[Libguestfs] [Resolved] Re: Debugging nested KVM guest (L2) booting with libguestfs/gdb

[Kashyap Chamarthy]

On Thu, Feb 13, 2014 at 09:52:15AM +0000, Richard W.M. Jones wrote:
> On Thu, Feb 13, 2014 at 12:08:37AM +0530, Kashyap Chamarthy wrote:
> > The 'qemu-kvm' command-line just hung at:
> > 
> >     $ ./run libguestfs-test-tool
> >     [. . .]
> >         -chardev socket,path=/home/tuser1/src/libguestfs/tmp/libguestfspCGc1F/guestfsd.sock,id=channel0 \
> >     -device virtserialport,chardev=channel0,name=org.libguestfs.channel.0 \
> >     -append 'panic=1 console=ttyS0 udevtimeout=600 no_timer_check lpj=2294686 acpi=off printk.time=1 cgroup_disable=memory root=/dev/sdb selinux=0 guestfs_verbose=1 TERM=screen'
> 
> It's supposed to "hang" if you add the -S -s arguments.

Yep! (That indicates how often I use GDB.)

On a more closer look:

    [. . .]
    checking modpath /lib/modules/3.14.0-0.rc2.git0.1.fc21.x86_64 is a directory
    picked kernel vmlinuz-3.14.0-0.rc2.git0.1.fc21.x86_64
    supermin helper [00000ms] finished creating kernel
    [. . .]
    libguestfs: warning: qemu debugging is enabled, connect gdb to tcp::1234 to begin
    [. . .]

> 
> It is waiting for you to connect gdb to qemu.

Yes:


    (gdb) symbol-file /usr/lib/debug/lib/modules/3.14.0-0.rc2.git4.1.fc21.x86_64/vmlinux
    Reading symbols from /usr/lib/debug/lib/modules/3.14.0-0.rc2.git4.1.fc21.x86_64/vmlinux...done.
    (gdb) target remote tcp::1234
    Remote debugging using tcp::1234
    0x0000fff0 in cpu_lock_stats ()
    (gdb) cont
    Continuing.

As I write this, the applinace test (ran on L1) is successful. 
`qemu-sanity-check` doesn't succeed, still investigating.

Thanks.

-- 
/kashyap