Comment # 2 on bug 1209245 from Olaf Hering

When running a xen-4.14.5_08-150300.3.40.1 dom0 and domU kernel
4.12.14-122.127.1, domU kdump works with 'echo c > /proc/sysrq-trigger'.

When running a xen-4.16.3_04-150400.4.22.1 dom0 and domU kernel
4.12.14-122.127.1, this is reported in xl dmesg after 'echo c >
/proc/sysrq-trigger' in domU:

(XEN) d2 has active grant 0 (MFN: 0x10540ba)