Download the vSRX QCOW2 image from the Juniper software download site.
https://www.juniper.net/support/downloads/?p=vsrx#sw
or
( fron the cmd of the KVM hypervisor ) wget + the link below
Set RAM to 4096 MB and
set CPUs to 2
disk image size to 16 GB
See next page:
<feature policy='force' name='vmx'/>
<feature policy='disable' name='invtsc'/>
It take very look time to boot-up ( could use: virsh start vSRCVM --console )