bhyve(8): allow cpu pinning using N-M:X-Y ranges

[antranigv_freebsd.am]

Summary

bhyve's -p allows to pin guest's virtual CPU vcpu to hostcpu, however
this becomes very tedious work when you have to pin more than a single
CPU.

This allows to pass a range to -p, e.g. -p 0-3:4-7 which will pin the
cpus 0:4, 1:5, 2:6, 3:7. The ranges must be equal and the CPU numbers
must be ascending.

TODO: Updating the man page.

Sponsored by: Armenian Bioinformatics Institute

[corvink]

usr.sbin/bhyve/aarch64/bhyverun_machdep.c

103

usr.sbin/bhyve/amd64/bhyverun_machdep.c

81

usr.sbin/bhyve/riscv/bhyverun_machdep.c

98

[markj]

usr.sbin/bhyve/bhyverun.c

397

libutil has cpuset_parselist(). Can we use that here?

[antranigv_freebsd.am]

usr.sbin/bhyve/bhyverun.c

397

I can add it as a separate feature, but to my knowledge that’s not the same as CPU pinning, which pins specific vcpu’s to hostcpu’s (or in cpuset terminology: specific bhyve thread to a specific CPU).

I think it would be nice to set a cpuset on the fly using another flag (maybe -P if we’re not using it), instead of creating and using a cpuset every time.

I hope I understood your question correctly.

[markj]

usr.sbin/bhyve/bhyverun.c

397

I meant that you could use it to parse the CPU lists. It would make it easier to write something like -p 0-3:0,2,4,6 to pin 0->0, 1->2, 2->4, 3->6. But ok, this is fine for now.

413