From nobody Fri Dec 19 13:09:43 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7335CC4167B for ; Mon, 11 Dec 2023 11:44:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234427AbjLKLnw (ORCPT ); Mon, 11 Dec 2023 06:43:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234384AbjLKLnu (ORCPT ); Mon, 11 Dec 2023 06:43:50 -0500 Received: from mail-pl1-x636.google.com (mail-pl1-x636.google.com [IPv6:2607:f8b0:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C0FDBA for ; Mon, 11 Dec 2023 03:43:56 -0800 (PST) Received: by mail-pl1-x636.google.com with SMTP id d9443c01a7336-1d0bb7ff86cso39504235ad.1 for ; Mon, 11 Dec 2023 03:43:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1702295036; x=1702899836; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=HWSOqTGWbN7/1kah/VavpIcFubAITMhMWD90A/nR/50=; b=BahufwEbOMijAkG1weJ7ZlThAFQOgHDbp5s6SdfDUx9hW2LEXAZmVLE4ZeutUfSA+8 eul/jl2J4FnbqqTPpiRBVDXYQgoFfMjA3F/nf7MryI2H2iUnGsFnUClS28vdmK2x1+sb LgNvJBv10scRfMgw6eXu0hu98ND5IHDS4INcs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702295036; x=1702899836; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=HWSOqTGWbN7/1kah/VavpIcFubAITMhMWD90A/nR/50=; b=tTtisKy71Eu7e1wwLd6SyyGHiVf/P8FgJvs3s8185Q1NZNP58d8eBTJxMwNpbt68MH V8dRZ/+bW3QIhrSEj0H9EzAwrm1Uj0dEkGmByVqnf7ognAnHRTaRiNJ8wKqMXamn1qFI u9t++8uW2RDuEXKSLJKWlIl4KWtWmbq+Kqt+wluOr7nHnphdpEuMM73GKGopnvpctzl7 ENTgTaOLOaurfVfKeLDLYO8s5F+RF0GT8N5jhTysrIOAqOsMV5mZqVFgQegBjogKksqt SN8xLrw4ZX8zDsjNuEMCAhFTpeb65lzt5mg/aCgnIDa2mpbYuDUwXqJnGmT/zBIvsTP1 wp0Q== X-Gm-Message-State: AOJu0Yyx/C2qQuNJhVVy0aNrGXn+RP8gCk+z/KkeIfnS78Lk/TF5llcn qN1H3UgUTSpDhLO25o2NIRIgmzLCD4wBpmMdark= X-Google-Smtp-Source: AGHT+IH7Xh1az1wiQpVmjLradIRIrBROYVFJjrZ2ymcEvhmwqw1W9rUCiU1B3MJGvYEVoR+YJZt6iA== X-Received: by 2002:a17:902:ecc4:b0:1d0:7b67:c535 with SMTP id a4-20020a170902ecc400b001d07b67c535mr5058442plh.17.1702295036027; Mon, 11 Dec 2023 03:43:56 -0800 (PST) Received: from localhost ([2401:fa00:8f:203:f046:fcb8:db69:41ed]) by smtp.gmail.com with UTF8SMTPSA id n2-20020a170902d2c200b001cfd0ddc5b9sm6388253plc.262.2023.12.11.03.43.54 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 11 Dec 2023 03:43:55 -0800 (PST) From: David Stevens X-Google-Original-From: David Stevens To: "Michael S . Tsirkin" , David Hildenbrand Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, David Stevens Subject: [PATCH] virtio_balloon: stay awake while adjusting balloon Date: Mon, 11 Dec 2023 20:43:46 +0900 Message-ID: <20231211114346.1132386-1-stevensd@google.com> X-Mailer: git-send-email 2.43.0.472.g3155946c3a-goog MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: David Stevens Add a wakeup event for when the balloon is inflating or deflating. Userspace can enable this wakeup event to prevent the system from suspending while the balloon is being adjusted. This allows /sys/power/wakeup_count to be used without breaking virtio_balloon's cooperative memory management. Signed-off-by: David Stevens --- drivers/virtio/virtio_balloon.c | 59 +++++++++++++++++++++++++++------ 1 file changed, 49 insertions(+), 10 deletions(-) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloo= n.c index 1fe93e93f5bc..811d8937246a 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -119,6 +119,11 @@ struct virtio_balloon { /* Free page reporting device */ struct virtqueue *reporting_vq; struct page_reporting_dev_info pr_dev_info; + + /* State for keeping the wakeup_source active while adjusting the balloon= */ + spinlock_t adjustment_lock; + u32 adjustment_seqno; + bool adjustment_in_progress; }; =20 static const struct virtio_device_id id_table[] =3D { @@ -437,6 +442,31 @@ static void virtio_balloon_queue_free_page_work(struct= virtio_balloon *vb) queue_work(vb->balloon_wq, &vb->report_free_page_work); } =20 +static void start_update_balloon_size(struct virtio_balloon *vb) +{ + unsigned long flags; + + spin_lock_irqsave(&vb->adjustment_lock, flags); + vb->adjustment_seqno++; + if (!vb->adjustment_in_progress) { + vb->adjustment_in_progress =3D true; + pm_stay_awake(&vb->vdev->dev); + } + spin_unlock_irqrestore(&vb->adjustment_lock, flags); + + queue_work(system_freezable_wq, &vb->update_balloon_size_work); +} + +static void end_update_balloon_size(struct virtio_balloon *vb, u32 seqno) +{ + spin_lock(&vb->adjustment_lock); + if (vb->adjustment_seqno =3D=3D seqno && vb->adjustment_in_progress) { + vb->adjustment_in_progress =3D false; + pm_relax(&vb->vdev->dev); + } + spin_unlock(&vb->adjustment_lock); +} + static void virtballoon_changed(struct virtio_device *vdev) { struct virtio_balloon *vb =3D vdev->priv; @@ -444,8 +474,7 @@ static void virtballoon_changed(struct virtio_device *v= dev) =20 spin_lock_irqsave(&vb->stop_update_lock, flags); if (!vb->stop_update) { - queue_work(system_freezable_wq, - &vb->update_balloon_size_work); + start_update_balloon_size(vb); virtio_balloon_queue_free_page_work(vb); } spin_unlock_irqrestore(&vb->stop_update_lock, flags); @@ -473,22 +502,29 @@ static void update_balloon_size_func(struct work_stru= ct *work) { struct virtio_balloon *vb; s64 diff; + u32 seqno; =20 vb =3D container_of(work, struct virtio_balloon, update_balloon_size_work); - diff =3D towards_target(vb); =20 - if (!diff) - return; + spin_lock(&vb->adjustment_lock); + seqno =3D vb->adjustment_seqno; + spin_unlock(&vb->adjustment_lock); =20 - if (diff > 0) - diff -=3D fill_balloon(vb, diff); - else - diff +=3D leak_balloon(vb, -diff); - update_balloon_size(vb); + diff =3D towards_target(vb); + + if (diff) { + if (diff > 0) + diff -=3D fill_balloon(vb, diff); + else + diff +=3D leak_balloon(vb, -diff); + update_balloon_size(vb); + } =20 if (diff) queue_work(system_freezable_wq, work); + else + end_update_balloon_size(vb, seqno); } =20 static int init_vqs(struct virtio_balloon *vb) @@ -992,6 +1028,9 @@ static int virtballoon_probe(struct virtio_device *vde= v) goto out_unregister_oom; } =20 + spin_lock_init(&vb->adjustment_lock); + device_set_wakeup_capable(&vb->vdev->dev, true); + virtio_device_ready(vdev); =20 if (towards_target(vb)) --=20 2.43.0.472.g3155946c3a-goog