1 files changed, 338 insertions, 0 deletions
diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim_net.c b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
new file mode 100644
index 000000000..584b975a9
--- /dev/null
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim_net.c
@@ -0,0 +1,338 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * VDPA simulator for networking device.
+ *
+ * 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/sched.h>
+#include <linux/etherdevice.h>
+#include <linux/vringh.h>
+#include <linux/vdpa.h>
+#include <uapi/linux/virtio_net.h>
+#include <uapi/linux/vdpa.h>
+
+#include "vdpa_sim.h"
+
+#define DRV_VERSION  "0.1"
+#define DRV_AUTHOR   "Jason Wang <jasowang@redhat.com>"
+#define DRV_DESC     "vDPA Device Simulator for networking device"
+#define DRV_LICENSE  "GPL v2"
+
+#define VDPASIM_NET_FEATURES	(VDPASIM_FEATURES | \
+				 (1ULL << VIRTIO_NET_F_MAC) | \
+				 (1ULL << VIRTIO_NET_F_MTU) | \
+				 (1ULL << VIRTIO_NET_F_CTRL_VQ) | \
+				 (1ULL << VIRTIO_NET_F_CTRL_MAC_ADDR))
+
+/* 3 virtqueues, 2 address spaces, 2 virtqueue groups */
+#define VDPASIM_NET_VQ_NUM	3
+#define VDPASIM_NET_AS_NUM	2
+#define VDPASIM_NET_GROUP_NUM	2
+
+static void vdpasim_net_complete(struct vdpasim_virtqueue *vq, size_t len)
+{
+	/* Make sure data is wrote before advancing index */
+	smp_wmb();
+
+	vringh_complete_iotlb(&vq->vring, vq->head, len);
+
+	/* Make sure used is visible before rasing the interrupt. */
+	smp_wmb();
+
+	local_bh_disable();
+	if (vringh_need_notify_iotlb(&vq->vring) > 0)
+		vringh_notify(&vq->vring);
+	local_bh_enable();
+}
+
+static bool receive_filter(struct vdpasim *vdpasim, size_t len)
+{
+	bool modern = vdpasim->features & (1ULL << VIRTIO_F_VERSION_1);
+	size_t hdr_len = modern ? sizeof(struct virtio_net_hdr_v1) :
+				  sizeof(struct virtio_net_hdr);
+	struct virtio_net_config *vio_config = vdpasim->config;
+
+	if (len < ETH_ALEN + hdr_len)
+		return false;
+
+	if (is_broadcast_ether_addr(vdpasim->buffer + hdr_len) ||
+	    is_multicast_ether_addr(vdpasim->buffer + hdr_len))
+		return true;
+	if (!strncmp(vdpasim->buffer + hdr_len, vio_config->mac, ETH_ALEN))
+		return true;
+
+	return false;
+}
+
+static virtio_net_ctrl_ack vdpasim_handle_ctrl_mac(struct vdpasim *vdpasim,
+						   u8 cmd)
+{
+	struct virtio_net_config *vio_config = vdpasim->config;
+	struct vdpasim_virtqueue *cvq = &vdpasim->vqs[2];
+	virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
+	size_t read;
+
+	switch (cmd) {
+	case VIRTIO_NET_CTRL_MAC_ADDR_SET:
+		read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->in_iov,
+					     vio_config->mac, ETH_ALEN);
+		if (read == ETH_ALEN)
+			status = VIRTIO_NET_OK;
+		break;
+	default:
+		break;
+	}
+
+	return status;
+}
+
+static void vdpasim_handle_cvq(struct vdpasim *vdpasim)
+{
+	struct vdpasim_virtqueue *cvq = &vdpasim->vqs[2];
+	virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
+	struct virtio_net_ctrl_hdr ctrl;
+	size_t read, write;
+	int err;
+
+	if (!(vdpasim->features & (1ULL << VIRTIO_NET_F_CTRL_VQ)))
+		return;
+
+	if (!cvq->ready)
+		return;
+
+	while (true) {
+		err = vringh_getdesc_iotlb(&cvq->vring, &cvq->in_iov,
+					   &cvq->out_iov,
+					   &cvq->head, GFP_ATOMIC);
+		if (err <= 0)
+			break;
+
+		read = vringh_iov_pull_iotlb(&cvq->vring, &cvq->in_iov, &ctrl,
+					     sizeof(ctrl));
+		if (read != sizeof(ctrl))
+			break;
+
+		switch (ctrl.class) {
+		case VIRTIO_NET_CTRL_MAC:
+			status = vdpasim_handle_ctrl_mac(vdpasim, ctrl.cmd);
+			break;
+		default:
+			break;
+		}
+
+		/* Make sure data is wrote before advancing index */
+		smp_wmb();
+
+		write = vringh_iov_push_iotlb(&cvq->vring, &cvq->out_iov,
+					      &status, sizeof(status));
+		vringh_complete_iotlb(&cvq->vring, cvq->head, write);
+		vringh_kiov_cleanup(&cvq->in_iov);
+		vringh_kiov_cleanup(&cvq->out_iov);
+
+		/* Make sure used is visible before rasing the interrupt. */
+		smp_wmb();
+
+		local_bh_disable();
+		if (cvq->cb)
+			cvq->cb(cvq->private);
+		local_bh_enable();
+	}
+}
+
+static void vdpasim_net_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];
+	ssize_t read, write;
+	int pkts = 0;
+	int err;
+
+	spin_lock(&vdpasim->lock);
+
+	if (!vdpasim->running)
+		goto out;
+
+	if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
+		goto out;
+
+	vdpasim_handle_cvq(vdpasim);
+
+	if (!txq->ready || !rxq->ready)
+		goto out;
+
+	while (true) {
+		err = vringh_getdesc_iotlb(&txq->vring, &txq->out_iov, NULL,
+					   &txq->head, GFP_ATOMIC);
+		if (err <= 0)
+			break;
+
+		read = vringh_iov_pull_iotlb(&txq->vring, &txq->out_iov,
+					     vdpasim->buffer,
+					     PAGE_SIZE);
+
+		if (!receive_filter(vdpasim, read)) {
+			vdpasim_net_complete(txq, 0);
+			continue;
+		}
+
+		err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->in_iov,
+					   &rxq->head, GFP_ATOMIC);
+		if (err <= 0) {
+			vdpasim_net_complete(txq, 0);
+			break;
+		}
+
+		write = vringh_iov_push_iotlb(&rxq->vring, &rxq->in_iov,
+					      vdpasim->buffer, read);
+		if (write <= 0)
+			break;
+
+		vdpasim_net_complete(txq, 0);
+		vdpasim_net_complete(rxq, write);
+
+		if (++pkts > 4) {
+			schedule_work(&vdpasim->work);
+			goto out;
+		}
+	}
+
+out:
+	spin_unlock(&vdpasim->lock);
+}
+
+static void vdpasim_net_get_config(struct vdpasim *vdpasim, void *config)
+{
+	struct virtio_net_config *net_config = config;
+
+	net_config->status = cpu_to_vdpasim16(vdpasim, VIRTIO_NET_S_LINK_UP);
+}
+
+static void vdpasim_net_setup_config(struct vdpasim *vdpasim,
+				     const struct vdpa_dev_set_config *config)
+{
+	struct virtio_net_config *vio_config = vdpasim->config;
+
+	if (config->mask & (1 << VDPA_ATTR_DEV_NET_CFG_MACADDR))
+		memcpy(vio_config->mac, config->net.mac, ETH_ALEN);
+	if (config->mask & (1 << VDPA_ATTR_DEV_NET_CFG_MTU))
+		vio_config->mtu = cpu_to_vdpasim16(vdpasim, config->net.mtu);
+	else
+		/* Setup default MTU to be 1500 */
+		vio_config->mtu = cpu_to_vdpasim16(vdpasim, 1500);
+}
+
+static void vdpasim_net_mgmtdev_release(struct device *dev)
+{
+}
+
+static struct device vdpasim_net_mgmtdev = {
+	.init_name = "vdpasim_net",
+	.release = vdpasim_net_mgmtdev_release,
+};
+
+static int vdpasim_net_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
+			       const struct vdpa_dev_set_config *config)
+{
+	struct vdpasim_dev_attr dev_attr = {};
+	struct vdpasim *simdev;
+	int ret;
+
+	dev_attr.mgmt_dev = mdev;
+	dev_attr.name = name;
+	dev_attr.id = VIRTIO_ID_NET;
+	dev_attr.supported_features = VDPASIM_NET_FEATURES;
+	dev_attr.nvqs = VDPASIM_NET_VQ_NUM;
+	dev_attr.ngroups = VDPASIM_NET_GROUP_NUM;
+	dev_attr.nas = VDPASIM_NET_AS_NUM;
+	dev_attr.config_size = sizeof(struct virtio_net_config);
+	dev_attr.get_config = vdpasim_net_get_config;
+	dev_attr.work_fn = vdpasim_net_work;
+	dev_attr.buffer_size = PAGE_SIZE;
+
+	simdev = vdpasim_create(&dev_attr, config);
+	if (IS_ERR(simdev))
+		return PTR_ERR(simdev);
+
+	vdpasim_net_setup_config(simdev, config);
+
+	ret = _vdpa_register_device(&simdev->vdpa, VDPASIM_NET_VQ_NUM);
+	if (ret)
+		goto reg_err;
+
+	return 0;
+
+reg_err:
+	put_device(&simdev->vdpa.dev);
+	return ret;
+}
+
+static void vdpasim_net_dev_del(struct vdpa_mgmt_dev *mdev,
+				struct vdpa_device *dev)
+{
+	struct vdpasim *simdev = container_of(dev, struct vdpasim, vdpa);
+
+	_vdpa_unregister_device(&simdev->vdpa);
+}
+
+static const struct vdpa_mgmtdev_ops vdpasim_net_mgmtdev_ops = {
+	.dev_add = vdpasim_net_dev_add,
+	.dev_del = vdpasim_net_dev_del
+};
+
+static struct virtio_device_id id_table[] = {
+	{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
+	{ 0 },
+};
+
+static struct vdpa_mgmt_dev mgmt_dev = {
+	.device = &vdpasim_net_mgmtdev,
+	.id_table = id_table,
+	.ops = &vdpasim_net_mgmtdev_ops,
+	.config_attr_mask = (1 << VDPA_ATTR_DEV_NET_CFG_MACADDR |
+			     1 << VDPA_ATTR_DEV_NET_CFG_MTU |
+		             1 << VDPA_ATTR_DEV_FEATURES),
+	.max_supported_vqs = VDPASIM_NET_VQ_NUM,
+	.supported_features = VDPASIM_NET_FEATURES,
+};
+
+static int __init vdpasim_net_init(void)
+{
+	int ret;
+
+	ret = device_register(&vdpasim_net_mgmtdev);
+	if (ret) {
+		put_device(&vdpasim_net_mgmtdev);
+		return ret;
+	}
+
+	ret = vdpa_mgmtdev_register(&mgmt_dev);
+	if (ret)
+		goto parent_err;
+	return 0;
+
+parent_err:
+	device_unregister(&vdpasim_net_mgmtdev);
+	return ret;
+}
+
+static void __exit vdpasim_net_exit(void)
+{
+	vdpa_mgmtdev_unregister(&mgmt_dev);
+	device_unregister(&vdpasim_net_mgmtdev);
+}
+
+module_init(vdpasim_net_init);
+module_exit(vdpasim_net_exit);
+
+MODULE_VERSION(DRV_VERSION);
+MODULE_LICENSE(DRV_LICENSE);
+MODULE_AUTHOR(DRV_AUTHOR);
+MODULE_DESCRIPTION(DRV_DESC);