在 2021/3/24 下午4:55, Yongji Xie 写道:
On Wed, Mar 24, 2021 at 12:43 PM Jason Wang <jasowang@xxxxxxxxxx> wrote:在 2021/3/15 下午1:37, Xie Yongji 写道: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, userspace can use mmap() to access vDPA device's iova regions obtained through VDUSE_IOTLB_GET_ENTRY ioctl. Besides, userspace can use ioctl() to inject interrupt and use the eventfd mechanism to receive virtqueue kicks. 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 | 1281 ++++++++++++++++++++ include/uapi/linux/vduse.h | 153 +++ 6 files changed, 1451 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 a245809c99d0..77a1da522c21 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 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..07d0ae92d470 --- /dev/null +++ b/drivers/vdpa/vdpa_user/vduse_dev.c @@ -0,0 +1,1281 @@ +// 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@xxxxxxxxxxxxx> + * + */ + +#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@xxxxxxxxxxxxx>" +#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 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 cdev cdev; + struct vduse_virtqueue *vqs; + struct vduse_iova_domain *domain; + spinlock_t msg_lock; + atomic64_t msg_unique; + 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 struct workqueue_struct *vduse_irq_wq; + +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 *tmp, *msg = NULL; + + list_for_each_entry(tmp, head, list) { + if (tmp->req.request_id == request_id) { + 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) +{ + init_waitqueue_head(&msg->waitq); + spin_lock(&dev->msg_lock); + vduse_enqueue_msg(&dev->send_list, msg); + wake_up(&dev->waitq); + spin_unlock(&dev->msg_lock); + wait_event_interruptible(msg->waitq, msg->completed); + spin_lock(&dev->msg_lock); + if (!msg->completed) + list_del(&msg->list); + spin_unlock(&dev->msg_lock); + + return (msg->resp.result == VDUSE_REQUEST_OK) ? 0 : -1; +} + +static u64 vduse_dev_get_features(struct vduse_dev *dev) +{ + struct vduse_dev_msg msg = { 0 }; + + msg.req.type = VDUSE_GET_FEATURES; + msg.req.request_id = atomic64_fetch_inc(&dev->msg_unique);Let's introduce a helper for the atomic64_fetch_inc() here.Fine.+ + return vduse_dev_msg_sync(dev, &msg) ? 0 : msg.resp.f.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.request_id = atomic64_fetch_inc(&dev->msg_unique); + msg.req.f.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.request_id = atomic64_fetch_inc(&dev->msg_unique); + + return vduse_dev_msg_sync(dev, &msg) ? 0 : msg.resp.s.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.request_id = atomic64_fetch_inc(&dev->msg_unique); + msg.req.s.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) +{ + 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.request_id = 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.request_id = 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.request_id = 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.request_id = 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.request_id = 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.request_id = 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.request_id = 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.request_id = 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; + + if (last < start) + return -EINVAL; + + msg = kzalloc(sizeof(*msg), GFP_ATOMIC);The return value is not checked.Will fix it.+ msg->req.type = VDUSE_UPDATE_IOTLB;What would usespace do after receiving VDUSE_UPDATE_IOTLB? If it still needs to issue VDUSE_GET_ENTRY with probably -EINVAL, it's kind of overkill. So it looks to me that the VDUSE_UPDATE_IOTLB is acutally kind of flush or unmap here. If this is true, should we introduce a new type or just rename it as VDUSE_IOTLB_UNMAP?VDUSE_UPDATE_IOTLB is used to notify userspace of refreshing (include mapping and unmapping) the iotlb mapping. The reason why we can't use flush/unmap is explained below.+ msg->req.request_id = 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; + + 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; + } + 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 = -EINVAL; + 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;EPOLLOUT is missed here?Why do we need EPOLLOUT here?
It means the fd is ready to be wrote?
+ + return mask; +} + +static void vduse_dev_reset(struct vduse_dev *dev) +{ + int i; + + vduse_domain_reset_bounce_map(dev->domain); + vduse_dev_update_iotlb(dev, 0ULL, ULLONG_MAX);Simialrly, IOTLB update should be done before the resetting?The problem is userspace can still get valid bounce mapping through VDUSE_IOTLB_GET_ENTRY between receiving IOTLB_UNMAP and bounce mapping reset. Then userspace has no way to know when to invalidate these mappings.
Right, I think it might be helpful to add a comment here to explain the order.
And it would be helpful to add comment to explain how coherent mappings is handled.OK. It would be handled in vduse_dev_free_coherent().+ + 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); + + return vduse_dev_get_features(dev); +} + +static int vduse_vdpa_set_features(struct vdpa_device *vdpa, u64 features) +{ + struct vduse_dev *dev = vdpa_to_vduse(vdpa); + + if (!(features & (1ULL << VIRTIO_F_ACCESS_PLATFORM))) + return -EINVAL; + + 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); + int ret; +So I wonder we need to do the vhost_dev_update_iotlb() before vduse_domain_set_map(). That is, we need to make sure the userspace's IOTLB is cleared after setting up the new map?The same problem I described above. So we use UPDATE_IOTLB messages to notify userspace of refreshing the IOTLB after we change the iotlb itree.
Yes.
+ ret = vduse_domain_set_map(dev->domain, iotlb); + vduse_dev_update_iotlb(dev, 0ULL, ULLONG_MAX); + + 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; + + 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; + vduse_dev_update_iotlb(vdev, iova, iova + size - 1); + + 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_domain_free_coherent(domain, size, vaddr, dma_addr, attrs); + vduse_dev_update_iotlb(vdev, start, last); +} + +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); + } 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; + spin_unlock(&vq->kick_lock); + + return 0; +} + +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_ENTRY: { + 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; + + spin_lock(&domain->iotlb_lock); + map = vhost_iotlb_itree_first(domain->iotlb, + entry.start, entry.start + 1); + 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;So we need document this in the uAPI doc. I think when userspace see -EINVAL it means the map doesn't exist.Fine with me.Or should we make it more explicitly by e.g introduing new flags.+ if (!f) + break; + + ret = -EFAULT; + if (copy_to_user(argp, &entry, sizeof(entry))) { + fput(f); + break; + } + ret = receive_fd_user(f, argp, perm_to_file_flags(entry.perm)); + fput(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: + ret = -EINVAL; + if (arg >= dev->vq_num) + break; + + ret = 0; + queue_work(vduse_irq_wq, &dev->vqs[arg].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; + 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); + } + + spin_lock(&dev->msg_lock); + while ((msg = vduse_dequeue_msg(&dev->recv_list))) + vduse_enqueue_msg(&dev->send_list, msg);What's the goal of this?Support reconnecting. Make sure userspace daemon can get the inflight messages after reboot.
I see, plase add a comment for this.
In addition to free the messages, we need wake up the processes that is in the waitq in this case.+ spin_unlock(&dev->msg_lock); + + dev->connected = false;Do we need to hold vduse mutex here?Looks like I didn't find any situation that requires the mutex.
Ok, I guess the reason is because there will be no external reference for the device?
+ + 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; + + spin_lock_init(&dev->msg_lock); + INIT_LIST_HEAD(&dev->send_list); + INIT_LIST_HEAD(&dev->recv_list); + atomic64_set(&dev->msg_unique, 0); + + 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 *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;Need mutex here?vduse_destroy_dev() is protected by the vduse_mutex.
I see.
+ 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; + 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 = 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); + 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:So the rewind after device_initialize() looks wrong, we should use put_device() which will use dev.relase().Oh, yes. We should also call put_device() in err_name case.See the comment of device_initialize(): * NOTE: Use put_device() to give up your reference instead of freeing * @dev directly once you have called this function. */+ 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_GET_API_VERSION: + ret = VDUSE_API_VERSION;To preseve the uAPI compatibility, besides GET_API_VERSION, we need SET_API_VERSION to support older userspace.Shouldn't the userspace keep compatibility to support older kernel? If so, we only need GET_API_VERSION here.
Actually the reverse. The new kernel need to make sure the old userspace can work. That is to say the kenrel should support version 0 forever even if it supports e.g version 1.
In this case, we should let userspace to choose which version it wants to use.
Thanks
And we need probably all the ioctls when API version is not set from userspace.+ break; + 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, &dev->dev, + &vduse_vdpa_config_ops, 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, dev->vq_num); + 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; + + 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; + + if (max_bounce_size >= max_iova_size) + return -EINVAL; + + 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; + + 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: + 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); + destroy_workqueue(vduse_irq_wq); + 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..37f7d7059aa8 --- /dev/null +++ b/include/uapi/linux/vduse.h @@ -0,0 +1,153 @@ +/* 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_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, +};Need comment to explain each type.Fine.+ +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_features { + __u64 features; +}; + +struct vduse_status { + __u8 status; +};Need comment for all the above uapi.Fine.+ +struct vduse_dev_request { + __u32 type; /* request type */ + __u32 request_id; /* request id */ + __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 */ + struct vduse_features f; /* virtio features */ + struct vduse_status s; /* device status */ + __u32 padding[16]; /* padding */ + }; +}; + +struct vduse_dev_response { + __u32 request_id; /* corresponding request id */ +#define VDUSE_REQUEST_OK 0x00 +#define VDUSE_REQUEST_FAILED 0x01 + __u32 result; /* the result of request */ + __u32 reserved[2]; /* for feature use */ + 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 */ + struct vduse_features f; /* virtio features */ + struct vduse_status s; /* device status */ + __u32 padding[16]; /* padding */ + }; +}; + +/* ioctls */ + +struct vduse_dev_config { + char name[VDUSE_NAME_MAX]; /* vduse device name */ + __u32 vendor_id; /* virtio vendor id */ + __u32 device_id; /* virtio device id */ + __u64 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 { + int fd; +#define VDUSE_ACCESS_RO 0x1 +#define VDUSE_ACCESS_WO 0x2 +#define VDUSE_ACCESS_RW 0x3 + __u8 perm; /* access permission of this range */Let's re-order the perm or add explict padding here to avoid hole.OK. Thanks, Yongji
