Jen, if you want to reproduce the issue I provided a docker image.
You just need docker (cf Install Docker Engine on Ubuntu | Docker Documentation) and then:
docker run --rm -ti --name testvirt quay.io/legato/virt-x86:2.2.1-alpha
This runs a Yocto 2.2.1 based x86 image in QEmu with a 4.8.12 kernel.
Because of the issue it reboots few seconds after the boot.
As to prevent that you can void the start-up script:
echo > /etc/init.d/startlegato.sh
As for the toolchain, you can use http://downloads.sierrawireless.com/legato/virt/poky-swi-glibc-x86_64-meta-toolchain-swi-i586-toolchain-swi-2.2.1.sh like this:
export VIRT_TOOLCHAIN_DIR=/opt/swi/y22
export VIRT_TARGET_ARCH=x86
export LEGATO_SYSROOT=/opt/swi/y22/sysroots/i586-poky-linux
make virt
The target also has an SSH server so you can use regular scripts like update or app install.
To get the IP:
docker inspect --format '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' testvirt
To stop the target just do:
docker kill testvirt