[dpdk-dev] [PATCH v8 5/6] virtio-user: add new virtual pci driver for virtio

[Jianfeng Tan <jianfeng.tan@intel.com>]

This patch implements another new instance of struct virtio_pci_ops to
drive the virtio-user virtual device. Instead of rd/wr ioport or PCI
configuration space, this virtual pci driver will rd/wr the virtual
device struct virtio_user_hw, and when necessary, invokes APIs provided
by device emulation later to start/stop the device.

  ----------------------
  | ------------------ |
  | | virtio driver  | |----> (virtio_user_ethdev.c)
  | ------------------ |
  |         |          |
  | ------------------ | ------>  virtio-user PMD
  | | device emulate | |
  | |                | |
  | | vhost adapter  | |
  | ------------------ |
  ----------------------
            |
            |
            |
   ------------------
   | vhost backend  |
   ------------------

Signed-off-by: Huawei Xie <huawei.xie@intel.com>
Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
---
 drivers/net/virtio/Makefile             |   1 +
 drivers/net/virtio/virtio_pci.h         |   1 +
 drivers/net/virtio/virtio_user_ethdev.c | 218 ++++++++++++++++++++++++++++++++
 3 files changed, 220 insertions(+)
 create mode 100644 drivers/net/virtio/virtio_user_ethdev.c

diff --git a/drivers/net/virtio/Makefile b/drivers/net/virtio/Makefile
index d37b83d..43de46c 100644
--- a/drivers/net/virtio/Makefile
+++ b/drivers/net/virtio/Makefile
@@ -58,6 +58,7 @@ endif
 ifeq ($(CONFIG_RTE_VIRTIO_USER),y)
 SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_user/vhost_user.c
 SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_user/virtio_user_dev.c
+SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_user_ethdev.c
 endif
 
 # this lib depends upon:
diff --git a/drivers/net/virtio/virtio_pci.h b/drivers/net/virtio/virtio_pci.h
index 6c7f8d7..dd7693f 100644
--- a/drivers/net/virtio/virtio_pci.h
+++ b/drivers/net/virtio/virtio_pci.h
@@ -261,6 +261,7 @@ struct virtio_hw {
 	struct virtio_pci_common_cfg *common_cfg;
 	struct virtio_net_config *dev_cfg;
 	const struct virtio_pci_ops *vtpci_ops;
+	void	    *virtio_user_dev;
 };
 
 /*
diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
new file mode 100644
index 0000000..7814514
--- /dev/null
+++ b/drivers/net/virtio/virtio_user_ethdev.c
@@ -0,0 +1,218 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2016 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdint.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "virtio_logs.h"
+#include "virtio_pci.h"
+#include "virtqueue.h"
+#include "virtio_user/virtio_user_dev.h"
+
+#define virtio_user_get_dev(hw) \
+	((struct virtio_user_dev *)(hw)->virtio_user_dev);
+
+static void
+virtio_user_read_dev_config(struct virtio_hw *hw, size_t offset,
+		     void *dst, int length)
+{
+	int i;
+	struct virtio_user_dev *dev = virtio_user_get_dev(hw);
+
+	if (offset == offsetof(struct virtio_net_config, mac) &&
+	    length == ETHER_ADDR_LEN) {
+		for (i = 0; i < ETHER_ADDR_LEN; ++i)
+			((uint8_t *)dst)[i] = dev->mac_addr[i];
+		return;
+	}
+
+	if (offset == offsetof(struct virtio_net_config, status))
+		*(uint16_t *)dst = dev->status;
+
+	if (offset == offsetof(struct virtio_net_config, max_virtqueue_pairs))
+		*(uint16_t *)dst = dev->max_queue_pairs;
+}
+
+static void
+virtio_user_write_dev_config(struct virtio_hw *hw, size_t offset,
+		      const void *src, int length)
+{
+	int i;
+	struct virtio_user_dev *dev = virtio_user_get_dev(hw);
+
+	if ((offset == offsetof(struct virtio_net_config, mac)) &&
+	    (length == ETHER_ADDR_LEN))
+		for (i = 0; i < ETHER_ADDR_LEN; ++i)
+			dev->mac_addr[i] = ((const uint8_t *)src)[i];
+	else
+		PMD_DRV_LOG(ERR, "not supported offset=%" PRIu64 ", len=%d\n",
+			    offset, length);
+}
+
+static void
+virtio_user_set_status(struct virtio_hw *hw, uint8_t status)
+{
+	struct virtio_user_dev *dev = virtio_user_get_dev(hw);
+
+	if (status & VIRTIO_CONFIG_STATUS_DRIVER_OK)
+		virtio_user_start_device(dev);
+	dev->status = status;
+}
+
+static void
+virtio_user_reset(struct virtio_hw *hw)
+{
+	struct virtio_user_dev *dev = virtio_user_get_dev(hw);
+
+	virtio_user_stop_device(dev);
+}
+
+static uint8_t
+virtio_user_get_status(struct virtio_hw *hw)
+{
+	struct virtio_user_dev *dev = virtio_user_get_dev(hw);
+
+	return dev->status;
+}
+
+static uint64_t
+virtio_user_get_features(struct virtio_hw *hw)
+{
+	struct virtio_user_dev *dev = virtio_user_get_dev(hw);
+
+	return dev->features;
+}
+
+static void
+virtio_user_set_features(struct virtio_hw *hw, uint64_t features)
+{
+	struct virtio_user_dev *dev = virtio_user_get_dev(hw);
+
+	dev->features = features;
+}
+
+static uint8_t
+virtio_user_get_isr(struct virtio_hw *hw __rte_unused)
+{
+	/* When config interrupt happens, driver calls this function to query
+	 * what kinds of change happen. Interrupt mode not supported for now.
+	 */
+	return 0;
+}
+
+static uint16_t
+virtio_user_set_config_irq(struct virtio_hw *hw __rte_unused,
+		    uint16_t vec __rte_unused)
+{
+	return VIRTIO_MSI_NO_VECTOR;
+}
+
+/* This function is to get the queue size, aka, number of descs, of a specified
+ * queue. Different with the VHOST_USER_GET_QUEUE_NUM, which is used to get the
+ * max supported queues.
+ */
+static uint16_t
+virtio_user_get_queue_num(struct virtio_hw *hw, uint16_t queue_id __rte_unused)
+{
+	struct virtio_user_dev *dev = virtio_user_get_dev(hw);
+
+	/* Currently, each queue has same queue size */
+	return dev->queue_size;
+}
+
+static int
+virtio_user_setup_queue(struct virtio_hw *hw, struct virtqueue *vq)
+{
+	struct virtio_user_dev *dev = virtio_user_get_dev(hw);
+	uint16_t queue_idx = vq->vq_queue_index;
+	uint64_t desc_addr, avail_addr, used_addr;
+
+	desc_addr = (uintptr_t)vq->vq_ring_virt_mem;
+	avail_addr = desc_addr + vq->vq_nentries * sizeof(struct vring_desc);
+	used_addr = RTE_ALIGN_CEIL(avail_addr + offsetof(struct vring_avail,
+							 ring[vq->vq_nentries]),
+				   VIRTIO_PCI_VRING_ALIGN);
+
+	dev->vrings[queue_idx].num = vq->vq_nentries;
+	dev->vrings[queue_idx].desc = (void *)(uintptr_t)desc_addr;
+	dev->vrings[queue_idx].avail = (void *)(uintptr_t)avail_addr;
+	dev->vrings[queue_idx].used = (void *)(uintptr_t)used_addr;
+
+	return 0;
+}
+
+static void
+virtio_user_del_queue(struct virtio_hw *hw, struct virtqueue *vq)
+{
+	/* For legacy devices, write 0 to VIRTIO_PCI_QUEUE_PFN port, QEMU
+	 * correspondingly stops the ioeventfds, and reset the status of
+	 * the device.
+	 * For modern devices, set queue desc, avail, used in PCI bar to 0,
+	 * not see any more behavior in QEMU.
+	 *
+	 * Here we just care about what information to deliver to vhost-user
+	 * or vhost-kernel. So we just close ioeventfd for now.
+	 */
+	struct virtio_user_dev *dev = virtio_user_get_dev(hw);
+
+	close(dev->callfds[vq->vq_queue_index]);
+	close(dev->kickfds[vq->vq_queue_index]);
+}
+
+static void
+virtio_user_notify_queue(struct virtio_hw *hw, struct virtqueue *vq)
+{
+	uint64_t buf = 1;
+	struct virtio_user_dev *dev = virtio_user_get_dev(hw);
+
+	if (write(dev->kickfds[vq->vq_queue_index], &buf, sizeof(buf)) < 0)
+		PMD_DRV_LOG(ERR, "failed to kick backend: %s\n",
+			    strerror(errno));
+}
+
+static const struct virtio_pci_ops virtio_user_ops = {
+	.read_dev_cfg	= virtio_user_read_dev_config,
+	.write_dev_cfg	= virtio_user_write_dev_config,
+	.reset		= virtio_user_reset,
+	.get_status	= virtio_user_get_status,
+	.set_status	= virtio_user_set_status,
+	.get_features	= virtio_user_get_features,
+	.set_features	= virtio_user_set_features,
+	.get_isr	= virtio_user_get_isr,
+	.set_config_irq	= virtio_user_set_config_irq,
+	.get_queue_num	= virtio_user_get_queue_num,
+	.setup_queue	= virtio_user_setup_queue,
+	.del_queue	= virtio_user_del_queue,
+	.notify_queue	= virtio_user_notify_queue,
+};
-- 
2.1.4