[V5,5/5] vdpasim: vDPA device simulator
diff mbox series

Message ID 20200226060456.27275-6-jasowang@redhat.com
State New
Headers show
Series
  • vDPA support
Related show

Commit Message

Jason Wang Feb. 26, 2020, 6:04 a.m. UTC
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.

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.

Note, there's no management API implemented, a vDPA device will be
registered once the module is probed. We need to handle this in the
future development.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/virtio/vdpa/Kconfig             |  18 +
 drivers/virtio/vdpa/Makefile            |   1 +
 drivers/virtio/vdpa/vdpa_sim/Makefile   |   2 +
 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c | 645 ++++++++++++++++++++++++
 4 files changed, 666 insertions(+)
 create mode 100644 drivers/virtio/vdpa/vdpa_sim/Makefile
 create mode 100644 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c

Comments

kernel test robot Feb. 26, 2020, 11:55 p.m. UTC | #1
Hi Jason,

I love your patch! Yet something to improve:

[auto build test ERROR on linux/master]
[also build test ERROR on linus/master v5.6-rc3]
[cannot apply to vhost/linux-next next-20200226]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Jason-Wang/vDPA-support/20200226-173606
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git f5ae2ea6347a308cfe91f53b53682ce635497d0d
config: um-allyesconfig (attached as .config)
compiler: gcc-7 (Debian 7.5.0-5) 7.5.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=um 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c: In function 'vdpasim_create':
>> drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:335:2: error: implicit declaration of function 'set_dma_ops'; did you mean 'set_groups'? [-Werror=implicit-function-declaration]
     set_dma_ops(dev, &vdpasim_dma_ops);
     ^~~~~~~~~~~
     set_groups
   Cyclomatic Complexity 5 include/linux/compiler.h:__write_once_size
   Cyclomatic Complexity 1 arch/x86/include/asm/bitops.h:fls64
   Cyclomatic Complexity 1 include/linux/log2.h:__ilog2_u64
   Cyclomatic Complexity 1 include/linux/list.h:INIT_LIST_HEAD
   Cyclomatic Complexity 1 arch/um/include/shared/mem.h:to_phys
   Cyclomatic Complexity 1 arch/um/include/shared/mem.h:to_virt
   Cyclomatic Complexity 1 include/linux/spinlock.h:spinlock_check
   Cyclomatic Complexity 1 include/linux/spinlock.h:spin_lock
   Cyclomatic Complexity 1 include/linux/spinlock.h:spin_unlock
   Cyclomatic Complexity 1 include/linux/err.h:ERR_PTR
   Cyclomatic Complexity 1 include/linux/err.h:PTR_ERR
   Cyclomatic Complexity 1 include/linux/slab.h:kmalloc_type
   Cyclomatic Complexity 28 include/linux/slab.h:kmalloc_index
   Cyclomatic Complexity 1 include/linux/slab.h:kmalloc_large
   Cyclomatic Complexity 4 include/linux/slab.h:kmalloc
   Cyclomatic Complexity 1 include/linux/slab.h:kzalloc
   Cyclomatic Complexity 1 include/asm-generic/io.h:virt_to_phys
   Cyclomatic Complexity 1 include/asm-generic/io.h:phys_to_virt
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:dev_to_sim
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpa_to_sim
   Cyclomatic Complexity 4 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:dir_to_perm
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_set_vq_address
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_set_vq_num
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_set_vq_cb
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_get_vq_ready
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_set_vq_state
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_get_vq_state
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_get_vq_align
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_get_features
   Cyclomatic Complexity 2 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_set_features
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_set_config_cb
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_get_vq_num_max
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_get_device_id
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_get_vendor_id
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_get_status
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_set_config
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_get_generation
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_dev_exit
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_dma_map
   Cyclomatic Complexity 3 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_map_page
   Cyclomatic Complexity 3 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_set_map
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_queue_ready
   Cyclomatic Complexity 2 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_set_vq_ready
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_vq_reset
   Cyclomatic Complexity 2 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_reset
   Cyclomatic Complexity 2 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_set_status
   Cyclomatic Complexity 1 include/linux/workqueue.h:queue_work
   Cyclomatic Complexity 1 include/linux/workqueue.h:schedule_work
   Cyclomatic Complexity 2 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_kick_vq
   Cyclomatic Complexity 2 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_get_config
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_dma_unmap
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_unmap_page
   Cyclomatic Complexity 1 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_free_coherent
   Cyclomatic Complexity 3 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_alloc_coherent
   Cyclomatic Complexity 2 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_device_release
   Cyclomatic Complexity 1 include/linux/bottom_half.h:local_bh_disable
   Cyclomatic Complexity 1 include/linux/bottom_half.h:local_bh_enable
   Cyclomatic Complexity 11 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_work
   Cyclomatic Complexity 68 include/asm-generic/getorder.h:get_order
   Cyclomatic Complexity 1 include/linux/etherdevice.h:eth_random_addr
   Cyclomatic Complexity 1 include/linux/err.h:IS_ERR
   Cyclomatic Complexity 7 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_create
   Cyclomatic Complexity 2 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c:vdpasim_dev_init
   cc1: some warnings being treated as errors

vim +335 drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c

   317	
   318	static struct vdpasim *vdpasim_create(void)
   319	{
   320		struct virtio_net_config *config;
   321		struct vdpasim *vdpasim;
   322		struct device *dev;
   323		int ret = -ENOMEM;
   324	
   325		vdpasim = kzalloc(sizeof(*vdpasim), GFP_KERNEL);
   326		if (!vdpasim)
   327			goto err_alloc;
   328	
   329		INIT_WORK(&vdpasim->work, vdpasim_work);
   330		spin_lock_init(&vdpasim->lock);
   331	
   332		dev = &vdpasim->dev;
   333		dev->release = vdpasim_device_release;
   334		dev->coherent_dma_mask = DMA_BIT_MASK(64);
 > 335		set_dma_ops(dev, &vdpasim_dma_ops);
   336		dev_set_name(dev, "%s", VDPASIM_NAME);
   337	
   338		device_initialize(&vdpasim->dev);
   339	
   340		vdpasim->iommu = vhost_iotlb_alloc(2048, 0);
   341		if (!vdpasim->iommu)
   342			goto err_iommu;
   343	
   344		vdpasim->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
   345		if (!vdpasim->buffer)
   346			goto err_iommu;
   347	
   348		config = &vdpasim->config;
   349		config->mtu = 1500;
   350		config->status = VIRTIO_NET_S_LINK_UP;
   351		eth_random_addr(config->mac);
   352	
   353		vringh_set_iotlb(&vdpasim->vqs[0].vring, vdpasim->iommu);
   354		vringh_set_iotlb(&vdpasim->vqs[1].vring, vdpasim->iommu);
   355	
   356		ret = device_add(&vdpasim->dev);
   357		if (ret)
   358			goto err_iommu;
   359	
   360		vdpasim->vdpa = vdpa_alloc_device(dev, dev, &vdpasim_net_config_ops);
   361		if (IS_ERR(vdpasim->vdpa))
   362			goto err_vdpa;
   363	
   364		ret = vdpa_register_device(vdpasim->vdpa);
   365		if (ret)
   366			goto err_register;
   367	
   368		return vdpasim;
   369	
   370	err_register:
   371		put_device(&vdpasim->vdpa->dev);
   372	err_vdpa:
   373		device_del(&vdpasim->dev);
   374		goto err_alloc;
   375	err_iommu:
   376		put_device(&vdpasim->dev);
   377	err_alloc:
   378		return ERR_PTR(ret);
   379	}
   380	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

Patch
diff mbox series

diff --git a/drivers/virtio/vdpa/Kconfig b/drivers/virtio/vdpa/Kconfig
index 9aac904a9515..9e7dc95e0c89 100644
--- a/drivers/virtio/vdpa/Kconfig
+++ b/drivers/virtio/vdpa/Kconfig
@@ -6,3 +6,21 @@  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
+	depends on RUNTIME_TESTING_MENU
+	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..3814af8e097b 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/
diff --git a/drivers/virtio/vdpa/vdpa_sim/Makefile b/drivers/virtio/vdpa/vdpa_sim/Makefile
new file mode 100644
index 000000000000..b40278f65e04
--- /dev/null
+++ b/drivers/virtio/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/virtio/vdpa/vdpa_sim/vdpa_sim.c b/drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c
new file mode 100644
index 000000000000..c728d49a88f6
--- /dev/null
+++ b/drivers/virtio/vdpa/vdpa_sim/vdpa_sim.c
@@ -0,0 +1,645 @@ 
+// 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_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 vdpasim_virtqueue vqs[2];
+	struct work_struct work;
+	/* spinlock to synchronize virtqueue state */
+	spinlock_t lock;
+	struct vdpa_device *vdpa;
+	struct device dev;
+	struct virtio_net_config config;
+	struct vhost_iotlb *iommu;
+	void *buffer;
+	u32 status;
+	u32 generation;
+	u64 features;
+};
+
+struct vdpasim *vdpasim_dev;
+
+static struct vdpasim *dev_to_sim(struct device *dev)
+{
+	return container_of(dev, struct vdpasim, dev);
+}
+
+static struct vdpasim *vdpa_to_sim(struct vdpa_device *vdpa)
+{
+	struct device *d = &vdpa->dev;
+
+	return dev_to_sim(d->parent);
+}
+
+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, 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 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 void vdpasim_device_release(struct device *dev)
+{
+	struct vdpasim *vdpasim = dev_to_sim(dev);
+
+	cancel_work_sync(&vdpasim->work);
+	kfree(vdpasim->buffer);
+	if (vdpasim->iommu)
+		vhost_iotlb_free(vdpasim->iommu);
+	kfree(vdpasim);
+}
+
+static struct vdpasim *vdpasim_create(void)
+{
+	struct virtio_net_config *config;
+	struct vdpasim *vdpasim;
+	struct device *dev;
+	int ret = -ENOMEM;
+
+	vdpasim = kzalloc(sizeof(*vdpasim), GFP_KERNEL);
+	if (!vdpasim)
+		goto err_alloc;
+
+	INIT_WORK(&vdpasim->work, vdpasim_work);
+	spin_lock_init(&vdpasim->lock);
+
+	dev = &vdpasim->dev;
+	dev->release = vdpasim_device_release;
+	dev->coherent_dma_mask = DMA_BIT_MASK(64);
+	set_dma_ops(dev, &vdpasim_dma_ops);
+	dev_set_name(dev, "%s", VDPASIM_NAME);
+
+	device_initialize(&vdpasim->dev);
+
+	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);
+
+	ret = device_add(&vdpasim->dev);
+	if (ret)
+		goto err_iommu;
+
+	vdpasim->vdpa = vdpa_alloc_device(dev, dev, &vdpasim_net_config_ops);
+	if (IS_ERR(vdpasim->vdpa))
+		goto err_vdpa;
+
+	ret = vdpa_register_device(vdpasim->vdpa);
+	if (ret)
+		goto err_register;
+
+	return vdpasim;
+
+err_register:
+	put_device(&vdpasim->vdpa->dev);
+err_vdpa:
+	device_del(&vdpasim->dev);
+	goto err_alloc;
+err_iommu:
+	put_device(&vdpasim->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 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,
+};
+
+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);
+	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);