Jason Wang
2021-Mar-05 03:20 UTC
[RFC v4 07/11] vduse: Introduce VDUSE - vDPA Device in Userspace
On 2021/3/4 4:05 ??, Yongji Xie wrote:> On Thu, Mar 4, 2021 at 2:27 PM Jason Wang <jasowang at redhat.com> wrote: >> >> On 2021/2/23 7:50 ??, Xie Yongji wrote: >>> This VDUSE driver enables implementing vDPA devices in userspace. >>> Both control path and data path of vDPA devices will be able to >>> be handled in userspace. >>> >>> In the control path, the VDUSE driver will make use of message >>> mechnism to forward the config operation from vdpa bus driver >>> to userspace. Userspace can use read()/write() to receive/reply >>> those control messages. >>> >>> In the data path, VDUSE_IOTLB_GET_FD ioctl will be used to get >>> the file descriptors referring to vDPA device's iova regions. Then >>> userspace can use mmap() to access those iova regions. Besides, >>> userspace can use ioctl() to inject interrupt and use the eventfd >>> mechanism to receive virtqueue kicks. >>> >>> Signed-off-by: Xie Yongji <xieyongji at 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 | 1348 ++++++++++++++++++++ >>> include/uapi/linux/vduse.h | 136 ++ >>> 6 files changed, 1501 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 a4c75a28c839..71722e6f8f23 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 ffd1e098bfd2..92f07715e3b6 100644 >>> --- a/drivers/vdpa/Kconfig >>> +++ b/drivers/vdpa/Kconfig >>> @@ -25,6 +25,16 @@ config VDPA_SIM_NET >>> help >>> vDPA networking device simulator which loops TX traffic back to RX. >>> >>> +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 d160e9b63a66..66e97778ad03 100644 >>> --- a/drivers/vdpa/Makefile >>> +++ b/drivers/vdpa/Makefile >>> @@ -1,5 +1,6 @@ >>> # 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-$(CONFIG_MLX5_VDPA) += mlx5/ >>> diff --git a/drivers/vdpa/vdpa_user/Makefile b/drivers/vdpa/vdpa_user/Makefile >>> new file mode 100644 >>> index 000000000000..260e0b26af99 >>> --- /dev/null >>> +++ b/drivers/vdpa/vdpa_user/Makefile >>> @@ -0,0 +1,5 @@ >>> +# SPDX-License-Identifier: GPL-2.0 >>> + >>> +vduse-y := vduse_dev.o iova_domain.o >>> + >>> +obj-$(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..393bf99c48be >>> --- /dev/null >>> +++ b/drivers/vdpa/vdpa_user/vduse_dev.c >>> @@ -0,0 +1,1348 @@ >>> +// SPDX-License-Identifier: GPL-2.0-only >>> +/* >>> + * VDUSE: vDPA Device in Userspace >>> + * >>> + * Copyright (C) 2020 Bytedance Inc. and/or its affiliates. All rights reserved. >>> + * >>> + * Author: Xie Yongji <xieyongji at bytedance.com> >>> + * >>> + */ >>> + >>> +#include <linux/init.h> >>> +#include <linux/module.h> >>> +#include <linux/miscdevice.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 <uapi/linux/vduse.h> >>> +#include <uapi/linux/vdpa.h> >>> +#include <uapi/linux/virtio_config.h> >>> +#include <linux/mod_devicetable.h> >>> + >>> +#include "iova_domain.h" >>> + >>> +#define DRV_VERSION "1.0" >>> +#define DRV_AUTHOR "Yongji Xie <xieyongji at bytedance.com>" >>> +#define DRV_DESC "vDPA Device in Userspace" >>> +#define DRV_LICENSE "GPL v2" >>> + >>> +#define VDUSE_DEV_MAX (1U << MINORBITS) >>> + >>> +struct vduse_virtqueue { >>> + u16 index; >>> + bool ready; >>> + spinlock_t kick_lock; >>> + spinlock_t irq_lock; >>> + struct eventfd_ctx *kickfd; >>> + struct vdpa_callback cb; >>> +}; >>> + >>> +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 cdev cdev; >>> + struct vduse_virtqueue *vqs; >>> + struct vduse_iova_domain *domain; >>> + struct vhost_iotlb *iommu; >>> + spinlock_t iommu_lock; >>> + atomic_t bounce_map; >>> + struct mutex msg_lock; >>> + atomic64_t msg_unique; >> >> "next_request_id" should be better. >> > OK. > >>> + wait_queue_head_t waitq; >>> + struct list_head send_list; >>> + struct list_head recv_list; >>> + struct list_head list; >>> + bool connected; >>> + int minor; >>> + u16 vq_size_max; >>> + u16 vq_num; >>> + u32 vq_align; >>> + u32 device_id; >>> + u32 vendor_id; >>> +}; >>> + >>> +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; >>> +}; >>> + >>> +static unsigned long max_bounce_size = (64 * 1024 * 1024); >>> +module_param(max_bounce_size, ulong, 0444); >>> +MODULE_PARM_DESC(max_bounce_size, "Maximum bounce buffer size. (default: 64M)"); >>> + >>> +static unsigned long max_iova_size = (128 * 1024 * 1024); >>> +module_param(max_iova_size, ulong, 0444); >>> +MODULE_PARM_DESC(max_iova_size, "Maximum iova space size (default: 128M)"); >>> + >>> +static DEFINE_MUTEX(vduse_lock); >>> +static LIST_HEAD(vduse_devs); >>> +static DEFINE_IDA(vduse_ida); >>> + >>> +static dev_t vduse_major; >>> +static struct class *vduse_class; >>> + >>> +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 unique) >>> +{ >>> + struct vduse_dev_msg *tmp, *msg = NULL; >>> + >>> + list_for_each_entry(tmp, head, list) { >> >> Shoudl we use list_for_each_entry_safe()? >> > Looks like list_for_each_entry() is ok here. We will break the loop > after deleting one node.Right.> >>> + if (tmp->req.unique == unique) { >>> + msg = tmp; >>> + list_del(&tmp->list); >>> + break; >>> + } >>> + } >>> + >>> + return msg; >>> +} >>> + >>> +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_sync(struct vduse_dev *dev, struct vduse_dev_msg *msg) >>> +{ >>> + int ret; >>> + >>> + init_waitqueue_head(&msg->waitq); >>> + mutex_lock(&dev->msg_lock); >>> + vduse_enqueue_msg(&dev->send_list, msg); >>> + wake_up(&dev->waitq); >>> + mutex_unlock(&dev->msg_lock); >>> + ret = wait_event_interruptible(msg->waitq, msg->completed); >>> + mutex_lock(&dev->msg_lock); >>> + if (!msg->completed) >>> + list_del(&msg->list); >>> + else >>> + ret = msg->resp.result; >>> + mutex_unlock(&dev->msg_lock); >>> + >>> + return ret; >>> +} >>> + >>> +static u64 vduse_dev_get_features(struct vduse_dev *dev) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_GET_FEATURES; >>> + msg.req.unique = atomic64_fetch_inc(&dev->msg_unique); >>> + >>> + return vduse_dev_msg_sync(dev, &msg) ? 0 : msg.resp.features; >>> +} >>> + >>> +static int vduse_dev_set_features(struct vduse_dev *dev, u64 features) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_SET_FEATURES; >>> + msg.req.unique = atomic64_fetch_inc(&dev->msg_unique); >>> + msg.req.features = features; >>> + >>> + return vduse_dev_msg_sync(dev, &msg); >>> +} >>> + >>> +static u8 vduse_dev_get_status(struct vduse_dev *dev) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_GET_STATUS; >>> + msg.req.unique = atomic64_fetch_inc(&dev->msg_unique); >>> + >>> + return vduse_dev_msg_sync(dev, &msg) ? 0 : msg.resp.status; >>> +} >>> + >>> +static void vduse_dev_set_status(struct vduse_dev *dev, u8 status) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_SET_STATUS; >>> + msg.req.unique = atomic64_fetch_inc(&dev->msg_unique); >>> + msg.req.status = status; >>> + >>> + vduse_dev_msg_sync(dev, &msg); >>> +} >>> + >>> +static void vduse_dev_get_config(struct vduse_dev *dev, unsigned int offset, >>> + void *buf, unsigned int len) >> >> Btw, the ident looks odd here and other may places wherhe functions has >> more than one line of arguments. >> > OK, will fix it. > >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + unsigned int sz; >>> + >>> + while (len) { >>> + sz = min_t(unsigned int, len, sizeof(msg.req.config.data)); >>> + msg.req.type = VDUSE_GET_CONFIG; >>> + msg.req.unique = atomic64_fetch_inc(&dev->msg_unique); >>> + msg.req.config.offset = offset; >>> + msg.req.config.len = sz; >>> + vduse_dev_msg_sync(dev, &msg); >>> + memcpy(buf, msg.resp.config.data, sz); >>> + buf += sz; >>> + offset += sz; >>> + len -= sz; >>> + } >>> +} >>> + >>> +static void vduse_dev_set_config(struct vduse_dev *dev, unsigned int offset, >>> + const void *buf, unsigned int len) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + unsigned int sz; >>> + >>> + while (len) { >>> + sz = min_t(unsigned int, len, sizeof(msg.req.config.data)); >>> + msg.req.type = VDUSE_SET_CONFIG; >>> + msg.req.unique = atomic64_fetch_inc(&dev->msg_unique); >>> + msg.req.config.offset = offset; >>> + msg.req.config.len = sz; >>> + memcpy(msg.req.config.data, buf, sz); >>> + vduse_dev_msg_sync(dev, &msg); >>> + buf += sz; >>> + offset += sz; >>> + len -= sz; >>> + } >>> +} >>> + >>> +static void vduse_dev_set_vq_num(struct vduse_dev *dev, >>> + struct vduse_virtqueue *vq, u32 num) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_SET_VQ_NUM; >>> + msg.req.unique = atomic64_fetch_inc(&dev->msg_unique); >>> + msg.req.vq_num.index = vq->index; >>> + msg.req.vq_num.num = num; >>> + >>> + vduse_dev_msg_sync(dev, &msg); >>> +} >>> + >>> +static int vduse_dev_set_vq_addr(struct vduse_dev *dev, >>> + struct vduse_virtqueue *vq, u64 desc_addr, >>> + u64 driver_addr, u64 device_addr) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_SET_VQ_ADDR; >>> + msg.req.unique = atomic64_fetch_inc(&dev->msg_unique); >>> + msg.req.vq_addr.index = vq->index; >>> + msg.req.vq_addr.desc_addr = desc_addr; >>> + msg.req.vq_addr.driver_addr = driver_addr; >>> + msg.req.vq_addr.device_addr = device_addr; >>> + >>> + return vduse_dev_msg_sync(dev, &msg); >>> +} >>> + >>> +static void vduse_dev_set_vq_ready(struct vduse_dev *dev, >>> + struct vduse_virtqueue *vq, bool ready) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_SET_VQ_READY; >>> + msg.req.unique = atomic64_fetch_inc(&dev->msg_unique); >>> + msg.req.vq_ready.index = vq->index; >>> + msg.req.vq_ready.ready = ready; >>> + >>> + vduse_dev_msg_sync(dev, &msg); >>> +} >>> + >>> +static bool vduse_dev_get_vq_ready(struct vduse_dev *dev, >>> + struct vduse_virtqueue *vq) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_GET_VQ_READY; >>> + msg.req.unique = atomic64_fetch_inc(&dev->msg_unique); >>> + msg.req.vq_ready.index = vq->index; >>> + >>> + return vduse_dev_msg_sync(dev, &msg) ? false : msg.resp.vq_ready.ready; >>> +} >>> + >>> +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; >>> + >>> + msg.req.type = VDUSE_GET_VQ_STATE; >>> + msg.req.unique = atomic64_fetch_inc(&dev->msg_unique); >>> + msg.req.vq_state.index = vq->index; >>> + >>> + ret = vduse_dev_msg_sync(dev, &msg); >>> + if (!ret) >>> + state->avail_index = msg.resp.vq_state.avail_idx; >>> + >>> + return ret; >>> +} >>> + >>> +static int vduse_dev_set_vq_state(struct vduse_dev *dev, >>> + struct vduse_virtqueue *vq, >>> + const struct vdpa_vq_state *state) >>> +{ >>> + struct vduse_dev_msg msg = { 0 }; >>> + >>> + msg.req.type = VDUSE_SET_VQ_STATE; >>> + msg.req.unique = atomic64_fetch_inc(&dev->msg_unique); >>> + msg.req.vq_state.index = vq->index; >>> + msg.req.vq_state.avail_idx = state->avail_index; >>> + >>> + return vduse_dev_msg_sync(dev, &msg); >>> +} >>> + >>> +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.unique = atomic64_fetch_inc(&dev->msg_unique); >>> + msg.req.iova.start = start; >>> + msg.req.iova.last = last; >>> + >>> + return vduse_dev_msg_sync(dev, &msg); >>> +} >>> + >>> +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 = 0; >>> + >>> + if (iov_iter_count(to) < size) >>> + return 0; >>> + >>> + mutex_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; >>> + >>> + mutex_unlock(&dev->msg_lock); >>> + ret = wait_event_interruptible_exclusive(dev->waitq, >>> + !list_empty(&dev->send_list)); >>> + if (ret) >>> + return ret; >>> + >>> + mutex_lock(&dev->msg_lock); >>> + } >>> + ret = copy_to_iter(&msg->req, size, to); >>> + if (ret != size) { >>> + ret = -EFAULT; >>> + vduse_enqueue_msg(&dev->send_list, msg); >>> + goto unlock; >>> + } >>> + vduse_enqueue_msg(&dev->recv_list, msg); >>> +unlock: >>> + mutex_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; >>> + >>> + mutex_lock(&dev->msg_lock); >>> + msg = vduse_find_msg(&dev->recv_list, resp.request_id); >>> + if (!msg) { >>> + ret = -EINVAL; >>> + goto unlock; >>> + } >>> + >>> + memcpy(&msg->resp, &resp, sizeof(resp)); >>> + msg->completed = 1; >>> + wake_up(&msg->waitq); >>> +unlock: >>> + mutex_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; >>> + >>> + return mask; >>> +} >>> + >>> +static int vduse_iotlb_add_range(struct vduse_dev *dev, >>> + u64 start, u64 last, >>> + u64 addr, unsigned int perm, >>> + struct file *file, u64 offset) >>> +{ >>> + struct vdpa_map_file *map_file; >>> + int ret; >>> + >>> + map_file = kmalloc(sizeof(*map_file), GFP_ATOMIC); >>> + if (!map_file) >>> + return -ENOMEM; >>> + >>> + map_file->file = get_file(file); >>> + map_file->offset = offset; >>> + >>> + spin_lock(&dev->iommu_lock); >>> + ret = vhost_iotlb_add_range_ctx(dev->iommu, start, last, >>> + addr, perm, map_file); >>> + spin_unlock(&dev->iommu_lock); >>> + if (ret) { >>> + fput(map_file->file); >>> + kfree(map_file); >>> + return ret; >>> + } >>> + return 0; >>> +} >>> + >>> +static void vduse_iotlb_del_range(struct vduse_dev *dev, u64 start, u64 last) >>> +{ >>> + struct vdpa_map_file *map_file; >>> + struct vhost_iotlb_map *map; >>> + >>> + spin_lock(&dev->iommu_lock); >>> + while ((map = vhost_iotlb_itree_first(dev->iommu, start, last))) { >>> + map_file = (struct vdpa_map_file *)map->opaque; >>> + fput(map_file->file); >>> + kfree(map_file); >>> + vhost_iotlb_map_free(dev->iommu, map); >>> + } >>> + spin_unlock(&dev->iommu_lock); >>> +} >>> + >>> +static void vduse_dev_reset(struct vduse_dev *dev) >>> +{ >>> + int i; >>> + >>> + atomic_set(&dev->bounce_map, 0); >>> + vduse_iotlb_del_range(dev, 0ULL, ULLONG_MAX); >>> + vduse_dev_update_iotlb(dev, 0ULL, ULLONG_MAX); >>> + >>> + for (i = 0; i < dev->vq_num; i++) { >>> + struct vduse_virtqueue *vq = &dev->vqs[i]; >>> + >>> + spin_lock(&vq->irq_lock); >>> + vq->ready = false; >>> + 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]; >>> + >>> + return vduse_dev_set_vq_addr(dev, vq, desc_area, >>> + driver_area, device_area); >>> +} >>> + >>> +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 && vq->kickfd) >>> + eventfd_signal(vq->kickfd, 1); >>> + 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]; >>> + >>> + vduse_dev_set_vq_num(dev, vq, 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]; >>> + >>> + vduse_dev_set_vq_ready(dev, vq, ready); >>> + 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]; >>> + >>> + vq->ready = vduse_dev_get_vq_ready(dev, vq); >>> + >>> + 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]; >>> + >>> + return vduse_dev_set_vq_state(dev, vq, state); >>> +} >>> + >>> +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); >>> + u64 fixed = (1ULL << VIRTIO_F_ACCESS_PLATFORM); >>> + >>> + return (vduse_dev_get_features(dev) | fixed); >> >> What happens if we don't do such fixup. I think we should fail if >> usersapce doesnt offer ACCESS_PLATFORM instead. >> > Make sense. > >>> +} >>> + >>> +static int vduse_vdpa_set_features(struct vdpa_device *vdpa, u64 features) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + >>> + return vduse_dev_set_features(dev, features); >>> +} >>> + >>> +static void vduse_vdpa_set_config_cb(struct vdpa_device *vdpa, >>> + struct vdpa_callback *cb) >>> +{ >>> + /* We don't support config interrupt */ >>> +} >>> + >>> +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 vduse_dev_get_status(dev); >>> +} >>> + >>> +static void vduse_vdpa_set_status(struct vdpa_device *vdpa, u8 status) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + >>> + if (status == 0) >>> + vduse_dev_reset(dev); >>> + >>> + vduse_dev_set_status(dev, status); >>> +} >>> + >>> +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); >>> + >>> + vduse_dev_get_config(dev, offset, buf, len); >>> +} >>> + >>> +static void vduse_vdpa_set_config(struct vdpa_device *vdpa, unsigned int offset, >>> + const void *buf, unsigned int len) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + >>> + vduse_dev_set_config(dev, offset, buf, len); >>> +} >>> + >>> +static int vduse_vdpa_set_map(struct vdpa_device *vdpa, >>> + struct vhost_iotlb *iotlb) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + struct vhost_iotlb_map *map; >>> + struct vdpa_map_file *map_file; >>> + u64 start = 0ULL, last = ULLONG_MAX; >>> + int ret = 0; >>> + >>> + vduse_iotlb_del_range(dev, start, last); >>> + >>> + for (map = vhost_iotlb_itree_first(iotlb, start, last); map; >>> + map = vhost_iotlb_itree_next(map, start, last)) { >>> + map_file = (struct vdpa_map_file *)map->opaque; >>> + if (!map_file->file) >>> + continue; >>> + >>> + ret = vduse_iotlb_add_range(dev, map->start, map->last, >>> + map->addr, map->perm, >>> + map_file->file, >>> + map_file->offset); >>> + if (ret) >>> + break; >>> + } >>> + vduse_dev_update_iotlb(dev, start, last); >>> + >>> + return ret; >>> +} >>> + >>> +static void vduse_vdpa_free(struct vdpa_device *vdpa) >>> +{ >>> + struct vduse_dev *dev = vdpa_to_vduse(vdpa); >>> + >>> + WARN_ON(!list_empty(&dev->send_list)); >>> + WARN_ON(!list_empty(&dev->recv_list)); >>> + 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 = vduse_vdpa_get_config, >>> + .set_config = vduse_vdpa_set_config, >>> + .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; >>> + >>> + if (atomic_xchg(&vdev->bounce_map, 1) == 0 && >>> + vduse_iotlb_add_range(vdev, 0, domain->bounce_size - 1, >>> + 0, VDUSE_ACCESS_RW, >>> + vduse_domain_file(domain), 0)) { >>> + atomic_set(&vdev->bounce_map, 0); >>> + return DMA_MAPPING_ERROR; >> >> Can we add the bounce mapping page by page here? >> > Do you mean mapping the bounce buffer to user space page by page? If > so, userspace needs to call lots of mmap() for that.I get this.> >>> + } >>> + >>> + 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; >>> + >>> + if (vduse_iotlb_add_range(vdev, iova, iova + size - 1, >>> + iova, VDUSE_ACCESS_RW, >>> + vduse_domain_file(domain), iova)) { >>> + vduse_domain_free_coherent(domain, size, addr, iova, attrs); >>> + 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; >>> + unsigned long start = (unsigned long)dma_addr; >>> + unsigned long last = start + size - 1; >>> + >>> + vduse_iotlb_del_range(vdev, start, last); >>> + vduse_dev_update_iotlb(vdev, start, last); >>> + vduse_domain_free_coherent(domain, size, vaddr, dma_addr, attrs); >>> +} >>> + >>> +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, >>> +}; >>> + >>> +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; >>> + >>> + if (eventfd->index >= dev->vq_num) >>> + return -EINVAL; >>> + >>> + vq = &dev->vqs[eventfd->index]; >>> + if (eventfd->fd > 0) { >>> + ctx = eventfd_ctx_fdget(eventfd->fd); >>> + if (IS_ERR(ctx)) >>> + return PTR_ERR(ctx); >>> + } >>> + spin_lock(&vq->kick_lock); >>> + if (vq->kickfd) >>> + eventfd_ctx_put(vq->kickfd); >>> + vq->kickfd = ctx; >>> + spin_unlock(&vq->kick_lock); >>> + >>> + return 0; >>> +} >>> + >>> +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 file *f = NULL; >>> + >>> + ret = -EFAULT; >>> + if (copy_from_user(&entry, argp, sizeof(entry))) >>> + break; >>> + >>> + spin_lock(&dev->iommu_lock); >>> + map = vhost_iotlb_itree_first(dev->iommu, 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(&dev->iommu_lock); >>> + if (!f) { >>> + ret = -EINVAL; >>> + break; >>> + } >>> + if (copy_to_user(argp, &entry, sizeof(entry))) { >>> + fput(f); >>> + ret = -EFAULT; >>> + break; >>> + } >>> + ret = get_unused_fd_flags(perm_to_file_flags(entry.perm)); >>> + if (ret < 0) { >>> + fput(f); >>> + break; >>> + } >>> + fd_install(ret, f); >>> + 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_INJECT_VQ_IRQ: { >>> + struct vduse_virtqueue *vq; >>> + >>> + ret = -EINVAL; >>> + if (arg >= dev->vq_num) >>> + break; >>> + >>> + vq = &dev->vqs[arg]; >>> + spin_lock_irq(&vq->irq_lock); >>> + if (vq->ready && vq->cb.callback) { >>> + vq->cb.callback(vq->cb.private); >>> + ret = 0; >>> + } >>> + spin_unlock_irq(&vq->irq_lock); >>> + 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; >>> + struct vduse_dev_msg *msg; >>> + int i; >>> + >>> + for (i = 0; i < dev->vq_num; i++) { >>> + struct vduse_virtqueue *vq = &dev->vqs[i]; >>> + >>> + spin_lock(&vq->kick_lock); >>> + if (vq->kickfd) >>> + eventfd_ctx_put(vq->kickfd); >>> + vq->kickfd = NULL; >>> + spin_unlock(&vq->kick_lock); >>> + } >>> + >>> + mutex_lock(&dev->msg_lock); >>> + while ((msg = vduse_dequeue_msg(&dev->recv_list))) >>> + vduse_enqueue_msg(&dev->send_list, msg); >>> + mutex_unlock(&dev->msg_lock); >>> + >>> + dev->connected = false; >>> + >>> + return 0; >>> +} >>> + >>> +static int vduse_dev_open(struct inode *inode, struct file *file) >>> +{ >>> + struct vduse_dev *dev = container_of(inode->i_cdev, >>> + struct vduse_dev, cdev); >>> + int ret = -EBUSY; >>> + >>> + mutex_lock(&vduse_lock); >>> + if (dev->connected) >>> + goto unlock; >>> + >>> + ret = 0; >>> + dev->connected = true; >>> + file->private_data = dev; >>> +unlock: >>> + mutex_unlock(&vduse_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; >>> + >>> + dev->iommu = vhost_iotlb_alloc(0, 0); >>> + if (!dev->iommu) { >>> + kfree(dev); >>> + return NULL; >>> + } >>> + >>> + mutex_init(&dev->msg_lock); >>> + INIT_LIST_HEAD(&dev->send_list); >>> + INIT_LIST_HEAD(&dev->recv_list); >>> + atomic64_set(&dev->msg_unique, 0); >>> + spin_lock_init(&dev->iommu_lock); >>> + atomic_set(&dev->bounce_map, 0); >>> + >>> + init_waitqueue_head(&dev->waitq); >>> + >>> + return dev; >>> +} >>> + >>> +static void vduse_dev_destroy(struct vduse_dev *dev) >>> +{ >>> + vhost_iotlb_free(dev->iommu); >>> + mutex_destroy(&dev->msg_lock); >>> + kfree(dev); >>> +} >>> + >>> +static struct vduse_dev *vduse_find_dev(const char *name) >>> +{ >>> + struct vduse_dev *tmp, *dev = NULL; >>> + >>> + list_for_each_entry(tmp, &vduse_devs, list) { >>> + if (!strcmp(dev_name(&tmp->dev), name)) { >>> + dev = tmp; >>> + break; >>> + } >>> + } >>> + return dev; >>> +} >>> + >>> +static int vduse_destroy_dev(char *name) >>> +{ >>> + struct vduse_dev *dev = vduse_find_dev(name); >>> + >>> + if (!dev) >>> + return -EINVAL; >>> + >>> + if (dev->vdev || dev->connected) >>> + return -EBUSY; >>> + >>> + dev->connected = true; >>> + list_del(&dev->list); >>> + cdev_device_del(&dev->cdev, &dev->dev); >>> + put_device(&dev->dev); >>> + >>> + return 0; >>> +} >>> + >>> +static void vduse_release_dev(struct device *device) >>> +{ >>> + struct vduse_dev *dev >>> + container_of(device, struct vduse_dev, dev); >>> + >>> + ida_simple_remove(&vduse_ida, dev->minor); >>> + kfree(dev->vqs); >>> + vduse_domain_destroy(dev->domain); >>> + vduse_dev_destroy(dev); >>> + module_put(THIS_MODULE); >>> +} >>> + >>> +static int vduse_create_dev(struct vduse_dev_config *config) >>> +{ >>> + int i, ret = -ENOMEM; >>> + struct vduse_dev *dev; >>> + >>> + if (config->bounce_size > max_bounce_size) >>> + return -EINVAL; >>> + >>> + if (config->bounce_size > max_iova_size) >>> + return -EINVAL; >>> + >>> + if (vduse_find_dev(config->name)) >>> + return -EEXIST; >>> + >>> + dev = vduse_dev_create(); >>> + if (!dev) >>> + return -ENOMEM; >>> + >>> + dev->device_id = config->device_id; >>> + dev->vendor_id = config->vendor_id; >>> + dev->domain = vduse_domain_create(max_iova_size - 1, >>> + config->bounce_size); >>> + if (!dev->domain) >>> + goto err_domain; >>> + >>> + 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; >>> + spin_lock_init(&dev->vqs[i].kick_lock); >>> + spin_lock_init(&dev->vqs[i].irq_lock); >>> + } >>> + >>> + ret = ida_simple_get(&vduse_ida, 0, VDUSE_DEV_MAX, GFP_KERNEL); >>> + if (ret < 0) >>> + goto err_ida; >>> + >>> + dev->minor = ret; >>> + device_initialize(&dev->dev); >>> + dev->dev.release = vduse_release_dev; >>> + dev->dev.class = vduse_class; >>> + dev->dev.devt = MKDEV(MAJOR(vduse_major), dev->minor); >>> + ret = dev_set_name(&dev->dev, "%s", config->name); >> >> Do we need to add a namespce here? E.g "vduse-%s", config->name. >> > Actually we already have a parent dir "/dev/vduse/" for it.Oh, right. Then it should be fine.> >>> + if (ret) >>> + goto err_name; >>> + >>> + cdev_init(&dev->cdev, &vduse_dev_fops); >>> + dev->cdev.owner = THIS_MODULE; >>> + >>> + ret = cdev_device_add(&dev->cdev, &dev->dev); >>> + if (ret) { >>> + put_device(&dev->dev); >>> + return ret; >>> + } >>> + list_add(&dev->list, &vduse_devs); >>> + __module_get(THIS_MODULE); >>> + >>> + return 0; >>> +err_name: >>> + ida_simple_remove(&vduse_ida, dev->minor); >>> +err_ida: >>> + kfree(dev->vqs); >>> +err_vqs: >>> + vduse_domain_destroy(dev->domain); >>> +err_domain: >>> + vduse_dev_destroy(dev); >>> + return ret; >>> +} >>> + >>> +static long vduse_ioctl(struct file *file, unsigned int cmd, >>> + unsigned long arg) >>> +{ >>> + int ret; >>> + void __user *argp = (void __user *)arg; >>> + >>> + mutex_lock(&vduse_lock); >>> + switch (cmd) { >>> + case VDUSE_CREATE_DEV: { >>> + struct vduse_dev_config config; >>> + >>> + ret = -EFAULT; >>> + if (copy_from_user(&config, argp, sizeof(config))) >>> + break; >>> + >>> + ret = vduse_create_dev(&config); >>> + 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 const struct file_operations vduse_fops = { >>> + .owner = THIS_MODULE, >>> + .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 struct miscdevice vduse_misc = { >>> + .fops = &vduse_fops, >>> + .minor = MISC_DYNAMIC_MINOR, >>> + .name = "vduse", >>> + .nodename = "vduse/control", >>> +}; >>> + >>> +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_add_vdpa(struct vduse_dev *dev, const char *name) >>> +{ >>> + struct vduse_vdpa *vdev = dev->vdev; >>> + int ret; >>> + >>> + if (vdev) >>> + return -EEXIST; >>> + >>> + vdev = vdpa_alloc_device(struct vduse_vdpa, vdpa, NULL, >> >> I think the char dev should be used as the parent here. >> > Agree. > >>> + &vduse_vdpa_config_ops, >>> + dev->vq_num, name, true); >>> + if (!vdev) >>> + return -ENOMEM; >>> + >>> + 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) >>> + goto err; >>> + >>> + set_dma_ops(&vdev->vdpa.dev, &vduse_dev_dma_ops); >>> + vdev->vdpa.dma_dev = &vdev->vdpa.dev; >>> + vdev->vdpa.mdev = &mgmt_dev; >>> + >>> + ret = _vdpa_register_device(&vdev->vdpa); >>> + if (ret) >>> + goto err; >>> + >>> + dev->vdev = vdev; >>> + >>> + return 0; >>> +err: >>> + put_device(&vdev->vdpa.dev); >>> + return ret; >>> +} >>> + >>> +static int vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name) >>> +{ >>> + struct vduse_dev *dev; >>> + int ret = -EINVAL; >>> + >>> + mutex_lock(&vduse_lock); >>> + dev = vduse_find_dev(name); >>> + if (!dev) >>> + goto unlock; >> >> Any reason for this check? I think vdpa core layer has already did for >> the name check for us. >> > We need to check whether the vduse device with the name is created.Yes.> >>> + >>> + ret = vduse_dev_add_vdpa(dev, name); >>> +unlock: >>> + mutex_unlock(&vduse_lock); >>> + >>> + return ret; >>> +} >>> + >>> +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_DEV_ANY_ID, 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; >>> + >>> + ret = misc_register(&vduse_misc); >>> + if (ret) >>> + return ret; >>> + >>> + vduse_class = class_create(THIS_MODULE, "vduse"); >>> + if (IS_ERR(vduse_class)) { >>> + ret = PTR_ERR(vduse_class); >>> + goto err_class; >>> + } >>> + vduse_class->devnode = vduse_devnode; >>> + >>> + ret = alloc_chrdev_region(&vduse_major, 0, VDUSE_DEV_MAX, "vduse"); >>> + if (ret) >>> + goto err_chardev; >>> + >>> + ret = vduse_domain_init(); >>> + if (ret) >>> + goto err_domain; >>> + >>> + ret = vduse_mgmtdev_init(); >>> + if (ret) >>> + goto err_mgmtdev; >> >> Should we validate max_bounce_size < max_iova_size here? >> > Sure. > >> >>> + >>> + return 0; >>> +err_mgmtdev: >>> + vduse_domain_exit(); >>> +err_domain: >>> + unregister_chrdev_region(vduse_major, VDUSE_DEV_MAX); >>> +err_chardev: >>> + class_destroy(vduse_class); >>> +err_class: >>> + misc_deregister(&vduse_misc); >>> + return ret; >>> +} >>> +module_init(vduse_init); >>> + >>> +static void vduse_exit(void) >>> +{ >>> + misc_deregister(&vduse_misc); >>> + class_destroy(vduse_class); >>> + unregister_chrdev_region(vduse_major, VDUSE_DEV_MAX); >>> + vduse_domain_exit(); >>> + vduse_mgmtdev_exit(); >>> +} >>> +module_exit(vduse_exit); >>> + >>> +MODULE_VERSION(DRV_VERSION); >>> +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..9391c4acfa53 >>> --- /dev/null >>> +++ b/include/uapi/linux/vduse.h >>> @@ -0,0 +1,136 @@ >>> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ >>> +#ifndef _UAPI_VDUSE_H_ >>> +#define _UAPI_VDUSE_H_ >>> + >>> +#include <linux/types.h> >>> + >>> +#define VDUSE_CONFIG_DATA_LEN 256 >>> +#define VDUSE_NAME_MAX 256 >>> + >>> +/* the control messages definition for read/write */ >>> + >>> +enum vduse_req_type { >>> + VDUSE_SET_VQ_NUM, >>> + VDUSE_SET_VQ_ADDR, >>> + VDUSE_SET_VQ_READY, >>> + VDUSE_GET_VQ_READY, >>> + VDUSE_SET_VQ_STATE, >>> + VDUSE_GET_VQ_STATE, >>> + VDUSE_SET_FEATURES, >>> + VDUSE_GET_FEATURES, >>> + VDUSE_SET_STATUS, >>> + VDUSE_GET_STATUS, >>> + VDUSE_SET_CONFIG, >>> + VDUSE_GET_CONFIG, >>> + VDUSE_UPDATE_IOTLB, >>> +}; >>> + >>> +struct vduse_vq_num { >>> + __u32 index; >>> + __u32 num; >>> +}; >>> + >>> +struct vduse_vq_addr { >>> + __u32 index; >>> + __u64 desc_addr; >>> + __u64 driver_addr; >>> + __u64 device_addr; >>> +}; >>> + >>> +struct vduse_vq_ready { >>> + __u32 index; >>> + __u8 ready; >>> +}; >>> + >>> +struct vduse_vq_state { >>> + __u32 index; >>> + __u16 avail_idx; >>> +}; >>> + >>> +struct vduse_dev_config_data { >>> + __u32 offset; >>> + __u32 len; >>> + __u8 data[VDUSE_CONFIG_DATA_LEN]; >>> +}; >>> + >>> +struct vduse_iova_range { >>> + __u64 start; >>> + __u64 last; >>> +}; >>> + >>> +struct vduse_dev_request { >>> + __u32 type; /* request type */ >>> + __u32 unique; /* request id */ >> >> Let's simply use "request_id" here. >> > OK. > >>> + __u32 reserved[2]; /* for feature use */ >>> + union { >>> + struct vduse_vq_num vq_num; /* virtqueue num */ >>> + struct vduse_vq_addr vq_addr; /* virtqueue address */ >>> + struct vduse_vq_ready vq_ready; /* virtqueue ready status */ >>> + struct vduse_vq_state vq_state; /* virtqueue state */ >>> + struct vduse_dev_config_data config; /* virtio device config space */ >>> + struct vduse_iova_range iova; /* iova range for updating */ >>> + __u64 features; /* virtio features */ >>> + __u8 status; /* device status */ >> >> It might be better to use struct for feaures and status as well for >> consistency. >> > OK. > >> And to be safe, let's add explicity padding here. >> > Do you mean add padding for the union?I think so.> >>> + }; >>> +}; >>> + >>> +struct vduse_dev_response { >>> + __u32 request_id; /* corresponding request id */ >>> +#define VDUSE_REQUEST_OK 0x00 >>> +#define VDUSE_REQUEST_FAILED 0x01 >>> + __u8 result; /* the result of request */ >>> + __u8 reserved[11]; /* for feature use */ >> >> Looks like this will be a hole which is similar to >> 429711aec282c4b5fe5bbd7b2f0bbbff4110ffb2. Need to make sure the reserved >> end at 8 byte boundary. >> > Will fix it. > >>> + union { >>> + struct vduse_vq_ready vq_ready; /* virtqueue ready status */ >>> + struct vduse_vq_state vq_state; /* virtqueue state */ >>> + struct vduse_dev_config_data config; /* virtio device config space */ >>> + __u64 features; /* virtio features */ >>> + __u8 status; /* device status */ >>> + }; >>> +}; >>> + >>> +/* 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 bounce_size; /* bounce buffer size for iommu */ >>> + __u16 vq_num; /* the number of virtqueues */ >>> + __u16 vq_size_max; /* the max size of virtqueue */ >>> + __u32 vq_align; /* the allocation alignment of virtqueue's metadata */ >>> +}; >>> + >>> +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_vq_eventfd { >>> + __u32 index; /* virtqueue index */ >>> + int fd; /* eventfd, -1 means de-assigning the eventfd */ >> >> Let's define a macro for this. >> > OK. > >>> +}; >>> + >>> +#define VDUSE_BASE 0x81 >>> + >>> +/* Create a vduse device which is represented by a char device (/dev/vduse/<name>) */ >>> +#define VDUSE_CREATE_DEV _IOW(VDUSE_BASE, 0x01, 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, 0x02, char[VDUSE_NAME_MAX]) >>> + >>> +/* Get a file descriptor for the mmap'able iova region */ >>> +#define VDUSE_IOTLB_GET_FD _IOWR(VDUSE_BASE, 0x03, struct vduse_iotlb_entry) >>> + >>> +/* Setup an eventfd to receive kick for virtqueue */ >>> +#define VDUSE_VQ_SETUP_KICKFD _IOW(VDUSE_BASE, 0x04, struct vduse_vq_eventfd) >>> + >>> +/* Inject an interrupt for specific virtqueue */ >>> +#define VDUSE_INJECT_VQ_IRQ _IO(VDUSE_BASE, 0x05) >> >> I wonder do we need a version/feature handshake that is for future >> extension instead of just reserve bits in uABI? E.g VDUSE_GET_VERSION ... >> > Agree. Will do it in v5.Btw, I think you can remove "RFC" then Michael can consider to merge the series. Thanks> > Thanks, > Yongji >