[systemd-devel] Two questions about logind and seats

[Lennart Poettering]

On Sa, 29.07.17 00:34, nerdopolis (bluescreen_avenger at verizon.net) wrote:

> Hi
> 
> I hope this is the right place to ask this. I have two questions about logind
> and seats. 
> 
> First, when I attach a 2nd graphics card to seat1, it seems CanMultisession is
> set to 0. Is there a way to change that? or is that only supported on seat0, 
> that supports the TTYs?

Yes, this is only supported where VTs are supported, and that is only seat0.

> Second, with systemd-run, and maybe a custom '-p PAMName=somepamfile' (if that
> is required), is there a way to spawn a process on seat1 if it exits?
> For seat0 sessions, they for instance can be started by specifying

> -pTTYPath=/dev/ttyX -pStandardOutput=tty -pStandardError=tty
> --pStandardInput=tty

Other seats don't have VTs, hence you cannot run anything on any such
VTs...

To make use of these other seats you need some kind of terminal
emulator that knows how to draw to DRM directly, and then you can
connect your service to that.

> to systemd-run, which I know only seat0 supports ttys...
> I try to do weston --seat=seat1 and it says that seat1 does not match the 
> session-seat.
> Is there a way to start a process with under a specific session-seat?

Well, I don't know weston that well, but presumably you are invoking
it from a session that is attached to seat0, and it doesn't like that
you try to run it on a different seat then, which makes a ton of sense
to complain about. Contact the weston folks for help on this.

Lennart

-- 
Lennart Poettering, Red Hat