From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Smith Subject: Re: [Xen Hackathon] new PV drivers Date: Mon, 9 Jun 2014 19:16:19 +0000 Message-ID: <20140609191619.GZ21583@bitfolk.com> References: <1402304558.14895.8.camel@kazak.uk.xensource.com> <5395C50E.6010705@oracle.com> <1402324439.23103.7.camel@kazak.uk.xensource.com> <5395C73A.8060007@oracle.com> <1402325021.23103.8.camel@kazak.uk.xensource.com> <5395CAC6.3050205@oracle.com> <1402326385.23103.10.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1402326385.23103.10.camel@kazak.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org Hello, On Mon, Jun 09, 2014 at 04:06:25PM +0100, Ian Campbell wrote: > On Mon, 2014-06-09 at 10:55 -0400, Boris Ostrovsky wrote: > > Feeding is done by interrupt timing and block device access latency, > > both of which are happening in a guest. I don't know whether there is > > enough of that but perhaps before embarking on new PV driver it may be > > worth investigating quality of existing entropy source. Or maybe it's > > already been looked at. > > I've not done the numbers/investigated it myself but it's a quite widely > held belief that those things are not sufficient in a virtual machine. Available entropy in my VMs is much lower than on the dom0, to the point where I had customers doing a lot of HTTPS/TLS who were expeirencing stalls. I bought a couple of Entropy Keys and shipped in entropy to the VMs via an additional daemon. https://tools.bitfolk.com/wiki/Entropy A software solution to seed entropy in VMs from the dom0's pool would be welcome. Cheers, Andy