Hi Juergen,
I love your patch! Yet something to improve:
[auto build test ERROR on xen-tip/linux-next]
[also build test ERROR on linux/master linus/master v5.15-rc7 next-20211029]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use
alloc_xenballooned_pages() and free_xenballooned_pages() are used as
direct replacements of xen_alloc_unpopulated_pages() and
xen_free_unpopulated_pages() in case CONFIG_XEN_UNPOPULATED_ALLOC isn't
defined.
Guard both functions with !CONFIG_XEN_UNPOPULATED_ALLOC and rename them
to the xen_*() vari