Re: [Qemu-devel] [PATCH] VirtIO-RNG: Update default entropy source to `/dev/urandom`

[Kashyap Chamarthy <kchamart@redhat.com>]

On Fri, May 03, 2019 at 04:49:05PM +0100, Daniel P. Berrangé wrote:
> On Fri, May 03, 2019 at 05:46:13PM +0200, Kashyap Chamarthy wrote:
> > When QEMU exposes a VirtIO-RNG device to the guest, that device needs a
> > source of entropy, and that source needs to be "non-blocking", like
> > `/dev/urandom`.  However, currently QEMU defaults to the problematic
> > `/dev/random`, which is "blocking" (as in, it waits until sufficient
> > entropy is available).
> > 
> > So change the entropy source to the recommended `/dev/urandom`.
> > 
> > Related discussion in these[1][2] past threads.
> > 
> > [1] https://lists.nongnu.org/archive/html/qemu-devel/2018-06/msg08335.html
> >     -- "RNG: Any reason QEMU doesn't default to `/dev/urandom`?"
> > [2] https://lists.nongnu.org/archive/html/qemu-devel/2018-09/msg02724.html
> >     -- "[RFC] Virtio RNG: Consider changing the default entropy source to
> >        /dev/urandom"
> > 
> > Signed-off-by: Kashyap Chamarthy <kchamart@redhat.com>
> > ---
> >  backends/rng-random.c | 2 +-
> >  qemu-options.hx       | 2 +-
> >  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

I'm wondering if this needs to be mentioned on a Release Notes wiki
somewhere -- because we're changing the default.

-- 
/kashyap