Re: regression in v3.9? a guest stuck in BIOS if emulate_invalid_guest_state=Y

["Jun'ichi Nomura" <j-nomura@ce.jp.nec.com>]

On 05/07/13 23:46, Paolo Bonzini wrote:
> Il 07/05/2013 14:06, Gleb Natapov ha scritto:
>> On Tue, May 07, 2013 at 08:05:27PM +0900, Jun'ichi Nomura wrote:
>>> On 05/07/13 19:35, Gleb Natapov wrote:
>>>> On Tue, May 07, 2013 at 06:55:23PM +0900, Jun'ichi Nomura wrote:
>>>>> With v3.9 kernel and Nehalem CPU (i.e. unrestricted_guest=N),
>>>>> a guest stuck during boot (seemingly in BIOS).
>>>>> When setting emulate_invalid_guest_state=0, it does boot.
>>>>> (With v3.8 kernel and older, the guest used to boot fine by default.)
>>>>>
>>>>> The userspace is qemu-kvm of RHEL6.
>>>>> It seems the guest boots up fine with upstream qemu 1.4.1.
>>>>>
>>>>> Is this a kernel bug? Or is the userspace just too old to run on v3.9?
>>>>>
>>>>>
>>>> It should work. What seabios version are you using?
>>>
>>> It's seabios-0.6.1.2-26.el6.
>>> (and qemu-kvm-0.12.1.2-2.355.el6)
>>>
>> Works for me, but it looks like in your case the bios is in option rom.
> 
> What version of vgabios, too?

vgabios-0.6b-3.7.el6
sgabios-bin-0-0.3.20110621svn.el6

>> What are you booting from? What's the qemu command line?

>From disk image.

Command line is like this:
  /usr/libexec/qemu-kvm -name vm12 -S -M rhel6.3.0 -enable-kvm -m 1024 -smp 2,sockets=2,cores=1,threads=1 -uuid 539b7cdb-7afc-4237-bdbc-8ddbdf5e0204 -nographic -nodefconfig -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/vm12.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-shutdown -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -drive file=/dev/kvmvg/vm12,if=none,id=drive-virtio-disk0,format=raw,cache=none,aio=native -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x4,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3

When I edit VM definition so that qemu-kvm is invoked without '-nographic',
the guest boots fine.

>> What is the output of "virsh qemu-monitor-command vm12 --hmp x/i $pc"
>> when it hangs?

# virsh qemu-monitor-command vm12 --hmp x/4i \$pc
0x00000000000c06ca:  aam    $0xa
0x00000000000c06cc:  mov    %ax,%bx
0x00000000000c06ce:  mov    %bh,%al
0x00000000000c06d0:  aam    $0xa

# virsh qemu-monitor-command vm12 --hmp x/8b \$pc
00000000000c06ca: 0xd4 0x0a 0x89 0xc3 0x88 0xf8 0xd4 0x0a

-- 
Jun'ichi Nomura, NEC Corporation