Kernel panic when load of radeonkms is followed by load of amdgpu or i915kms

[grahamperrin]

Describe the bug

Examples:

• panic on real hardware that requires i915kms, after booting from a mobile hard disk drive that was preconfigured for radeonkms
• panics in a Virtualbox guest, when (for reproduction purposes) a combination of modules is loaded.

FreeBSD version

FreeBSD 14.0-CURRENT and 13.1-RELEASE.

PCI Info

For the HP notebook, which I booted from the mobile hard disk drive (14.0-CURRENT), I can't get details at the moment. (It's not my computer.)

Details below are for the VirtualBox guest (13.1-RELEASE).

pciconf -lv

```text hostb0@pci0:0:0:0: class=0x060000 rev=0x02 hdr=0x00 vendor=0x8086 device=0x1237 subvendor=0x0000 subdevice=0x0000 vendor = 'Intel Corporation' device = '440FX - 82441FX PMC [Natoma]' class = bridge subclass = HOST-PCI isab0@pci0:0:1:0: class=0x060100 rev=0x00 hdr=0x00 vendor=0x8086 device=0x7000 subvendor=0x0000 subdevice=0x0000 vendor = 'Intel Corporation' device = '82371SB PIIX3 ISA [Natoma/Triton II]' class = bridge subclass = PCI-ISA vgapci0@pci0:0:2:0: class=0x030000 rev=0x00 hdr=0x00 vendor=0x80ee device=0xbeef subvendor=0x15ad subdevice=0x0405 vendor = 'InnoTek Systemberatung GmbH' device = 'VirtualBox Graphics Adapter' class = display subclass = VGA em0@pci0:0:3:0: class=0x020000 rev=0x02 hdr=0x00 vendor=0x8086 device=0x100e subvendor=0x8086 subdevice=0x001e vendor = 'Intel Corporation' device = '82540EM Gigabit Ethernet Controller' class = network subclass = ethernet none0@pci0:0:4:0: class=0x088000 rev=0x00 hdr=0x00 vendor=0x80ee device=0xcafe subvendor=0x0000 subdevice=0x0000 vendor = 'InnoTek Systemberatung GmbH' device = 'VirtualBox Guest Service' class = base peripheral pcm0@pci0:0:5:0: class=0x040100 rev=0x01 hdr=0x00 vendor=0x8086 device=0x2415 subvendor=0x8086 subdevice=0x0000 vendor = 'Intel Corporation' device = '82801AA AC'97 Audio Controller' class = multimedia subclass = audio ohci0@pci0:0:6:0: class=0x0c0310 rev=0x00 hdr=0x00 vendor=0x106b device=0x003f subvendor=0x0000 subdevice=0x0000 vendor = 'Apple Inc.' device = 'KeyLargo/Intrepid USB' class = serial bus subclass = USB intsmb0@pci0:0:7:0: class=0x068000 rev=0x08 hdr=0x00 vendor=0x8086 device=0x7113 subvendor=0x0000 subdevice=0x0000 vendor = 'Intel Corporation' device = '82371AB/EB/MB PIIX4 ACPI' class = bridge ahci0@pci0:0:13:0: class=0x010601 rev=0x02 hdr=0x00 vendor=0x8086 device=0x2829 subvendor=0x0000 subdevice=0x0000 vendor = 'Intel Corporation' device = '82801HM/HEM (ICH8M/ICH8M-E) SATA Controller [AHCI mode]' class = mass storage subclass = SATA ```

DRM KMOD version

drm-510-kmod 5.10.113

To Reproduce

Boot with either of these listings in /etc/rc.conf:

• kld_list=radeonkms i915kms
• kld_list=radeonkms amdgpu

For the first of those two:

Dump header from device: /dev/gpt/freebsd-swap
  Architecture: amd64
  Architecture Version: 2
  Dump Length: 191676416
  Blocksize: 512
  Compression: none
  Dumptime: 2022-05-16 19:31:03 -0400
  Hostname: freebsd
  Magic: FreeBSD Kernel Dump
  Version String: FreeBSD 13.1-RELEASE releng/13.1-n250148-fc952ac2212 GENERIC
  Panic String: page fault
  Dump Parity: 4205894177
  Bounds: 8
  Dump Status: good

vmcore.8.txt

Additional context

From the thread (missing from archives) at https://gitter.im/FreeBSDDesktop/Lobby/archives/2022/05/16?at=6282929961f5ca3fee04c20f:

Whilst kld_list=amdgpu radeonkms does not panic the system, kldload can not load radeonkms.

Reportedly "module already loaded or in kernel" and kldstat | grep radeon does not list radeonkms.

Playing with fire (?) I can unload amdgpu then load radeonkms.

Subsequent unload of radeonkms succeeds, subsequent load of i915kms causes a panic with (extraordinarily) no prompt; no option to continue:

[wulf7]

Probably, there is a fix: https://github.com/dumbbell/drm-kmod/commit/0ebda877d01f4b97c48e9e49365829bd66da1a0e

[grahamperrin]

See also: FreeBSD bug 271897 – graphics/drm-510-kmod: loading amdgpu and i915kms kernel modules simultaneously causes the system to crash.

[octal-illumination]

Facing similar issue. I have installed drm-kmod, not sure if its drm-510-kmod. But in my case, setting kld_list="i915kms amdgpu" causes the system to not boot/panic/crash. Is there anything I should add to help solve the issue?. [Posted this comment at the bugs.freesd.org too].

[grahamperrin]

… when load of radeonkms is followed by load of amdgpu or i915kms

The 13.2-RELEASE kernel panic at https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=271897#c15 was:

• load of i915kms by rc(8)
• followed by kldload amdgpu.

root@fuji:~ # sysrc kld_list
kld_list: i915kms fusefs
root@fuji:~ # 

I'm inclined to treat 271897 as overlapping with (or the same as) this issue #168, and change the title here … @evadot please, would you agree?