From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f200.google.com (mail-pf1-f200.google.com [209.85.210.200]) by kanga.kvack.org (Postfix) with ESMTP id 231A88E0001 for ; Fri, 28 Dec 2018 01:36:26 -0500 (EST) Received: by mail-pf1-f200.google.com with SMTP id m3so22644553pfj.14 for ; Thu, 27 Dec 2018 22:36:26 -0800 (PST) Received: from mga02.intel.com (mga02.intel.com. [134.134.136.20]) by mx.google.com with ESMTPS id y5si35149463pgk.49.2018.12.27.22.36.24 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 27 Dec 2018 22:36:24 -0800 (PST) Message-ID: <5C25C5A5.4080706@intel.com> Date: Fri, 28 Dec 2018 14:41:41 +0800 From: Wei Wang MIME-Version: 1.0 Subject: Re: [PATCH v37 0/3] Virtio-balloon: support free page reporting References: <1535333539-32420-1-git-send-email-wei.w.wang@intel.com> <0661b05a-d9d0-d374-44e8-2583463e94c2@de.ibm.com> In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Christian Borntraeger , virtio-dev@lists.oasis-open.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-mm@kvack.org, mst@redhat.com, mhocko@kernel.org, akpm@linux-foundation.org, dgilbert@redhat.com Cc: torvalds@linux-foundation.org, pbonzini@redhat.com, liliang.opensource@gmail.com, yang.zhang.wz@gmail.com, quan.xu0@gmail.com, nilal@redhat.com, riel@redhat.com, peterx@redhat.com, quintela@redhat.com, Halil Pasic , Cornelia Huck On 12/27/2018 08:17 PM, Christian Borntraeger wrote: > > On 27.12.2018 12:59, Christian Borntraeger wrote: >> On 27.12.2018 12:31, Christian Borntraeger wrote: >>> This patch triggers random crashes in the guest kernel on s390 early during boot. >>> No migration and no setting of the balloon is involved. >>> >> Adding Conny and Halil, >> >> As the QEMU provides no PAGE_HINT feature yet, this quick hack makes the >> guest boot fine again: >> >> >> diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c >> index 728ecd1eea305..aa2e1864c5736 100644 >> --- a/drivers/virtio/virtio_balloon.c >> +++ b/drivers/virtio/virtio_balloon.c >> @@ -492,7 +492,7 @@ static int init_vqs(struct virtio_balloon *vb) >> callbacks[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL; >> } >> >> - err = vb->vdev->config->find_vqs(vb->vdev, VIRTIO_BALLOON_VQ_MAX, >> + err = vb->vdev->config->find_vqs(vb->vdev, 3, //VIRTIO_BALLOON_VQ_MAX, >> vqs, callbacks, names, NULL, NULL); >> if (err) >> return err; >> >> >> To me it looks like that virtio_ccw_find_vqs will abort if any of the virtqueues >> that it is been asked for does not exist (including the earlier ones). >> > This "hack" makes the random crashes go away, but the balloon interface itself > does not work. (setting the value to anything will hang the guest). > As patch 1 also modifies the main path, there seem to be additional issues, maybe > endianess > > Looking at things like > > + vb->cmd_id_received = VIRTIO_BALLOON_CMD_ID_STOP; > + vb->cmd_id_active = cpu_to_virtio32(vb->vdev, > + VIRTIO_BALLOON_CMD_ID_STOP); > + vb->cmd_id_stop = cpu_to_virtio32(vb->vdev, > + VIRTIO_BALLOON_CMD_ID_STOP); > > > Why is cmd_id_received not using cpu_to_virtio32? > That conversion is only needed when we need to send the value to the device. cmd_id_received doesn't need to be sent to the device. Best, Wei 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 X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 89CC8C43387 for ; Fri, 28 Dec 2018 06:36:27 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 36CDB208E4 for ; Fri, 28 Dec 2018 06:36:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 36CDB208E4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 726B38E0033; Fri, 28 Dec 2018 01:36:26 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 6FDB38E0001; Fri, 28 Dec 2018 01:36:26 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 614688E0033; Fri, 28 Dec 2018 01:36:26 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from mail-pf1-f200.google.com (mail-pf1-f200.google.com [209.85.210.200]) by kanga.kvack.org (Postfix) with ESMTP id 231A88E0001 for ; Fri, 28 Dec 2018 01:36:26 -0500 (EST) Received: by mail-pf1-f200.google.com with SMTP id m3so22644553pfj.14 for ; Thu, 27 Dec 2018 22:36:26 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:message-id :date:from:user-agent:mime-version:to:cc:subject:references :in-reply-to:content-transfer-encoding; bh=lsXK23dY/JXgKOo8tBzVcrl1k8jDNuM8wtmUeWrgOrQ=; b=j9h/FK9TDWCogyTDBoJCHQZ/lTph+8yJC6KEBWN7Vl89Ih5fuGaztfdz0/G0B+REqL eiPF+AOqXd2W8y2GozslfqsIzRGBAmxM/EV1tR5y/lhI5d9Pe2AnoCjqAm9Q7SxXzn1Y +WhrirdNrUYluefnmUosV/psGndM9Mcp3UqtSNAjUQeT9uJa19eXTGNpoF/i9m4DqY/5 /gVfo8405gTI0mL7q4g+zAldFSaUPbeYzGvp+EBSAKEYyO4t1TjcgKQo0fGVItum1MQf P2nK3Pka4Tv5ImBPuu57xGcSAtucUNuwC294jQQxIDxkErGhCFGI6s4Heq7npwrlzbvW pqcQ== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of wei.w.wang@intel.com designates 134.134.136.20 as permitted sender) smtp.mailfrom=wei.w.wang@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Gm-Message-State: AJcUukfxj4ZxH8o9yHYvJpr5PoreU3uZK0zMYbMg+TC33f7g2SfwRmhv ErFmyPgOUxBz5v6jz9p7cgriUVb5zoj/Ny/Tu+M2tUFcYjUiNNXe4E3uh8aJZeTn4aNc4v7mkbG xvAmwm7PgJspY9bEROkRTssuai39UJ7CDWVwW0qMUdzL7NQSb5kOsfA58z3C2Bn8wZw== X-Received: by 2002:a65:6392:: with SMTP id h18mr25687879pgv.107.1545978985730; Thu, 27 Dec 2018 22:36:25 -0800 (PST) X-Google-Smtp-Source: ALg8bN4L7N2aa4DUNiMeiehLYTqgWrVWdZvNJT0qLsmVkoH2Eii4myLWqhWB68kCrPflEMSnhA4e X-Received: by 2002:a65:6392:: with SMTP id h18mr25687849pgv.107.1545978984697; Thu, 27 Dec 2018 22:36:24 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1545978984; cv=none; d=google.com; s=arc-20160816; b=Iwo6xQOc+g2jbmnalpjuZEGGKdS7DeKvumnxASxvxZvULXA6H+GHVt5qJdRlC51MJD IKDLTFJ5Qr/zSEE1jyEZbIHMK0XBw8UkRyDmmlLuUAHOOyfViDKo+UFVI1EvF1vudng8 9AY5V0JhH7/0Z8vUtY81ty7T8lyKo8fRbtJOctaMfBedTIXyize0ybjLNCkHMOAl/Y+t g3Uaf1OZ7HZAvC4+cI8WEHPoEgzhvarTIcBSPKEyA7hWMOq7mBGUlb0WEDxXZQX53ZUM WRHEwIGHFF5xKRXsM4++J+iu+9xxcH2d5A+beA7+J29IOX8NIxplp6zhyR+QQr0cB8MT OgDQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:in-reply-to:references:subject:cc:to :mime-version:user-agent:from:date:message-id; bh=lsXK23dY/JXgKOo8tBzVcrl1k8jDNuM8wtmUeWrgOrQ=; b=QTl6tU2etvx0i1GAQNVjlWLxOYVb/F4S0iF2y0iyBUMmHqAJQer390aFMz1s9W4H0S K0DrVUX0pKIpnP5o23GzSt//HlLS6VX3yL9QtPoIe/UiitnFCvVd9YpZi93Qe5WNhroa pW+1j+K6bLBijYIfrSyfU8p/6/2NkaO7YadV4XXc6z3HvAfSpQScE97ygRC7GFLoGJKn blXzXDG2O6nS1XjuP3mn+ToB6xN+aKMIwO8DZrN4rWVKj51UdiI+g18/rChbzvcCALTY ihhWpQOXBXzSmzXUl6e0f5OAN1dXATXMvdi9atuqI8NxNMUcVQ4eCzg2NMOgWazfJQlP Kurg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of wei.w.wang@intel.com designates 134.134.136.20 as permitted sender) smtp.mailfrom=wei.w.wang@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from mga02.intel.com (mga02.intel.com. [134.134.136.20]) by mx.google.com with ESMTPS id y5si35149463pgk.49.2018.12.27.22.36.24 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 27 Dec 2018 22:36:24 -0800 (PST) Received-SPF: pass (google.com: domain of wei.w.wang@intel.com designates 134.134.136.20 as permitted sender) client-ip=134.134.136.20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of wei.w.wang@intel.com designates 134.134.136.20 as permitted sender) smtp.mailfrom=wei.w.wang@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Dec 2018 22:36:23 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,408,1539673200"; d="scan'208";a="131208853" Received: from unknown (HELO [10.239.13.114]) ([10.239.13.114]) by fmsmga004.fm.intel.com with ESMTP; 27 Dec 2018 22:36:20 -0800 Message-ID: <5C25C5A5.4080706@intel.com> Date: Fri, 28 Dec 2018 14:41:41 +0800 From: Wei Wang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Christian Borntraeger , virtio-dev@lists.oasis-open.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-mm@kvack.org, mst@redhat.com, mhocko@kernel.org, akpm@linux-foundation.org, dgilbert@redhat.com CC: torvalds@linux-foundation.org, pbonzini@redhat.com, liliang.opensource@gmail.com, yang.zhang.wz@gmail.com, quan.xu0@gmail.com, nilal@redhat.com, riel@redhat.com, peterx@redhat.com, quintela@redhat.com, Halil Pasic , Cornelia Huck Subject: Re: [PATCH v37 0/3] Virtio-balloon: support free page reporting References: <1535333539-32420-1-git-send-email-wei.w.wang@intel.com> <0661b05a-d9d0-d374-44e8-2583463e94c2@de.ibm.com> In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format="flowed" Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Message-ID: <20181228064141.VdlKaIh8eDCsMgt4ifA9e9o6jgUONNPcdelHCvDqjYo@z> On 12/27/2018 08:17 PM, Christian Borntraeger wrote: > > On 27.12.2018 12:59, Christian Borntraeger wrote: >> On 27.12.2018 12:31, Christian Borntraeger wrote: >>> This patch triggers random crashes in the guest kernel on s390 early during boot. >>> No migration and no setting of the balloon is involved. >>> >> Adding Conny and Halil, >> >> As the QEMU provides no PAGE_HINT feature yet, this quick hack makes the >> guest boot fine again: >> >> >> diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c >> index 728ecd1eea305..aa2e1864c5736 100644 >> --- a/drivers/virtio/virtio_balloon.c >> +++ b/drivers/virtio/virtio_balloon.c >> @@ -492,7 +492,7 @@ static int init_vqs(struct virtio_balloon *vb) >> callbacks[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL; >> } >> >> - err = vb->vdev->config->find_vqs(vb->vdev, VIRTIO_BALLOON_VQ_MAX, >> + err = vb->vdev->config->find_vqs(vb->vdev, 3, //VIRTIO_BALLOON_VQ_MAX, >> vqs, callbacks, names, NULL, NULL); >> if (err) >> return err; >> >> >> To me it looks like that virtio_ccw_find_vqs will abort if any of the virtqueues >> that it is been asked for does not exist (including the earlier ones). >> > This "hack" makes the random crashes go away, but the balloon interface itself > does not work. (setting the value to anything will hang the guest). > As patch 1 also modifies the main path, there seem to be additional issues, maybe > endianess > > Looking at things like > > + vb->cmd_id_received = VIRTIO_BALLOON_CMD_ID_STOP; > + vb->cmd_id_active = cpu_to_virtio32(vb->vdev, > + VIRTIO_BALLOON_CMD_ID_STOP); > + vb->cmd_id_stop = cpu_to_virtio32(vb->vdev, > + VIRTIO_BALLOON_CMD_ID_STOP); > > > Why is cmd_id_received not using cpu_to_virtio32? > That conversion is only needed when we need to send the value to the device. cmd_id_received doesn't need to be sent to the device. Best, Wei