[bhyve][arm64] Number of allowed vcpus

[Peter Grehan]

Hi Andrei,

> While working on enabling multiple virtual cpus for the arm64 virtual
> machine
> I used the bhyve's "-c N" parameter to create N cpus (it gets only the
> cpus, in contrast to the amd64). If N is smaller than the number of cores
> described in the device tree it will enable only N and if it's larger it
> will enable only the number of cores from the device tree.
> 
> I don't know if it is the best approach. Another way would be to enable all
> the cpus from the device tree, no more, no less.
> 
> Do you have any suggestions?

  My suggestion to generate the device tree based on VM configuration. 
bhyve on amd64 already does this for ACPI tables.

  (I do understand that this is more difficult for bhyveload on ARM64 
since the device tree has to be known at load time, and bhyveload is 
only given a subset of parameters: however it may be possible to reserve 
space at a fixed location and then have bhyve copy a generated table 
into that region).

later,

Peter.