Re: Re: [PATCH v8 09/10] vduse: Introduce VDUSE - vDPA Device in Userspace
From: Yongji Xie
Date: Mon Jun 21 2021 - 06:41:55 EST
On Mon, Jun 21, 2021 at 5:14 PM Jason Wang <jasowang@xxxxxxxxxx> wrote:
>
>
> 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@xxxxxxxxxxxxx>
> > ---
> > 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@xxxxxxxxxxxxx>
> > + *
> > + */
> > +
> > +#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@xxxxxxxxxxxxx>"
> > +#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.
>
OK.
>
> > + u64 features;
>
>
> And driver features.
>
OK.
>
> > + 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().
>
Do we need to handle the error in this case if we remove the no_reply
flag. Print a warning message?
> 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.
>
Looks like we can't, e.g. we need to get a reply from userspace for vq state.
>
> > + 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?
>
Good point.
>
> > +}
> > +
> > +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()?
>
Looks good to me.
>
> > + 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.
>
Will do it.
>
> > +
> > + 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.
>
Will do it.
>
> > +
> > + 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.
>
OK. So it still needs to be synchronized here. If so, how to handle
the error? Looks like printing a warning message should be enough.
>
> > + }
> > +}
> > +
> > +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.
>
I have documented it in the docs. Looks like a config update should be
always followed by a config interrupt. I didn't find a case that uses
them separately.
>
> > + break;
> > + }
> > + case VDUSE_VQ_GET_INFO: {
>
>
> Do we need to limit this only when DRIVER_OK is set?
>
Any reason to add this limitation?
>
> > + 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()?
>
How about adding validation in get_config()? It seems to be hard to
define the lower bound.
>
> > +
> > + 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.
>
OK.
Thanks,
Yongji