.oasis-open.org >>> Unsubscribe: virtio-comment-unsubscribe@lists.oasis-open.org >>> List help: virtio-comment-help@lists.oasis-open.org >>> List archive: https://lists.oasis-open.org/archives/virtio-comment/ >>> Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf >>> List Guidelines: >>> https://www.oasis-open.org/policies-guidelines/mailing-lists >>> Committee: https://www.oasis-open.org/committees/virtio/ >>> Join OASIS: https://www.oasis-open.org/join/ This publicly archived list offers a means to provide input to the OASIS Virtual I/O Device (VIRTIO) TC. In order to verify user consent to the Feedback License terms and to minimize spam in the list archive, subscription is required before posting. Subscribe: virtio-comment-subscribe@lists.oasis-open.org Unsubscribe: virtio-comment-unsubscribe@lists.oasis-open.org List help: virtio-comment-help@lists.oasis-open.org List archive: https://lists.oasis-open.org/archives/virtio-comment/ Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf List Guidelines: https://www.oasis-open.org/policies-guidelines/mailing-lists Committee: https://www.oasis-open.org/committees/virtio/ Join OASIS: https://www.oasis-open.org/join/