booting kernel with kvm

Paul Bolle pebolle at tiscali.nl
Wed Oct 15 06:17:47 EDT 2014


On Wed, 2014-10-15 at 15:01 +0530, harisha ja wrote:
> I have windows 7 system and I have installed ubuntu using vmware. I
> have installed KVM on ubuntu and I am trying to boot the kernal image
> with KVM.

Does vmware emulate the KVM related chip functionality (ie, "VT" for an
x86 Intel CPU or "AMD-V (SVM)" for x86 AMD CPU)?

> But I am not sure what is the problem. I am stuck in this screen. Is
> something I am missing here? 
>
> The approach using kvm to put some logs and to see module
> initialization is wrong?. 
>
> The command I am using 
> kvm  -kernel ./arch/x86/boot/bzImage  -append root=/root/

You call this command in your vmware session of a virtual Ubuntu system,
don't you?

> I see the below message and then the qemu prompt does not boot and
> stops by displaying below traceback.
>
> Could not access KVM kernel module: No such file or directory
> failed to initialize KVM: No such file or directory

Is this the only message, or only the part you thought was interesting?

> QEMU 
> 5.1654731 Stack: 5.1654731 c18ea844 claea9a0 00000000 fffffffa
> d?861efc 00008001 d?8611 a35f91 5.1654731 cl8ddba8 d?861efc d7861efc
> fffffffa 00000000 d7b6e000 cl8dd6 ff3dc0 5.1654731 d7b6e000 6e6b6e75
> 2d6e??61 636f 6c62 2c30286b c1002930 d78611 13c248 5.1654731 
> Call Trace: 
> 5.1654731 l<c1a35f91>1 mount_block_root+Ox158/0x1de 
> 5.1654731 l<c1002930>1 ? do_general_protection+0x40/0x170 
> 5.1654731 l<c113c248>1 ? SyS_mknod+0x28/0x30 
> 5.1654731 l<cla3610a>1 mount_root+Oxf3/Oxfb 
> 5.1654731 l<c1a36235>1 prepare_namespace+0x123/0x167 
> 5.1654731 l<c112cf30>l ? SyS_access+0x20/0x30 
> 5.1654731 l<cla35cf7>1 kernel_init_freeable+Ox1b5/0x1c2 
> 5.1654731 l<c1a35545>1 ? do_early_param+0x74/0x74 
> 5.1654731 l<c174caab>1 kernel_init+Oxb/Oxe0
> 5.1654731 l<c175a041>1 ret_from_kernel_thread+0x21/0x30 
> 5.1654731 l<c174caa0>1 ? rest_init+0x60/0x60
> 5.1654731 Code: 00 00 00 00 31 ff 83 3d 8c a9 ae cl 00 74 05 e8 Oe dO
> 9 c? 44 24 04 a0 a9 ae cl c7 04 24 44 a8 Be cl e8 b6 05 00 00 fb 3116
> <35>1 15 83 75 f0 01 8b 45 f0 ff 15 80 a9 ae cl 01 c6 8d be 5.1654731
> EIP: l<c174f2e9>1 panic+0x165/0x197 SS:ESP 0068:d7861eb8 5.1654731 --I
> end trace a4Obaf277b417d8d 1-- 

This looks like the kind of backtrace one gets when the kernel can't
find its root device. I see something like it every now and then, and it
mostly means that I made a mistake when I configured a machine. It also
means, I think, that the KVM problem you quoted wasn't fatal for this
virtual boot.

Setting the root device might be tricky to get right when booting a
virtualized system. At least, I remember fiddling with it. But your
"root" kernel parameter should be something like:
    root=/dev/sda1

It rather depends on how your Ubuntu system is setup (ie, what the
layout is of the image that vmware uses to boot Ubuntu, apparently).


Paul Bolle




More information about the Kernelnewbies mailing list