Hello!
I was able to gather additional information - using small path for stock
OpenBSD 7.4/amd64 kernel to print few debug messages. Additionally I
used ACPI tools under Linux guest (under same Hyper-V in UEFI mode) to
get details on ACPI tables.
The kernel patch is this primitive:
diff -u /usr/src/sys/dev/acpi/dsdt.c{.orig,}
--- /usr/src/sys/dev/acpi/dsdt.c.orig Tue Dec 19 07:49:12 2023
+++ /usr/src/sys/dev/acpi/dsdt.c Tue Dec 19 17:59:29 2023
@@ -3742,11 +3742,23 @@
struct acpi_dsdt *p_dsdt;
struct acpi_q *entry;
- if (strlen(rootpath) > 0)
- aml_die("LoadTable: RootPathString unsupported");
+ printf("HP4\n");
+ if (strlen(rootpath) > 0){
+ aml_showvalue(parameterdata);
+ aml_die("LoadTable: RootPathString unsupported: rootpath='%s', "
+ "sign='%s', oemid='%s', oemtableid='%s', "
+ "ppath='%s'\n",
+ rootpath, signature, oemid, oemtableid, parameterpath);
+ }
if (strlen(parameterpath) > 0)
aml_die("LoadTable: ParameterPathString unsupported");
+ printf("%s:%d OK: Processing rootpath='%s', "
+ "sign='%s', oemid='%s', oemtableid='%s', "
+ "ppath='%s'\n",
+ __func__,__LINE__,
+ rootpath, signature, oemid, oemtableid, parameterpath);
+ aml_showvalue(parameterdata);
SIMPLEQ_FOREACH(entry, &sc->sc_tables, q_next) {
hdr = entry->q_table;
if (strncmp(hdr->signature, signature,
Here is what I see on console output right before panic (what is strange
that it seems to be first call to aml_loadtable() function):
acpihve0 at acpi0
HP4
0xffff800000041608 cnt:01 stk:00 integer: 0
LoadTable: RootPathString unsupported: rootpath='\', sign='OEM1',
oemid='MSFTVM', oemtableid='UARTS', ppath=''
0034 Called: \_SB_._INI
0034 Called: \_SB_._INI
panic: aml_die aml_loadtable:3751
Stopped at db_enter+0x14: popq %rbp
Using acpidump and iasl under Linux guest (same Hyper-V and also in UEFI
mode) I got these details of OEM1 table:
OEM1 @ 0x0000000000000000
0000: 4F 45 4D 31 9E 00 00 00 02 92 4D 53 46 54 56 4D OEM1......MSFTVM
0010: 55 41 52 54 53 00 00 00 01 00 00 00 4D 53 46 54 UARTS.......MSFT
0020: 00 00 00 04 10 49 07 5F 53 42 5F 5B 82 37 55 41 .....I._SB_[.7UA
0030: 52 31 08 5F 48 49 44 0C 41 D0 05 01 08 5F 44 44 R1._HID.A...._DD
0040: 4E 0D 43 4F 4D 31 00 08 5F 55 49 44 01 08 5F 43 N.COM1.._UID.._C
0050: 52 53 11 11 0A 0E 23 10 00 01 47 01 F8 03 F8 03 RS....#...G.....
0060: 01 08 79 00 5B 82 38 55 41 52 32 08 5F 48 49 44 ..y.[.8UAR2._HID
0070: 0C 41 D0 05 01 08 5F 44 44 4E 0D 43 4F 4D 32 00 .A...._DDN.COM2.
0080: 08 5F 55 49 44 0A 02 08 5F 43 52 53 11 11 0A 0E ._UID..._CRS....
0090: 23 08 00 01 47 01 F8 02 F8 02 01 08 79 00 #...G.......y.
And here is output of iasl decompiler:
/*
* Intel ACPI Component Architecture
* AML/ASL+ Disassembler version 20220331 (64-bit version)
* Copyright (c) 2000 - 2022 Intel Corporation
*
* Disassembling to symbolic ASL+ operators
*
* Disassembly of oem1.dat, Tue Dec 19 17:44:02 2023
*
* Original Table Header:
* Signature "OEM1"
* Length 0x0000009E (158)
* Revision 0x02
* Checksum 0x92
* OEM ID "MSFTVM"
* OEM Table ID "UARTS"
* OEM Revision 0x00000001 (1)
* Compiler ID "MSFT"
* Compiler Version 0x04000000 (67108864)
*/
DefinitionBlock ("", "OEM1", 2, "MSFTVM", "UARTS", 0x00000001)
{
Scope (_SB)
{
Device (UAR1)
{
Name (_HID, EisaId ("PNP0501") /* 16550A-compatible COM
Serial Port */) // _HID: Hardware ID
Name (_DDN, "COM1") // _DDN: DOS Device Name
Name (_UID, One) // _UID: Unique ID
Name (_CRS, ResourceTemplate () // _CRS: Current Resource
Settings
{
IRQ (Edge, ActiveHigh, Exclusive, )
{4}
IO (Decode16,
0x03F8, // Range Minimum
0x03F8, // Range Maximum
0x01, // Alignment
0x08, // Length
)
})
}
Device (UAR2)
{
Name (_HID, EisaId ("PNP0501") /* 16550A-compatible COM
Serial Port */) // _HID: Hardware ID
Name (_DDN, "COM2") // _DDN: DOS Device Name
Name (_UID, 0x02) // _UID: Unique ID
Name (_CRS, ResourceTemplate () // _CRS: Current Resource
Settings
{
IRQ (Edge, ActiveHigh, Exclusive, )
{3}
IO (Decode16,
0x02F8, // Range Minimum
0x02F8, // Range Maximum
0x01, // Alignment
0x08, // Length
)
})
}
}
}
Summary:
It seems (confirmed from Linux guest kernel messages) that Hyper-V
always exposes 2 serial ports (I configured Pipe only for 1st port!) in
ACPI table OEM1, which current OpenBSD kernel is unable to process for
some reason. However I'm too new to ACPI to understand what is the problem.
Please let me know if I can provide any additional details to resolve
this problem.
Best regards
--Henryk Paluch
On 12/18/23 16:51, Henryk Paluch wrote:
Hello!
While playing with GENERIC 7.4/amd64 (install74.img) under various
UEFI environments (works fine under both Proxmox/KVM and LibVirt/KVM
with i440fx machine) I had accidentally found that under Hyper-V/UEFI
kernel panics on early ACPI enumeration (originally I thought that it
was efifb0 console bug, because it was empty, but it was not that
case...).
Most important messages:
acpihve0 at acpi0
LoadTable: RootPathString unsupported
0034 Called: \_SB_._INI
0034 Called: \_SB_._INI
panic: aml_die aml_loadtable:3746
Please first let me know if OpenBSD7.4 is supposed to work under
Hyper-V in UEFI mode - it seems that there already exist all necessary
PV devices to run as Gen2, but I was unable not find official stance
on that.
Environment details:
- Host OS: Windows Server 2012R2 Standard with Hyper-V role and
Hyper-V Manager
- Guest OS: Openbsd7.4/amd64, official
https://cdn.openbsd.org/pub/OpenBSD/7.4/amd64/install74.img
- VM running as Generation 2 (UEFI, secure boot disabled - see below).
How to reproduce
----------------
1. Download official installation image from:
https://cdn.openbsd.org/pub/OpenBSD/7.4/amd64/install74.img
2. Convert it to VHDX using command like:
qemu-img convert -p -f raw -O vhdx install74.img obsd74-uefi.vhdx
3. Under Hyper-V Create Generation 2 (UEFI) VM and attach above VHDX
file as existing disk
4. disable Secure Boot under Firmware
5. before starting VM create Virtual COM port to see messages and
panic, run this command in PowerShell:
Set-VMComPort VM_NAME 1 \\.\pipe\HyperPipe
6. now start VM and press space to halt at boot> prompt
7. run Putty and select connection type `Serial` and
enter `\\.\pipe\HyperPipe` as `Serial line` name (you can keep
speed 9600 - it does not matter for pipes)
8. now back on Hyper-V in `boot>` type:
set tty com0
9. you should see now boot> prompt in Putty.
10. now boot full GENERIC kernel (to have DDB trace - therefore bsd.rd
will not help much) using this command:
boot 7.4/amd64/bsd
11. after while you should see early boot messages and panic.
boot> boot 7.4/amd64/bsd
cannot open hd0a:/etc/random.seed: No such file or directory
booting hd0a:7.4/amd64/bsd: 17163596+4137992+363792+0+1236992
[1342507+128+13178 40+1011174]=0x1959a68
entry point at 0x1001000
[ using 3672680 bytes of bsd ELF symbol table ]
Copyright (c) 1982, 1986, 1989, 1991, 1993
The Regents of the University of California. All rights
reserved.
Copyright (c) 1995-2023 OpenBSD. All rights reserved.
https://www.OpenBSD.org
OpenBSD 7.4 (GENERIC) #1336: Tue Oct 10 08:52:22 MDT 2023
dera...@amd64.openbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC
real mem = 1036947456 (988MB)
avail mem = 985939968 (940MB)
random: good seed from bootblocks
mpath0 at root
scsibus0 at mpath0: 256 targets
mainbus0 at root
bios0 at mainbus0: SMBIOS rev. 2.4 @ 0x3fdf1000 (12 entries)
bios0: vendor Microsoft Corporation version "Hyper-V UEFI Release
v1.0" date 11/ 26/2012
bios0: Microsoft Corporation Virtual Machine
efi0 at bios0: UEFI 2.3.1
efi0: EDK II rev 0x10000
acpi0 at bios0: ACPI 4.0
acpi0: sleep states S0 S5
acpi0: tables DSDT FACP APIC OEM0 WAET OEM1 SRAT BGRT
acpi0: wakeup devices
acpitimer0 at acpi0: 3579545 Hz, 32 bits
acpimadt0 at acpi0 addr 0xfee00000
ioapic0 at mainbus0: apid 1 pa 0xfec00000, version 11, 24 pins
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: AMD Athlon(tm) 64 X2 Dual Core Processor 3800+, 2000.27 MHz,
0f-4b-02
cpu0:
FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CF
LUSH,MMX,FXSR,SSE,SSE2,SSE3,CX16,HV,NXE,MMXX,FFXSR,LONG,3DNOW2,3DNOW,LAHF,CMPLEG
,AMCR8
cpu0: 64KB 64b/line 2-way D-cache, 64KB 64b/line 2-way I-cache
cpu0: 512KB 64b/line 16-way L2 cache
cpu0: smt 0, core 0, package 0
mtrr: Pentium Pro MTRR support, 8 var ranges, 88 fixed ranges
cpu0: apic clock running at 200MHz
acpihve0 at acpi0
LoadTable: RootPathString unsupported
0034 Called: \_SB_._INI
0034 Called: \_SB_._INI
panic: aml_die aml_loadtable:3746
Stopped at db_enter+0x14: popq %rbp
TID PID UID PRFLAGS PFLAGS CPU COMMAND
* 0 0 0 0x10000 0x200 0 swapper
db_enter(10,ffffffff829605c0,286,8,ffffffff81835b24,ffffffff829605c0)
at db_enter+0x14
panic(ffffffff820e210e,ffffffff820e210e,ffffffff8209b736,ea2,ffffffff824a18c2,ffffffff829605d0)
at panic+0xbc
_aml_die(ffffffff8209b736,ea2,ffffffff820c2fd5,ffffffff8209b736,ffff80000002e148,ffff80000002e158)
at _aml_die+0x3e7
aml_loadtable(ffff800000029400,ffff80000002e138,ffff80000002e148,ffff80000002e158,ffff80000002e168,ffff80000002e178)
at aml_loadtable+0x1f0
aml_parse(ffff800000041088,54,ffff800000041088,ffff800000041088,8b6e818bf00372aa,ffff800000041088)
at aml_parse+0xab5
aml_eval(0,ffff800000030288,74,0,0,0)
at aml_eval+0x301
aml_evalnode(ffff800000029400,ffff800000030208,0,0,0,ffff800000029400)
at aml_evalnode+0xb8
acpi_inidev(ffff800000030208,ffff800000029400,50be2c891493ae1a,ffffffff81db7b50,ffff800000029400,ffffffff820ce20b)
at acpi_inidev+0x6e
aml_find_node(ffff80000002be08,ffffffff820ce20b,ffffffff81db7b50,ffff800000029400,3f2da558de4bb6c9,ffffffff81db7b50)
at aml_find_node+0x84
aml_find_node(ffffffff825679c0,ffffffff820ce20b,ffffffff81db7b50,ffff800000029400,3f2da558dee5b49f,ffffffff82960a80)
at aml_find_node+0xd1
acpi_attach_common(ffff800000029400,3fdfa014,be11230416b4dc44,ffff80000002b500,ffffffff82960ca0,ffffffff824951a0)
at acpi_attach_common+0x607
config_attach(ffff80000002b500,ffffffff824a9470,ffffffff82960ca0,ffffffff81cefcc0,1be10fea7e145b1d,ffffffff82960c60)
at config_attach+0x1f4
bios_attach(ffff80000002b480,ffff80000002b500,ffffffff82960dc8,ffff80000002b480,a29e677d6a51afb1,ffff80000002b480)
at bios_attach+0x77e
config_attach(ffff80000002b480,ffffffff824a3970,ffffffff82960dc8,ffffffff819ccb70,1be10fea7e467a4f,ffffffff82960dc8)
at config_attach+0x1f4
end trace frame: 0xffffffff82960e70, count: 0
https://www.openbsd.org/ddb.html describes the minimum info required
in bug
reports. Insufficient info makes it difficult to find and fix bugs.
ddb>
ddb> show panic
*cpu0: aml_die aml_loadtable:3746
Best regards
--Henryk Paluch
