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From: Amos Kong <akong@redhat.com>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	linux-kernel@vger.kernel.org, hpa@linux.intel.com,
	ricardo.neri-calderon@linux.intel.com, tytso@mit.edu,
	Amit Shah <amit.shah@redhat.com>
Subject: Re: [PATCH] virtio: rng: add derating factor for use by hwrng core
Date: Fri, 15 Aug 2014 02:51:28 +0800	[thread overview]
Message-ID: <20140814185128.GA1894@z.redhat.com> (raw)
In-Reply-To: <87zjf88awc.fsf@rustcorp.com.au>

On Thu, Aug 14, 2014 at 04:39:07AM +0930, Rusty Russell wrote:
> The khwrngd thread is started when a hwrng device of sufficient
> quality is registered.  The virtio-rng device is backed by the
> hypervisor, and we trust the hypervisor to provide real entropy.
> 
> A malicious hypervisor is a scenario that's irrelevant -- such a setup
> is bound to cause all sorts of badness, and a compromised hwrng is not
> the biggest threat.
> 
> Given this, we are certain the quality of randomness we receive is
> perfectly trustworthy.  Hence, we use 100% for the factor, indicating
> maximum confidence in the source.
> 
> Signed-off-by: Amit Shah <amit.shah@redhat.com>
> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>


Reviewed-by: Amos Kong <akong@redhat.com>

> ---
> Pretty small and contained patch; would be great if it is picked up for
> 3.17.
> 
> v2: re-word commit msg
> 
> [Agreed, re-sending to Linus with SOB before jumping on plane]
> ---
>  drivers/char/hw_random/virtio-rng.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/char/hw_random/virtio-rng.c
> b/drivers/char/hw_random/virtio-rng.c
> index 0027137..2e3139e 100644
> --- a/drivers/char/hw_random/virtio-rng.c
> +++ b/drivers/char/hw_random/virtio-rng.c
> @@ -116,6 +116,7 @@ static int probe_common(struct virtio_device *vdev)
> 		.cleanup = virtio_cleanup,
> 		.priv = (unsigned long)vi,
> 		.name = vi->name,
> +		.quality = 1000,
> 	};
> 	vdev->priv = vi;
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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-- 
			Amos.

      parent reply	other threads:[~2014-08-14 18:51 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-13 19:09 [PATCH] virtio: rng: add derating factor for use by hwrng core Rusty Russell
2014-08-13 20:49 ` H. Peter Anvin
2014-08-13 22:44 ` Theodore Ts'o
2014-08-14 18:51 ` Amos Kong [this message]

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