From 8977bd111f62035b675d41c432eb8b6bf6b86b0f Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 20 May 2014 09:17:01 +0200 Subject: [PATCH] docs: add multiseat.txt Howto on setting up multiseat for guests. Signed-off-by: Gerd Hoffmann --- docs/multiseat.txt | 76 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 docs/multiseat.txt diff --git a/docs/multiseat.txt b/docs/multiseat.txt new file mode 100644 index 0000000000..a6c71dd74f --- /dev/null +++ b/docs/multiseat.txt @@ -0,0 +1,76 @@ + +multiseat howto (with some multihead coverage) +============================================== + +host side +--------- + +First you must compile qemu with a user interface supporting +multihead/multiseat and input event routing. Right now this list is +pretty short: sdl2. + + ./configure --enable-sdl --with-sdlabi=2.0 + + +Next put together the qemu command line: + +qemu -enable-kvm -usb $memory $disk $whatever \ + -display sdl \ + -vga std \ + -device usb-tablet + +That is it for the first head, which will use the standard vga, the +standard ps/2 keyboard (implicitly there) and the usb-tablet. Now the +additional switches for the second head: + + -device pci-bridge,addr=12.0,chassis_nr=2,id=head.2 \ + -device secondary-vga,bus=head.2,addr=02.0,id=video.2 \ + -device nec-usb-xhci,bus=head.2,addr=0f.0,id=usb.2 \ + -device usb-kbd,bus=usb.2.0,port=1,display=video.2 \ + -device usb-tablet,bus=usb.2.0,port=2,display=video.2 + +This places a pci bridge in slot 12, connects a display adapter and +xhci (usb) controller to the bridge. Then it adds a usb keyboard and +usb mouse, both connected to the xhci and linked to the display. + +The "display=video2" sets up the input routing. Any input coming from +the window which belongs to the video.2 display adapter will be routed +to these input devices. + + +guest side +---------- + +You need a pretty recent linux guest. systemd with loginctl. kernel +3.14+ with CONFIG_DRM_BOCHS enabled. Fedora 20 will do. Must be +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: + +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 + +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. + +BTW: loginctl writes udev rules to /etc/udev/rules.d to make these +device assignments permanent, so you need to do this only once. + +Now simply restart gdm (rebooting will do too), and a login screen +should show up on the second head. + +Enjoy! + +-- +Gerd Hoffmann