[Bug 271330] struct vm_exit requires userland cpuset_t to be MAXCPU-sized

From: <bugzilla-noreply_at_freebsd.org>
Date: Tue, 09 May 2023 13:53:13 UTC

            Bug ID: 271330
           Summary: struct vm_exit requires userland cpuset_t to be
           Product: Base System
           Version: CURRENT
          Hardware: Any
                OS: Any
            Status: New
          Severity: Affects Only Me
          Priority: ---
         Component: kern
          Assignee: bugs@FreeBSD.org
          Reporter: emaste@freebsd.org
            Blocks: 269572

In 76887e84be97 I increased the userland maximum size for cpuset_t to 1024
cores, but corvink reported it broke bhyve

> vmm kernel module and bhyve userland are sharing a cpuset_t. So, this
> commit introduces a mismatch in the ioctl signature of VM_RUN.

mjg adds:

> On one hand this really should not be a part of the abi (you could
> have a pointer to cpuset and a a var stating the size).
> On the other hand, i suspect the least problematic long term solution
> is to introduce usercpuset_t (or whatever the name) and have a
> conversion func on import. This would still mean you need a kernel and
> user variant of the vm_exit struct.

Referenced Bugs:

[Bug 269572] MAXCPU too low for contemporary servers
You are receiving this mail because:
You are the assignee for the bug.