From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-6675-cohuck=redhat.com@lists.oasis-open.org Sender: 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 CA5E6985F08 for ; Tue, 21 Jan 2020 06:19:52 +0000 (UTC) From: Jing Liu Date: Tue, 21 Jan 2020 21:54:31 +0800 Message-Id: <1579614873-21907-4-git-send-email-jing2.liu@linux.intel.com> 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> Subject: [virtio-dev] [PATCH v2 3/5] virtio-mmio: Add feature bit for MMIO MSI Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable To: virtio-dev@lists.oasis-open.org Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, qemu-devel@nongnu.org, Jing Liu , Chao Peng , Liu Jiang , Zha Bin List-ID: 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 --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org