I am using Windows VM with GPU passthrough too.
If you want it out of the box (well, kinda) I would recommend Proxmox. Proxmox is amazing hypervisor OS. Otherwise you need to study tricky things a lot: QEMU, Kernel configuration for VFIO.
Also you may need hardware, especially motherboard that supports VFIO groups well.
Fortunatly there are quite big communities like Reddit in this topic. Just google "VFIO"
I'm not an expert in C, but then what's the issue with strncpy() or any "n" functions? It prevents overflow AFAIK. Also what is the alternative (memcpy?) and why?
Most CBOR implementations for MCUs tend to be a part of RTOSs, integrated and optimized for their own memory allocation libraries. But many of them are based on Intel's TinyCBOR: https://github.com/intel/tinycbor