// 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/virtio_ids.h>

static LIST_HEAD(mdev_head);
/* A global mutex that protects vdpa management device and device level operations. */
static DECLARE_RWSEM(vdpa_dev_lock);
static DEFINE_IDA(vdpa_index_ida);

void vdpa_set_status(struct vdpa_device *vdev, u8 status)
{
        down_write(&vdev->cf_lock);
        vdev->config->set_status(vdev, status);
        up_write(&vdev->cf_lock);
}
EXPORT_SYMBOL(vdpa_set_status);

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);
        const struct vdpa_config_ops *ops = vdev->config;
        u32 max_num, min_num = 1;
        int ret = 0;

        d->dma_mask = &d->coherent_dma_mask;
        ret = dma_set_mask_and_coherent(d, DMA_BIT_MASK(64));
        if (ret)
                return ret;

        max_num = ops->get_vq_num_max(vdev);
        if (ops->get_vq_num_min)
                min_num = ops->get_vq_num_min(vdev);
        if (max_num < min_num)
                return -EINVAL;

        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 int vdpa_dev_match(struct device *dev, const struct device_driver *drv)
{
        int ret;

        /* Check override first, and if set, only use the named driver */
        ret = device_match_driver_override(dev, drv);
        if (ret >= 0)
                return ret;

        /* Currently devices must be supported by all vDPA bus drivers */
        return 1;
}

static const struct bus_type vdpa_bus = {
        .name  = "vdpa",
        .driver_override = true,
        .match = vdpa_dev_match,
        .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_free(&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
 * @map: the map operations that is supported by this device
 * @ngroups: number of groups supported by this device
 * @nas: number of address spaces 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/map is not set or fail to get
 *         ida.
 */
struct vdpa_device *__vdpa_alloc_device(struct device *parent,
                                        const struct vdpa_config_ops *config,
                                        const struct virtio_map_ops *map,
                                        unsigned int ngroups, unsigned int nas,
                                        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->map = map;
        vdev->features_valid = false;
        vdev->use_va = use_va;
        vdev->ngroups = ngroups;
        vdev->nas = nas;

        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;

        init_rwsem(&vdev->cf_lock);
        device_initialize(&vdev->dev);

        return vdev;

err_name:
        ida_free(&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, u32 nvqs)
{
        struct device *dev;

        vdev->nvqs = nvqs;

        lockdep_assert_held(&vdpa_dev_lock);
        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, u32 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, u32 nvqs)
{
        int err;

        down_write(&vdpa_dev_lock);
        err = __vdpa_register_device(vdev, nvqs);
        up_write(&vdpa_dev_lock);
        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_lock);
        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)
{
        down_write(&vdpa_dev_lock);
        device_unregister(&vdev->dev);
        up_write(&vdpa_dev_lock);
}
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);
        down_write(&vdpa_dev_lock);
        list_add_tail(&mdev->list, &mdev_head);
        up_write(&vdpa_dev_lock);
        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)
{
        down_write(&vdpa_dev_lock);

        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);

        up_write(&vdpa_dev_lock);
}
EXPORT_SYMBOL_GPL(vdpa_mgmtdev_unregister);

static void vdpa_get_config_unlocked(struct vdpa_device *vdev,
                                     unsigned int offset,
                                     void *buf, unsigned int len)
{
        const struct vdpa_config_ops *ops = vdev->config;

        /*
         * Config accesses aren't supposed to trigger before features are set.
         * If it does happen we assume a legacy guest.
         */
        if (!vdev->features_valid)
                vdpa_set_features_unlocked(vdev, 0);
        ops->get_config(vdev, offset, buf, len);
}

/**
 * vdpa_get_config - Get one or more device configuration fields.
 * @vdev: vdpa device to operate on
 * @offset: starting byte offset of the field
 * @buf: buffer pointer to read to
 * @len: length of the configuration fields in bytes
 */
void vdpa_get_config(struct vdpa_device *vdev, unsigned int offset,
                     void *buf, unsigned int len)
{
        down_read(&vdev->cf_lock);
        vdpa_get_config_unlocked(vdev, offset, buf, len);
        up_read(&vdev->cf_lock);
}
EXPORT_SYMBOL_GPL(vdpa_get_config);

/**
 * vdpa_set_config - Set one or more device configuration fields.
 * @vdev: vdpa device to operate on
 * @offset: starting byte offset of the field
 * @buf: buffer pointer to read from
 * @length: length of the configuration fields in bytes
 */
void vdpa_set_config(struct vdpa_device *vdev, unsigned int offset,
                     const void *buf, unsigned int length)
{
        down_write(&vdev->cf_lock);
        vdev->config->set_config(vdev, offset, buf, length);
        up_write(&vdev->cf_lock);
}
EXPORT_SYMBOL_GPL(vdpa_set_config);

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 u64 vdpa_mgmtdev_get_classes(const struct vdpa_mgmt_dev *mdev,
                                    unsigned int *nclasses)
{
        u64 supported_classes = 0;
        unsigned int n = 0;

        for (int i = 0; mdev->id_table[i].device; i++) {
                if (mdev->id_table[i].device > 63)
                        continue;
                supported_classes |= BIT_ULL(mdev->id_table[i].device);
                n++;
        }
        if (nclasses)
                *nclasses = n;

        return supported_classes;
}

static int vdpa_mgmtdev_fill(const struct vdpa_mgmt_dev *mdev, struct sk_buff *msg,
                             u32 portid, u32 seq, int flags)
{
        void *hdr;
        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;

        if (nla_put_u64_64bit(msg, VDPA_ATTR_MGMTDEV_SUPPORTED_CLASSES,
                              vdpa_mgmtdev_get_classes(mdev, NULL),
                              VDPA_ATTR_UNSPEC)) {
                err = -EMSGSIZE;
                goto msg_err;
        }
        if (nla_put_u32(msg, VDPA_ATTR_DEV_MGMTDEV_MAX_VQS,
                        mdev->max_supported_vqs)) {
                err = -EMSGSIZE;
                goto msg_err;
        }
        if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_SUPPORTED_FEATURES,
                              mdev->supported_features, VDPA_ATTR_PAD)) {
                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;

        down_read(&vdpa_dev_lock);
        mdev = vdpa_mgmtdev_get_from_attr(info->attrs);
        if (IS_ERR(mdev)) {
                up_read(&vdpa_dev_lock);
                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);
        up_read(&vdpa_dev_lock);
        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;

        down_read(&vdpa_dev_lock);
        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:
        up_read(&vdpa_dev_lock);
        cb->args[0] = idx;
        return msg->len;
}

#define VDPA_DEV_NET_ATTRS_MASK (BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MACADDR) | \
                                 BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MTU)     | \
                                 BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP))

/*
 * Bitmask for all per-device features: feature bits VIRTIO_TRANSPORT_F_START
 * through VIRTIO_TRANSPORT_F_END are unset, i.e. 0xfffffc000fffffff for
 * all 64bit features. If the features are extended beyond 64 bits, or new
 * "holes" are reserved for other type of features than per-device, this
 * macro would have to be updated.
 */
#define VIRTIO_DEVICE_F_MASK (~0ULL << (VIRTIO_TRANSPORT_F_END + 1) | \
                              ((1ULL << VIRTIO_TRANSPORT_F_START) - 1))

static int vdpa_nl_cmd_dev_add_set_doit(struct sk_buff *skb, struct genl_info *info)
{
        struct vdpa_dev_set_config config = {};
        struct nlattr **nl_attrs = info->attrs;
        struct vdpa_mgmt_dev *mdev;
        unsigned int ncls = 0;
        const u8 *macaddr;
        const char *name;
        u64 classes;
        int err = 0;

        if (!info->attrs[VDPA_ATTR_DEV_NAME])
                return -EINVAL;

        name = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);

        if (nl_attrs[VDPA_ATTR_DEV_NET_CFG_MACADDR]) {
                macaddr = nla_data(nl_attrs[VDPA_ATTR_DEV_NET_CFG_MACADDR]);
                memcpy(config.net.mac, macaddr, sizeof(config.net.mac));
                config.mask |= BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MACADDR);
        }
        if (nl_attrs[VDPA_ATTR_DEV_NET_CFG_MTU]) {
                config.net.mtu =
                        nla_get_u16(nl_attrs[VDPA_ATTR_DEV_NET_CFG_MTU]);
                config.mask |= BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MTU);
        }
        if (nl_attrs[VDPA_ATTR_DEV_NET_CFG_MAX_VQP]) {
                config.net.max_vq_pairs =
                        nla_get_u16(nl_attrs[VDPA_ATTR_DEV_NET_CFG_MAX_VQP]);
                if (!config.net.max_vq_pairs) {
                        NL_SET_ERR_MSG_MOD(info->extack,
                                           "At least one pair of VQs is required");
                        return -EINVAL;
                }
                config.mask |= BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MAX_VQP);
        }
        if (nl_attrs[VDPA_ATTR_DEV_FEATURES]) {
                u64 missing = 0x0ULL;

                config.device_features =
                        nla_get_u64(nl_attrs[VDPA_ATTR_DEV_FEATURES]);
                if (nl_attrs[VDPA_ATTR_DEV_NET_CFG_MACADDR] &&
                    !(config.device_features & BIT_ULL(VIRTIO_NET_F_MAC)))
                        missing |= BIT_ULL(VIRTIO_NET_F_MAC);
                if (nl_attrs[VDPA_ATTR_DEV_NET_CFG_MTU] &&
                    !(config.device_features & BIT_ULL(VIRTIO_NET_F_MTU)))
                        missing |= BIT_ULL(VIRTIO_NET_F_MTU);
                if (nl_attrs[VDPA_ATTR_DEV_NET_CFG_MAX_VQP] &&
                    config.net.max_vq_pairs > 1 &&
                    !(config.device_features & BIT_ULL(VIRTIO_NET_F_MQ)))
                        missing |= BIT_ULL(VIRTIO_NET_F_MQ);
                if (missing) {
                        NL_SET_ERR_MSG_FMT_MOD(info->extack,
                                               "Missing features 0x%llx for provided attributes",
                                               missing);
                        return -EINVAL;
                }
                config.mask |= BIT_ULL(VDPA_ATTR_DEV_FEATURES);
        }

        /* Skip checking capability if user didn't prefer to configure any
         * device networking attributes. It is likely that user might have used
         * a device specific method to configure such attributes or using device
         * default attributes.
         */
        if ((config.mask & VDPA_DEV_NET_ATTRS_MASK) &&
            !netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;

        down_write(&vdpa_dev_lock);
        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;
        }

        if ((config.mask & mdev->config_attr_mask) != config.mask) {
                NL_SET_ERR_MSG_FMT_MOD(info->extack,
                                       "Some provided attributes are not supported: 0x%llx",
                                       config.mask & ~mdev->config_attr_mask);
                err = -EOPNOTSUPP;
                goto err;
        }

        classes = vdpa_mgmtdev_get_classes(mdev, &ncls);
        if (config.mask & VDPA_DEV_NET_ATTRS_MASK &&
            !(classes & BIT_ULL(VIRTIO_ID_NET))) {
                NL_SET_ERR_MSG_MOD(info->extack,
                                   "Network class attributes provided on unsupported management device");
                err = -EINVAL;
                goto err;
        }
        if (!(config.mask & VDPA_DEV_NET_ATTRS_MASK) &&
            config.mask & BIT_ULL(VDPA_ATTR_DEV_FEATURES) &&
            classes & BIT_ULL(VIRTIO_ID_NET) && ncls > 1 &&
            config.device_features & VIRTIO_DEVICE_F_MASK) {
                NL_SET_ERR_MSG_MOD(info->extack,
                                   "Management device supports multi-class while device features specified are ambiguous");
                err = -EINVAL;
                goto err;
        }

        err = mdev->ops->dev_add(mdev, name, &config);
err:
        up_write(&vdpa_dev_lock);
        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]);

        down_write(&vdpa_dev_lock);
        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:
        up_write(&vdpa_dev_lock);
        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;
        u16 min_vq_size = 1;
        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);
        if (vdev->config->get_vq_num_min)
                min_vq_size = vdev->config->get_vq_num_min(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;
        if (nla_put_u16(msg, VDPA_ATTR_DEV_MIN_VQ_SIZE, min_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;

        down_read(&vdpa_dev_lock);
        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)
                goto mdev_err;

        err = genlmsg_reply(msg, info);
        put_device(dev);
        up_read(&vdpa_dev_lock);
        return err;

mdev_err:
        put_device(dev);
err:
        up_read(&vdpa_dev_lock);
        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;

        down_read(&vdpa_dev_lock);
        bus_for_each_dev(&vdpa_bus, NULL, &info, vdpa_dev_dump);
        up_read(&vdpa_dev_lock);
        cb->args[0] = info.idx;
        return msg->len;
}

static int vdpa_dev_net_mq_config_fill(struct sk_buff *msg, u64 features,
                                       const struct virtio_net_config *config)
{
        u16 val_u16;

        if ((features & BIT_ULL(VIRTIO_NET_F_MQ)) == 0 &&
            (features & BIT_ULL(VIRTIO_NET_F_RSS)) == 0)
                return 0;

        val_u16 = __virtio16_to_cpu(true, config->max_virtqueue_pairs);

        return nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MAX_VQP, val_u16);
}

static int vdpa_dev_net_mtu_config_fill(struct sk_buff *msg, u64 features,
                                        const struct virtio_net_config *config)
{
        u16 val_u16;

        if ((features & BIT_ULL(VIRTIO_NET_F_MTU)) == 0)
                return 0;

        val_u16 = __virtio16_to_cpu(true, config->mtu);

        return nla_put_u16(msg, VDPA_ATTR_DEV_NET_CFG_MTU, val_u16);
}

static int vdpa_dev_net_mac_config_fill(struct sk_buff *msg, u64 features,
                                        const struct virtio_net_config *config)
{
        if ((features & BIT_ULL(VIRTIO_NET_F_MAC)) == 0)
                return 0;

        return  nla_put(msg, VDPA_ATTR_DEV_NET_CFG_MACADDR,
                        sizeof(config->mac), config->mac);
}

static int vdpa_dev_net_status_config_fill(struct sk_buff *msg, u64 features,
                                           const struct virtio_net_config *config)
{
        u16 val_u16;

        if ((features & BIT_ULL(VIRTIO_NET_F_STATUS)) == 0)
                return 0;

        val_u16 = __virtio16_to_cpu(true, config->status);
        return nla_put_u16(msg, VDPA_ATTR_DEV_NET_STATUS, val_u16);
}

static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *msg)
{
        struct virtio_net_config config = {};
        u64 features_device;

        vdev->config->get_config(vdev, 0, &config, sizeof(config));

        features_device = vdev->config->get_device_features(vdev);

        if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_FEATURES, features_device,
                              VDPA_ATTR_PAD))
                return -EMSGSIZE;

        if (vdpa_dev_net_mtu_config_fill(msg, features_device, &config))
                return -EMSGSIZE;

        if (vdpa_dev_net_mac_config_fill(msg, features_device, &config))
                return -EMSGSIZE;

        if (vdpa_dev_net_status_config_fill(msg, features_device, &config))
                return -EMSGSIZE;

        return vdpa_dev_net_mq_config_fill(msg, features_device, &config);
}

static int
vdpa_dev_blk_capacity_config_fill(struct sk_buff *msg,
                                  const struct virtio_blk_config *config)
{
        u64 val_u64;

        val_u64 = __virtio64_to_cpu(true, config->capacity);

        return nla_put_u64_64bit(msg, VDPA_ATTR_DEV_BLK_CFG_CAPACITY,
                                 val_u64, VDPA_ATTR_PAD);
}

static int
vdpa_dev_blk_seg_size_config_fill(struct sk_buff *msg, u64 features,
                                  const struct virtio_blk_config *config)
{
        u32 val_u32;

        if ((features & BIT_ULL(VIRTIO_BLK_F_SIZE_MAX)) == 0)
                return 0;

        val_u32 = __virtio32_to_cpu(true, config->size_max);

        return nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_SIZE_MAX, val_u32);
}

/* fill the block size*/
static int
vdpa_dev_blk_block_size_config_fill(struct sk_buff *msg, u64 features,
                                    const struct virtio_blk_config *config)
{
        u32 val_u32;

        if ((features & BIT_ULL(VIRTIO_BLK_F_BLK_SIZE)) == 0)
                return 0;

        val_u32 = __virtio32_to_cpu(true, config->blk_size);

        return nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_BLK_SIZE, val_u32);
}

static int
vdpa_dev_blk_seg_max_config_fill(struct sk_buff *msg, u64 features,
                                 const struct virtio_blk_config *config)
{
        u32 val_u32;

        if ((features & BIT_ULL(VIRTIO_BLK_F_SEG_MAX)) == 0)
                return 0;

        val_u32 = __virtio32_to_cpu(true, config->seg_max);

        return nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_SEG_MAX, val_u32);
}

static int vdpa_dev_blk_mq_config_fill(struct sk_buff *msg, u64 features,
                                       const struct virtio_blk_config *config)
{
        u16 val_u16;

        if ((features & BIT_ULL(VIRTIO_BLK_F_MQ)) == 0)
                return 0;

        val_u16 = __virtio16_to_cpu(true, config->num_queues);

        return nla_put_u16(msg, VDPA_ATTR_DEV_BLK_CFG_NUM_QUEUES, val_u16);
}

static int vdpa_dev_blk_topology_config_fill(struct sk_buff *msg, u64 features,
                                       const struct virtio_blk_config *config)
{
        u16 min_io_size;
        u32 opt_io_size;

        if ((features & BIT_ULL(VIRTIO_BLK_F_TOPOLOGY)) == 0)
                return 0;

        min_io_size = __virtio16_to_cpu(true, config->min_io_size);
        opt_io_size = __virtio32_to_cpu(true, config->opt_io_size);

        if (nla_put_u8(msg, VDPA_ATTR_DEV_BLK_CFG_PHY_BLK_EXP,
            config->physical_block_exp))
                return -EMSGSIZE;

        if (nla_put_u8(msg, VDPA_ATTR_DEV_BLK_CFG_ALIGN_OFFSET,
            config->alignment_offset))
                return -EMSGSIZE;

        if (nla_put_u16(msg, VDPA_ATTR_DEV_BLK_CFG_MIN_IO_SIZE, min_io_size))
                return -EMSGSIZE;

        if (nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_OPT_IO_SIZE, opt_io_size))
                return -EMSGSIZE;

        return 0;
}

static int vdpa_dev_blk_discard_config_fill(struct sk_buff *msg, u64 features,
                                       const struct virtio_blk_config *config)
{
        u32 val_u32;

        if ((features & BIT_ULL(VIRTIO_BLK_F_DISCARD)) == 0)
                return 0;

        val_u32 = __virtio32_to_cpu(true, config->max_discard_sectors);
        if (nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_MAX_DISCARD_SEC, val_u32))
                return -EMSGSIZE;

        val_u32 = __virtio32_to_cpu(true, config->max_discard_seg);
        if (nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_MAX_DISCARD_SEG, val_u32))
                return -EMSGSIZE;

        val_u32 = __virtio32_to_cpu(true, config->discard_sector_alignment);
        if (nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_DISCARD_SEC_ALIGN, val_u32))
                return -EMSGSIZE;

        return 0;
}

static int
vdpa_dev_blk_write_zeroes_config_fill(struct sk_buff *msg, u64 features,
                                     const struct virtio_blk_config *config)
{
        u32 val_u32;

        if ((features & BIT_ULL(VIRTIO_BLK_F_WRITE_ZEROES)) == 0)
                return 0;

        val_u32 = __virtio32_to_cpu(true, config->max_write_zeroes_sectors);
        if (nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_MAX_WRITE_ZEROES_SEC, val_u32))
                return -EMSGSIZE;

        val_u32 = __virtio32_to_cpu(true, config->max_write_zeroes_seg);
        if (nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_MAX_WRITE_ZEROES_SEG, val_u32))
                return -EMSGSIZE;

        return 0;
}

static int vdpa_dev_blk_ro_config_fill(struct sk_buff *msg, u64 features)
{
        u8 ro;

        ro = ((features & BIT_ULL(VIRTIO_BLK_F_RO)) == 0) ? 0 : 1;
        if (nla_put_u8(msg, VDPA_ATTR_DEV_BLK_READ_ONLY, ro))
                return -EMSGSIZE;

        return 0;
}

static int vdpa_dev_blk_flush_config_fill(struct sk_buff *msg, u64 features)
{
        u8 flush;

        flush = ((features & BIT_ULL(VIRTIO_BLK_F_FLUSH)) == 0) ? 0 : 1;
        if (nla_put_u8(msg, VDPA_ATTR_DEV_BLK_FLUSH, flush))
                return -EMSGSIZE;

        return 0;
}

static int vdpa_dev_blk_config_fill(struct vdpa_device *vdev,
                                    struct sk_buff *msg)
{
        struct virtio_blk_config config = {};
        u64 features_device;

        vdev->config->get_config(vdev, 0, &config, sizeof(config));

        features_device = vdev->config->get_device_features(vdev);

        if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_FEATURES, features_device,
                              VDPA_ATTR_PAD))
                return -EMSGSIZE;

        if (vdpa_dev_blk_capacity_config_fill(msg, &config))
                return -EMSGSIZE;

        if (vdpa_dev_blk_seg_size_config_fill(msg, features_device, &config))
                return -EMSGSIZE;

        if (vdpa_dev_blk_block_size_config_fill(msg, features_device, &config))
                return -EMSGSIZE;

        if (vdpa_dev_blk_seg_max_config_fill(msg, features_device, &config))
                return -EMSGSIZE;

        if (vdpa_dev_blk_mq_config_fill(msg, features_device, &config))
                return -EMSGSIZE;

        if (vdpa_dev_blk_topology_config_fill(msg, features_device, &config))
                return -EMSGSIZE;

        if (vdpa_dev_blk_discard_config_fill(msg, features_device, &config))
                return -EMSGSIZE;

        if (vdpa_dev_blk_write_zeroes_config_fill(msg, features_device, &config))
                return -EMSGSIZE;

        if (vdpa_dev_blk_ro_config_fill(msg, features_device))
                return -EMSGSIZE;

        if (vdpa_dev_blk_flush_config_fill(msg, features_device))
                return -EMSGSIZE;

        return 0;
}

static int
vdpa_dev_config_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq,
                     int flags, struct netlink_ext_ack *extack)
{
        u64 features_driver;
        u8 status = 0;
        u32 device_id;
        void *hdr;
        int err;

        down_read(&vdev->cf_lock);
        hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags,
                          VDPA_CMD_DEV_CONFIG_GET);
        if (!hdr) {
                err = -EMSGSIZE;
                goto out;
        }

        if (nla_put_string(msg, VDPA_ATTR_DEV_NAME, dev_name(&vdev->dev))) {
                err = -EMSGSIZE;
                goto msg_err;
        }

        device_id = vdev->config->get_device_id(vdev);
        if (nla_put_u32(msg, VDPA_ATTR_DEV_ID, device_id)) {
                err = -EMSGSIZE;
                goto msg_err;
        }

        /* only read driver features after the feature negotiation is done */
        status = vdev->config->get_status(vdev);
        if (status & VIRTIO_CONFIG_S_FEATURES_OK) {
                features_driver = vdev->config->get_driver_features(vdev);
                if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_NEGOTIATED_FEATURES, features_driver,
                                      VDPA_ATTR_PAD)) {
                        err = -EMSGSIZE;
                        goto msg_err;
                }
        }

        switch (device_id) {
        case VIRTIO_ID_NET:
                err = vdpa_dev_net_config_fill(vdev, msg);
                break;
        case VIRTIO_ID_BLOCK:
                err = vdpa_dev_blk_config_fill(vdev, msg);
                break;
        default:
                err = -EOPNOTSUPP;
                break;
        }
        if (err)
                goto msg_err;

        up_read(&vdev->cf_lock);
        genlmsg_end(msg, hdr);
        return 0;

msg_err:
        genlmsg_cancel(msg, hdr);
out:
        up_read(&vdev->cf_lock);
        return err;
}

static int vdpa_fill_stats_rec(struct vdpa_device *vdev, struct sk_buff *msg,
                               struct genl_info *info, u32 index)
{
        struct virtio_net_config config = {};
        u64 features;
        u8 status;
        int err;

        status = vdev->config->get_status(vdev);
        if (!(status & VIRTIO_CONFIG_S_FEATURES_OK)) {
                NL_SET_ERR_MSG_MOD(info->extack, "feature negotiation not complete");
                return -EAGAIN;
        }
        vdpa_get_config_unlocked(vdev, 0, &config, sizeof(config));

        features = vdev->config->get_driver_features(vdev);
        if (nla_put_u64_64bit(msg, VDPA_ATTR_DEV_NEGOTIATED_FEATURES,
                              features, VDPA_ATTR_PAD))
                return -EMSGSIZE;

        err = vdpa_dev_net_mq_config_fill(msg, features, &config);
        if (err)
                return err;

        if (nla_put_u32(msg, VDPA_ATTR_DEV_QUEUE_INDEX, index))
                return -EMSGSIZE;

        err = vdev->config->get_vendor_vq_stats(vdev, index, msg, info->extack);
        if (err)
                return err;

        return 0;
}

static int vendor_stats_fill(struct vdpa_device *vdev, struct sk_buff *msg,
                             struct genl_info *info, u32 index)
{
        int err;

        down_read(&vdev->cf_lock);
        if (!vdev->config->get_vendor_vq_stats) {
                err = -EOPNOTSUPP;
                goto out;
        }

        err = vdpa_fill_stats_rec(vdev, msg, info, index);
out:
        up_read(&vdev->cf_lock);
        return err;
}

static int vdpa_dev_vendor_stats_fill(struct vdpa_device *vdev,
                                      struct sk_buff *msg,
                                      struct genl_info *info, u32 index)
{
        u32 device_id;
        void *hdr;
        int err;
        u32 portid = info->snd_portid;
        u32 seq = info->snd_seq;
        u32 flags = 0;

        hdr = genlmsg_put(msg, portid, seq, &vdpa_nl_family, flags,
                          VDPA_CMD_DEV_VSTATS_GET);
        if (!hdr)
                return -EMSGSIZE;

        if (nla_put_string(msg, VDPA_ATTR_DEV_NAME, dev_name(&vdev->dev))) {
                err = -EMSGSIZE;
                goto undo_msg;
        }

        device_id = vdev->config->get_device_id(vdev);
        if (nla_put_u32(msg, VDPA_ATTR_DEV_ID, device_id)) {
                err = -EMSGSIZE;
                goto undo_msg;
        }

        switch (device_id) {
        case VIRTIO_ID_NET:
                if (index > VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX) {
                        NL_SET_ERR_MSG_MOD(info->extack, "queue index exceeds max value");
                        err = -ERANGE;
                        break;
                }

                err = vendor_stats_fill(vdev, msg, info, index);
                break;
        default:
                err = -EOPNOTSUPP;
                break;
        }
        genlmsg_end(msg, hdr);

        return err;

undo_msg:
        genlmsg_cancel(msg, hdr);
        return err;
}

static int vdpa_nl_cmd_dev_config_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;

        down_read(&vdpa_dev_lock);
        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 dev_err;
        }
        vdev = container_of(dev, struct vdpa_device, dev);
        if (!vdev->mdev) {
                NL_SET_ERR_MSG_MOD(info->extack, "unmanaged vdpa device");
                err = -EINVAL;
                goto mdev_err;
        }
        err = vdpa_dev_config_fill(vdev, msg, info->snd_portid, info->snd_seq,
                                   0, info->extack);
        if (!err)
                err = genlmsg_reply(msg, info);

mdev_err:
        put_device(dev);
dev_err:
        up_read(&vdpa_dev_lock);
        if (err)
                nlmsg_free(msg);
        return err;
}

static int vdpa_dev_net_device_attr_set(struct vdpa_device *vdev,
                                        struct genl_info *info)
{
        struct vdpa_dev_set_config set_config = {};
        struct vdpa_mgmt_dev *mdev = vdev->mdev;
        struct nlattr **nl_attrs = info->attrs;
        const u8 *macaddr;
        int err = -EOPNOTSUPP;

        down_write(&vdev->cf_lock);
        if (nl_attrs[VDPA_ATTR_DEV_NET_CFG_MACADDR]) {
                set_config.mask |= BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MACADDR);
                macaddr = nla_data(nl_attrs[VDPA_ATTR_DEV_NET_CFG_MACADDR]);

                if (is_valid_ether_addr(macaddr)) {
                        ether_addr_copy(set_config.net.mac, macaddr);
                        if (mdev->ops->dev_set_attr) {
                                err = mdev->ops->dev_set_attr(mdev, vdev,
                                                              &set_config);
                        } else {
                                NL_SET_ERR_MSG_FMT_MOD(info->extack,
                                                       "Operation not supported by the device.");
                        }
                } else {
                        NL_SET_ERR_MSG_FMT_MOD(info->extack,
                                               "Invalid MAC address");
                }
        }
        up_write(&vdev->cf_lock);
        return err;
}

static int vdpa_nl_cmd_dev_attr_set_doit(struct sk_buff *skb,
                                         struct genl_info *info)
{
        struct vdpa_device *vdev;
        struct device *dev;
        const char *name;
        u64 classes;
        int err = 0;

        if (!info->attrs[VDPA_ATTR_DEV_NAME])
                return -EINVAL;

        name = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);

        down_write(&vdpa_dev_lock);
        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, "unmanaged vdpa device");
                err = -EINVAL;
                goto mdev_err;
        }
        classes = vdpa_mgmtdev_get_classes(vdev->mdev, NULL);
        if (classes & BIT_ULL(VIRTIO_ID_NET)) {
                err = vdpa_dev_net_device_attr_set(vdev, info);
        } else {
                NL_SET_ERR_MSG_FMT_MOD(info->extack, "%s device not supported",
                                       name);
        }

mdev_err:
        put_device(dev);
dev_err:
        up_write(&vdpa_dev_lock);
        return err;
}

static int vdpa_dev_config_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_config_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_config_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;

        down_read(&vdpa_dev_lock);
        bus_for_each_dev(&vdpa_bus, NULL, &info, vdpa_dev_config_dump);
        up_read(&vdpa_dev_lock);
        cb->args[0] = info.idx;
        return msg->len;
}

static int vdpa_nl_cmd_dev_stats_get_doit(struct sk_buff *skb,
                                          struct genl_info *info)
{
        struct vdpa_device *vdev;
        struct sk_buff *msg;
        const char *devname;
        struct device *dev;
        u32 index;
        int err;

        if (!info->attrs[VDPA_ATTR_DEV_NAME])
                return -EINVAL;

        if (!info->attrs[VDPA_ATTR_DEV_QUEUE_INDEX])
                return -EINVAL;

        devname = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
        msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
        if (!msg)
                return -ENOMEM;

        index = nla_get_u32(info->attrs[VDPA_ATTR_DEV_QUEUE_INDEX]);
        down_read(&vdpa_dev_lock);
        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 dev_err;
        }
        vdev = container_of(dev, struct vdpa_device, dev);
        if (!vdev->mdev) {
                NL_SET_ERR_MSG_MOD(info->extack, "unmanaged vdpa device");
                err = -EINVAL;
                goto mdev_err;
        }
        err = vdpa_dev_vendor_stats_fill(vdev, msg, info, index);
        if (err)
                goto mdev_err;

        err = genlmsg_reply(msg, info);

        put_device(dev);
        up_read(&vdpa_dev_lock);

        return err;

mdev_err:
        put_device(dev);
dev_err:
        nlmsg_free(msg);
        up_read(&vdpa_dev_lock);
        return err;
}

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 },
        [VDPA_ATTR_DEV_NET_CFG_MACADDR] = NLA_POLICY_ETH_ADDR,
        [VDPA_ATTR_DEV_NET_CFG_MAX_VQP] = { .type = NLA_U16 },
        /* virtio spec 1.1 section 5.1.4.1 for valid MTU range */
        [VDPA_ATTR_DEV_NET_CFG_MTU] = NLA_POLICY_MIN(NLA_U16, 68),
        [VDPA_ATTR_DEV_QUEUE_INDEX] = { .type = NLA_U32 },
        [VDPA_ATTR_DEV_FEATURES] = { .type = NLA_U64 },
};

static const struct genl_ops vdpa_nl_ops[] = {
        {
                .cmd = VDPA_CMD_MGMTDEV_GET,
                .doit = vdpa_nl_cmd_mgmtdev_get_doit,
                .dumpit = vdpa_nl_cmd_mgmtdev_get_dumpit,
        },
        {
                .cmd = VDPA_CMD_DEV_NEW,
                .doit = vdpa_nl_cmd_dev_add_set_doit,
                .flags = GENL_ADMIN_PERM,
        },
        {
                .cmd = VDPA_CMD_DEV_DEL,
                .doit = vdpa_nl_cmd_dev_del_set_doit,
                .flags = GENL_ADMIN_PERM,
        },
        {
                .cmd = VDPA_CMD_DEV_GET,
                .doit = vdpa_nl_cmd_dev_get_doit,
                .dumpit = vdpa_nl_cmd_dev_get_dumpit,
        },
        {
                .cmd = VDPA_CMD_DEV_CONFIG_GET,
                .doit = vdpa_nl_cmd_dev_config_get_doit,
                .dumpit = vdpa_nl_cmd_dev_config_get_dumpit,
        },
        {
                .cmd = VDPA_CMD_DEV_VSTATS_GET,
                .doit = vdpa_nl_cmd_dev_stats_get_doit,
                .flags = GENL_ADMIN_PERM,
        },
        {
                .cmd = VDPA_CMD_DEV_ATTR_SET,
                .doit = vdpa_nl_cmd_dev_attr_set_doit,
                .flags = GENL_ADMIN_PERM,
        },
};

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),
        .resv_start_op = VDPA_CMD_DEV_VSTATS_GET + 1,
};

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_DESCRIPTION("vDPA bus");
MODULE_LICENSE("GPL v2");