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 81B1FC4167B for ; Thu, 30 Nov 2023 09:02:31 +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 DEB86217B1 for ; Thu, 30 Nov 2023 09:02:30 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id CFD95986679 for ; Thu, 30 Nov 2023 09:02:30 +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 C20F098666F; Thu, 30 Nov 2023 09:02:30 +0000 (UTC) Mailing-List: contact virtio-comment-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 B4971986671 for ; Thu, 30 Nov 2023 09:02:30 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: QJ7YTeTKM4muHuSMx5lzGg-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701334948; x=1701939748; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=VO+r+nfsIsQKg2F2+UO+QagaKw0vAHQp4N2Q4+RnbsI=; b=NzR/fBYQTflsCs9FOBM4Nqa/vnAztUDGrP6buFsLyZ1qqOCbe5YxUpP5S5/0zjI42X GsLk0+myQ0jkxZzaIjlJgSf31nKgIyCw28M0maTqXziuxcr244tI405yJCqSkru0GzxA EAw4nw0tyQQXhhhfSGfYK7tbsSnn8b6PAMVcEq2x7pyRQmyB3iVCIeYdIxcm1mSfY9/W cFDkYlG+yJuvhvBrVx11JwrHIhCCIPxGfBvdklDhtaXN6CkaHgbxaGLXqsaNXoraJ8vf /z9ssRw8k55e3bR6LySa+zOXpkMD6bfOuXKbs6OhJngAdmxYc30unS4XtHOnfu4MwLud /fLg== X-Gm-Message-State: AOJu0YxcLSnREBQ6uorPfiaMJqXYZ32AEqdEfxdoRExGdqkk5Ba/Wg5M K9t7Hq43Nm+HpCO2ZEYMuYhEuO2tP/i8ZZgyGzuNHXrOycOGuBmcItP1FtfeMAhQMLwEMNIMx9c 6ohKNwZP0/yVpPCyfetMaGUEP6KDniTij217nB0XyBg== X-Received: by 2002:a05:622a:13d1:b0:423:7843:2b4a with SMTP id p17-20020a05622a13d100b0042378432b4amr22081490qtk.50.1701334947872; Thu, 30 Nov 2023 01:02:27 -0800 (PST) X-Google-Smtp-Source: AGHT+IES6CtoXKGLAgSiSaT7z6JKCIkY4Kn3frvfA5N9a9YxzXLmcaZyldKkRP5nHzzdGSASGJdLIA== X-Received: by 2002:a05:622a:13d1:b0:423:7843:2b4a with SMTP id p17-20020a05622a13d100b0042378432b4amr22081469qtk.50.1701334947618; Thu, 30 Nov 2023 01:02:27 -0800 (PST) Date: Thu, 30 Nov 2023 04:02:23 -0500 From: "Michael S. Tsirkin" To: David Stevens Cc: virtio-comment@lists.oasis-open.org, virtio-dev@lists.oasis-open.org Message-ID: <20231130040108-mutt-send-email-mst@kernel.org> References: <20231113061950.122683-1-stevensd@chromium.org> MIME-Version: 1.0 In-Reply-To: <20231113061950.122683-1-stevensd@chromium.org> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Subject: Re: [virtio-comment] [PATCH v2 0/1] Define low power mode for devices On Mon, Nov 13, 2023 at 03:19:49PM +0900, David Stevens wrote: > The virtio spec currently does not include the concept of device power > management. The lack means that there is no good action drivers can take > when they are requested to put the device into a low power state (e.g. > when a guest is entering a system-wide low power state like S0ix/S3). > Stateless devices can be handled - albeit inefficiently - by resetting > and reinitialzing the device. However, stateful devices cannot support > this situation. This patch defines a low power mode for devices that can > be used in this situation. > > Low power mode is mostly defined at the transport layer, and all > device-side power optimizations are optional. This avoids the need for > invasive device-by-device definitions. It also pushes the requirement > onto the device side, to simplify what driver side changes are > necessary to just [1]. Great idea. This couldn't have come at a better time, too. Please do remember to CC reviewers directly in the future, though. > I believe this patch may address the virtio-gpu issue which [2] is > trying to address by avoiding the reset altogether when the guest enters > S3. > > [1] https://lore.kernel.org/lkml/20231113055138.117392-1-stevensd@chromium.org/ > [2] https://lore.kernel.org/lkml/20230919114242.2283646-1-Jiqian.Chen@amd.com/ > > v1 -> v2: > - Define virtio-pci support on top of PCI power management. > - Add more conformance requirements. > > David Stevens (1): > Define a low power mode for devices > > content.tex | 45 +++++++++++++++++++++++++++++++++++++++++++++ > transport-pci.tex | 7 +++++++ > 2 files changed, 52 insertions(+) > > -- > 2.42.0.869.gea05f2083d-goog > > > 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/ > 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/