ethtool: rss: report info about additional contexts from XArray

IOCTL already uses the XArray when reporting info about additional
contexts. Do the same thing in netlink code.
Reviewed-by: Edward Cree <ecree.xilinx@gmail.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ethtool/rss.c

@@ -82,7 +82,6 @@ rss_prepare_get(const struct rss_req_info *request, struct net_device *dev,
 	rxfh.indir = data->indir_table;
 	rxfh.key_size = data->hkey_size;
 	rxfh.key = data->hkey;
-	rxfh.rss_context = request->rss_context;
 
 	ret = ops->get_rxfh(dev, &rxfh);
 	if (ret)
@@ -95,6 +94,41 @@ rss_prepare_get(const struct rss_req_info *request, struct net_device *dev,
 	return ret;
 }
 
+static int
+rss_prepare_ctx(const struct rss_req_info *request, struct net_device *dev,
+		struct rss_reply_data *data, const struct genl_info *info)
+{
+	struct ethtool_rxfh_context *ctx;
+	u32 total_size, indir_bytes;
+	u8 *rss_config;
+
+	ctx = xa_load(&dev->ethtool->rss_ctx, request->rss_context);
+	if (!ctx)
+		return -ENOENT;
+
+	data->indir_size = ctx->indir_size;
+	data->hkey_size = ctx->key_size;
+	data->hfunc = ctx->hfunc;
+	data->input_xfrm = ctx->input_xfrm;
+
+	indir_bytes = data->indir_size * sizeof(u32);
+	total_size = indir_bytes + data->hkey_size;
+	rss_config = kzalloc(total_size, GFP_KERNEL);
+	if (!rss_config)
+		return -ENOMEM;
+
+	data->indir_table = (u32 *)rss_config;
+	memcpy(data->indir_table, ethtool_rxfh_context_indir(ctx), indir_bytes);
+
+	if (data->hkey_size) {
+		data->hkey = rss_config + indir_bytes;
+		memcpy(data->hkey, ethtool_rxfh_context_key(ctx),
+		       data->hkey_size);
+	}
+
+	return 0;
+}
+
 static int
 rss_prepare_data(const struct ethnl_req_info *req_base,
 		 struct ethnl_reply_data *reply_base,
@@ -115,6 +149,7 @@ rss_prepare_data(const struct ethnl_req_info *req_base,
 			return -EOPNOTSUPP;
 
 		data->no_key_fields = !ops->rxfh_per_ctx_key;
+		return rss_prepare_ctx(request, dev, data, info);
 	}
 
 	return rss_prepare_get(request, dev, data, info);