I have followed this link to set up a kernel development environment. In summary, I am running a Linux kernel 5.11.5 with a custom root file system. I am using buildroot to creating a root file system. Now, the filesystem image size is fixed so I'm not able to even create a directory at runtime from within a guest. So, I am not able to create a swap space.
Please provide a way to create a swap space for a guest.