At one point probably 10 years ago I had linux vm guests refuse to generate gpg keys, gpg insisted it needed the stupid blocking random device, and because the vm guest was not getting any "entropy" the process went nowhere. As an openbsd user naturally I was disgusted, there are many sane solutions to this problem, but I used none of them. Instead I found rngd a service to accept "entropy" from a network source and blasted it with the /dev/random from a fresh obsd guest on the same vm host. Mainly out of spite. "look here you little shit, this is how you generate random numbers"
Qemu added support for VirtIO RNG in 2012 [0] so depending on how accurate that 10 year figure is, you also could have used that to make your VM able to use the host system's entropy.
