On (Thu) 16 Jun 2011 [13:38:49], Luiz Capitulino wrote:
> If I start qemu with:
>
> # qemu -hda disks/test.img -enable-kvm -m 1G -snapshot \
> -device virtio-serial \
> -chardev socket,host=localhost,port=1234,server,nowait,id=foo \
> -device virtserialport,chardev=foo,name=org.qemu.guest_agent
>
> I get a segfault when booting a Fedora 14 guest. The backtrace says:
>
> Program terminated with signal 11, Segmentation fault.
> #0 0x0000000000420850 in handle_control_message (vser=0x3732bd0,
> buf=0x2c173e0, len=8) at
> /home/lcapitulino/src/qmp-unstable/hw/virtio-serial-bus.c:335
> 335 info = DO_UPCAST(VirtIOSerialPortInfo, qdev, port->dev.info);
Strange, I've not seen it so far in my testing (neither in the daily
test runs of the virtio-serial testsuite).
> I've also bisected this and git points out to commit:
>
> commit a15bb0d6a981de749452a5180fc8084d625671da
> Author: Markus Armbruster <arm...@redhat.com>
> Date: Wed May 25 14:21:13 2011 +0200
>
> virtio-serial: Drop redundant VirtIOSerialPort member info
>
> I think what's happening is that the device is not initialized on a
> VIRTIO_CONSOLE_DEVICE_READY event. Moving the DO_UPCAST() call to
> the other events fixes the problem to me.
>
> Signed-off-by: Luiz Capitulino <lcapitul...@redhat.com>
> ---
> hw/virtio-serial-bus.c | 4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c
> index 9a12104..579f676 100644
> --- a/hw/virtio-serial-bus.c
> +++ b/hw/virtio-serial-bus.c
> @@ -332,8 +332,6 @@ static void handle_control_message(VirtIOSerial *vser,
> void *buf, size_t len)
> if (!port && cpkt.event != VIRTIO_CONSOLE_DEVICE_READY)
> return;
>
> - info = DO_UPCAST(VirtIOSerialPortInfo, qdev, port->dev.info);
> -
Ah - this missed the !port check. It should be possible to do this in
a 'if (port)' block instead of replicating in the individual case
statements.
Thanks for the debugging and patch; please update with the above and
I'll apply it to the virtio-serial tree.
Amit
