CentOS - May 2020 - kvm: C8 as guest on C6 host / huge delay while booting

Since C8.1  kvm guests have a huge delay while booting on a kvm host 
based on C6. This delay was not present with C8.0. The "pause" happend
direct after the grub step. The VNC session shows only a "_"
character.

Any ideas what changes?

--
Leon

Am 11.05.20 um 15:59 schrieb Leon Fauster:
> Since C8.1? kvm guests have a huge delay while booting on a kvm host 
> based on C6. This delay was not present with C8.0. The "pause"
happend
> direct after the grub step. The VNC session shows only a "_"
character.
> 
and this are the corresponding logs. The guest system continues to boot 
after ~5 minutes. At that point this appears

May 16 16:44:14 ev kernel: kvm: 8458: cpu0 unhandled rdmsr: 0x140
May 16 16:44:14 ev kernel: kvm: 8458: cpu0 disabled perfctr wrmsr: 0xc2 
data 0xffff
May 16 16:44:14 ev kernel: kvm: 8458: cpu1 unhandled rdmsr: 0x140
May 16 16:44:14 ev kernel: kvm: 8458: cpu2 unhandled rdmsr: 0x140
May 16 16:44:14 ev kernel: kvm: 8458: cpu3 unhandled rdmsr: 0x140
May 16 16:44:15 ev kernel: kvm: emulating exchange as write

Any ideas?

--
Leon

On May 16, 2020 6:09:22 PM GMT+03:00, Leon Fauster via CentOS <centos at
centos.org> wrote:
>Am 11.05.20 um 15:59 schrieb Leon Fauster:
>> Since C8.1? kvm guests have a huge delay while booting on a kvm host 
>> based on C6. This delay was not present with C8.0. The
"pause"
>happend
>> direct after the grub step. The VNC session shows only a "_"
>character.
>> 
>
>and this are the corresponding logs. The guest system continues to boot
>
>after ~5 minutes. At that point this appears
>
>May 16 16:44:14 ev kernel: kvm: 8458: cpu0 unhandled rdmsr: 0x140
>May 16 16:44:14 ev kernel: kvm: 8458: cpu0 disabled perfctr wrmsr: 0xc2
>
>data 0xffff
>May 16 16:44:14 ev kernel: kvm: 8458: cpu1 unhandled rdmsr: 0x140
>May 16 16:44:14 ev kernel: kvm: 8458: cpu2 unhandled rdmsr: 0x140
>May 16 16:44:14 ev kernel: kvm: 8458: cpu3 unhandled rdmsr: 0x140
>May 16 16:44:15 ev kernel: kvm: emulating exchange as write
>
>Any ideas?
>
>--
>Leon
>_______________________________________________
>CentOS mailing list
>CentOS at centos.org
>https://lists.centos.org/mailman/listinfo/centos
What is the output of:
systemd-analyze  blame
systemd-analyze  critical-chain
systemd-analyze  plot >  somefile

Best Regards,
Strahil Nikolov

On 5/16/20 5:09 PM, Leon Fauster via CentOS wrote:
> Am 11.05.20 um 15:59 schrieb Leon Fauster:
>> Since C8.1? kvm guests have a huge delay while booting on a kvm host
based on C6. This delay was not present with C8.0. The "pause" happend
>> direct after the grub step. The VNC session shows only a "_"
character.
>>
> 
> and this are the corresponding logs. The guest system continues to boot
after ~5 minutes. At that point this appears
> 
> May 16 16:44:14 ev kernel: kvm: 8458: cpu0 unhandled rdmsr: 0x140
> May 16 16:44:14 ev kernel: kvm: 8458: cpu0 disabled perfctr wrmsr: 0xc2
data 0xffff
> May 16 16:44:14 ev kernel: kvm: 8458: cpu1 unhandled rdmsr: 0x140
> May 16 16:44:14 ev kernel: kvm: 8458: cpu2 unhandled rdmsr: 0x140
> May 16 16:44:14 ev kernel: kvm: 8458: cpu3 unhandled rdmsr: 0x140
> May 16 16:44:15 ev kernel: kvm: emulating exchange as write
> 
> Any ideas?
> 
> -- 
> Leon
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> https://lists.centos.org/mailman/listinfo/centos
looks like a mismatch between the hardware that the KVM guest is told to use,
and the actual hardware provided by the host.

You can change the CPU type that the guest expects.

HTH
Kay