Scrolling in Linux/Ubuntu is either too slow or too fast

[BryanSmith]

I am using a Macbook Pro M1 2021, and only using the built-in trackpad, to run a Linux guest.
I understand that Linux/Ubuntu has moved towards using libinput, and that this means that trackpad scroll speed is not customizable.
Further, the virtual mouse provided by Parallels is not a trackpad, and doesn't have configurable parameters.
It is possible to adjust scroll speed in Firefox. But not for other applications, such as VSCode, or Nautilus.
In general, the scrolling experience is barely acceptable, to the point where I would happily switch to VMware if their solution was better, but it's not.
Can you please implement trackpad support in Linux/Ubuntu? It works well/smoothly in my Windows guest, equivalent to the scrolling experience on the host.
This would provide amazing value for the Mac-Parallels-Linux ecosystem, and keep me as a customer for many years.

--
I have tried:
- libinput customization
- smooth scrolling in the configuration file
- "optimize for games". Note that I use side-swiping to change between host and guest (and this works well with Windows), so "optimize for games" is not even an option for me, because it grabs all gestures.

 

[Gamesurgeon]

For VM software that costs $100 per year, I'd at least expect the mouse to work. Can we fix this? No matter what I try, my scroll wheel only registers through evtest every N clicks on my MX Master 3. Works fine on VMWare Fusion Pro...which is free.

 

[Gamesurgeon]

I've completely stopped using Parallels and just moved over to UTM. It works great. VMWare supports Linux better than Parallels, too. There's no reason for anyone to pay $120 per year to use an old kernel, buggy closed-source tools, and broken drivers when there are OSS or free solutions.

 

[BobTheDog]

Good to see nothing has changed in version V26, I'm wondering how many versions I have gone through with this being awful!

If I connect my Apple trackpad by usb to the VM everything works absolutely brilliantly, I can see in the settings that Ubuntu is seeing a trackpad, everything is smooth as anything.

If I go through the VM then Ubuntu sees it as a mouse, the parallels stuff is actually sending button presses for scrolling up, down, left and right which is why we see this awful scrolling.

Anyone at parallels who cares about this, just run xev in a terminal to test it.

Here is what I get scrolling up and down:

ButtonPress event, serial 37, synthetic NO, window 0xc00001,
root 0x4aa, subw 0x0, time 334627, (172,144), root380,372),
state 0x0, button 4, same_screen YES

ButtonRelease event, serial 37, synthetic NO, window 0xc00001,
root 0x4aa, subw 0x0, time 334627, (172,144), root380,372),
state 0x800, button 4, same_screen YES

ButtonPress event, serial 37, synthetic NO, window 0xc00001,
root 0x4aa, subw 0x0, time 336627, (172,144), root380,372),
state 0x0, button 5, same_screen YES

ButtonRelease event, serial 37, synthetic NO, window 0xc00001,
root 0x4aa, subw 0x0, time 336627, (172,144), root380,372),
state 0x1000, button 5, same_screen YES