vdpa: Enable user to set mac and mtu of vdpa device

$ vdpa dev add name bar mgmtdev vdpasim_net mac 00:11:22:33:44:55 mtu 9000

$ vdpa dev config show
bar: mac 00:11:22:33:44:55 link up link_announce false mtu 9000

$ vdpa dev config show -jp
{
    "config": {
        "bar": {
            "mac": "00:11:22:33:44:55",
            "link ": "up",
            "link_announce ": false,
            "mtu": 9000,
        }
    }
}
Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Eli Cohen <elic@nvidia.com>
Acked-by: Jason Wang <jasowang@redhat.com>

Link: https://lore.kernel.org/r/20211026175519.87795-5-parav@nvidia.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

drivers/vdpa/ifcvf/ifcvf_main.c

@@ -499,7 +499,8 @@ static u32 get_dev_type(struct pci_dev *pdev)
 	return dev_type;
 }
 
-static int ifcvf_vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name)
+static int ifcvf_vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
+			      const struct vdpa_dev_set_config *config)
 {
 	struct ifcvf_vdpa_mgmt_dev *ifcvf_mgmt_dev;
 	struct ifcvf_adapter *adapter;

drivers/vdpa/mlx5/net/mlx5_vnet.c

@@ -2482,7 +2482,8 @@ static int event_handler(struct notifier_block *nb, unsigned long event, void *p
 	return ret;
 }
 
-static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name)
+static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
+			     const struct vdpa_dev_set_config *add_config)
 {
 	struct mlx5_vdpa_mgmtdev *mgtdev = container_of(v_mdev, struct mlx5_vdpa_mgmtdev, mgtdev);
 	struct virtio_net_config *config;

drivers/vdpa/vdpa.c

@@ -14,7 +14,6 @@
 #include <uapi/linux/vdpa.h>
 #include <net/genetlink.h>
 #include <linux/mod_devicetable.h>
-#include <linux/virtio_net.h>
 #include <linux/virtio_ids.h>
 
 static LIST_HEAD(mdev_head);
@@ -480,9 +479,15 @@ vdpa_nl_cmd_mgmtdev_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb)
 	return msg->len;
 }
 
+#define VDPA_DEV_NET_ATTRS_MASK ((1 << VDPA_ATTR_DEV_NET_CFG_MACADDR) | \
+				 (1 << VDPA_ATTR_DEV_NET_CFG_MTU))
+
 static int vdpa_nl_cmd_dev_add_set_doit(struct sk_buff *skb, struct genl_info *info)
 {
+	struct vdpa_dev_set_config config = {};
+	struct nlattr **nl_attrs = info->attrs;
 	struct vdpa_mgmt_dev *mdev;
+	const u8 *macaddr;
 	const char *name;
 	int err = 0;
 
@@ -491,6 +496,26 @@ static int vdpa_nl_cmd_dev_add_set_doit(struct sk_buff *skb, struct genl_info *i
 
 	name = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);
 
+	if (nl_attrs[VDPA_ATTR_DEV_NET_CFG_MACADDR]) {
+		macaddr = nla_data(nl_attrs[VDPA_ATTR_DEV_NET_CFG_MACADDR]);
+		memcpy(config.net.mac, macaddr, sizeof(config.net.mac));
+		config.mask |= (1 << VDPA_ATTR_DEV_NET_CFG_MACADDR);
+	}
+	if (nl_attrs[VDPA_ATTR_DEV_NET_CFG_MTU]) {
+		config.net.mtu =
+			nla_get_u16(nl_attrs[VDPA_ATTR_DEV_NET_CFG_MTU]);
+		config.mask |= (1 << VDPA_ATTR_DEV_NET_CFG_MTU);
+	}
+
+	/* Skip checking capability if user didn't prefer to configure any
+	 * device networking attributes. It is likely that user might have used
+	 * a device specific method to configure such attributes or using device
+	 * default attributes.
+	 */
+	if ((config.mask & VDPA_DEV_NET_ATTRS_MASK) &&
+	    !netlink_capable(skb, CAP_NET_ADMIN))
+		return -EPERM;
+
 	mutex_lock(&vdpa_dev_mutex);
 	mdev = vdpa_mgmtdev_get_from_attr(info->attrs);
 	if (IS_ERR(mdev)) {
@@ -498,8 +523,14 @@ static int vdpa_nl_cmd_dev_add_set_doit(struct sk_buff *skb, struct genl_info *i
 		err = PTR_ERR(mdev);
 		goto err;
 	}
+	if ((config.mask & mdev->config_attr_mask) != config.mask) {
+		NL_SET_ERR_MSG_MOD(info->extack,
+				   "All provided attributes are not supported");
+		err = -EOPNOTSUPP;
+		goto err;
+	}
 
-	err = mdev->ops->dev_add(mdev, name);
+	err = mdev->ops->dev_add(mdev, name, &config);
 err:
 	mutex_unlock(&vdpa_dev_mutex);
 	return err;
@@ -835,6 +866,9 @@ static const struct nla_policy vdpa_nl_policy[VDPA_ATTR_MAX + 1] = {
 	[VDPA_ATTR_MGMTDEV_BUS_NAME] = { .type = NLA_NUL_STRING },
 	[VDPA_ATTR_MGMTDEV_DEV_NAME] = { .type = NLA_STRING },
 	[VDPA_ATTR_DEV_NAME] = { .type = NLA_STRING },
+	[VDPA_ATTR_DEV_NET_CFG_MACADDR] = NLA_POLICY_ETH_ADDR,
+	/* virtio spec 1.1 section 5.1.4.1 for valid MTU range */
+	[VDPA_ATTR_DEV_NET_CFG_MTU] = NLA_POLICY_MIN(NLA_U16, 68),
 };
 
 static const struct genl_ops vdpa_nl_ops[] = {

drivers/vdpa/vdpa_sim/vdpa_sim_blk.c

@@ -248,7 +248,8 @@ static struct device vdpasim_blk_mgmtdev = {
 	.release = vdpasim_blk_mgmtdev_release,
 };
 
-static int vdpasim_blk_dev_add(struct vdpa_mgmt_dev *mdev, const char *name)
+static int vdpasim_blk_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;

drivers/vdpa/vdpa_sim/vdpa_sim_net.c

@@ -126,7 +126,8 @@ static struct device vdpasim_net_mgmtdev = {
 	.release = vdpasim_net_mgmtdev_release,
 };
 
-static int vdpasim_net_dev_add(struct vdpa_mgmt_dev *mdev, const char *name)
+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;

drivers/vdpa/vdpa_user/vduse_dev.c

@@ -1503,7 +1503,8 @@ static int vduse_dev_init_vdpa(struct vduse_dev *dev, const char *name)
 	return 0;
 }
 
-static int vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name)
+static int vdpa_dev_add(struct vdpa_mgmt_dev *mdev, const char *name,
+			const struct vdpa_dev_set_config *config)
 {
 	struct vduse_dev *dev;
 	int ret;

include/linux/vdpa.h

@@ -6,6 +6,8 @@
 #include <linux/device.h>
 #include <linux/interrupt.h>
 #include <linux/vhost_iotlb.h>
+#include <linux/virtio_net.h>
+#include <linux/if_ether.h>
 
 /**
  * struct vdpa_calllback - vDPA callback definition.
@@ -93,6 +95,14 @@ struct vdpa_iova_range {
 	u64 last;
 };
 
+struct vdpa_dev_set_config {
+	struct {
+		u8 mac[ETH_ALEN];
+		u16 mtu;
+	} net;
+	u64 mask;
+};
+
 /**
  * Corresponding file area for device memory mapping
  * @file: vma->vm_file for the mapping
@@ -397,6 +407,7 @@ void vdpa_set_config(struct vdpa_device *dev, unsigned int offset,
  * @dev_add: Add a vdpa device using alloc and register
  *	     @mdev: parent device to use for device addition
  *	     @name: name of the new vdpa device
+ *	     @config: config attributes to apply to the device under creation
  *	     Driver need to add a new device using _vdpa_register_device()
  *	     after fully initializing the vdpa device. Driver must return 0
  *	     on success or appropriate error code.
@@ -407,7 +418,8 @@ void vdpa_set_config(struct vdpa_device *dev, unsigned int offset,
  *	     _vdpa_unregister_device().
  */
 struct vdpa_mgmtdev_ops {
-	int (*dev_add)(struct vdpa_mgmt_dev *mdev, const char *name);
+	int (*dev_add)(struct vdpa_mgmt_dev *mdev, const char *name,
+		       const struct vdpa_dev_set_config *config);
 	void (*dev_del)(struct vdpa_mgmt_dev *mdev, struct vdpa_device *dev);
 };
 
@@ -416,12 +428,15 @@ struct vdpa_mgmtdev_ops {
  * @device: Management parent device
  * @ops: operations supported by management device
  * @id_table: Pointer to device id table of supported ids
+ * @config_attr_mask: bit mask of attributes of type enum vdpa_attr that
+ *		      management device support during dev_add callback
  * @list: list entry
  */
 struct vdpa_mgmt_dev {
 	struct device *device;
 	const struct vdpa_mgmtdev_ops *ops;
 	const struct virtio_device_id *id_table;
+	u64 config_attr_mask;
 	struct list_head list;
 };