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 Received: from ws5-mx01.kavi.com (ws5-mx01.kavi.com [34.193.7.191]) (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 CECFBC001DB for ; Mon, 14 Aug 2023 11:29:26 +0000 (UTC) Received: from lists.oasis-open.org (oasis.ws5.connectedcommunity.org [10.110.1.242]) by ws5-mx01.kavi.com (Postfix) with ESMTP id 463EF2AD53 for ; Mon, 14 Aug 2023 11:29:24 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 3E925986447 for ; Mon, 14 Aug 2023 11:29:24 +0000 (UTC) Received: from host09.ws5.connectedcommunity.org (host09.ws5.connectedcommunity.org [10.110.1.97]) by lists.oasis-open.org (Postfix) with QMQP id 30F6E9863A4; Mon, 14 Aug 2023 11:29:24 +0000 (UTC) Mailing-List: contact virtio-dev-help@lists.oasis-open.org; run by ezmlm List-ID: Sender: Precedence: bulk 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 218E698633D; Mon, 14 Aug 2023 11:29:21 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-IronPort-AV: E=McAfee;i="6600,9927,10801"; a="351613517" X-IronPort-AV: E=Sophos;i="6.01,172,1684825200"; d="scan'208";a="351613517" X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10801"; a="803432828" X-IronPort-AV: E=Sophos;i="6.01,172,1684825200"; d="scan'208";a="803432828" From: Zhu Lingshan To: jasowang@redhat.com, mst@redhat.com, eperezma@redhat.com, cohuck@redhat.com Cc: virtio-comment@lists.oasis-open.org, virtio-dev@lists.oasis-open.org, Zhu Lingshan Date: Tue, 15 Aug 2023 03:29:00 +0800 Message-Id: <20230814192904.30062-2-lingshan.zhu@intel.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20230814192904.30062-1-lingshan.zhu@intel.com> References: <20230814192904.30062-1-lingshan.zhu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [virtio-dev] [RFC PATCH 1/5] virtio: introduce SUSPEND bit in device status This patch introudces a new status bit in the device status: SUSPEND. This SUSPEND bit can be used by the driver to suspend a device, in order to stablize the device states and virtqueue states. Its main use case is live migration. Signed-off-by: Jason Wang Signed-off-by: Eugenio PÃrez Signed-off-by: Zhu Lingshan --- content.tex | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/content.tex b/content.tex index 0a62dce..1bb4401 100644 --- a/content.tex +++ b/content.tex @@ -47,6 +47,9 @@ \section{\field{Device Status} Field}\label{sec:Basic Facilities of a Virtio Dev \item[DRIVER_OK (4)] Indicates that the driver is set up and ready to drive the device. +\item[SUSPEND (16)] When VIRTIO_F_SUSPEND is negotiated, indicates that the + device has been suspended by the driver. + \item[DEVICE_NEEDS_RESET (64)] Indicates that the device has experienced an error from which it can't recover. \end{description} @@ -73,6 +76,10 @@ \section{\field{Device Status} Field}\label{sec:Basic Facilities of a Virtio Dev recover by issuing a reset. \end{note} +The driver MUST NOT set SUSPEND if FEATURES_OK is not set. + +When set SUSPEND, the driver MUST re-read \field{device status} to ensure the SUSPEND bit is set. + \devicenormative{\subsection}{Device Status Field}{Basic Facilities of a Virtio Device / Device Status Field} The device MUST NOT consume buffers or send any used buffer @@ -82,6 +89,13 @@ \section{\field{Device Status} Field}\label{sec:Basic Facilities of a Virtio Dev that a reset is needed. If DRIVER_OK is set, after it sets DEVICE_NEEDS_RESET, the device MUST send a device configuration change notification to the driver. +The device MUST ignore SUSPEND if FEATURES_OK is not set. + +The deivce MUST ignore SUSPEND if VIRTIO_F_SUSPEND is not negotiated. + +If VIRTIO_F_SUSPEND is negotiated and SUSPEND is set, the device MUST clear SUSPEND +and resumes operation upon DRIVER_OK. + \section{Feature Bits}\label{sec:Basic Facilities of a Virtio Device / Feature Bits} Each virtio device offers all the features it understands. During @@ -872,6 +886,10 @@ \chapter{Reserved Feature Bits}\label{sec:Reserved Feature Bits} \ref{devicenormative:Basic Facilities of a Virtio Device / Feature Bits} for handling features reserved for future use. + \item[VIRTIO_F_SUSPEND(41)] This feature indicates that the driver can + SUSPEND the device. + See \ref{sec:Basic Facilities of a Virtio Device / Device Status Field}. + \end{description} \drivernormative{\section}{Reserved Feature Bits}{Reserved Feature Bits} -- 2.35.3 --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org