Revision 9e1ff307c779ce1f0f810c7ecce3d95bbae40896 authored by Linus Torvalds on 03 October 2021, 21:08:47 UTC, committed by Linus Torvalds on 03 October 2021, 21:08:47 UTC
1 parent 9b2f72c
vdpa.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* vDPA bus.
*
* Copyright (c) 2020, Red Hat. All rights reserved.
* Author: Jason Wang <jasowang@redhat.com>
*
*/
#include <linux/module.h>
#include <linux/idr.h>
#include <linux/slab.h>
#include <linux/vdpa.h>
#include <uapi/linux/vdpa.h>
#include <net/genetlink.h>
#include <linux/mod_devicetable.h>
static LIST_HEAD(mdev_head);
/* A global mutex that protects vdpa management device and device level operations. */
static DEFINE_MUTEX(vdpa_dev_mutex);
static DEFINE_IDA(vdpa_index_ida);
static struct genl_family vdpa_nl_family;
static int vdpa_dev_probe(struct device *d)
{
struct vdpa_device *vdev = dev_to_vdpa(d);
struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver);
int ret = 0;
if (drv && drv->probe)
ret = drv->probe(vdev);
return ret;
}
static void vdpa_dev_remove(struct device *d)
{
struct vdpa_device *vdev = dev_to_vdpa(d);
struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver);
if (drv && drv->remove)
drv->remove(vdev);
}
static struct bus_type vdpa_bus = {
.name = "vdpa",
.probe = vdpa_dev_probe,
.remove = vdpa_dev_remove,
};
static void vdpa_release_dev(struct device *d)
{
struct vdpa_device *vdev = dev_to_vdpa(d);
const struct vdpa_config_ops *ops = vdev->config;
if (ops->free)
ops->free(vdev);
ida_simple_remove(&vdpa_index_ida, vdev->index);
kfree(vdev);
}
/**
* __vdpa_alloc_device - allocate and initilaize a vDPA device
* This allows driver to some prepartion after device is
* initialized but before registered.
* @parent: the parent device
* @config: the bus operations that is supported by this device
* @size: size of the parent structure that contains private data
* @name: name of the vdpa device; optional.
* @use_va: indicate whether virtual address must be used by this device
*
* Driver should use vdpa_alloc_device() wrapper macro instead of
* using this directly.
*
* Return: Returns an error when parent/config/dma_dev is not set or fail to get
* ida.
*/
struct vdpa_device *__vdpa_alloc_device(struct device *parent,
const struct vdpa_config_ops *config,
size_t size, const char *name,
bool use_va)
{
struct vdpa_device *vdev;
int err = -EINVAL;
if (!config)
goto err;
if (!!config->dma_map != !!config->dma_unmap)
goto err;
/* It should only work for the device that use on-chip IOMMU */
if (use_va && !(config->dma_map || config->set_map))
goto err;
err = -ENOMEM;
vdev = kzalloc(size, GFP_KERNEL);
if (!vdev)
goto err;
err = ida_alloc(&vdpa_index_ida, GFP_KERNEL);
if (err < 0)
goto err_ida;
vdev->dev.bus = &vdpa_bus;
vdev->dev.parent = parent;
vdev->dev.release = vdpa_release_dev;
vdev->index = err;
vdev->config = config;
vdev->features_valid = false;
vdev->use_va = use_va;
if (name)
err = dev_set_name(&vdev->dev, "%s", name);
else
err = dev_set_name(&vdev->dev, "vdpa%u", vdev->index);
if (err)
goto err_name;
device_initialize(&vdev->dev);
return vdev;
err_name:
ida_simple_remove(&vdpa_index_ida, vdev->index);
err_ida:
kfree(vdev);
err:
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(__vdpa_alloc_device);
static int vdpa_name_match(struct device *dev, const void *data)
{
struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);
return (strcmp(dev_name(&vdev->dev), data) == 0);
}
static int __vdpa_register_device(struct vdpa_device *vdev, int nvqs)
{
struct device *dev;
vdev->nvqs = nvqs;
lockdep_assert_held(&vdpa_dev_mutex);
dev = bus_find_device(&vdpa_bus, NULL, dev_name(&vdev->dev), vdpa_name_match);
if (dev) {
put_device(dev);
return -EEXIST;
}
return device_add(&vdev->dev);
}
/**
* _vdpa_register_device - register a vDPA device with vdpa lock held
* Caller must have a succeed call of vdpa_alloc_device() before.
* Caller must invoke this routine in the management device dev_add()
* callback after setting up valid mgmtdev for this vdpa device.
* @vdev: the vdpa device to be registered to vDPA bus
* @nvqs: number of virtqueues supported by this device
*
* Return: Returns an error when fail to add device to vDPA bus
*/
int _vdpa_register_device(struct vdpa_device *vdev, int nvqs)
{
if (!vdev->mdev)
return -EINVAL;
return __vdpa_register_device(vdev, nvqs);
}
EXPORT_SYMBOL_GPL(_vdpa_register_device);
/**
* vdpa_register_device - register a vDPA device
* Callers must have a succeed call of vdpa_alloc_device() before.
* @vdev: the vdpa device to be registered to vDPA bus
* @nvqs: number of virtqueues supported by this device
*
* Return: Returns an error when fail to add to vDPA bus
*/
int vdpa_register_device(struct vdpa_device *vdev, int nvqs)
{
int err;
mutex_lock(&vdpa_dev_mutex);
err = __vdpa_register_device(vdev, nvqs);
mutex_unlock(&vdpa_dev_mutex);
return err;
}
EXPORT_SYMBOL_GPL(vdpa_register_device);
/**
* _vdpa_unregister_device - unregister a vDPA device
* Caller must invoke this routine as part of management device dev_del()
* callback.
* @vdev: the vdpa device to be unregisted from vDPA bus
*/
void _vdpa_unregister_device(struct vdpa_device *vdev)
{
lockdep_assert_held(&vdpa_dev_mutex);
WARN_ON(!vdev->mdev);
device_unregister(&vdev->dev);
}
EXPORT_SYMBOL_GPL(_vdpa_unregister_device);
/**
* vdpa_unregister_device - unregister a vDPA device
* @vdev: the vdpa device to be unregisted from vDPA bus
*/
void vdpa_unregister_device(struct vdpa_device *vdev)
{
mutex_lock(&vdpa_dev_mutex);
device_unregister(&vdev->dev);
mutex_unlock(&vdpa_dev_mutex);
}
EXPORT_SYMBOL_GPL(vdpa_unregister_device);
/**
* __vdpa_register_driver - register a vDPA device driver
* @drv: the vdpa device driver to be registered
* @owner: module owner of the driver
*
* Return: Returns an err when fail to do the registration
*/
int __vdpa_register_driver(struct vdpa_driver *drv, struct module *owner)
{
drv->driver.bus = &vdpa_bus;
drv->driver.owner = owner;
return driver_register(&drv->driver);
}
EXPORT_SYMBOL_GPL(__vdpa_register_driver);
/**
* vdpa_unregister_driver - unregister a vDPA device driver
* @drv: the vdpa device driver to be unregistered
*/
void vdpa_unregister_driver(struct vdpa_driver *drv)
{
driver_unregister(&drv->driver);
}
EXPORT_SYMBOL_GPL(vdpa_unregister_driver);
/**
* vdpa_mgmtdev_register - register a vdpa management device
*
* @mdev: Pointer to vdpa management device
* vdpa_mgmtdev_register() register a vdpa management device which supports
* vdpa device management.
* Return: Returns 0 on success or failure when required callback ops are not
* initialized.
*/
int vdpa_mgmtdev_register(struct vdpa_mgmt_dev *mdev)
{
if (!mdev->device || !mdev->ops || !mdev->ops->dev_add || !mdev->ops->dev_del)
return -EINVAL;
INIT_LIST_HEAD(&mdev->list);
mutex_lock(&vdpa_dev_mutex);
list_add_tail(&mdev->list, &mdev_head);
mutex_unlock(&vdpa_dev_mutex);
return 0;
}
EXPORT_SYMBOL_GPL(vdpa_mgmtdev_register);
static int vdpa_match_remove(struct device *dev, void *data)
{
struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);
struct vdpa_mgmt_dev *mdev = vdev->mdev;
if (mdev == data)
mdev->ops->dev_del(mdev, vdev);
return 0;
}
void vdpa_mgmtdev_unregister(struct vdpa_mgmt_dev *mdev)
{
mutex_lock(&vdpa_dev_mutex);
list_del(&mdev->list);
/* Filter out all the entries belong to this management device and delete it. */
bus_for_each_dev(&vdpa_bus, NULL, mdev, vdpa_match_remove);
mutex_unlock(&vdpa_dev_mutex);
}
EXPORT_SYMBOL_GPL(vdpa_mgmtdev_unregister);
static bool mgmtdev_handle_match(const struct vdpa_mgmt_dev *mdev,
const char *busname, const char *devname)
{
/* Bus name is optional for simulated management device, so ignore the
* device with bus if bus attribute is provided.
*/
if ((busname && !mdev->device->bus) || (!busname && mdev->device->bus))
return false;
if (!busname && strcmp(dev_name(mdev->device), devname) == 0)
return true;
if (busname && (strcmp(mdev->device->bus->name, busname) == 0) &&
(strcmp(dev_name(mdev->device), devname) == 0))
return true;
return false;
}
static struct vdpa_mgmt_dev *vdpa_mgmtdev_get_from_attr(struct nlattr **attrs)
{
struct vdpa_mgmt_dev *mdev;
const char *busname = NULL;
const char *devname;
if (!attrs[VDPA_ATTR_MGMTDEV_DEV_NAME])
return ERR_PTR(-EINVAL);
devname = nla_data(attrs[VDPA_ATTR_MGMTDEV_DEV_NAME]);
if (attrs[VDPA_ATTR_MGMTDEV_BUS_NAME])
busname = nla_data(attrs[VDPA_ATTR_MGMTDEV_BUS_NAME]);
list_for_each_entry(mdev, &mdev_head, list) {
if (mgmtdev_handle_match(mdev, busname, devname))
return mdev;
}
return ERR_PTR(-ENODEV);
}
static int vdpa_nl_mgmtdev_handle_fill(struct sk_buff *msg, const struct vdpa_mgmt_dev *mdev)
{
if (mdev->device->bus &&
nla_put_string(msg, VDPA_ATTR_MGMTDEV_BUS_NAME, mdev->device->bus->name))
return -EMSGSIZE;
if (nla_put_string(msg, VDPA_ATTR_MGMTDEV_DEV_NAME, dev_name(mdev->device)))
return -EMSGSIZE;
return 0;
}
static int vdpa_mgmtdev_fill(const struct vdpa_mgmt_dev *mdev, struct sk_buff *msg,
u32 portid, u32 seq, int flags)
{
u64 supported_classes = 0;
void *hdr;
int i = 0;
int err;
hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags, VDPA_CMD_MGMTDEV_NEW);
if (!hdr)
return -EMSGSIZE;
err = vdpa_nl_mgmtdev_handle_fill(msg, mdev);
if (err)
goto msg_err;
while (mdev->id_table[i].device) {
supported_classes |= BIT(mdev->id_table[i].device);
i++;
}
if (nla_put_u64_64bit(msg, VDPA_ATTR_MGMTDEV_SUPPORTED_CLASSES,
supported_classes, VDPA_ATTR_UNSPEC)) {
err = -EMSGSIZE;
goto msg_err;
}
genlmsg_end(msg, hdr);
return 0;
msg_err:
genlmsg_cancel(msg, hdr);
return err;
}
static int vdpa_nl_cmd_mgmtdev_get_doit(struct sk_buff *skb, struct genl_info *info)
{
struct vdpa_mgmt_dev *mdev;
struct sk_buff *msg;
int err;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
mutex_lock(&vdpa_dev_mutex);
mdev = vdpa_mgmtdev_get_from_attr(info->attrs);
if (IS_ERR(mdev)) {
mutex_unlock(&vdpa_dev_mutex);
NL_SET_ERR_MSG_MOD(info->extack, "Fail to find the specified mgmt device");
err = PTR_ERR(mdev);
goto out;
}
err = vdpa_mgmtdev_fill(mdev, msg, info->snd_portid, info->snd_seq, 0);
mutex_unlock(&vdpa_dev_mutex);
if (err)
goto out;
err = genlmsg_reply(msg, info);
return err;
out:
nlmsg_free(msg);
return err;
}
static int
vdpa_nl_cmd_mgmtdev_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb)
{
struct vdpa_mgmt_dev *mdev;
int start = cb->args[0];
int idx = 0;
int err;
mutex_lock(&vdpa_dev_mutex);
list_for_each_entry(mdev, &mdev_head, list) {
if (idx < start) {
idx++;
continue;
}
err = vdpa_mgmtdev_fill(mdev, msg, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI);
if (err)
goto out;
idx++;
}
out:
mutex_unlock(&vdpa_dev_mutex);
cb->args[0] = idx;
return msg->len;
}
static int vdpa_nl_cmd_dev_add_set_doit(struct sk_buff *skb, struct genl_info *info)
{
struct vdpa_mgmt_dev *mdev;
const char *name;
int err = 0;
if (!info->attrs[VDPA_ATTR_DEV_NAME])
return -EINVAL;
name = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
mutex_lock(&vdpa_dev_mutex);
mdev = vdpa_mgmtdev_get_from_attr(info->attrs);
if (IS_ERR(mdev)) {
NL_SET_ERR_MSG_MOD(info->extack, "Fail to find the specified management device");
err = PTR_ERR(mdev);
goto err;
}
err = mdev->ops->dev_add(mdev, name);
err:
mutex_unlock(&vdpa_dev_mutex);
return err;
}
static int vdpa_nl_cmd_dev_del_set_doit(struct sk_buff *skb, struct genl_info *info)
{
struct vdpa_mgmt_dev *mdev;
struct vdpa_device *vdev;
struct device *dev;
const char *name;
int err = 0;
if (!info->attrs[VDPA_ATTR_DEV_NAME])
return -EINVAL;
name = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
mutex_lock(&vdpa_dev_mutex);
dev = bus_find_device(&vdpa_bus, NULL, name, vdpa_name_match);
if (!dev) {
NL_SET_ERR_MSG_MOD(info->extack, "device not found");
err = -ENODEV;
goto dev_err;
}
vdev = container_of(dev, struct vdpa_device, dev);
if (!vdev->mdev) {
NL_SET_ERR_MSG_MOD(info->extack, "Only user created device can be deleted by user");
err = -EINVAL;
goto mdev_err;
}
mdev = vdev->mdev;
mdev->ops->dev_del(mdev, vdev);
mdev_err:
put_device(dev);
dev_err:
mutex_unlock(&vdpa_dev_mutex);
return err;
}
static int
vdpa_dev_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq,
int flags, struct netlink_ext_ack *extack)
{
u16 max_vq_size;
u32 device_id;
u32 vendor_id;
void *hdr;
int err;
hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags, VDPA_CMD_DEV_NEW);
if (!hdr)
return -EMSGSIZE;
err = vdpa_nl_mgmtdev_handle_fill(msg, vdev->mdev);
if (err)
goto msg_err;
device_id = vdev->config->get_device_id(vdev);
vendor_id = vdev->config->get_vendor_id(vdev);
max_vq_size = vdev->config->get_vq_num_max(vdev);
err = -EMSGSIZE;
if (nla_put_string(msg, VDPA_ATTR_DEV_NAME, dev_name(&vdev->dev)))
goto msg_err;
if (nla_put_u32(msg, VDPA_ATTR_DEV_ID, device_id))
goto msg_err;
if (nla_put_u32(msg, VDPA_ATTR_DEV_VENDOR_ID, vendor_id))
goto msg_err;
if (nla_put_u32(msg, VDPA_ATTR_DEV_MAX_VQS, vdev->nvqs))
goto msg_err;
if (nla_put_u16(msg, VDPA_ATTR_DEV_MAX_VQ_SIZE, max_vq_size))
goto msg_err;
genlmsg_end(msg, hdr);
return 0;
msg_err:
genlmsg_cancel(msg, hdr);
return err;
}
static int vdpa_nl_cmd_dev_get_doit(struct sk_buff *skb, struct genl_info *info)
{
struct vdpa_device *vdev;
struct sk_buff *msg;
const char *devname;
struct device *dev;
int err;
if (!info->attrs[VDPA_ATTR_DEV_NAME])
return -EINVAL;
devname = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
mutex_lock(&vdpa_dev_mutex);
dev = bus_find_device(&vdpa_bus, NULL, devname, vdpa_name_match);
if (!dev) {
NL_SET_ERR_MSG_MOD(info->extack, "device not found");
err = -ENODEV;
goto err;
}
vdev = container_of(dev, struct vdpa_device, dev);
if (!vdev->mdev) {
err = -EINVAL;
goto mdev_err;
}
err = vdpa_dev_fill(vdev, msg, info->snd_portid, info->snd_seq, 0, info->extack);
if (!err)
err = genlmsg_reply(msg, info);
mdev_err:
put_device(dev);
err:
mutex_unlock(&vdpa_dev_mutex);
if (err)
nlmsg_free(msg);
return err;
}
struct vdpa_dev_dump_info {
struct sk_buff *msg;
struct netlink_callback *cb;
int start_idx;
int idx;
};
static int vdpa_dev_dump(struct device *dev, void *data)
{
struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);
struct vdpa_dev_dump_info *info = data;
int err;
if (!vdev->mdev)
return 0;
if (info->idx < info->start_idx) {
info->idx++;
return 0;
}
err = vdpa_dev_fill(vdev, info->msg, NETLINK_CB(info->cb->skb).portid,
info->cb->nlh->nlmsg_seq, NLM_F_MULTI, info->cb->extack);
if (err)
return err;
info->idx++;
return 0;
}
static int vdpa_nl_cmd_dev_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb)
{
struct vdpa_dev_dump_info info;
info.msg = msg;
info.cb = cb;
info.start_idx = cb->args[0];
info.idx = 0;
mutex_lock(&vdpa_dev_mutex);
bus_for_each_dev(&vdpa_bus, NULL, &info, vdpa_dev_dump);
mutex_unlock(&vdpa_dev_mutex);
cb->args[0] = info.idx;
return msg->len;
}
static const struct nla_policy vdpa_nl_policy[VDPA_ATTR_MAX + 1] = {
[VDPA_ATTR_MGMTDEV_BUS_NAME] = { .type = NLA_NUL_STRING },
[VDPA_ATTR_MGMTDEV_DEV_NAME] = { .type = NLA_STRING },
[VDPA_ATTR_DEV_NAME] = { .type = NLA_STRING },
};
static const struct genl_ops vdpa_nl_ops[] = {
{
.cmd = VDPA_CMD_MGMTDEV_GET,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = vdpa_nl_cmd_mgmtdev_get_doit,
.dumpit = vdpa_nl_cmd_mgmtdev_get_dumpit,
},
{
.cmd = VDPA_CMD_DEV_NEW,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = vdpa_nl_cmd_dev_add_set_doit,
.flags = GENL_ADMIN_PERM,
},
{
.cmd = VDPA_CMD_DEV_DEL,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = vdpa_nl_cmd_dev_del_set_doit,
.flags = GENL_ADMIN_PERM,
},
{
.cmd = VDPA_CMD_DEV_GET,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.doit = vdpa_nl_cmd_dev_get_doit,
.dumpit = vdpa_nl_cmd_dev_get_dumpit,
},
};
static struct genl_family vdpa_nl_family __ro_after_init = {
.name = VDPA_GENL_NAME,
.version = VDPA_GENL_VERSION,
.maxattr = VDPA_ATTR_MAX,
.policy = vdpa_nl_policy,
.netnsok = false,
.module = THIS_MODULE,
.ops = vdpa_nl_ops,
.n_ops = ARRAY_SIZE(vdpa_nl_ops),
};
static int vdpa_init(void)
{
int err;
err = bus_register(&vdpa_bus);
if (err)
return err;
err = genl_register_family(&vdpa_nl_family);
if (err)
goto err;
return 0;
err:
bus_unregister(&vdpa_bus);
return err;
}
static void __exit vdpa_exit(void)
{
genl_unregister_family(&vdpa_nl_family);
bus_unregister(&vdpa_bus);
ida_destroy(&vdpa_index_ida);
}
core_initcall(vdpa_init);
module_exit(vdpa_exit);
MODULE_AUTHOR("Jason Wang <jasowang@redhat.com>");
MODULE_LICENSE("GPL v2");
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