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 DB08BC7EE2F for ; Tue, 6 Jun 2023 23:08:11 +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 3FD5F157EE7 for ; Tue, 6 Jun 2023 23:08:11 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 27EC398658A for ; Tue, 6 Jun 2023 23:08:11 +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 18187986583; Tue, 6 Jun 2023 23:08:11 +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 0559F986585 for ; Tue, 6 Jun 2023 23:08:11 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: gyhgyVabM-ePoTheb7ldRg-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686092888; x=1688684888; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=XmInpwKvYS6f0Kq6bT1vGscpl4MSF1GmGLF5OYOGYKA=; b=SE1Qb3tADfZPDe+Ka8H3x3/qM1M/XV3Iw25caEBjQwEX99jwZYxOn72JX21byeGiR7 cn/BuKMEtjgc45cNNlBBpwPkqcBmkV0TeXmcevSwftJY+t991azhvAHExzwtqco3xi+2 rhjesFTY7T78zoh/JlAetsz367zIW2owrZNVCxMW+B/+W3qDXiEyYgpR8kbPnlAYfuqQ fR8O4QmwFBcQv7bmlM5P7QbCuTV1kihyKKrL/x4ThBqZ7Ev4Vd5fxY7MY/VunsgXgJCi f0HSYJsf+iVzcF7YsGsj4NZF2OfRw97YYPleBfI3s1NVRVYBOVlrCctzHc2mKki9MRQt eM2g== X-Gm-Message-State: AC+VfDwtl6D1t+j7AqxHdcdRHbqbTTiV19U7gl5FuCJwxYp0HYLQ1jpD nCredr/V7svZ8hG+plj3mlWIP0P4zONRS60kZkAegxVLWKl9+dogPXGf+QvpfcgANiF6mxUNOig wMEhZNNa6jM5Pj25ZtMskiPpWMl5cCzwnew== X-Received: by 2002:a5d:458c:0:b0:309:5029:95a9 with SMTP id p12-20020a5d458c000000b00309502995a9mr2954861wrq.32.1686092887989; Tue, 06 Jun 2023 16:08:07 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ64mIg5NHjVoAkI9SQ3D26Xho5GsgKCWJVWPP8Y7Z2u+KkFVtsgGdsGdUvwVx1Jxl+r6a7Fmg== X-Received: by 2002:a5d:458c:0:b0:309:5029:95a9 with SMTP id p12-20020a5d458c000000b00309502995a9mr2954853wrq.32.1686092887662; Tue, 06 Jun 2023 16:08:07 -0700 (PDT) Date: Tue, 6 Jun 2023 19:08:04 -0400 From: "Michael S. Tsirkin" To: Parav Pandit Cc: "virtio-comment@lists.oasis-open.org" , Shahaf Shuler , "virtio@lists.oasis-open.org" Message-ID: <20230606190617-mutt-send-email-mst@kernel.org> References: <20230601220305.587034-1-parav@nvidia.com> <20230601220305.587034-7-parav@nvidia.com> <20230606183720-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Subject: Re: [virtio-comment] [PATCH requirements 6/7] net-features: Add packet timestamp requirements On Tue, Jun 06, 2023 at 10:51:25PM +0000, Parav Pandit wrote: > > > > From: Michael S. Tsirkin > > Sent: Tuesday, June 6, 2023 6:40 PM > > > > +## 3.5 Packet timestamp > > > +1. Device should provide transmit timestamp and receive timestamp of the > > packets > > > + at per packet level when the device is enabled. > > > +2. Device should provide the current free running clock in the least latency > > > + possible using an MMIO register read of 64-bit to have the least jitter. > > > > wow these reads are expensive. what is the actual requirement? > > > I don't understand the question. placing something in a register is a solution. what is the requirement? > > > +3. Device should provide the current frequency and the frequency unit for > > the > > > + software to synchronize the reference point of software and the device > > using > > > + a control vq command. > > > > let's leave mechanism out of it. I think you are trying to say this is async to data > > vqs? and cvq is fine. > > > There are two clocks running, one of cpu where driver is running, other one is in the device. > And timestamps are done by the device based on its clock. > > So driver can convert the device timestamp to driver cpu timestamp. > This is like one time query to know conversion mechanics. > > > > +### 3.5.2 Receive timestamp > > > +1. Receive completion must contain a packet reception timestamp when the > > device > > > + is enabled for it. > > > +2. The device should record the received packet timestamp at the closet > > ingress > > > + point of reception from the network. > > > +3. The device should provide a receive packet timestamp in a single DMA > > > + transaction along with the rest of the receive completion fields. > > > > how large do these need to be? ok for timer to overflow? > > > Will add it. Usually 8B. > But overflow after 30+ years or so is common norm. > > > > > > why do you mention migration in counters but not in timers? > > > > is it ok for time to go back? > > Should add it for timer too. 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/