Re: [libvirt] virtio-rng and fd passing
[adding libvirt] On 03/03/2013 02:05 PM, Anthony Liguori wrote:
Paolo Bonzini <pbonzini@redhat.com> writes:
Il 02/03/2013 04:13, Anthony Liguori ha scritto:
There is no valid use-case of rng-random other than using /dev/random. In fact, it was probably a mistake to even allow a filename to be specified because it lets people do silly things (like /dev/urandom).
If you want anything other than /dev/random, you should use rng-egd.
/dev/hwrng makes sense too.
Good point. Perhaps we should issue a warning when anything is used other than /dev/random or /dev/hwrng to discourage people from doing the wrong thing. I completely understand the confusion and I think we should try a bit harder to prevent people from getting it wrong.
Then libvirt should also make sure that the XML we allow for non-egd virtio-rng is restricted to the two filenames that won't cause a qemu warning, or even modify the XML to not expose a filename in the first place. We haven't released libvirt 1.0.3 yet, so we still have a few hours in which such a change could be made before the XML becomes baked by a release. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
Eric Blake <eblake@redhat.com> writes:
[adding libvirt]
On 03/03/2013 02:05 PM, Anthony Liguori wrote:
Paolo Bonzini <pbonzini@redhat.com> writes:
Il 02/03/2013 04:13, Anthony Liguori ha scritto:
There is no valid use-case of rng-random other than using /dev/random. In fact, it was probably a mistake to even allow a filename to be specified because it lets people do silly things (like /dev/urandom).
If you want anything other than /dev/random, you should use rng-egd.
/dev/hwrng makes sense too.
Good point. Perhaps we should issue a warning when anything is used other than /dev/random or /dev/hwrng to discourage people from doing the wrong thing. I completely understand the confusion and I think we should try a bit harder to prevent people from getting it wrong.
Then libvirt should also make sure that the XML we allow for non-egd virtio-rng is restricted to the two filenames that won't cause a qemu warning, or even modify the XML to not expose a filename in the first place. We haven't released libvirt 1.0.3 yet, so we still have a few hours in which such a change could be made before the XML becomes baked by a release.
We've already released QEMU accepting any file name so we can't remove that functionality but I'm very much leaning toward producing such a warning for 1.5. It's such an easy mistake to make and it's extremely difficult to find good information on what you should and shouldn't do. I think that we (QEMU and libvirt) should try hard to steer people in the right direction. Regards, Anthony Liguori
-- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
On 03/04/2013 03:24 PM, Anthony Liguori wrote:
Then libvirt should also make sure that the XML we allow for non-egd virtio-rng is restricted to the two filenames that won't cause a qemu warning, or even modify the XML to not expose a filename in the first place. We haven't released libvirt 1.0.3 yet, so we still have a few hours in which such a change could be made before the XML becomes baked by a release.
We've already released QEMU accepting any file name so we can't remove that functionality but I'm very much leaning toward producing such a warning for 1.5.
It's such an easy mistake to make and it's extremely difficult to find good information on what you should and shouldn't do. I think that we (QEMU and libvirt) should try hard to steer people in the right direction.
It's too late for qemu 1.4, but libvirt 1.0.3 can still get it right. Proposed libvirt patch coming up soon. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
participants (2)
-
Anthony Liguori -
Eric Blake