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SubjectRe: [PATCH v8 09/10] vduse: Introduce VDUSE - vDPA Device in Userspace
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在 2021/6/15 下午10:13, Xie Yongji 写道:
> This VDUSE driver enables implementing vDPA devices in userspace.
> The vDPA device's control path is handled in kernel and the data
> path is handled in userspace.
>
> A message mechnism is used by VDUSE driver to forward some control
> messages such as starting/stopping datapath to userspace. Userspace
> can use read()/write() to receive/reply those control messages.
>
> And some ioctls are introduced to help userspace to implement the
> data path. VDUSE_IOTLB_GET_FD ioctl can be used to get the file
> descriptors referring to vDPA device's iova regions. Then userspace
> can use mmap() to access those iova regions. VDUSE_DEV_GET_FEATURES
> and VDUSE_VQ_GET_INFO ioctls are used to get the negotiated features
> and metadata of virtqueues. VDUSE_INJECT_VQ_IRQ and VDUSE_VQ_SETUP_KICKFD
> ioctls can be used to inject interrupt and setup the kickfd for
> virtqueues. VDUSE_DEV_UPDATE_CONFIG ioctl is used to update the
> configuration space and inject a config interrupt.
>
> Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
> ---
> Documentation/userspace-api/ioctl/ioctl-number.rst | 1 +
> drivers/vdpa/Kconfig | 10 +
> drivers/vdpa/Makefile | 1 +
> drivers/vdpa/vdpa_user/Makefile | 5 +
> drivers/vdpa/vdpa_user/vduse_dev.c | 1453 ++++++++++++++++++++
> include/uapi/linux/vduse.h | 143 ++
> 6 files changed, 1613 insertions(+)
> create mode 100644 drivers/vdpa/vdpa_user/Makefile
> create mode 100644 drivers/vdpa/vdpa_user/vduse_dev.c
> create mode 100644 include/uapi/linux/vduse.h
>
> diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
> index 9bfc2b510c64..acd95e9dcfe7 100644
> --- a/Documentation/userspace-api/ioctl/ioctl-number.rst
> +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
> @@ -300,6 +300,7 @@ Code Seq# Include File Comments
> 'z' 10-4F drivers/s390/crypto/zcrypt_api.h conflict!
> '|' 00-7F linux/media.h
> 0x80 00-1F linux/fb.h
> +0x81 00-1F linux/vduse.h
> 0x89 00-06 arch/x86/include/asm/sockios.h
> 0x89 0B-DF linux/sockios.h
> 0x89 E0-EF linux/sockios.h SIOCPROTOPRIVATE range
> diff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig
> index a503c1b2bfd9..6e23bce6433a 100644
> --- a/drivers/vdpa/Kconfig
> +++ b/drivers/vdpa/Kconfig
> @@ -33,6 +33,16 @@ config VDPA_SIM_BLOCK
> vDPA block device simulator which terminates IO request in a
> memory buffer.
>
> +config VDPA_USER
> + tristate "VDUSE (vDPA Device in Userspace) support"
> + depends on EVENTFD && MMU && HAS_DMA
> + select DMA_OPS
> + select VHOST_IOTLB
> + select IOMMU_IOVA
> + help
> + With VDUSE it is possible to emulate a vDPA Device
> + in a userspace program.
> +
> config IFCVF
> tristate "Intel IFC VF vDPA driver"
> depends on PCI_MSI
> diff --git a/drivers/vdpa/Makefile b/drivers/vdpa/Makefile
> index 67fe7f3d6943..f02ebed33f19 100644
> --- a/drivers/vdpa/Makefile
> +++ b/drivers/vdpa/Makefile
> @@ -1,6 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0
> obj-$(CONFIG_VDPA) += vdpa.o
> obj-$(CONFIG_VDPA_SIM) += vdpa_sim/
> +obj-$(CONFIG_VDPA_USER) += vdpa_user/
> obj-$(CONFIG_IFCVF) += ifcvf/
> obj-$(CONFIG_MLX5_VDPA) += mlx5/
> obj-$(CONFIG_VP_VDPA) += virtio_pci/
> diff --git a/drivers/vdpa/vdpa_user/Makefile b/drivers/vdpa/vdpa_user/Makefile
> new file mode 100644
> index 000000000000..260e0b26af99
> --- /dev/null
> +++ b/drivers/vdpa/vdpa_user/Makefile
> @@ -0,0 +1,5 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +vduse-y := vduse_dev.o iova_domain.o
> +
> +obj-$(CONFIG_VDPA_USER) += vduse.o
> diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
> new file mode 100644
> index 000000000000..5271cbd15e28
> --- /dev/null
> +++ b/drivers/vdpa/vdpa_user/vduse_dev.c
> @@ -0,0 +1,1453 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * VDUSE: vDPA Device in Userspace
> + *
> + * Copyright (C) 2020-2021 Bytedance Inc. and/or its affiliates. All rights reserved.
> + *
> + * Author: Xie Yongji <xieyongji@bytedance.com>
> + *
> + */
> +
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/cdev.h>
> +#include <linux/device.h>
> +#include <linux/eventfd.h>
> +#include <linux/slab.h>
> +#include <linux/wait.h>
> +#include <linux/dma-map-ops.h>
> +#include <linux/poll.h>
> +#include <linux/file.h>
> +#include <linux/uio.h>
> +#include <linux/vdpa.h>
> +#include <linux/nospec.h>
> +#include <uapi/linux/vduse.h>
> +#include <uapi/linux/vdpa.h>
> +#include <uapi/linux/virtio_config.h>
> +#include <uapi/linux/virtio_ids.h>
> +#include <uapi/linux/virtio_blk.h>
> +#include <linux/mod_devicetable.h>
> +
> +#include "iova_domain.h"
> +
> +#define DRV_AUTHOR "Yongji Xie <xieyongji@bytedance.com>"
> +#define DRV_DESC "vDPA Device in Userspace"
> +#define DRV_LICENSE "GPL v2"
> +
> +#define VDUSE_DEV_MAX (1U << MINORBITS)
> +#define VDUSE_MAX_BOUNCE_SIZE (64 * 1024 * 1024)
> +#define VDUSE_IOVA_SIZE (128 * 1024 * 1024)
> +#define VDUSE_REQUEST_TIMEOUT 30
> +
> +struct vduse_virtqueue {
> + u16 index;
> + u32 num;
> + u32 avail_idx;
> + u64 desc_addr;
> + u64 driver_addr;
> + u64 device_addr;
> + bool ready;
> + bool kicked;
> + spinlock_t kick_lock;
> + spinlock_t irq_lock;
> + struct eventfd_ctx *kickfd;
> + struct vdpa_callback cb;
> + struct work_struct inject;
> +};
> +
> +struct vduse_dev;
> +
> +struct vduse_vdpa {
> + struct vdpa_device vdpa;
> + struct vduse_dev *dev;
> +};
> +
> +struct vduse_dev {
> + struct vduse_vdpa *vdev;
> + struct device *dev;
> + struct vduse_virtqueue *vqs;
> + struct vduse_iova_domain *domain;
> + char *name;
> + struct mutex lock;
> + spinlock_t msg_lock;
> + u64 msg_unique;
> + wait_queue_head_t waitq;
> + struct list_head send_list;
> + struct list_head recv_list;
> + struct vdpa_callback config_cb;
> + struct work_struct inject;
> + spinlock_t irq_lock;
> + int minor;
> + bool connected;
> + bool started;
> + u64 api_version;
> + u64 user_features;


Let's use device_features.


> + u64 features;


And driver features.


> + u32 device_id;
> + u32 vendor_id;
> + u32 generation;
> + u32 config_size;
> + void *config;
> + u8 status;
> + u16 vq_size_max;
> + u32 vq_num;
> + u32 vq_align;
> +};
> +
> +struct vduse_dev_msg {
> + struct vduse_dev_request req;
> + struct vduse_dev_response resp;
> + struct list_head list;
> + wait_queue_head_t waitq;
> + bool completed;
> +};
> +
> +struct vduse_control {
> + u64 api_version;
> +};
> +
> +static DEFINE_MUTEX(vduse_lock);
> +static DEFINE_IDR(vduse_idr);
> +
> +static dev_t vduse_major;
> +static struct class *vduse_class;
> +static struct cdev vduse_ctrl_cdev;
> +static struct cdev vduse_cdev;
> +static struct workqueue_struct *vduse_irq_wq;
> +
> +static u32 allowed_device_id[] = {
> + VIRTIO_ID_BLOCK,
> +};
> +
> +static inline struct vduse_dev *vdpa_to_vduse(struct vdpa_device *vdpa)
> +{
> + struct vduse_vdpa *vdev = container_of(vdpa, struct vduse_vdpa, vdpa);
> +
> + return vdev->dev;
> +}
> +
> +static inline struct vduse_dev *dev_to_vduse(struct device *dev)
> +{
> + struct vdpa_device *vdpa = dev_to_vdpa(dev);
> +
> + return vdpa_to_vduse(vdpa);
> +}
> +
> +static struct vduse_dev_msg *vduse_find_msg(struct list_head *head,
> + uint32_t request_id)
> +{
> + struct vduse_dev_msg *msg;
> +
> + list_for_each_entry(msg, head, list) {
> + if (msg->req.request_id == request_id) {
> + list_del(&msg->list);
> + return msg;
> + }
> + }
> +
> + return NULL;
> +}
> +
> +static struct vduse_dev_msg *vduse_dequeue_msg(struct list_head *head)
> +{
> + struct vduse_dev_msg *msg = NULL;
> +
> + if (!list_empty(head)) {
> + msg = list_first_entry(head, struct vduse_dev_msg, list);
> + list_del(&msg->list);
> + }
> +
> + return msg;
> +}
> +
> +static void vduse_enqueue_msg(struct list_head *head,
> + struct vduse_dev_msg *msg)
> +{
> + list_add_tail(&msg->list, head);
> +}
> +
> +static int vduse_dev_msg_send(struct vduse_dev *dev,
> + struct vduse_dev_msg *msg, bool no_reply)
> +{


It looks to me the only user for no_reply=true is the dataplane start. I
wonder no_reply is really needed consider we have switched to use
wait_event_killable_timeout().

In another way, no_reply is false for vq state synchronization and IOTLB
updating. I wonder if we can simply use no_reply = true for them.


> + init_waitqueue_head(&msg->waitq);
> + spin_lock(&dev->msg_lock);
> + msg->req.request_id = dev->msg_unique++;
> + vduse_enqueue_msg(&dev->send_list, msg);
> + wake_up(&dev->waitq);
> + spin_unlock(&dev->msg_lock);
> + if (no_reply)
> + return 0;
> +
> + wait_event_killable_timeout(msg->waitq, msg->completed,
> + VDUSE_REQUEST_TIMEOUT * HZ);
> + spin_lock(&dev->msg_lock);
> + if (!msg->completed) {
> + list_del(&msg->list);
> + msg->resp.result = VDUSE_REQ_RESULT_FAILED;
> + }
> + spin_unlock(&dev->msg_lock);
> +
> + return (msg->resp.result == VDUSE_REQ_RESULT_OK) ? 0 : -EIO;


Do we need to serialize the check by protecting it with the spinlock above?


> +}
> +
> +static void vduse_dev_msg_cleanup(struct vduse_dev *dev)
> +{
> + struct vduse_dev_msg *msg;
> +
> + spin_lock(&dev->msg_lock);
> + while ((msg = vduse_dequeue_msg(&dev->send_list))) {
> + if (msg->req.flags & VDUSE_REQ_FLAGS_NO_REPLY)
> + kfree(msg);
> + else
> + vduse_enqueue_msg(&dev->recv_list, msg);
> + }
> + while ((msg = vduse_dequeue_msg(&dev->recv_list))) {
> + msg->resp.result = VDUSE_REQ_RESULT_FAILED;
> + msg->completed = 1;
> + wake_up(&msg->waitq);
> + }
> + spin_unlock(&dev->msg_lock);
> +}
> +
> +static void vduse_dev_start_dataplane(struct vduse_dev *dev)
> +{
> + struct vduse_dev_msg *msg = kzalloc(sizeof(*msg),
> + GFP_KERNEL | __GFP_NOFAIL);
> +
> + msg->req.type = VDUSE_START_DATAPLANE;
> + msg->req.flags |= VDUSE_REQ_FLAGS_NO_REPLY;
> + vduse_dev_msg_send(dev, msg, true);
> +}
> +
> +static void vduse_dev_stop_dataplane(struct vduse_dev *dev)
> +{
> + struct vduse_dev_msg *msg = kzalloc(sizeof(*msg),
> + GFP_KERNEL | __GFP_NOFAIL);
> +
> + msg->req.type = VDUSE_STOP_DATAPLANE;
> + msg->req.flags |= VDUSE_REQ_FLAGS_NO_REPLY;


Can we simply use this flag instead of introducing a new parameter
(no_reply) in vduse_dev_msg_send()?


> + vduse_dev_msg_send(dev, msg, true);
> +}
> +
> +static int vduse_dev_get_vq_state(struct vduse_dev *dev,
> + struct vduse_virtqueue *vq,
> + struct vdpa_vq_state *state)
> +{
> + struct vduse_dev_msg msg = { 0 };
> + int ret;


Note that I post a series that implement the packed virtqueue support:

https://lists.linuxfoundation.org/pipermail/virtualization/2021-June/054501.html

So this patch needs to be updated as well.


> +
> + msg.req.type = VDUSE_GET_VQ_STATE;
> + msg.req.vq_state.index = vq->index;
> +
> + ret = vduse_dev_msg_send(dev, &msg, false);
> + if (ret)
> + return ret;
> +
> + state->avail_index = msg.resp.vq_state.avail_idx;
> + return 0;
> +}
> +
> +static int vduse_dev_update_iotlb(struct vduse_dev *dev,
> + u64 start, u64 last)
> +{
> + struct vduse_dev_msg msg = { 0 };
> +
> + if (last < start)
> + return -EINVAL;
> +
> + msg.req.type = VDUSE_UPDATE_IOTLB;
> + msg.req.iova.start = start;
> + msg.req.iova.last = last;
> +
> + return vduse_dev_msg_send(dev, &msg, false);
> +}
> +
> +static ssize_t vduse_dev_read_iter(struct kiocb *iocb, struct iov_iter *to)
> +{
> + struct file *file = iocb->ki_filp;
> + struct vduse_dev *dev = file->private_data;
> + struct vduse_dev_msg *msg;
> + int size = sizeof(struct vduse_dev_request);
> + ssize_t ret;
> +
> + if (iov_iter_count(to) < size)
> + return -EINVAL;
> +
> + spin_lock(&dev->msg_lock);
> + while (1) {
> + msg = vduse_dequeue_msg(&dev->send_list);
> + if (msg)
> + break;
> +
> + ret = -EAGAIN;
> + if (file->f_flags & O_NONBLOCK)
> + goto unlock;
> +
> + spin_unlock(&dev->msg_lock);
> + ret = wait_event_interruptible_exclusive(dev->waitq,
> + !list_empty(&dev->send_list));
> + if (ret)
> + return ret;
> +
> + spin_lock(&dev->msg_lock);
> + }
> + spin_unlock(&dev->msg_lock);
> + ret = copy_to_iter(&msg->req, size, to);
> + spin_lock(&dev->msg_lock);
> + if (ret != size) {
> + ret = -EFAULT;
> + vduse_enqueue_msg(&dev->send_list, msg);
> + goto unlock;
> + }
> + if (msg->req.flags & VDUSE_REQ_FLAGS_NO_REPLY)
> + kfree(msg);
> + else
> + vduse_enqueue_msg(&dev->recv_list, msg);
> +unlock:
> + spin_unlock(&dev->msg_lock);
> +
> + return ret;
> +}
> +
> +static ssize_t vduse_dev_write_iter(struct kiocb *iocb, struct iov_iter *from)
> +{
> + struct file *file = iocb->ki_filp;
> + struct vduse_dev *dev = file->private_data;
> + struct vduse_dev_response resp;
> + struct vduse_dev_msg *msg;
> + size_t ret;
> +
> + ret = copy_from_iter(&resp, sizeof(resp), from);
> + if (ret != sizeof(resp))
> + return -EINVAL;
> +
> + spin_lock(&dev->msg_lock);
> + msg = vduse_find_msg(&dev->recv_list, resp.request_id);
> + if (!msg) {
> + ret = -ENOENT;
> + goto unlock;
> + }
> +
> + memcpy(&msg->resp, &resp, sizeof(resp));
> + msg->completed = 1;
> + wake_up(&msg->waitq);
> +unlock:
> + spin_unlock(&dev->msg_lock);
> +
> + return ret;
> +}
> +
> +static __poll_t vduse_dev_poll(struct file *file, poll_table *wait)
> +{
> + struct vduse_dev *dev = file->private_data;
> + __poll_t mask = 0;
> +
> + poll_wait(file, &dev->waitq, wait);
> +
> + if (!list_empty(&dev->send_list))
> + mask |= EPOLLIN | EPOLLRDNORM;
> + if (!list_empty(&dev->recv_list))
> + mask |= EPOLLOUT | EPOLLWRNORM;
> +
> + return mask;
> +}
> +
> +static void vduse_dev_reset(struct vduse_dev *dev)
> +{
> + int i;
> + struct vduse_iova_domain *domain = dev->domain;
> +
> + /* The coherent mappings are handled in vduse_dev_free_coherent() */
> + if (domain->bounce_map)
> + vduse_domain_reset_bounce_map(domain);
> +
> + dev->features = 0;
> + dev->generation++;
> + spin_lock(&dev->irq_lock);
> + dev->config_cb.callback = NULL;
> + dev->config_cb.private = NULL;
> + spin_unlock(&dev->irq_lock);
> +
> + for (i = 0; i < dev->vq_num; i++) {
> + struct vduse_virtqueue *vq = &dev->vqs[i];
> +
> + vq->ready = false;
> + vq->desc_addr = 0;
> + vq->driver_addr = 0;
> + vq->device_addr = 0;
> + vq->avail_idx = 0;
> + vq->num = 0;
> +
> + spin_lock(&vq->kick_lock);
> + vq->kicked = false;
> + if (vq->kickfd)
> + eventfd_ctx_put(vq->kickfd);
> + vq->kickfd = NULL;
> + spin_unlock(&vq->kick_lock);
> +
> + spin_lock(&vq->irq_lock);
> + vq->cb.callback = NULL;
> + vq->cb.private = NULL;
> + spin_unlock(&vq->irq_lock);
> + }
> +}
> +
> +static int vduse_vdpa_set_vq_address(struct vdpa_device *vdpa, u16 idx,
> + u64 desc_area, u64 driver_area,
> + u64 device_area)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> + struct vduse_virtqueue *vq = &dev->vqs[idx];
> +
> + vq->desc_addr = desc_area;
> + vq->driver_addr = driver_area;
> + vq->device_addr = device_area;
> +
> + return 0;
> +}
> +
> +static void vduse_vdpa_kick_vq(struct vdpa_device *vdpa, u16 idx)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> + struct vduse_virtqueue *vq = &dev->vqs[idx];
> +
> + spin_lock(&vq->kick_lock);
> + if (!vq->ready)
> + goto unlock;
> +
> + if (vq->kickfd)
> + eventfd_signal(vq->kickfd, 1);
> + else
> + vq->kicked = true;
> +unlock:
> + spin_unlock(&vq->kick_lock);
> +}
> +
> +static void vduse_vdpa_set_vq_cb(struct vdpa_device *vdpa, u16 idx,
> + struct vdpa_callback *cb)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> + struct vduse_virtqueue *vq = &dev->vqs[idx];
> +
> + spin_lock(&vq->irq_lock);
> + vq->cb.callback = cb->callback;
> + vq->cb.private = cb->private;
> + spin_unlock(&vq->irq_lock);
> +}
> +
> +static void vduse_vdpa_set_vq_num(struct vdpa_device *vdpa, u16 idx, u32 num)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> + struct vduse_virtqueue *vq = &dev->vqs[idx];
> +
> + vq->num = num;
> +}
> +
> +static void vduse_vdpa_set_vq_ready(struct vdpa_device *vdpa,
> + u16 idx, bool ready)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> + struct vduse_virtqueue *vq = &dev->vqs[idx];
> +
> + vq->ready = ready;
> +}
> +
> +static bool vduse_vdpa_get_vq_ready(struct vdpa_device *vdpa, u16 idx)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> + struct vduse_virtqueue *vq = &dev->vqs[idx];
> +
> + return vq->ready;
> +}
> +
> +static int vduse_vdpa_set_vq_state(struct vdpa_device *vdpa, u16 idx,
> + const struct vdpa_vq_state *state)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> + struct vduse_virtqueue *vq = &dev->vqs[idx];
> +
> + vq->avail_idx = state->avail_index;
> + return 0;
> +}
> +
> +static int vduse_vdpa_get_vq_state(struct vdpa_device *vdpa, u16 idx,
> + struct vdpa_vq_state *state)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> + struct vduse_virtqueue *vq = &dev->vqs[idx];
> +
> + return vduse_dev_get_vq_state(dev, vq, state);
> +}
> +
> +static u32 vduse_vdpa_get_vq_align(struct vdpa_device *vdpa)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> +
> + return dev->vq_align;
> +}
> +
> +static u64 vduse_vdpa_get_features(struct vdpa_device *vdpa)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> +
> + return dev->user_features;
> +}
> +
> +static int vduse_vdpa_set_features(struct vdpa_device *vdpa, u64 features)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> +
> + dev->features = features;
> + return 0;
> +}
> +
> +static void vduse_vdpa_set_config_cb(struct vdpa_device *vdpa,
> + struct vdpa_callback *cb)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> +
> + spin_lock(&dev->irq_lock);
> + dev->config_cb.callback = cb->callback;
> + dev->config_cb.private = cb->private;
> + spin_unlock(&dev->irq_lock);
> +}
> +
> +static u16 vduse_vdpa_get_vq_num_max(struct vdpa_device *vdpa)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> +
> + return dev->vq_size_max;
> +}
> +
> +static u32 vduse_vdpa_get_device_id(struct vdpa_device *vdpa)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> +
> + return dev->device_id;
> +}
> +
> +static u32 vduse_vdpa_get_vendor_id(struct vdpa_device *vdpa)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> +
> + return dev->vendor_id;
> +}
> +
> +static u8 vduse_vdpa_get_status(struct vdpa_device *vdpa)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> +
> + return dev->status;
> +}
> +
> +static void vduse_vdpa_set_status(struct vdpa_device *vdpa, u8 status)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> + bool started = !!(status & VIRTIO_CONFIG_S_DRIVER_OK);
> +
> + dev->status = status;
> +
> + if (dev->started == started)
> + return;


If we check dev->status == status, (or only check the DRIVER_OK bit)
then there's no need to introduce an extra dev->started.


> +
> + dev->started = started;
> + if (dev->started) {
> + vduse_dev_start_dataplane(dev);
> + } else {
> + vduse_dev_reset(dev);
> + vduse_dev_stop_dataplane(dev);


I wonder if no_reply work for the case of vhost-vdpa. For virtio-vDPA,
we have bouncing buffers so it's harmless if usersapce dataplane keeps
performing read/write. For vhost-vDPA we don't have such stuffs.


> + }
> +}
> +
> +static size_t vduse_vdpa_get_config_size(struct vdpa_device *vdpa)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> +
> + return dev->config_size;
> +}
> +
> +static void vduse_vdpa_get_config(struct vdpa_device *vdpa, unsigned int offset,
> + void *buf, unsigned int len)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> +
> + memcpy(buf, dev->config + offset, len);
> +}
> +
> +static void vduse_vdpa_set_config(struct vdpa_device *vdpa, unsigned int offset,
> + const void *buf, unsigned int len)
> +{
> + /* Now we only support read-only configuration space */
> +}
> +
> +static u32 vduse_vdpa_get_generation(struct vdpa_device *vdpa)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> +
> + return dev->generation;
> +}
> +
> +static int vduse_vdpa_set_map(struct vdpa_device *vdpa,
> + struct vhost_iotlb *iotlb)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> + int ret;
> +
> + ret = vduse_domain_set_map(dev->domain, iotlb);
> + if (ret)
> + return ret;
> +
> + ret = vduse_dev_update_iotlb(dev, 0ULL, ULLONG_MAX);
> + if (ret) {
> + vduse_domain_clear_map(dev->domain, iotlb);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static void vduse_vdpa_free(struct vdpa_device *vdpa)
> +{
> + struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> +
> + dev->vdev = NULL;
> +}
> +
> +static const struct vdpa_config_ops vduse_vdpa_config_ops = {
> + .set_vq_address = vduse_vdpa_set_vq_address,
> + .kick_vq = vduse_vdpa_kick_vq,
> + .set_vq_cb = vduse_vdpa_set_vq_cb,
> + .set_vq_num = vduse_vdpa_set_vq_num,
> + .set_vq_ready = vduse_vdpa_set_vq_ready,
> + .get_vq_ready = vduse_vdpa_get_vq_ready,
> + .set_vq_state = vduse_vdpa_set_vq_state,
> + .get_vq_state = vduse_vdpa_get_vq_state,
> + .get_vq_align = vduse_vdpa_get_vq_align,
> + .get_features = vduse_vdpa_get_features,
> + .set_features = vduse_vdpa_set_features,
> + .set_config_cb = vduse_vdpa_set_config_cb,
> + .get_vq_num_max = vduse_vdpa_get_vq_num_max,
> + .get_device_id = vduse_vdpa_get_device_id,
> + .get_vendor_id = vduse_vdpa_get_vendor_id,
> + .get_status = vduse_vdpa_get_status,
> + .set_status = vduse_vdpa_set_status,
> + .get_config_size = vduse_vdpa_get_config_size,
> + .get_config = vduse_vdpa_get_config,
> + .set_config = vduse_vdpa_set_config,
> + .get_generation = vduse_vdpa_get_generation,
> + .set_map = vduse_vdpa_set_map,
> + .free = vduse_vdpa_free,
> +};
> +
> +static dma_addr_t vduse_dev_map_page(struct device *dev, struct page *page,
> + unsigned long offset, size_t size,
> + enum dma_data_direction dir,
> + unsigned long attrs)
> +{
> + struct vduse_dev *vdev = dev_to_vduse(dev);
> + struct vduse_iova_domain *domain = vdev->domain;
> +
> + return vduse_domain_map_page(domain, page, offset, size, dir, attrs);
> +}
> +
> +static void vduse_dev_unmap_page(struct device *dev, dma_addr_t dma_addr,
> + size_t size, enum dma_data_direction dir,
> + unsigned long attrs)
> +{
> + struct vduse_dev *vdev = dev_to_vduse(dev);
> + struct vduse_iova_domain *domain = vdev->domain;
> +
> + return vduse_domain_unmap_page(domain, dma_addr, size, dir, attrs);
> +}
> +
> +static void *vduse_dev_alloc_coherent(struct device *dev, size_t size,
> + dma_addr_t *dma_addr, gfp_t flag,
> + unsigned long attrs)
> +{
> + struct vduse_dev *vdev = dev_to_vduse(dev);
> + struct vduse_iova_domain *domain = vdev->domain;
> + unsigned long iova;
> + void *addr;
> +
> + *dma_addr = DMA_MAPPING_ERROR;
> + addr = vduse_domain_alloc_coherent(domain, size,
> + (dma_addr_t *)&iova, flag, attrs);
> + if (!addr)
> + return NULL;
> +
> + *dma_addr = (dma_addr_t)iova;
> +
> + return addr;
> +}
> +
> +static void vduse_dev_free_coherent(struct device *dev, size_t size,
> + void *vaddr, dma_addr_t dma_addr,
> + unsigned long attrs)
> +{
> + struct vduse_dev *vdev = dev_to_vduse(dev);
> + struct vduse_iova_domain *domain = vdev->domain;
> +
> + vduse_domain_free_coherent(domain, size, vaddr, dma_addr, attrs);
> +}
> +
> +static size_t vduse_dev_max_mapping_size(struct device *dev)
> +{
> + struct vduse_dev *vdev = dev_to_vduse(dev);
> + struct vduse_iova_domain *domain = vdev->domain;
> +
> + return domain->bounce_size;
> +}
> +
> +static const struct dma_map_ops vduse_dev_dma_ops = {
> + .map_page = vduse_dev_map_page,
> + .unmap_page = vduse_dev_unmap_page,
> + .alloc = vduse_dev_alloc_coherent,
> + .free = vduse_dev_free_coherent,
> + .max_mapping_size = vduse_dev_max_mapping_size,
> +};
> +
> +static unsigned int perm_to_file_flags(u8 perm)
> +{
> + unsigned int flags = 0;
> +
> + switch (perm) {
> + case VDUSE_ACCESS_WO:
> + flags |= O_WRONLY;
> + break;
> + case VDUSE_ACCESS_RO:
> + flags |= O_RDONLY;
> + break;
> + case VDUSE_ACCESS_RW:
> + flags |= O_RDWR;
> + break;
> + default:
> + WARN(1, "invalidate vhost IOTLB permission\n");
> + break;
> + }
> +
> + return flags;
> +}
> +
> +static int vduse_kickfd_setup(struct vduse_dev *dev,
> + struct vduse_vq_eventfd *eventfd)
> +{
> + struct eventfd_ctx *ctx = NULL;
> + struct vduse_virtqueue *vq;
> + u32 index;
> +
> + if (eventfd->index >= dev->vq_num)
> + return -EINVAL;
> +
> + index = array_index_nospec(eventfd->index, dev->vq_num);
> + vq = &dev->vqs[index];
> + if (eventfd->fd >= 0) {
> + ctx = eventfd_ctx_fdget(eventfd->fd);
> + if (IS_ERR(ctx))
> + return PTR_ERR(ctx);
> + } else if (eventfd->fd != VDUSE_EVENTFD_DEASSIGN)
> + return 0;
> +
> + spin_lock(&vq->kick_lock);
> + if (vq->kickfd)
> + eventfd_ctx_put(vq->kickfd);
> + vq->kickfd = ctx;
> + if (vq->ready && vq->kicked && vq->kickfd) {
> + eventfd_signal(vq->kickfd, 1);
> + vq->kicked = false;
> + }
> + spin_unlock(&vq->kick_lock);
> +
> + return 0;
> +}
> +
> +static void vduse_dev_irq_inject(struct work_struct *work)
> +{
> + struct vduse_dev *dev = container_of(work, struct vduse_dev, inject);
> +
> + spin_lock_irq(&dev->irq_lock);
> + if (dev->config_cb.callback)
> + dev->config_cb.callback(dev->config_cb.private);
> + spin_unlock_irq(&dev->irq_lock);
> +}
> +
> +static void vduse_vq_irq_inject(struct work_struct *work)
> +{
> + struct vduse_virtqueue *vq = container_of(work,
> + struct vduse_virtqueue, inject);
> +
> + spin_lock_irq(&vq->irq_lock);
> + if (vq->ready && vq->cb.callback)
> + vq->cb.callback(vq->cb.private);
> + spin_unlock_irq(&vq->irq_lock);
> +}
> +
> +static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
> + unsigned long arg)
> +{
> + struct vduse_dev *dev = file->private_data;
> + void __user *argp = (void __user *)arg;
> + int ret;
> +
> + switch (cmd) {
> + case VDUSE_IOTLB_GET_FD: {
> + struct vduse_iotlb_entry entry;
> + struct vhost_iotlb_map *map;
> + struct vdpa_map_file *map_file;
> + struct vduse_iova_domain *domain = dev->domain;
> + struct file *f = NULL;
> +
> + ret = -EFAULT;
> + if (copy_from_user(&entry, argp, sizeof(entry)))
> + break;
> +
> + ret = -EINVAL;
> + if (entry.start > entry.last)
> + break;
> +
> + spin_lock(&domain->iotlb_lock);
> + map = vhost_iotlb_itree_first(domain->iotlb,
> + entry.start, entry.last);
> + if (map) {
> + map_file = (struct vdpa_map_file *)map->opaque;
> + f = get_file(map_file->file);
> + entry.offset = map_file->offset;
> + entry.start = map->start;
> + entry.last = map->last;
> + entry.perm = map->perm;
> + }
> + spin_unlock(&domain->iotlb_lock);
> + ret = -EINVAL;
> + if (!f)
> + break;
> +
> + ret = -EFAULT;
> + if (copy_to_user(argp, &entry, sizeof(entry))) {
> + fput(f);
> + break;
> + }
> + ret = receive_fd(f, perm_to_file_flags(entry.perm));
> + fput(f);
> + break;
> + }
> + case VDUSE_DEV_GET_FEATURES:
> + ret = put_user(dev->features, (u64 __user *)argp);
> + break;
> + case VDUSE_DEV_UPDATE_CONFIG: {
> + struct vduse_config_update config;
> + unsigned long size = offsetof(struct vduse_config_update,
> + buffer);
> +
> + ret = -EFAULT;
> + if (copy_from_user(&config, argp, size))
> + break;
> +
> + ret = -EINVAL;
> + if (config.length == 0 ||
> + config.length > dev->config_size - config.offset)
> + break;
> +
> + ret = -EFAULT;
> + if (copy_from_user(dev->config + config.offset, argp + size,
> + config.length))
> + break;
> +
> + ret = 0;
> + queue_work(vduse_irq_wq, &dev->inject);


I wonder if it's better to separate config interrupt out of config
update or we need document this.


> + break;
> + }
> + case VDUSE_VQ_GET_INFO: {


Do we need to limit this only when DRIVER_OK is set?


> + struct vduse_vq_info vq_info;
> + u32 vq_index;
> +
> + ret = -EFAULT;
> + if (copy_from_user(&vq_info, argp, sizeof(vq_info)))
> + break;
> +
> + ret = -EINVAL;
> + if (vq_info.index >= dev->vq_num)
> + break;
> +
> + vq_index = array_index_nospec(vq_info.index, dev->vq_num);
> + vq_info.desc_addr = dev->vqs[vq_index].desc_addr;
> + vq_info.driver_addr = dev->vqs[vq_index].driver_addr;
> + vq_info.device_addr = dev->vqs[vq_index].device_addr;
> + vq_info.num = dev->vqs[vq_index].num;
> + vq_info.avail_idx = dev->vqs[vq_index].avail_idx;
> + vq_info.ready = dev->vqs[vq_index].ready;
> +
> + ret = -EFAULT;
> + if (copy_to_user(argp, &vq_info, sizeof(vq_info)))
> + break;
> +
> + ret = 0;
> + break;
> + }
> + case VDUSE_VQ_SETUP_KICKFD: {
> + struct vduse_vq_eventfd eventfd;
> +
> + ret = -EFAULT;
> + if (copy_from_user(&eventfd, argp, sizeof(eventfd)))
> + break;
> +
> + ret = vduse_kickfd_setup(dev, &eventfd);
> + break;
> + }
> + case VDUSE_VQ_INJECT_IRQ: {
> + u32 vq_index;
> +
> + ret = -EFAULT;
> + if (get_user(vq_index, (u32 __user *)argp))
> + break;
> +
> + ret = -EINVAL;
> + if (vq_index >= dev->vq_num)
> + break;
> +
> + ret = 0;
> + vq_index = array_index_nospec(vq_index, dev->vq_num);
> + queue_work(vduse_irq_wq, &dev->vqs[vq_index].inject);
> + break;
> + }
> + default:
> + ret = -ENOIOCTLCMD;
> + break;
> + }
> +
> + return ret;
> +}
> +
> +static int vduse_dev_release(struct inode *inode, struct file *file)
> +{
> + struct vduse_dev *dev = file->private_data;
> +
> + spin_lock(&dev->msg_lock);
> + /* Make sure the inflight messages can processed after reconncection */
> + list_splice_init(&dev->recv_list, &dev->send_list);
> + spin_unlock(&dev->msg_lock);
> + dev->connected = false;
> +
> + return 0;
> +}
> +
> +static struct vduse_dev *vduse_dev_get_from_minor(int minor)
> +{
> + struct vduse_dev *dev;
> +
> + mutex_lock(&vduse_lock);
> + dev = idr_find(&vduse_idr, minor);
> + mutex_unlock(&vduse_lock);
> +
> + return dev;
> +}
> +
> +static int vduse_dev_open(struct inode *inode, struct file *file)
> +{
> + int ret;
> + struct vduse_dev *dev = vduse_dev_get_from_minor(iminor(inode));
> +
> + if (!dev)
> + return -ENODEV;
> +
> + ret = -EBUSY;
> + mutex_lock(&dev->lock);
> + if (dev->connected)
> + goto unlock;
> +
> + ret = 0;
> + dev->connected = true;
> + file->private_data = dev;
> +unlock:
> + mutex_unlock(&dev->lock);
> +
> + return ret;
> +}
> +
> +static const struct file_operations vduse_dev_fops = {
> + .owner = THIS_MODULE,
> + .open = vduse_dev_open,
> + .release = vduse_dev_release,
> + .read_iter = vduse_dev_read_iter,
> + .write_iter = vduse_dev_write_iter,
> + .poll = vduse_dev_poll,
> + .unlocked_ioctl = vduse_dev_ioctl,
> + .compat_ioctl = compat_ptr_ioctl,
> + .llseek = noop_llseek,
> +};
> +
> +static struct vduse_dev *vduse_dev_create(void)
> +{
> + struct vduse_dev *dev = kzalloc(sizeof(*dev), GFP_KERNEL);
> +
> + if (!dev)
> + return NULL;
> +
> + mutex_init(&dev->lock);
> + spin_lock_init(&dev->msg_lock);
> + INIT_LIST_HEAD(&dev->send_list);
> + INIT_LIST_HEAD(&dev->recv_list);
> + spin_lock_init(&dev->irq_lock);
> +
> + INIT_WORK(&dev->inject, vduse_dev_irq_inject);
> + init_waitqueue_head(&dev->waitq);
> +
> + return dev;
> +}
> +
> +static void vduse_dev_destroy(struct vduse_dev *dev)
> +{
> + kfree(dev);
> +}
> +
> +static struct vduse_dev *vduse_find_dev(const char *name)
> +{
> + struct vduse_dev *dev;
> + int id;
> +
> + idr_for_each_entry(&vduse_idr, dev, id)
> + if (!strcmp(dev->name, name))
> + return dev;
> +
> + return NULL;
> +}
> +
> +static int vduse_destroy_dev(char *name)
> +{
> + struct vduse_dev *dev = vduse_find_dev(name);
> +
> + if (!dev)
> + return -EINVAL;
> +
> + mutex_lock(&dev->lock);
> + if (dev->vdev || dev->connected) {
> + mutex_unlock(&dev->lock);
> + return -EBUSY;
> + }
> + dev->connected = true;
> + mutex_unlock(&dev->lock);
> +
> + vduse_dev_msg_cleanup(dev);
> + device_destroy(vduse_class, MKDEV(MAJOR(vduse_major), dev->minor));
> + idr_remove(&vduse_idr, dev->minor);
> + kvfree(dev->config);
> + kfree(dev->vqs);
> + vduse_domain_destroy(dev->domain);
> + kfree(dev->name);
> + vduse_dev_destroy(dev);
> + module_put(THIS_MODULE);
> +
> + return 0;
> +}
> +
> +static bool device_is_allowed(u32 device_id)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(allowed_device_id); i++)
> + if (allowed_device_id[i] == device_id)
> + return true;
> +
> + return false;
> +}
> +
> +static bool features_is_valid(u64 features)
> +{
> + if (!(features & (1ULL << VIRTIO_F_ACCESS_PLATFORM)))
> + return false;
> +
> + /* Now we only support read-only configuration space */
> + if (features & (1ULL << VIRTIO_BLK_F_CONFIG_WCE))
> + return false;
> +
> + return true;
> +}
> +
> +static bool vduse_validate_config(struct vduse_dev_config *config)
> +{
> + if (config->bounce_size > VDUSE_MAX_BOUNCE_SIZE)
> + return false;
> +
> + if (config->vq_align > PAGE_SIZE)
> + return false;
> +
> + if (config->config_size > PAGE_SIZE)
> + return false;
> +
> + if (!device_is_allowed(config->device_id))
> + return false;
> +
> + if (!features_is_valid(config->features))
> + return false;


Do we need to validate whether or not config_size is too small otherwise
we may have OOB access in get_config()?


> +
> + return true;
> +}
> +
> +static int vduse_create_dev(struct vduse_dev_config *config,
> + void *config_buf, u64 api_version)
> +{
> + int i, ret;
> + struct vduse_dev *dev;
> +
> + ret = -EEXIST;
> + if (vduse_find_dev(config->name))
> + goto err;
> +
> + ret = -ENOMEM;
> + dev = vduse_dev_create();
> + if (!dev)
> + goto err;
> +
> + dev->api_version = api_version;
> + dev->user_features = config->features;
> + dev->device_id = config->device_id;
> + dev->vendor_id = config->vendor_id;
> + dev->name = kstrdup(config->name, GFP_KERNEL);
> + if (!dev->name)
> + goto err_str;
> +
> + dev->domain = vduse_domain_create(VDUSE_IOVA_SIZE - 1,
> + config->bounce_size);
> + if (!dev->domain)
> + goto err_domain;
> +
> + dev->config = config_buf;
> + dev->config_size = config->config_size;
> + dev->vq_align = config->vq_align;
> + dev->vq_size_max = config->vq_size_max;
> + dev->vq_num = config->vq_num;
> + dev->vqs = kcalloc(dev->vq_num, sizeof(*dev->vqs), GFP_KERNEL);
> + if (!dev->vqs)
> + goto err_vqs;
> +
> + for (i = 0; i < dev->vq_num; i++) {
> + dev->vqs[i].index = i;
> + INIT_WORK(&dev->vqs[i].inject, vduse_vq_irq_inject);
> + spin_lock_init(&dev->vqs[i].kick_lock);
> + spin_lock_init(&dev->vqs[i].irq_lock);
> + }
> +
> + ret = idr_alloc(&vduse_idr, dev, 1, VDUSE_DEV_MAX, GFP_KERNEL);
> + if (ret < 0)
> + goto err_idr;
> +
> + dev->minor = ret;
> + dev->dev = device_create(vduse_class, NULL,
> + MKDEV(MAJOR(vduse_major), dev->minor),
> + NULL, "%s", config->name);
> + if (IS_ERR(dev->dev)) {
> + ret = PTR_ERR(dev->dev);
> + goto err_dev;
> + }
> + __module_get(THIS_MODULE);
> +
> + return 0;
> +err_dev:
> + idr_remove(&vduse_idr, dev->minor);
> +err_idr:
> + kfree(dev->vqs);
> +err_vqs:
> + vduse_domain_destroy(dev->domain);
> +err_domain:
> + kfree(dev->name);
> +err_str:
> + vduse_dev_destroy(dev);
> +err:
> + kvfree(config_buf);
> + return ret;
> +}
> +
> +static long vduse_ioctl(struct file *file, unsigned int cmd,
> + unsigned long arg)
> +{
> + int ret;
> + void __user *argp = (void __user *)arg;
> + struct vduse_control *control = file->private_data;
> +
> + mutex_lock(&vduse_lock);
> + switch (cmd) {
> + case VDUSE_GET_API_VERSION:
> + ret = put_user(control->api_version, (u64 __user *)argp);
> + break;
> + case VDUSE_SET_API_VERSION: {
> + u64 api_version;
> +
> + ret = -EFAULT;
> + if (get_user(api_version, (u64 __user *)argp))
> + break;
> +
> + ret = -EINVAL;
> + if (api_version > VDUSE_API_VERSION)
> + break;
> +
> + ret = 0;
> + control->api_version = api_version;
> + break;
> + }
> + case VDUSE_CREATE_DEV: {
> + struct vduse_dev_config config;
> + unsigned long size = offsetof(struct vduse_dev_config, config);
> + void *buf;
> +
> + ret = -EFAULT;
> + if (copy_from_user(&config, argp, size))
> + break;
> +
> + ret = -EINVAL;
> + if (vduse_validate_config(&config) == false)
> + break;
> +
> + buf = vmemdup_user(argp + size, config.config_size);
> + if (IS_ERR(buf)) {
> + ret = PTR_ERR(buf);
> + break;
> + }
> + ret = vduse_create_dev(&config, buf, control->api_version);
> + break;
> + }
> + case VDUSE_DESTROY_DEV: {
> + char name[VDUSE_NAME_MAX];
> +
> + ret = -EFAULT;
> + if (copy_from_user(name, argp, VDUSE_NAME_MAX))
> + break;
> +
> + ret = vduse_destroy_dev(name);
> + break;
> + }
> + default:
> + ret = -EINVAL;
> + break;
> + }
> + mutex_unlock(&vduse_lock);
> +
> + return ret;
> +}
> +
> +static int vduse_release(struct inode *inode, struct file *file)
> +{
> + struct vduse_control *control = file->private_data;
> +
> + kfree(control);
> + return 0;
> +}
> +
> +static int vduse_open(struct inode *inode, struct file *file)
> +{
> + struct vduse_control *control;
> +
> + control = kmalloc(sizeof(struct vduse_control), GFP_KERNEL);
> + if (!control)
> + return -ENOMEM;
> +
> + control->api_version = VDUSE_API_VERSION;
> + file->private_data = control;
> +
> + return 0;
> +}
> +
> +static const struct file_operations vduse_ctrl_fops = {
> + .owner = THIS_MODULE,
> + .open = vduse_open,
> + .release = vduse_release,
> + .unlocked_ioctl = vduse_ioctl,
> + .compat_ioctl = compat_ptr_ioctl,
> + .llseek = noop_llseek,
> +};
> +
> +static char *vduse_devnode(struct device *dev, umode_t *mode)
> +{
> + return kasprintf(GFP_KERNEL, "vduse/%s", dev_name(dev));
> +}
> +
> +static void vduse_mgmtdev_release(struct device *dev)
> +{
> +}
> +
> +static struct device vduse_mgmtdev = {
> + .init_name = "vduse",
> + .release = vduse_mgmtdev_release,
> +};
> +
> +static struct vdpa_mgmt_dev mgmt_dev;
> +
> +static int vduse_dev_init_vdpa(struct vduse_dev *dev, const char *name)
> +{
> + struct vduse_vdpa *vdev;
> + int ret;
> +
> + if (dev->vdev)
> + return -EEXIST;
> +
> + vdev = vdpa_alloc_device(struct vduse_vdpa, vdpa, dev->dev,
> + &vduse_vdpa_config_ops, name, true);
> + if (!vdev)
> + return -ENOMEM;
> +
> + dev->vdev = vdev;
> + vdev->dev = dev;
> + vdev->vdpa.dev.dma_mask = &vdev->vdpa.dev.coherent_dma_mask;
> + ret = dma_set_mask_and_coherent(&vdev->vdpa.dev, DMA_BIT_MASK(64));
> + if (ret) {
> + put_device(&vdev->vdpa.dev);
> + return ret;
> + }
> + set_dma_ops(&vdev->vdpa.dev, &vduse_dev_dma_ops);
> + vdev->vdpa.dma_dev = &vdev->vdpa.dev;
> + vdev->vdpa.mdev = &mgmt_dev;
> +
> + return 0;
> +}
> +
> +static int vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name)
> +{
> + struct vduse_dev *dev;
> + int ret;
> +
> + mutex_lock(&vduse_lock);
> + dev = vduse_find_dev(name);
> + if (!dev) {
> + mutex_unlock(&vduse_lock);
> + return -EINVAL;
> + }
> + ret = vduse_dev_init_vdpa(dev, name);
> + mutex_unlock(&vduse_lock);
> + if (ret)
> + return ret;
> +
> + ret = _vdpa_register_device(&dev->vdev->vdpa, dev->vq_num);
> + if (ret) {
> + put_device(&dev->vdev->vdpa.dev);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static void vdpa_dev_del(struct vdpa_mgmt_dev *mdev, struct vdpa_device *dev)
> +{
> + _vdpa_unregister_device(dev);
> +}
> +
> +static const struct vdpa_mgmtdev_ops vdpa_dev_mgmtdev_ops = {
> + .dev_add = vdpa_dev_add,
> + .dev_del = vdpa_dev_del,
> +};
> +
> +static struct virtio_device_id id_table[] = {
> + { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
> + { 0 },
> +};
> +
> +static struct vdpa_mgmt_dev mgmt_dev = {
> + .device = &vduse_mgmtdev,
> + .id_table = id_table,
> + .ops = &vdpa_dev_mgmtdev_ops,
> +};
> +
> +static int vduse_mgmtdev_init(void)
> +{
> + int ret;
> +
> + ret = device_register(&vduse_mgmtdev);
> + if (ret)
> + return ret;
> +
> + ret = vdpa_mgmtdev_register(&mgmt_dev);
> + if (ret)
> + goto err;
> +
> + return 0;
> +err:
> + device_unregister(&vduse_mgmtdev);
> + return ret;
> +}
> +
> +static void vduse_mgmtdev_exit(void)
> +{
> + vdpa_mgmtdev_unregister(&mgmt_dev);
> + device_unregister(&vduse_mgmtdev);
> +}
> +
> +static int vduse_init(void)
> +{
> + int ret;
> + struct device *dev;
> +
> + vduse_class = class_create(THIS_MODULE, "vduse");
> + if (IS_ERR(vduse_class))
> + return PTR_ERR(vduse_class);
> +
> + vduse_class->devnode = vduse_devnode;
> +
> + ret = alloc_chrdev_region(&vduse_major, 0, VDUSE_DEV_MAX, "vduse");
> + if (ret)
> + goto err_chardev_region;
> +
> + /* /dev/vduse/control */
> + cdev_init(&vduse_ctrl_cdev, &vduse_ctrl_fops);
> + vduse_ctrl_cdev.owner = THIS_MODULE;
> + ret = cdev_add(&vduse_ctrl_cdev, vduse_major, 1);
> + if (ret)
> + goto err_ctrl_cdev;
> +
> + dev = device_create(vduse_class, NULL, vduse_major, NULL, "control");
> + if (IS_ERR(dev)) {
> + ret = PTR_ERR(dev);
> + goto err_device;
> + }
> +
> + /* /dev/vduse/$DEVICE */
> + cdev_init(&vduse_cdev, &vduse_dev_fops);
> + vduse_cdev.owner = THIS_MODULE;
> + ret = cdev_add(&vduse_cdev, MKDEV(MAJOR(vduse_major), 1),
> + VDUSE_DEV_MAX - 1);
> + if (ret)
> + goto err_cdev;
> +
> + vduse_irq_wq = alloc_workqueue("vduse-irq",
> + WQ_HIGHPRI | WQ_SYSFS | WQ_UNBOUND, 0);
> + if (!vduse_irq_wq)
> + goto err_wq;
> +
> + ret = vduse_domain_init();
> + if (ret)
> + goto err_domain;
> +
> + ret = vduse_mgmtdev_init();
> + if (ret)
> + goto err_mgmtdev;
> +
> + return 0;
> +err_mgmtdev:
> + vduse_domain_exit();
> +err_domain:
> + destroy_workqueue(vduse_irq_wq);
> +err_wq:
> + cdev_del(&vduse_cdev);
> +err_cdev:
> + device_destroy(vduse_class, vduse_major);
> +err_device:
> + cdev_del(&vduse_ctrl_cdev);
> +err_ctrl_cdev:
> + unregister_chrdev_region(vduse_major, VDUSE_DEV_MAX);
> +err_chardev_region:
> + class_destroy(vduse_class);
> + return ret;
> +}
> +module_init(vduse_init);
> +
> +static void vduse_exit(void)
> +{
> + vduse_mgmtdev_exit();
> + vduse_domain_exit();
> + destroy_workqueue(vduse_irq_wq);
> + cdev_del(&vduse_cdev);
> + device_destroy(vduse_class, vduse_major);
> + cdev_del(&vduse_ctrl_cdev);
> + unregister_chrdev_region(vduse_major, VDUSE_DEV_MAX);
> + class_destroy(vduse_class);
> +}
> +module_exit(vduse_exit);
> +
> +MODULE_LICENSE(DRV_LICENSE);
> +MODULE_AUTHOR(DRV_AUTHOR);
> +MODULE_DESCRIPTION(DRV_DESC);
> diff --git a/include/uapi/linux/vduse.h b/include/uapi/linux/vduse.h
> new file mode 100644
> index 000000000000..f21b2e51b5c8
> --- /dev/null
> +++ b/include/uapi/linux/vduse.h
> @@ -0,0 +1,143 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +#ifndef _UAPI_VDUSE_H_
> +#define _UAPI_VDUSE_H_
> +
> +#include <linux/types.h>
> +
> +#define VDUSE_API_VERSION 0
> +
> +#define VDUSE_NAME_MAX 256
> +
> +/* the control messages definition for read/write */
> +
> +enum vduse_req_type {
> + /* Get the state for virtqueue from userspace */
> + VDUSE_GET_VQ_STATE,
> + /* Notify userspace to start the dataplane, no reply */
> + VDUSE_START_DATAPLANE,
> + /* Notify userspace to stop the dataplane, no reply */
> + VDUSE_STOP_DATAPLANE,
> + /* Notify userspace to update the memory mapping in device IOTLB */
> + VDUSE_UPDATE_IOTLB,
> +};
> +
> +struct vduse_vq_state {
> + __u32 index; /* virtqueue index */
> + __u32 avail_idx; /* virtqueue state (last_avail_idx) */
> +};


This needs some tweaks to support packed virtqueue.


> +
> +struct vduse_iova_range {
> + __u64 start; /* start of the IOVA range */
> + __u64 last; /* end of the IOVA range */
> +};
> +
> +struct vduse_dev_request {
> + __u32 type; /* request type */
> + __u32 request_id; /* request id */
> +#define VDUSE_REQ_FLAGS_NO_REPLY (1 << 0) /* No need to reply */
> + __u32 flags; /* request flags */
> + __u32 reserved; /* for future use */
> + union {
> + struct vduse_vq_state vq_state; /* virtqueue state */
> + struct vduse_iova_range iova; /* iova range for updating */
> + __u32 padding[16]; /* padding */
> + };
> +};
> +
> +struct vduse_dev_response {
> + __u32 request_id; /* corresponding request id */
> +#define VDUSE_REQ_RESULT_OK 0x00
> +#define VDUSE_REQ_RESULT_FAILED 0x01
> + __u32 result; /* the result of request */
> + __u32 reserved[2]; /* for future use */
> + union {
> + struct vduse_vq_state vq_state; /* virtqueue state */
> + __u32 padding[16]; /* padding */
> + };
> +};
> +
> +/* ioctls */
> +
> +struct vduse_dev_config {
> + char name[VDUSE_NAME_MAX]; /* vduse device name */
> + __u32 vendor_id; /* virtio vendor id */
> + __u32 device_id; /* virtio device id */
> + __u64 features; /* device features */
> + __u64 bounce_size; /* bounce buffer size for iommu */
> + __u16 vq_size_max; /* the max size of virtqueue */
> + __u16 padding; /* padding */
> + __u32 vq_num; /* the number of virtqueues */
> + __u32 vq_align; /* the allocation alignment of virtqueue's metadata */
> + __u32 config_size; /* the size of the configuration space */
> + __u32 reserved[15]; /* for future use */
> + __u8 config[0]; /* the buffer of the configuration space */
> +};
> +
> +struct vduse_iotlb_entry {
> + __u64 offset; /* the mmap offset on fd */
> + __u64 start; /* start of the IOVA range */
> + __u64 last; /* last of the IOVA range */
> +#define VDUSE_ACCESS_RO 0x1
> +#define VDUSE_ACCESS_WO 0x2
> +#define VDUSE_ACCESS_RW 0x3
> + __u8 perm; /* access permission of this range */
> +};
> +
> +struct vduse_config_update {
> + __u32 offset; /* offset from the beginning of configuration space */
> + __u32 length; /* the length to write to configuration space */
> + __u8 buffer[0]; /* buffer used to write from */
> +};
> +
> +struct vduse_vq_info {
> + __u32 index; /* virtqueue index */
> + __u32 avail_idx; /* virtqueue state (last_avail_idx) */
> + __u64 desc_addr; /* address of desc area */
> + __u64 driver_addr; /* address of driver area */
> + __u64 device_addr; /* address of device area */
> + __u32 num; /* the size of virtqueue */
> + __u8 ready; /* ready status of virtqueue */
> +};
> +
> +struct vduse_vq_eventfd {
> + __u32 index; /* virtqueue index */
> +#define VDUSE_EVENTFD_DEASSIGN -1
> + int fd; /* eventfd, -1 means de-assigning the eventfd */
> +};
> +
> +#define VDUSE_BASE 0x81
> +
> +/* Get the version of VDUSE API. This is used for future extension */
> +#define VDUSE_GET_API_VERSION _IOR(VDUSE_BASE, 0x00, __u64)
> +
> +/* Set the version of VDUSE API. */
> +#define VDUSE_SET_API_VERSION _IOW(VDUSE_BASE, 0x01, __u64)
> +
> +/* Create a vduse device which is represented by a char device (/dev/vduse/<name>) */
> +#define VDUSE_CREATE_DEV _IOW(VDUSE_BASE, 0x02, struct vduse_dev_config)
> +
> +/* Destroy a vduse device. Make sure there are no references to the char device */
> +#define VDUSE_DESTROY_DEV _IOW(VDUSE_BASE, 0x03, char[VDUSE_NAME_MAX])
> +
> +/*
> + * Get a file descriptor for the first overlapped iova region,
> + * -EINVAL means the iova region doesn't exist.
> + */
> +#define VDUSE_IOTLB_GET_FD _IOWR(VDUSE_BASE, 0x04, struct vduse_iotlb_entry)
> +
> +/* Get the negotiated features */
> +#define VDUSE_DEV_GET_FEATURES _IOR(VDUSE_BASE, 0x05, __u64)
> +
> +/* Update the configuration space */
> +#define VDUSE_DEV_UPDATE_CONFIG _IOW(VDUSE_BASE, 0x06, struct vduse_config_update)
> +
> +/* Get the specified virtqueue's information */
> +#define VDUSE_VQ_GET_INFO _IOWR(VDUSE_BASE, 0x07, struct vduse_vq_info)
> +
> +/* Setup an eventfd to receive kick for virtqueue */
> +#define VDUSE_VQ_SETUP_KICKFD _IOW(VDUSE_BASE, 0x08, struct vduse_vq_eventfd)
> +
> +/* Inject an interrupt for specific virtqueue */
> +#define VDUSE_VQ_INJECT_IRQ _IOW(VDUSE_BASE, 0x09, __u32)
> +
> +#endif /* _UAPI_VDUSE_H_ */

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