On Thu, 2020-01-23 at 16:16 +0100, Laurent Vivier wrote: > The kernel needs sometime to be able to cancel an ongoing command. > > For instance, if the virtio-rng device uses the egd backend > and this backend doesn't provide data, the buffer provided by the > kernel is kept as long as it is needed. > > On the kernel side, a read blocks until the buffer returns from QEMU. > > As the read is done with a mutex held, all the hw_random interface > hangs and we cannot switch to another hw_random backend. > > So this series adds a control queue to the virtio-rng device to allow > to flush the virtio-rng input queue to release the kernel mutex and > to allow to switch to another device. > > The kernel side series can be found at: > > https://github.com/vivier/linux/commits/virtio-rng-ctrl
Did you submit the kernel series too? Can you please CC me to it? This will need spec changes as well, can you please point me to them too? I also recall a previous discussion about this, but my search-fu is failing to find it... Amit