You are right, is KVM's bug.
But this was fixed on -snapshots right?
If so, OpenBSD 6.4 would work well, bypassing KVM's bug.

Cheers.
Elias.

2018-08-07 16:27 GMT-03:00 Theo de Raadt <[email protected]>:
> We don't agree.
>
> We consider it a bug in KVM.
>
> Doesn't KVM suggest they are emulating a real machine?  AMD has
> documented that MSR.  So KVM should emulate the MSR.  In some
> way, even perhaps act like it is a NOP.
>
> Or they shouldn't claim to be that CPU.
>
> Feel free to report to those other upstreams.
>
> Elias M. Mariani <[email protected]> wrote:
>> Sorry to keep pinging this one.
>> If you install OPENBSD_6_3 in KVM/QEMU and run syspatch and apply the
>> LFENCE patch the machine redeems unable to boot.
>> I think that this should be another patch to fix the problem, anyone
>> using a OpenBSD virtual server with that config will ruin the boot
>> process with the patches.
>>
>> Cheers.
>> Elias.
>>
>> 2018-08-04 16:47 GMT-03:00 Elias M. Mariani <[email protected]>:
>> > Hi Mike,
>> > I saw the changes in source about this from Bryan.
>> > This also hit OPENBSD_63 from a patch.
>> > Shouldn't be a another patch or something ?
>> >
>> > Cheers.
>> > Elias.
>> >
>> > 2018-08-01 13:23 GMT-03:00 Mike Larkin <[email protected]>:
>> >> On Wed, Aug 01, 2018 at 12:04:55AM -0300, Elias M. Mariani wrote:
>> >>> (sorry, I forgot to add the list)
>> >>> Here you go.
>> >>> Cheers.
>> >>>
>> >>> 2018-07-31 20:47 GMT-03:00 Mike Larkin <[email protected]>:
>> >>> > On Tue, Jul 31, 2018 at 04:43:22PM -0700, Mike Larkin wrote:
>> >>> >> On Tue, Jul 31, 2018 at 04:59:54PM -0300, Elias M. Mariani wrote:
>> >>> >> > And segmentation fault after applying the patches on OPENBSD_63.
>> >>> >> > Maybe is just a coincidence, according to the data:
>> >>> >> > HOST: ubuntu
>> >>> >> > QEMU: Running OPENBSD_63 + patches
>> >>> >> > (was working OK until patched).
>> >>> >> >
>> >>> >> > Cheers.
>> >>> >> > Elias.
>> >>> >> >
>> >>> >> > 2018-07-31 16:36 GMT-03:00 Elias M. Mariani 
>> >>> >> > <[email protected]>:
>> >>> >> > > Trying to boot in QEMU from snapshots/amd64/cd63.iso or from
>> >>> >> > > snapshots/amd64/bsd.rd from the current disk:
>> >>> >> > > The booting starts but the machine gets rebooted almost 
>> >>> >> > > immediately.
>> >>> >> > >
>> >>> >> > > I'm reporting this pretty bad. But is because I'm using 6.3 in 
>> >>> >> > > that
>> >>> >> > > cloud server and just wanted to test if the snapshot was booting
>> >>> >> > > correctly. QEMU is running in godsknowswhat.
>> >>> >> > > I have never used QEMU myself, could someone try to reproduce ?
>> >>> >> > > using cd63.iso from OPENBSD_63 gives no problems.
>> >>> >> > >
>> >>> >> > > Cheers.
>> >>> >> > > Elias.
>> >>> >>
>> >>> >>
>> >>> >> This may be related to the recent speculation/lfence fix that went in
>> >>> >> a week or so ago. It reads an MSR that should be present on that CPU 
>> >>> >> (and
>> >>> >> if it isn't, we won't read it).
>> >>> >>
>> >>> >> I have one of those same Opterons here, I'll update it to -current 
>> >>> >> and see
>> >>> >> if I can repro this on real hardware. My guess is that kvm is failing 
>> >>> >> the
>> >>> >> RDMSR because the knowledge of it post-dates the time that kvm was 
>> >>> >> built.
>> >>> >>
>> >>> >> -ml
>> >>> >>
>> >>> >
>> >>> > PS, "show registers" at ddb> prompt would confirm that is indeed this 
>> >>> > fix,
>> >>> > if you could do that and report the output it would be appreciated.
>> >>> >
>> >>
>> >> Yes, this is related to the change I thought. I still haven't had a 
>> >> chance to
>> >> check on real hardware yet, though.
>>

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