From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: Re: Virt RNG? Date: Fri, 16 May 2008 09:43:08 +1000 Message-ID: <200805160943.08788.rusty@rustcorp.com.au> References: <482C8595.5030509@garzik.org> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <482C8595.5030509@garzik.org> Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: Jeff Garzik Cc: LKML , virtualization@lists.osdl.org, jeremy@xensource.com, Herbert Xu , Avi Kivity , Christian Borntraeger List-Id: virtualization@lists.linuxfoundation.org On Friday 16 May 2008 04:48:53 Jeff Garzik wrote: > Has anyone yet written a "hw" RNG module for virt, that reads the host's > random number pool? > > All this talk[1] about IRQF_SAMPLE_RANDOM in network drivers reminds me > that virt guest instances should be grabbing random numbers from the > host, especially if the host has a hardware RNG. Yes, I prepared one earlier. I was a little surprised to see that hwrng drivers don't contribute in any way to the entropy pool though, but now reading the thread I find out about rngd (not installed on my Ubuntu system, but available at least). One could argue that virtual rng should try to feed the kernel rng directly, with or without entropy credit. Anyway, since there's interest, I'll drag virtio_rng from the bottom of the queue, apply Christian's fix (which I somehow missed before, sorry Christian), and re-post. Thanks, Rusty.