------ Wiadomość oryginalna ------
*Temat: *Re: Openbsd 6.1 and Current Console Freezes and lockup Proxmox PVE5.0
*Nadawca: *Mike Larkin <mlar...@azathoth.net>
*Adresat: *Michał Koc <m...@prime.pl>
*Kopia: *misc@openbsd.org
*Data: *19.10.2017 08:36
On Fri, Oct 13, 2017 at 11:05:12PM +0200, Michał Koc wrote:
On Thu, Oct 12, 2017 at 03:11:31PM -0700, Mike Larkin wrote:
On Thu, Oct 12, 2017 at 10:36:42PM +0200, Michał Koc wrote:
On Thu, Oct 12, 2017 at 01:23:36PM +0200, Michał Koc wrote:
On Sun, Oct 08, 2017 at 11:59:52PM +0200, Oliver Marugg wrote:
On 7 Oct 2017, at 22:01, Mike Larkin wrote:

On Sat, Oct 07, 2017 at 02:19:58PM +0200, Oliver Marugg wrote:
Just to add a 4th situation of hangs: Login via proxmox (pve)/kvm
serial
console (via noVNC), login successful: Vm guest in pve hangs, cpu
usage at
above 102%. Only way is to hard stop the Vm guest. -oliver

sounds like a kvm bug. Ask your provider to investigate the host side
when this
happens.
Thanks Mike, will do so. The proxmox guys have also the idea that it could
be a bug in kvm hypervisor (which is the hypervisor part for proxmox) and
will affect OpenBSD since 4.9, they wrote me in their public forum. As far
as I understood they do not know what OpenBSD needs in kvm or what/where
should be fixed in kvm run OpenBSD without that freezes.

-oliver
>From what I read, the cpu spins to 100%, which means somewhere on the host it's
likely spinning also. Start with systrace/ptrace/ktrace/whatever on the host
qemu-kvm and go from there...

-ml



Hi,

it looks like the cpu process of kvm (CPU 0/KVM) is issuing 1500+ of
ioctl(15, KVM_RUN, 0)  per second while running OpenBSD 6.2 guest.

What CPU profile is being presented to the OpenBSD guest?

I've seen things like this happen when a vCPU is claimed to have monitor/mwait
support, but the hypervisor implements those as NOPs, which just results in
spinning like this.

In short - try changing the type of CPU presented to the guest and see if that
changes behaviour. At least then you'll have more data points to work with.

-ml
Okey,
How would You disable monitor/mwait support in KVM to be presented to guest
?

Well, monitor/mwait was just what I recall contributing to something *like*
this.

PS, IIRC qemu -cpu ? will show you a list of recognized cpuid flags, from
which you can subtract off things you don't want.
Hi Mike,

Guest OpenBSD has those flags presented:
cpu0: FPU,VME,DE,PSE,TSC,MSR,MCE,CX8,APIC,MMX,HV,PERF

What else should I switch off to get desired effect ?

Those flags are completely bizarre. Compare to vmm(4):

cpu0: 
FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,MMX,FXSR,SSE,SSE2,SSE3,PCLMUL,SSSE3,CX16,SSE4.1,SSE4.2,POPCNT,AES,XSAVE,AVX,F16C,RDRAND,HV,NXE,RDTSCP,LONG,LAHF,ITSC,FSGSBASE,SMEP,ERMS

>From what you said above, proxmox doesn't even expose PAE or PGE, which means
it's emulating something like a 1990s era 80486 CPU. It doesn't even claim to
support LONG, which means no 64 bit mode either.

It sounds like whatever hypervisor you are using is completely messed up. You
need to take this up with the proxmox or KVM people.

-ml


Hi Mike,

after some fiddling around with various setting it looks like setting machine in <type arch='x86_64' machine='pc-q35-2.8'>hvm</type> to q35 solves the problem at least partially.

The host cpu consumption in below 2% and I cannot see any hangs. Even under heavy cpu load.

BR
M.K.


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