Re: [libvirt] RFC: virtio-rng and /dev/urandom
Also, I do not believe /dev/urandom is FIPS compliant. Finally, the
refill
policy is different, so it is not really true the algorithm is the same.
All in all, other than a seed value it really doesn't make any sense. Of
course, none of this matters on newer Intel hardware ;)
Right, but there's always the point about people that use heterogeneous
hosts and cannot pass rdrand/rdseed to the guest. For these, we should
add a QEMU driver that uses rdrand/rdseed, and thus decouples virtio-rng
from the host /dev/* completely.
From the libvirt POV there are various possibilities:
- Libvirt can have a libvirt.conf parameter that says "ignore whatever is
specified in the guest XML if rdrand/rdseed is available, and instead use
rdrand/rdseed".
- Libvirt can allow specifying rdrand/rdseed _and_ an additional backend,
like this:
<backend model="cpu"/>
<backend model="random">/dev/random</backend>
and fallback to the second if rdrand/rdseed are not available.
Paolo