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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham 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 48C30C282CE for ; Tue, 9 Apr 2019 11:29:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0EB5B2133D for ; Tue, 9 Apr 2019 11:29:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726513AbfDIL3g (ORCPT ); Tue, 9 Apr 2019 07:29:36 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:43668 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726388AbfDIL3f (ORCPT ); Tue, 9 Apr 2019 07:29:35 -0400 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x39BKQWR131548 for ; Tue, 9 Apr 2019 07:29:34 -0400 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0b-001b2d01.pphosted.com with ESMTP id 2rrtcr0h0q-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 09 Apr 2019 07:29:34 -0400 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 9 Apr 2019 12:29:31 +0100 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x39BTTg452953160 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 9 Apr 2019 11:29:29 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 86CA6A4054; Tue, 9 Apr 2019 11:29:29 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 160C6A405C; Tue, 9 Apr 2019 11:29:29 +0000 (GMT) Received: from oc2783563651 (unknown [9.152.224.40]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 9 Apr 2019 11:29:29 +0000 (GMT) Date: Tue, 9 Apr 2019 13:29:27 +0200 From: Halil Pasic To: Cornelia Huck Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, Martin Schwidefsky , Sebastian Ott , virtualization@lists.linux-foundation.org, Christian Borntraeger , Viktor Mihajlovski , Vasily Gorbik , Janosch Frank , Claudio Imbrenda , Farhan Ali , Eric Farman Subject: Re: [RFC PATCH 02/12] virtio/s390: DMA support for virtio-ccw In-Reply-To: <20190409115743.26e51b81.cohuck@redhat.com> References: <20190404231622.52531-1-pasic@linux.ibm.com> <20190404231622.52531-3-pasic@linux.ibm.com> <20190409115743.26e51b81.cohuck@redhat.com> Organization: IBM X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.31; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 19040911-0028-0000-0000-0000035EE371 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19040911-0029-0000-0000-0000241E015C Message-Id: <20190409132927.5df3bc50@oc2783563651> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-04-09_04:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904090074 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, 9 Apr 2019 11:57:43 +0200 Cornelia Huck wrote: > On Fri, 5 Apr 2019 01:16:12 +0200 > Halil Pasic wrote: > > > Currently we have a problem if a virtio-ccw device has > > VIRTIO_F_IOMMU_PLATFORM. > > Can you please describe what the actual problem is? > Without this patch: WARNING: CPU: 2 PID: 26 at [..]/kernel/dma/mapping.c:251 dma_alloc_attrs+0x8e/0xd0 Modules linked in: CPU: 2 PID: 26 Comm: kworker/u6:1 Not tainted 5.1.0-rc3-00023-g1ec89ec #596 Hardware name: IBM 2964 NC9 712 (KVM/Linux) Workqueue: events_unbound async_run_entry_fn Krnl PSW : 0704c00180000000 000000000021b18e (dma_alloc_attrs+0x8e/0xd0) R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 Krnl GPRS: 0000000000000000 0000000000000000 0000000000000000 0000000000001406 000003e00040f838 0000000000002dc0 0000000000000100 0000000000000001 0000000000001000 000000000236f028 000003e00040f838 0000000000001406 000000004b289828 0000000000000080 000003e00040f6f8 000003e00040f6a0 Krnl Code: 000000000021b17e: f0e00004ebaf srp 4(15,%r0),2991(%r14),0 000000000021b184: f0c0000407f4 srp 4(13,%r0),2036,0 #000000000021b18a: a7f40001 brc 15,21b18c >000000000021b18e: ec5520bc0055 risbg %r5,%r5,32,188,0 000000000021b194: b9020011 ltgr %r1,%r1 000000000021b198: a784ffd9 brc 8,21b14a 000000000021b19c: e31010000002 ltg %r1,0(%r1) 000000000021b1a2: a7840012 brc 8,21b1c6 Call Trace: ([<0000000000000004>] 0x4) [<00000000007a7d54>] vring_alloc_queue+0x74/0x90 [<00000000007a8390>] vring_create_virtqueue+0xf8/0x288 [<0000000000919ec0>] virtio_ccw_find_vqs+0xf8/0x950 [<000000000080772e>] init_vq+0x16e/0x318 [<00000000008087c4>] virtblk_probe+0xf4/0xb58 [<00000000007a62a6>] virtio_dev_probe+0x1a6/0x250 [<00000000007ea498>] really_probe+0x1c8/0x290 [<00000000007ea746>] driver_probe_device+0x86/0x160 [<00000000007e7cba>] bus_for_each_drv+0x7a/0xc0 [<00000000007ea23c>] __device_attach+0xfc/0x180 [<00000000007e9116>] bus_probe_device+0xae/0xc8 [<00000000007e5066>] device_add+0x3fe/0x698 [<00000000007a5d92>] register_virtio_device+0xca/0x120 [<00000000009195a2>] virtio_ccw_online+0x1b2/0x220 [<000000000089853e>] ccw_device_set_online+0x1d6/0x4d8 [<0000000000918cf6>] virtio_ccw_auto_online+0x26/0x58 [<00000000001a61b6>] async_run_entry_fn+0x5e/0x158 [<0000000000199322>] process_one_work+0x25a/0x668 [<000000000019977a>] worker_thread+0x4a/0x428 [<00000000001a1ae8>] kthread+0x150/0x170 [<0000000000aeab3a>] kernel_thread_starter+0x6/0xc [<0000000000aeab34>] kernel_thread_starter+0x0/0xc [..] virtio_ccw 0.0.0301: no vq ---[ end trace d35815958c12cad3 ]--- virtio_ccw 0.0.0300: no vq virtio_blk: probe of virtio1 failed with error -12 virtio_blk: probe of virtio3 failed with error -12 Means virtio devices broken. Should I s/we have a problem if a virtio-ccw device/virtio-ccw devices do not work if the device/ ? > > In future we do want to support DMA API with > > virtio-ccw. > > > > Let us do the plumbing, so the feature VIRTIO_F_IOMMU_PLATFORM works > > with virtio-ccw. > > > > Let us also switch from legacy avail/used accessors to the DMA aware > > ones (even if it isn't strictly necessary). > > I think with this change we can remove the legacy accessors, if I > didn't mis-grep. > That is possible, I can do that in v1. > > > > Signed-off-by: Halil Pasic > > --- > > drivers/s390/virtio/virtio_ccw.c | 23 +++++++++++++++++------ > > 1 file changed, 17 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c > > index edf4afe2d688..5956c9e820bb 100644 > > --- a/drivers/s390/virtio/virtio_ccw.c > > +++ b/drivers/s390/virtio/virtio_ccw.c > > @@ -66,6 +66,7 @@ struct virtio_ccw_device { > > bool device_lost; > > unsigned int config_ready; > > void *airq_info; > > + __u64 dma_mask; > > u64? > Right, has nothing to do with userspace. > > }; > > > > struct vq_info_block_legacy { > > @@ -536,8 +537,8 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev, > > info->info_block->s.desc = queue; > > info->info_block->s.index = i; > > info->info_block->s.num = info->num; > > - info->info_block->s.avail = (__u64)virtqueue_get_avail(vq); > > - info->info_block->s.used = (__u64)virtqueue_get_used(vq); > > + info->info_block->s.avail = (__u64)virtqueue_get_avail_addr(vq); > > + info->info_block->s.used = (__u64)virtqueue_get_used_addr(vq); > > ccw->count = sizeof(info->info_block->s); > > } > > ccw->cmd_code = CCW_CMD_SET_VQ; > > @@ -769,10 +770,8 @@ static u64 virtio_ccw_get_features(struct virtio_device *vdev) > > static void ccw_transport_features(struct virtio_device *vdev) > > { > > /* > > - * Packed ring isn't enabled on virtio_ccw for now, > > - * because virtio_ccw uses some legacy accessors, > > - * e.g. virtqueue_get_avail() and virtqueue_get_used() > > - * which aren't available in packed ring currently. > > + * There shouldn't be anything that precludes supporting paced. > > s/paced/packed/ Thx! > > > + * TODO: Remove the limitation after having another look into this. > > */ > > __virtio_clear_bit(vdev, VIRTIO_F_RING_PACKED); > > } > > @@ -1255,6 +1254,18 @@ static int virtio_ccw_online(struct ccw_device *cdev) > > ret = -ENOMEM; > > goto out_free; > > } > > + vcdev->vdev.dev.parent = &cdev->dev; > > That one makes sense, pci and mmio are doing that as well. > > > + cdev->dev.dma_mask = &vcdev->dma_mask; > > That one feels a bit weird. Will this change in one of the follow-on > patches? (Have not yet looked at the whole series.) I don't thinks so. Do you mean this should happen within the cio code? I think I started out with the idea to keep the scope as narrow as possible. Do you have any suggestions? > > > + > > + ret = dma_set_mask_and_coherent(&cdev->dev, DMA_BIT_MASK(64)); > > + if (ret) > > + ret = dma_set_mask_and_coherent(&cdev->dev, > > + DMA_BIT_MASK(32)); > > + if (ret) { > > + dev_warn(&cdev->dev, "Failed to enable 64-bit or 32-bit DMA. Trying to continue, but this might not work.\n"); > > This does not look like you'd try to continue? > I remember now. First I did continue, then I changed this to fail hard so I can not ignore any such problems while smoke testing ('I don't always check the kernel messages'), but kept the old message. This basically should not fail anyway, otherwise we have a problem AFAIU. By the way virtio-pci tries to continue indeed, and this is also where the wording comes from ;). What would you prefer? Try to continue or fail right away? Regards, Halil > > + goto out_free; > > + } > > + > > vcdev->config_block = kzalloc(sizeof(*vcdev->config_block), > > GFP_DMA | GFP_KERNEL); > > if (!vcdev->config_block) { >