Re: [PATCH v8 09/10] vduse: Introduce VDUSE - vDPA Device in Userspace
From: Jason Wang
Date: Tue Jun 22 2021 - 01:07:23 EST
在 2021/6/21 下午6:41, Yongji Xie 写道:
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?
See below.
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.
Right.
+ 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.
We need fix a way to propagate the error to the userspace.
E.g if we want to stop the deivce, we will delay the status reset until
we get respose from the userspace?
+ }
+}
+
+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.
The uAPI doesn't prevent us from the following scenario:
update_config(mac[0], ..);
update_config(max[1], ..);
So it looks to me it's better to separate the config interrupt from the
config updating.
+ break;
+ }
+ case VDUSE_VQ_GET_INFO: {
Do we need to limit this only when DRIVER_OK is set?
Any reason to add this limitation?
Otherwise the vq is not fully initialized, e.g the desc_addr might not
be correct.
+ 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.
It should work.
Thanks
+
+ 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