From patchwork Thu Sep 1 07:18:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alyssa Ross X-Patchwork-Id: 12962052 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 B3D23ECAAD3 for ; Thu, 1 Sep 2022 07:59:08 +0000 (UTC) Received: from localhost ([::1]:48688 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oTf6R-00088c-IF for qemu-devel@archiver.kernel.org; Thu, 01 Sep 2022 03:59:07 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:46256) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oTeaF-0003hJ-Dh for qemu-devel@nongnu.org; Thu, 01 Sep 2022 03:25:51 -0400 Received: from wout5-smtp.messagingengine.com ([64.147.123.21]:38939) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oTeaC-00080S-K6 for qemu-devel@nongnu.org; Thu, 01 Sep 2022 03:25:51 -0400 Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.west.internal (Postfix) with ESMTP id 1FB343200944; Thu, 1 Sep 2022 03:18:29 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute3.internal (MEProxy); Thu, 01 Sep 2022 03:18:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alyssa.is; h=cc :cc:content-transfer-encoding:date:date:from:from:in-reply-to :message-id:mime-version:reply-to:sender:subject:subject:to:to; s=fm3; t=1662016708; x=1662103108; bh=JxQxLw6B6JE7d86CxPCELN/mM hiuk8xUa49LYOz87Yk=; b=AhkzWMLi9d/u1xAz69bD35sWS31lJnBh/O2DXqyCB 9lUy+vTy0whX5/Zm/OUpYwffFV8eemqAI3LwGQPDmb+F3lcLiWJjUMbVBO1PGJMy 2n+VN6JDARFL17Uz8k+6kHoc1a/3WOQi0gZNhyBqPAm8HLUHUWG+RELlFOH8PmKJ TH9HaLjfJfGgY7bjtNt1XVz7x4awho7DxIvPi6lHDg0Zq9V/r9O1JLzhCLrNZNkE 2Ankseg05DuZf5fn1xoP5mgYovQDZxbGibMtr+cHbgM1yiw/YV6WISQK5Iv1RYwc JWZo6NeBt3389RU6CtClykUFYEFCQnOfwLCqK6yITj7Ug== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding:date:date :feedback-id:feedback-id:from:from:in-reply-to:message-id :mime-version:reply-to:sender:subject:subject:to:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; t= 1662016708; x=1662103108; bh=JxQxLw6B6JE7d86CxPCELN/mMhiuk8xUa49 LYOz87Yk=; b=xNtDVUkLLzD1tEp84F8Oo/qRHT785+LS2E+QGmP7j7i27agzWBS yMzAJD67Iqs7mE12lnvCOfEv3K/cxT12oAQl9wxLt4Kx8TMDiOQrnmDAi6tNyq+M TJ8jH3axa3vogpTic35E2kSRk3rBo+UBw1iX2EY0hXYYgiTMepeHGfH6NV4KJO5Z O77Y+ionMZBTx5aXZR8PM/Y7/erQRZNQZFfJmphz1q/BwIOAfZZvCXZUM3LgEfIU TMK8wLHU/p/lcb3bWgXZO5ODO4D1dwrzLQYzLqHf3MafJGN9RsC9cB/La/wKoFjU sdN4idVmmiL9K9uVgsZjG3TrTdeGcfnrZew== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvfedrvdekjedguddvudcutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecunecujfgurhephffvvefufffkofgggfestdekre dtredttdenucfhrhhomheptehlhihsshgrucftohhsshcuoehhihesrghlhihsshgrrdhi sheqnecuggftrfgrthhtvghrnhepueefiedvheffveegieejjeevgfejjeduveekffeive euvedvtedvhfelieeutdfgnecuffhomhgrihhnpehkvghrnhgvlhdrohhrghenucevlhhu shhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehqhihlihhsshesgi dvvddtrdhqhihlihhsshdrnhgvth X-ME-Proxy: Feedback-ID: i12284293:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Thu, 1 Sep 2022 03:18:28 -0400 (EDT) Received: by x220.qyliss.net (Postfix, from userid 1000) id 8BEC4566; Thu, 1 Sep 2022 07:18:26 +0000 (UTC) From: Alyssa Ross To: qemu-devel@nongnu.org Cc: "Michael S . Tsirkin" Subject: [PATCH] docs: clarify absence of set_features in vhost-user Date: Thu, 1 Sep 2022 07:18:03 +0000 Message-Id: <20220901071803.273291-1-hi@alyssa.is> X-Mailer: git-send-email 2.37.1 MIME-Version: 1.0 Received-SPF: softfail client-ip=64.147.123.21; envelope-from=qyliss@x220.qyliss.net; helo=wout5-smtp.messagingengine.com X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.25, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_PASS=-0.001, SPF_SOFTFAIL=0.665, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The previous wording was (at least to me) ambiguous about whether a backend should enable features immediately after they were set using VHOST_USER_SET_PROTOCOL_FEATURES, or wait for support for protocol features to be acknowledged if it hasn't been yet before enabling those features. This patch attempts to make it clearer that VHOST_USER_SET_PROTOCOL_FEATURES should immediately enable features, even if support for protocol features has not yet been acknowledged, while still also making clear that the frontend SHOULD acknowledge support for protocol features. Previous discussion begins here: Cc: Michael S. Tsirkin Signed-off-by: Alyssa Ross --- docs/interop/vhost-user.rst | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) base-commit: e93ded1bf6c94ab95015b33e188bc8b0b0c32670 diff --git a/docs/interop/vhost-user.rst b/docs/interop/vhost-user.rst index 3f18ab424e..c8b9771a16 100644 --- a/docs/interop/vhost-user.rst +++ b/docs/interop/vhost-user.rst @@ -906,9 +906,9 @@ Front-end message types ``VHOST_USER_SET_FEATURES``. .. Note:: - Back-ends that report ``VHOST_USER_F_PROTOCOL_FEATURES`` must - support this message even before ``VHOST_USER_SET_FEATURES`` was - called. + While QEMU should acknowledge ``VHOST_USER_F_PROTOCOL_FEATURES``, a + back-end must allow ``VHOST_USER_GET_PROTOCOL_FEATURES`` even if + ``VHOST_USER_F_PROTOCOL_FEATURES`` has not been acknowledged yet. ``VHOST_USER_SET_PROTOCOL_FEATURES`` :id: 16 @@ -923,8 +923,12 @@ Front-end message types ``VHOST_USER_SET_FEATURES``. .. Note:: - Back-ends that report ``VHOST_USER_F_PROTOCOL_FEATURES`` must support - this message even before ``VHOST_USER_SET_FEATURES`` was called. + While QEMU should acknowledge ``VHOST_USER_F_PROTOCOL_FEATURES``, a + back-end must allow ``VHOST_USER_SET_PROTOCOL_FEATURES`` even if + ``VHOST_USER_F_PROTOCOL_FEATURES`` has not been acknowledged yet. + The back-end must not wait for ``VHOST_USER_SET_FEATURES`` before + enabling protocol features requested with + ``VHOST_USER_SET_PROTOCOL_FEATURES``. ``VHOST_USER_SET_OWNER`` :id: 3