GNU bug report logs - #58320
Hurd VM fails to boot on AMD EPYC (kvm-amd)

Previous Next

Package: guix;

Reported by: Ludovic Courtès <ludo <at> gnu.org>

Date: Wed, 5 Oct 2022 21:02:01 UTC

Severity: normal

Tags: wontfix

Done: Ludovic Courtès <ludo <at> gnu.org>

Bug is archived. No further changes may be made.

Full log


Message #8 received at 58320 <at> debbugs.gnu.org (full text, mbox):

From: Ludovic Courtès <ludo <at> gnu.org>
To: 58320 <at> debbugs.gnu.org
Cc: bug-hurd <at> gnu.org
Subject: Re: bug#58320: Hurd VM fails to boot on AMD EPYC (kvm-amd)
Date: Thu, 06 Oct 2022 15:14:13 +0200
Hi!

As suggested by Samuel on IRC, I did that early on in kdb:

  debug traps /on

such that it would stop on each trap, hopefully allowing me to see why
exec is not starting.

--8<---------------cut here---------------start------------->8---
module 0: ext2fs --multiboot-command-line=${kernel-command-line} --host-priv-por                    
t=${host-port} --device-master-port=${device-port} --exec-server-task=${exec-tas                    
k} --store-type=typed --x-xattr-translator-records ${root} $(task-create) $(task                    
-resume)                                                                                            
module 1: exec /gnu/store/99sqiayswrxxb80331pl7jxin18wv28b-hurd-0.9-1.91a5167/hu                    
rd/exec $(exec-task=task-create)                                                                    
2 multiboot modules                                                                                 
task loaded: ext2fs --multiboot-command-line=root=device:hd0s1 root=3367134b-cfb                    
d-1e90-2f38-dfd13367134b gnu.system=/gnu/store/m66ccpdzdbcd3k2fdvyaj8cgmk23lybn-                    
system gnu.load=/gnu/store/m66ccpdzdbcd3k2fdvyaj8cgmk23lybn-system/boot --host-p                    
riv-port=1 --device-master-port=2 --exec-server-task=3 --store-type=typed --x-xa                    
ttr-translator-records device:hd0s1                                                                 
task loaded: exec /gnu/store/99sqiayswrxxb80331pl7jxin18wv28b-hurd-0.9-1.91a5167                    
/hurd/exec                                                                                          
                                                                                                    
start ext2fs: Hurd server bootstrap: ext2fs[device:hd0s1] execkernel: Page fault                    
 (14), code=6                                                                                       
Stopped at  0x1000:     pushl   0x4(%ebx)                                                           
>>>>> user space <<<<<                                                                              
0x1000(bfffff24,0,0,1160b,0)                                                                        
0x11627(bfffff9c,0,0,0,2)                                                                           
0x11bb()                                                                                            
db> show all threads                                                                                
    TASK        THREADS                                                                             
  0 gnumach (f5f7cf00): 7 threads:                                                                  
              0 (f5f7be18) .W..N. 0xc11dac04                                                        
              1 (f5f7bcd0) R..O..(idle_thread_continue)                                             
              2 (f5f7bb88) .W.ON.(reaper_thread_continue) 0xc12015d4                                
              3 (f5f7ba40) .W.ON.(swapin_thread_continue) 0xc11f8e2c                                
              4 (f5f7b8f8) .W.ON.(sched_thread_continue) 0                                          
              5 (f5f7b7b0) .W.ON.(io_done_thread_continue) 0xc1201f74                               
              6 (f5f7b668) .W.ON.(net_thread_continue) 0xc11db0a8                                   
  1 ext2fs (f5f7ce40): 6 threads:                                                                   
              0 (f5f7b520) .W.O.F(mach_msg_continue) 0                                              
              1 (f5f7b290) .W.O..(mach_msg_receive_continue) 0                                      
              2 (f5f7b148) .W.O..(mach_msg_receive_continue) 0                                      
              3 (f5f7b000) .W.O..(mach_msg_continue) 0                                              
              4 (f67d4e20) .W.O..(mach_msg_receive_continue) 0                                      
              5 (f67d4cd8) .W.O..(mach_msg_continue) 0                                              
  2 exec (f5f7cd80): (f5f7b3d8) R.....                                                              
--8<---------------cut here---------------end--------------->8---

Then lots of page faults with the same stack trace, seemingly endlessly:

--8<---------------cut here---------------start------------->8---
db> c                                                                                               
kernel: Page fault (14), code=6                                                                     
Stopped at  0x1000:     pushl   0x4(%ebx)                                                           
>>>>> user space <<<<<                                                                              
0x1000(bfffff24,0,0,1160b,0)                                                                        
0x11627(bfffff9c,0,0,0,2)                                                                           
0x11bb()                                                                                            
--8<---------------cut here---------------end--------------->8---

When I “debug traps /off” and continue, the startup process hangs as
normal, and at that point ‘show all threads’ no longer shows exec.

On a “working” VM, with traps enabled early on in the same way, I don’t
see any page fault until after exec, proc, auth, etc. have been started.

Thoughts?

Ludo’.




This bug report was last modified 270 days ago.

Previous Next


GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.