Comment 1 for bug 1743191

Reverting to Seabios 1.10 (version rel-1.10.3.0-gb76661dd) fixes this problem.

Steps:

$ cd && mkdir seabios-test && cd seabios-test
$ git clone -b 1.10-stable https://github.com/coreboot/seabios.git
$ cd seabios
$ make
$ qemu-system-x86_64 \
-drive if=virtio,file=/home/oc/VM/img/netbsd.image,index=0,media=disk \
-M q35,accel=kvm -m 350M -cpu host -smp $(nproc) \
-nic user,model=virtio-net-pci,ipv6=off \
-nographic -bios /home/oc/seabios-test/seabios/out/bios.bin

Result:
I can interact with NetBSD boot menu and select one of the available options.

Host:
Linux e130 4.9.0-11-amd64 #1 SMP Debian 4.9.189-3+deb9u1 (2019-09-20) x86_64 GNU/Linux

QEMU emulator version 4.2.0