[PATCH 1/1] virtio: rng: add derating factor for use by hwrng core

[Amit Shah]

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 hypervisor is a scenario that's ruled out, so we are certain
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@xxxxxxxxxx>

---
Pretty small and contained patch; would be great if it is picked up for
3.17.
---
 drivers/char/hw_random/virtio-rng.c | 1 +
 1 file changed, 1 insertion(+)

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 @@ static int probe_common(struct virtio_device *vdev)
 		.cleanup = virtio_cleanup,
 		.priv = (unsigned long)vi,
 		.name = vi->name,
+		.quality = 1000,
 	};
 	vdev->priv = vi;
 
-- 
1.9.3

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