Re: [PATCH 1/2] rngd: add udev rule to source from hwrng if virtio-rng present

From: Torsten Duwe
Date: Mon Aug 11 2014 - 09:30:39 EST


On Mon, Aug 11, 2014 at 12:45:27PM +0530, Amit Shah wrote:
>
> What's the suggested value for rng->quality, though, for virtio-rng
> that I can use to ensure the kthread starts?
>
> Should I use the 700 (70%) as proposed in the original patchset? I'm
> not exactly sure how that value will be used as well..

There is no such thing as a suggested value, every number is wrong
to some degree. The quality is an estimation of how random your
source really is; it's a property of your hardware. If the device is
virtual you're in trouble ;-)

Either you have a way to query the underlying real hardware, or
you do your whitening and entropy estimation in the backend driver --
then you can claim 100%.

Torsten

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