Re: [PATCH 5/5] vdpasim: vDPA device simulator

Zhu Lingshan
2020-02-04T08:22:13Z

On 1/16/2020 8:42 PM, Jason Wang wrote:
> This patch implements a software vDPA networking device. The datapath
> is implemented through vringh and workqueue. The device has an on-chip
> IOMMU which translates IOVA to PA. For kernel virtio drivers, vDPA
> simulator driver provides dma_ops. For vhost driers, set_map() methods
> of vdpa_config_ops is implemented to accept mappings from vhost.
>
> A sysfs based management interface is implemented, devices are
> created and removed through:
>
> /sys/devices/virtual/vdpa_simulator/netdev/{create|remove}
>
> Netlink based lifecycle management could be implemented for vDPA
> simulator as well.
>
> Currently, vDPA device simulator will loopback TX traffic to RX. So
> the main use case for the device is vDPA feature testing, prototyping
> and development.
>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
> drivers/virtio/vdpa/Kconfig | 17 +
> drivers/virtio/vdpa/Makefile | 1 +
> drivers/virtio/vdpa/vdpa_sim.c | 796 +++++++++++++++++++++++++++++++++
> 3 files changed, 814 insertions(+)
> create mode 100644 drivers/virtio/vdpa/vdpa_sim.c
>
> diff --git a/drivers/virtio/vdpa/Kconfig b/drivers/virtio/vdpa/Kconfig
> index 3032727b4d98..12ec25d48423 100644
> --- a/drivers/virtio/vdpa/Kconfig
> +++ b/drivers/virtio/vdpa/Kconfig
> @@ -7,3 +7,20 @@ config VDPA
> datapath which complies with virtio specifications with
> vendor specific control path.
>
> +menuconfig VDPA_MENU
> + bool "VDPA drivers"
> + default n
> +
> +if VDPA_MENU
> +
> +config VDPA_SIM
> + tristate "vDPA device simulator"
> + select VDPA
> + default n
> + help
> + vDPA networking device simulator which loop TX traffic back
> + to RX. This device is used for testing, prototyping and
> + development of vDPA.
> +
> +endif # VDPA_MENU
> +
> diff --git a/drivers/virtio/vdpa/Makefile b/drivers/virtio/vdpa/Makefile
> index ee6a35e8a4fb..5ec0e6ae3c57 100644
> --- a/drivers/virtio/vdpa/Makefile
> +++ b/drivers/virtio/vdpa/Makefile
> @@ -1,2 +1,3 @@
> # SPDX-License-Identifier: GPL-2.0
> obj-$(CONFIG_VDPA) += vdpa.o
> +obj-$(CONFIG_VDPA_SIM) += vdpa_sim.o
> diff --git a/drivers/virtio/vdpa/vdpa_sim.c b/drivers/virtio/vdpa/vdpa_sim.c
> new file mode 100644
> index 000000000000..85a235f99e3d
> --- /dev/null
> +++ b/drivers/virtio/vdpa/vdpa_sim.c
> @@ -0,0 +1,796 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * VDPA networking device simulator.
> + *
> + * Copyright (c) 2020, Red Hat Inc. All rights reserved.
> + * Author: Jason Wang <jasowang@redhat.com>
> + *
> + */
> +
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/device.h>
> +#include <linux/kernel.h>
> +#include <linux/fs.h>
> +#include <linux/poll.h>
> +#include <linux/slab.h>
> +#include <linux/sched.h>
> +#include <linux/wait.h>
> +#include <linux/uuid.h>
> +#include <linux/iommu.h>
> +#include <linux/sysfs.h>
> +#include <linux/file.h>
> +#include <linux/etherdevice.h>
> +#include <linux/vringh.h>
> +#include <linux/vdpa.h>
> +#include <linux/vhost_iotlb.h>
> +#include <uapi/linux/virtio_config.h>
> +#include <uapi/linux/virtio_net.h>
> +
> +#define DRV_VERSION "0.1"
> +#define DRV_AUTHOR "Jason Wang <jasowang@redhat.com>"
> +#define DRV_DESC "vDPA Device Simulator"
> +#define DRV_LICENSE "GPL v2"
> +
> +struct vdpasim_dev {
> + struct class *vd_class;
> + struct idr vd_idr;
> + struct device dev;
> + struct kobject *devices_kobj;
> +};
> +
> +struct vdpasim_dev *vdpasim_dev;
> +
> +struct vdpasim_virtqueue {
> + struct vringh vring;
> + struct vringh_kiov iov;
> + unsigned short head;
> + bool ready;
> + u64 desc_addr;
> + u64 device_addr;
> + u64 driver_addr;
> + u32 num;
> + void *private;
> + irqreturn_t (*cb)(void *data);
> +};
> +
> +#define VDPASIM_QUEUE_ALIGN PAGE_SIZE
> +#define VDPASIM_QUEUE_MAX 256
> +#define VDPASIM_DEVICE_ID 0x1
> +#define VDPASIM_VENDOR_ID 0
> +#define VDPASIM_VQ_NUM 0x2
> +#define VDPASIM_CLASS_NAME "vdpa_simulator"
> +#define VDPASIM_NAME "netdev"
> +
> +u64 vdpasim_features = (1ULL << VIRTIO_F_ANY_LAYOUT) |
> + (1ULL << VIRTIO_F_VERSION_1) |
> + (1ULL << VIRTIO_F_IOMMU_PLATFORM);
> +
> +/* State of each vdpasim device */
> +struct vdpasim {
> + struct vdpasim_virtqueue vqs[2];
> + struct work_struct work;
> + /* spinlock to synchronize virtqueue state */
> + spinlock_t lock;
> + struct vdpa_device vdpa;
> + struct virtio_net_config config;
> + struct vhost_iotlb *iommu;
> + void *buffer;
> + u32 status;
> + u32 generation;
> + u64 features;
> + struct list_head next;
> + guid_t uuid;
> + char name[64];
> +};
> +
> +static struct mutex vsim_list_lock;
> +static struct list_head vsim_devices_list;
> +
> +static struct vdpasim *vdpa_to_sim(struct vdpa_device *vdpa)
> +{
> + return container_of(vdpa, struct vdpasim, vdpa);
> +}
> +
> +static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
> +{
> + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
> + int ret;
> +
> + ret = vringh_init_iotlb(&vq->vring, vdpasim_features, VDPASIM_QUEUE_MAX,
> + false, (struct vring_desc *)vq->desc_addr,
> + (struct vring_avail *)vq->driver_addr,
> + (struct vring_used *)vq->device_addr);
> +}
> +
> +static void vdpasim_vq_reset(struct vdpasim_virtqueue *vq)
> +{
> + vq->ready = 0;
> + vq->desc_addr = 0;
> + vq->driver_addr = 0;
> + vq->device_addr = 0;
> + vq->cb = NULL;
> + vq->private = NULL;
> + vringh_init_iotlb(&vq->vring, vdpasim_features, VDPASIM_QUEUE_MAX,
> + false, 0, 0, 0);
> +}
> +
> +static void vdpasim_reset(struct vdpasim *vdpasim)
> +{
> + int i;
> +
> + for (i = 0; i < VDPASIM_VQ_NUM; i++)
> + vdpasim_vq_reset(&vdpasim->vqs[i]);
> +
> + vhost_iotlb_reset(vdpasim->iommu);
> +
> + vdpasim->features = 0;
> + vdpasim->status = 0;
> + ++vdpasim->generation;
> +}
> +
> +static void vdpasim_work(struct work_struct *work)
> +{
> + struct vdpasim *vdpasim = container_of(work, struct
> + vdpasim, work);
> + struct vdpasim_virtqueue *txq = &vdpasim->vqs[1];
> + struct vdpasim_virtqueue *rxq = &vdpasim->vqs[0];
> + size_t read, write, total_write;
> + int err;
> + int pkts = 0;
> +
> + spin_lock(&vdpasim->lock);
> +
> + if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
> + goto out;
> +
> + if (!txq->ready || !rxq->ready)
> + goto out;
> +
> + while (true) {
> + total_write = 0;
> + err = vringh_getdesc_iotlb(&txq->vring, &txq->iov, NULL,
> + &txq->head, GFP_ATOMIC);
> + if (err <= 0)
> + break;
> +
> + err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->iov,
> + &rxq->head, GFP_ATOMIC);
> + if (err <= 0) {
> + vringh_complete_iotlb(&txq->vring, txq->head, 0);
> + break;
> + }
> +
> + while (true) {
> + read = vringh_iov_pull_iotlb(&txq->vring, &txq->iov,
> + vdpasim->buffer,
> + PAGE_SIZE);
> + if (read <= 0)
> + break;
> +
> + write = vringh_iov_push_iotlb(&rxq->vring, &rxq->iov,
> + vdpasim->buffer, read);
> + if (write <= 0)
> + break;
> +
> + total_write += write;
> + }
> +
> + /* Make sure data is wrote before advancing index */
> + smp_wmb();
> +
> + vringh_complete_iotlb(&txq->vring, txq->head, 0);
> + vringh_complete_iotlb(&rxq->vring, rxq->head, total_write);
> +
> + /* Make sure used is visible before rasing the interrupt. */
> + smp_wmb();
> +
> + local_bh_disable();
> + if (txq->cb)
> + txq->cb(txq->private);
> + if (rxq->cb)
> + rxq->cb(rxq->private);
> + local_bh_enable();
> +
> + if (++pkts > 4) {
> + schedule_work(&vdpasim->work);
> + goto out;
> + }
> + }
> +
> +out:
> + spin_unlock(&vdpasim->lock);
> +}
> +
> +static int dir_to_perm(enum dma_data_direction dir)
> +{
> + int perm = -EFAULT;
> +
> + switch (dir) {
> + case DMA_FROM_DEVICE:
> + perm = VHOST_MAP_WO;
> + break;
> + case DMA_TO_DEVICE:
> + perm = VHOST_MAP_RO;
> + break;
> + case DMA_BIDIRECTIONAL:
> + perm = VHOST_MAP_RW;
> + break;
> + default:
> + break;
> + }
> +
> + return perm;
> +}
> +
> +static dma_addr_t vdpasim_map_page(struct device *dev, struct page *page,
> + unsigned long offset, size_t size,
> + enum dma_data_direction dir,
> + unsigned long attrs)
> +{
> + struct vdpa_device *vdpa = dev_to_vdpa(dev);
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> + struct vhost_iotlb *iommu = vdpasim->iommu;
> + u64 pa = (page_to_pfn(page) << PAGE_SHIFT) + offset;
> + int ret, perm = dir_to_perm(dir);
> +
> + if (perm < 0)
> + return DMA_MAPPING_ERROR;
> +
> + /* For simplicity, use identical mapping to avoid e.g iova
> + * allocator.
> + */
> + ret = vhost_iotlb_add_range(iommu, pa, pa + size - 1,
> + pa, dir_to_perm(dir));
> + if (ret)
> + return DMA_MAPPING_ERROR;
> +
> + return (dma_addr_t)(pa);
> +}
> +
> +static void vdpasim_unmap_page(struct device *dev, dma_addr_t dma_addr,
> + size_t size, enum dma_data_direction dir,
> + unsigned long attrs)
> +{
> + struct vdpa_device *vdpa = dev_to_vdpa(dev);
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> + struct vhost_iotlb *iommu = vdpasim->iommu;
> +
> + vhost_iotlb_del_range(iommu, (u64)dma_addr,
> + (u64)dma_addr + size - 1);
> +}
> +
> +static void *vdpasim_alloc_coherent(struct device *dev, size_t size,
> + dma_addr_t *dma_addr, gfp_t flag,
> + unsigned long attrs)
> +{
> + struct vdpa_device *vdpa = dev_to_vdpa(dev);
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> + struct vhost_iotlb *iommu = vdpasim->iommu;
> + void *addr = kmalloc(size, flag);
> + int ret;
> +
> + if (!addr)
> + *dma_addr = DMA_MAPPING_ERROR;
> + else {
> + u64 pa = virt_to_phys(addr);
> +
> + ret = vhost_iotlb_add_range(iommu, (u64)pa,
> + (u64)pa + size - 1,
> + pa, VHOST_MAP_RW);
> + if (ret) {
> + kfree(addr);
> + *dma_addr = DMA_MAPPING_ERROR;
> + } else
> + *dma_addr = (dma_addr_t)pa;
> + }
> +
> + return addr;
> +}
> +
> +static void vdpasim_free_coherent(struct device *dev, size_t size,
> + void *vaddr, dma_addr_t dma_addr,
> + unsigned long attrs)
> +{
> + struct vdpa_device *vdpa = dev_to_vdpa(dev);
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> + struct vhost_iotlb *iommu = vdpasim->iommu;
> +
> + vhost_iotlb_del_range(iommu, (u64)dma_addr,
> + (u64)dma_addr + size - 1);
> + kfree((void *)dma_addr);
> +}
> +
> +static const struct dma_map_ops vdpasim_dma_ops = {
> + .map_page = vdpasim_map_page,
> + .unmap_page = vdpasim_unmap_page,
> + .alloc = vdpasim_alloc_coherent,
> + .free = vdpasim_free_coherent,
> +};
> +

Hey Jason,

IMHO, it would be nice if dma_ops of the parent device could be re-used.
vdpa_device is expecting to represent a physical device except this
simulator, however, there are not enough information in vdpa_device.dev
to indicating which kind physical device it attached to. Namely
get_arch_dma_ops(struct bus type) can not work on vdpa_device.dev. Then
it seems device drivers need to implement a wrap of dma_ops of parent
devices. Can this work be done in the vdpa framework since it looks like
a common task? Can "vd_dev->vdev.dev.parent = vdpa->dev->parent;" in
virtio_vdpa_probe() do the work?

Thanks,
BR
Zhu Lingshan
> +static void vdpasim_release_dev(struct device *_d)
> +{
> + struct vdpa_device *vdpa = dev_to_vdpa(_d);
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> +
> + sysfs_remove_link(vdpasim_dev->devices_kobj, vdpasim->name);
> +
> + mutex_lock(&vsim_list_lock);
> + list_del(&vdpasim->next);
> + mutex_unlock(&vsim_list_lock);
> +
> + kfree(vdpasim->buffer);
> + kfree(vdpasim);
> +}
> +
> +static const struct vdpa_config_ops vdpasim_net_config_ops;
> +
> +static int vdpasim_create(const guid_t *uuid)
> +{
> + struct vdpasim *vdpasim, *tmp;
> + struct virtio_net_config *config;
> + struct vdpa_device *vdpa;
> + struct device *dev;
> + int ret = -ENOMEM;
> +
> + mutex_lock(&vsim_list_lock);
> + list_for_each_entry(tmp, &vsim_devices_list, next) {
> + if (guid_equal(&tmp->uuid, uuid)) {
> + mutex_unlock(&vsim_list_lock);
> + return -EEXIST;
> + }
> + }
> +
> + vdpasim = kzalloc(sizeof(*vdpasim), GFP_KERNEL);
> + if (!vdpasim)
> + goto err_vdpa_alloc;
> +
> + vdpasim->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
> + if (!vdpasim->buffer)
> + goto err_buffer_alloc;
> +
> + vdpasim->iommu = vhost_iotlb_alloc(2048, 0);
> + if (!vdpasim->iommu)
> + goto err_iotlb;
> +
> + config = &vdpasim->config;
> + config->mtu = 1500;
> + config->status = VIRTIO_NET_S_LINK_UP;
> + eth_random_addr(config->mac);
> +
> + INIT_WORK(&vdpasim->work, vdpasim_work);
> + spin_lock_init(&vdpasim->lock);
> +
> + guid_copy(&vdpasim->uuid, uuid);
> +
> + list_add(&vdpasim->next, &vsim_devices_list);
> + vdpa = &vdpasim->vdpa;
> +
> + mutex_unlock(&vsim_list_lock);
> +
> + vdpa = &vdpasim->vdpa;
> + vdpa->config = &vdpasim_net_config_ops;
> + vdpa_set_parent(vdpa, &vdpasim_dev->dev);
> + vdpa->dev.release = vdpasim_release_dev;
> +
> + vringh_set_iotlb(&vdpasim->vqs[0].vring, vdpasim->iommu);
> + vringh_set_iotlb(&vdpasim->vqs[1].vring, vdpasim->iommu);
> +
> + dev = &vdpa->dev;
> + dev->coherent_dma_mask = DMA_BIT_MASK(64);
> + set_dma_ops(dev, &vdpasim_dma_ops);
> +
> + ret = register_vdpa_device(vdpa);
> + if (ret)
> + goto err_register;
> +
> + sprintf(vdpasim->name, "%pU", uuid);
> +
> + ret = sysfs_create_link(vdpasim_dev->devices_kobj, &vdpa->dev.kobj,
> + vdpasim->name);
> + if (ret)
> + goto err_link;
> +
> + return 0;
> +
> +err_link:
> +err_register:
> + vhost_iotlb_free(vdpasim->iommu);
> + mutex_lock(&vsim_list_lock);
> + list_del(&vdpasim->next);
> + mutex_unlock(&vsim_list_lock);
> +err_iotlb:
> + kfree(vdpasim->buffer);
> +err_buffer_alloc:
> + kfree(vdpasim);
> +err_vdpa_alloc:
> + return ret;
> +}
> +
> +static int vdpasim_remove(const guid_t *uuid)
> +{
> + struct vdpasim *vds, *tmp;
> + struct vdpa_device *vdpa = NULL;
> + int ret = -EINVAL;
> +
> + mutex_lock(&vsim_list_lock);
> + list_for_each_entry_safe(vds, tmp, &vsim_devices_list, next) {
> + if (guid_equal(&vds->uuid, uuid)) {
> + vdpa = &vds->vdpa;
> + ret = 0;
> + break;
> + }
> + }
> + mutex_unlock(&vsim_list_lock);
> +
> + if (vdpa)
> + unregister_vdpa_device(vdpa);
> +
> + return ret;
> +}
> +
> +static int vdpasim_set_vq_address(struct vdpa_device *vdpa, u16 idx,
> + u64 desc_area, u64 driver_area,
> + u64 device_area)
> +{
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
> +
> + vq->desc_addr = desc_area;
> + vq->driver_addr = driver_area;
> + vq->device_addr = device_area;
> +
> + return 0;
> +}
> +
> +static void vdpasim_set_vq_num(struct vdpa_device *vdpa, u16 idx, u32 num)
> +{
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
> +
> + vq->num = num;
> +}
> +
> +static void vdpasim_kick_vq(struct vdpa_device *vdpa, u16 idx)
> +{
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
> +
> + if (vq->ready)
> + schedule_work(&vdpasim->work);
> +}
> +
> +static void vdpasim_set_vq_cb(struct vdpa_device *vdpa, u16 idx,
> + struct vdpa_callback *cb)
> +{
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
> +
> + vq->cb = cb->callback;
> + vq->private = cb->private;
> +}
> +
> +static void vdpasim_set_vq_ready(struct vdpa_device *vdpa, u16 idx, bool ready)
> +{
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
> +
> + spin_lock(&vdpasim->lock);
> + vq->ready = ready;
> + if (vq->ready)
> + vdpasim_queue_ready(vdpasim, idx);
> + spin_unlock(&vdpasim->lock);
> +}
> +
> +static bool vdpasim_get_vq_ready(struct vdpa_device *vdpa, u16 idx)
> +{
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
> +
> + return vq->ready;
> +}
> +
> +static int vdpasim_set_vq_state(struct vdpa_device *vdpa, u16 idx, u64 state)
> +{
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
> + struct vringh *vrh = &vq->vring;
> +
> + spin_lock(&vdpasim->lock);
> + vrh->last_avail_idx = state;
> + spin_unlock(&vdpasim->lock);
> +
> + return 0;
> +}
> +
> +static u64 vdpasim_get_vq_state(struct vdpa_device *vdpa, u16 idx)
> +{
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> + struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
> + struct vringh *vrh = &vq->vring;
> +
> + return vrh->last_avail_idx;
> +}
> +
> +static u16 vdpasim_get_vq_align(struct vdpa_device *vdpa)
> +{
> + return VDPASIM_QUEUE_ALIGN;
> +}
> +
> +static u64 vdpasim_get_features(struct vdpa_device *vdpa)
> +{
> + return vdpasim_features;
> +}
> +
> +static int vdpasim_set_features(struct vdpa_device *vdpa, u64 features)
> +{
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> +
> + /* DMA mapping must be done by driver */
> + if (!(features & (1ULL << VIRTIO_F_IOMMU_PLATFORM)))
> + return -EINVAL;
> +
> + vdpasim->features = features & vdpasim_features;
> +
> + return 0;
> +}
> +
> +static void vdpasim_set_config_cb(struct vdpa_device *vdpa,
> + struct vdpa_callback *cb)
> +{
> + /* We don't support config interrupt */
> +}
> +
> +static u16 vdpasim_get_vq_num_max(struct vdpa_device *vdpa)
> +{
> + return VDPASIM_QUEUE_MAX;
> +}
> +
> +static u32 vdpasim_get_device_id(struct vdpa_device *vdpa)
> +{
> + return VDPASIM_DEVICE_ID;
> +}
> +
> +static u32 vdpasim_get_vendor_id(struct vdpa_device *vdpa)
> +{
> + return VDPASIM_VENDOR_ID;
> +}
> +
> +static u8 vdpasim_get_status(struct vdpa_device *vdpa)
> +{
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> + u8 status;
> +
> + spin_lock(&vdpasim->lock);
> + status = vdpasim->status;
> + spin_unlock(&vdpasim->lock);
> +
> + return vdpasim->status;
> +}
> +
> +static void vdpasim_set_status(struct vdpa_device *vdpa, u8 status)
> +{
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> +
> + spin_lock(&vdpasim->lock);
> + vdpasim->status = status;
> + if (status == 0)
> + vdpasim_reset(vdpasim);
> + spin_unlock(&vdpasim->lock);
> +}
> +
> +static void vdpasim_get_config(struct vdpa_device *vdpa, unsigned int offset,
> + void *buf, unsigned int len)
> +{
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> +
> + if (offset + len < sizeof(struct virtio_net_config))
> + memcpy(buf, &vdpasim->config + offset, len);
> +}
> +
> +static void vdpasim_set_config(struct vdpa_device *vdpa, unsigned int offset,
> + const void *buf, unsigned int len)
> +{
> + /* No writable config supportted by vdpasim */
> +}
> +
> +static u32 vdpasim_get_generation(struct vdpa_device *vdpa)
> +{
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> +
> + return vdpasim->generation;
> +}
> +
> +static int vdpasim_set_map(struct vdpa_device *vdpa,
> + struct vhost_iotlb *iotlb)
> +{
> + struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
> + struct vhost_iotlb_map *map;
> + u64 start = 0ULL, last = 0ULL - 1;
> + int ret;
> +
> + vhost_iotlb_reset(vdpasim->iommu);
> +
> + for (map = vhost_iotlb_itree_first(iotlb, start, last); map;
> + map = vhost_iotlb_itree_next(map, start, last)) {
> + ret = vhost_iotlb_add_range(vdpasim->iommu, map->start,
> + map->last, map->addr, map->perm);
> + if (ret)
> + goto err;
> + }
> + return 0;
> +
> +err:
> + vhost_iotlb_reset(vdpasim->iommu);
> + return ret;
> +}
> +
> +static const struct vdpa_config_ops vdpasim_net_config_ops = {
> + .set_vq_address = vdpasim_set_vq_address,
> + .set_vq_num = vdpasim_set_vq_num,
> + .kick_vq = vdpasim_kick_vq,
> + .set_vq_cb = vdpasim_set_vq_cb,
> + .set_vq_ready = vdpasim_set_vq_ready,
> + .get_vq_ready = vdpasim_get_vq_ready,
> + .set_vq_state = vdpasim_set_vq_state,
> + .get_vq_state = vdpasim_get_vq_state,
> + .get_vq_align = vdpasim_get_vq_align,
> + .get_features = vdpasim_get_features,
> + .set_features = vdpasim_set_features,
> + .set_config_cb = vdpasim_set_config_cb,
> + .get_vq_num_max = vdpasim_get_vq_num_max,
> + .get_device_id = vdpasim_get_device_id,
> + .get_vendor_id = vdpasim_get_vendor_id,
> + .get_status = vdpasim_get_status,
> + .set_status = vdpasim_set_status,
> + .get_config = vdpasim_get_config,
> + .set_config = vdpasim_set_config,
> + .get_generation = vdpasim_get_generation,
> + .set_map = vdpasim_set_map,
> +};
> +
> +static void vdpasim_device_release(struct device *dev)
> +{
> + struct vdpasim_dev *vdpasim_dev =
> + container_of(dev, struct vdpasim_dev, dev);
> +
> + vdpasim_dev->dev.bus = NULL;
> + idr_destroy(&vdpasim_dev->vd_idr);
> + class_destroy(vdpasim_dev->vd_class);
> + vdpasim_dev->vd_class = NULL;
> + kfree(vdpasim_dev);
> +}
> +
> +static ssize_t create_store(struct kobject *kobj, struct kobj_attribute *attr,
> + const char *buf, size_t count)
> +{
> + char *str;
> + guid_t uuid;
> + int ret;
> +
> + if ((count < UUID_STRING_LEN) || (count > UUID_STRING_LEN + 1))
> + return -EINVAL;
> +
> + str = kstrndup(buf, count, GFP_KERNEL);
> + if (!str)
> + return -ENOMEM;
> +
> + ret = guid_parse(str, &uuid);
> + kfree(str);
> + if (ret)
> + return ret;
> +
> + ret = vdpasim_create(&uuid);
> + if (ret)
> + return ret;
> +
> + return count;
> +}
> +
> +static ssize_t remove_store(struct kobject *kobj, struct kobj_attribute *attr,
> + const char *buf, size_t count)
> +{
> + char *str;
> + guid_t uuid;
> + int ret;
> +
> + if ((count < UUID_STRING_LEN) || (count > UUID_STRING_LEN + 1))
> + return -EINVAL;
> +
> + str = kstrndup(buf, count, GFP_KERNEL);
> + if (!str)
> + return -ENOMEM;
> +
> + ret = guid_parse(str, &uuid);
> + kfree(str);
> + if (ret)
> + return ret;
> +
> + ret = vdpasim_remove(&uuid);
> + if (ret)
> + return ret;
> +
> + return count;
> +}
> +
> +static struct kobj_attribute create_attribute = __ATTR_WO(create);
> +static struct kobj_attribute remove_attribute = __ATTR_WO(remove);
> +
> +static struct attribute *attrs[] = {
> + &create_attribute.attr,
> + &remove_attribute.attr,
> + NULL,
> +};
> +
> +static struct attribute_group attr_group = {
> + .attrs = attrs,
> +};
> +
> +static int __init vdpasim_dev_init(void)
> +{
> + struct device *dev;
> + int ret = 0;
> +
> + vdpasim_dev = kzalloc(sizeof(*vdpasim_dev), GFP_KERNEL);
> + if (!vdpasim_dev)
> + return -ENOMEM;
> +
> + idr_init(&vdpasim_dev->vd_idr);
> +
> + vdpasim_dev->vd_class = class_create(THIS_MODULE, VDPASIM_CLASS_NAME);
> +
> + if (IS_ERR(vdpasim_dev->vd_class)) {
> + pr_err("Error: failed to register vdpasim_dev class\n");
> + ret = PTR_ERR(vdpasim_dev->vd_class);
> + goto err_class;
> + }
> +
> + dev = &vdpasim_dev->dev;
> + dev->class = vdpasim_dev->vd_class;
> + dev->release = vdpasim_device_release;
> + dev_set_name(dev, "%s", VDPASIM_NAME);
> +
> + ret = device_register(&vdpasim_dev->dev);
> + if (ret)
> + goto err_register;
> +
> + ret = sysfs_create_group(&vdpasim_dev->dev.kobj, &attr_group);
> + if (ret)
> + goto err_create;
> +
> + vdpasim_dev->devices_kobj = kobject_create_and_add("devices",
> + &dev->kobj);
> + if (!vdpasim_dev->devices_kobj) {
> + ret = -ENOMEM;
> + goto err_devices;
> + }
> +
> + mutex_init(&vsim_list_lock);
> + INIT_LIST_HEAD(&vsim_devices_list);
> +
> + return 0;
> +
> +err_devices:
> + sysfs_remove_group(&vdpasim_dev->dev.kobj, &attr_group);
> +err_create:
> + device_unregister(&vdpasim_dev->dev);
> +err_register:
> + class_destroy(vdpasim_dev->vd_class);
> +err_class:
> + kfree(vdpasim_dev);
> + vdpasim_dev = NULL;
> + return ret;
> +}
> +
> +static void __exit vdpasim_dev_exit(void)
> +{
> + device_unregister(&vdpasim_dev->dev);
> +}
> +
> +module_init(vdpasim_dev_init)
> +module_exit(vdpasim_dev_exit)
> +
> +MODULE_VERSION(DRV_VERSION);
> +MODULE_LICENSE(DRV_LICENSE);
> +MODULE_AUTHOR(DRV_AUTHOR);
> +MODULE_DESCRIPTION(DRV_DESC);