diff options
Diffstat (limited to 'drivers/vfio/mdev')
| -rw-r--r-- | drivers/vfio/mdev/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/vfio/mdev/Makefile | 5 | ||||
| -rw-r--r-- | drivers/vfio/mdev/mdev_core.c | 275 | ||||
| -rw-r--r-- | drivers/vfio/mdev/mdev_driver.c | 75 | ||||
| -rw-r--r-- | drivers/vfio/mdev/mdev_private.h | 33 | ||||
| -rw-r--r-- | drivers/vfio/mdev/mdev_sysfs.c | 302 |
6 files changed, 700 insertions, 0 deletions
diff --git a/drivers/vfio/mdev/Kconfig b/drivers/vfio/mdev/Kconfig new file mode 100644 index 000000000..646dbed44 --- /dev/null +++ b/drivers/vfio/mdev/Kconfig @@ -0,0 +1,10 @@ +# SPDX-License-Identifier: GPL-2.0-only + +config VFIO_MDEV + tristate "Mediated device driver framework" + default n + help + Provides a framework to virtualize devices. + See Documentation/driver-api/vfio-mediated-device.rst for more details. + + If you don't know what do here, say N. diff --git a/drivers/vfio/mdev/Makefile b/drivers/vfio/mdev/Makefile new file mode 100644 index 000000000..7c236ba1b --- /dev/null +++ b/drivers/vfio/mdev/Makefile @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0-only + +mdev-y := mdev_core.o mdev_sysfs.o mdev_driver.o + +obj-$(CONFIG_VFIO_MDEV) += mdev.o diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c new file mode 100644 index 000000000..ed4737de4 --- /dev/null +++ b/drivers/vfio/mdev/mdev_core.c @@ -0,0 +1,275 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Mediated device Core Driver + * + * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved. + * Author: Neo Jia <cjia@nvidia.com> + * Kirti Wankhede <kwankhede@nvidia.com> + */ + +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/sysfs.h> +#include <linux/mdev.h> + +#include "mdev_private.h" + +#define DRIVER_VERSION "0.1" +#define DRIVER_AUTHOR "NVIDIA Corporation" +#define DRIVER_DESC "Mediated device Core Driver" + +static struct class_compat *mdev_bus_compat_class; + +static LIST_HEAD(mdev_list); +static DEFINE_MUTEX(mdev_list_lock); + +/* Caller must hold parent unreg_sem read or write lock */ +static void mdev_device_remove_common(struct mdev_device *mdev) +{ + struct mdev_parent *parent = mdev->type->parent; + + mdev_remove_sysfs_files(mdev); + device_del(&mdev->dev); + lockdep_assert_held(&parent->unreg_sem); + /* Balances with device_initialize() */ + put_device(&mdev->dev); +} + +static int mdev_device_remove_cb(struct device *dev, void *data) +{ + if (dev->bus == &mdev_bus_type) + mdev_device_remove_common(to_mdev_device(dev)); + return 0; +} + +/* + * mdev_register_parent: Register a device as parent for mdevs + * @parent: parent structure registered + * @dev: device structure representing parent device. + * @mdev_driver: Device driver to bind to the newly created mdev + * @types: Array of supported mdev types + * @nr_types: Number of entries in @types + * + * Registers the @parent stucture as a parent for mdev types and thus mdev + * devices. The caller needs to hold a reference on @dev that must not be + * released until after the call to mdev_unregister_parent(). + * + * Returns a negative value on error, otherwise 0. + */ +int mdev_register_parent(struct mdev_parent *parent, struct device *dev, + struct mdev_driver *mdev_driver, struct mdev_type **types, + unsigned int nr_types) +{ + char *env_string = "MDEV_STATE=registered"; + char *envp[] = { env_string, NULL }; + int ret; + + memset(parent, 0, sizeof(*parent)); + init_rwsem(&parent->unreg_sem); + parent->dev = dev; + parent->mdev_driver = mdev_driver; + parent->types = types; + parent->nr_types = nr_types; + atomic_set(&parent->available_instances, mdev_driver->max_instances); + + ret = parent_create_sysfs_files(parent); + if (ret) + return ret; + + ret = class_compat_create_link(mdev_bus_compat_class, dev, NULL); + if (ret) + dev_warn(dev, "Failed to create compatibility class link\n"); + + dev_info(dev, "MDEV: Registered\n"); + kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp); + return 0; +} +EXPORT_SYMBOL(mdev_register_parent); + +/* + * mdev_unregister_parent : Unregister a parent device + * @parent: parent structure to unregister + */ +void mdev_unregister_parent(struct mdev_parent *parent) +{ + char *env_string = "MDEV_STATE=unregistered"; + char *envp[] = { env_string, NULL }; + + dev_info(parent->dev, "MDEV: Unregistering\n"); + + down_write(&parent->unreg_sem); + class_compat_remove_link(mdev_bus_compat_class, parent->dev, NULL); + device_for_each_child(parent->dev, NULL, mdev_device_remove_cb); + parent_remove_sysfs_files(parent); + up_write(&parent->unreg_sem); + + kobject_uevent_env(&parent->dev->kobj, KOBJ_CHANGE, envp); +} +EXPORT_SYMBOL(mdev_unregister_parent); + +static void mdev_device_release(struct device *dev) +{ + struct mdev_device *mdev = to_mdev_device(dev); + struct mdev_parent *parent = mdev->type->parent; + + mutex_lock(&mdev_list_lock); + list_del(&mdev->next); + if (!parent->mdev_driver->get_available) + atomic_inc(&parent->available_instances); + mutex_unlock(&mdev_list_lock); + + /* Pairs with the get in mdev_device_create() */ + kobject_put(&mdev->type->kobj); + + dev_dbg(&mdev->dev, "MDEV: destroying\n"); + kfree(mdev); +} + +int mdev_device_create(struct mdev_type *type, const guid_t *uuid) +{ + int ret; + struct mdev_device *mdev, *tmp; + struct mdev_parent *parent = type->parent; + struct mdev_driver *drv = parent->mdev_driver; + + mutex_lock(&mdev_list_lock); + + /* Check for duplicate */ + list_for_each_entry(tmp, &mdev_list, next) { + if (guid_equal(&tmp->uuid, uuid)) { + mutex_unlock(&mdev_list_lock); + return -EEXIST; + } + } + + if (!drv->get_available) { + /* + * Note: that non-atomic read and dec is fine here because + * all modifications are under mdev_list_lock. + */ + if (!atomic_read(&parent->available_instances)) { + mutex_unlock(&mdev_list_lock); + return -EUSERS; + } + atomic_dec(&parent->available_instances); + } + + mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); + if (!mdev) { + mutex_unlock(&mdev_list_lock); + return -ENOMEM; + } + + device_initialize(&mdev->dev); + mdev->dev.parent = parent->dev; + mdev->dev.bus = &mdev_bus_type; + mdev->dev.release = mdev_device_release; + mdev->dev.groups = mdev_device_groups; + mdev->type = type; + /* Pairs with the put in mdev_device_release() */ + kobject_get(&type->kobj); + + guid_copy(&mdev->uuid, uuid); + list_add(&mdev->next, &mdev_list); + mutex_unlock(&mdev_list_lock); + + ret = dev_set_name(&mdev->dev, "%pUl", uuid); + if (ret) + goto out_put_device; + + /* Check if parent unregistration has started */ + if (!down_read_trylock(&parent->unreg_sem)) { + ret = -ENODEV; + goto out_put_device; + } + + ret = device_add(&mdev->dev); + if (ret) + goto out_unlock; + + ret = device_driver_attach(&drv->driver, &mdev->dev); + if (ret) + goto out_del; + + ret = mdev_create_sysfs_files(mdev); + if (ret) + goto out_del; + + mdev->active = true; + dev_dbg(&mdev->dev, "MDEV: created\n"); + up_read(&parent->unreg_sem); + + return 0; + +out_del: + device_del(&mdev->dev); +out_unlock: + up_read(&parent->unreg_sem); +out_put_device: + put_device(&mdev->dev); + return ret; +} + +int mdev_device_remove(struct mdev_device *mdev) +{ + struct mdev_device *tmp; + struct mdev_parent *parent = mdev->type->parent; + + mutex_lock(&mdev_list_lock); + list_for_each_entry(tmp, &mdev_list, next) { + if (tmp == mdev) + break; + } + + if (tmp != mdev) { + mutex_unlock(&mdev_list_lock); + return -ENODEV; + } + + if (!mdev->active) { + mutex_unlock(&mdev_list_lock); + return -EAGAIN; + } + + mdev->active = false; + mutex_unlock(&mdev_list_lock); + + /* Check if parent unregistration has started */ + if (!down_read_trylock(&parent->unreg_sem)) + return -ENODEV; + + mdev_device_remove_common(mdev); + up_read(&parent->unreg_sem); + return 0; +} + +static int __init mdev_init(void) +{ + int ret; + + ret = bus_register(&mdev_bus_type); + if (ret) + return ret; + + mdev_bus_compat_class = class_compat_register("mdev_bus"); + if (!mdev_bus_compat_class) { + bus_unregister(&mdev_bus_type); + return -ENOMEM; + } + + return 0; +} + +static void __exit mdev_exit(void) +{ + class_compat_unregister(mdev_bus_compat_class); + bus_unregister(&mdev_bus_type); +} + +subsys_initcall(mdev_init) +module_exit(mdev_exit) + +MODULE_VERSION(DRIVER_VERSION); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR(DRIVER_AUTHOR); +MODULE_DESCRIPTION(DRIVER_DESC); diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c new file mode 100644 index 000000000..7825d83a5 --- /dev/null +++ b/drivers/vfio/mdev/mdev_driver.c @@ -0,0 +1,75 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * MDEV driver + * + * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved. + * Author: Neo Jia <cjia@nvidia.com> + * Kirti Wankhede <kwankhede@nvidia.com> + */ + +#include <linux/iommu.h> +#include <linux/mdev.h> + +#include "mdev_private.h" + +static int mdev_probe(struct device *dev) +{ + struct mdev_driver *drv = + container_of(dev->driver, struct mdev_driver, driver); + + if (!drv->probe) + return 0; + return drv->probe(to_mdev_device(dev)); +} + +static void mdev_remove(struct device *dev) +{ + struct mdev_driver *drv = + container_of(dev->driver, struct mdev_driver, driver); + + if (drv->remove) + drv->remove(to_mdev_device(dev)); +} + +static int mdev_match(struct device *dev, struct device_driver *drv) +{ + /* + * No drivers automatically match. Drivers are only bound by explicit + * device_driver_attach() + */ + return 0; +} + +struct bus_type mdev_bus_type = { + .name = "mdev", + .probe = mdev_probe, + .remove = mdev_remove, + .match = mdev_match, +}; + +/** + * mdev_register_driver - register a new MDEV driver + * @drv: the driver to register + * + * Returns a negative value on error, otherwise 0. + **/ +int mdev_register_driver(struct mdev_driver *drv) +{ + if (!drv->device_api) + return -EINVAL; + + /* initialize common driver fields */ + drv->driver.bus = &mdev_bus_type; + return driver_register(&drv->driver); +} +EXPORT_SYMBOL(mdev_register_driver); + +/* + * mdev_unregister_driver - unregister MDEV driver + * @drv: the driver to unregister + */ +void mdev_unregister_driver(struct mdev_driver *drv) +{ + driver_unregister(&drv->driver); +} +EXPORT_SYMBOL(mdev_unregister_driver); diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h new file mode 100644 index 000000000..af457b27f --- /dev/null +++ b/drivers/vfio/mdev/mdev_private.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Mediated device internal definitions + * + * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved. + * Author: Neo Jia <cjia@nvidia.com> + * Kirti Wankhede <kwankhede@nvidia.com> + */ + +#ifndef MDEV_PRIVATE_H +#define MDEV_PRIVATE_H + +int mdev_bus_register(void); +void mdev_bus_unregister(void); + +extern struct bus_type mdev_bus_type; +extern const struct attribute_group *mdev_device_groups[]; + +#define to_mdev_type_attr(_attr) \ + container_of(_attr, struct mdev_type_attribute, attr) +#define to_mdev_type(_kobj) \ + container_of(_kobj, struct mdev_type, kobj) + +int parent_create_sysfs_files(struct mdev_parent *parent); +void parent_remove_sysfs_files(struct mdev_parent *parent); + +int mdev_create_sysfs_files(struct mdev_device *mdev); +void mdev_remove_sysfs_files(struct mdev_device *mdev); + +int mdev_device_create(struct mdev_type *kobj, const guid_t *uuid); +int mdev_device_remove(struct mdev_device *dev); + +#endif /* MDEV_PRIVATE_H */ diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c new file mode 100644 index 000000000..16b007c6b --- /dev/null +++ b/drivers/vfio/mdev/mdev_sysfs.c @@ -0,0 +1,302 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * File attributes for Mediated devices + * + * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved. + * Author: Neo Jia <cjia@nvidia.com> + * Kirti Wankhede <kwankhede@nvidia.com> + */ + +#include <linux/sysfs.h> +#include <linux/ctype.h> +#include <linux/slab.h> +#include <linux/mdev.h> + +#include "mdev_private.h" + +struct mdev_type_attribute { + struct attribute attr; + ssize_t (*show)(struct mdev_type *mtype, + struct mdev_type_attribute *attr, char *buf); + ssize_t (*store)(struct mdev_type *mtype, + struct mdev_type_attribute *attr, const char *buf, + size_t count); +}; + +#define MDEV_TYPE_ATTR_RO(_name) \ + struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RO(_name) +#define MDEV_TYPE_ATTR_WO(_name) \ + struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_WO(_name) + +static ssize_t mdev_type_attr_show(struct kobject *kobj, + struct attribute *__attr, char *buf) +{ + struct mdev_type_attribute *attr = to_mdev_type_attr(__attr); + struct mdev_type *type = to_mdev_type(kobj); + ssize_t ret = -EIO; + + if (attr->show) + ret = attr->show(type, attr, buf); + return ret; +} + +static ssize_t mdev_type_attr_store(struct kobject *kobj, + struct attribute *__attr, + const char *buf, size_t count) +{ + struct mdev_type_attribute *attr = to_mdev_type_attr(__attr); + struct mdev_type *type = to_mdev_type(kobj); + ssize_t ret = -EIO; + + if (attr->store) + ret = attr->store(type, attr, buf, count); + return ret; +} + +static const struct sysfs_ops mdev_type_sysfs_ops = { + .show = mdev_type_attr_show, + .store = mdev_type_attr_store, +}; + +static ssize_t create_store(struct mdev_type *mtype, + struct mdev_type_attribute *attr, const char *buf, + size_t count) +{ + char *str; + guid_t uuid; + int ret; + + if ((count < UUID_STRING_LEN) || (count > UUID_STRING_LEN + 1)) + return -EINVAL; + + str = kstrndup(buf, count, GFP_KERNEL); + if (!str) + return -ENOMEM; + + ret = guid_parse(str, &uuid); + kfree(str); + if (ret) + return ret; + + ret = mdev_device_create(mtype, &uuid); + if (ret) + return ret; + + return count; +} +static MDEV_TYPE_ATTR_WO(create); + +static ssize_t device_api_show(struct mdev_type *mtype, + struct mdev_type_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%s\n", mtype->parent->mdev_driver->device_api); +} +static MDEV_TYPE_ATTR_RO(device_api); + +static ssize_t name_show(struct mdev_type *mtype, + struct mdev_type_attribute *attr, char *buf) +{ + return sprintf(buf, "%s\n", + mtype->pretty_name ? mtype->pretty_name : mtype->sysfs_name); +} + +static MDEV_TYPE_ATTR_RO(name); + +static ssize_t available_instances_show(struct mdev_type *mtype, + struct mdev_type_attribute *attr, + char *buf) +{ + struct mdev_driver *drv = mtype->parent->mdev_driver; + + if (drv->get_available) + return sysfs_emit(buf, "%u\n", drv->get_available(mtype)); + return sysfs_emit(buf, "%u\n", + atomic_read(&mtype->parent->available_instances)); +} +static MDEV_TYPE_ATTR_RO(available_instances); + +static ssize_t description_show(struct mdev_type *mtype, + struct mdev_type_attribute *attr, + char *buf) +{ + return mtype->parent->mdev_driver->show_description(mtype, buf); +} +static MDEV_TYPE_ATTR_RO(description); + +static struct attribute *mdev_types_core_attrs[] = { + &mdev_type_attr_create.attr, + &mdev_type_attr_device_api.attr, + &mdev_type_attr_name.attr, + &mdev_type_attr_available_instances.attr, + &mdev_type_attr_description.attr, + NULL, +}; + +static umode_t mdev_types_core_is_visible(struct kobject *kobj, + struct attribute *attr, int n) +{ + if (attr == &mdev_type_attr_description.attr && + !to_mdev_type(kobj)->parent->mdev_driver->show_description) + return 0; + return attr->mode; +} + +static struct attribute_group mdev_type_core_group = { + .attrs = mdev_types_core_attrs, + .is_visible = mdev_types_core_is_visible, +}; + +static const struct attribute_group *mdev_type_groups[] = { + &mdev_type_core_group, + NULL, +}; + +static void mdev_type_release(struct kobject *kobj) +{ + struct mdev_type *type = to_mdev_type(kobj); + + pr_debug("Releasing group %s\n", kobj->name); + /* Pairs with the get in add_mdev_supported_type() */ + put_device(type->parent->dev); +} + +static struct kobj_type mdev_type_ktype = { + .sysfs_ops = &mdev_type_sysfs_ops, + .release = mdev_type_release, + .default_groups = mdev_type_groups, +}; + +static int mdev_type_add(struct mdev_parent *parent, struct mdev_type *type) +{ + int ret; + + type->kobj.kset = parent->mdev_types_kset; + type->parent = parent; + /* Pairs with the put in mdev_type_release() */ + get_device(parent->dev); + + ret = kobject_init_and_add(&type->kobj, &mdev_type_ktype, NULL, + "%s-%s", dev_driver_string(parent->dev), + type->sysfs_name); + if (ret) { + kobject_put(&type->kobj); + return ret; + } + + type->devices_kobj = kobject_create_and_add("devices", &type->kobj); + if (!type->devices_kobj) { + ret = -ENOMEM; + goto attr_devices_failed; + } + + return 0; + +attr_devices_failed: + kobject_del(&type->kobj); + kobject_put(&type->kobj); + return ret; +} + +static void mdev_type_remove(struct mdev_type *type) +{ + kobject_put(type->devices_kobj); + kobject_del(&type->kobj); + kobject_put(&type->kobj); +} + +/* mdev sysfs functions */ +void parent_remove_sysfs_files(struct mdev_parent *parent) +{ + int i; + + for (i = 0; i < parent->nr_types; i++) + mdev_type_remove(parent->types[i]); + kset_unregister(parent->mdev_types_kset); +} + +int parent_create_sysfs_files(struct mdev_parent *parent) +{ + int ret, i; + + parent->mdev_types_kset = kset_create_and_add("mdev_supported_types", + NULL, &parent->dev->kobj); + if (!parent->mdev_types_kset) + return -ENOMEM; + + for (i = 0; i < parent->nr_types; i++) { + ret = mdev_type_add(parent, parent->types[i]); + if (ret) + goto out_err; + } + return 0; + +out_err: + while (--i >= 0) + mdev_type_remove(parent->types[i]); + kset_unregister(parent->mdev_types_kset); + return ret; +} + +static ssize_t remove_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct mdev_device *mdev = to_mdev_device(dev); + unsigned long val; + + if (kstrtoul(buf, 0, &val) < 0) + return -EINVAL; + + if (val && device_remove_file_self(dev, attr)) { + int ret; + + ret = mdev_device_remove(mdev); + if (ret) + return ret; + } + + return count; +} + +static DEVICE_ATTR_WO(remove); + +static struct attribute *mdev_device_attrs[] = { + &dev_attr_remove.attr, + NULL, +}; + +static const struct attribute_group mdev_device_group = { + .attrs = mdev_device_attrs, +}; + +const struct attribute_group *mdev_device_groups[] = { + &mdev_device_group, + NULL +}; + +int mdev_create_sysfs_files(struct mdev_device *mdev) +{ + struct mdev_type *type = mdev->type; + struct kobject *kobj = &mdev->dev.kobj; + int ret; + + ret = sysfs_create_link(type->devices_kobj, kobj, dev_name(&mdev->dev)); + if (ret) + return ret; + + ret = sysfs_create_link(kobj, &type->kobj, "mdev_type"); + if (ret) + goto type_link_failed; + return ret; + +type_link_failed: + sysfs_remove_link(mdev->type->devices_kobj, dev_name(&mdev->dev)); + return ret; +} + +void mdev_remove_sysfs_files(struct mdev_device *mdev) +{ + struct kobject *kobj = &mdev->dev.kobj; + + sysfs_remove_link(kobj, "mdev_type"); + sysfs_remove_link(mdev->type->devices_kobj, dev_name(&mdev->dev)); +} |