  In this paper, we describe our approach to develop a simulation software
application for the fully kinetic Vlasov equation which will be used to explore
physics beyond the gyrokinetic model. Simulating the fully kinetic Vlasov
equation requires efficient utilization of compute and storage capabilities due
to the high dimensionality of the problem. In addition, the implementation
needs to be extensibility regarding the physical model and flexible regarding
the hardware for production runs. We start on the algorithmic background to
simulate the 6-D Vlasov equation using a semi-Lagrangian algorithm. The
performance portable software stack, which enables production runs on pure CPU
as well as AMD or Nvidia GPU accelerated nodes, is presented. The extensibility
of our implementation is guaranteed through the described software architecture
of the main kernel, which achieves a memory bandwidth of almost 500 GB/s on a
V100 Nvidia GPU and around 100 GB/s on an Intel Xeon Gold CPU using a single
code base. We provide performance data on multiple node level architectures
discussing utilized and further available hardware capabilities. Finally, the
network communication bottleneck of 6-D grid based algorithms is quantified. A
verification of physics beyond gyrokinetic theory for the example of ion
Bernstein waves concludes the work.
