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From: "H. Peter Anvin" <hpa@zytor.com>
To: Amit Shah <amit.shah@redhat.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>, Ted Ts'o <tytso@mit.edu>,
	Dustin Kirkland <kirkland@canonical.com>,
	qemu-devel@nongnu.org, George Wilson <gcwilson@us.ibm.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Kent Yoder <key@linux.vnet.ibm.com>,
	Andreas Faerber <afaerber@suse.de>
Subject: Re: [Qemu-devel] [PATCH 0/6] add paravirtualization hwrng support
Date: Mon, 29 Oct 2012 21:32:24 -0700	[thread overview]
Message-ID: <508F5858.5050606@zytor.com> (raw)
In-Reply-To: <20121029062308.GA3564@amit.redhat.com>

On 10/28/2012 11:23 PM, Amit Shah wrote:
> One solution could be to feed host's /dev/urandom to readers of
> guests' /dev/urandom.  We could then pass the rare true entropy bits
> from host's /dev/hwrng or /dev/random to the guest via
> virtio-rng-pci's /dev/hwrng interface in the guest.
>
> If this is a valid idea (host /dev/urandom goes directly to guest's
> /dev/urandom), we would need some guest-side surgery, but it shouldn't
> be huge work, and would remove several bottlenecks.
>
> Is this a very crazy idea?

It's not crazy, it's just pointless.  You're doing a completely 
unnecessary hypercall to run the PRNG in host space.

	-hpa


-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

  reply	other threads:[~2012-10-30  4:32 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-26 14:43 [Qemu-devel] [PATCH 0/6] add paravirtualization hwrng support Anthony Liguori
2012-10-26 14:43 ` [Qemu-devel] [PATCH 1/6] vl: add -object option to create QOM objects from the command line Anthony Liguori
2012-10-26 14:43 ` [Qemu-devel] [PATCH 2/6] object: add object_property_add_bool (v2) Anthony Liguori
2012-10-26 14:43 ` [Qemu-devel] [PATCH 3/6] rng: add RndBackend abstract object class Anthony Liguori
2012-10-26 14:43 ` [Qemu-devel] [PATCH 4/6] rng-random: add an RNG backend that uses /dev/random Anthony Liguori
2012-10-26 14:43 ` [Qemu-devel] [PATCH 5/6] rng-egd: introduce EGD compliant RNG backend Anthony Liguori
2012-10-26 14:43 ` [Qemu-devel] [PATCH 6/6] virtio-rng: hardware random number generator device Anthony Liguori
2012-10-26 15:08 ` [Qemu-devel] [PATCH 0/6] add paravirtualization hwrng support Paolo Bonzini
2012-10-26 15:42   ` Anthony Liguori
2012-10-26 16:09     ` H. Peter Anvin
2012-10-26 18:24       ` Anthony Liguori
2012-10-26 18:26         ` H. Peter Anvin
2012-10-29  6:23         ` Amit Shah
2012-10-30  4:32           ` H. Peter Anvin [this message]
2012-10-26 18:58       ` Paolo Bonzini
2012-10-26 19:07         ` H. Peter Anvin
2012-10-26 19:51           ` Paolo Bonzini
2012-10-26 19:54             ` H. Peter Anvin
2012-10-26 20:29             ` H. Peter Anvin
2012-10-29  8:45               ` Paolo Bonzini
2012-10-30  4:34                 ` H. Peter Anvin
2012-10-30  4:43                 ` H. Peter Anvin
2012-10-30  9:05                   ` Paolo Bonzini
2012-10-30 21:11                     ` H. Peter Anvin
2012-10-31  7:29                       ` Paolo Bonzini
2012-10-31 14:15                         ` H. Peter Anvin
2012-10-31 14:27                           ` Paolo Bonzini
2012-10-26 18:53     ` Paolo Bonzini
2012-10-29  7:01 ` Amit Shah

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