From patchwork Mon Feb 6 09:05:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yi Liu X-Patchwork-Id: 13129518 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E82B8C61DA4 for ; Mon, 6 Feb 2023 09:06:13 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4F0B210E352; Mon, 6 Feb 2023 09:06:13 +0000 (UTC) Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by gabe.freedesktop.org (Postfix) with ESMTPS id A27F610E348; Mon, 6 Feb 2023 09:06:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1675674367; x=1707210367; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=v6I4EZeoD/6CjXAdTmYi2jJRJwtVcJIY7HyYwH0QLKU=; b=CmaAITyhrP1N3xLBejMzt3edmxeOQbIeTfq2V4NNfERlC1cmnTDMaF8S ENxlyQlcmxPErp3Dfd354LDcceOGu/VSGJyTS1cbnC8ypcW6iTs31Q3ii GVZQI7o1RaRBC9urTdfU1wlOloOHyXHbWP1/rCOQVH0Fqu+ph+kbhtR4Q H1hcQwD+iX6YYs6ngMXoi32kSdpP8AepR9JIPiXMtYhgi1HB1TtOY5kcx HTuv/RGfYf4Ov1ar0lvHC+/L7b3jNcbghOnDdcMdAeLGzWLX5s7NnPQJQ TiBKAPVH4yscMnUnrw12XKMnDKwWriZALbqO5fvR90u4pcYl1nZotb4hB w==; X-IronPort-AV: E=McAfee;i="6500,9779,10612"; a="309495928" X-IronPort-AV: E=Sophos;i="5.97,276,1669104000"; d="scan'208";a="309495928" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Feb 2023 01:06:07 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10612"; a="911862878" X-IronPort-AV: E=Sophos;i="5.97,276,1669104000"; d="scan'208";a="911862878" Received: from 984fee00a4c6.jf.intel.com ([10.165.58.231]) by fmsmga006.fm.intel.com with ESMTP; 06 Feb 2023 01:06:05 -0800 From: Yi Liu To: alex.williamson@redhat.com, jgg@nvidia.com, kevin.tian@intel.com Date: Mon, 6 Feb 2023 01:05:31 -0800 Message-Id: <20230206090532.95598-14-yi.l.liu@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230206090532.95598-1-yi.l.liu@intel.com> References: <20230206090532.95598-1-yi.l.liu@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v2 13/14] vfio: Add ioctls for device cdev using iommufd X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-s390@vger.kernel.org, yi.l.liu@intel.com, yi.y.sun@linux.intel.com, kvm@vger.kernel.org, mjrosato@linux.ibm.com, jasowang@redhat.com, cohuck@redhat.com, linux-kernel@vger.kernel.org, peterx@redhat.com, eric.auger@redhat.com, nicolinc@nvidia.com, shameerali.kolothum.thodi@huawei.com, suravee.suthikulpanit@amd.com, chao.p.peng@linux.intel.com, lulu@redhat.com, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" This adds three vfio device ioctls for userspace using iommufd to set up secure DMA context for device access. VFIO_DEVICE_BIND_IOMMUFD: bind device to an iommufd, hence gain DMA control provided by the iommufd. VFIO no iommu mode is indicated by passing a minus fd value. VFIO_DEVICE_ATTACH_IOMMUFD_PT: attach 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 device from the current attached IOAS or hw_pagetable managed by iommufd. Signed-off-by: Yi Liu --- drivers/vfio/device_cdev.c | 176 +++++++++++++++++++++++++++++++++++++ drivers/vfio/vfio.h | 33 ++++++- drivers/vfio/vfio_main.c | 47 +++++++++- include/linux/iommufd.h | 6 ++ include/uapi/linux/vfio.h | 86 ++++++++++++++++++ 5 files changed, 343 insertions(+), 5 deletions(-) diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c index f024833c9e2c..4105cc939b7b 100644 --- a/drivers/vfio/device_cdev.c +++ b/drivers/vfio/device_cdev.c @@ -3,6 +3,7 @@ * Copyright (c) 2023 Intel Corporation. */ #include +#include #include "vfio.h" @@ -46,6 +47,181 @@ int vfio_device_fops_open(struct inode *inode, struct file *filep) return ret; } +void vfio_device_cdev_close(struct vfio_device_file *df) +{ + mutex_lock(&df->device->dev_set->lock); + vfio_device_close(df); + vfio_device_put_kvm(df->device); + mutex_unlock(&df->device->dev_set->lock); +} + +static void vfio_device_get_kvm_safe(struct vfio_device_file *df) +{ + spin_lock(&df->kvm_ref_lock); + if (!df->kvm) + goto unlock; + + _vfio_device_get_kvm_safe(df->device, df->kvm); + +unlock: + spin_unlock(&df->kvm_ref_lock); +} + +long vfio_device_ioctl_bind_iommufd(struct vfio_device_file *df, + unsigned long arg) +{ + struct vfio_device *device = df->device; + struct vfio_device_bind_iommufd bind; + struct iommufd_ctx *iommufd = NULL; + unsigned long minsz; + struct fd f; + int ret; + + minsz = offsetofend(struct vfio_device_bind_iommufd, iommufd); + + if (copy_from_user(&bind, (void __user *)arg, minsz)) + return -EFAULT; + + if (bind.argsz < minsz || bind.flags) + return -EINVAL; + + if (!device->ops->bind_iommufd) + return -ENODEV; + + mutex_lock(&device->dev_set->lock); + /* + * If already been bound to an iommufd, or already set noiommu + * then fail it. + */ + if (df->iommufd || df->noiommu) { + ret = -EINVAL; + goto out_unlock; + } + + /* iommufd < 0 means noiommu mode */ + if (bind.iommufd < 0) { + if (!capable(CAP_SYS_RAWIO)) { + ret = -EPERM; + goto out_unlock; + } + df->noiommu = true; + } else { + f = fdget(bind.iommufd); + if (!f.file) { + ret = -EBADF; + goto out_unlock; + } + iommufd = iommufd_ctx_from_file(f.file); + if (IS_ERR(iommufd)) { + ret = PTR_ERR(iommufd); + goto out_put_file; + } + } + + /* + * Before the first device open, get the KVM pointer currently + * associated with the device file (if there is) and obtain a + * reference. This reference is held until device closed. Save + * the pointer in the device for use by drivers. + */ + vfio_device_get_kvm_safe(df); + + df->iommufd = iommufd; + ret = vfio_device_open(df, &bind.out_devid, NULL); + if (ret) + goto out_put_kvm; + + ret = copy_to_user((void __user *)arg + minsz, + &bind.out_devid, + sizeof(bind.out_devid)) ? -EFAULT : 0; + if (ret) + goto out_close_device; + + if (iommufd) + fdput(f); + else if (df->noiommu) + dev_warn(device->dev, "vfio-noiommu device used by user " + "(%s:%d)\n", current->comm, task_pid_nr(current)); + mutex_unlock(&device->dev_set->lock); + return 0; + +out_close_device: + vfio_device_close(df); +out_put_kvm: + vfio_device_put_kvm(device); +out_put_file: + if (iommufd) + fdput(f); +out_unlock: + df->iommufd = NULL; + df->noiommu = false; + mutex_unlock(&device->dev_set->lock); + return ret; +} + +int vfio_ioctl_device_attach(struct vfio_device_file *df, + void __user *arg) +{ + struct vfio_device *device = df->device; + struct vfio_device_attach_iommufd_pt attach; + int ret; + + if (copy_from_user(&attach, (void __user *)arg, sizeof(attach))) + return -EFAULT; + + if (attach.flags || attach.pt_id == IOMMUFD_INVALID_ID) + return -EINVAL; + + if (!device->ops->bind_iommufd) + return -ENODEV; + + mutex_lock(&device->dev_set->lock); + if (df->noiommu) + return -ENODEV; + + ret = device->ops->attach_ioas(device, &attach.pt_id); + if (ret) + goto out_unlock; + + ret = copy_to_user((void __user *)arg + offsetofend( + struct vfio_device_attach_iommufd_pt, flags), + &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, + void __user *arg) +{ + struct vfio_device *device = df->device; + struct vfio_device_detach_iommufd_pt detach; + + if (copy_from_user(&detach, (void __user *)arg, sizeof(detach))) + return -EFAULT; + + if (detach.flags) + return -EINVAL; + + if (!device->ops->bind_iommufd) + return -ENODEV; + + mutex_lock(&device->dev_set->lock); + if (df->noiommu) + return -ENODEV; + device->ops->detach_ioas(device); + mutex_unlock(&device->dev_set->lock); + return 0; +} + 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 c7c75865afec..8a290c1455e1 100644 --- a/drivers/vfio/vfio.h +++ b/drivers/vfio/vfio.h @@ -23,7 +23,9 @@ struct vfio_device_file { bool access_granted; spinlock_t kvm_ref_lock; /* protect kvm field */ struct kvm *kvm; - struct iommufd_ctx *iommufd; /* protected by struct vfio_device_set::lock */ + /* protected by struct vfio_device_set::lock */ + struct iommufd_ctx *iommufd; + bool noiommu; }; void vfio_device_put_registration(struct vfio_device *device); @@ -253,6 +255,13 @@ static inline void vfio_iommufd_unbind(struct vfio_device *device) #if IS_ENABLED(CONFIG_VFIO_DEVICE_CDEV) void vfio_init_device_cdev(struct vfio_device *device); int vfio_device_fops_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, + unsigned long arg); +int vfio_ioctl_device_attach(struct vfio_device_file *df, + void __user *arg); +int vfio_ioctl_device_detach(struct vfio_device_file *df, + void __user *arg); int vfio_cdev_init(struct class *device_class); void vfio_cdev_cleanup(void); #else @@ -266,6 +275,28 @@ static inline int vfio_device_fops_open(struct inode *inode, return 0; } +static inline void vfio_device_cdev_close(struct vfio_device_file *df) +{ +} + +static inline long vfio_device_ioctl_bind_iommufd(struct vfio_device_file *df, + unsigned long arg) +{ + return -EOPNOTSUPP; +} + +static inline int vfio_ioctl_device_attach(struct vfio_device_file *df, + void __user *arg) +{ + return -EOPNOTSUPP; +} + +static inline int vfio_ioctl_device_detach(struct vfio_device_file *df, + void __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 035730dc6ad4..8559c3dfb335 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -37,6 +37,7 @@ #include #include #include +#include #include "vfio.h" #define DRIVER_VERSION "0.3" @@ -442,16 +443,41 @@ static int vfio_device_first_open(struct vfio_device_file *df, { struct vfio_device *device = df->device; struct iommufd_ctx *iommufd = df->iommufd; - int ret; + int ret = 0; lockdep_assert_held(&device->dev_set->lock); + /* df->iommufd and df->noiommu should be exclusive */ + if (WARN_ON(iommufd && df->noiommu)) + return -EINVAL; + if (!try_module_get(device->dev->driver->owner)) return -ENODEV; + /* + * For group path, iommufd pointer is NULL when comes into this + * helper. Its noiommu support is in container.c. + * + * For iommufd compat mode, iommufd pointer here is a valid value. + * Its noiommu support is supposed to be in vfio_iommufd_bind(). + * + * For device cdev path, iommufd pointer here is a valid value for + * normal cases, but it is NULL if it's noiommu. The reason is + * that userspace uses iommufd==-1 to indicate noiommu mode in this + * path. So caller of this helper will pass in a NULL iommufd + * pointer. To differentiate it from the group path which also + * passes NULL iommufd pointer in, df->noiommu is used. For cdev + * noiommu, df->noiommu would be set to mark noiommu case for cdev + * path. + * + * So if df->noiommu is set then this helper just goes ahead to + * open device. If not, it depends on if iommufd pointer is NULL + * to handle the group path, iommufd compat mode, normal cases in + * the cdev path. + */ if (iommufd) ret = vfio_iommufd_bind(device, iommufd, dev_id, pt_id); - else + else if (!df->noiommu) ret = vfio_device_group_use_iommu(device); if (ret) goto err_module_put; @@ -466,7 +492,7 @@ static int vfio_device_first_open(struct vfio_device_file *df, err_unuse_iommu: if (iommufd) vfio_iommufd_unbind(device); - else + else if (!df->noiommu) vfio_device_group_unuse_iommu(device); err_module_put: module_put(device->dev->driver->owner); @@ -484,7 +510,7 @@ static void vfio_device_last_close(struct vfio_device_file *df) device->ops->close_device(device); if (iommufd) vfio_iommufd_unbind(device); - else + else if (!df->noiommu) vfio_device_group_unuse_iommu(device); module_put(device->dev->driver->owner); } @@ -588,6 +614,8 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep) */ if (!df->is_cdev_device) vfio_device_group_close(df); + else + vfio_device_cdev_close(df); vfio_device_put_registration(device); @@ -1162,6 +1190,9 @@ static long vfio_device_fops_unl_ioctl(struct file *filep, bool access; int ret; + if (cmd == VFIO_DEVICE_BIND_IOMMUFD) + return vfio_device_ioctl_bind_iommufd(df, arg); + /* Paired with smp_store_release() in vfio_device_open() */ access = smp_load_acquire(&df->access_granted); if (!access) @@ -1176,6 +1207,14 @@ 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/linux/iommufd.h b/include/linux/iommufd.h index 650d45629647..9672cf839687 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -17,6 +17,12 @@ struct iommufd_ctx; struct iommufd_access; struct file; +/* + * iommufd core init xarray with flags==XA_FLAGS_ALLOC1, so valid + * ID starts from 1. + */ +#define IOMMUFD_INVALID_ID 0 + struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx, struct device *dev, u32 *id); void iommufd_device_unbind(struct iommufd_device *idev); diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 23105eb036fa..c86cfe442884 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -190,6 +190,92 @@ struct vfio_group_status { /* --------------- IOCTLs for DEVICE file descriptors --------------- */ +/* + * VFIO_DEVICE_BIND_IOMMUFD - _IOR(VFIO_TYPE, VFIO_BASE + 19, + * struct vfio_device_bind_iommufd) + * + * Bind a vfio_device to the specified iommufd. + * + * The user should provide a device cookie when calling this ioctl. The + * cookie is carried only in event e.g. I/O fault reported to userspace + * via iommufd. The user should use devid returned by this ioctl to mark + * the target device in other ioctls (e.g. capability query via iommufd). + * + * User is not allowed to access the device before the binding operation + * is completed. + * + * Unbind is automatically conducted when device fd is closed. + * + * @argsz: user filled size of this data. + * @flags: reserved for future extension. + * @dev_cookie: a per device cookie provided by userspace. + * @iommufd: iommufd to bind. iommufd < 0 means noiommu. + * @out_devid: the device id generated by this bind. + * + * Return: 0 on success, -errno on failure. + */ +struct vfio_device_bind_iommufd { + __u32 argsz; + __u32 flags; + __aligned_u64 dev_cookie; + __s32 iommufd; + __u32 out_devid; +}; + +#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)