netdevsim: add SR-IOV functionality

dummy driver was extended with VF-related netdev APIs for testing
SR-IOV-related software.  netdevsim did not exist back then.
Implement SR-IOV functionality in netdevsim.  Notable difference
is that since netdevsim has no module parameters, we will actually
create a device with sriov_numvfs attribute for each netdev.
The zero MAC address is accepted as some HW use it to mean any
address is allowed.  Link state is also now validated.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

drivers/net/netdevsim/netdev.c

@@ -25,6 +25,125 @@
 
 #include "netdevsim.h"
 
+struct nsim_vf_config {
+	int link_state;
+	u16 min_tx_rate;
+	u16 max_tx_rate;
+	u16 vlan;
+	__be16 vlan_proto;
+	u16 qos;
+	u8 vf_mac[ETH_ALEN];
+	bool spoofchk_enabled;
+	bool trusted;
+	bool rss_query_enabled;
+};
+
+static u32 nsim_dev_id;
+
+static int nsim_num_vf(struct device *dev)
+{
+	struct netdevsim *ns = to_nsim(dev);
+
+	return ns->num_vfs;
+}
+
+static struct bus_type nsim_bus = {
+	.name		= DRV_NAME,
+	.dev_name	= DRV_NAME,
+	.num_vf		= nsim_num_vf,
+};
+
+static int nsim_vfs_enable(struct netdevsim *ns, unsigned int num_vfs)
+{
+	ns->vfconfigs = kcalloc(num_vfs, sizeof(struct nsim_vf_config),
+				GFP_KERNEL);
+	if (!ns->vfconfigs)
+		return -ENOMEM;
+	ns->num_vfs = num_vfs;
+
+	return 0;
+}
+
+static void nsim_vfs_disable(struct netdevsim *ns)
+{
+	kfree(ns->vfconfigs);
+	ns->vfconfigs = NULL;
+	ns->num_vfs = 0;
+}
+
+static ssize_t
+nsim_numvfs_store(struct device *dev, struct device_attribute *attr,
+		  const char *buf, size_t count)
+{
+	struct netdevsim *ns = to_nsim(dev);
+	unsigned int num_vfs;
+	int ret;
+
+	ret = kstrtouint(buf, 0, &num_vfs);
+	if (ret)
+		return ret;
+
+	rtnl_lock();
+	if (ns->num_vfs == num_vfs)
+		goto exit_good;
+	if (ns->num_vfs && num_vfs) {
+		ret = -EBUSY;
+		goto exit_unlock;
+	}
+
+	if (num_vfs) {
+		ret = nsim_vfs_enable(ns, num_vfs);
+		if (ret)
+			goto exit_unlock;
+	} else {
+		nsim_vfs_disable(ns);
+	}
+exit_good:
+	ret = count;
+exit_unlock:
+	rtnl_unlock();
+
+	return ret;
+}
+
+static ssize_t
+nsim_numvfs_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct netdevsim *ns = to_nsim(dev);
+
+	return sprintf(buf, "%u\n", ns->num_vfs);
+}
+
+static struct device_attribute nsim_numvfs_attr =
+	__ATTR(sriov_numvfs, 0664, nsim_numvfs_show, nsim_numvfs_store);
+
+static struct attribute *nsim_dev_attrs[] = {
+	&nsim_numvfs_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group nsim_dev_attr_group = {
+	.attrs = nsim_dev_attrs,
+};
+
+static const struct attribute_group *nsim_dev_attr_groups[] = {
+	&nsim_dev_attr_group,
+	NULL,
+};
+
+static void nsim_dev_release(struct device *dev)
+{
+	struct netdevsim *ns = to_nsim(dev);
+
+	nsim_vfs_disable(ns);
+	free_netdev(ns->netdev);
+}
+
+struct device_type nsim_dev_type = {
+	.groups = nsim_dev_attr_groups,
+	.release = nsim_dev_release,
+};
+
 static int nsim_init(struct net_device *dev)
 {
 	struct netdevsim *ns = netdev_priv(dev);
@@ -37,8 +156,19 @@ static int nsim_init(struct net_device *dev)
 	if (err)
 		goto err_debugfs_destroy;
 
+	ns->dev.id = nsim_dev_id++;
+	ns->dev.bus = &nsim_bus;
+	ns->dev.type = &nsim_dev_type;
+	err = device_register(&ns->dev);
+	if (err)
+		goto err_bpf_uninit;
+
+	SET_NETDEV_DEV(dev, &ns->dev);
+
 	return 0;
 
+err_bpf_uninit:
+	nsim_bpf_uninit(ns);
 err_debugfs_destroy:
 	debugfs_remove_recursive(ns->ddir);
 	return err;
@@ -52,6 +182,14 @@ static void nsim_uninit(struct net_device *dev)
 	nsim_bpf_uninit(ns);
 }
 
+static void nsim_free(struct net_device *dev)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	device_unregister(&ns->dev);
+	/* netdev and vf state will be freed out of device_release() */
+}
+
 static netdev_tx_t nsim_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct netdevsim *ns = netdev_priv(dev);
@@ -122,6 +260,123 @@ nsim_setup_tc_block(struct net_device *dev, struct tc_block_offload *f)
 	}
 }
 
+static int nsim_set_vf_mac(struct net_device *dev, int vf, u8 *mac)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	/* Only refuse multicast addresses, zero address can mean unset/any. */
+	if (vf >= ns->num_vfs || is_multicast_ether_addr(mac))
+		return -EINVAL;
+	memcpy(ns->vfconfigs[vf].vf_mac, mac, ETH_ALEN);
+
+	return 0;
+}
+
+static int nsim_set_vf_vlan(struct net_device *dev, int vf,
+			    u16 vlan, u8 qos, __be16 vlan_proto)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (vf >= ns->num_vfs || vlan > 4095 || qos > 7)
+		return -EINVAL;
+
+	ns->vfconfigs[vf].vlan = vlan;
+	ns->vfconfigs[vf].qos = qos;
+	ns->vfconfigs[vf].vlan_proto = vlan_proto;
+
+	return 0;
+}
+
+static int nsim_set_vf_rate(struct net_device *dev, int vf, int min, int max)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (vf >= ns->num_vfs)
+		return -EINVAL;
+
+	ns->vfconfigs[vf].min_tx_rate = min;
+	ns->vfconfigs[vf].max_tx_rate = max;
+
+	return 0;
+}
+
+static int nsim_set_vf_spoofchk(struct net_device *dev, int vf, bool val)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (vf >= ns->num_vfs)
+		return -EINVAL;
+	ns->vfconfigs[vf].spoofchk_enabled = val;
+
+	return 0;
+}
+
+static int nsim_set_vf_rss_query_en(struct net_device *dev, int vf, bool val)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (vf >= ns->num_vfs)
+		return -EINVAL;
+	ns->vfconfigs[vf].rss_query_enabled = val;
+
+	return 0;
+}
+
+static int nsim_set_vf_trust(struct net_device *dev, int vf, bool val)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (vf >= ns->num_vfs)
+		return -EINVAL;
+	ns->vfconfigs[vf].trusted = val;
+
+	return 0;
+}
+
+static int
+nsim_get_vf_config(struct net_device *dev, int vf, struct ifla_vf_info *ivi)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (vf >= ns->num_vfs)
+		return -EINVAL;
+
+	ivi->vf = vf;
+	ivi->linkstate = ns->vfconfigs[vf].link_state;
+	ivi->min_tx_rate = ns->vfconfigs[vf].min_tx_rate;
+	ivi->max_tx_rate = ns->vfconfigs[vf].max_tx_rate;
+	ivi->vlan = ns->vfconfigs[vf].vlan;
+	ivi->vlan_proto = ns->vfconfigs[vf].vlan_proto;
+	ivi->qos = ns->vfconfigs[vf].qos;
+	memcpy(&ivi->mac, ns->vfconfigs[vf].vf_mac, ETH_ALEN);
+	ivi->spoofchk = ns->vfconfigs[vf].spoofchk_enabled;
+	ivi->trusted = ns->vfconfigs[vf].trusted;
+	ivi->rss_query_en = ns->vfconfigs[vf].rss_query_enabled;
+
+	return 0;
+}
+
+static int nsim_set_vf_link_state(struct net_device *dev, int vf, int state)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (vf >= ns->num_vfs)
+		return -EINVAL;
+
+	switch (state) {
+	case IFLA_VF_LINK_STATE_AUTO:
+	case IFLA_VF_LINK_STATE_ENABLE:
+	case IFLA_VF_LINK_STATE_DISABLE:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ns->vfconfigs[vf].link_state = state;
+
+	return 0;
+}
+
 static int
 nsim_setup_tc(struct net_device *dev, enum tc_setup_type type, void *type_data)
 {
@@ -153,6 +408,14 @@ static const struct net_device_ops nsim_netdev_ops = {
 	.ndo_validate_addr	= eth_validate_addr,
 	.ndo_change_mtu		= nsim_change_mtu,
 	.ndo_get_stats64	= nsim_get_stats64,
+	.ndo_set_vf_mac		= nsim_set_vf_mac,
+	.ndo_set_vf_vlan	= nsim_set_vf_vlan,
+	.ndo_set_vf_rate	= nsim_set_vf_rate,
+	.ndo_set_vf_spoofchk	= nsim_set_vf_spoofchk,
+	.ndo_set_vf_trust	= nsim_set_vf_trust,
+	.ndo_get_vf_config	= nsim_get_vf_config,
+	.ndo_set_vf_link_state	= nsim_set_vf_link_state,
+	.ndo_set_vf_rss_query_en = nsim_set_vf_rss_query_en,
 	.ndo_setup_tc		= nsim_setup_tc,
 	.ndo_set_features	= nsim_set_features,
 	.ndo_bpf		= nsim_bpf,
@@ -164,7 +427,7 @@ static void nsim_setup(struct net_device *dev)
 	eth_hw_addr_random(dev);
 
 	dev->netdev_ops = &nsim_netdev_ops;
-	dev->needs_free_netdev = true;
+	dev->priv_destructor = nsim_free;
 
 	dev->tx_queue_len = 0;
 	dev->flags |= IFF_NOARP;
@@ -209,12 +472,18 @@ static int __init nsim_module_init(void)
 	if (IS_ERR(nsim_ddir))
 		return PTR_ERR(nsim_ddir);
 
-	err = rtnl_link_register(&nsim_link_ops);
+	err = bus_register(&nsim_bus);
 	if (err)
 		goto err_debugfs_destroy;
 
+	err = rtnl_link_register(&nsim_link_ops);
+	if (err)
+		goto err_unreg_bus;
+
 	return 0;
 
+err_unreg_bus:
+	bus_unregister(&nsim_bus);
 err_debugfs_destroy:
 	debugfs_remove_recursive(nsim_ddir);
 	return err;
@@ -223,6 +492,7 @@ static int __init nsim_module_init(void)
 static void __exit nsim_module_exit(void)
 {
 	rtnl_link_unregister(&nsim_link_ops);
+	bus_unregister(&nsim_bus);
 	debugfs_remove_recursive(nsim_ddir);
 }
 

drivers/net/netdevsim/netdevsim.h

@@ -13,6 +13,7 @@
  * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
  */
 
+#include <linux/device.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/netdevice.h>
@@ -26,6 +27,7 @@
 
 struct bpf_prog;
 struct dentry;
+struct nsim_vf_config;
 
 struct netdevsim {
 	struct net_device *netdev;
@@ -34,8 +36,13 @@ struct netdevsim {
 	u64 tx_bytes;
 	struct u64_stats_sync syncp;
 
+	struct device dev;
+
 	struct dentry *ddir;
 
+	unsigned int num_vfs;
+	struct nsim_vf_config *vfconfigs;
+
 	struct bpf_prog	*bpf_offloaded;
 	u32 bpf_offloaded_id;
 
@@ -64,3 +71,8 @@ int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf);
 int nsim_bpf_disable_tc(struct netdevsim *ns);
 int nsim_bpf_setup_tc_block_cb(enum tc_setup_type type,
 			       void *type_data, void *cb_priv);
+
+static inline struct netdevsim *to_nsim(struct device *ptr)
+{
+	return container_of(ptr, struct netdevsim, dev);
+}