On 02/21/2013 07:47 AM, Peter Krempa wrote:
Qemu's implementation of virtio RNG supports rate limiting of the entropy used. This patch exposes the option to tune this fucntionality.
s/fucntionality/functionality/
This patch is based on qemu commit 904d6f588063fb5ad2b61998acdf1e73fb4
The rate limiting is exported in the XML as: <devices> ... <rng model='virtio'> <rate period='1234'>4321</rate>
So period='nnn', if provided, is in milliseconds?
<backend model='random'/> </rng> ... ---
Notes: Version 2: - Qemu uses bytes/period, adapt the value according to that
@@ -4315,6 +4316,14 @@ qemu-kvm -net nic,model=? /dev/null <li>'virtio' — supported by qemu and virtio-rng kernel module</li> </ul> </dd> + <dt><code>rate</code></dt> + <dd> + <p> + The rate parameter allows to limit the rate that the entropy can be + read from the source. The value is in bits that the device is allowed + to read in the selected period. The default period is 1000ms or 1 second. + </p>
This documentation didn't quite make it clear that 'period' is an optional attribute in milliseconds. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org