From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9DB873D4134; Wed, 8 Apr 2026 18:25:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775672706; cv=none; b=WYStBz4AD8oDk+4M7xiJBiArQGkA/skBWfKeKWjj89zDBtHfHpXa3I/j/bK/BhGBPdj4WjlPzFAC5Rl0QtWFP5D0MeCmP9SWMqT6oLcvYD9YL9S0nohcmgKMpKRpumEcDRA/ki9uSODtNHvQoTn1u4GF6C8wWMQ+ciHuvlDS+VI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775672706; c=relaxed/simple; bh=pq408kuXVjbvhDINshqMRt4oWCr/h9fqJ0rv7UyDNyg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=j9hmt9c1bfey/Dhwx/oZWU7bhM48DdTPEFx/p7jWsdsAz8ymjUKrOkOCD/Q5JKjXusMYwCsC7ncNYYPxtgDwIWDPEO981RNul5thpwQj9FP6eVtvSLqJpYRRNxMzHM9Uf/62EXkKMil+YmwQ99AEGOge4PE9nRLAcW7/QmUU21s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=eLCXt97e; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="eLCXt97e" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B7D15C19421; Wed, 8 Apr 2026 18:25:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1775672706; bh=pq408kuXVjbvhDINshqMRt4oWCr/h9fqJ0rv7UyDNyg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eLCXt97euzDargsXUQN5O6622LSr0y7dCcqBOh3Wx5twrgOqdwDwMGYWOwkfTeYh8 TNibAjn0aRTKMTs7p/8r66zC7541CmwhFwrkGF6Ia+r9NStnSfAmjv70JwGMSiJzmt E7olGu8bmfSgDHnU2CWnf9EjkuKWcPfPKBTee0kM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jason Gunthorpe , Kevin Tian , Alex Williamson , Axel Rasmussen , Tugrul Kukul , Florian Fainelli , "Pavel Machek (CIP)" , Ron Economos , "Justin M. Forbes" , Mark Brown , Conor Dooley , Jon Hunter , Shuah Khan , Peter Schneider , Alex Williamson , Sasha Levin Subject: [PATCH 6.6 111/160] vfio: Create vfio_fs_type with inode per device Date: Wed, 8 Apr 2026 20:03:18 +0200 Message-ID: <20260408175917.326372651@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260408175913.177092714@linuxfoundation.org> References: <20260408175913.177092714@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alex Williamson commit b7c5e64fecfa88764791679cca4786ac65de739e upstream. By linking all the device fds we provide to userspace to an address space through a new pseudo fs, we can use tools like unmap_mapping_range() to zap all vmas associated with a device. Suggested-by: Jason Gunthorpe Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20240530045236.1005864-2-alex.williamson@redhat.com Signed-off-by: Alex Williamson Signed-off-by: Axel Rasmussen Signed-off-by: Tugrul Kukul Tested-by: Florian Fainelli Tested-by: Pavel Machek (CIP) Tested-by: Ron Economos Tested-by: Justin M. Forbes Tested-by: Mark Brown Tested-by: Conor Dooley Tested-by: Jon Hunter Tested-by: Shuah Khan Tested-by: Peter Schneider Reviewed-by: Alex Williamson Acked-by: Alex Williamson Signed-off-by: Sasha Levin --- drivers/vfio/device_cdev.c | 7 ++++++ drivers/vfio/group.c | 7 ++++++ drivers/vfio/vfio_main.c | 44 ++++++++++++++++++++++++++++++++++++++ include/linux/vfio.h | 1 + 4 files changed, 59 insertions(+) diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c index e75da0a70d1f8..bb1817bd4ff31 100644 --- a/drivers/vfio/device_cdev.c +++ b/drivers/vfio/device_cdev.c @@ -39,6 +39,13 @@ int vfio_device_fops_cdev_open(struct inode *inode, struct file *filep) filep->private_data = df; + /* + * Use the pseudo fs inode on the device to link all mmaps + * to the same address space, allowing us to unmap all vmas + * associated to this device using unmap_mapping_range(). + */ + filep->f_mapping = device->inode->i_mapping; + return 0; err_put_registration: diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c index 54c3079031e16..4cd857ff0259b 100644 --- a/drivers/vfio/group.c +++ b/drivers/vfio/group.c @@ -285,6 +285,13 @@ static struct file *vfio_device_open_file(struct vfio_device *device) */ filep->f_mode |= (FMODE_PREAD | FMODE_PWRITE); + /* + * Use the pseudo fs inode on the device to link all mmaps + * to the same address space, allowing us to unmap all vmas + * associated to this device using unmap_mapping_range(). + */ + filep->f_mapping = device->inode->i_mapping; + if (device->group->type == VFIO_NO_IOMMU) dev_warn(device->dev, "vfio-noiommu device opened by user " "(%s:%d)\n", current->comm, task_pid_nr(current)); diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index 6dfb290c339f9..ec4fbd993bf00 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -22,8 +22,10 @@ #include #include #include +#include #include #include +#include #include #include #include @@ -43,9 +45,13 @@ #define DRIVER_AUTHOR "Alex Williamson " #define DRIVER_DESC "VFIO - User Level meta-driver" +#define VFIO_MAGIC 0x5646494f /* "VFIO" */ + static struct vfio { struct class *device_class; struct ida device_ida; + struct vfsmount *vfs_mount; + int fs_count; } vfio; #ifdef CONFIG_VFIO_NOIOMMU @@ -186,6 +192,8 @@ static void vfio_device_release(struct device *dev) if (device->ops->release) device->ops->release(device); + iput(device->inode); + simple_release_fs(&vfio.vfs_mount, &vfio.fs_count); kvfree(device); } @@ -228,6 +236,34 @@ struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev, } EXPORT_SYMBOL_GPL(_vfio_alloc_device); +static int vfio_fs_init_fs_context(struct fs_context *fc) +{ + return init_pseudo(fc, VFIO_MAGIC) ? 0 : -ENOMEM; +} + +static struct file_system_type vfio_fs_type = { + .name = "vfio", + .owner = THIS_MODULE, + .init_fs_context = vfio_fs_init_fs_context, + .kill_sb = kill_anon_super, +}; + +static struct inode *vfio_fs_inode_new(void) +{ + struct inode *inode; + int ret; + + ret = simple_pin_fs(&vfio_fs_type, &vfio.vfs_mount, &vfio.fs_count); + if (ret) + return ERR_PTR(ret); + + inode = alloc_anon_inode(vfio.vfs_mount->mnt_sb); + if (IS_ERR(inode)) + simple_release_fs(&vfio.vfs_mount, &vfio.fs_count); + + return inode; +} + /* * Initialize a vfio_device so it can be registered to vfio core. */ @@ -246,6 +282,11 @@ static int vfio_init_device(struct vfio_device *device, struct device *dev, init_completion(&device->comp); device->dev = dev; device->ops = ops; + device->inode = vfio_fs_inode_new(); + if (IS_ERR(device->inode)) { + ret = PTR_ERR(device->inode); + goto out_inode; + } if (ops->init) { ret = ops->init(device); @@ -260,6 +301,9 @@ static int vfio_init_device(struct vfio_device *device, struct device *dev, return 0; out_uninit: + iput(device->inode); + simple_release_fs(&vfio.vfs_mount, &vfio.fs_count); +out_inode: vfio_release_device_set(device); ida_free(&vfio.device_ida, device->index); return ret; diff --git a/include/linux/vfio.h b/include/linux/vfio.h index 5ac5f182ce0bb..514a7f9b3ef4b 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -64,6 +64,7 @@ struct vfio_device { struct completion comp; struct iommufd_access *iommufd_access; void (*put_kvm)(struct kvm *kvm); + struct inode *inode; #if IS_ENABLED(CONFIG_IOMMUFD) struct iommufd_device *iommufd_device; u8 iommufd_attached:1; -- 2.53.0