>> > This patch adds support for virtio-rng. Data is read from a >> > chardev and can be either raw entropy or received via the EGD protocol. >> >> I still don't get why you need this at all. It seems like >> virtio-serial would already provides everything you need. > >I guess when virtio-rng was first written, virtio-serial wasn't >flexible enough because it didn't support multiple devices
That argument no longer holds. > and maybe virtio-rng is still needed to enforce the EGD protocol when that > is being used. Maybe, though the benefit of having this knowledge in wemu seems somewhat unclear. If we do want it then shouldn't be be implemented as a char device backend, rather than part of a specific serial port implementation? > > > + qemu_gettimeofday(&now); > > > > Using qemu_gettimeofday is almost certainly wrong, and you want to > > be using virtual time. Plus I'm not convinced this is the right > > place to enforce rate limiting. > > If it's for rate limiting how fast the guest can take entropy from the > host, to ensure the host's entropy cannot be exhausted by a single > greedy guest, then perhaps qemu_gettimeofday() is right here. I doubt > if virtual time is right, at least not by itself. gettimeofday can and does jump arbitrarily. Comparing returned values is almost always wrong. Paul
