From patchwork Tue Jul 11 02:59:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yi Liu X-Patchwork-Id: 13308063 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 44FD9EB64DA for ; Tue, 11 Jul 2023 03:00:02 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id CF4C010E2F6; Tue, 11 Jul 2023 02:59:58 +0000 (UTC) Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTPS id AE20310E2FE; Tue, 11 Jul 2023 02:59:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689044393; x=1720580393; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=QMcxklgFwi8HwhkU2DkkJNF6BNV8ijND+kiSA61fEgk=; b=GWThiSMHeIqRwlUXub9rJBhMipAiOo/M5hzZkKJ7kMUD44VDyJsmg+ff vi06tQyswlql6MtvLJJw+887fgbwrSi1OxD3IvT4A1ed4Wbb0qOnnalIJ Z1HA0UQUd259YXjp+rfhR0FLbs4iNOfe9QPJkIm+wnw1zywxEnkPAHMQp yhuONMX52NhI6QgbZ2BArwHTykw+rr4UIccipL4be9FDUt6GhoGRn6kub 4y9tSVKRuTY2YLE4TazihgfoZFFUIOA0ZoqJhXFPZBIa8dzxIxX4AQa6a w7N7G7zcX7Jm0UFjIbEPPdd4UTvawz/zFGWF01Ke6PeGC0zNGfRzQqiwp g==; X-IronPort-AV: E=McAfee;i="6600,9927,10767"; a="361973212" X-IronPort-AV: E=Sophos;i="6.01,195,1684825200"; d="scan'208";a="361973212" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jul 2023 19:59:53 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10767"; a="724250927" X-IronPort-AV: E=Sophos;i="6.01,195,1684825200"; d="scan'208";a="724250927" Received: from 984fee00a4c6.jf.intel.com ([10.165.58.231]) by fmsmga007.fm.intel.com with ESMTP; 10 Jul 2023 19:59:52 -0700 From: Yi Liu To: alex.williamson@redhat.com, jgg@nvidia.com, kevin.tian@intel.com Date: Mon, 10 Jul 2023 19:59:24 -0700 Message-Id: <20230711025928.6438-23-yi.l.liu@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230711025928.6438-1-yi.l.liu@intel.com> References: <20230711025928.6438-1-yi.l.liu@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v14 22/26] vfio: Add VFIO_DEVICE_BIND_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: mjrosato@linux.ibm.com, jasowang@redhat.com, xudong.hao@intel.com, zhenzhong.duan@intel.com, peterx@redhat.com, terrence.xu@intel.com, chao.p.peng@linux.intel.com, linux-s390@vger.kernel.org, yi.l.liu@intel.com, kvm@vger.kernel.org, lulu@redhat.com, yanting.jiang@intel.com, joro@8bytes.org, nicolinc@nvidia.com, yan.y.zhao@intel.com, intel-gfx@lists.freedesktop.org, eric.auger@redhat.com, intel-gvt-dev@lists.freedesktop.org, yi.y.sun@linux.intel.com, clegoate@redhat.com, cohuck@redhat.com, shameerali.kolothum.thodi@huawei.com, suravee.suthikulpanit@amd.com, robin.murphy@arm.com Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" This adds ioctl for userspace to bind device cdev fd to iommufd. VFIO_DEVICE_BIND_IOMMUFD: bind device to an iommufd, hence gain DMA control provided by the iommufd. open_device op is called after bind_iommufd op. Tested-by: Nicolin Chen Tested-by: Matthew Rosato Tested-by: Yanting Jiang Tested-by: Shameer Kolothum Tested-by: Terrence Xu Signed-off-by: Yi Liu --- drivers/vfio/device_cdev.c | 107 +++++++++++++++++++++++++++++++++++++ drivers/vfio/vfio.h | 13 +++++ drivers/vfio/vfio_main.c | 5 ++ include/linux/vfio.h | 5 +- include/uapi/linux/vfio.h | 27 ++++++++++ 5 files changed, 155 insertions(+), 2 deletions(-) diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c index bf1032d00107..f40784dd5561 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" @@ -45,6 +46,112 @@ int vfio_device_fops_cdev_open(struct inode *inode, struct file *filep) return ret; } +static void vfio_df_get_kvm_safe(struct vfio_device_file *df) +{ + spin_lock(&df->kvm_ref_lock); + vfio_device_get_kvm_safe(df->device, df->kvm); + spin_unlock(&df->kvm_ref_lock); +} + +long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df, + struct vfio_device_bind_iommufd __user *arg) +{ + struct vfio_device *device = df->device; + struct vfio_device_bind_iommufd bind; + unsigned long minsz; + int ret; + + static_assert(__same_type(arg->out_devid, df->devid)); + + minsz = offsetofend(struct vfio_device_bind_iommufd, out_devid); + + if (copy_from_user(&bind, arg, minsz)) + return -EFAULT; + + if (bind.argsz < minsz || bind.flags || bind.iommufd < 0) + return -EINVAL; + + /* BIND_IOMMUFD only allowed for cdev fds */ + if (df->group) + return -EINVAL; + + ret = vfio_device_block_group(device); + if (ret) + return ret; + + mutex_lock(&device->dev_set->lock); + /* one device cannot be bound twice */ + if (df->access_granted) { + ret = -EINVAL; + goto out_unlock; + } + + df->iommufd = iommufd_ctx_from_fd(bind.iommufd); + if (IS_ERR(df->iommufd)) { + ret = PTR_ERR(df->iommufd); + df->iommufd = NULL; + goto out_unlock; + } + + /* + * Before the 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_df_get_kvm_safe(df); + + ret = vfio_df_open(df); + if (ret) + goto out_put_kvm; + + ret = copy_to_user(&arg->out_devid, &df->devid, + sizeof(df->devid)) ? -EFAULT : 0; + if (ret) + goto out_close_device; + + device->cdev_opened = true; + /* + * Paired with smp_load_acquire() in vfio_device_fops::ioctl/ + * read/write/mmap + */ + smp_store_release(&df->access_granted, true); + mutex_unlock(&device->dev_set->lock); + return 0; + +out_close_device: + vfio_df_close(df); +out_put_kvm: + vfio_device_put_kvm(device); + iommufd_ctx_put(df->iommufd); + df->iommufd = NULL; +out_unlock: + mutex_unlock(&device->dev_set->lock); + vfio_device_unblock_group(device); + return ret; +} + +void vfio_df_unbind_iommufd(struct vfio_device_file *df) +{ + struct vfio_device *device = df->device; + + /* + * In the time of close, there is no contention with another one + * changing this flag. So read df->access_granted without lock + * and no smp_load_acquire() is ok. + */ + if (!df->access_granted) + return; + + mutex_lock(&device->dev_set->lock); + vfio_df_close(df); + vfio_device_put_kvm(device); + iommufd_ctx_put(df->iommufd); + device->cdev_opened = false; + mutex_unlock(&device->dev_set->lock); + vfio_device_unblock_group(device); +} + 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 c2aa65382592..137d3e9ca798 100644 --- a/drivers/vfio/vfio.h +++ b/drivers/vfio/vfio.h @@ -287,6 +287,9 @@ static inline void vfio_device_del(struct vfio_device *device) } int vfio_device_fops_cdev_open(struct inode *inode, struct file *filep); +long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df, + struct vfio_device_bind_iommufd __user *arg); +void vfio_df_unbind_iommufd(struct vfio_device_file *df); int vfio_cdev_init(struct class *device_class); void vfio_cdev_cleanup(void); #else @@ -310,6 +313,16 @@ static inline int vfio_device_fops_cdev_open(struct inode *inode, return 0; } +static inline long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df, + struct vfio_device_bind_iommufd __user *arg) +{ + return -EOPNOTSUPP; +} + +static inline void vfio_df_unbind_iommufd(struct vfio_device_file *df) +{ +} + 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 a2744cb64c6d..9fdf93ff17cf 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -575,6 +575,8 @@ static int vfio_device_fops_release(struct inode *inode, struct file *filep) if (df->group) vfio_df_group_close(df); + else + vfio_df_unbind_iommufd(df); vfio_device_put_registration(device); @@ -1149,6 +1151,9 @@ static long vfio_device_fops_unl_ioctl(struct file *filep, void __user *uptr = (void __user *)arg; int ret; + if (cmd == VFIO_DEVICE_BIND_IOMMUFD) + return vfio_df_ioctl_bind_iommufd(df, uptr); + /* Paired with smp_store_release() following vfio_df_open() */ if (!smp_load_acquire(&df->access_granted)) return -EINVAL; diff --git a/include/linux/vfio.h b/include/linux/vfio.h index e0069f26488d..d6228c839c44 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -64,8 +64,9 @@ struct vfio_device { void (*put_kvm)(struct kvm *kvm); #if IS_ENABLED(CONFIG_IOMMUFD) struct iommufd_device *iommufd_device; - bool iommufd_attached; + u8 iommufd_attached:1; #endif + u8 cdev_opened:1; }; /** @@ -168,7 +169,7 @@ vfio_iommufd_get_dev_id(struct vfio_device *vdev, struct iommufd_ctx *ictx) static inline bool vfio_device_cdev_opened(struct vfio_device *device) { - return false; + return device->cdev_opened; } /** diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 4c3d548e9c96..098946b23e86 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -897,6 +897,33 @@ struct vfio_device_feature { #define VFIO_DEVICE_FEATURE _IO(VFIO_TYPE, VFIO_BASE + 17) +/* + * VFIO_DEVICE_BIND_IOMMUFD - _IOR(VFIO_TYPE, VFIO_BASE + 18, + * struct vfio_device_bind_iommufd) + * @argsz: User filled size of this data. + * @flags: Must be 0. + * @iommufd: iommufd to bind. + * @out_devid: The device id generated by this bind. devid is a handle for + * this device/iommufd bond and can be used in IOMMUFD commands. + * + * Bind a vfio_device to the specified iommufd. + * + * User is restricted from accessing the device before the binding operation + * is completed. Only allowed on cdev fds. + * + * Unbind is automatically conducted when device fd is closed. + * + * Return: 0 on success, -errno on failure. + */ +struct vfio_device_bind_iommufd { + __u32 argsz; + __u32 flags; + __s32 iommufd; + __u32 out_devid; +}; + +#define VFIO_DEVICE_BIND_IOMMUFD _IO(VFIO_TYPE, VFIO_BASE + 18) + /* * Provide support for setting a PCI VF Token, which is used as a shared * secret between PF and VF drivers. This feature may only be set on a