From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: Re: [PATCH 1/3] Mediated device Core driver Date: Wed, 29 Jun 2016 21:51:06 +0800 Message-ID: <5773D24A.4060005@linux.intel.com> References: <1466440308-4961-1-git-send-email-kwankhede@nvidia.com> <1466440308-4961-2-git-send-email-kwankhede@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: shuai.ruan@intel.com, jike.song@intel.com, kvm@vger.kernel.org, kevin.tian@intel.com, qemu-devel@nongnu.org, zhiyuan.lv@intel.com, bjsdjshi@linux.vnet.ibm.com To: Kirti Wankhede , alex.williamson@redhat.com, pbonzini@redhat.com, kraxel@redhat.com, cjia@nvidia.com Return-path: In-Reply-To: <1466440308-4961-2-git-send-email-kwankhede@nvidia.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: "Qemu-devel" List-Id: kvm.vger.kernel.org On 06/21/2016 12:31 AM, Kirti Wankhede wrote: > Design for Mediated Device Driver: > Main purpose of this driver is to provide a common interface for mediated > device management that can be used by differnt drivers of different > devices. > > This module provides a generic interface to create the device, add it to > mediated bus, add device to IOMMU group and then add it to vfio group. > > Below is the high Level block diagram, with Nvidia, Intel and IBM devices > as example, since these are the devices which are going to actively use > this module as of now. > > +---------------+ > | | > | +-----------+ | mdev_register_driver() +--------------+ > | | | +<------------------------+ __init() | > | | | | | | > | | mdev | +------------------------>+ |<-> VFIO user > | | bus | | probe()/remove() | vfio_mpci.ko | APIs > | | driver | | | | > | | | | +--------------+ > | | | | mdev_register_driver() +--------------+ > | | | +<------------------------+ __init() | > | | | | | | > | | | +------------------------>+ |<-> VFIO user > | +-----------+ | probe()/remove() | vfio_mccw.ko | APIs > | | | | > | MDEV CORE | +--------------+ > | MODULE | > | mdev.ko | > | +-----------+ | mdev_register_device() +--------------+ > | | | +<------------------------+ | > | | | | | nvidia.ko |<-> physical > | | | +------------------------>+ | device > | | | | callback +--------------+ > | | Physical | | > | | device | | mdev_register_device() +--------------+ > | | interface | |<------------------------+ | > | | | | | i915.ko |<-> physical > | | | +------------------------>+ | device > | | | | callback +--------------+ > | | | | > | | | | mdev_register_device() +--------------+ > | | | +<------------------------+ | > | | | | | ccw_device.ko|<-> physical > | | | +------------------------>+ | device > | | | | callback +--------------+ > | +-----------+ | > +---------------+ > > Core driver provides two types of registration interfaces: > 1. Registration interface for mediated bus driver: > > /** > * struct mdev_driver - Mediated device's driver > * @name: driver name > * @probe: called when new device created > * @remove:called when device removed > * @match: called when new device or driver is added for this bus. > Return 1 if given device can be handled by given driver and > zero otherwise. > * @driver:device driver structure > * > **/ > struct mdev_driver { > const char *name; > int (*probe) (struct device *dev); > void (*remove) (struct device *dev); > int (*match)(struct device *dev); > struct device_driver driver; > }; > > int mdev_register_driver(struct mdev_driver *drv, struct module *owner); > void mdev_unregister_driver(struct mdev_driver *drv); > > Mediated device's driver for mdev should use this interface to register > with Core driver. With this, mediated devices driver for such devices is > responsible to add mediated device to VFIO group. > > 2. Physical device driver interface > This interface provides vendor driver the set APIs to manage physical > device related work in their own driver. APIs are : > - supported_config: provide supported configuration list by the vendor > driver > - create: to allocate basic resources in vendor driver for a mediated > device. > - destroy: to free resources in vendor driver when mediated device is > destroyed. > - start: to initiate mediated device initialization process from vendor > driver when VM boots and before QEMU starts. > - shutdown: to teardown mediated device resources during VM teardown. > - read : read emulation callback. > - write: write emulation callback. > - set_irqs: send interrupt configuration information that QEMU sets. > - get_region_info: to provide region size and its flags for the mediated > device. > - validate_map_request: to validate remap pfn request. > > This registration interface should be used by vendor drivers to register > each physical device to mdev core driver. > > Signed-off-by: Kirti Wankhede > Signed-off-by: Neo Jia > Change-Id: I73a5084574270b14541c529461ea2f03c292d510 > --- > drivers/vfio/Kconfig | 1 + > drivers/vfio/Makefile | 1 + > drivers/vfio/mdev/Kconfig | 11 + > drivers/vfio/mdev/Makefile | 5 + > drivers/vfio/mdev/mdev_core.c | 595 +++++++++++++++++++++++++++++++++++++++ > drivers/vfio/mdev/mdev_driver.c | 138 +++++++++ > drivers/vfio/mdev/mdev_private.h | 33 +++ > drivers/vfio/mdev/mdev_sysfs.c | 300 ++++++++++++++++++++ > include/linux/mdev.h | 232 +++++++++++++++ > 9 files changed, 1316 insertions(+) > create mode 100644 drivers/vfio/mdev/Kconfig > create mode 100644 drivers/vfio/mdev/Makefile > create mode 100644 drivers/vfio/mdev/mdev_core.c > create mode 100644 drivers/vfio/mdev/mdev_driver.c > create mode 100644 drivers/vfio/mdev/mdev_private.h > create mode 100644 drivers/vfio/mdev/mdev_sysfs.c > create mode 100644 include/linux/mdev.h > > diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig > index da6e2ce77495..23eced02aaf6 100644 > --- a/drivers/vfio/Kconfig > +++ b/drivers/vfio/Kconfig > @@ -48,4 +48,5 @@ menuconfig VFIO_NOIOMMU > > source "drivers/vfio/pci/Kconfig" > source "drivers/vfio/platform/Kconfig" > +source "drivers/vfio/mdev/Kconfig" > source "virt/lib/Kconfig" > diff --git a/drivers/vfio/Makefile b/drivers/vfio/Makefile > index 7b8a31f63fea..7c70753e54ab 100644 > --- a/drivers/vfio/Makefile > +++ b/drivers/vfio/Makefile > @@ -7,3 +7,4 @@ obj-$(CONFIG_VFIO_IOMMU_SPAPR_TCE) += vfio_iommu_spapr_tce.o > obj-$(CONFIG_VFIO_SPAPR_EEH) += vfio_spapr_eeh.o > obj-$(CONFIG_VFIO_PCI) += pci/ > obj-$(CONFIG_VFIO_PLATFORM) += platform/ > +obj-$(CONFIG_MDEV) += mdev/ > diff --git a/drivers/vfio/mdev/Kconfig b/drivers/vfio/mdev/Kconfig > new file mode 100644 > index 000000000000..951e2bb06a3f > --- /dev/null > +++ b/drivers/vfio/mdev/Kconfig > @@ -0,0 +1,11 @@ > + > +config MDEV > + tristate "Mediated device driver framework" > + depends on VFIO > + default n > + help > + MDEV provides a framework to virtualize device without SR-IOV cap > + See Documentation/mdev.txt for more details. > + > + If you don't know what do here, say N. > + > diff --git a/drivers/vfio/mdev/Makefile b/drivers/vfio/mdev/Makefile > new file mode 100644 > index 000000000000..2c6d11f7bc24 > --- /dev/null > +++ b/drivers/vfio/mdev/Makefile > @@ -0,0 +1,5 @@ > + > +mdev-y := mdev_core.o mdev_sysfs.o mdev_driver.o > + > +obj-$(CONFIG_MDEV) += mdev.o > + > diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c > new file mode 100644 > index 000000000000..3c45ed2ae1e9 > --- /dev/null > +++ b/drivers/vfio/mdev/mdev_core.c > @@ -0,0 +1,595 @@ > +/* > + * Mediated device Core Driver > + * > + * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved. > + * Author: Neo Jia > + * Kirti Wankhede > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "mdev_private.h" > + > +#define DRIVER_VERSION "0.1" > +#define DRIVER_AUTHOR "NVIDIA Corporation" > +#define DRIVER_DESC "Mediated device Core Driver" > + > +#define MDEV_CLASS_NAME "mdev" > + > +static struct devices_list { > + struct list_head dev_list; > + struct mutex list_lock; > +} parent_devices; > + > +static int mdev_add_attribute_group(struct device *dev, > + const struct attribute_group **groups) > +{ > + return sysfs_create_groups(&dev->kobj, groups); > +} > + > +static void mdev_remove_attribute_group(struct device *dev, > + const struct attribute_group **groups) > +{ > + sysfs_remove_groups(&dev->kobj, groups); > +} > + better use device_add_groups() / device_remove_groups() instead? > +static struct mdev_device *find_mdev_device(struct parent_device *parent, > + uuid_le uuid, int instance) > +{ > + struct mdev_device *mdev = NULL, *p; > + > + list_for_each_entry(p, &parent->mdev_list, next) { > + if ((uuid_le_cmp(p->uuid, uuid) == 0) && > + (p->instance == instance)) { > + mdev = p; > + break; > + } > + } > + return mdev; > +} > + > +/* Should be called holding parent_devices.list_lock */ > +static struct parent_device *find_parent_device(struct device *dev) > +{ > + struct parent_device *parent = NULL, *p; > + > + WARN_ON(!mutex_is_locked(&parent_devices.list_lock)); This is a static function, do we really need this assert? > + list_for_each_entry(p, &parent_devices.dev_list, next) { > + if (p->dev == dev) { > + parent = p; > + break; > + } > + } > + return parent; > +} > + > +static void mdev_release_parent(struct kref *kref) > +{ > + struct parent_device *parent = container_of(kref, struct parent_device, > + ref); > + kfree(parent); > +} > + > +static > +inline struct parent_device *mdev_get_parent(struct parent_device *parent) > +{ > + if (parent) > + kref_get(&parent->ref); > + > + return parent; > +} > + > +static inline void mdev_put_parent(struct parent_device *parent) > +{ > + if (parent) > + kref_put(&parent->ref, mdev_release_parent); > +} > + > +static struct parent_device *mdev_get_parent_by_dev(struct device *dev) > +{ > + struct parent_device *parent = NULL, *p; > + > + mutex_lock(&parent_devices.list_lock); > + list_for_each_entry(p, &parent_devices.dev_list, next) { > + if (p->dev == dev) { > + parent = mdev_get_parent(p); > + break; > + } > + } Can directly call find_parent_device(). > + mutex_unlock(&parent_devices.list_lock); > + return parent; > +} > + > +static int mdev_device_create_ops(struct mdev_device *mdev, char *mdev_params) > +{ > + struct parent_device *parent = mdev->parent; > + int ret; > + > + mutex_lock(&parent->ops_lock); > + if (parent->ops->create) { > + ret = parent->ops->create(mdev->dev.parent, mdev->uuid, > + mdev->instance, mdev_params); I think it is better if we pass @mdev to this callback, then the parent driver can do its specified operations and associate it with the instance, e.g, via mdev->private. > + if (ret) > + goto create_ops_err; > + } > + > + ret = mdev_add_attribute_group(&mdev->dev, > + parent->ops->mdev_attr_groups); > +create_ops_err: > + mutex_unlock(&parent->ops_lock); > + return ret; > +} > + > +static int mdev_device_destroy_ops(struct mdev_device *mdev, bool force) > +{ > + struct parent_device *parent = mdev->parent; > + int ret = 0; > + > + /* > + * If vendor driver doesn't return success that means vendor > + * driver doesn't support hot-unplug > + */ > + mutex_lock(&parent->ops_lock); > + if (parent->ops->destroy) { > + ret = parent->ops->destroy(parent->dev, mdev->uuid, > + mdev->instance); > + if (ret && !force) { > + ret = -EBUSY; > + goto destroy_ops_err; > + } > + } > + mdev_remove_attribute_group(&mdev->dev, > + parent->ops->mdev_attr_groups); > +destroy_ops_err: > + mutex_unlock(&parent->ops_lock); > + > + return ret; > +} > + > +static void mdev_release_device(struct kref *kref) > +{ > + struct mdev_device *mdev = container_of(kref, struct mdev_device, ref); > + struct parent_device *parent = mdev->parent; > + > + device_unregister(&mdev->dev); > + wake_up(&parent->release_done); > + mdev_put_parent(parent); > +} > + > +struct mdev_device *mdev_get_device(struct mdev_device *mdev) > +{ > + if (mdev) > + kref_get(&mdev->ref); > + > + return mdev; > +} > +EXPORT_SYMBOL(mdev_get_device); > + > +void mdev_put_device(struct mdev_device *mdev) > +{ > + if (mdev) > + kref_put(&mdev->ref, mdev_release_device); > +} > +EXPORT_SYMBOL(mdev_put_device); > + > +/* > + * Find first mediated device from given uuid and increment refcount of > + * mediated device. Caller should call mdev_put_device() when the use of > + * mdev_device is done. > + */ > +static struct mdev_device *mdev_get_first_device_by_uuid(uuid_le uuid) > +{ > + struct mdev_device *mdev = NULL, *p; > + struct parent_device *parent; > + > + mutex_lock(&parent_devices.list_lock); > + list_for_each_entry(parent, &parent_devices.dev_list, next) { > + mutex_lock(&parent->mdev_list_lock); > + list_for_each_entry(p, &parent->mdev_list, next) { > + if (uuid_le_cmp(p->uuid, uuid) == 0) { > + mdev = mdev_get_device(p); > + break; > + } > + } > + mutex_unlock(&parent->mdev_list_lock); > + > + if (mdev) > + break; > + } > + mutex_unlock(&parent_devices.list_lock); > + return mdev; > +} > + > +/* > + * Find mediated device from given iommu_group and increment refcount of > + * mediated device. Caller should call mdev_put_device() when the use of > + * mdev_device is done. > + */ > +struct mdev_device *mdev_get_device_by_group(struct iommu_group *group) > +{ > + struct mdev_device *mdev = NULL, *p; > + struct parent_device *parent; > + > + mutex_lock(&parent_devices.list_lock); > + list_for_each_entry(parent, &parent_devices.dev_list, next) { > + mutex_lock(&parent->mdev_list_lock); > + list_for_each_entry(p, &parent->mdev_list, next) { > + if (!p->group) > + continue; > + > + if (iommu_group_id(p->group) == iommu_group_id(group)) { > + mdev = mdev_get_device(p); > + break; > + } > + } > + mutex_unlock(&parent->mdev_list_lock); > + > + if (mdev) > + break; > + } > + mutex_unlock(&parent_devices.list_lock); > + return mdev; > +} > +EXPORT_SYMBOL(mdev_get_device_by_group); > + > +/* > + * mdev_register_device : Register a device > + * @dev: device structure representing parent device. > + * @ops: Parent device operation structure to be registered. > + * > + * Add device to list of registered parent devices. > + * Returns a negative value on error, otherwise 0. > + */ > +int mdev_register_device(struct device *dev, const struct parent_ops *ops) > +{ > + int ret = 0; > + struct parent_device *parent; > + > + if (!dev || !ops) > + return -EINVAL; > + > + mutex_lock(&parent_devices.list_lock); > + > + /* Check for duplicate */ > + parent = find_parent_device(dev); > + if (parent) { > + ret = -EEXIST; > + goto add_dev_err; > + } > + > + parent = kzalloc(sizeof(*parent), GFP_KERNEL); > + if (!parent) { > + ret = -ENOMEM; > + goto add_dev_err; > + } > + > + kref_init(&parent->ref); > + list_add(&parent->next, &parent_devices.dev_list); > + mutex_unlock(&parent_devices.list_lock); It is not safe as Alex's already pointed it out. > + > + parent->dev = dev; > + parent->ops = ops; > + mutex_init(&parent->ops_lock); > + mutex_init(&parent->mdev_list_lock); > + INIT_LIST_HEAD(&parent->mdev_list); > + init_waitqueue_head(&parent->release_done); And no lock to protect these operations. > + > + ret = mdev_create_sysfs_files(dev); > + if (ret) > + goto add_sysfs_error; > + > + ret = mdev_add_attribute_group(dev, ops->dev_attr_groups); > + if (ret) > + goto add_group_error; > + > + dev_info(dev, "MDEV: Registered\n"); > + return 0; > + > +add_group_error: > + mdev_remove_sysfs_files(dev); > +add_sysfs_error: > + mutex_lock(&parent_devices.list_lock); > + list_del(&parent->next); > + mutex_unlock(&parent_devices.list_lock); > + mdev_put_parent(parent); > + return ret; > + > +add_dev_err: > + mutex_unlock(&parent_devices.list_lock); > + return ret; > +} > +EXPORT_SYMBOL(mdev_register_device); > + > +/* > + * mdev_unregister_device : Unregister a parent device > + * @dev: device structure representing parent device. > + * > + * Remove device from list of registered parent devices. Give a chance to free > + * existing mediated devices for given device. > + */ > + > +void mdev_unregister_device(struct device *dev) > +{ > + struct parent_device *parent; > + struct mdev_device *mdev, *n; > + int ret; > + > + mutex_lock(&parent_devices.list_lock); > + parent = find_parent_device(dev); > + > + if (!parent) { > + mutex_unlock(&parent_devices.list_lock); > + return; > + } > + dev_info(dev, "MDEV: Unregistering\n"); > + > + /* > + * Remove parent from the list and remove create and destroy sysfs > + * files so that no new mediated device could be created for this parent > + */ > + list_del(&parent->next); > + mdev_remove_sysfs_files(dev); > + mutex_unlock(&parent_devices.list_lock); > + find_parent_device() does not increase the refcount of the parent-device, after releasing the lock, is it still safe to use the device? > + mutex_lock(&parent->ops_lock); > + mdev_remove_attribute_group(dev, > + parent->ops->dev_attr_groups); Why mdev_remove_sysfs_files() and mdev_remove_attribute_group() are protected by different locks? > + mutex_unlock(&parent->ops_lock); > + > + mutex_lock(&parent->mdev_list_lock); > + list_for_each_entry_safe(mdev, n, &parent->mdev_list, next) { > + mdev_device_destroy_ops(mdev, true); > + list_del(&mdev->next); > + mdev_put_device(mdev); > + } > + mutex_unlock(&parent->mdev_list_lock); > + > + do { > + ret = wait_event_interruptible_timeout(parent->release_done, > + list_empty(&parent->mdev_list), HZ * 10); > + if (ret == -ERESTARTSYS) { > + dev_warn(dev, "Mediated devices are in use, task" > + " \"%s\" (%d) " > + "blocked until all are released", > + current->comm, task_pid_nr(current)); > + } > + } while (ret <= 0); > + > + mdev_put_parent(parent); > +} > +EXPORT_SYMBOL(mdev_unregister_device); > + > +/* > + * Functions required for mdev-sysfs > + */ > +static void mdev_device_release(struct device *dev) > +{ > + struct mdev_device *mdev = to_mdev_device(dev); > + > + dev_dbg(&mdev->dev, "MDEV: destroying\n"); > + kfree(mdev); > +} > + > +int mdev_device_create(struct device *dev, uuid_le uuid, uint32_t instance, > + char *mdev_params) > +{ > + int ret; > + struct mdev_device *mdev; > + struct parent_device *parent; > + > + parent = mdev_get_parent_by_dev(dev); > + if (!parent) > + return -EINVAL; > + > + /* Check for duplicate */ > + mdev = find_mdev_device(parent, uuid, instance); > + if (mdev) { > + ret = -EEXIST; > + goto create_err; > + } > + > + mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); > + if (!mdev) { > + ret = -ENOMEM; > + goto create_err; > + } > + > + memcpy(&mdev->uuid, &uuid, sizeof(uuid_le)); > + mdev->instance = instance; > + mdev->parent = parent; > + mutex_init(&mdev->ops_lock); > + kref_init(&mdev->ref); > + > + mdev->dev.parent = dev; > + mdev->dev.bus = &mdev_bus_type; > + mdev->dev.release = mdev_device_release; > + dev_set_name(&mdev->dev, "%pUb-%d", uuid.b, instance); > + > + ret = device_register(&mdev->dev); > + if (ret) { > + put_device(&mdev->dev); > + goto create_err; > + } > + > + ret = mdev_device_create_ops(mdev, mdev_params); > + if (ret) > + goto create_failed; > + > + mutex_lock(&parent->mdev_list_lock); > + list_add(&mdev->next, &parent->mdev_list); > + mutex_unlock(&parent->mdev_list_lock); > + > + dev_dbg(&mdev->dev, "MDEV: created\n"); > + > + return ret; > + > +create_failed: > + device_unregister(&mdev->dev); > + > +create_err: > + mdev_put_parent(parent); > + return ret; > +} > + > +int mdev_device_destroy(struct device *dev, uuid_le uuid, uint32_t instance) > +{ > + struct mdev_device *mdev; > + struct parent_device *parent; > + int ret; > + > + parent = mdev_get_parent_by_dev(dev); > + if (!parent) { > + ret = -EINVAL; > + goto destroy_err; > + } > + > + mdev = find_mdev_device(parent, uuid, instance); > + if (!mdev) { > + ret = -EINVAL; > + goto destroy_err; > + } > + > + ret = mdev_device_destroy_ops(mdev, false); > + if (ret) > + goto destroy_err; find_mdev_device() does not hold the refcount of mdev, is it safe? > + > + mdev_put_parent(parent); > + The refcount of parent-device is released, you can not continue to use it. > + mutex_lock(&parent->mdev_list_lock); > + list_del(&mdev->next); > + mutex_unlock(&parent->mdev_list_lock); > + > + mdev_put_device(mdev); > + return ret; > + > +destroy_err: > + mdev_put_parent(parent); > + return ret; > +} > + > +void mdev_device_supported_config(struct device *dev, char *str) > +{ > + struct parent_device *parent; > + > + parent = mdev_get_parent_by_dev(dev); > + > + if (parent) { > + mutex_lock(&parent->ops_lock); > + if (parent->ops->supported_config) > + parent->ops->supported_config(parent->dev, str); > + mutex_unlock(&parent->ops_lock); > + mdev_put_parent(parent); > + } > +} > + > +int mdev_device_start(uuid_le uuid) > +{ > + int ret = 0; > + struct mdev_device *mdev; > + struct parent_device *parent; > + > + mdev = mdev_get_first_device_by_uuid(uuid); > + if (!mdev) > + return -EINVAL; > + > + parent = mdev->parent; > + > + mutex_lock(&parent->ops_lock); > + if (parent->ops->start) > + ret = parent->ops->start(mdev->uuid); > + mutex_unlock(&parent->ops_lock); > + > + if (ret) > + pr_err("mdev_start failed %d\n", ret); > + else > + kobject_uevent(&mdev->dev.kobj, KOBJ_ONLINE); > + > + mdev_put_device(mdev); > + > + return ret; > +} > + > +int mdev_device_shutdown(uuid_le uuid) > +{ > + int ret = 0; > + struct mdev_device *mdev; > + struct parent_device *parent; > + > + mdev = mdev_get_first_device_by_uuid(uuid); > + if (!mdev) > + return -EINVAL; > + > + parent = mdev->parent; > + > + mutex_lock(&parent->ops_lock); > + if (parent->ops->shutdown) > + ret = parent->ops->shutdown(mdev->uuid); > + mutex_unlock(&parent->ops_lock); > + > + if (ret) > + pr_err("mdev_shutdown failed %d\n", ret); > + else > + kobject_uevent(&mdev->dev.kobj, KOBJ_OFFLINE); > + > + mdev_put_device(mdev); > + return ret; > +} > + > +static struct class mdev_class = { > + .name = MDEV_CLASS_NAME, > + .owner = THIS_MODULE, > + .class_attrs = mdev_class_attrs, These interfaces, start and shutdown, are based on UUID, how about if we want to operate on the specified instance? > +}; > + > +static int __init mdev_init(void) > +{ > + int ret; > + > + mutex_init(&parent_devices.list_lock); > + INIT_LIST_HEAD(&parent_devices.dev_list); > + > + ret = class_register(&mdev_class); > + if (ret) { > + pr_err("Failed to register mdev class\n"); > + return ret; > + } > + > + ret = mdev_bus_register(); > + if (ret) { > + pr_err("Failed to register mdev bus\n"); > + class_unregister(&mdev_class); > + return ret; > + } > + > + return ret; > +} > + > +static void __exit mdev_exit(void) > +{ > + mdev_bus_unregister(); > + class_unregister(&mdev_class); > +} Hmm, how to prevent if there are parent-devices existing when the module is being unloaded? > + > +module_init(mdev_init) > +module_exit(mdev_exit) > + > +MODULE_VERSION(DRIVER_VERSION); > +MODULE_LICENSE("GPL"); > +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 000000000000..f1aed541111d > --- /dev/null > +++ b/drivers/vfio/mdev/mdev_driver.c > @@ -0,0 +1,138 @@ > +/* > + * MDEV driver > + * > + * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved. > + * Author: Neo Jia > + * Kirti Wankhede > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + */ > + > +#include > +#include > +#include > + > +#include "mdev_private.h" > + > +static int mdev_attach_iommu(struct mdev_device *mdev) > +{ > + int ret; > + struct iommu_group *group; > + > + group = iommu_group_alloc(); > + if (IS_ERR(group)) { > + dev_err(&mdev->dev, "MDEV: failed to allocate group!\n"); > + return PTR_ERR(group); > + } > + > + ret = iommu_group_add_device(group, &mdev->dev); > + if (ret) { > + dev_err(&mdev->dev, "MDEV: failed to add dev to group!\n"); > + goto attach_fail; > + } > + > + mdev->group = group; > + > + dev_info(&mdev->dev, "MDEV: group_id = %d\n", > + iommu_group_id(group)); > +attach_fail: > + iommu_group_put(group); > + return ret; > +} > + > +static void mdev_detach_iommu(struct mdev_device *mdev) > +{ > + iommu_group_remove_device(&mdev->dev); > + dev_info(&mdev->dev, "MDEV: detaching iommu\n"); > +} > + > +static int mdev_probe(struct device *dev) > +{ > + struct mdev_driver *drv = to_mdev_driver(dev->driver); > + struct mdev_device *mdev = to_mdev_device(dev); > + int ret; > + > + ret = mdev_attach_iommu(mdev); > + if (ret) { > + dev_err(dev, "Failed to attach IOMMU\n"); > + return ret; > + } > + > + if (drv && drv->probe) > + ret = drv->probe(dev); If probe failed, need to deattache mdev? > + > + return ret; > +} > + > +static int mdev_remove(struct device *dev) > +{ > + struct mdev_driver *drv = to_mdev_driver(dev->driver); > + struct mdev_device *mdev = to_mdev_device(dev); > + > + if (drv && drv->remove) > + drv->remove(dev); > + > + mdev_detach_iommu(mdev); > + > + return 0; > +} > + > +static int mdev_match(struct device *dev, struct device_driver *drv) > +{ > + struct mdev_driver *mdrv = to_mdev_driver(drv); > + > + if (mdrv && mdrv->match) > + return mdrv->match(dev); > + > + return 0; > +} > + > +struct bus_type mdev_bus_type = { > + .name = "mdev", > + .match = mdev_match, > + .probe = mdev_probe, > + .remove = mdev_remove, > +}; > +EXPORT_SYMBOL_GPL(mdev_bus_type); > + > +/* > + * mdev_register_driver - register a new MDEV driver > + * @drv: the driver to register > + * @owner: module owner of driver to be registered > + * > + * Returns a negative value on error, otherwise 0. > + */ > +int mdev_register_driver(struct mdev_driver *drv, struct module *owner) > +{ > + /* initialize common driver fields */ > + drv->driver.name = drv->name; > + drv->driver.bus = &mdev_bus_type; > + drv->driver.owner = owner; > + > + /* register with core */ > + 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); > + > +int mdev_bus_register(void) > +{ > + return bus_register(&mdev_bus_type); > +} > + > +void mdev_bus_unregister(void) > +{ > + bus_unregister(&mdev_bus_type); > +} > diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h > new file mode 100644 > index 000000000000..991d7f796169 > --- /dev/null > +++ b/drivers/vfio/mdev/mdev_private.h > @@ -0,0 +1,33 @@ > +/* > + * Mediated device interal definitions > + * > + * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved. > + * Author: Neo Jia > + * Kirti Wankhede > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + */ > + > +#ifndef MDEV_PRIVATE_H > +#define MDEV_PRIVATE_H > + > +int mdev_bus_register(void); > +void mdev_bus_unregister(void); > + > +/* Function prototypes for mdev_sysfs */ > + > +extern struct class_attribute mdev_class_attrs[]; > + > +int mdev_create_sysfs_files(struct device *dev); > +void mdev_remove_sysfs_files(struct device *dev); > + > +int mdev_device_create(struct device *dev, uuid_le uuid, uint32_t instance, > + char *mdev_params); > +int mdev_device_destroy(struct device *dev, uuid_le uuid, uint32_t instance); > +void mdev_device_supported_config(struct device *dev, char *str); > +int mdev_device_start(uuid_le uuid); > +int mdev_device_shutdown(uuid_le uuid); > + > +#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 000000000000..48b66e40009e > --- /dev/null > +++ b/drivers/vfio/mdev/mdev_sysfs.c > @@ -0,0 +1,300 @@ > +/* > + * File attributes for Mediated devices > + * > + * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved. > + * Author: Neo Jia > + * Kirti Wankhede > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "mdev_private.h" > + > +/* Prototypes */ > +static ssize_t mdev_supported_types_show(struct device *dev, > + struct device_attribute *attr, > + char *buf); > +static DEVICE_ATTR_RO(mdev_supported_types); > + > +static ssize_t mdev_create_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t count); > +static DEVICE_ATTR_WO(mdev_create); > + > +static ssize_t mdev_destroy_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t count); > +static DEVICE_ATTR_WO(mdev_destroy); > + > +/* Static functions */ > + > +#define UUID_CHAR_LENGTH 36 > +#define UUID_BYTE_LENGTH 16 > + > +#define SUPPORTED_TYPE_BUFFER_LENGTH 1024 > + > +static inline bool is_uuid_sep(char sep) > +{ > + if (sep == '\n' || sep == '-' || sep == ':' || sep == '\0') > + return true; > + return false; > +} > + > +static int uuid_parse(const char *str, uuid_le *uuid) > +{ > + int i; > + > + if (strlen(str) < UUID_CHAR_LENGTH) > + return -EINVAL; > + > + for (i = 0; i < UUID_BYTE_LENGTH; i++) { > + if (!isxdigit(str[0]) || !isxdigit(str[1])) { > + pr_err("%s err", __func__); > + return -EINVAL; > + } > + > + uuid->b[i] = (hex_to_bin(str[0]) << 4) | hex_to_bin(str[1]); > + str += 2; > + if (is_uuid_sep(*str)) > + str++; > + } > + > + return 0; > +} > + Can we use uuid_le_to_bin()?