| Message ID | 6f2df652355d6e78da846d06e32489b7d9cdfcc2.1407782982.git.amit.shah@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 08/11/2014 11:49 AM, Amit Shah wrote: > 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@redhat.com> It isn't "ruled out", it is just irrelevant: if the hypervisor is malicious, the quality of your random number source is the least of your problems. -hpa -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On (Mon) 11 Aug 2014 [15:11:03], H. Peter Anvin wrote: > On 08/11/2014 11:49 AM, Amit Shah wrote: > > 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@redhat.com> > > It isn't "ruled out", it is just irrelevant: if the hypervisor is > malicious, the quality of your random number source is the least of your > problems. Yea; I meant ruled out in that sense. Should the commit msg be more verbose? Amit -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 08/11/2014 10:27 PM, Amit Shah wrote: > On (Mon) 11 Aug 2014 [15:11:03], H. Peter Anvin wrote: >> On 08/11/2014 11:49 AM, Amit Shah wrote: >>> 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@redhat.com> >> >> It isn't "ruled out", it is just irrelevant: if the hypervisor is >> malicious, the quality of your random number source is the least of your >> problems. > > Yea; I meant ruled out in that sense. Should the commit msg be more > verbose? > Yes, as it is written it is misleading. -hpa -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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;
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@redhat.com> --- 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(+)