VFIO software KVM switch from hell to deal with unreliable mouse attachment

attach-keyboard-mouse-to-guest.sh

#!/bin/bash

set -eu

guest=$1

attached_to_file=~/.cache/keyboard-mouse-attached-to-guest
echo -n -E "$guest" > $attached_to_file

attach-keyboard-mouse-to-host.sh

#!/bin/bash

set -eu

attached_to_file=~/.cache/keyboard-mouse-attached-to-guest
rm -f "$attached_to_file"

mouse=046d:c048
keyboard=0d3d:0001

if virsh --connect qemu:///system list | grep -qP 'windows10 +running$'; then
	guest=windows10
else
	guest=macos
fi

vm-usb-device detach "$guest" $mouse    || true
vm-usb-device detach "$guest" $keyboard || true

set-input-device-settings

set-input-device-settings.sh

#!/bin/bash

xset m 0 0

software_kvm_loop.sh

#!/bin/bash

# Deal with Logitech G9 initialization failure weirdness (caused by display
# input switch & ScpToolkit jank?) and handle the keyboard too while we're at it

mouse=046d:c048
mouse_name="Logitech G9 Laser Mouse"
keyboard=0d3d:0001
keyboard_name="USBPS2"

attached_to_file=~/.cache/keyboard-mouse-attached-to-guest

ensure_running() {
	guest=$1
	if [[ $(virsh --connect qemu:///system list | grep -P -c "$guest +running$") -eq 0 ]]; then
		echo "[$(date)] $guest is no longer running, removing $attached_to_file"
		rm -f "$attached_to_file"
		return 0
	else
		return 1
	fi
}

while true; do
	if [[ -f "$attached_to_file" ]]; then
		guest=$(<$attached_to_file)
		if xinput list | fgrep -m 1 -q "$keyboard_name"; then
			if ensure_running "$guest"; then
				continue
			fi
			vm-usb-device detach "$guest" $keyboard 2> /dev/null && echo "[$(date)] detached keyboard from $guest" || true
			vm-usb-device attach "$guest" $keyboard && echo "[$(date)] keyboard attached to $guest" || echo "[$(date)] failed to attach keyboard to $guest"
		fi
		# Logitech G9 has two entries in `xinput list` when attached at host; if there are 0 or 1, assume it's on guest
		if [[ $(xinput list | fgrep -c "$mouse_name") -eq 2 ]]; then
			if ensure_running "$guest"; then
				continue
			fi
			# Wait for monitor input switch to calm down because the mouse is sensitive to failing initialization
			# TODO: maybe use a better mechanism e.g. have guest request the mouse when it's sufficiently calm
			sleep 2.5
			vm-usb-device detach "$guest" $mouse 2> /dev/null && echo "[$(date)] detached mouse from $guest" || true
			vm-usb-device attach "$guest" $mouse && echo "[$(date)] mouse attached to $guest" || echo "[$(date)] failed to attach mouse to $guest"
		fi
	fi
	sleep 0.25
done

vm-usb-device.sh

#!/bin/bash

set -eu

# Usage:
# vm-usb-device attach windows10 046d:c048
# vm-usb-device detach windows10 046d:c048
# (use lsusb to get vendor:product id)

action=$1
vmname=$2
device=(${3//:/ })
xml_name=/tmp/device-${device[0]}:${device[1]}.xml

echo "\
<hostdev mode='subsystem' type='usb'>
	<source>
		<vendor  id='0x${device[0]}'/>
		<product id='0x${device[1]}'/>
	</source>
</hostdev>" > $xml_name

virsh --quiet --connect qemu:///system "$action"-device "$vmname" "$xml_name"