Re: Linux messages full of `random: get_random_u32 called from`

From: Theodore Y. Ts'o
Date: Thu Apr 26 2018 - 20:00:28 EST


On Thu, Apr 26, 2018 at 10:47:49PM +0200, Christian Brauner wrote:
>
> We have observed a similiar problem with libvirt. As soon as entropy is
> provided the boot finishes otherwise it hangs for a long time.
> This is not happening with v4.17-rc1 afaict.

For libvirt there is at least an easy workaround. Make surue the
guest kernel has CONFIG_HW_RANDOM_VIRTIO enabled, and then make sure
qemu is started with the options:

-object rng-random,filename=/dev/urandom,id=rng0 \
-device virtio-rng-pci,rng=rng0

Cheers,

- Ted