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
---cc---
cc 8.3 [DragonFly] Release/2019-02-22
---cpu features---
QEMU Virtual CPU version 2.5+
---modules present---
ls: /boot/modules/: No such file or directory
amdgpu.ko
drm.ko
radeon.ko
radeonkmsfw_ARUBA_me.ko
radeonkmsfw_ARUBA_pfp.ko
radeonkmsfw_ARUBA_rlc.ko
radeonkmsfw_BARTS_mc.ko
radeonkmsfw_BARTS_me.ko
radeonkmsfw_BARTS_pfp.ko
radeonkmsfw_BARTS_smc.ko
---cpu feat leaf---
CPU: QEMU Virtual CPU version 2.5+ (3600.01-MHz K8-class CPU)
  Features=0x1783fbfd<FPU,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,MMX,FXSR,SSE,SSE2,HTT>
  AMD Features=0x20100800<SYSCALL,NX,LM>

--- guest hardware (PCI) ---
QEMU i440fx host (no audio, no GPU): virtio-net, virtio-blk, PIIX3 ISA/ATA bridges only.
pciconf -lv shows NO multimedia/audio class and NO display/VGA class devices.

--- relevant modules on disk (/boot/kernel/) ---
amdgpu.ko, drm.ko, radeon.ko, sound.ko, snd_*.ko all PRESENT but NONE loaded
(no matching hardware to attach). kldstat shows only kernel + ehci.ko + xhci.ko.

--- reachability of the cited code paths ---
* DF-1254/DF-1268/DF-1269/DF-1274 (dev/drm/amd): require an AMD GPU (radeon/amdgpu
  attach) which then parses VBIOS powerplay tables. No AMD GPU on guest => code path
  dead at runtime. Triggering needs crafted VBIOS on real AMD hardware.
* DF-1260 (dev/sound/pcm/dsp.c AIOGCAP): requires a registered pcm device (/dev/dsp
  openable). sound.ko loads and creates /dev/dsp but no snd_* bridge driver attaches
  (no audio HW) so /dev/dsp open fails (no pcm device registered, /dev/sndstat empty).
  Bug needs mixer_dev==NULL which needs a real snd_* attach with failed mixer_init.