| ACPIVMGENID(4) | Device Drivers Manual | ACPIVMGENID(4) | 
acpivmgenid —
acpivmgenid* at acpi?
acpivmgenid provides a generation ID for virtual
  machines.
When starting two otherwise identical virtual machines, whether from the same clean image or by cloning snapshots or any other mechanism, the VM host may choose a different generation ID. Although this generation ID is not secret, it is incorporated into the entropy(7) pool (with a measure of zero entropy) so that the two virtual machines will produce independent random output.
If a live VM is cloned, the VM host may change the generation ID
    in one or both of the clones and notify them through the
    acpivmgenid device. When this happens,
    NetBSD will reseed system random number generators,
    so that output of /dev/urandom and
    getentropy(3) will be
    independent in the two clones, and the
    sysctl(7) variable
    kern.entropy.epoch will advance to notify
    applications that they should reseed random number generators from the
    system entropy pool.
hw.acpivmgenidN.idhw.acpivmgenidN.paddrVirtual Machine Generation ID, http://go.microsoft.com/fwlink/?LinkId=260709, Microsoft, 2018-08-01.
Virtual Machine Generation ID Device, https://www.qemu.org/docs/master/specs/vmgenid.html, The QEMU Project Developers.
acpivmgenid driver first appeared in
  NetBSD 10.1.
kern.entropy.epoch,
  not
  hw.acpivmgenidN.id.)
| August 26, 2024 | NetBSD 10.1 |