Re: confused with invept

[Sheng Yang <yasker@gmail.com>]

On Fri, Jan 30, 2009 at 12:10:18PM -0700, Bill Rieske wrote:
> I get the following extracted from dmesg when essentially modprobing kvm_intel.  Note: distro using kvm 78

Hi Bill

Are you using Core i7 processor? Only it support EPT. What's your host
kernel version? And I think we can try the latest KVM module first.

> This is what I have derived from objdump -M x86_64,intel -Sl vmx.o
> vmx_init is at 0x2ee  + 0x1ec is 4da
> extracted from the objdump 
>  4b5:   f6 05 00 00 00 00 04    test   BYTE PTR ds:0x0,0x4
>  4bc:   74 4d                   je     50b <init_module+0x21d>
>  4be:   48 c7 44 24 20 00 00    mov    QWORD PTR [rsp+32],0x0
>  4c5:   00 00
>  4c7:   48 c7 44 24 28 00 00    mov    QWORD PTR [rsp+40],0x0
>  4ce:   00 00
>  4d0:   48 8d 44 24 20          lea    rax,[rsp+32]
>  4d5:   b9 02 00 00 00          mov    ecx,0x2
>  4da:   66                      data16
>  4db:   0f 38 80                (bad)
>  4de:   08 77 02                or     BYTE PTR [rdi+2],dh
>  4e1:   0f 0b                   ud2a
>  4e3:   eb 26                   jmp    50b <init_module+0x21d>
> 
> which from what I gather is the instruction for INVEPT opcode 660f3880
> from what I can tell from the code I shouldn't invoke this instruction if the bit isn't valid from 
>        ept_sync_global();

Sure. The bit should be filled by setup_vmcs_config() in vmx.c. I hope the
vmx_capability haven't been corrupted...

> from what I gather it's faulting in the __invept or am I totally down the wrong path.
> Any Ideas on whats going on would be helpful or how I should proceed.
> 

Please help to identify your processor, the value of vmx_capability.ept and
try latest KVM.

Thanks.

-- 
regards
Yang, Sheng	|Intel Opensource Technology Center