[Libguestfs] hang after seabios

[Zetan Drableg]

Hi Richard thanks for the info.
I took the strace approach and ran into this looping over and over again.
Is it failing to get time?

timer_gettime(0x8, {it_interval={0, 0}, it_value={0, 0}}) = 0
timer_settime(0x8, 0, {it_interval={0, 0}, it_value={0, 250000}}, NULL) = 0
timer_gettime(0x8, {it_interval={0, 0}, it_value={0, 204443}}) = 0
select(16, [0 6 9 13 15], [], [], {1, 0}) = 2 (in [6 13], left {0, 999998})
read(13, "\1\0\0\0\0\0\0\0", 4096)      = 8
read(13, 0x7fffa2ed3f70, 4096)          = -1 EAGAIN (Resource
temporarily unavailable)
read(6, "\0", 512)                      = 1
read(6, 0x7fffa2ed4d70, 512)            = -1 EAGAIN (Resource
temporarily unavailable)
select(16, [0 6 9 13 15], [], [], {1, 0}) = 1 (in [15], left {0, 999998})
read(15, "\16\0\0\0\0\0\0\0\376\377\377\377\0\0\0\0\0\0\0\0\0\0\0\0\10\0\0\0\0\0\0\0"...,
128) = 128
rt_sigaction(SIGALRM, NULL, {0x7f6d8b8d17d0, ~[KILL STOP RTMIN RT_1],
SA_RESTORER, 0x7f6d8b211710}, 8) = 0
write(7, "\0", 1)                       = 1
write(14, "\1\0\0\0\0\0\0\0", 8)        = 8
read(15, 0x7fffa2ed4ee0, 128)           = -1 EAGAIN (Resource
temporarily unavailable)
timer_gettime(0x8, {it_interval={0, 0}, it_value={0, 0}}) = 0
timer_settime(0x8, 0, {it_interval={0, 0}, it_value={0, 988758000}}, NULL) = 0
select(16, [0 6 9 13 15], [], [], {1, 0}) = 2 (in [6 13], left {0, 999998})
read(13, "\1\0\0\0\0\0\0\0", 4096)      = 8
read(13, 0x7fffa2ed3f70, 4096)          = -1 EAGAIN (Resource
temporarily unavailable)
read(6, "\0", 512)                      = 1
read(6, 0x7fffa2ed4d70, 512)            = -1 EAGAIN (Resource
temporarily unavailable)

It looks a lot like the bug you filed here.
https://bugzilla.redhat.com/show_bug.cgi?id=553689

There are quite a few hits on this trace but nothing real specific.

-Zetan



On Thu, Jul 31, 2014 at 4:31 AM, Richard W.M. Jones <rjones at redhat.com> wrote:
> On Wed, Jul 30, 2014 at 03:58:43PM -0700, Zetan Drableg wrote:
>>    [00183ms] /usr/libexec/qemu-kvm \
>>        -global virtio-blk-pci.scsi=off \
>>        -nodefconfig \
>>        -nodefaults \
>>        -nographic \
>>        -machine accel=kvm:tcg \
>>        -cpu host,+kvmclock \
>>        -m 500 \
>>        -no-reboot \
>>        -kernel /var/tmp/.guestfs-0/kernel.47903 \
>>        -initrd /var/tmp/.guestfs-0/initrd.47903 \
>>        -device virtio-scsi-pci,id=scsi \
>>        -drive file=/tmp/libguestfs-test-tool-sda-Iakpwe,cache=none,format
>>    =raw,id=hd0,if=none \
>>        -device scsi-hd,drive=hd0 \
>>        -drive file=/var/tmp/.guestfs-0/root.47903,snapshot=on,id=appliance,
>>    if=none,cache=unsafe \
>>        -device scsi-hd,drive=appliance \
>>        -device virtio-serial \
>>        -serial stdio \
>>        -device sga \
>>        -chardev socket,path=/tmp/libguestfspx9994/guestfsd.sock,id=channel0
>>    \
>>        -device virtserialport,chardev=channel0,name=org.libguestfs.channel.0
>>    \
>>        -append 'panic=1 console=ttyS0 udevtimeout=600 no_timer_check
>>    acpi=off printk.time=1 cgroup_disable=memory root=/dev/sdb selinux=0
>>    guestfs_verbose=1 TERM=xterm edd=off'
>>    \x1b[1;256r\x1b[256;256H\x1b[6n
>>    Google, Inc.
>>    Serial Graphics Adapter 10/14/11
>>    SGABIOS $Id: sgabios.S 8 2010-04-22 00:03:40Z nlaredo $ (mockbuild@
>>    ca-build44.us.oracle.com) Fri Oct 14 20:04:36 UTC 2011
>>    Term: 80x24
>>    4 0
>>    SeaBIOS (version seabios-0.6.1.2-28.el6)
>>    \x1b[2J
>>
>> At this point it hangs forever.
>
> These hangs can be tricky to diagnose.
>
> There are a couple of things you can do however:
>
> (1) strace qemu to find out what it is doing, or:
>
> (2) [harder, but much more informative] gdb into the guest to find out
> where the guest hangs, or:
>
> (3) Take the command line above, and cut it down to try to isolate the
> problematic options.  I would concentrate on the following options as
> being most likely to cause trouble:
>
>  -cpu
>  -machine
>  -kernel
>  -device sga (remove it)
>
> For (1) and (2) you can use a qemu wrapper to modify the qemu command
> that the test tool runs.
>
> See also:
>
> http://libguestfs.org/guestfs.3.html#qemu-wrappers
>
> http://rwmj.wordpress.com/2011/10/12/tip-debugging-the-early-boot-process-with-qemu-and-gdb/#content
>
> Rich.
>
> --
> Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
> Read my programming and virtualization blog: http://rwmj.wordpress.com
> virt-builder quickly builds VMs from scratch
> http://libguestfs.org/virt-builder.1.html