[libvirt] [PATCH RFC 2/4] qemu_agent: ignore requests echoed back by guest

[Joao Martins]

On 03/02/2017 06:16 PM, Daniel P. Berrange wrote:
> On Thu, Mar 02, 2017 at 11:10:10AM -0700, Jim Fehlig wrote:
>> On 02/08/2017 09:44 AM, Joao Martins wrote:
>>> Signed-off-by: Joao Martins <joao.m.martins at oracle.com>
>>
>> Since it wasn't needed before, I think it is helpful for the commit message
>> to describe why the change is needed now.
> 
> I'm open to being convinced otherwise, but I'd say that if the guest
> is echo'ing back commands the host sends, then the guest is broken
> and we shouldn't workaround that in libvirt. Or perhaps something
> about the hypervisor data channel over which the guest agent is
> running is running.
>
> Seeing data echo'd back suggests use of a PTY which has not been
> put into raw mode, or something like that.

OK, Thanks for the pointers.

This is one of the biggest reasons this is an RFC, as I haven't investigated
this properly yet. My gut feeling was that this could be on the device model
side (i.e. qemu) or even xenconsole handling side - and this was happening on
both socket and pty channel types. Anyhow, I can't make the argument/case for
inclusion of this patch yet, but being a one-liner I thought of including it for
purposes of a working RFC/prototype.

Joao