Re: [PATCH 0/3] Add support for Graviton TRNG

From: Saidi, Ali
Date: Fri Jun 07 2019 - 09:03:00 EST

ïOn 6/5/19, 7:20 AM, "Will Deacon" <will.deacon@xxxxxxx> wrote:

On Tue, Jun 04, 2019 at 08:30:57PM +0000, Ali Saidi wrote:
> AWS Graviton based systems provide an Arm SMC call in the vendor defined
> hypervisor region to read random numbers from a HW TRNG and return them to the
> guest.
> We've observed slower guest boot and especially reboot times due to lack of
> entropy and providing access to a TRNG is meant to address this.

Curious, but why this over something like virtio-rng?

This interface allows us to provide the functionality from both EL2 and EL3 and support multiple different types of our instances which we unfortunately can't do with virt-io.