[ kvm-Bugs-2413430 ] CPU: Linux guests fails on emulated "core2duo" and "coreduo"

* [ kvm-Bugs-2413430 ] CPU: Linux guests fails on emulated "core2duo" and "coreduo"
@ 2009-01-21 12:53 SourceForge.net
  0 siblings, 0 replies; 6+ messages in thread
From: SourceForge.net @ 2009-01-21 12:53 UTC (permalink / raw)
  To: noreply

Bugs item #2413430, was opened at 2008-12-10 11:00
Message generated for change (Settings changed) made by technologov
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=893831&aid=2413430&group_id=180599

Please note that this message will contain a full copy of the comment thread,
including the initial issue submission, for this request,
not just the latest update.
Category: None
Group: None
>Status: Open
Resolution: Fixed
Priority: 5
Private: No
Submitted By: Technologov (technologov)
Assigned to: Amit Shah (amitshah)
Summary: CPU: Linux guests fails on emulated "core2duo" and "coreduo"

Initial Comment:

Host: Intel Core i7 740, Fedora10, x64, KVM-80, EPT=off
Guests: Fedora10/32, SUSE-10.3/32

Both guests fail to boot - stuck on init stage if I start the VMs with an emulated "core2duo" and "coreduo" CPUID.

Command:
qemu-kvm -hda openSUSE-10.3.vmdk -m 512 -cpu core2duo

However the same guests work with "pentium3" cpu.

----------------------------------------------------------------------

>Comment By: Technologov (technologov)
Date: 2009-01-21 14:53

Message:
Yes, it indeed works now with KVM-83+:
(ca15def2f46c94cbaeba746d5049bc8e64202237)

./qemu-kvm -hda Fedora10-x64.qcow2 -m 512 -cpu core2duo

Host: F7/x64, Intel Core 2 Duo, KVM-83+

Fedora 10 guest output:

[user@localhost ~]$ cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 15
model name      : Intel(R) Core(TM)2 Duo CPU     T7700  @ 2.40GHz
stepping        : 11
cpu MHz         : 1596.085
cache size      : 32 KB
fpu             : yes
fpu_exception   : yes
cpuid level     : 10
wp              : yes
flags           : fpu de pse tsc msr pae mce cx8 apic sep mtrr pge mca
cmov pat
pse36 clflush mmx fxsr sse sse2 syscall nx lm constant_tsc up rep_good
nopl pni monitor ssse3
bogomips        : 3192.17
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management:

-Alexey

----------------------------------------------------------------------

Comment By: Amit Shah (amitshah)
Date: 2009-01-16 17:07

Message:
This is fixed in commit 4773ce3ff932440e6585829ba2df9d34a817e17e

It will be released with kvm-84

----------------------------------------------------------------------

Comment By: Technologov (technologov)
Date: 2009-01-13 15:33

Message:
Here is my email & reply from Alexander Graf of Novell:

Hi Alexey,

Alexey Eromenko wrote:
> Hello Dear Alexander Graf !
>
> In one of your patches you included the option to emulate Core2Duo and
CoreDuo CPUs in Qemu/KVM.
>  
> However those CPUs do not work as expected and lead to failures with KVM
with Linux guests.
>
> Details:
>
http://sourceforge.net/tracker/index.php?func=detail&aid=2413430&group_id=180599&atid=893831
>
> Could you please take a look at it?
>
> Thanks in advance,
> -Alexey
>   
Yes, apparently nobody really cares about CPUID4. That is broken in KVM
and qemu's new KVM implementation pretty badly and hangs every OS on
bootup.

I sent some patches to work around the problem some time ago (read:
about a year), but they were not accepted because a new interface was in
the works, which it still is.

So yes, implementing CPUID4 support is on my TODO-list, but it's not on
the highest priority, sorry. If you want it to work, take the CPUID
patch from the SUSE source RPM and apply it to your build of KVM.

Alex 
5.Jan.2009.

----------------------------------------------------------------------

Comment By: Technologov (technologov)
Date: 2008-12-10 14:46

Message:
NOTE 1: "core2duo" and "coreduo" CPUID work with KVM with Windows XP
guest.

NOTE 2: "core2duo" and "coreduo" CPUID work with -no-kvm even with Linux
guests.
That is - Qemu will work - just KVM fails.

----------------------------------------------------------------------

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=893831&aid=2413430&group_id=180599

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