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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB1A1C74A5B for ; Wed, 29 Mar 2023 21:19:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229596AbjC2VTy (ORCPT ); Wed, 29 Mar 2023 17:19:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46568 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229514AbjC2VTx (ORCPT ); Wed, 29 Mar 2023 17:19:53 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 38E6F19A1 for ; Wed, 29 Mar 2023 14:19:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1680124746; 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; bh=IGVHQslX/4Q2nBwMZykirgQDOWEjwl8r9/yUI1mNVoU=; b=ED62VYFJrSAoNlIGSrg8e7FmD8a8/PoZrjMbcZMnAlVtSuJ443wjeNlpYlP4+cW2uay3OG x3Ap0AKxG9h1QmUgB5Q7uGcQIKW2wyk29CEhghgPLVE69hSY+eVkVtTsZZkRRn2o1yWDCh CicDUJUjG8X0j2ANjJOFVEUO7lTJpL0= Received: from mail-io1-f69.google.com (mail-io1-f69.google.com [209.85.166.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-321-awsJfh3TOcmOa7GFKRsI6w-1; Wed, 29 Mar 2023 17:19:05 -0400 X-MC-Unique: awsJfh3TOcmOa7GFKRsI6w-1 Received: by mail-io1-f69.google.com with SMTP id z65-20020a6bc944000000b007584beb0e28so10216658iof.21 for ; Wed, 29 Mar 2023 14:19:04 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680124744; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=IGVHQslX/4Q2nBwMZykirgQDOWEjwl8r9/yUI1mNVoU=; b=hpCnLCAvBxMwhJ3NEslLLMsicVILxNKd4tFJ1O2DOduBtKny8iOh1Rvi+XEHViyeYg eUTpr1msYQ4/DT73vPCB7OwfFBauxwQEbKQlbBxYPyJibY0EXq88fMQXFMgDIXLPHUxA xONRmKroIeRrPVcmwUlLUmjEApEIW78zui5dZdd/vdky9jk+YMs675lccvuQYBtiH/gC 2FoQfGX6YDnqDMQNr+bBLI4fRQMRjoHJUXZnm3Y4VqrjudhzSF6MWAqGc5s0ySWp7PGj A4S2IyGxltcMf3k4GfPJq4KbvIy20NAu9BqZOY6OVumWgQRNeX1IF+1tdg9nMJhS8ZcR lU+g== X-Gm-Message-State: AAQBX9fMFqDcXM6Bz/7xyWQw7ZlMmUxbFxSY8K+TIOXxMt5TcTkVbWzU VDgrE9kMA2JOtdAbvveRISqsx4bk1FcH5LyIMioLzizY15CCsIFGn5MtjU/qrEVeWjlaVOOYyaU u6DnG8q4YDsZ/O3ODrs6s1g== X-Received: by 2002:a92:d9c6:0:b0:317:99b9:3d1c with SMTP id n6-20020a92d9c6000000b0031799b93d1cmr15068254ilq.26.1680124744092; Wed, 29 Mar 2023 14:19:04 -0700 (PDT) X-Google-Smtp-Source: AKy350ajQ4SKKBVBjAHaP/aw41f4QFgk7HVdYnc6BROfSNFgwlwllegkuthAdtgSC0+A+lGPIbjj7Q== X-Received: by 2002:a92:d9c6:0:b0:317:99b9:3d1c with SMTP id n6-20020a92d9c6000000b0031799b93d1cmr15068243ilq.26.1680124743779; Wed, 29 Mar 2023 14:19:03 -0700 (PDT) Received: from redhat.com ([38.15.36.239]) by smtp.gmail.com with ESMTPSA id cd8-20020a0566381a0800b00406521ad090sm9814930jab.94.2023.03.29.14.19.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Mar 2023 14:19:03 -0700 (PDT) Date: Wed, 29 Mar 2023 15:19:02 -0600 From: Alex Williamson To: Yi Liu Cc: jgg@nvidia.com, kevin.tian@intel.com, joro@8bytes.org, robin.murphy@arm.com, cohuck@redhat.com, eric.auger@redhat.com, nicolinc@nvidia.com, kvm@vger.kernel.org, mjrosato@linux.ibm.com, chao.p.peng@linux.intel.com, yi.y.sun@linux.intel.com, peterx@redhat.com, jasowang@redhat.com, shameerali.kolothum.thodi@huawei.com, lulu@redhat.com, suravee.suthikulpanit@amd.com, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-s390@vger.kernel.org, xudong.hao@intel.com, yan.y.zhao@intel.com, terrence.xu@intel.com, yanting.jiang@intel.com Subject: Re: [PATCH v8 22/24] vfio: Add VFIO_DEVICE_AT[DE]TACH_IOMMUFD_PT Message-ID: <20230329151902.453ed743.alex.williamson@redhat.com> In-Reply-To: <20230327094047.47215-23-yi.l.liu@intel.com> References: <20230327094047.47215-1-yi.l.liu@intel.com> <20230327094047.47215-23-yi.l.liu@intel.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.35; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org Nit, ATDETACH? [AT|DE]TACH? On Mon, 27 Mar 2023 02:40:45 -0700 Yi Liu wrote: > This adds ioctl for userspace to attach device cdev fd to and detach > from IOAS/hw_pagetable managed by iommufd. > > VFIO_DEVICE_ATTACH_IOMMUFD_PT: attach vfio device to IOAS, hw_pagetable > managed by iommufd. Attach can be > undo by VFIO_DEVICE_DETACH_IOMMUFD_PT > or device fd close. > VFIO_DEVICE_DETACH_IOMMUFD_PT: detach vfio device from the current attached > IOAS or hw_pagetable managed by iommufd. > > Reviewed-by: Kevin Tian > Tested-by: Terrence Xu > Tested-by: Nicolin Chen > Tested-by: Matthew Rosato > Signed-off-by: Yi Liu > --- > drivers/vfio/device_cdev.c | 85 ++++++++++++++++++++++++++++++++++++++ > drivers/vfio/vfio.h | 16 +++++++ > drivers/vfio/vfio_main.c | 8 ++++ > include/uapi/linux/vfio.h | 52 +++++++++++++++++++++++ > 4 files changed, 161 insertions(+) > > diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c > index 2b563bac50b9..b5de997bff6d 100644 > --- a/drivers/vfio/device_cdev.c > +++ b/drivers/vfio/device_cdev.c > @@ -197,6 +197,91 @@ long vfio_device_ioctl_bind_iommufd(struct vfio_device_file *df, > return ret; > } > > +int vfio_ioctl_device_attach(struct vfio_device_file *df, > + struct vfio_device_attach_iommufd_pt __user *arg) > +{ > + struct vfio_device *device = df->device; > + struct vfio_device_attach_iommufd_pt attach; > + unsigned long minsz; > + int ret; > + > + static_assert(__same_type(arg->pt_id, attach.pt_id)); Same comment as previous, given these are the same field of the same structure, I don't understand how this could ever assert. > + > + minsz = offsetofend(struct vfio_device_attach_iommufd_pt, pt_id); > + > + if (copy_from_user(&attach, arg, minsz)) > + return -EFAULT; > + > + if (attach.argsz < minsz || attach.flags) > + return -EINVAL; > + > + if (!device->ops->bind_iommufd) > + return -ENODEV; Same as previous, we already require this to enable cdev support, so this seems ultra paranoid. > + > + /* ATTACH only allowed for cdev fds */ > + if (df->group) > + return -EINVAL; > + > + mutex_lock(&device->dev_set->lock); > + /* noiommufd mode doesn't allow attach */ > + if (!df->iommufd) { > + ret = -EOPNOTSUPP; > + goto out_unlock; > + } > + > + ret = device->ops->attach_ioas(device, &attach.pt_id); > + if (ret) > + goto out_unlock; > + > + ret = copy_to_user(&arg->pt_id, &attach.pt_id, > + sizeof(attach.pt_id)) ? -EFAULT : 0; > + if (ret) > + goto out_detach; > + mutex_unlock(&device->dev_set->lock); > + > + return 0; > + > +out_detach: > + device->ops->detach_ioas(device); > +out_unlock: > + mutex_unlock(&device->dev_set->lock); > + return ret; > +} > + > +int vfio_ioctl_device_detach(struct vfio_device_file *df, > + struct vfio_device_detach_iommufd_pt __user *arg) > +{ > + struct vfio_device *device = df->device; > + struct vfio_device_detach_iommufd_pt detach; > + unsigned long minsz; > + > + minsz = offsetofend(struct vfio_device_detach_iommufd_pt, flags); > + > + if (copy_from_user(&detach, arg, minsz)) > + return -EFAULT; > + > + if (detach.argsz < minsz || detach.flags) > + return -EINVAL; > + > + if (!device->ops->bind_iommufd) > + return -ENODEV; > + > + /* DETACH only allowed for cdev fds */ > + if (df->group) > + return -EINVAL; > + > + mutex_lock(&device->dev_set->lock); > + /* noiommufd mode doesn't support detach */ > + if (!df->iommufd) { > + mutex_unlock(&device->dev_set->lock); > + return -EOPNOTSUPP; > + } > + device->ops->detach_ioas(device); > + mutex_unlock(&device->dev_set->lock); > + > + return 0; > +} For both of these, can't a user trigger the WARN_ON(!vdev->iommufd_device) if they call either of these before VFIO_DEVICE_BIND_IOMMUFD? Thanks, Alex > + > static char *vfio_device_devnode(const struct device *dev, umode_t *mode) > { > return kasprintf(GFP_KERNEL, "vfio/devices/%s", dev_name(dev)); > diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h > index ace3d52b0928..c199e410db18 100644 > --- a/drivers/vfio/vfio.h > +++ b/drivers/vfio/vfio.h > @@ -284,6 +284,10 @@ int vfio_device_fops_cdev_open(struct inode *inode, struct file *filep); > void vfio_device_cdev_close(struct vfio_device_file *df); > long vfio_device_ioctl_bind_iommufd(struct vfio_device_file *df, > struct vfio_device_bind_iommufd __user *arg); > +int vfio_ioctl_device_attach(struct vfio_device_file *df, > + struct vfio_device_attach_iommufd_pt __user *arg); > +int vfio_ioctl_device_detach(struct vfio_device_file *df, > + struct vfio_device_detach_iommufd_pt __user *arg); > int vfio_cdev_init(struct class *device_class); > void vfio_cdev_cleanup(void); > #else > @@ -317,6 +321,18 @@ static inline long vfio_device_ioctl_bind_iommufd(struct vfio_device_file *df, > return -EOPNOTSUPP; > } > > +static inline int vfio_ioctl_device_attach(struct vfio_device_file *df, > + struct vfio_device_attach_iommufd_pt __user *arg) > +{ > + return -EOPNOTSUPP; > +} > + > +static inline int vfio_ioctl_device_detach(struct vfio_device_file *df, > + struct vfio_device_detach_iommufd_pt __user *arg) > +{ > + return -EOPNOTSUPP; > +} > + > static inline int vfio_cdev_init(struct class *device_class) > { > return 0; > diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c > index 375086c8803f..896d8bb49585 100644 > --- a/drivers/vfio/vfio_main.c > +++ b/drivers/vfio/vfio_main.c > @@ -1150,6 +1150,14 @@ static long vfio_device_fops_unl_ioctl(struct file *filep, > ret = vfio_ioctl_device_feature(device, (void __user *)arg); > break; > > + case VFIO_DEVICE_ATTACH_IOMMUFD_PT: > + ret = vfio_ioctl_device_attach(df, (void __user *)arg); > + break; > + > + case VFIO_DEVICE_DETACH_IOMMUFD_PT: > + ret = vfio_ioctl_device_detach(df, (void __user *)arg); > + break; > + > default: > if (unlikely(!device->ops->ioctl)) > ret = -EINVAL; > diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h > index 62b2f2497525..bf6c97e759c7 100644 > --- a/include/uapi/linux/vfio.h > +++ b/include/uapi/linux/vfio.h > @@ -231,6 +231,58 @@ struct vfio_device_bind_iommufd { > > #define VFIO_DEVICE_BIND_IOMMUFD _IO(VFIO_TYPE, VFIO_BASE + 19) > > +/* > + * VFIO_DEVICE_ATTACH_IOMMUFD_PT - _IOW(VFIO_TYPE, VFIO_BASE + 20, > + * struct vfio_device_attach_iommufd_pt) > + * > + * Attach a vfio device to an iommufd address space specified by IOAS > + * id or hw_pagetable (hwpt) id. > + * > + * Available only after a device has been bound to iommufd via > + * VFIO_DEVICE_BIND_IOMMUFD > + * > + * Undo by VFIO_DEVICE_DETACH_IOMMUFD_PT or device fd close. > + * > + * @argsz: user filled size of this data. > + * @flags: must be 0. > + * @pt_id: Input the target id which can represent an ioas or a hwpt > + * allocated via iommufd subsystem. > + * Output the attached hwpt id which could be the specified > + * hwpt itself or a hwpt automatically created for the > + * specified ioas by kernel during the attachment. > + * > + * Return: 0 on success, -errno on failure. > + */ > +struct vfio_device_attach_iommufd_pt { > + __u32 argsz; > + __u32 flags; > + __u32 pt_id; > +}; > + > +#define VFIO_DEVICE_ATTACH_IOMMUFD_PT _IO(VFIO_TYPE, VFIO_BASE + 20) > + > +/* > + * VFIO_DEVICE_DETACH_IOMMUFD_PT - _IOW(VFIO_TYPE, VFIO_BASE + 21, > + * struct vfio_device_detach_iommufd_pt) > + * > + * Detach a vfio device from the iommufd address space it has been > + * attached to. After it, device should be in a blocking DMA state. > + * > + * Available only after a device has been bound to iommufd via > + * VFIO_DEVICE_BIND_IOMMUFD. > + * > + * @argsz: user filled size of this data. > + * @flags: must be 0. > + * > + * Return: 0 on success, -errno on failure. > + */ > +struct vfio_device_detach_iommufd_pt { > + __u32 argsz; > + __u32 flags; > +}; > + > +#define VFIO_DEVICE_DETACH_IOMMUFD_PT _IO(VFIO_TYPE, VFIO_BASE + 21) > + > /** > * VFIO_DEVICE_GET_INFO - _IOR(VFIO_TYPE, VFIO_BASE + 7, > * struct vfio_device_info)