Hello,
Sure, no problem. I've gathered the information requested. It's
accessible on my web space:
Environment details and guest XML:
http://45.63.6.248/kvm1/env.txt
KVM traces at requested intervals:
http://45.63.6.248/kvm1/trace-01-boot.tar.gz
http://45.63.6.248/kvm1/trace-02-2sec.tar.gz
http://45.63.6.248/kvm1/trace-03-4sec.tar.gz
Best,
Andrew
On 12/27/2017 3:38 PM, Paolo Bonzini wrote:
On 27/12/2017 19:55, Andrew Davis wrote:
In a nutshell:
* OpenBSD dev claims QEMU/KVM local APIC emulation is broken.
* OpenBSD dev states that OpenBSD uses local APIC to interrupt every
10ms in "repeated mode".
* OpenBSD dev claims that other systems (Linux, FreeBSD) likely do not
use the local APIC in "repeated mode".
I'm not familiar enough with low-level development to verify or confirm
these claims.
I've tried tweaking some different settings on the guest and host, such
as disabling the HPET timer and x2apic, neither of which has proven
effective.
Adding "kvm-intel.preemption_timer=0" on the host kernel commandline
seems to resolve the timing issue. However, I had at least one host that
wouldn't reboot cleanly with this flag enabled.
Ok, this is interesting. Please gather a trace using
trace-cmd record -e kvm -c -P pid-of-qemu
for about 10 seconds; run it once right after booting, once when it
starts taking 2 seconds, one when it starts taking 4 seconds.
The traces are big but should compress well.
Thanks,
Paolo
This is only an issue on OpenBSD. Other guest operating systems (CentOS,
Ubuntu, FreeBSD) on the same machine do not exhibit this behavior.
