From: Sasha Levin <levinsasha928@gmail.com>
To: "Ted Ts'o" <tytso@mit.edu>
Cc: Sandy Harris <sandyinchina@gmail.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: random(4) driver questions
Date: Mon, 27 Jun 2011 11:08:13 -0400 [thread overview]
Message-ID: <1309187293.15376.3.camel@lappy> (raw)
In-Reply-To: <20110627145442.GA2729@thunk.org>
On Mon, 2011-06-27 at 10:54 -0400, Ted Ts'o wrote:
> > What happens to /dev/random when it runs on
> > a virtual machine and all the things it relies on
> > for entropy get virtualised away?
> >
> > The server that the VM is hosted on will usually
> > have plenty of entropy, often a hardware RNG.
> > Is there an interface that makes that visible
> > from the VM? Perhaps a virtual "hardware"
> > RNG driven by /dev/urandom on the host?
>
> Yes, paravirtualizing the random number generator would be a big help.
> Probably what I would do is to periodically add entropy from the host
> OS to the guest OS, via some paravirt channel. This would add a new
> "catastrophic reseeding", and if the virtual guest can mix in some
> other unknown material, again that can only help.
virtio has a 'virtio-rng' device which does just that.
--
Sasha.
next prev parent reply other threads:[~2011-06-27 15:08 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-25 5:51 random(4) driver questions Sandy Harris
2011-06-25 12:53 ` Alexander Clouter
2011-06-27 14:54 ` Ted Ts'o
2011-06-27 15:08 ` Sasha Levin [this message]
2011-06-28 4:44 ` Johann Meier
2011-06-28 5:47 ` Sandy Harris
2011-06-28 19:44 ` Henrique de Moraes Holschuh
2011-06-28 6:02 ` Sandy Harris
2011-06-28 14:42 ` Ted Ts'o
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1309187293.15376.3.camel@lappy \
--to=levinsasha928@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=sandyinchina@gmail.com \
--cc=tytso@mit.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox