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=-6.9 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 0252FC04A6B for ; Wed, 8 May 2019 14:46:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C8CFA2183E for ; Wed, 8 May 2019 14:46:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727399AbfEHOqV (ORCPT ); Wed, 8 May 2019 10:46:21 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:51016 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727367AbfEHOqU (ORCPT ); Wed, 8 May 2019 10:46:20 -0400 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x48Ebgr4020110 for ; Wed, 8 May 2019 10:46:20 -0400 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0a-001b2d01.pphosted.com with ESMTP id 2sc0kfj511-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 08 May 2019 10:46:19 -0400 Received: from localhost by e06smtp05.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) Wed, 8 May 2019 15:46:14 +0100 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x48EkDeY61341860 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 8 May 2019 14:46:13 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 00ACC42041; Wed, 8 May 2019 14:46:13 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3D32042047; Wed, 8 May 2019 14:46:12 +0000 (GMT) Received: from [9.145.42.10] (unknown [9.145.42.10]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 8 May 2019 14:46:12 +0000 (GMT) Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH 09/10] virtio/s390: use DMA memory for ccw I/O and classic notifiers To: Halil Pasic , kvm@vger.kernel.org, linux-s390@vger.kernel.org, Cornelia Huck , Martin Schwidefsky , Sebastian Ott Cc: virtualization@lists.linux-foundation.org, "Michael S. Tsirkin" , Christoph Hellwig , Thomas Huth , Christian Borntraeger , Viktor Mihajlovski , Vasily Gorbik , Janosch Frank , Claudio Imbrenda , Farhan Ali , Eric Farman References: <20190426183245.37939-1-pasic@linux.ibm.com> <20190426183245.37939-10-pasic@linux.ibm.com> From: Pierre Morel Date: Wed, 8 May 2019 16:46:12 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190426183245.37939-10-pasic@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19050814-0020-0000-0000-0000033A9497 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19050814-0021-0000-0000-0000218D3642 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-05-08_08:,, 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-1905080092 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 26/04/2019 20:32, Halil Pasic wrote: > Before virtio-ccw could get away with not using DMA API for the pieces of > memory it does ccw I/O with. With protected virtualization this has to > change, since the hypervisor needs to read and sometimes also write these > pieces of memory. > > The hypervisor is supposed to poke the classic notifiers, if these are > used, out of band with regards to ccw I/O. So these need to be allocated > as DMA memory (which is shared memory for protected virtualization > guests). > > Let us factor out everything from struct virtio_ccw_device that needs to > be DMA memory in a satellite that is allocated as such. > > Note: The control blocks of I/O instructions do not need to be shared. > These are marshalled by the ultravisor. > > Signed-off-by: Halil Pasic > --- > drivers/s390/virtio/virtio_ccw.c | 177 +++++++++++++++++++++------------------ > 1 file changed, 96 insertions(+), 81 deletions(-) > > diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c > index 1f3e7d56924f..613b18001a0c 100644 > --- a/drivers/s390/virtio/virtio_ccw.c > +++ b/drivers/s390/virtio/virtio_ccw.c > @@ -46,9 +46,15 @@ struct vq_config_block { > #define VIRTIO_CCW_CONFIG_SIZE 0x100 > /* same as PCI config space size, should be enough for all drivers */ > > +struct vcdev_dma_area { > + unsigned long indicators; > + unsigned long indicators2; > + struct vq_config_block config_block; > + __u8 status; > +}; > + > struct virtio_ccw_device { > struct virtio_device vdev; > - __u8 *status; > __u8 config[VIRTIO_CCW_CONFIG_SIZE]; > struct ccw_device *cdev; > __u32 curr_io; > @@ -58,24 +64,22 @@ struct virtio_ccw_device { > spinlock_t lock; > struct mutex io_lock; /* Serializes I/O requests */ > struct list_head virtqueues; > - unsigned long indicators; > - unsigned long indicators2; > - struct vq_config_block *config_block; > bool is_thinint; > bool going_away; > bool device_lost; > unsigned int config_ready; > void *airq_info; > + struct vcdev_dma_area *dma_area; > }; > > static inline unsigned long *indicators(struct virtio_ccw_device *vcdev) > { > - return &vcdev->indicators; > + return &vcdev->dma_area->indicators; > } > > static inline unsigned long *indicators2(struct virtio_ccw_device *vcdev) > { > - return &vcdev->indicators2; > + return &vcdev->dma_area->indicators2; > } > > struct vq_info_block_legacy { > @@ -176,6 +180,22 @@ static struct virtio_ccw_device *to_vc_device(struct virtio_device *vdev) > return container_of(vdev, struct virtio_ccw_device, vdev); > } > > +static inline void *__vc_dma_alloc(struct virtio_device *vdev, size_t size) > +{ > + return ccw_device_dma_zalloc(to_vc_device(vdev)->cdev, size); > +} > + > +static inline void __vc_dma_free(struct virtio_device *vdev, size_t size, > + void *cpu_addr) > +{ > + return ccw_device_dma_free(to_vc_device(vdev)->cdev, cpu_addr, size); > +} > + > +#define vc_dma_alloc_struct(vdev, ptr) \ > + ({ptr = __vc_dma_alloc(vdev, sizeof(*(ptr))); }) > +#define vc_dma_free_struct(vdev, ptr) \ > + __vc_dma_free(vdev, sizeof(*(ptr)), (ptr)) > + > static void drop_airq_indicator(struct virtqueue *vq, struct airq_info *info) > { > unsigned long i, flags; > @@ -335,8 +355,7 @@ static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev, > struct airq_info *airq_info = vcdev->airq_info; > > if (vcdev->is_thinint) { > - thinint_area = kzalloc(sizeof(*thinint_area), > - GFP_DMA | GFP_KERNEL); > + vc_dma_alloc_struct(&vcdev->vdev, thinint_area); > if (!thinint_area) > return; > thinint_area->summary_indicator = > @@ -347,8 +366,8 @@ static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev, > ccw->cda = (__u32)(unsigned long) thinint_area; > } else { > /* payload is the address of the indicators */ > - indicatorp = kmalloc(sizeof(indicators(vcdev)), > - GFP_DMA | GFP_KERNEL); > + indicatorp = __vc_dma_alloc(&vcdev->vdev, > + sizeof(indicators(vcdev))); should be sizeof(long) ? This is a recurrent error, but it is not an issue because the size of the indicators is unsigned long as the size of the pointer. Regards, Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany