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// SPDX-License-Identifier: GPL-2.0-only
/*
* VDPA simulator for block device.
*
* Copyright (c) 2020, NVIDIA CORPORATION. All rights reserved.
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/blkdev.h>
#include <linux/vringh.h>
#include <linux/vdpa.h>
#include <uapi/linux/virtio_blk.h>
#include "vdpa_sim.h"
#define DRV_VERSION "0.1"
#define DRV_AUTHOR "Max Gurtovoy <mgurtovoy@nvidia.com>"
#define DRV_DESC "vDPA Device Simulator for block device"
#define DRV_LICENSE "GPL v2"
#define VDPASIM_BLK_FEATURES (VDPASIM_FEATURES | \
(1ULL << VIRTIO_BLK_F_SIZE_MAX) | \
(1ULL << VIRTIO_BLK_F_SEG_MAX) | \
(1ULL << VIRTIO_BLK_F_BLK_SIZE) | \
(1ULL << VIRTIO_BLK_F_TOPOLOGY) | \
(1ULL << VIRTIO_BLK_F_MQ))
#define VDPASIM_BLK_CAPACITY 0x40000
#define VDPASIM_BLK_SIZE_MAX 0x1000
#define VDPASIM_BLK_SEG_MAX 32
#define VDPASIM_BLK_VQ_NUM 1
static struct vdpasim *vdpasim_blk_dev;
static void vdpasim_blk_work(struct work_struct *work)
{
struct vdpasim *vdpasim = container_of(work, struct vdpasim, work);
u8 status = VIRTIO_BLK_S_OK;
int i;
spin_lock(&vdpasim->lock);
if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
goto out;
for (i = 0; i < VDPASIM_BLK_VQ_NUM; i++) {
struct vdpasim_virtqueue *vq = &vdpasim->vqs[i];
if (!vq->ready)
continue;
while (vringh_getdesc_iotlb(&vq->vring, &vq->out_iov,
&vq->in_iov, &vq->head,
GFP_ATOMIC) > 0) {
int write;
vq->in_iov.i = vq->in_iov.used - 1;
write = vringh_iov_push_iotlb(&vq->vring, &vq->in_iov,
&status, 1);
if (write <= 0)
break;
/* Make sure data is wrote before advancing index */
smp_wmb();
vringh_complete_iotlb(&vq->vring, vq->head, write);
/* Make sure used is visible before rasing the interrupt. */
smp_wmb();
local_bh_disable();
if (vringh_need_notify_iotlb(&vq->vring) > 0)
vringh_notify(&vq->vring);
local_bh_enable();
}
}
out:
spin_unlock(&vdpasim->lock);
}
static void vdpasim_blk_get_config(struct vdpasim *vdpasim, void *config)
{
struct virtio_blk_config *blk_config = config;
memset(config, 0, sizeof(struct virtio_blk_config));
blk_config->capacity = cpu_to_vdpasim64(vdpasim, VDPASIM_BLK_CAPACITY);
blk_config->size_max = cpu_to_vdpasim32(vdpasim, VDPASIM_BLK_SIZE_MAX);
blk_config->seg_max = cpu_to_vdpasim32(vdpasim, VDPASIM_BLK_SEG_MAX);
blk_config->num_queues = cpu_to_vdpasim16(vdpasim, VDPASIM_BLK_VQ_NUM);
blk_config->min_io_size = cpu_to_vdpasim16(vdpasim, 1);
blk_config->opt_io_size = cpu_to_vdpasim32(vdpasim, 1);
blk_config->blk_size = cpu_to_vdpasim32(vdpasim, SECTOR_SIZE);
}
static int __init vdpasim_blk_init(void)
{
struct vdpasim_dev_attr dev_attr = {};
int ret;
dev_attr.id = VIRTIO_ID_BLOCK;
dev_attr.supported_features = VDPASIM_BLK_FEATURES;
dev_attr.nvqs = VDPASIM_BLK_VQ_NUM;
dev_attr.config_size = sizeof(struct virtio_blk_config);
dev_attr.get_config = vdpasim_blk_get_config;
dev_attr.work_fn = vdpasim_blk_work;
dev_attr.buffer_size = PAGE_SIZE;
vdpasim_blk_dev = vdpasim_create(&dev_attr);
if (IS_ERR(vdpasim_blk_dev)) {
ret = PTR_ERR(vdpasim_blk_dev);
goto out;
}
ret = vdpa_register_device(&vdpasim_blk_dev->vdpa, VDPASIM_BLK_VQ_NUM);
if (ret)
goto put_dev;
return 0;
put_dev:
put_device(&vdpasim_blk_dev->vdpa.dev);
out:
return ret;
}
static void __exit vdpasim_blk_exit(void)
{
struct vdpa_device *vdpa = &vdpasim_blk_dev->vdpa;
vdpa_unregister_device(vdpa);
}
module_init(vdpasim_blk_init)
module_exit(vdpasim_blk_exit)
MODULE_VERSION(DRV_VERSION);
MODULE_LICENSE(DRV_LICENSE);
MODULE_AUTHOR(DRV_AUTHOR);
MODULE_DESCRIPTION(DRV_DESC);
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