Xen users - Jul 2014 - Xl mem-max does nothing

Hello,

Today we updated one of our Dom0 from Xen 4.1 (xm) to Xen 4.4 (xl).

Everything seems good, exept DomU max memory setting.

With xm, we had in DomU .cfg :

  maxmem = 256
  memory = 256

And we could change it live with

  xm mem-max vmname 512
  xm mem-set vmname 512

Worked like a charm.

Now with xl, same DomU .cfg,

  xl mem-max vmname 512

does nothing (but gives no error) and, of course,

  xl mem-set vmname 512

give an error (libxl: error: libxl.c:4097:libxl_set_memory_target:
memory_dynamic_max must be less than or equal to memory_static_max).

The DomU is the same as before, and both Dom0 and DomU kernels are up
to date (3.15.6) with memory hotplug and memory ballooning compiled
in.

Is it a known error/xl regression/"feature", or is it supposed to work
with xl like xm ?

Tanks,

Neri