Hello,

Xorg doesn't start anymore in a virtual e5500 QEMU KVM HV machine [1] 
with the VirtIO GPU after the DRM updates 'drm-next-2021-11-03' [2] on a 
Freescale P5040 board (A-EON AmigaOne X5000/40) [3]. (See error messages 
[4] [5])
I reverted the VirtIO GPU changes from the latest DRM updates [2]. After 
that, the VirtIO GPU works without any problems. The VirtIO GPU works 
also before the release of the latest DRM updates [2]. (See screenshot [6])

Could you please check the VirtIO GPU changes in the latest DRM updates [2]?

Please find attached the kernel config.

Thanks,
Christian

[1] qemu-system-ppc64 -M ppce500 -cpu e5500 -m 1024 -kernel uImage 
-drive format=raw,file=MintPPC32-X5000.img,index=0,if=virtio -netdev 
user,id=mynet0 -device virtio-net-pci,netdev=mynet0 -append "rw 
root=/dev/vda" -device virtio-vga -device virtio-keyboard-pci -device 
virtio-mouse-pci -smp 3
[2] 
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=56d33754481fe0dc7436dc4ee4fbd44b3039361d
[3] http://wiki.amiga.org/index.php?title=X5000
[4] Error messages in a virtual MintPPC machine (Debian):

Debian GNU/Linux bullseye/sid debian ttyS0

debian login: BUG: Kernel NULL pointer dereference on read at 0x00000018
Faulting instruction address: 0xc00000000075055c
Oops: Kernel access of bad area, sig: 11 [#1]
BE PAGE_SIZE=4K SMP NR_CPUS=4 QEMU e500
Modules linked in:
CPU: 0 PID: 2418 Comm: Xorg Not tainted 
5.16.0-a2_A-EON_X5000-07264-gff0700f03609-dirty #1
NIP:  c00000000075055c LR: c000000000750550 CTR: c000000000750548
REGS: c00000000ae737f0 TRAP: 0300   Not tainted 
(5.16.0-a2_A-EON_X5000-07264-gff0700f03609-dirty)
MSR:  0000000090029002 <CE,EE,ME>  CR: 24022288  XER: 00000000
DEAR: 0000000000000018 ESR: 0000000000000000 IRQMASK: 0
GPR00: c0000000001bd678 c00000000ae73a90 c000000001993600 c00000000a077000
GPR04: c00000000ae73c10 0000000000000001 c00000000a098270 c00000000cafc400
GPR08: c0000000017f2f88 0000000000000000 c0000000018e2418 018c3e5000413614
GPR12: 0000000084082282 c000000001a68000 00000000ffaee5a4 0000000000ee613c
GPR16: 0000000000efa53c 0000000000ca5040 000000000000000c 0000000000000000
GPR20: c000000002892598 c00000000a077030 0000000000000000 000000000a077000
GPR24: 000000000af9d300 c00000000af9d300 0000000000000000 c00000000a077000
GPR28: c00000000a448280 c000000002892580 c00000000a098260 c00000000a5aa400
NIP [c00000000075055c] .virtio_gpu_poll+0x14/0x134
LR [c000000000750550] .virtio_gpu_poll+0x8/0x134
Call Trace:
[c00000000ae73a90] [c00000000ae73b10] 0xc00000000ae73b10 (unreliable)
[c00000000ae73b20] [c0000000001bd678] .ep_item_poll+0x5c/0x80
[c00000000ae73ba0] [c0000000001beb5c] .do_epoll_ctl+0x604/0x878
[c00000000ae73ca0] [c0000000001bee14] .__se_sys_epoll_ctl+0x44/0x8c
[c00000000ae73d50] [c00000000000b0d4] .system_call_exception+0x11c/0x148
[c00000000ae73e10] [c0000000000001f8] system_call_common+0xf0/0x210

--- interrupt: c00 at 0x33c634

NIP:  000000000033c634 LR: 0000000000e11ea8 CTR: 0000000000000000
REGS: c00000000ae73e80 TRAP: 0c00   Not tainted 
(5.16.0-a2_A-EON_X5000-07264-gff0700f03609-dirty)
MSR:  000000001002d002 <CE,EE,PR,ME>  CR: 46000224  XER: 00000000
IRQMASK: 0
GPR00: 00000000000000ed 00000000ffaee3d0 00000000f7aa8340 0000000000000003
GPR04: 0000000000000001 000000000000000c 00000000ffaee3e8 00000000018c3e48
GPR08: 0000000000000011 0000000000000000 0000000000000000 0000000000000000
GPR12: 0000000000000000 0000000000edfff4 00000000ffaee5a4 0000000000ee613c
GPR16: 0000000000efa53c 0000000000ca5040 0000000000000000 0000000000c97330
GPR20: 0000000000c9b800 00000000fffffffc 0000000000000003 0000000001641fb0
GPR24: 000000000174f270 0000000000e0c800 0000000000000001 000000000000000c
GPR28: 0000000001642220 00000000018c3e50 0000000000ee7628 0000000000000003
NIP [000000000033c634] 0x33c634
LR [0000000000e11ea8] 0xe11ea8

--- interrupt: c00

Instruction dump:
48000ad9 60000000 7fe3fb78 4befb0f5 60000000 38210080 485fbc44 7c0802a6
485fbbcd f821ff71 ebe300c0 e93f0088 <e9290018> 2fa90000 40de001c 4bef71fd
---[ end trace 24595e2ea6e47c05 ]---

[5] Error messages in a virtual Void PPC machine:

=> Initialization complete, running stage 2...
- runit: leave stage: /etc/runit/1
- runit: enter stage: /etc/runit/2
runsvchdir: default: current.
urandom_read: 1 callbacks suppressed
random: dbus-daemon: uninitialized urandom read (12 bytes read)
udevd[2362]: starting version 3.2.10
udevd[2362]: starting eudev-3.2.10
elogind-daemon[2441]: New seat seat0.
elogind-daemon[2441]: Watching system buttons on /dev/input/event1 (QEMU 
Virtio Keyboard)
BUG: Kernel NULL pointer dereference on read at 0x00000018
Faulting instruction address: 0xc00000000075055c
Oops: Kernel access of bad area, sig: 11 [#1]
BE PAGE_SIZE=4K SMP NR_CPUS=4 QEMU e500
Modules linked in:
CPU: 0 PID: 2443 Comm: Xorg Not tainted 
5.16.0-a2_A-EON_X5000-07264-gff0700f03609-dirty #1
NIP:  c00000000075055c LR: c000000000750550 CTR: c000000000750548
REGS: c00000000a7ab7f0 TRAP: 0300   Not tainted 
(5.16.0-a2_A-EON_X5000-07264-gff0700f03609-dirty)
MSR:  0000000090029002 <CE,EE,ME>  CR: 24022288  XER: 00000000
DEAR: 0000000000000018 ESR: 0000000000000000 IRQMASK: 0
GPR00: c0000000001bd678 c00000000a7aba90 c000000001993600 c0000000028da400
GPR04: c00000000a7abc10 0000000000000001 c000000009a55800 c0000000028c2900
GPR08: c0000000017f2f88 0000000000000000 c0000000018e2418 00e8bdf0003205d4
GPR12: 0000000084082282 c000000001a68000 0000000000a53230 0000000000000000
GPR16: 0000000000000001 00000000009435d4 000000000000000b 0000000000000000
GPR20: c00000000a98cc98 c0000000028da430 0000000000000000 00000000028da400
GPR24: 000000000a036600 c00000000a036600 0000000000000000 c0000000028da400
GPR28: c000000009a55800 c00000000a98cc80 c00000000a02a210 c000000009b0b200
NIP [c00000000075055c] .virtio_gpu_poll+0x14/0x134
LR [c000000000750550] .virtio_gpu_poll+0x8/0x134
Call Trace:
[c00000000a7aba90] [c00000000a7abb10] 0xc00000000a7abb10 (unreliable)
[c00000000a7abb20] [c0000000001bd678] .ep_item_poll+0x5c/0x80
[c00000000a7abba0] [c0000000001beb5c] .do_epoll_ctl+0x604/0x878
[c00000000a7abca0] [c0000000001bee14] .__se_sys_epoll_ctl+0x44/0x8c
[c00000000a7abd50] [c00000000000b0d4] .system_call_exception+0x11c/0x148
[c00000000a7abe10] [c0000000000001f8] system_call_common+0xf0/0x210
-- interrupt: c00 at 0x24f008
NIP:  000000000024f008 LR: 000000000099e7d4 CTR: 0000000000000000
REGS: c00000000a7abe80 TRAP: 0c00   Not tainted 
(5.16.0-a2_A-EON_X5000-07264-gff0700f03609-dirty)
MSR:  000000001002f002 <CE,EE,PR,FP,ME>  CR: 46004224  XER: 00000000
IRQMASK: 0
GPR00: 00000000000000ed 00000000ffb83460 00000000f7a25f60 0000000000000003
GPR04: 0000000000000001 000000000000000b 00000000ffb83478 000000000032061c
GPR08: 0000000000e8bdf0 0000000000000000 0000000000000000 0000000000000000
GPR12: 0000000000000000 0000000000a4fff4 0000000000a53230 0000000000000000
GPR16: 0000000000000001 00000000009435d4 000000000094d848 000000000092ab90
GPR20: 0000000000a883e8 00000000fffffffd 0000000000e5edd0 0000000000e8bc60
GPR24: 0000000000904534 0000000000000001 000000000000000b 0000000000000002
GPR28: 0000000000e5f200 0000000000e8bdf0 0000000000a57b74 0000000000000002
NIP [000000000024f008] 0x24f008
LR [000000000099e7d4] 0x99e7d4

--- interrupt: c00

Instruction dump:
48000ad9 60000000 7fe3fb78 4befb0f5 60000000 38210080 485fbc44 7c0802a6
485fbbcd f821ff71 ebe300c0 e93f0088 <e9290018> 2fa90000 40de001c 4bef71fd
---[ end trace ece66d7be00861fa ]---

[6] https://i.ibb.co/SwjTyJk/Kernel-5-16-alpha1-Power-PC.png