Re: port-xen/58561 (panic: kernel diagnostic assertion, "x86_read_psl() == 0" failed: file, "/home/netbsd/10/src/sys/arch/x86/x86/pmap.c", line 3581)

[Konrad Schroder <perseant%hhhh.org@localhost>]

On 1/10/2026 4:55 AM, Manuel Bouyer wrote:
> Hello,
> can you try with the attached patch ? It won't fix the problem but
> should let us know if syscall() is already called with interrupts disabled,
> or if they're disabled later

Thanks!  Unfortunately that blows up almost instantly:

Parsing config from lfs
[   1.0000000] Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
[   1.0000000]     2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 
2013,
[   1.0000000]     2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022, 
2023,
[   1.0000000]     2024, 2025, 2026
[   1.0000000]     The NetBSD Foundation, Inc.  All rights reserved.
[   1.0000000] Copyright (c) 1982, 1986, 1989, 1991, 1993
[   1.0000000]     The Regents of the University of California. All 
rights reserved.

[   1.0000000] NetBSD 11.99.4 (LFS) #0: Sat Jan 10 11:16:12 PST 2026
[   1.0000000] 
root@netbsd6:/home/src-current/obj.amd64/sys/arch/amd64/compile/LFS
[   1.0000000] total memory = 16384 MB
[   1.0000000] avail memory = 15808 MB
[   1.0000000] mainbus0 (root)
[   1.0000000] hypervisor0 at mainbus0: Xen version 4.16.0
[   1.0000000] vcpu0 at hypervisor0
[   1.0000000] vcpu0: AMD Opteron(tm) Processor 4334      , id 0x600f20
[   1.0000000] vcpu0: node 0, package 0, core 0, smt 0
[   1.0000000] vcpu1 at hypervisor0
[   1.0000000] vcpu1: AMD Opteron(tm) Processor 4334      , id 0x600f20
[   1.0000000] vcpu1: node 0, package 0, core 0, smt 0
[   1.0000000] xenbus0 at hypervisor0: Xen Virtual Bus Interface
[   1.0000000] xencons0 at hypervisor0: Xen Virtual Console Driver
[   1.0000000] WARNING: system needs entropy for security; see entropy(7)
[   1.5600517] xenbus0: can't get state for device/suspend/event-channel (2)
[   1.5700553] xbd0 at xenbus0 id 768: Xen Virtual Block Device Interface
[   1.5700553] xennet0 at xenbus0 id 0: Xen Virtual Network Interface
[   1.5700553] xennet0: backend features 0x7<IPV6-CSUM,SG,RX-COPY>
[   1.5700553] xennet0: MAC address 00:16:3e:41:a3:13
[   1.5800784] balloon0 at xenbus0 id 0: Xen Balloon driver
[   1.5800784] balloon0: current reservation: 16777216 KiB
[   1.5800784] xenbus0: can't get state for device/suspend/event-channel (2)
[   1.5800784] balloon0: current reservation: 4194304 pages => target: 
4194304 pages
[   1.5800784] xbd0: 1863 GB, 512 bytes/sect x 3907110912 sectors
[   1.5800784] xbd0: backend features 0xc<PERSISTENT,INDIRECT>
[   1.6000892] dk0 at xbd0: "fe6007c0-0019-40f8-a4ed-04267298e957", 
2097152 blocks at 2048, type: ffs
[   1.6000892] dk1 at xbd0: "57ff5f51-1beb-48c8-9eb9-045e087e6217", 
4194304 blocks at 2099200, type: swap
[   1.6000892] dk2 at xbd0: "813c4368-95e7-444a-ae58-44162b21c9c6", 
16777216 blocks at 6293504, type: ffs
[   1.6000892] dk3 at xbd0: "04353643-24a2-4aa0-b864-c5b4e4f928d8", 
8388608 blocks at 23070720, type: ffs
[   1.6000892] dk4 at xbd0: "home", 4194304 blocks at 31459328, type: ffs
[   1.6000892] dk5 at xbd0: "data", 8388608 blocks at 35653632, type: ffs
[   1.6000892] dk6 at xbd0: "data2", 16777216 blocks at 44042240, type: ffs
[   1.6000892] dk7 at xbd0: "data3", 33554432 blocks at 60819456, type: ffs
[   1.6000892] dk8 at xbd0: "data4", 67108864 blocks at 94373888, type: ffs
[   1.6000892] dk9 at xbd0: "data5", 134217728 blocks at 161482752, 
type: ffs
[   1.6000892] dk10 at xbd0: "data6", 268435456 blocks at 295700480, 
type: ffs
[   1.6000892] dk11 at xbd0: "data7", 536870912 blocks at 564135936, 
type: lfs
[   1.6000892] dk12 at xbd0: "data8", 1073741824 blocks at 1101006848, 
type: lfs
[   1.6000892] dk13 at xbd0: "data9", 1732360192 blocks at 2174748672, 
type: ffs
[   1.6000892] xenbus0: can't get state for device/suspend/event-channel (2)
[   1.6100784] WARNING: 3 errors while detecting hardware; check system log.
[   1.6100784] boot device: dk0
[   1.6100784] root on dk0 dumps on dk1
[   1.6100784] Your machine does not initialize mem_clusters; 
sparse_dumps disabled
[   1.6200746] /: replaying log to memory
[   1.6401308] root file system type: ffs
[   1.6401308] kern.module.path=/stand/amd64/11.99.4/modules
[   1.6501331] panic: copyout 14
[   1.6501331] cpu1: Begin traceback...
[   1.6501331] vpanic() at netbsd:vpanic+0x164
[   1.6501331] panic() at netbsd:panic+0x3c
[   1.7700918] start_init() at netbsd:start_init+0x4be
[   1.7700918] cpu1: End traceback...
[   1.7700918] fatal breakpoint trap in supervisor mode
[   1.7700918] trap type 1 code 0 rip 0xffffffff80230965 cs 0xe030 
rflags 0x202 cr2 0 ilevel 0 rsp 0xffffbd84c32f0d20
[   1.7700918] curlwp 0xffffbd8021aa9000 pid 1.1 lowest kstack 
0xffffbd84c32ec2c0
Stopped in pid 1.1 (init) at    netbsd:breakpoint+0x5:  leave
breakpoint() at netbsd:breakpoint+0x5
vpanic() at netbsd:vpanic+0x164
panic() at netbsd:panic+0x3c
start_init() at netbsd:start_init+0x4be
ds          0
es          1
fs          1
gs          cd0
rdi         0
rsi         2d6
rbp         ffffbd84c32f0d20
rbx         ffffffff806c0663    ostype+0x1337b
rdx         1
rcx         ffffffffffffff
rax         800000000000000
r8          0
r9          0
r10         fffffffe
r11         ffffffff806b8ad0    ostype+0xb7e8
r12         ffffbd84c32f0d68
r13         104
r14         1
r15         0
rip         ffffffff80230965    breakpoint+0x5
cs          e030
rflags      202
rsp         ffffbd84c32f0d20
ss          e02b
netbsd:breakpoint+0x5:  leave
db{1}>

It seems to me like amd64_check_psl() has some side effects that are 
messing up the registers for the call to copyout(), but I don't know 
almost anything about x86 assembly....

Thanks,

-Konrad