virtio-rnd provides a hardware random source for UOS. The virtual random device is based on virtio user mode framework and simulates a PCI device based on virtio specification.
Figure 201 shows the Random Device Virtualization Architecture in ACRN. virtio-rnd is implemented as a virtio legacy device in the ACRN device model (DM), and is registered as a PCI virtio device to the guest OS (UOS).
When the FE driver requires some random bytes, the BE device will place bytes of random data onto the virtqueue.
Tools such as
od can be used to read randomness from
/dev/random. This device file in UOS is bound with frontend
virtio-rng driver (The guest kernel must be built with
CONFIG_HW_RANDOM_VIRTIO=y). The backend virtio-rnd reads the HW
/dev/random in SOS and sends them to frontend.
To launch the virtio-rnd device, use the following virtio command:
To verify the correctness in user OS, use the following command: