do
	{
	  if (n_alloc < sz)
	    n_alloc +=
	      vlib_buffer_alloc (vm, vring->indirect_buffers + n_alloc,
				 sz - n_alloc);
	}
      while (n_alloc != sz);

 in /opt/vpp-agent/dev/vpp/src/vlib/buffer_funcs.h
(gdb) info args
vm = 0x7fb2e0fc4a40 <vlib_global_main>
buffers = 0x7fb2a000724c
n_buffers = 0
buffer_pool_index = 0 '\000'