From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 27 Feb 2023 02:29:54 -0500 From: "Michael S. Tsirkin" Subject: Re: [PATCH v1 2/2] transport-pci: Move transitional device id to legacy section Message-ID: <20230227022459-mutt-send-email-mst@kernel.org> References: <20230225220636.429990-1-parav@nvidia.com> <20230225220636.429990-3-parav@nvidia.com> <20230225175847-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=us-ascii Content-Disposition: inline To: Parav Pandit Cc: "virtio-dev@lists.oasis-open.org" , "cohuck@redhat.com" , "virtio-comment@lists.oasis-open.org" , Shahaf Shuler List-ID: On Mon, Feb 27, 2023 at 02:54:09AM +0000, Parav Pandit wrote: > > > > From: Michael S. Tsirkin > > Sent: Saturday, February 25, 2023 6:00 PM > > > > On Sun, Feb 26, 2023 at 12:06:36AM +0200, Parav Pandit wrote: > > > Currently PCI device requirements section contains mix of normative > > > statements for for regular (non transitional) device and transitional > > > device under one section. > > > > > > Some requirements of the transitional device are also located in > > > legacy interface section which is the right section for it. > > > > > > Hence, > > > 1. Move transitional device requirements to their designated Legacy > > > interface section > > > 2. Describe regular device requirements without quoting it as "non > > > transitional device" > > > > > > While at it, write the description using a singular object definition. > > > > > > This is only an editorial change. > > > > > > This patch is on top of [1]. > > > > > > [1] > > > https://lists.oasis-open.org/archives/virtio-dev/202302/msg00578.html > > > > > > Signed-off-by: Parav Pandit > > > > nack I already answered this. legacy sections describe legacy interface of > > transitional devices. > > > Legacy device id of the transitional device is 0x1000 for net. > Legacy revision id of the transitional device is 0x0. > Why revision id belongs to legacy section, but device id doesn't? > Still trying to understand this convoluted policy. > Will re-read your email again if that is explained somehow without bringing the driver in context. It's convoluted because legacy is convoluted. It's a bolt-on. We have a modern description. Is says e.g. "A". Then legacy chapter comes and say "yea but legacy is B". This is not how spec normally works. The rule is this: one should be able to ignore legacy sections if not building a legacy driver/device. If you are building a modern driver it must support transitional devices. Thus is must know about id 0x1000. Conclusion - 0x1000 is out of legacy section. If you are building a modern driver it ignores revision. But legacy drivers used revision 0. So a transitional device has 0 to make legacy drivers work. Conclusion - revision 0 is in the legacy section. -- MST 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 DE74BC64ED6 for ; Mon, 27 Feb 2023 07:30:05 +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 2550F42569 for ; Mon, 27 Feb 2023 07:30:04 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id AC9D5986478 for ; Mon, 27 Feb 2023 07:30:03 +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 935719863ED; Mon, 27 Feb 2023 07:30:03 +0000 (UTC) Mailing-List: contact virtio-dev-help@lists.oasis-open.org; run by ezmlm List-Id: 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 6F7289867A1 for ; Mon, 27 Feb 2023 07:30:03 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: 7q3DE8opP8OxL_bgpmOlHQ-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; 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=rNUfwFaFOY8QX6jGal77DS3EdlL8Gkt7tXai/vH/f/o=; b=zvz66QAywiycAIxsmQX3BnUI88TR8G07+XGcbC+9rLytIXQAeenN/LzfquOTYLBhcu ObmHdbGSBl5SKAOo/5r1szGeF9vZ/zaHe9AfIT9f4uBPTvHePjLboQMBcaWaH8H85XyV jhF3MMHMsDWacrlUY5hLlBgQrMeTJS6PnbKqkBNXVYH4prflpFW/gTsCsuZTQTr21/Sg e/JHXRXbttkEV+XMDifhutj937ke18kWoeDMFRGRBc1dH8VwTiAz6WAAeOpYGlZZydFn uJx7zdWzUz457WgFbHJvGLwiwJSkl1SB89j5kA9/HzFfE+XUwSkbGR739BFQ2AHrPmGG VyGA== X-Gm-Message-State: AO0yUKVg2+VMFz9aZlyOLxCJLBcS+FDcgvIJ2GA4bNYSQEwtwhBGf9Lr Yb3pzdOFKhZpaa9sbBtNkSiY4O+PsI8ssLVySLDQ56KSG911/p7AninoBObPDCwBrZNZoS/V11c BVEsLp6Rj1KJypSWPkrr9qkjnSzvu X-Received: by 2002:a17:906:5acb:b0:886:7eae:26c4 with SMTP id x11-20020a1709065acb00b008867eae26c4mr31162485ejs.5.1677482999185; Sun, 26 Feb 2023 23:29:59 -0800 (PST) X-Google-Smtp-Source: AK7set9dcknCyOVszSciiDXf2VKqORKvwGpe8u1jyIUWDGdO947rjyyPtC9D4QpAfj/y8qUuOVOPEA== X-Received: by 2002:a17:906:5acb:b0:886:7eae:26c4 with SMTP id x11-20020a1709065acb00b008867eae26c4mr31162472ejs.5.1677482998906; Sun, 26 Feb 2023 23:29:58 -0800 (PST) Date: Mon, 27 Feb 2023 02:29:54 -0500 From: "Michael S. Tsirkin" To: Parav Pandit Cc: "virtio-dev@lists.oasis-open.org" , "cohuck@redhat.com" , "virtio-comment@lists.oasis-open.org" , Shahaf Shuler Message-ID: <20230227022459-mutt-send-email-mst@kernel.org> References: <20230225220636.429990-1-parav@nvidia.com> <20230225220636.429990-3-parav@nvidia.com> <20230225175847-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: [virtio-dev] Re: [PATCH v1 2/2] transport-pci: Move transitional device id to legacy section Message-ID: <20230227072954.yKLVlmPrIBQdg6xO_3duWCAziaPcyOU4UY1uoiytsaY@z> On Mon, Feb 27, 2023 at 02:54:09AM +0000, Parav Pandit wrote: > > > > From: Michael S. Tsirkin > > Sent: Saturday, February 25, 2023 6:00 PM > > > > On Sun, Feb 26, 2023 at 12:06:36AM +0200, Parav Pandit wrote: > > > Currently PCI device requirements section contains mix of normative > > > statements for for regular (non transitional) device and transitional > > > device under one section. > > > > > > Some requirements of the transitional device are also located in > > > legacy interface section which is the right section for it. > > > > > > Hence, > > > 1. Move transitional device requirements to their designated Legacy > > > interface section > > > 2. Describe regular device requirements without quoting it as "non > > > transitional device" > > > > > > While at it, write the description using a singular object definition. > > > > > > This is only an editorial change. > > > > > > This patch is on top of [1]. > > > > > > [1] > > > https://lists.oasis-open.org/archives/virtio-dev/202302/msg00578.html > > > > > > Signed-off-by: Parav Pandit > > > > nack I already answered this. legacy sections describe legacy interface of > > transitional devices. > > > Legacy device id of the transitional device is 0x1000 for net. > Legacy revision id of the transitional device is 0x0. > Why revision id belongs to legacy section, but device id doesn't? > Still trying to understand this convoluted policy. > Will re-read your email again if that is explained somehow without bringing the driver in context. It's convoluted because legacy is convoluted. It's a bolt-on. We have a modern description. Is says e.g. "A". Then legacy chapter comes and say "yea but legacy is B". This is not how spec normally works. The rule is this: one should be able to ignore legacy sections if not building a legacy driver/device. If you are building a modern driver it must support transitional devices. Thus is must know about id 0x1000. Conclusion - 0x1000 is out of legacy section. If you are building a modern driver it ignores revision. But legacy drivers used revision 0. So a transitional device has 0 to make legacy drivers work. Conclusion - revision 0 is in the legacy section. -- MST --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org