Hi,
resending this, seems you did a typo when CCing qemu-devel and I've just
blindly replied-all and got a bounce, sorry for doubled mail, I keep you
both in recipients so we don't have multiple threads later.
Gh.
Jiri 'Ghormoon' Novak wrote:
Hi
Gerd Hoffmann wrote:
Hi,
[ Cc'ing qemu-devel + alex ]
when discussing my attempts at passthrough of ps2 input, I've been
pointed towards your work on virtio-input.
I've got a question:
Did you think about attaching those to standard qemu input, so even
hosts without virtio drivers can use them? It would be great help if
keyboard could be used like that.
You mean grab events from /dev/input/event$nr and feed them into the
qemu input system, so they show up on whatever emulated input device the
guest happens to have? Should be doable for keyboard and mouse. Not so
easy for tablet/touchscreen.
Might be useful for people doing vga pass-through using vfio too,
keyboard/mouse input is a constant source of trouble there.
Exactly that's my use-case. I'm doing VGA-passthrough of my only
(laptop) VGA and passing in the laptop keyboard too (they're still ps2
keyboards technically, not usb, that would be fairly easy).
I'm curretly using a hack that I got here:
http://lists.xen.org/archives/html/xen-devel/2010-03/msg01292.html and
heavily modified it for qemu 2. But I've done it very wrong back then
- hacking pckbd.c to give me the pointer to showel in input from
/dev/tty0.
I've been discussing this on #qemu and got directed to look at
ui/curses.c, which is likely closest to what I need to do, but only
for input and more lowlevel. They also pointed me to your work, so
I've asked about that, if I can use it.
Seems I'll try to start from the curses.c then, if that's better way
(my knowledge of qemu codebase is zero and I'm not a good developer
either, but I may try in my free time since I need this and I'd like
to see it upstream - there are more people trying vga passthrough who
possibly need this :)) At least keyboard, mouse is nice to have, but
that can be done with the virtio-input, it's not crucial eg. during
installation where you may not have those drivers.
Is there any technical reason it can't/shouldn't be done with your
devices?
That wouldn't be related to virtio-input at all, and also probably
wouldn't be able to share much code with virtio-input-host as qemu would
have to interpret the linux input layer events then instead of passing
them through to the guest without looking at them much.
also, do you have any public testing VMs, that are known to work with
synaptics touchpad? I'm trying out the virtio devices, I've managed to
get trackpoint working, but touchpad kills the guest X. I'd like to
make
sure the problem is guest-side. If you don't have one, I'll try to make
more experiments myself to see where the problem is.
I'd suspect X in the guest is surprised to find the touchpad attached
via virtio instead of ps/2, possibly because it tries to configure the
touchpad and doesn't find the knobs needed to do so ...
I was just wondering if you don't have a bunch of testing VMs that
you've already used for this to quickly rule out one side (host or
guest). I've tested it on debian only so far (jessie-backports
kernel), I may install few more to see if it's not some unrelated bug
(it crashes on floating point exception in synaptics driver).
cheers,
Gerd
Thanks for the reply,
Gh.
