diff --git a/Documentation/ABI/testing/sysfs-devices-vfio-dev b/Documentation/ABI/testing/sysfs-devices-vfio-dev new file mode 100644 index 000000000000..e21424fd9666 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-vfio-dev @@ -0,0 +1,8 @@ +What: /sys/...//vfio-dev/vfioX/ +Date: September 2022 +Contact: Yi Liu +Description: + This directory is created when the device is bound to a + vfio driver. The layout under this directory matches what + exists for a standard 'struct device'. 'X' is a unique + index marking this device in vfio. diff --git a/MAINTAINERS b/MAINTAINERS index d30f26e07cd3..02c8f11b1c17 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -21312,6 +21312,7 @@ R: Cornelia Huck L: kvm@vger.kernel.org S: Maintained T: git git://github.com/awilliam/linux-vfio.git +F: Documentation/ABI/testing/sysfs-devices-vfio-dev F: Documentation/driver-api/vfio.rst F: drivers/vfio/ F: include/linux/vfio.h diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index c27449613a1d..f9d10dbcf3e6 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -49,6 +49,8 @@ static struct vfio { struct mutex group_lock; /* locks group_list */ struct ida group_ida; dev_t group_devt; + struct class *device_class; + struct ida device_ida; } vfio; struct vfio_iommu_driver { @@ -485,12 +487,13 @@ static struct vfio_device *vfio_group_get_device(struct vfio_group *group, * VFIO driver API */ /* Release helper called by vfio_put_device() */ -void vfio_device_release(struct kref *kref) +static void vfio_device_release(struct device *dev) { struct vfio_device *device = - container_of(kref, struct vfio_device, kref); + container_of(dev, struct vfio_device, device); vfio_release_device_set(device); + ida_free(&vfio.device_ida, device->index); /* * kvfree() cannot be done here due to a life cycle mess in @@ -500,7 +503,6 @@ void vfio_device_release(struct kref *kref) */ device->ops->release(device); } -EXPORT_SYMBOL_GPL(vfio_device_release); /* * Allocate and initialize vfio_device so it can be registered to vfio @@ -548,6 +550,13 @@ int vfio_init_device(struct vfio_device *device, struct device *dev, { int ret; + ret = ida_alloc_max(&vfio.device_ida, MINORMASK, GFP_KERNEL); + if (ret < 0) { + dev_dbg(dev, "Error to alloc index\n"); + return ret; + } + + device->index = ret; init_completion(&device->comp); device->dev = dev; device->ops = ops; @@ -558,11 +567,15 @@ int vfio_init_device(struct vfio_device *device, struct device *dev, goto out_uninit; } - kref_init(&device->kref); + device_initialize(&device->device); + device->device.release = vfio_device_release; + device->device.class = vfio.device_class; + device->device.parent = device->dev; return 0; out_uninit: vfio_release_device_set(device); + ida_free(&vfio.device_ida, device->index); return ret; } EXPORT_SYMBOL_GPL(vfio_init_device); @@ -659,6 +672,7 @@ static int __vfio_register_dev(struct vfio_device *device, struct vfio_group *group) { struct vfio_device *existing_device; + int ret; if (IS_ERR(group)) return PTR_ERR(group); @@ -675,16 +689,21 @@ static int __vfio_register_dev(struct vfio_device *device, dev_WARN(device->dev, "Device already exists on group %d\n", iommu_group_id(group->iommu_group)); vfio_device_put_registration(existing_device); - if (group->type == VFIO_NO_IOMMU || - group->type == VFIO_EMULATED_IOMMU) - iommu_group_remove_device(device->dev); - vfio_group_put(group); - return -EBUSY; + ret = -EBUSY; + goto err_out; } /* Our reference on group is moved to the device */ device->group = group; + ret = dev_set_name(&device->device, "vfio%d", device->index); + if (ret) + goto err_out; + + ret = device_add(&device->device); + if (ret) + goto err_out; + /* Refcounting can't start until the driver calls register */ refcount_set(&device->refcount, 1); @@ -693,6 +712,12 @@ static int __vfio_register_dev(struct vfio_device *device, mutex_unlock(&group->device_lock); return 0; +err_out: + if (group->type == VFIO_NO_IOMMU || + group->type == VFIO_EMULATED_IOMMU) + iommu_group_remove_device(device->dev); + vfio_group_put(group); + return ret; } int vfio_register_group_dev(struct vfio_device *device) @@ -779,6 +804,9 @@ void vfio_unregister_group_dev(struct vfio_device *device) list_del(&device->group_next); mutex_unlock(&group->device_lock); + /* Balances device_add in register path */ + device_del(&device->device); + if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU) iommu_group_remove_device(device->dev); @@ -2362,6 +2390,7 @@ static int __init vfio_init(void) int ret; ida_init(&vfio.group_ida); + ida_init(&vfio.device_ida); mutex_init(&vfio.group_lock); mutex_init(&vfio.iommu_drivers_lock); INIT_LIST_HEAD(&vfio.group_list); @@ -2377,11 +2406,18 @@ static int __init vfio_init(void) vfio.class = class_create(THIS_MODULE, "vfio"); if (IS_ERR(vfio.class)) { ret = PTR_ERR(vfio.class); - goto err_class; + goto err_group_class; } vfio.class->devnode = vfio_devnode; + /* /sys/class/vfio-dev/vfioX */ + vfio.device_class = class_create(THIS_MODULE, "vfio-dev"); + if (IS_ERR(vfio.device_class)) { + ret = PTR_ERR(vfio.device_class); + goto err_dev_class; + } + ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio"); if (ret) goto err_alloc_chrdev; @@ -2398,9 +2434,12 @@ static int __init vfio_init(void) err_driver_register: unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); err_alloc_chrdev: + class_destroy(vfio.device_class); + vfio.device_class = NULL; +err_dev_class: class_destroy(vfio.class); vfio.class = NULL; -err_class: +err_group_class: misc_deregister(&vfio_dev); return ret; } @@ -2412,8 +2451,11 @@ static void __exit vfio_cleanup(void) #ifdef CONFIG_VFIO_NOIOMMU vfio_unregister_iommu_driver(&vfio_noiommu_ops); #endif + ida_destroy(&vfio.device_ida); ida_destroy(&vfio.group_ida); unregister_chrdev_region(vfio.group_devt, MINORMASK + 1); + class_destroy(vfio.device_class); + vfio.device_class = NULL; class_destroy(vfio.class); vfio.class = NULL; misc_deregister(&vfio_dev); diff --git a/include/linux/vfio.h b/include/linux/vfio.h index 3cf857b1eec7..ee399a768070 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -47,7 +47,8 @@ struct vfio_device { struct kvm *kvm; /* Members below here are private, not for driver use */ - struct kref kref; /* object life cycle */ + unsigned int index; + struct device device; /* device.kref covers object life circle */ refcount_t refcount; /* user count on registered device*/ unsigned int open_count; struct completion comp; @@ -178,10 +179,9 @@ struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev, int vfio_init_device(struct vfio_device *device, struct device *dev, const struct vfio_device_ops *ops); void vfio_free_device(struct vfio_device *device); -void vfio_device_release(struct kref *kref); static inline void vfio_put_device(struct vfio_device *device) { - kref_put(&device->kref, vfio_device_release); + put_device(&device->device); } int vfio_register_group_dev(struct vfio_device *device);