virtio: rng: add derating factor for use by hwrng core The khwrngd thread is started when a hwrng device of sufficient quality is registered. The virtio-rng device is backed by the hypervisor, and we trust the hypervisor to provide real entropy. A malicious or badly-implemented hypervisor is a scenario that's irrelevant -- such a setup is bound to cause all sorts of badness, and a compromised hwrng is the least of the user's worries. Given this, we might as well assume that the quality of randomness we receive is perfectly trustworthy. Hence, we use 100% for the factor, indicating maximum confidence in the source. Signed-off-by: Amit Shah <amit.shah@redhat.com> Reviewed-by: H. Peter Anvin <hpa@linux.intel.com> Reviewed-by: Amos Kong <akong@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c index 0027137..2e3139e 100644 --- a/drivers/char/hw_random/virtio-rng.c +++ b/drivers/char/hw_random/virtio-rng.c
@@ -116,6 +116,7 @@ .cleanup = virtio_cleanup, .priv = (unsigned long)vi, .name = vi->name, + .quality = 1000, }; vdev->priv = vi;