Guest environment for the DF-2834 / DF-2835 verification (2026-10-20 UTC).

uname -a (stock kernel, baseline runs):
  DragonFly dfbsd 6.5-DEVELOPMENT DragonFly 6.5-DEVELOPMENT #0: Thu Jul  2 06:02:54 UTC 2026     root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC  x86_64

kern.version (stock):
  DragonFly 6.5-DEVELOPMENT #0: Thu Jul  2 06:02:54 UTC 2026
  root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC

patched kernel used for fix validation A/B:
  DragonFly 6.5-DEVELOPMENT #1: Tue Oct 20 11:55:22 UTC 2026
  root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC
  (built in guest /usr/src with: make -j6 nativekernel KERNCONF=X86_64_GENERIC)

QEMU/KVM: dfbsd-qemu/vm.sh, -m 4096 -smp 6, snapshot with-src
compiler: cc 8.3 [DragonFly] Release/2019-02-22
hw.ncpu: 6
hw.physmem: 4257873920  (1,039,519 pages of 4096 B)
vm.vkernel_enable: 0 at boot (default). Set to 1 for the test windows by
  root; restored to 0 after each window (directive compliance).
vm.max_proc_mmap: 1000000   (mmap entries ARE capped; no analogous
  vmspace cap existed before the fix)
baselines (quiescent, stock): vm.stats.vm.v_wire_count ~123127 (fresh boot)
  / ~143045 (pre-run), vm.kvm_free 8791376523264,
  vm.stats.vm.v_free_count ~849484
new sysctl after fix: vm.max_vkernel_vmspaces (default 64)

Post-verification hygiene: vm.vkernel_enable=0 confirmed, then
`vm.sh reset with-src` (patched kernel discarded, clean snapshot restored).
guest_dirty = 0.