  Embedded systems are pervasively used in many fields nowadays. In
mixed-criticality environments (automotive, industry 4.0, drones, etc.) they
need to run real-time applications with certain time and safety constraints
alongside a rich operating system (OS). This is usually possible thanks to
virtualization techniques, that leverage on hardware virtualization extensions
on the machine. However, these hardware extensions might not cope with the
security and safety requirements of the specific use case, and additionally,
they might not always be available. A notable example is the emerging RISC-V
architecture, that is today gaining a lot of traction in the mixed criticality
field, but that do not offer today hardware virtualization extensions. In this
paper VOSySmonitoRV is proposed as a mixed-criticality solution for RISC-V
systems. VOSySmonitoRVallows the co-execution of two or more operating systems
in a secure and isolated manner by running in the highest privileged machine
level. A specific benchmark, measuring the interrupt latency and context switch
time is done to assess the system performance in mixed criticality systems.
