From: Nikola Ciprich Sent: October 28, 2018 at 5:52:59 PM GMT > To: kvm@xxxxxxxxxxxxxxx > Cc: nik@xxxxxxxxxxx > Subject: after switching host from 4.14 to 4.19 linux guests are crashing after migration > > > Hi, > > after upgrading my host to 4.19 kernel, I noticed there's high chance > linux guests will crash during/after migration (from 4.14.x host) > > backtraces are always similar: > > http://nik.lbox.cz/download/crash1.png > http://nik.lbox.cz/download/crash2.png > > (sorry for screenshots, hope it's OK) > > host is x86_64 centos 7, running qemu-kvm-2.12.0 / qemu-kvm-2.12.0 > > any idea where the problem could be? > > if I could provide any further info, please let me know You probably have one machine with the latest Intel firmware, which includes protection against Spectre v2, and another that does not. You try to migrate a VM from one that has protection to one which is not patched. Try to load the latest microcode patch to the machine to which you try to migrate to. Check /sys/devices/system/cpu/vulnerabilities/spectre_v2 to ensure IBPB is supported on that machine. Regards, Nadav
