Re: regarding the changes to kernel entropy gathering

[Thomas Klausner <wiz%NetBSD.org@localhost>]

On Sun, Apr 04, 2021 at 11:14:31AM -0700, John Nemeth wrote:
>      I understand the need for good random sources, and won't argue
> it.  My question is, how can we tell what random sources a system
> actually has, i.e. is there some flag that cpuctl identify shows
> when a system has RDRAND/RDSEED?  Are there other sources that can
> be positively identified as providing randomness?

That should do it:

# cpuctl identify 0 | grep -e RDRAND -e RDSEED 
cpu0: features1 0x7ed8320b<MOVBE,POPCNT,AES,XSAVE,OSXSAVE,AVX,F16C,RDRAND>
cpu0: features5 0x209c01a9<FSGSBASE,BMI1,AVX2,SMEP,BMI2,RDSEED,ADX,SMAP>

 Thomas