diff --git a/Documentation/netlink/specs/ethtool.yaml b/Documentation/netlink/specs/ethtool.yaml
index 259cb211a338..655d8d10fe24 100644
--- a/Documentation/netlink/specs/ethtool.yaml
+++ b/Documentation/netlink/specs/ethtool.yaml
@@ -1524,7 +1524,8 @@ attribute-sets:
         nested-attributes: bitset
       -
         name: hwtstamp-flags
-        type: u32
+        type: nest
+        nested-attributes: bitset
 
 operations:
   enum-model: directional
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index d1089b88efc7..9b18c4cfe56f 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -682,6 +682,7 @@ enum ethtool_link_ext_substate_module {
  * @ETH_SS_STATS_ETH_CTRL: names of IEEE 802.3 MAC Control statistics
  * @ETH_SS_STATS_RMON: names of RMON statistics
  * @ETH_SS_STATS_PHY: names of PHY(dev) statistics
+ * @ETH_SS_TS_FLAGS: hardware timestamping flags
  *
  * @ETH_SS_COUNT: number of defined string sets
  */
@@ -708,6 +709,7 @@ enum ethtool_stringset {
 	ETH_SS_STATS_ETH_CTRL,
 	ETH_SS_STATS_RMON,
 	ETH_SS_STATS_PHY,
+	ETH_SS_TS_FLAGS,
 
 	/* add new constants above here */
 	ETH_SS_COUNT
diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index 2bd77c94f9f1..d88e9080643b 100644
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -462,6 +462,11 @@ const char ts_rx_filter_names[][ETH_GSTRING_LEN] = {
 };
 static_assert(ARRAY_SIZE(ts_rx_filter_names) == __HWTSTAMP_FILTER_CNT);
 
+const char ts_flags_names[][ETH_GSTRING_LEN] = {
+	[const_ilog2(HWTSTAMP_FLAG_BONDED_PHC_INDEX)] = "bonded-phc-index",
+};
+static_assert(ARRAY_SIZE(ts_flags_names) == __HWTSTAMP_FLAG_CNT);
+
 const char udp_tunnel_type_names[][ETH_GSTRING_LEN] = {
 	[ETHTOOL_UDP_TUNNEL_TYPE_VXLAN]		= "vxlan",
 	[ETHTOOL_UDP_TUNNEL_TYPE_GENEVE]	= "geneve",
diff --git a/net/ethtool/common.h b/net/ethtool/common.h
index 850eadde4bfc..58e9e7db06f9 100644
--- a/net/ethtool/common.h
+++ b/net/ethtool/common.h
@@ -13,6 +13,7 @@
 	ETHTOOL_LINK_MODE_ ## speed ## base ## type ## _ ## duplex ## _BIT
 
 #define __SOF_TIMESTAMPING_CNT (const_ilog2(SOF_TIMESTAMPING_LAST) + 1)
+#define __HWTSTAMP_FLAG_CNT (const_ilog2(HWTSTAMP_FLAG_LAST) + 1)
 
 struct link_mode_info {
 	int				speed;
@@ -38,6 +39,7 @@ extern const char wol_mode_names[][ETH_GSTRING_LEN];
 extern const char sof_timestamping_names[][ETH_GSTRING_LEN];
 extern const char ts_tx_type_names[][ETH_GSTRING_LEN];
 extern const char ts_rx_filter_names[][ETH_GSTRING_LEN];
+extern const char ts_flags_names[][ETH_GSTRING_LEN];
 extern const char udp_tunnel_type_names[][ETH_GSTRING_LEN];
 
 int __ethtool_get_link(struct net_device *dev);
diff --git a/net/ethtool/strset.c b/net/ethtool/strset.c
index 818cf01f0911..6b76c05caba4 100644
--- a/net/ethtool/strset.c
+++ b/net/ethtool/strset.c
@@ -75,6 +75,11 @@ static const struct strset_info info_template[] = {
 		.count		= __HWTSTAMP_FILTER_CNT,
 		.strings	= ts_rx_filter_names,
 	},
+	[ETH_SS_TS_FLAGS] = {
+		.per_dev	= false,
+		.count		= __HWTSTAMP_FLAG_CNT,
+		.strings	= ts_flags_names,
+	},
 	[ETH_SS_UDP_TUNNEL_TYPES] = {
 		.per_dev	= false,
 		.count		= __ETHTOOL_UDP_TUNNEL_TYPE_CNT,
diff --git a/net/ethtool/tsconfig.c b/net/ethtool/tsconfig.c
index 2dc3a3b76615..4e8fd4f5c27b 100644
--- a/net/ethtool/tsconfig.c
+++ b/net/ethtool/tsconfig.c
@@ -54,7 +54,7 @@ static int tsconfig_prepare_data(const struct ethnl_req_info *req_base,
 
 	data->hwtst_config.tx_type = BIT(cfg.tx_type);
 	data->hwtst_config.rx_filter = BIT(cfg.rx_filter);
-	data->hwtst_config.flags = BIT(cfg.flags);
+	data->hwtst_config.flags = cfg.flags;
 
 	data->hwprov_desc.index = -1;
 	hwprov = rtnl_dereference(dev->hwprov);
@@ -91,10 +91,16 @@ static int tsconfig_reply_size(const struct ethnl_req_info *req_base,
 
 	BUILD_BUG_ON(__HWTSTAMP_TX_CNT > 32);
 	BUILD_BUG_ON(__HWTSTAMP_FILTER_CNT > 32);
+	BUILD_BUG_ON(__HWTSTAMP_FLAG_CNT > 32);
 
-	if (data->hwtst_config.flags)
-		/* _TSCONFIG_HWTSTAMP_FLAGS */
-		len += nla_total_size(sizeof(u32));
+	if (data->hwtst_config.flags) {
+		ret = ethnl_bitset32_size(&data->hwtst_config.flags,
+					  NULL, __HWTSTAMP_FLAG_CNT,
+					  ts_flags_names, compact);
+		if (ret < 0)
+			return ret;
+		len += ret;	/* _TSCONFIG_HWTSTAMP_FLAGS */
+	}
 
 	if (data->hwtst_config.tx_type) {
 		ret = ethnl_bitset32_size(&data->hwtst_config.tx_type,
@@ -130,8 +136,10 @@ static int tsconfig_fill_reply(struct sk_buff *skb,
 	int ret;
 
 	if (data->hwtst_config.flags) {
-		ret = nla_put_u32(skb, ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS,
-				  data->hwtst_config.flags);
+		ret = ethnl_put_bitset32(skb, ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS,
+					 &data->hwtst_config.flags, NULL,
+					 __HWTSTAMP_FLAG_CNT,
+					 ts_flags_names, compact);
 		if (ret < 0)
 			return ret;
 	}
@@ -180,7 +188,7 @@ const struct nla_policy ethnl_tsconfig_set_policy[ETHTOOL_A_TSCONFIG_MAX + 1] =
 	[ETHTOOL_A_TSCONFIG_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
 	[ETHTOOL_A_TSCONFIG_HWTSTAMP_PROVIDER] =
 		NLA_POLICY_NESTED(ethnl_ts_hwtst_prov_policy),
-	[ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS] = { .type = NLA_U32 },
+	[ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS] = { .type = NLA_NESTED },
 	[ETHTOOL_A_TSCONFIG_RX_FILTERS] = { .type = NLA_NESTED },
 	[ETHTOOL_A_TSCONFIG_TX_TYPES] = { .type = NLA_NESTED },
 };
@@ -296,6 +304,7 @@ static int ethnl_set_tsconfig(struct ethnl_req_info *req_base,
 
 	BUILD_BUG_ON(__HWTSTAMP_TX_CNT > 32);
 	BUILD_BUG_ON(__HWTSTAMP_FILTER_CNT > 32);
+	BUILD_BUG_ON(__HWTSTAMP_FLAG_CNT > 32);
 
 	if (!netif_device_present(dev))
 		return -ENODEV;
@@ -377,9 +386,13 @@ static int ethnl_set_tsconfig(struct ethnl_req_info *req_base,
 	}
 
 	if (tb[ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS]) {
-		ethnl_update_u32(&hwtst_config.flags,
-				 tb[ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS],
-				 &config_mod);
+		ret = ethnl_update_bitset32(&hwtst_config.flags,
+					    __HWTSTAMP_FLAG_CNT,
+					    tb[ETHTOOL_A_TSCONFIG_HWTSTAMP_FLAGS],
+					    ts_flags_names, info->extack,
+					    &config_mod);
+		if (ret < 0)
+			goto err_free_hwprov;
 	}
 
 	ret = net_hwtstamp_validate(&hwtst_config);
