On Mon, Aug 5, 2019 at 11:14 PM Gerd Hoffmann <kra...@redhat.com> wrote: > > On Mon, Aug 05, 2019 at 12:50:00PM -0700, Micah Morton wrote: > > On Thu, Aug 1, 2019 at 10:36 PM Gerd Hoffmann <kra...@redhat.com> wrote: > > > > > > Hi, > > > > > > > From my perspective, as a low-speed device where we don't really need > > > > the benefits of an IOMMU, I'd be more inclined to look at why it > > > > doesn't work with evdev. We already have a tablet device in QEMU, > > > > what's it take to connect that to evdev? Cc'ing Gerd as maybe he's > > > > already though about touchpad support. Thanks, > > > > > > It's not clear why the touchpad doesn't work. Possibly using libinput > > > helps, https://git.kraxel.org/cgit/qemu/log/?h=sirius/display-drm has > > > some code. Wiring up to input-linux isn't done yet though, only the > > > drm ui uses libinput support so far. > > > > To be clear are you saying that its a known issue that the touchpad > > doesn't work in VM guest with QEMU and evdev? > > There are other reports of touchpad problems. I don't know whenever > that is a general problem or specific to some devices. > > libinput knows quirks for lots of input devices. When passing through > the evdev to the guest as virtio device libinput can't see the device > identity and thus can't apply quirks. Which might be the reason the > touchpad doesn't work. Using libinput on the host side might fix this. > > cheers, > Gerd >
I was able to get physical passthrough of the touchpad working in the VM guest by forwarding the IRQ to the guest using the kvm/qemu/vfio framework. So basically I wrote extensions to kvm/qemu/vfio to allow for forwarding arbitrary IRQs to the guest (the IRQ doesn't have to be associated with any vfio-pci or vfio-platform device). I could clean up the patches and upstream them (or think about it) if you folks think anyone else might want to use this functionality? Then again as Alex said before you still need to communicate to the VM which IRQ to use for this device (in my case I did this by modifying ACPI stuff in SeaBIOS, not sure how it could be incorporated into vfio). _______________________________________________ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
