wireguard patch for threaded NAPI. See https://git.zx2c4.com/wireguard-linux/commit/?id=db9ae3b6b43c79b1ba87eea849fd65efa05b4b2e

install-wireguard-patch.sh

#!/bin/bash
sudo apt-get install build-essential linux-source bc kmod cpio flex libncurses5-dev libelf-dev libssl-dev dwarves bison linux-headers-amd64
tar xavf /usr/src/linux-source-$(uname -r | cut -d. -f1,2).tar.xz
cd linux-source-$(uname -r | cut -d. -f1,2)

# apply patch
wget -O wireguard.patch https://git.zx2c4.com/wireguard-linux/patch/?id=db9ae3b6b43c79b1ba87eea849fd65efa05b4b2e
patch -p1 < wireguard.patch
#rm wireguard.patch

cat /boot/config-$(uname -r) > .config
make menuconfig
# search for WireGuard (using /), go there and enable it as a module (M) in menuconfig

make modules_prepare
make prepare
#make modules M=drivers/net/wireguard
# the below one helped with an issue
make -C /lib/modules/$(uname -r)/build M=$(pwd)/drivers/net/wireguard modules
# install had some warnings, see below
sudo make -C /lib/modules/$(uname -r)/build M=$(pwd)/drivers/net/wireguard modules_install

sudo depmod -a
sudo update-initramfs -u

# sudo modinfo wireguard | grep filename
# should show something like
# filename:       /lib/modules/6.1.0-37-amd64/extra/wireguard.ko