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Date: Wed, 31 Oct 2012 15:27:14 +0100
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Subject: Re: [Qemu-devel] [PATCH 0/6] add paravirtualization hwrng support
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To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Amit Shah <amit.shah@redhat.com>, Anthony Liguori <aliguori@us.ibm.com>, Andreas Faerber <afaerber@suse.de>, qemu-devel@nongnu.org

Il 31/10/2012 15:15, H. Peter Anvin ha scritto:
>>
>> Related to this, rdrand's "entropy content" in the worst case will be
>> only 1/255th of the data it produces: Intel documents that one 256-bit
>> seed will result in up to 1022 64-bit random numbers.  Yet, it is good
>> enough to drive rngd.  Would it make sense for QEMU to implement the
>> same kind of stretching of /dev/random data, to avoid depleting the
>> host's entropy pool too fast?
>>
> 
> Absolutely not; in fact, we have to do data reduction in rngd for
> exactly this reason (and a Qemu backend would have to do the same).
> There is a new RDSEED instruction in newer CPUs to correct this.

Ok, thanks.  At least I asked. :)

Paolo