Re: [Qemu-devel] [PATCH v4 2/4] char: convert from GIOChannel to QIOChannel

[Laurent Vivier]

On 18/03/2016 17:56, Daniel P. Berrange wrote:
> On Fri, Mar 18, 2016 at 05:43:42PM +0100, Laurent Vivier wrote:
>> Hi,
>>
>> testing something else (migration...) I've discovered (by bisecting)
>> that this patch can allow to lock the machine. I'm using the pseries
>> machine, but I think it should happen with PC too.
>>
>> I start a machine with:
>>
>>      ...
>>      -device virtio-serial-pci,id=serial0 \
>>      -chardev socket,id=channel0,path=/tmp/serial_socket,server,nowait \
>>      -device virtserialport,bus=serial0.0,nr=1,chardev=channel0
>>
>> and I open the unix socket /tmp/serial_socket without reading it:
>>
>> $ python
>> import socket
>> sock = socket.socket(socket.AF_UNIX)
>> sock.connect("/tmp/serial_socket_1")
>>
>> Then in the guest:
>>
>> cat /dev/zero > /dev/vport1p1
>>
>> -> at this point, the machine hangs until we read data in unix socket
>> (we can't interact with monitor, we can't ping the machine...)
> 
> Pretty sure that'll be the same issue Andrew reported here
> 
> https://lists.gnu.org/archive/html/qemu-devel/2016-03/msg02843.html
> 
> can you see if his suggested addition works for you too

Yes, it works :)

Thanks,
Laurent