From nobody Thu Nov 13 10:28:32 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=linux.intel.com ARC-Seal: i=1; a=rsa-sha256; t=1579587687; cv=none; d=zohomail.com; s=zohoarc; b=dvGtJt6fgxW/O6vFfMhoKvlUde12ILJ2WG+ILBGtHxoBv/V300WTREqmKxyo2wQmCAg/9tgbfuVbSwEHUT4C2We0P4h0IS4x7hkB5nVKzlS6KGzsVEC/dza5Jrhsikv9HSLpxexsaOmIAW+ogYkM4q9NEFLBVJrztRHzWkJKgik= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1579587687; h=Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:Message-ID:References:Sender:Subject:To; bh=B4IA3p8zj/5cZ+N4TrBvlDWS8wD6Z0GU79R+S7gn/vw=; b=cdHiAlY28yJ+aJq7x9AKrZ8Vc2JuK45GM7HWTrQMza/KpkHXXpSGzBzw9K2zqHp2JIeM2Qh1DxEbrSE5TjozmxTQHGbJLMKmUMSHc0BR9LJZlC6EffELW0CliKwLQi5aceQFLGHOhPGEEE1NGTqSKYhyOVuE1V88DON+PT0y6mA= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1579587687661430.8738342321901; Mon, 20 Jan 2020 22:21:27 -0800 (PST) Received: from localhost ([::1]:48942 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1itmuk-0000Hm-Bl for importer@patchew.org; Tue, 21 Jan 2020 01:21:26 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41969) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1itmtE-0007Ho-9Q for qemu-devel@nongnu.org; Tue, 21 Jan 2020 01:19:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1itmtD-0006Tm-6g for qemu-devel@nongnu.org; Tue, 21 Jan 2020 01:19:52 -0500 Received: from mga03.intel.com ([134.134.136.65]:35723) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1itmtC-0006Rf-UP for qemu-devel@nongnu.org; Tue, 21 Jan 2020 01:19:51 -0500 Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Jan 2020 22:19:50 -0800 Received: from hyperv-sh3.bj.intel.com ([10.240.193.95]) by fmsmga001.fm.intel.com with ESMTP; 20 Jan 2020 22:19:49 -0800 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,344,1574150400"; d="scan'208";a="278302031" From: Jing Liu To: virtio-dev@lists.oasis-open.org Subject: [virtio-dev] [PATCH v2 3/5] virtio-mmio: Add feature bit for MMIO MSI Date: Tue, 21 Jan 2020 21:54:31 +0800 Message-Id: <1579614873-21907-4-git-send-email-jing2.liu@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1579614873-21907-1-git-send-email-jing2.liu@linux.intel.com> References: <1579614873-21907-1-git-send-email-jing2.liu@linux.intel.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.65 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Zha Bin , kvm@vger.kernel.org, Jing Liu , linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, Chao Peng , Liu Jiang Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The current MMIO transport layer uses a single, dedicated interrupt signal, which brings performance penalty. Add a feature bit (40) for introducing MSI capability. Co-developed-by: Chao Peng Signed-off-by: Chao Peng Co-developed-by: Liu Jiang Signed-off-by: Liu Jiang Co-developed-by: Zha Bin Signed-off-by: Zha Bin Signed-off-by: Jing Liu --- content.tex | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/content.tex b/content.tex index 5881253..ff151ba 100644 --- a/content.tex +++ b/content.tex @@ -5840,6 +5840,9 @@ \chapter{Reserved Feature Bits}\label{sec:Reserved Fe= ature Bits} \item[VIRTIO_F_MMIO_NOTIFICATION(39)] This feature indicates that the device supports enhanced notification mechanism on MMIO transport layer. + \item[VIRTIO_F_MMIO_MSI(40)] This feature indicates that the + device supports Message Signal Interrupts (MSI) mechanism on + MMIO transport layer. =20 \drivernormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} =20 @@ -5875,6 +5878,10 @@ \chapter{Reserved Feature Bits}\label{sec:Reserved F= eature Bits} =20 A driver SHOULD accept VIRTIO_F_MMIO_NOTIFICATION if it is offered. =20 +A driver SHOULD accept VIRTIO_F_MMIO_MSI if it is offered. +If VIRTIO_F_MMIO_MSI has been negotiated, a driver MUST try to +set up MSI at first priority. + \devicenormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} =20 A device MUST offer VIRTIO_F_VERSION_1. A device MAY fail to operate furt= her --=20 2.7.4