On 22/01/2019 09:52, Jan Beulich wrote: >>>> On 22.01.19 at 09:06, <jgross@xxxxxxxx> wrote: >> Don't allow memory to be added above the allowed maximum allocation >> limit set by Xen. > > This reads as if the hypervisor was imposing a limit here, but looking at > xen_get_max_pages(), xen_foreach_remap_area(), and > xen_count_remap_pages() I take it that it's a restriction enforced by > the Xen subsystem in Linux. Furthermore from the cover letter I imply > that the observed issue was on a Dom0, yet xen_get_max_pages()'s > use of XENMEM_maximum_reservation wouldn't impose any limit there > at all (without use of the hypervisor option "dom0_mem=max:..."), > would it? Oh yes, you are right, of course! I need to check the current reservation and adjust the allowed limit in case of ballooning and/or memory hotplug. Thanks for noticing that! Juergen
