From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 19B7B5A845 for ; Mon, 18 Dec 2023 17:33:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="KF8kz8Kq" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1702920782; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=GfgmirgpPKx36i//2L3nndaHAF0yKMBiEStk+Rn60Bw=; b=KF8kz8KqF7QOMR7YTm3mmwuLxg/vcFXiNu0Tto5v9tXIg6iSYgN8/aNxuXrkty6v5Z08X6 UUUDtHkEE1oYFLaI26JjT42mNG6boaTKVCutk9HOFbPrbqOUsDRhqtdbG8hDCSFChRTo1S BGPS4YW/cSqyL2oaveSDE9JumJDf9Hs= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-197-olLSW3VNMJyLDAW25oVy4w-1; Mon, 18 Dec 2023 12:33:00 -0500 X-MC-Unique: olLSW3VNMJyLDAW25oVy4w-1 Received: by mail-wm1-f72.google.com with SMTP id 5b1f17b1804b1-40c295f59ceso21644715e9.0 for ; Mon, 18 Dec 2023 09:33:00 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702920779; x=1703525579; h=content-transfer-encoding:in-reply-to:organization:autocrypt:from :references:cc:to:content-language:subject:user-agent:mime-version :date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=GfgmirgpPKx36i//2L3nndaHAF0yKMBiEStk+Rn60Bw=; b=lUnciY1H+qTWn7vLM6r/e5d6HEAAwpp2Io9E/GU5EeThczfpX8Xmiy777XDJD40qhl eRHgA9EzcQ7Aek1TSGEIIIxAjkJXo8csYcY3ldu3+yX6opAgHqhhAGRDERyls5Bm3WgO E3vysBFVXzetCsyFj7frkBN6O0F3cBtnAiK4LhmN50ClO85EP3IB02IvXOeVhNQjH7bm uua7DmQ4ydOxyOnyl5n3Pk+k9TJLb4ia3VQglQA8cGxnxtLer18JXoPym62X5YyAPN+R 41c0yioVjYY2EoSWct/jBkE275rZlSkFvMHN7NhtNeGgJ1nnH/HxVNGC1dyqf3S/nMdm VNkg== X-Gm-Message-State: AOJu0YwQQtxbwYq1YeYn5DqC6Vvrdh/zbe10kmnMJTws93CvGsbSuO4i +7Pue+2mAIbkbu/AX+Dy8n7ArZqwVoJdDvyZ5XgRN5IffAwPI84UiKu30JaSELswf5ObUPavqrV jpFFn6p7fZDd70eGh1M6DdUjKU4bTWurB X-Received: by 2002:a05:600c:1c8b:b0:405:2d29:1648 with SMTP id k11-20020a05600c1c8b00b004052d291648mr8777171wms.19.1702920779190; Mon, 18 Dec 2023 09:32:59 -0800 (PST) X-Google-Smtp-Source: AGHT+IHXM7mmyeRcbopD4bV2LKBQXTZxL+mkAjFbsm9//GKOEGnciblOC/C/g6Ld0XEPDnk8aY63MA== X-Received: by 2002:a05:600c:1c8b:b0:405:2d29:1648 with SMTP id k11-20020a05600c1c8b00b004052d291648mr8777163wms.19.1702920778651; Mon, 18 Dec 2023 09:32:58 -0800 (PST) Received: from ?IPV6:2003:cb:c72b:b500:b53e:6e32:1408:27ac? (p200300cbc72bb500b53e6e32140827ac.dip0.t-ipconnect.de. [2003:cb:c72b:b500:b53e:6e32:1408:27ac]) by smtp.gmail.com with ESMTPSA id s8-20020a5d5108000000b003366fb71297sm218452wrt.81.2023.12.18.09.32.57 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 18 Dec 2023 09:32:58 -0800 (PST) Message-ID: Date: Mon, 18 Dec 2023 18:32:57 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] virtio_balloon: stay awake while adjusting balloon Content-Language: en-US To: David Stevens , "Michael S . Tsirkin" Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org References: <20231218151842.2756673-1-stevensd@google.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt WNyWQQ== Organization: Red Hat In-Reply-To: <20231218151842.2756673-1-stevensd@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 18.12.23 16:18, David Stevens wrote: > From: David Stevens > > A virtio_balloon's parent device may be configured so that a > configuration change interrupt is a wakeup event. Extend the processing > of such a wakeup event until the balloon finishes inflating or deflating > by calling pm_stay_awake/pm_relax in the virtio_balloon driver. Note > that these calls are no-ops if the parent device doesn't support wakeup > events or if the wakeup events are not enabled. > > This change allows the guest to use system power states such as s2idle > without running the risk the virtio_balloon's cooperative memory > management becoming unresponsive to the host's requests. > > Signed-off-by: David Stevens > --- > v1 -> v2: > - Use adjustment_signal_pending flag instead of a sequence number > - Call pm_stay_awake/pm_relax on parent device instead of adding a wake > event to the virtio balloon device > > drivers/virtio/virtio_balloon.c | 57 +++++++++++++++++++++++++++------ > 1 file changed, 47 insertions(+), 10 deletions(-) > > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c > index 1fe93e93f5bc..a3c11159cbe0 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; > + bool adjustment_signal_pending; > + bool adjustment_in_progress; > }; > > static const struct virtio_device_id id_table[] = { > @@ -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); > } > > +static void start_update_balloon_size(struct virtio_balloon *vb) > +{ > + unsigned long flags; > + > + spin_lock_irqsave(&vb->adjustment_lock, flags); > + vb->adjustment_signal_pending = true; > + if (!vb->adjustment_in_progress) { > + vb->adjustment_in_progress = true; > + pm_stay_awake(vb->vdev->dev.parent); > + } > + 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) > +{ > + spin_lock(&vb->adjustment_lock); > + if (!vb->adjustment_signal_pending && vb->adjustment_in_progress) { How could vb->adjustment_in_progress ever not be set at this point? > + vb->adjustment_in_progress = false; > + pm_relax(vb->vdev->dev.parent); > + } > + spin_unlock(&vb->adjustment_lock); > +} > + LGTM, although I wonder what happens when calling pm_stay_awake() etc. on a parent device that is not wakeup-even-capable? -- Cheers, David / dhildenb