Re: [Qemu-devel] Running KVM guest on X86

[Bhushan Bharat-R65777]

> -----Original Message-----
> From: Stuart Yoder [mailto:address@hidden
> Sent: Thursday, August 09, 2012 8:28 PM
> To: Bhushan Bharat-R65777
> Cc: Alex Williamson; address@hidden; Avi Kivity
> Subject: Re: [Qemu-devel] Running KVM guest on X86
> 
> On Tue, Aug 7, 2012 at 1:30 AM, Bhushan Bharat-R65777 <address@hidden>
> wrote:
> >
> >
> >> -----Original Message-----
> >> From: Alex Williamson [mailto:address@hidden
> >> Sent: Monday, August 06, 2012 9:27 PM
> >> To: Bhushan Bharat-R65777
> >> Cc: address@hidden; Avi Kivity
> >> Subject: Re: Running KVM guest on X86
> >>
> >> On Mon, 2012-08-06 at 15:40 +0000, Bhushan Bharat-R65777 wrote:
> >> > Hi Avi/All,
> >> >
> >> > I am facing issue to boot KVM guest on x86 (I used to work on
> >> > PowerPC platform
> >> and do not have enough knowledge of x86). I am working on making VFIO
> >> working on PowerPC Booke, So I have cloned Alex Williamsons git
> >> repository, compiled kernel for x86 on fedora with virtualization
> >> configuration (selected all kernel config options for same). Run
> >> below command to boot Guest (I have not provided vfio device yet):
> >> >
> >> > "qemu-system-x86_64 -enable-kvm -m 1024 -nographic -kernel
> >> arch/x86_64/boot/bzImage -initrd /boot/initramfs-3.5.0-rc4+.img
> >> -serial tcp::4444,server,telnet"
> >> >
> >> > After the I can see qemu command line (able to run various commands
> >> > like "info
> >> registers" etc), while guest does not boot (not even the first print 
> >> comes).
> >> >
> >> > Can anyone help in what I am missing or doing wrong?
> >>
> >> x86 doesn't use the serial port for console by default, so you're
> >> making things quite a bit more difficult that way.  Typically you'll
> >> want to provide a disk image (the -hda option is the easiest way to
> >> do this), a display (-vga std -vnc :0 is again easiest), and probably
> >> something to install from (-cdrom <image.iso>).  You can also add a
> >> -boot d to get it to choose the cdrom the first time for install.
> >> Thanks,
> >
> > Thanks Avi and Alex, I can see the KVM guest boot prints by adding -append
> "console=ttyS0"
> 
> Note, once you get to user space you will need a getty specified in
> inittab in order to get a login on your serial port.   Something like:
> 
>    T0:23:respawn:/sbin/getty -L ttyS0

1)
I tried booting with prebuilt qcow2 then it works for me:
qemu-system-x86_64  -enable-kvm  -nographic  -device sga  -m 1024 -hda 
debian_squeeze_amd64_standard.qcow2

Does anyone help on how I can add my kernel to qcow2? Or create a proper qcow2?

2)
Also I tried as mentioned in section "3.9 Direct Linux Boot": 
http://qemu.weilnetz.de/qemu-doc.html#disk_005fimages : 

qemu-kvm  -enable-kvm  -nographic -kernel /boot/vmlinuz-3.5.0+ -hda 
/boot/initramfs-3.5.0+.img  -append "console=ttyS0 root=/dev/sda" -m 1024 

I get below error :
[    1.299225] No filesystem could mount root, tried:  ext3 ext2 ext4 iso9660
[    1.303232] Kernel panic - not syncing: VFS: Unable to mount root fs on 
unknown-block(8,0)
[    1.307683] Pid: 1, comm: swapper/0 Not tainted 3.3.5-2.fc16.x86_64 #1
[    1.311201] Call Trace:
[    1.312548]  [<ffffffff815eac62>] panic+0xba/0x1cd
[    1.315160]  [<ffffffff81cf1075>] mount_block_root+0x258/0x283
[    1.318275]  [<ffffffff81cf10f3>] mount_root+0x53/0x57
[    1.321047]  [<ffffffff81cf1234>] prepare_namespace+0x13d/0x176
[    1.324206]  [<ffffffff81cf0d59>] kernel_init+0x156/0x15b
[    1.327114]  [<ffffffff81089587>] ? schedule_tail+0x27/0xb0
[    1.330102]  [<ffffffff815fd6a4>] kernel_thread_helper+0x4/0x10
[    1.333413]  [<ffffffff81cf0c03>] ? start_kernel+0x3c5/0x3c5
[    1.336446]  [<ffffffff815fd6a0>] ? gs_change+0x13/0x13

Thanks
-Bharat