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 42561C25B6B for ; Thu, 26 Oct 2023 06:24:48 +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 98A0D2A828 for ; Thu, 26 Oct 2023 06:24:47 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 8183C986A4F for ; Thu, 26 Oct 2023 06:24:47 +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 74907986A46; Thu, 26 Oct 2023 06:24:47 +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 65FAF986A47 for ; Thu, 26 Oct 2023 06:24:47 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: -hU7Ohf4MxOkWsULBD_YAg-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698301451; x=1698906251; 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=NLdsBO7JBK/0anQJHAtgoGvEQhyQwoRYwBVJpVbdAGY=; b=nwia0yKPrKYrVn7QjJyR84m67PVb++m+tmqasVpJD9mcFsgZP4DcfLbPMNr5IE3rIe jIY5MxNluWRQUjAUxw57gzqvSeOo5E7nnCdng8pmYxxUGNjJ2hEm80Qp7ettrCBfKPLN 5c5ao9232Vs9dq7okJq4X570C1icrm/TOaG5Kk9Tnse82p/fYhwHdIZfyDtuRT2FNa83 7qk6P15vTubAtOAEIBHrRUaVvFgqdYV/4I8ZaEDjnoVx1Qmo3TlpQyjL9ln5fQhWbVPe N8grb0D/GX836QioErEUNlH76HRDwbgH095RyNDBasv2Hw10/hKrJ0NniHfI2RjMJDzv 49dA== X-Gm-Message-State: AOJu0YxgLdTjaY95qns+QJOkYFK8B8kBhXO25FlmBITYeoV3lOul1nrq akKZiNa2u0ZWX6f979+z+GxM+uCOtXfOgqXqv7ipZs3nG++eGgCH34cQH7Hp00M1WzcN+PBV14y if+sJ89O/T3MzsoN/tz+OZPgZ30tQ8NgFng== X-Received: by 2002:a05:600c:198a:b0:408:40e2:773b with SMTP id t10-20020a05600c198a00b0040840e2773bmr13356415wmq.34.1698301451536; Wed, 25 Oct 2023 23:24:11 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGkpC0X/onri7JsN2JP/+jmWO90nyta4weGQlQ/Lii/zn8t51fz2l+gZzvHUwNcb8CmBltETQ== X-Received: by 2002:a05:600c:198a:b0:408:40e2:773b with SMTP id t10-20020a05600c198a00b0040840e2773bmr13356400wmq.34.1698301451130; Wed, 25 Oct 2023 23:24:11 -0700 (PDT) Date: Thu, 26 Oct 2023 02:24:06 -0400 From: "Michael S. Tsirkin" To: Parav Pandit Cc: Cornelia Huck , "virtio-comment@lists.oasis-open.org" , "hengqi@linux.alibaba.com" , "xuanzhuo@linux.alibaba.com" , Shahaf Shuler Message-ID: <20231026022349-mutt-send-email-mst@kernel.org> References: <87wmvdbehg.fsf@redhat.com> <87ttqhbcy7.fsf@redhat.com> <20231025062207-mutt-send-email-mst@kernel.org> <20231026013059-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] RE: [PATCH v3 2/2] content: Support enabling virtqueue after DRIVER_OK stage On Thu, Oct 26, 2023 at 06:02:28AM +0000, Parav Pandit wrote: > > > > From: Michael S. Tsirkin > > Sent: Thursday, October 26, 2023 11:10 AM > > > > > shorter: i.e. after FEATURES_OK is set and before DRIVER_OK is set. > > Ok. > > > If VIRTIO_F_RING_DYNAMIC is negotiated, > > the driver can choose to enable some virtqueues after DRIVER_OK is set. > Ok. will take this simpler version. > > > > > > > > > > > > > > +enable every virtqueue it wants to use before setting the > > > > > > +DRIVER_OK status bit; the driver can choose to enable a > > > > > > +virtqueue even after the driver has set the DRIVER_OK status bit. > > > > > > > > > > >> The virtqueue enable > > > > > > +mechanism is > > > > > > transport specific. > > > > > > > > > > I still feel there is no real explanation in a transport agnostic manner what does > > it mean to "enable" virtqueue. Do you maybe just mean "configure virtqueue"? > > > There is explanation of "re-enabling" a virtqueue in section " Virtqueue Re-enable". > > There is no good example of "configured" in generic section either, other than cleanup and mmio section. > > > > > Can we just avoid talking about "enabling"? > > Is it true that you can basically change anything you want about the vq not just > > the enable bit? If so talking about enabling is just confusing I think. > Not really. > Enabling sequence of a virtqueue for pci and mmio transport is: > > 1. select a q > 2. program the addresses > 3. set the enable bit > > However, as I think more, this one-way interface of driver instructing the device without any error code and without any response is just too limiting interface. > I will be dropping this series that misuses the config registers beyond its intended init time use. > > Let me work on more mature interface that solves following challenges. > 1. ability to create a virtqueue dynamically after driver_ok > 2. ability to create virtqueue with one or multiple physical addresses > 3. ability for the device to return error if it cannot create dynamic vq creation > > The question is, do we need this generic facility beyond virtio-net? Wow, sounds rather complex. -- MST 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/