[dpdk-dev] [PATCH v4 11/12] virtio: Add QTest support for virtio-net PMD

[Tetsuya Mukawa <mukawa@igel.co.jp>]

The patch adds a new virtio-net PMD configuration that allows the PMD to
work on host as if the PMD is in VM.
Here is new configuration for virtio-net PMD.
 - CONFIG_RTE_VIRTIO_VDEV_QTEST
To use this mode, EAL needs map all hugepages as one file. Also the file
should be mapped between (1 << 31) and (1 << 44). And start address
should be aligned by EAL memory size.

To allocate like above, use below options.
 --single-file
 --range-virtaddr=0x80000000-0x100000000000
 --align-memsize
If a free region cannot be found, EAL will return error.

To prepare virtio-net device on host, the users need to invoke QEMU
process in special QTest mode. This mode is mainly used for testing QEMU
devices from outer process. In this mode, no guest runs.
Here is QEMU command line.

 $ qemu-system-x86_64 \
     -machine pc-i440fx-1.4,accel=qtest \
     -display none -qtest-log /dev/null \
     -qtest unix:/tmp/socket,server \
     -netdev type=tap,script=/etc/qemu-ifup,id=net0,queues=1 \
     -device
virtio-net-pci,netdev=net0,mq=on,disable-modern=false,addr=3 \
     -chardev socket,id=chr1,path=/tmp/ivshmem,server \
     -device ivshmem,size=1G,chardev=chr1,vectors=1,addr=4

 * Should use QEMU-2.5.1, or above.
 * QEMU process is needed per port.
 * virtio-1.0 device are only supported.
 * The vhost backends like vhost-net and vhost-user can be specified.
 * In most cases, just using above command is enough, but you can also
   specify other QEMU virtio-net options like mac address.
 * Only checked "pc-i440fx-1.4" machine, but may work with other
   machines.
 * Should not add "--enable-kvm" to QEMU command line.

After invoking QEMU, the PMD can connect to QEMU process using unix
domain sockets. Over these sockets, virtio-net, ivshmem and piix3
device in QEMU are probed by the PMD.
Here is example of command line.

 $ testpmd -c f -n 1 -m 1024 --no-pci --single-file \
      --range-virtaddr=0x80000000-0x100000000000 --align-memsize \
      --vdev="eth_qtest_virtio0,qtest=/tmp/socket,ivshmem=/tmp/ivshmem"\
      -- --disable-hw-vlan --txqflags=0xf00 -i

Please specify same unix domain sockets and memory size in both QEMU
and DPDK command lines like above.
The share memory size should be power of 2, because ivshmem only
accepts such memory size.

Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
---
 drivers/net/virtio/qtest.h         |  55 +++++
 drivers/net/virtio/virtio_ethdev.c | 457 ++++++++++++++++++++++++++++++++++++-
 2 files changed, 501 insertions(+), 11 deletions(-)

diff --git a/drivers/net/virtio/qtest.h b/drivers/net/virtio/qtest.h
index 46b9ee6..421e62c 100644
--- a/drivers/net/virtio/qtest.h
+++ b/drivers/net/virtio/qtest.h
@@ -35,5 +35,60 @@
 #define _VIRTIO_QTEST_H_
 
 #define QTEST_DRV_NAME		        "eth_qtest_virtio"
+#define QTEST_DEVICE_NUM                3
+
+#include <linux/pci_regs.h>
+
+/* Device information */
+#define VIRTIO_NET_DEVICE_ID            0x1000
+#define VIRTIO_NET_VENDOR_ID            0x1af4
+#define VIRTIO_NET_IRQ_NUM              10
+#define IVSHMEM_DEVICE_ID               0x1110
+#define IVSHMEM_VENDOR_ID               0x1af4
+#define PIIX3_DEVICE_ID                 0x7000
+#define PIIX3_VENDOR_ID                 0x8086
+
+/* ------------------------------------------------------------
+ * IO port mapping of qtest guest
+ * ------------------------------------------------------------
+ * 0x0000 - 0xbfff : not used
+ * 0xc000 - 0xc03f : virtio-net(BAR0)
+ * 0xc040 - 0xffff : not used
+ *
+ * ------------------------------------------------------------
+ * Memory mapping of qtest quest
+ * ------------------------------------------------------------
+ * 0x00000000_00000000 - 0x00000000_3fffffff : not used
+ * 0x00000000_40000000 - 0x00000000_40000fff : virtio-net(BAR1)
+ * 0x00000000_40001000 - 0x00000000_40ffffff : not used
+ * 0x00000000_41000000 - 0x00000000_417fffff : virtio-net(BAR4)
+ * 0x00000000_41800000 - 0x00000000_41ffffff : not used
+ * 0x00000000_42000000 - 0x00000000_420000ff : ivshmem(BAR0)
+ * 0x00000000_42000100 - 0x00000000_42ffffff : not used
+ * 0x00000000_80000000 - 0xffffffff_ffffffff : ivshmem(BAR2)
+ *
+ * We can only specify start address of a region. The region size
+ * will be defined by the device implementation in QEMU.
+ * The size will be pow of 2 according to the PCI specification.
+ * Also, the region start address should be aligned by region size.
+ *
+ * BAR2 of ivshmem will be used to mmap DPDK application memory.
+ * So this address will be dynamically changed, but not to overlap
+ * others, it should be mmaped between above addresses. Such allocation
+ * is done by EAL. Check rte_eal_get_free_region() also.
+ */
+#define VIRTIO_NET_IO_START             0xc000
+#define VIRTIO_NET_MEMORY1_START	0x40000000
+#define VIRTIO_NET_MEMORY2_START	0x41000000
+#define IVSHMEM_MEMORY_START            0x42000000
+
+static inline struct rte_pci_id
+qtest_get_pci_id_of_virtio_net(void)
+{
+	struct rte_pci_id id =  {VIRTIO_NET_DEVICE_ID,
+		VIRTIO_NET_VENDOR_ID, PCI_ANY_ID, PCI_ANY_ID};
+
+	return id;
+}
 
 #endif /* _VIRTIO_QTEST_H_ */
diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index 747596d..4e454db 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -60,6 +60,10 @@
 #include "virtqueue.h"
 #include "virtio_rxtx.h"
 
+#ifdef RTE_VIRTIO_VDEV_QTEST
+#include "qtest.h"
+#include "qtest_utils.h"
+#endif
 
 static int eth_virtio_dev_init(struct rte_eth_dev *eth_dev);
 static int eth_virtio_dev_uninit(struct rte_eth_dev *eth_dev);
@@ -387,7 +391,7 @@ int virtio_dev_queue_setup(struct rte_eth_dev *dev,
 			return -ENOMEM;
 		}
 	}
-#ifdef RTE_VIRTIO_VDEV
+#if defined(RTE_VIRTIO_VDEV) || defined(RTE_VIRTIO_VDEV_QTEST)
 	else
 		vq->vq_ring_mem = (phys_addr_t)mz->addr; /* Use vaddr!!! */
 #endif
@@ -431,7 +435,7 @@ int virtio_dev_queue_setup(struct rte_eth_dev *dev,
 
 		if (virtio_dev_check(dev, RTE_ETH_DEV_PCI, NULL, 0))
 			vq->virtio_net_hdr_mem = mz->phys_addr;
-#ifdef RTE_VIRTIO_VDEV
+#if defined(RTE_VIRTIO_VDEV) || defined(RTE_VIRTIO_VDEV_QTEST)
 		else
 			vq->virtio_net_hdr_mem = (phys_addr_t)mz->addr;
 #endif
@@ -441,7 +445,7 @@ int virtio_dev_queue_setup(struct rte_eth_dev *dev,
 
 	if (virtio_dev_check(dev, RTE_ETH_DEV_PCI, NULL, 0))
 		vq->offset = offsetof(struct rte_mbuf, buf_physaddr);
-#ifdef RTE_VIRTIO_VDEV
+#if defined(RTE_VIRTIO_VDEV) || defined(RTE_VIRTIO_VDEV_QTEST)
 	else
 		vq->offset = offsetof(struct rte_mbuf, buf_addr);
 #endif
@@ -999,6 +1003,23 @@ virtio_interrupt_handler(__rte_unused struct rte_intr_handle *handle,
 	isr = vtpci_isr(hw);
 	PMD_DRV_LOG(INFO, "interrupt status = %#x", isr);
 
+#ifdef RTE_VIRTIO_VDEV_QTEST
+	if (virtio_dev_check(dev, RTE_ETH_DEV_VIRTUAL, QTEST_DRV_NAME, 0)) {
+		if (qtest_intr_enable(hw->qsession) < 0)
+			PMD_DRV_LOG(ERR, "interrupt enable failed");
+		/*
+		 * If last qtest message is interrupt, 'isr' will be 0
+		 * becasue socket has been closed already.
+		 * But still we want to notice this event to EAL.
+		 * So just ignore isr value.
+		 */
+		if (virtio_dev_link_update(dev, 0) == 0)
+			_rte_eth_dev_callback_process(dev,
+					RTE_ETH_EVENT_INTR_LSC);
+		return;
+	}
+#endif
+
 	if (virtio_dev_check(dev, RTE_ETH_DEV_PCI, NULL, 0))
 		if (rte_intr_enable(&dev->pci_dev->intr_handle) < 0)
 			PMD_DRV_LOG(ERR, "interrupt enable failed");
@@ -1058,6 +1079,13 @@ eth_virtio_dev_init(struct rte_eth_dev *eth_dev)
 		if (vtpci_init(eth_dev, hw) < 0)
 			return -1;
 	}
+#ifdef RTE_VIRTIO_VDEV_QTEST
+	else if (virtio_dev_check(eth_dev,
+				RTE_ETH_DEV_VIRTUAL, QTEST_DRV_NAME, 0)) {
+		if (vtpci_init(eth_dev, hw) < 0)
+			return -1;
+	}
+#endif
 
 	/* Reset the device although not necessary at startup */
 	vtpci_reset(hw);
@@ -1077,6 +1105,13 @@ eth_virtio_dev_init(struct rte_eth_dev *eth_dev)
 
 		rte_eth_copy_pci_info(eth_dev, pci_dev);
 	}
+#ifdef RTE_VIRTIO_VDEV_QTEST
+	else if (virtio_dev_check(eth_dev,
+				RTE_ETH_DEV_VIRTUAL, QTEST_DRV_NAME, 0)) {
+		if (!vtpci_with_feature(hw, VIRTIO_NET_F_STATUS))
+			pci_dev->driver->drv_flags &= ~RTE_PCI_DRV_INTR_LSC;
+	}
+#endif
 
 	rx_func_get(eth_dev);
 
@@ -1165,6 +1200,26 @@ eth_virtio_dev_init(struct rte_eth_dev *eth_dev)
 						   virtio_interrupt_handler,
 						   eth_dev);
 	}
+#ifdef RTE_VIRTIO_VDEV_QTEST
+	else if (virtio_dev_check(eth_dev, RTE_ETH_DEV_VIRTUAL,
+				QTEST_DRV_NAME, 0)) {
+		struct rte_pci_id id;
+
+		id = qtest_get_pci_id_of_virtio_net();
+		RTE_SET_USED(id);
+
+		PMD_INIT_LOG(DEBUG, "port %d vendorID=0x%x deviceID=0x%x",
+				eth_dev->data->port_id,
+				id.vendor_id, id.device_id);
+
+		/* Setup interrupt callback  */
+		if (virtio_dev_check(eth_dev, RTE_ETH_DEV_VIRTUAL,
+					NULL, RTE_ETH_DEV_INTR_LSC))
+			qtest_intr_callback_register(hw->qsession,
+					virtio_interrupt_handler, eth_dev);
+	}
+#endif
+
 	virtio_dev_cq_start(eth_dev);
 
 	return 0;
@@ -1202,7 +1257,15 @@ eth_virtio_dev_uninit(struct rte_eth_dev *eth_dev)
 					     virtio_interrupt_handler,
 					     eth_dev);
 
-	rte_eal_pci_unmap_device(pci_dev);
+#ifdef RTE_VIRTIO_VDEV_QTEST
+	else if (virtio_dev_check(eth_dev, RTE_ETH_DEV_VIRTUAL,
+				QTEST_DRV_NAME, RTE_ETH_DEV_INTR_LSC))
+		qtest_intr_callback_unregister(hw->qsession,
+				virtio_interrupt_handler, eth_dev);
+#endif
+
+	if (virtio_dev_check(eth_dev, RTE_ETH_DEV_PCI, NULL, 0))
+		rte_eal_pci_unmap_device(pci_dev);
 
 	PMD_INIT_LOG(DEBUG, "dev_uninit completed");
 
@@ -1284,16 +1347,34 @@ virtio_dev_start(struct rte_eth_dev *dev)
 
 	/* check if lsc interrupt feature is enabled */
 	if (dev->data->dev_conf.intr_conf.lsc) {
-		if (!virtio_dev_check(dev, RTE_ETH_DEV_PCI,
-					NULL, RTE_PCI_DRV_INTR_LSC)) {
+		int pdev_has_lsc = 0, vdev_has_lsc = 0;
+
+		pdev_has_lsc = virtio_dev_check(dev, RTE_ETH_DEV_PCI,
+				NULL, RTE_PCI_DRV_INTR_LSC);
+#ifdef RTE_VIRTIO_VDEV_QTEST
+		vdev_has_lsc = virtio_dev_check(dev, RTE_ETH_DEV_VIRTUAL,
+				QTEST_DRV_NAME, RTE_ETH_DEV_INTR_LSC);
+#endif
+
+		if ((!pdev_has_lsc) && (!vdev_has_lsc)) {
 			PMD_DRV_LOG(ERR, "link status not supported by host");
 			return -ENOTSUP;
 		}
 
-		if (rte_intr_enable(&dev->pci_dev->intr_handle) < 0) {
-			PMD_DRV_LOG(ERR, "interrupt enable failed");
-			return -EIO;
+		if (pdev_has_lsc) {
+			if (rte_intr_enable(&dev->pci_dev->intr_handle) < 0) {
+				PMD_DRV_LOG(ERR, "interrupt enable failed");
+				return -EIO;
+			}
 		}
+#ifdef RTE_VIRTIO_VDEV_QTEST
+		else if (vdev_has_lsc) {
+			if (qtest_intr_enable(hw->qsession) < 0) {
+				PMD_DRV_LOG(ERR, "interrupt enable failed");
+				return -EIO;
+			}
+		}
+#endif
 	}
 
 	/* Initialize Link state */
@@ -1387,11 +1468,20 @@ static void
 virtio_dev_stop(struct rte_eth_dev *dev)
 {
 	struct rte_eth_link link;
+	struct virtio_hw *hw = dev->data->dev_private;
 
 	PMD_INIT_LOG(DEBUG, "stop");
+	RTE_SET_USED(hw);
 
-	if (dev->data->dev_conf.intr_conf.lsc)
-		rte_intr_disable(&dev->pci_dev->intr_handle);
+	if (dev->data->dev_conf.intr_conf.lsc) {
+		if (virtio_dev_check(dev, RTE_ETH_DEV_PCI, NULL, 0))
+			rte_intr_disable(&dev->pci_dev->intr_handle);
+#ifdef RTE_VIRTIO_VDEV_QTEST
+		else if (virtio_dev_check(dev, RTE_ETH_DEV_VIRTUAL,
+					QTEST_DRV_NAME, 0))
+			qtest_intr_disable(hw->qsession);
+#endif
+	}
 
 	memset(&link, 0, sizeof(link));
 	virtio_dev_atomic_write_link_status(dev, &link);
@@ -1628,3 +1718,348 @@ static struct rte_driver rte_cvio_driver = {
 PMD_REGISTER_DRIVER(rte_cvio_driver);
 
 #endif
+
+#ifdef RTE_VIRTIO_VDEV_QTEST
+
+#define ETH_VIRTIO_NET_ARG_QTEST_PATH           "qtest"
+#define ETH_VIRTIO_NET_ARG_IVSHMEM_PATH         "ivshmem"
+#define ETH_VIRTIO_NET_ARG_VIRTIO_NET_ADDR      "virtio-net-addr"
+#define ETH_VIRTIO_NET_ARG_IVSHMEM_ADDR         "ivshmem-addr"
+#define ETH_VIRTIO_NET_ARG_PIIX3_ADDR           "piix3-addr"
+
+static const char *valid_qtest_args[] = {
+	ETH_VIRTIO_NET_ARG_QTEST_PATH,
+	ETH_VIRTIO_NET_ARG_IVSHMEM_PATH,
+	ETH_VIRTIO_NET_ARG_VIRTIO_NET_ADDR,
+	ETH_VIRTIO_NET_ARG_IVSHMEM_ADDR,
+	ETH_VIRTIO_NET_ARG_PIIX3_ADDR,
+	NULL
+};
+
+static int
+get_socket_path_arg(const char *key __rte_unused,
+		const char *value, void *extra_args)
+{
+	char **p;
+
+	if ((value == NULL) || (extra_args == NULL))
+		return -EINVAL;
+
+	p = extra_args;
+	*p = strdup(value);
+
+	if (*p == NULL)
+		return -1;
+
+	return 0;
+}
+
+static int
+get_pci_addr_arg(const char *key __rte_unused,
+		const char *value, void *extra_args)
+{
+	struct rte_pci_addr *addr = extra_args;
+
+	if ((value == NULL) || (extra_args == NULL))
+		return -EINVAL;
+
+	if (eal_parse_pci_DomBDF(value, addr) != 0)
+		return -1;
+
+	if (addr->domain != 0)
+		return -1;
+
+	return 0;
+}
+
+static int
+virtio_net_eth_dev_free(struct rte_eth_dev *eth_dev)
+{
+	struct virtio_hw *hw;
+	int ret;
+
+	ret = rte_eth_dev_release_port(eth_dev);
+	if (ret < 0) {
+		PMD_INIT_LOG(ERR, "cannot release a port\n");
+		return -1;
+	}
+
+	hw = eth_dev->data->dev_private;
+	rte_free(hw);
+
+	return 0;
+}
+
+static struct rte_eth_dev *
+virtio_net_eth_dev_alloc(const char *name)
+{
+	struct rte_eth_dev *eth_dev;
+	struct rte_eth_dev_data *data;
+	struct virtio_hw *hw;
+	int ret;
+
+	eth_dev = rte_eth_dev_allocate(name, RTE_ETH_DEV_VIRTUAL);
+	if (eth_dev == NULL) {
+		PMD_INIT_LOG(ERR, "cannot alloc a port\n");
+		return NULL;
+	}
+
+	data = eth_dev->data;
+
+	hw = rte_zmalloc(NULL, sizeof(*hw), 0);
+	if (hw == NULL) {
+		PMD_INIT_LOG(ERR, "malloc virtio_hw failed\n");
+		ret = rte_eth_dev_release_port(eth_dev);
+		if (ret < 0)
+			rte_panic("cannot release a port");
+		return NULL;
+	}
+
+	data->dev_private = hw;
+	eth_dev->driver = &rte_virtio_pmd;
+	return eth_dev;
+}
+
+static int
+virtio_net_eth_pmd_parse_socket_path(struct rte_kvargs *kvlist,
+		const char *option, char **path)
+{
+	int ret;
+
+	if (rte_kvargs_count(kvlist, option) == 1) {
+		ret = rte_kvargs_process(kvlist, option,
+				&get_socket_path_arg, path);
+		if (ret != 0) {
+			PMD_INIT_LOG(ERR,
+					"Failed to connect to %s socket", option);
+			return -1;
+		}
+	} else {
+		PMD_INIT_LOG(ERR, "No argument specified for %s", option);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int
+virtio_net_eth_pmd_parse_pci_addr(struct rte_kvargs *kvlist,
+		const char *option, struct rte_pci_addr *addr,
+		struct rte_pci_addr *default_addr)
+{
+	int ret;
+
+	if (rte_kvargs_count(kvlist, option) == 1) {
+		ret = rte_kvargs_process(kvlist, option,
+				&get_pci_addr_arg, addr);
+		if (ret != 0) {
+			PMD_INIT_LOG(ERR,
+					"Specified invalid address in '%s'", option);
+			return -1;
+		}
+	} else
+		/* copy default pci address */
+		*addr = *default_addr;
+
+	return 0;
+}
+
+static int
+virtio_prepare_target_devices(struct qtest_pci_device *devices,
+			struct rte_kvargs *kvlist)
+{
+	struct qtest_pci_device *virtio_net, *ivshmem, *piix3;
+	struct rte_pci_addr default_addr;
+	const struct rte_memseg *ms;
+	int ret;
+
+	ms = rte_eal_get_physmem_layout();
+	/* if EAL memory size isn't pow of 2, ivshmem will refuse it */
+	if ((ms[0].len & (ms[0].len - 1)) != 0) {
+		PMD_DRV_LOG(ERR, "memory size must be power of 2\n");
+		return -1;
+	}
+
+	virtio_net = &devices[0];
+	ivshmem = &devices[1];
+	piix3 = &devices[2];
+
+	virtio_net->name = "virtio-net";
+	virtio_net->device_id = VIRTIO_NET_DEVICE_ID;
+	virtio_net->vendor_id = VIRTIO_NET_VENDOR_ID;
+	virtio_net->init = qtest_init_pci_device;
+	virtio_net->bar[0].addr = PCI_BASE_ADDRESS_0;
+	virtio_net->bar[0].type = QTEST_PCI_BAR_IO;
+	virtio_net->bar[0].region_start = VIRTIO_NET_IO_START;
+	virtio_net->bar[1].addr = PCI_BASE_ADDRESS_1;
+	virtio_net->bar[1].type = QTEST_PCI_BAR_MEMORY_32;
+	virtio_net->bar[1].region_start = VIRTIO_NET_MEMORY1_START;
+	virtio_net->bar[4].addr = PCI_BASE_ADDRESS_4;
+	virtio_net->bar[4].type = QTEST_PCI_BAR_MEMORY_64;
+	virtio_net->bar[4].region_start = VIRTIO_NET_MEMORY2_START;
+
+	ivshmem->name = "ivshmem";
+	ivshmem->device_id = IVSHMEM_DEVICE_ID;
+	ivshmem->vendor_id = IVSHMEM_VENDOR_ID;
+	ivshmem->init = qtest_init_pci_device;
+	ivshmem->bar[0].addr = PCI_BASE_ADDRESS_0;
+	ivshmem->bar[0].type = QTEST_PCI_BAR_MEMORY_32;
+	ivshmem->bar[0].region_start = IVSHMEM_MEMORY_START;
+	ivshmem->bar[2].addr = PCI_BASE_ADDRESS_2;
+	ivshmem->bar[2].type = QTEST_PCI_BAR_MEMORY_64;
+	/* In host mode, only one memory segment is vaild */
+	ivshmem->bar[2].region_start = (uint64_t)ms[0].addr;
+
+	/* piix3 is needed to route irqs from virtio-net to ioapic */
+	piix3->name = "piix3";
+	piix3->device_id = PIIX3_DEVICE_ID;
+	piix3->vendor_id = PIIX3_VENDOR_ID;
+	piix3->init = qtest_init_piix3_device;
+
+	/*
+	 * Set pci addresses specified by command line.
+	 * QTest utils will only check specified pci address.
+	 * If it's wrong, a target device won't be found.
+	 */
+	default_addr.domain = 0;
+	default_addr.bus = 0;
+	default_addr.function = 0;
+
+	default_addr.devid = 3;
+	ret = virtio_net_eth_pmd_parse_pci_addr(kvlist,
+			ETH_VIRTIO_NET_ARG_VIRTIO_NET_ADDR,
+			&virtio_net->specified_addr, &default_addr);
+	if (ret < 0)
+		return -1;
+
+	default_addr.devid = 4;
+	ret = virtio_net_eth_pmd_parse_pci_addr(kvlist,
+			ETH_VIRTIO_NET_ARG_IVSHMEM_ADDR,
+			&ivshmem->specified_addr, &default_addr);
+	if (ret < 0)
+		return -1;
+
+	default_addr.devid = 1;
+	ret = virtio_net_eth_pmd_parse_pci_addr(kvlist,
+			ETH_VIRTIO_NET_ARG_PIIX3_ADDR,
+			&piix3->specified_addr, &default_addr);
+	if (ret < 0)
+		return -1;
+
+	return 0;
+}
+/*
+ * Initialization when "CONFIG_RTE_VIRTIO_VDEV_QTEST" is enabled.
+ */
+static int
+rte_qtest_virtio_pmd_init(const char *name, const char *params)
+{
+	struct rte_kvargs *kvlist;
+	struct virtio_hw *hw = NULL;
+	struct rte_eth_dev *eth_dev = NULL;
+	char *qtest_path = NULL, *ivshmem_path = NULL;
+	struct qtest_pci_device devices[QTEST_DEVICE_NUM];
+	int ret;
+
+	if (params == NULL || params[0] == '\0')
+		return -EINVAL;
+
+	kvlist = rte_kvargs_parse(params, valid_qtest_args);
+	if (kvlist == NULL) {
+		PMD_INIT_LOG(ERR, "error when parsing param");
+		return -EFAULT;
+	}
+
+	ret = virtio_net_eth_pmd_parse_socket_path(kvlist,
+			ETH_VIRTIO_NET_ARG_IVSHMEM_PATH, &ivshmem_path);
+	if (ret < 0)
+		goto error;
+
+	ret = virtio_net_eth_pmd_parse_socket_path(kvlist,
+			ETH_VIRTIO_NET_ARG_QTEST_PATH, &qtest_path);
+	if (ret < 0)
+		goto error;
+
+	ret = virtio_prepare_target_devices(devices, kvlist);
+	if (ret < 0)
+		goto error;
+
+	eth_dev = virtio_net_eth_dev_alloc(name);
+	if (eth_dev == NULL)
+		goto error;
+
+	hw = eth_dev->data->dev_private;
+	hw->qsession = qtest_vdev_init(qtest_path, ivshmem_path,
+			VIRTIO_NET_IRQ_NUM, devices, QTEST_DEVICE_NUM);
+	if (hw->qsession == NULL)
+		goto error;
+
+	/* originally, this will be called in rte_eal_pci_probe() */
+	ret = eth_virtio_dev_init(eth_dev);
+	if (ret < 0)
+		goto error;
+
+	eth_dev->driver = NULL;
+	eth_dev->data->dev_flags |= RTE_ETH_DEV_DETACHABLE;
+	eth_dev->data->kdrv = RTE_KDRV_NONE;
+	eth_dev->data->drv_name = QTEST_DRV_NAME;
+
+	free(qtest_path);
+	free(ivshmem_path);
+	rte_kvargs_free(kvlist);
+	return 0;
+
+error:
+	if (hw != NULL && hw->qsession != NULL)
+		qtest_vdev_uninit(hw->qsession);
+	if (eth_dev)
+		virtio_net_eth_dev_free(eth_dev);
+	if (qtest_path)
+		free(qtest_path);
+	if (ivshmem_path)
+		free(ivshmem_path);
+	rte_kvargs_free(kvlist);
+	return -EFAULT;
+}
+
+/*
+ * Finalization when "CONFIG_RTE_VIRTIO_VDEV_QTEST" is enabled.
+ */
+static int
+rte_qtest_virtio_pmd_uninit(const char *name)
+{
+	struct rte_eth_dev *eth_dev;
+	struct virtio_hw *hw;
+	int ret;
+
+	if (name == NULL)
+		return -EINVAL;
+
+	/* find the ethdev entry */
+	eth_dev = rte_eth_dev_allocated(name);
+	if (eth_dev == NULL)
+		return -ENODEV;
+
+	ret = eth_virtio_dev_uninit(eth_dev);
+	if (ret != 0)
+		return -EFAULT;
+
+	hw = eth_dev->data->dev_private;
+	qtest_vdev_uninit(hw->qsession);
+
+	ret = virtio_net_eth_dev_free(eth_dev);
+	if (ret != 0)
+		return -EFAULT;
+
+	return 0;
+}
+
+static struct rte_driver rte_qtest_virtio_driver = {
+	.name   = QTEST_DRV_NAME,
+	.type   = PMD_VDEV,
+	.init   = rte_qtest_virtio_pmd_init,
+	.uninit = rte_qtest_virtio_pmd_uninit,
+};
+
+PMD_REGISTER_DRIVER(rte_qtest_virtio_driver);
+#endif /* RTE_VIRTIO_VDEV_QTEST */
-- 
2.1.4