VirtIO random number device
viornd* at virtio? flags 0x00
driver provides a virtual random
number generator using a
provided by QEMU 1.3 and later, and possibly by other hypervisors.
As there is currently no way for
determine how much entropy is needed, the second byte of the flags value can
be used to configure how often it should request more entropy from the host.
If the second lowest byte of the flags has a value from 1 to 15,
will ask for 16 bytes of entropy
every 15 * (1 << value) seconds. For example, flags == 0x100 means an
interval of 30 seconds, 0x500 means 8 minutes, 0xa00 means 256 minutes, and
0xf00 means about 6 days. For flags == 0, a default value will be used
(currently 8 minutes). If the bit 0x1000 is set in the flags,
will only request entropy from the
host once during system boot.
driver first appeared in
driver was written by