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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 A70B8C4338F for ; Thu, 29 Jul 2021 18:53:47 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6F7E160F46 for ; Thu, 29 Jul 2021 18:53:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6F7E160F46 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BDEAE6EE1E; Thu, 29 Jul 2021 18:53:46 +0000 (UTC) Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by gabe.freedesktop.org (Postfix) with ESMTPS id 374076EE1E for ; Thu, 29 Jul 2021 18:53:46 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10060"; a="212679459" X-IronPort-AV: E=Sophos;i="5.84,279,1620716400"; d="scan'208";a="212679459" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Jul 2021 11:53:45 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.84,279,1620716400"; d="scan'208";a="476515452" Received: from orsmsx603.amr.corp.intel.com ([10.22.229.16]) by fmsmga008.fm.intel.com with ESMTP; 29 Jul 2021 11:53:45 -0700 Received: from orsmsx611.amr.corp.intel.com (10.22.229.24) by ORSMSX603.amr.corp.intel.com (10.22.229.16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2242.10; Thu, 29 Jul 2021 11:53:44 -0700 Received: from orsmsx611.amr.corp.intel.com (10.22.229.24) by ORSMSX611.amr.corp.intel.com (10.22.229.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2242.10; Thu, 29 Jul 2021 11:53:44 -0700 Received: from orsmsx611.amr.corp.intel.com ([10.22.229.24]) by ORSMSX611.amr.corp.intel.com ([10.22.229.24]) with mapi id 15.01.2242.010; Thu, 29 Jul 2021 11:53:44 -0700 From: "Kasireddy, Vivek" To: Gerd Hoffmann Subject: RE: [RFC v1 2/4] virtio-gpu uapi: Add VIRTIO_GPU_F_OUT_FENCE feature Thread-Topic: [RFC v1 2/4] virtio-gpu uapi: Add VIRTIO_GPU_F_OUT_FENCE feature Thread-Index: AQHXhFPnb9rpKvlN0Eut27TVkUFkUKtaKwmAgAAfXWA= Date: Thu, 29 Jul 2021 18:53:44 +0000 Message-ID: <6ffb3ea1b5e94af1af04b3c133c7e45f@intel.com> References: <20210729081659.2255499-1-vivek.kasireddy@intel.com> <20210729081659.2255499-3-vivek.kasireddy@intel.com> <20210729095033.js2i6bjk27itcvhg@sirius.home.kraxel.org> In-Reply-To: <20210729095033.js2i6bjk27itcvhg@sirius.home.kraxel.org> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-product: dlpe-windows dlp-version: 11.5.1.3 dlp-reaction: no-action x-originating-ip: [10.1.200.100] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "dri-devel@lists.freedesktop.org" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Gerd, >=20 > On Thu, Jul 29, 2021 at 01:16:57AM -0700, Vivek Kasireddy wrote: > > This feature enables the Guest to wait to know when a resource > > is completely consumed by the Host. >=20 > virtio spec update? >=20 > What are the exact semantics? [Kasireddy, Vivek] As of now, this is still a RFC version. If everyone (Wes= ton Upstream, drm upstream and you) agree that this is a reasonable way to solve https://gitlab.freedesktop.org/wayland/weston/-/issues/514 then I'd g= o=20 ahead and send out the spec updates and cleaner versions of these patches -= - with more documentation. >=20 > Why a new command? Can't you simply fence one of the commands sent > anyway (set_scanout probably for page-flip updates)? [Kasireddy, Vivek] Yes, I think I could add a fence (and an out_fence) to s= et-scanout-blob.=20 >=20 > (feature flag is probably needed even in case we don't need a new > command to make sure the host sends the completion when processing > the command is actually done, i.e. in case of qemu the recently added > fence support is there). [Kasireddy, Vivek] The recently added fence support was for resource_flush = and specifically for GTK-UI or similar backends. I tried using the same mechani= sm for Wayland-UI backend but ran into the above Weston issue. This feature (OUT_F= ENCE) is a potential solution for this issue. Thanks, Vivek >=20 > take care, > Gerd