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. >
