Commit Graph

4 Commits

Author SHA1 Message Date
Peter Krempa
32bd699f55 virtio-rng: Add rate limiting options for virtio-RNG
Qemu's implementation of virtio RNG supports rate limiting of the
entropy used. This patch exposes the option to tune this functionality.

This patch is based on qemu commit 904d6f588063fb5ad2b61998acdf1e73fb4

The rate limiting is exported in the XML as:
<devices>
  ...
  <rng model='virtio'>
    <rate bytes='123' period='1234'/>
    <backend model='random'/>
  </rng>
  ...
2013-03-14 13:28:10 +01:00
Eric Blake
4932ef4502 rng: restrict passthrough names to known-good files
There is some controversy[1] on the qemu list on whether qemu should
have ever allowed arbitrary file name passthrough, or whether it
should be restricted to JUST /dev/random and /dev/hwrng.  It is
always easier to add support for additional filenames than it is
to remove support for something once released, so this patch
restricts libvirt 1.0.3 (where the virtio-random backend was first
supported) to just the two uncontroversial names, letting us defer
to a later date any decision on whether supporting arbitrary files
makes sense. Additionally, since qemu 1.4 does NOT support
/dev/fdset/nnn fd passthrough for the backend, limiting to just
two known names means that we don't get tempted to try fd
passthrough where it won't work.

[1]https://lists.gnu.org/archive/html/qemu-devel/2013-03/threads.html#00023

* src/conf/domain_conf.c (virDomainRNGDefParseXML): Only allow
/dev/random and /dev/hwrng.
* docs/schemas/domaincommon.rng: Flag invalid files.
* docs/formatdomain.html.in (elementsRng): Document this.
* tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.args:
Update test to match.
* tests/qemuxml2argvdata/qemuxml2argv-virtio-rng-random.xml:
Likewise.
2013-03-04 17:45:38 -07:00
Peter Krempa
2ab08e6cb1 tests: Test XML entities in source path for RNG device
Users may want to specify XML entities in paths to devices. Ensure they
are parsed and used properly.
2013-02-27 11:04:41 +01:00
Peter Krempa
e8b70ab743 tests: Add tests for virtio-rng device handling
Adds XML parsing and qemu commandline tests for the VirtIO RNG device
support.
2013-02-25 10:58:04 +01:00