port-i386/55082: GENERIC_PAE kernel panic

[acruhl%gmail.com@localhost]

>Number:         55082
>Category:       port-i386
>Synopsis:       GENERIC_PAE kernel panic
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-i386-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Mar 19 02:00:00 +0000 2020
>Originator:     Andy Ruhl
>Release:        netbsd-9 with source from about 2020-03-12
>Organization:
>Environment:
It panics at boot time, can't do this
>Description:
I had been using GENERIC_PAE in netbsd-8 with no problems. I upgraded to netbsd-9 from a snapshot at nyftp.netbsd.org, then got netbsd-9 source and compiled a GENERIC_PAE kernel. This is the same thing I had been doing in netbsd-8. With netbsd-9, the GENERIC_PAE kernel panics. The GENERIC kernel does not.

Here are the last messages before the panic:

uvm_fault(0xc1385da0, 0, 1) -> 0xe
fatal page fault in supervisor mode
trap type 6 code 0 eip 0xc0a6eec8 cs 0x0 eflags 0x10202 cr2 0 ilevel 0
esp 0xe36eadac
curlwp 0xca8763c0 pid 0 lid 70 lowest kstack 0xe36e92c0
kernel: supervisor trap page fault, code=0
Stopped in pid 0.70 (system) at netbsd:intel_ring_initialized+0x39:
 movl 0(%eax),%eax
db{0}>

Here is the bt output (typed from screenshot, hopefully no typos):

db{0}> bt
intel_ring_initialized(ca966584,c0caa054,ca9b56a8,14,ca966074,ca966000,ca9b3004,ca96600,e36eadd8,c0a47a88) at netbsd:intel_ring_initialized+0x39
direct_interrupts_to_host(ca9b3038,7,ca966500,0,0,ca966000,ca966000,ffffffea,ca96600,e36eaefc) at netbsd:direct_interrupts_to_host+0x1f
intel_guc_ucode_fini(ca9b3004,3,0,1,0,3,6,1,ca9b3400,c089b94c) at netbsd:intel_guc_ucode_fini+0x19
i915_driver_load(ca9b3004,c0f4dca0,ca83f964,ca9b3004,e36eaf50,c05bf88c,ca9b3004,c0f4dca0,5,ca83f974) at netbsd:i915_driver_load+0x1300
drm_dev_register(ca9b3004,c0f4dca0,5,ca83f974,ca83f964,ca83f96c,ca83f974,ca9b300,4,24,6) at netbsd:drm_dev_register+0x80
drm_pci_attach(ca729c40,ca72f044,ca72f090,c128ee20,c0f4dca0,ca72f08c,ca8763c0,ca72f090,c0f4dca0,ca67afd0) at netbsd:drm_pci_attach+0x1ab
i915drmkms_attach_real(ca729c40,ca8763c0,ca8763c0,0,c0100461,ca8763c0,1554000,157a000,0,c010044c) at netbsd:i915drmkms_attach_real+0x94
config_mountroot_thread(ca8763c0,1554000,157a000,0,c010044c,0,0,0,0,0) at netbsd:config_mountroot_thread+0x2b
>How-To-Repeat:
Compile a netbsd-9 GENERIC_PAE kernel for i386 and try to boot it. I have only tried 1 machine so not sure if it is something specific to this machine.
>Fix:
Use the GENERIC kernel as a workaround for now.