[PATCH 2/2] vdpa: Add support to update speed/duplex in vDPA/mlx5_vnet

[Carlos Bilbao <carlos.bilbao.osdev@gmail.com>]

From: Carlos Bilbao <cbilbao@digitalocean.com>

Include support to update the vDPA configuration fields of speed and
duplex (as needed by VHOST_VDPA_SET_CONFIG). This includes function
mlx5_vdpa_set_config() as well as changes in vdpa.c to fill the initial
values to UNKNOWN. Also add a warning message for when
mlx5_vdpa_get_config() receives offset and length out of bounds.

Signed-off-by: Carlos Bilbao <cbilbao@digitalocean.com>
---
 drivers/vdpa/mlx5/net/mlx5_vnet.c | 34 ++++++++++++++++++++++++++++++-
 drivers/vdpa/vdpa.c               | 27 ++++++++++++++++++++++++
 include/uapi/linux/vdpa.h         |  2 ++
 3 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index c47009a8b472..a44bb2072eec 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -3221,12 +3221,44 @@ static void mlx5_vdpa_get_config(struct vdpa_device *vdev, unsigned int offset,
 
 	if (offset + len <= sizeof(struct virtio_net_config))
 		memcpy(buf, (u8 *)&ndev->config + offset, len);
+	else
+		mlx5_vdpa_warn(mvdev, "Offset and length out of bounds\n");
 }
 
 static void mlx5_vdpa_set_config(struct vdpa_device *vdev, unsigned int offset, const void *buf,
 				 unsigned int len)
 {
-	/* not supported */
+	struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);
+	struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev);
+
+	if (offset + len > sizeof(struct virtio_net_config)) {
+		mlx5_vdpa_warn(mvdev, "Offset and length out of bounds\n");
+		return;
+	}
+
+	/*
+	 * Note that this will update the speed/duplex configuration fields
+	 * but the hardware support to actually perform this change does
+	 * not exist yet.
+	 */
+	switch (offset) {
+	case offsetof(struct virtio_net_config, speed):
+		if (len == sizeof(((struct virtio_net_config *) 0)->speed))
+			memcpy(&ndev->config.speed, buf, len);
+		else
+			mlx5_vdpa_warn(mvdev, "Invalid length for speed.\n");
+		break;
+
+	case offsetof(struct virtio_net_config, duplex):
+		if (len == sizeof(((struct virtio_net_config *)0)->duplex))
+			memcpy(&ndev->config.duplex, buf, len);
+		else
+			mlx5_vdpa_warn(mvdev, "Invalid length for duplex.\n");
+		break;
+
+	default:
+		mlx5_vdpa_warn(mvdev, "Configuration field not supported.\n");
+	}
 }
 
 static u32 mlx5_vdpa_get_generation(struct vdpa_device *vdev)
diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
index 4dbd2e55a288..b920e4405f6d 100644
--- a/drivers/vdpa/vdpa.c
+++ b/drivers/vdpa/vdpa.c
@@ -15,6 +15,7 @@
 #include <net/genetlink.h>
 #include <linux/mod_devicetable.h>
 #include <linux/virtio_ids.h>
+#include <uapi/linux/ethtool.h>
 
 static LIST_HEAD(mdev_head);
 /* A global mutex that protects vdpa management device and device level operations. */
@@ -919,6 +920,22 @@ static int vdpa_dev_net_status_config_fill(struct sk_buff *msg, u64 features,
 	return nla_put_u16(msg, VDPA_ATTR_DEV_NET_STATUS, val_u16);
 }
 
+static int vdpa_dev_net_speed_config_fill(struct sk_buff *msg, u64 features,
+					struct virtio_net_config *config)
+{
+	__le32 speed = cpu_to_le32(SPEED_UNKNOWN);
+
+	return nla_put(msg, VDPA_ATTR_DEV_NET_CFG_SPEED, sizeof(speed), &speed);
+}
+
+static int vdpa_dev_net_duplex_config_fill(struct sk_buff *msg, u64 features,
+					struct virtio_net_config *config)
+{
+	u8 duplex = DUPLEX_UNKNOWN;
+
+	return nla_put(msg, VDPA_ATTR_DEV_NET_CFG_DUPLEX, sizeof(duplex), &duplex);
+}
+
 static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *msg)
 {
 	struct virtio_net_config config = {};
@@ -940,6 +957,16 @@ static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *ms
 
 	if (vdpa_dev_net_status_config_fill(msg, features_device, &config))
 		return -EMSGSIZE;
+	/*
+	 * mlx5_vdpa vDPA devicess currently do not support the
+	 * VIRTIO_NET_F_SPEED_DUPLEX feature, which reports speed and
+	 * duplex; hence these are set to UNKNOWN for now.
+	 */
+	if (vdpa_dev_net_speed_config_fill(msg, features_device, &config))
+		return -EMSGSIZE;
+
+	if (vdpa_dev_net_duplex_config_fill(msg, features_device, &config))
+		return -EMSGSIZE;
 
 	return vdpa_dev_net_mq_config_fill(msg, features_device, &config);
 }
diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
index 842bf1201ac4..1c64ee0dd7b1 100644
--- a/include/uapi/linux/vdpa.h
+++ b/include/uapi/linux/vdpa.h
@@ -43,6 +43,8 @@ enum vdpa_attr {
 	VDPA_ATTR_DEV_NET_STATUS,		/* u8 */
 	VDPA_ATTR_DEV_NET_CFG_MAX_VQP,		/* u16 */
 	VDPA_ATTR_DEV_NET_CFG_MTU,		/* u16 */
+	VDPA_ATTR_DEV_NET_CFG_SPEED,		/* u32 */
+	VDPA_ATTR_DEV_NET_CFG_DUPLEX,		/* u8 */
 
 	VDPA_ATTR_DEV_NEGOTIATED_FEATURES,	/* u64 */
 	VDPA_ATTR_DEV_MGMTDEV_MAX_VQS,		/* u32 */
-- 
2.34.1