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 C57D3EE14C3 for ; Thu, 7 Sep 2023 01:51:32 +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 1469BEEA11 for ; Thu, 7 Sep 2023 01:51:32 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 087C6986603 for ; Thu, 7 Sep 2023 01:51:32 +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 F05499865EB; Thu, 7 Sep 2023 01:51:31 +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 DB3209865E9; Thu, 7 Sep 2023 01:51:26 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-IronPort-AV: E=McAfee;i="6600,9927,10825"; a="441218883" X-IronPort-AV: E=Sophos;i="6.02,233,1688454000"; d="scan'208";a="441218883" X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10825"; a="831943461" X-IronPort-AV: E=Sophos;i="6.02,233,1688454000"; d="scan'208";a="831943461" Message-ID: Date: Thu, 7 Sep 2023 09:51:19 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Firefox/102.0 Thunderbird/102.14.0 Content-Language: en-US To: "Michael S. Tsirkin" Cc: jasowang@redhat.com, eperezma@redhat.com, cohuck@redhat.com, stefanha@redhat.com, virtio-comment@lists.oasis-open.org, virtio-dev@lists.oasis-open.org References: <20230906081637.32185-1-lingshan.zhu@intel.com> <20230906042851-mutt-send-email-mst@kernel.org> <20230906094742-mutt-send-email-mst@kernel.org> From: "Zhu, Lingshan" In-Reply-To: <20230906094742-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: [virtio-dev] Re: [virtio-comment] [PATCH 0/5] virtio: introduce SUSPEND bit and vq state On 9/6/2023 9:49 PM, Michael S. Tsirkin wrote: > On Wed, Sep 06, 2023 at 04:38:44PM +0800, Zhu, Lingshan wrote: >> >> On 9/6/2023 4:29 PM, Michael S. Tsirkin wrote: >>> On Wed, Sep 06, 2023 at 04:16:32PM +0800, Zhu Lingshan wrote: >>>> This series introduces >>>> 1)a new SUSPEND bit in the device status >>>> Which is used to suspend the device, so that the device states >>>> and virtqueue states are stabilized. >>>> >>>> 2)virtqueue state and its accessor, to get and set last_avail_idx >>>> and last_used_idx of virtqueues. >>>> >>>> The main usecase of these new facilities is Live Migration. >>>> >>>> Future work: dirty page tracking and in-flight descriptors. >>> oh that answers my question - it's not covered. >>> I don't think we can merge this without in-flight descriptor >>> support. >> When SUSPEND, we require the device wait until all descriptors that >> being processed to finish and mark them as used.(In patch 2) >> at this point there may be no in-flight descriptors, so this is still >> self-consistent. The tracker for in-flight descriptors is excluded to >> make this series small and focus. > Does not work generally. > Imagine RX ring of a network device for example. You can wait > as long as you can but if there's no incoming network traffic > buffers will not be used. Yes we will include a patch tracking in-flight descriptors in V2. > > Also please, keep to the spec terminology. buffers are used not > descriptors. Best to keep it straight errors will not leak into > spec. OK > > >>> >>> >>>> This series addresses many comments from Jason, Stefan and Eugenio >>>> from RFC series. >>>> >>>> Zhu Lingshan (5): >>>> virtio: introduce vq state as basic facility >>>> virtio: introduce SUSPEND bit in device status >>>> virtqueue: constraints for virtqueue state >>>> virtqueue: ignore resetting vqs when SUSPEND >>>> virtio-pci: implement VIRTIO_F_QUEUE_STATE >>>> >>>> content.tex | 118 ++++++++++++++++++++++++++++++++++++++++++++++ >>>> transport-pci.tex | 18 +++++++ >>>> 2 files changed, 136 insertions(+) >>>> >>>> -- >>>> 2.35.3 >>>> >>>> >>>> This publicly archived list offers a means to provide input to the >>>> OASIS Virtual I/O Device (VIRTIO) TC. >>>> >>>> In order to verify user consent to the Feedback License terms and >>>> to minimize spam in the list archive, subscription is required >>>> before posting. >>>> >>>> Subscribe: virtio-comment-subscribe@lists.oasis-open.org >>>> Unsubscribe: virtio-comment-unsubscribe@lists.oasis-open.org >>>> List help: virtio-comment-help@lists.oasis-open.org >>>> List archive: https://lists.oasis-open.org/archives/virtio-comment/ >>>> Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf >>>> List Guidelines: https://www.oasis-open.org/policies-guidelines/mailing-lists >>>> Committee: https://www.oasis-open.org/committees/virtio/ >>>> Join OASIS: https://www.oasis-open.org/join/ >>>> --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org