DF-4053 + DF-4054 batched single-fix kernel build (guest dfbsd, 6 vcpu KVM)
============================================================================
Source state: /usr/src at snapshot with-src, with exactly two patches applied:
  patch -p1 < fix.4053.diff  (sys/dev/virtual/virtio/scsi/virtio_scsi.c — hunk #1 succeeded at 1389)
  patch -p1 < fix.4054.diff  (sys/dev/drm/amd/powerplay/hwmgr/vega12_hwmgr.c — hunk #1 succeeded at 482)

Command:
  cd /usr/src && make -j6 nativekernel KERNCONF=X86_64_GENERIC   # ~22 min
  cd /usr/src && make installkernel KERNCONF=X86_64_GENERIC

Live-captured output during the session (kbuild.log was in /tmp which the
validation reboot cleared; the machine-verifiable artifacts survive):

  --------------------------------------------------------------
  >>> Kernel build for X86_64_GENERIC completed on Thu Sep 17 19:36:04 UTC 2026
  --------------------------------------------------------------
  RC=0
  (4299 compile/link commands logged before the clear)

  IK-RC=0
  --------------------------------------------------------------
  >>> Kernel install for X86_64_GENERIC completed on Thu Sep 17 19:40:20 UTC 2026
  --------------------------------------------------------------

Post-reboot verification (both fixes present in the RUNNING kernel):
  DragonFly dfbsd 6.5-DEVELOPMENT DragonFly 6.5-DEVELOPMENT #1: Thu Sep 17 19:32:20 UTC 2026
      root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC  x86_64
  -rwxr-xr-x 1 root wheel  15705800 Sep 17 19:38 /boot/kernel.old/kernel   (stock #0)
  -r-xr-xr-x 1 root wheel 119340584 Sep 17 19:39 /boot/kernel/kernel       (patched #1, with debug)

Behavior delta (see run.log / run.patched.log):
  stock  #0: CHECK CONDITION + CAM_AUTOSNS_VALID + sense_data all 0x00
  patched#1: sense 70 00 05 00 00 00 00 0a 00 00 00 00 21 00 00 00
             (ILLEGAL REQUEST, ASC 0x21 LBA out of range) — fix works.