KVM bug

KVM bug

[Saksena, Abhishek]

Hi 
I am trying to boot a patched version of Boch's BIOS on KVM. It works fine with Qemu with -no-kvm option. However I get following with KVM 


unhandled vm exit: 0x80000021 vcpu_id 0
rax 0000000000000000 rbx 000000000000133a rcx 0000000000000000 rdx 0000000000000008
rsi 0000000000000008 rdi 0000000000000008 rsp 00000000000011a4 rbp 00000000000011bc
r8  0000000000000000 r9  0000000000000000 r10 0000000000000000 r11 0000000000000000
r12 0000000000000000 r13 0000000000000000 r14 0000000000000000 r15 0000000000000000
rip 00000000000007ca rflags 00023046
cs f000 (000f0000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
ds 88f9 (00088f9b/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
es 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
ss c181 (000c1810/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
fs 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
gs 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
tr 0000 (fffbd000/00002088 p 1 dpl 0 db 0 s 0 type b l 0 g 0 avl 0)
ldt 0000 (00000000/0000ffff p 1 dpl 0 db 0 s 0 type 2 l 0 g 0 avl 0)
gdt 88f6b/30
idt 0/3ff
cr0 0 cr2 0 cr3 0 cr4 0 cr8 0 efer 0
Abort





I am not sure what's going on but expecting some bug in KVM and will appreciate some help.


As forum don't accept posting with attachments. I can forward the BIOS image to anybody who wants to help.


Thanks
Abhishek

Re: KVM bug

[Sheng Yang]

On Friday 24 July 2009 04:59:51 Saksena, Abhishek wrote:
> Hi
> I am trying to boot a patched version of Boch's BIOS on KVM. It works fine
> with Qemu with -no-kvm option. However I get following with KVM

The first thing come to my mind is your bios lacks some reserved page for VMX. 
See qemu-kvm/kvm/bios/rombios.c for E820 layout in KVM. And is your bios 
bigger than 256KB?

-- 
regards
Yang, Sheng

>
>
> unhandled vm exit: 0x80000021 vcpu_id 0
> rax 0000000000000000 rbx 000000000000133a rcx 0000000000000000 rdx
> 0000000000000008 rsi 0000000000000008 rdi 0000000000000008 rsp
> 00000000000011a4 rbp 00000000000011bc r8  0000000000000000 r9 
> 0000000000000000 r10 0000000000000000 r11 0000000000000000 r12
> 0000000000000000 r13 0000000000000000 r14 0000000000000000 r15
> 0000000000000000 rip 00000000000007ca rflags 00023046
> cs f000 (000f0000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
> ds 88f9 (00088f9b/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
> es 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
> ss c181 (000c1810/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
> fs 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
> gs 0000 (00000000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
> tr 0000 (fffbd000/00002088 p 1 dpl 0 db 0 s 0 type b l 0 g 0 avl 0)
> ldt 0000 (00000000/0000ffff p 1 dpl 0 db 0 s 0 type 2 l 0 g 0 avl 0)
> gdt 88f6b/30
> idt 0/3ff
> cr0 0 cr2 0 cr3 0 cr4 0 cr8 0 efer 0
> Abort
>
>
>
>
>
> I am not sure what's going on but expecting some bug in KVM and will
> appreciate some help.
>
>
> As forum don't accept posting with attachments. I can forward the BIOS
> image to anybody who wants to help.
>
>
> Thanks
> Abhishek
>
> --
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Re: KVM bug

[Avi Kivity]

On 07/23/2009 11:59 PM, Saksena, Abhishek wrote:
> Hi
> I am trying to boot a patched version of Boch's BIOS on KVM. It works fine with Qemu with -no-kvm option. However I get following with KVM
>
>
> unhandled vm exit: 0x80000021 vcpu_id 0
> ds 88f9 (00088f9b/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
>    

When running on Intel we emulate real mode using vm86 mode.  This mode 
requires ds.base == ds.selector << 4, which isn't the case here.  You 
can modify the code to satisfy this requirement, or you can try the 
emulate_invalid_guest_state=1 module parameter (which will likely fail 
since it is not completely implemented).

-- 
error compiling committee.c: too many arguments to function