docs/multiseat.txt: use autoseat

When using the autoseat feature of systemd/logind we'll only need
a single udev rule for the pci bridge, which simplifies the guest
setup a bit.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Gerd Hoffmann 2014-05-26 09:52:48 +02:00
parent 2deb4acc7c
commit 3503206a90

View file

@ -46,29 +46,37 @@ You need a pretty recent linux guest. systemd with loginctl. kernel
fully updated for the new kernel though, i.e. the live iso doesn't cut
it.
Now we'll have to configure the guest. Boot and login. By default
all devices belong to seat0. You can use "loginctl seat-status seat0"
to list them all (and to get the sysfs paths for cut+paste). Now
we'll go assign all pci devices connected the pci bridge in slot 12 to
a new head:
Now we'll have to configure the guest. Boot and login. "lspci -vt"
should list the pci bridge with the display adapter and usb controller:
loginctl attach seat-qemu \
/sys/devices/pci0000:00/0000:00:12.0/0000:01:02.0/drm/card1
loginctl attach seat-qemu \
/sys/devices/pci0000:00/0000:00:12.0/0000:01:02.0/graphics/fb1
loginctl attach seat-qemu \
/sys/devices/pci0000:00/0000:00:12.0/0000:01:0f.0/usb2
[root@fedora ~]# lspci -vt
-[0000:00]-+-00.0 Intel Corporation 440FX - 82441FX PMC [Natoma]
[ ... ]
\-12.0-[01]--+-02.0 Device 1234:1111
\-0f.0 NEC Corporation USB 3.0 Host Controller
Use "loginctl seat-status seat-qemu" to check the result. It isn't
needed to assign the usb devices to the head individually, assigning a
usb (root) hub will automatically assign all usb devices connected to
it too.
Good. Now lets tell the system that the pci bridge and all devices
below it belong to a separate seat by dropping a file into
/etc/udev/rules.d:
BTW: loginctl writes udev rules to /etc/udev/rules.d to make these
device assignments permanent, so you need to do this only once.
[root@fedora ~]# cat /etc/udev/rules.d/70-qemu-autoseat.rules
SUBSYSTEMS=="pci", DEVPATH=="*/0000:00:12.0", TAG+="seat", ENV{ID_AUTOSEAT}="1"
Now simply restart gdm (rebooting will do too), and a login screen
should show up on the second head.
Reboot. System should come up with two seats. With loginctl you can
check the configuration:
[root@fedora ~]# loginctl list-seats
SEAT
seat0
seat-pci-pci-0000_00_12_0
2 seats listed.
You can use "loginctl seat-status seat-pci-pci-0000_00_12_0" to list
the devices attached to the seat.
Background info is here:
http://www.freedesktop.org/wiki/Software/systemd/multiseat/
Enjoy!