enable virtio_net to return bus_info in ethtool -i consistent with emulated NICs

Add a new .bus_name to virtio_config_ops then modify virtio_net to
call through to it in an ethtool .get_drvinfo routine to report
bus_info in ethtool -i output which is consistent with other
emulated NICs and the output of lspci.
Signed-off-by: Rick Jones <rick.jones2@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/lguest/lguest_device.c

@@ -381,6 +381,11 @@ static int lg_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 	return PTR_ERR(vqs[i]);
 }
 
+static const char *lg_bus_name(struct virtio_device *vdev)
+{
+	return "";
+}
+
 /* The ops structure which hooks everything together. */
 static struct virtio_config_ops lguest_config_ops = {
 	.get_features = lg_get_features,
@@ -392,6 +397,7 @@ static struct virtio_config_ops lguest_config_ops = {
 	.reset = lg_reset,
 	.find_vqs = lg_find_vqs,
 	.del_vqs = lg_del_vqs,
+	.bus_name = lg_bus_name,
 };
 
 /*

drivers/net/virtio_net.c

@@ -39,6 +39,7 @@ module_param(gso, bool, 0444);
 #define GOOD_COPY_LEN	128
 
 #define VIRTNET_SEND_COMMAND_SG_MAX    2
+#define VIRTNET_DRIVER_VERSION "1.0.0"
 
 struct virtnet_stats {
 	struct u64_stats_sync syncp;
@@ -889,7 +890,21 @@ static void virtnet_get_ringparam(struct net_device *dev,
 
 }
 
+
+static void virtnet_get_drvinfo(struct net_device *dev,
+				struct ethtool_drvinfo *info)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+	struct virtio_device *vdev = vi->vdev;
+
+	strlcpy(info->driver, KBUILD_MODNAME, sizeof(info->driver));
+	strlcpy(info->version, VIRTNET_DRIVER_VERSION, sizeof(info->version));
+	strlcpy(info->bus_info, virtio_bus_name(vdev), sizeof(info->bus_info));
+
+}
+
 static const struct ethtool_ops virtnet_ethtool_ops = {
+	.get_drvinfo = virtnet_get_drvinfo,
 	.get_link = ethtool_op_get_link,
 	.get_ringparam = virtnet_get_ringparam,
 };

drivers/s390/kvm/kvm_virtio.c

@@ -263,6 +263,11 @@ static int kvm_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 	return PTR_ERR(vqs[i]);
 }
 
+static const char *kvm_bus_name(struct virtio_device *vdev)
+{
+	return "";
+}
+
 /*
  * The config ops structure as defined by virtio config
  */
@@ -276,6 +281,7 @@ static struct virtio_config_ops kvm_vq_configspace_ops = {
 	.reset = kvm_reset,
 	.find_vqs = kvm_find_vqs,
 	.del_vqs = kvm_del_vqs,
+	.bus_name = kvm_bus_name,
 };
 
 /*

drivers/virtio/virtio_mmio.c

@@ -361,7 +361,12 @@ static int vm_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 	return 0;
 }
 
+static const char *vm_bus_name(struct virtio_device *vdev)
+{
+	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 
+	return vm_dev->pdev->name;
+}
 
 static struct virtio_config_ops virtio_mmio_config_ops = {
 	.get		= vm_get,
@@ -373,6 +378,7 @@ static struct virtio_config_ops virtio_mmio_config_ops = {
 	.del_vqs	= vm_del_vqs,
 	.get_features	= vm_get_features,
 	.finalize_features = vm_finalize_features,
+	.bus_name	= vm_bus_name,
 };
 
 

drivers/virtio/virtio_pci.c

@@ -580,6 +580,13 @@ static int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 				  false, false);
 }
 
+static const char *vp_bus_name(struct virtio_device *vdev)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+
+	return pci_name(vp_dev->pci_dev);
+}
+
 static struct virtio_config_ops virtio_pci_config_ops = {
 	.get		= vp_get,
 	.set		= vp_set,
@@ -590,6 +597,7 @@ static struct virtio_config_ops virtio_pci_config_ops = {
 	.del_vqs	= vp_del_vqs,
 	.get_features	= vp_get_features,
 	.finalize_features = vp_finalize_features,
+	.bus_name	= vp_bus_name,
 };
 
 static void virtio_pci_release_dev(struct device *_d)

include/linux/virtio_config.h

@@ -100,6 +100,10 @@
  *	vdev: the virtio_device
  *	This gives the final feature bits for the device: it can change
  *	the dev->feature bits if it wants.
+ * @bus_name: return the bus name associated with the device
+ *	vdev: the virtio_device
+ *      This returns a pointer to the bus name a la pci_name from which
+ *      the caller can then copy.
  */
 typedef void vq_callback_t(struct virtqueue *);
 struct virtio_config_ops {
@@ -117,6 +121,7 @@ struct virtio_config_ops {
 	void (*del_vqs)(struct virtio_device *);
 	u32 (*get_features)(struct virtio_device *vdev);
 	void (*finalize_features)(struct virtio_device *vdev);
+	const char *(*bus_name)(struct virtio_device *vdev);
 };
 
 /* If driver didn't advertise the feature, it will never appear. */
@@ -182,5 +187,14 @@ struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev,
 		return ERR_PTR(err);
 	return vq;
 }
+
+static inline
+const char *virtio_bus_name(struct virtio_device *vdev)
+{
+	if (!vdev->config->bus_name)
+		return "virtio";
+	return vdev->config->bus_name(vdev);
+}
+
 #endif /* __KERNEL__ */
 #endif /* _LINUX_VIRTIO_CONFIG_H */