diff options
Diffstat (limited to 'drivers/vdpa/vdpa_sim/vdpa_sim.c')
| -rw-r--r-- | drivers/vdpa/vdpa_sim/vdpa_sim.c | 629 |
1 files changed, 629 insertions, 0 deletions
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c new file mode 100644 index 000000000000..6e8a0cf2fdeb --- /dev/null +++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c @@ -0,0 +1,629 @@ +// 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/dma-mapping.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_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_NAME "vdpasim-netdev" + +static 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 vdpa_device vdpa; + struct vdpasim_virtqueue vqs[2]; + struct work_struct work; + /* spinlock to synchronize virtqueue state */ + spinlock_t lock; + struct virtio_net_config config; + struct vhost_iotlb *iommu; + void *buffer; + u32 status; + u32 generation; + u64 features; +}; + +static struct vdpasim *vdpasim_dev; + +static struct vdpasim *vdpa_to_sim(struct vdpa_device *vdpa) +{ + return container_of(vdpa, struct vdpasim, vdpa); +} + +static struct vdpasim *dev_to_sim(struct device *dev) +{ + struct vdpa_device *vdpa = dev_to_vdpa(dev); + + return vdpa_to_sim(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 *)(uintptr_t)vq->desc_addr, + (struct vring_avail *) + (uintptr_t)vq->driver_addr, + (struct vring_used *) + (uintptr_t)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, NULL, NULL, NULL); +} + +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 vdpasim *vdpasim = dev_to_sim(dev); + 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 vdpasim *vdpasim = dev_to_sim(dev); + 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 vdpasim *vdpasim = dev_to_sim(dev); + 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) { + *dma_addr = DMA_MAPPING_ERROR; + kfree(addr); + addr = NULL; + } 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 vdpasim *vdpasim = dev_to_sim(dev); + struct vhost_iotlb *iommu = vdpasim->iommu; + + vhost_iotlb_del_range(iommu, (u64)dma_addr, + (u64)dma_addr + size - 1); + kfree(phys_to_virt((uintptr_t)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, +}; + +static const struct vdpa_config_ops vdpasim_net_config_ops; + +static struct vdpasim *vdpasim_create(void) +{ + struct virtio_net_config *config; + struct vdpasim *vdpasim; + struct device *dev; + int ret = -ENOMEM; + + vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL, + &vdpasim_net_config_ops); + if (!vdpasim) + goto err_alloc; + + INIT_WORK(&vdpasim->work, vdpasim_work); + spin_lock_init(&vdpasim->lock); + + dev = &vdpasim->vdpa.dev; + dev->coherent_dma_mask = DMA_BIT_MASK(64); + set_dma_ops(dev, &vdpasim_dma_ops); + + vdpasim->iommu = vhost_iotlb_alloc(2048, 0); + if (!vdpasim->iommu) + goto err_iommu; + + vdpasim->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!vdpasim->buffer) + goto err_iommu; + + config = &vdpasim->config; + config->mtu = 1500; + config->status = VIRTIO_NET_S_LINK_UP; + eth_random_addr(config->mac); + + vringh_set_iotlb(&vdpasim->vqs[0].vring, vdpasim->iommu); + vringh_set_iotlb(&vdpasim->vqs[1].vring, vdpasim->iommu); + + vdpasim->vdpa.dma_dev = dev; + ret = vdpa_register_device(&vdpasim->vdpa); + if (ret) + goto err_iommu; + + return vdpasim; + +err_iommu: + put_device(dev); +err_alloc: + return ERR_PTR(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 int vdpasim_dma_map(struct vdpa_device *vdpa, u64 iova, u64 size, + u64 pa, u32 perm) +{ + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); + + return vhost_iotlb_add_range(vdpasim->iommu, iova, + iova + size - 1, pa, perm); +} + +static int vdpasim_dma_unmap(struct vdpa_device *vdpa, u64 iova, u64 size) +{ + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); + + vhost_iotlb_del_range(vdpasim->iommu, iova, iova + size - 1); + + return 0; +} + +static void vdpasim_free(struct vdpa_device *vdpa) +{ + struct vdpasim *vdpasim = vdpa_to_sim(vdpa); + + cancel_work_sync(&vdpasim->work); + kfree(vdpasim->buffer); + if (vdpasim->iommu) + vhost_iotlb_free(vdpasim->iommu); +} + +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, + .dma_map = vdpasim_dma_map, + .dma_unmap = vdpasim_dma_unmap, + .free = vdpasim_free, +}; + +static int __init vdpasim_dev_init(void) +{ + vdpasim_dev = vdpasim_create(); + + if (!IS_ERR(vdpasim_dev)) + return 0; + + return PTR_ERR(vdpasim_dev); +} + +static void __exit vdpasim_dev_exit(void) +{ + struct vdpa_device *vdpa = &vdpasim_dev->vdpa; + + vdpa_unregister_device(vdpa); +} + +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); |