No-one.
The tariffs and retaliatory tariffs will increase the cost of goods for ordinary people, either through higher priced imports or the need to switch to higher priced local products.
With increasing import prices, businesses will lose out as demand for products decreases. There are also increased supply costs if tariffs are on raw materials.
Some businesses may cut jobs leading to increased unemployment and higher levels of benefit spend for governments.
Governments may receive an increase in import taxes but this will depend on whether the increased tariffs more than outweigh the reduction in (higher-prices) imports.
Generally trade wars are lose-lose.