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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C2AAFC43603 for ; Mon, 9 Dec 2019 11:38:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9774520726 for ; Mon, 9 Dec 2019 11:38:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727391AbfLILif (ORCPT ); Mon, 9 Dec 2019 06:38:35 -0500 Received: from plasma6.jpberlin.de ([80.241.56.68]:59459 "EHLO plasma6.jpberlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727326AbfLILif (ORCPT ); Mon, 9 Dec 2019 06:38:35 -0500 Received: from spamfilter03.heinlein-hosting.de (spamfilter03.heinlein-hosting.de [80.241.56.117]) by plasma.jpberlin.de (Postfix) with ESMTP id 4A281A5187; Mon, 9 Dec 2019 12:38:22 +0100 (CET) X-Virus-Scanned: amavisd-new at heinlein-support.de Received: from plasma.jpberlin.de ([80.241.56.68]) by spamfilter03.heinlein-hosting.de (spamfilter03.heinlein-hosting.de [80.241.56.117]) (amavisd-new, port 10030) with ESMTP id xIptlUPz5zZC; Mon, 9 Dec 2019 12:38:21 +0100 (CET) Received: from webmail.opensynergy.com (unknown [217.66.60.5]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (Client CN "webmail.opensynergy.com", Issuer "GeoTrust EV RSA CA 2018" (not verified)) (Authenticated sender: opensynergy@jpberlin.de) by plasma.jpberlin.de (Postfix) with ESMTPSA id A2B3FA0916; Mon, 9 Dec 2019 12:38:20 +0100 (CET) Received: from os-lin-dmo.localnet (10.25.255.1) by MXS02.open-synergy.com (10.25.10.18) with Microsoft SMTP Server (TLS) id 14.3.468.0; Mon, 9 Dec 2019 12:38:20 +0100 From: Dmitry Sepp To: Gerd Hoffmann CC: Keiichi Watanabe , Enrico Granata , , Tomasz Figa , Linux Media Mailing List , Alexandre Courbot , Alex Lau , Dylan Reid , =?ISO-8859-1?Q?St=E9phane?= Marchesin , Pawel Osciak , David Stevens , Hans Verkuil , Daniel Vetter Subject: Re: [virtio-dev] [RFC RESEND] virtio-video: Add virtio video device specification Date: Mon, 9 Dec 2019 12:38:20 +0100 Message-ID: <1970145.L65FEUb58e@os-lin-dmo> Organization: OpenSynergy In-Reply-To: <20191209104615.ulct6p34cn7ypvrz@sirius.home.kraxel.org> References: <20191105191919.167345-1-dmitry.sepp@opensynergy.com> <20191209104615.ulct6p34cn7ypvrz@sirius.home.kraxel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Originating-IP: [10.25.255.1] Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi, On Montag, 9. Dezember 2019 11:46:15 CET Gerd Hoffmann wrote: > Hi, > > > > For (1) you'll simply do a QUEUE_BUFFER. The command carries references > > > to the buffer pages. No resource management needed. > > > > > > For (2) you'll have RESOURCE_CREATE + RESOURCE_DESTROY + QUEUE_RESOURCE, > > > where RESOURCE_CREATE passes the scatter list of buffer pages to the > > > host and QUEUE_RESOURCE will carry just the resource id. > > > > > > For (3) you'll have RESOURCE_IMPORT + RESOURCE_DESTROY + QUEUE_RESOURCE. > > > > Thanks for the clarification. > > On second thought, however, I'm wondering if we should keep all > > RESOURCE controls. > > This should be an option (4). > > Well, that's actually (2), aka "we use RESOURCE_* commands to manage > resources". With the commands in the latest draft that would be: > > (1) RESOURCE_CREATE > (2) RESOURCE_ATTACH_BACKING > (3) RESOURCE_QUEUE (resource can be used multiple times here) > (4) RESOURCE_DETACH_BACKING > (5) RESOURCE_DESTROY > > I'm not sure we need the separate *_BACKING commands. I think we could > also have RESOURCE_CREATE pass the buffer pages scatter list instead. > > Why it is done this way? Just because the design was copied from > virtio-gpu? Or is there some specific reason? Yes, the design was just derived from virtio-gpu at early stages. I do agree we should merge the two steps. > > cheers, > Gerd