Re: [Qemu-devel] [PATCH 0/6] Fix -kernel with SeaBIOS v2

[Alexander Graf]

Christoph Hellwig wrote:
> On Thu, Nov 26, 2009 at 01:00:25PM +0100, Alexander Graf wrote:
>   
>> Hm - are you using -L pc-bios?
>>     
>
> No.  I use an installed qemu (./configure --prefix=/opt/qemu) and
> there's no pc-bios directorie in my kernel source tree where I start it
> from.
>   

Hm - maybe worth a try to give it a -L to the source pc-bios directory
anyways.

>> Also, maybe there's something in dmesg
>> telling you about an invalid instruction or the likes?
>>     
>
> [ 5928.948615] kvm: 14584: cpu0 unhandled wrmsr: 0xc0000083 data 0
> [ 5929.309486] kvm: 14584: cpu0 unhandled wrmsr: 0xc0000083 data 0
> [ 5929.309530] kvm: 14584: cpu0 unhandled rdmsr: 0xc0000083
> [ 5929.311763] kvm: 14584: cpu0 unhandled wrmsr: 0xc0000083 data 0
> [ 5929.311856] kvm: 14584: cpu0 unhandled wrmsr: 0xc0000083 data 0
> [ 5929.311899] kvm: 14584: cpu0 unhandled rdmsr: 0xc0000083
> [ 5929.313408] kvm: 14584: cpu0 unhandled wrmsr: 0xc0000083 data 0
>   

/include/asm/msr-index.h:#define MSR_CSTAR        0xc0000083 /* compat
mode SYSCALL target */

Sounds like your guest kernel is trying to access an x86_64 register?

You can of cause try insmod'ing kvm.ko with ignore_msrs=1. You hopefully
don't need syscalls until you get into user space.

Alex