The issue is with being externally observable and controllable, or, with
some irq mitigation schemes, be made /too regular/.
Interrupts (or timed mitigation events) may be triggered by the outside
world, which makes it a very short path from remote attacker to local
kernel entropy pool.
Finally, with severe load, there are little or no interrupts thanks to
heavy mitigation, which means your entropy pool may be externally DoS'd.
Or at the very least, when your entropy needs to be INCREASED (due to
heavy workload due to heavy traffic), your incoming entropy DECREASES
due to decreased interrupts.
[I just realized that last one. Heck, I'm even convincing myself even
more its a bad idea]
Jeff
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