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-rw-r--r--drivers/vdpa/vdpa_sim/Makefile2
-rw-r--r--drivers/vdpa/vdpa_sim/vdpa_sim.c629
2 files changed, 631 insertions, 0 deletions
diff --git a/drivers/vdpa/vdpa_sim/Makefile b/drivers/vdpa/vdpa_sim/Makefile
new file mode 100644
index 000000000000..b40278f65e04
--- /dev/null
+++ b/drivers/vdpa/vdpa_sim/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_VDPA_SIM) += vdpa_sim.o
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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-21 13:54:00 +0100