Re: error: building kvm for powerpc using cross compiler on x86

[Dushyant Bansal <cs5070214@cse.iitd.ac.in>]

On Thursday 13 January 2011 04:23 AM, Alexander Graf wrote:
> On 12.01.2011, at 21:51, Dushyant Bansal<cs5070214@cse.iitd.ac.in>  wrote:
>
>    
>>      
>>>>> $ cp arch/powerpc/configs/pmac32_defconfig .config
>>>>> $ make menuconfig ARCH=powerpc
>>>>>
>>>>> seems to work. I'm not sure what default config is taken by default, but apparently one of the KVM constraints isn't fulfilled. Since you want to build a kernel for a pmac32 anyways, just take that config as the basis or use the one from a VM you already have working :).
>>>>>
>>>>>
>>>>> Alex
>>>>>
>>>>>
>>>>>            
>>>> I tried to build kernel image for powerpc-750
>>>> user@user:~/project/kvm$ cp arch/powerpc/configs/pmac32_defconfig .config
>>>> user@user:~/project/kvm$ make ARCH=powerpc menuconfig
>>>>
>>>> [I selected "KVM support for PowerPC book3s_32 processors" under virtualization menu. I have attached the final .config file]
>>>>
>>>> user@user:~/project/kvm$ make ARCH=powerpc CROSS_COMPILE=powerpc-750-linux-gnu-
>>>> [I get this error]
>>>>    CHK     include/linux/version.h
>>>>    CHK     include/generated/utsrelease.h
>>>>    CALL    scripts/checksyscalls.sh
>>>>    CHK     include/generated/compile.h
>>>>    CALL    arch/powerpc/kernel/systbl_chk.sh
>>>>    CALL    arch/powerpc/kernel/prom_init_check.sh
>>>>    AS      arch/powerpc/kvm/fpu.o
>>>> arch/powerpc/kvm/fpu.S: Assembler messages:
>>>> arch/powerpc/kvm/fpu.S:244: Error: Unrecognized opcode: `frsqrtes.'
>>>> arch/powerpc/kvm/fpu.S:250: Error: Unrecognized opcode: `fre.'
>>>> arch/powerpc/kvm/fpu.S:259: Error: Unrecognized opcode: `fcpsgn.'
>>>> make[1]: *** [arch/powerpc/kvm/fpu.o] Error 1
>>>> make: *** [arch/powerpc/kvm] Error 2
>>>>
>>>>          
>>> This means that your assembler doesn't understand some of the floating point instructions in the paired single emulation code. Since you don't need that code anyways, just comment them out.
>>>
>>>
>>>        
>> Thanks a lot, Alex. After debugging some more errors, I was finally able to compile it.
>>
>> user@user:~/kvm$ make distclean
>> user@user:~/kvm$ cp arch/powerpc/configs/pmac32_defconfig .config
>> user@user:~/kvm$ make ARCH=powerpc menuconfig
>> [I selected "KVM support for PowerPC book3s_32 processors" under virtualization menu.]
>> user@user:~/kvm$ make ARCH=powerpc CROSS_COMPILE=powerpc-750-linux-gnu-
>> user@user:~/kvm$ make ARCH=powerpc CROSS_COMPILE=powerpc-750-linux-gnu- modules
>>
>> Then, I mounted the qemu-system-ppc image "debian_lenny_powerpc.raw".
>>
>> user@user:/$  losetup /dev/loop0 debian_lenny_powerpc.raw
>> user@user:/$  kpartx -a /dev/loop0
>> user@user:/$  mount /dev/mapper/loop0p3 /mnt/image2
>> user@user:/$  mount /dev/mapper/loop0p2 /mnt/image2/boot/
>>
>> user@user:~/kvm$ sudo make ARCH=powerpc CROSS_COMPILE=powerpc-750-linux-gnu- INSTALL_NOD_PATH="/mnt/image2" modules_install
>>
>> [Replaced /boot/vmlinux with the generated vmlinux]
>> user@user:~/kvm$ cp vmlinux /mnt/image2/boot/vmlinux
>>
>> And, on booting that image [debian_lenny_powerpc.raw], I can see the new kernel image.
>>
>> # uname -r
>> 2.6.37-rc6+
>> But still, I cannot find the kvm module. File kvm.ko is not present inside "lib/modules/2.6.37-rc6+/"
>>
>> # modprobe kvm
>> FATAL: Module kvm not found.
>>
>> Am I missing something? How do I build kvm module ?
>>      
> Did you select it as * or M? If it's *, there is no module - everything is in the kernel and (with proper udev) you should just get /dev/kvm.
>
> Alex
>
>    
Yes, I am using * for selection. Thanks for the info.

Dushyant