[vfio-users] Looking for recommendations for screen-switching

[Daniel Oram]

On 20/03/17 10:38, Patrick O'Callaghan wrote:
>
> On 20 March 2017 at 07:36, Rokas Kupstys <rokups at zoho.com
> <mailto:rokups at zoho.com>> wrote:
>
>     You might try installing ddccontrol and trying. Maybe they simply
>     did not bother enough to list it in docs. Maybe monitor is based on
>     same hardware as other more high-end monitors are and functionality
>     is in there even if vendor does not say its supported.
>
>
> I did try that but it tells me my monitor is not in the database. I also
> note that the most recent version of ddccontrol is from 2006, which
> doesn't inspire much confidence.
>
> poc
>
>
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Try ddcutil

http://www.ddcutil.com/

Much more comprehensive. Using something like:

sudo modprobe i2c-dev
sudo ddcutil capabilities

To list any standard recognised capabilities for your monitor (it is up 
to date). You may have it but vpd may not be standardised and ddcutil 
gives you the tools to work that out if you have the patience.

I bought a KVM in the end ... and it's so awful I only use it as an HDMI 
switch and use the input-linux framework in qemu to switch the 
keyboard/mouse. USB switches do work, but only good ones will work with 
every device and udev can make a mess of rapidly switching devices in 
and out, especially if they have some sort of custom software as the 
device won't come back to the same location as it left. In Windows a 
mess is normal but it will probably get worse. HDMI switches may have 
limitations on max resolution, bandwidth and types of data so be careful 
when buying.

The input-linux framework can have the odd problem with missed key ups 
but they are all easily surmountable by attaching a USB or virtio 
keyboard device to the VM so are far preferable to hardware related 
limitations or problems of the switch and constant device plugging in 
the VMs. After all, that is one of the major motivations for using a VM.