  With the exponentially increasing demand for performance and scalability in
cloud applications and systems, data center architectures evolved to integrate
heterogeneous computing fabrics that leverage CPUs, GPUs, and FPGAs. FPGAs
differ from traditional processing platforms such as CPUs and GPUs in that they
are reconfigurable at run-time, providing increased and customized performance,
flexibility, and acceleration. FPGAs can perform large-scale search
optimization, acceleration, and signal processing tasks compared with power,
latency, and processing speed. Many public cloud provider giants, including
Amazon, Huawei, Microsoft, Alibaba, etc., have already started integrating
FPGA-based cloud acceleration services. While FPGAs in cloud applications
enable customized acceleration with low power consumption, it also incurs new
security challenges that still need to be reviewed. Allowing cloud users to
reconfigure the hardware design after deployment could open the backdoors for
malicious attackers, potentially putting the cloud platform at risk.
Considering security risks, public cloud providers still don't offer
multi-tenant FPGA services. This paper analyzes the security concerns of
multi-tenant cloud FPGAs, gives a thorough description of the security problems
associated with them, and discusses upcoming future challenges in this field of
study.
