[Xen-devel] Trouble with Xen 2.0

[Jérôme Petazzoni <jp@xxxxxxxx>]

I tested Xen 2.0 and basic behaviour looks solid and stable, but 
"dynamic" features didn't work at all for me. More specifically ; with 
the precompiled build :
- saving a domain on a P4 computer was erratic (the save process was 
hung ; dom0 and the to-be-saved VM were still running fine) ; it worked 
"sometimes" (with no apparent influence of memory load, cpu load, etc). 
The logs showed the line indicating a save, but nothing more (nothing 
more than when the save succeeds)
- using the balloon interface to reduce the memory worked, but reducing 
it by a large increment caused the affected VM to crash, spitting 
repeatedly the same message over the console (I didn't have means to 
save those messages yet, sorry, but I'll try to get them asap)
- using the balloon interface to increase the memory between the initial 
value and the maximal value didn't work - sometimes it did nothing at 
all, sometimes it crashed like before
- OTOH, we could migrate a linux VM from a P4 machine to a Celeron one, 
and it kept working for a while (but /proc/cpuinfo showed wrong flags, 
so maybe some optimized code would have crashed)
now, on my old Celeron testbed, with the -testing branch compiled by 
myself :
- saving a domain seems to work, but when I restore the domain crashes 
(see attached kernel messages ; I got them after reattaching the console 
after the restore)
- xend.log and xend-debug show nothing exciting ; what should I do to 
increase verbosity here ? I tried "xend trace_start" but it didn't 
change anything - I certainly forgot something here.
- I recompiled xen0 and xenU kernels for Celeron CPU (since default 
config was P4) but it didn't change anything.
I don't know in which direction I should dig ; I could of course try 
with different Xen versions, or tweak debug flags, or try over different 
hardware ; but I don't know what would be the most clever starting point ...
regards

************ REMOTE CONSOLE: CTRL-] TO QUIT ********
invalid operand: 0000 [#1]
PREEMPT                   
Modules linked in:
CPU:    0         
EIP:    0061:[<c03003f8>]    Not tainted VLI
EFLAGS: 00010206   (2.6.9-xenU)             
EIP is at init_tsc+0x36/0xa0    
eax: c02bad10   ebx: 00018000   ecx: fbffc000   edx: 00000001
esi: 00000020   edi: c0102000   ebp: 00000000   esp: c1149f20
ds: 007b   es: 007b   ss: 0069                               
Process events/0 (pid: 3, threadinfo=c1148000 task=c0368020)
Stack: c010e4df 00000000 c0109df5 fbffc000 000001ee 00000063 c7a03000 c1148000 
       00000000 c02b9d80 00000000 c012b8d6 00000000 c1149f74 00000000 c0359278 
       c0109efd c1148000 c0359268 ffffffff ffffffff 00000001 00000000 c0118cc2 
Call Trace:                                                                    
 [<c010e4df>] time_resume+0x12/0x53
                                   
 [<c0109df5>] __do_suspend+0x1a0/0x1e1
                                      
 [<c012b8d6>] worker_thread+0x1ea/0x2e0
                                       
 [<c0109efd>] __shutdown_handler+0x0/0x48
                                         
 [<c0118cc2>] default_wake_function+0x0/0x12
                                            
 [<c0118cc2>] default_wake_function+0x0/0x12
                                            
 [<c012b6ec>] worker_thread+0x0/0x2e0
                                     
 [<c012f915>] kthread+0xa5/0xab
                               
 [<c012f870>] kthread+0x0/0xab
                              
 [<c010ed89>] kernel_thread_helper+0x5/0xb
                                          
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <f0> fb ff bf 00 00 00 
00 88 f4 ff bf 02 00 00 00 01 00 00 00 00 

************ REMOTE CONSOLE: CTRL-] TO QUIT ********
invalid operand: 0000 [#1]
PREEMPT                   
Modules linked in:
CPU:    0         
EIP:    0061:[<c03003d3>]    Not tainted VLI
EFLAGS: 00010206   (2.6.9-xenU)             
EIP is at init_tsc+0x11/0xa0    
eax: 2cac6d30   ebx: 00018000   ecx: fbffc000   edx: 00000001
esi: 00000020   edi: c0102000   ebp: 00000000   esp: c1149f1c
ds: 007b   es: 007b   ss: 0069                               
Process events/0 (pid: 3, threadinfo=c1148000 task=c0368020)
Stack: 00000246 c010e4df 00000000 c0109df5 fbffc000 000001e8 00000063 c7d82000 
       c1148000 00000000 c02b9d80 00000000 c012b8d6 00000000 c1149f74 00000000 
       c0359278 c0109efd c1148000 c0359268 ffffffff ffffffff 00000001 00000000 
Call Trace:                                                                    
 [<c010e4df>] time_resume+0x12/0x53
                                   
 [<c0109df5>] __do_suspend+0x1a0/0x1e1
                                      
 [<c012b8d6>] worker_thread+0x1ea/0x2e0
                                       
 [<c0109efd>] __shutdown_handler+0x0/0x48
                                         
 [<c0118cc2>] default_wake_function+0x0/0x12
                                            
 [<c0118cc2>] default_wake_function+0x0/0x12
                                            
 [<c012b6ec>] worker_thread+0x0/0x2e0
                                     
 [<c012f915>] kthread+0xa5/0xab
                               
 [<c012f870>] kthread+0x0/0xab
                              
 [<c010ed89>] kernel_thread_helper+0x5/0xb
                                          
Code: f8 13 30 c0 f8 13 30 c0 4c 14 30 c0 4c 14 30 c0 f4 14 30 c0 f4 14 30 c0 
9c 15 30 c0 9c 15 30 c0 80 6c dc c7 80 6c dc c7 38 29 eb <c7> 38 29 eb c7 a8 62 
dc c7 a8 62 dc c7 80 0c d3 c7 80 0c d3 c7 

************ REMOTE CONSOLE: CTRL-] TO QUIT ********
invalid operand: 0000 [#1]
PREEMPT                   
Modules linked in:
CPU:    0         
EIP:    0061:[<c03172f0>]    Not tainted VLI
EFLAGS: 00010286   (2.6.9-xenU)             
EIP is at init_tsc+0x0/0xa0     
eax: c02d6ef0   ebx: 00000020   ecx: fbffc000   edx: fbffc000
esi: c74ab140   edi: c0102000   ebp: 00000000   esp: c1169f20
ds: 007b   es: 007b   ss: 0069                               
Process events/0 (pid: 3, threadinfo=c1168000 task=c1146020)
Stack: c010ed42 00000000 c010a28e fbffc000 000001e8 00000063 c74ab000 c1168000 
       00000000 c02d6000 00000000 c012db7a 00000000 c1169f74 00000000 c11448d8 
       c010a390 c1168000 c11448c8 ffffffff ffffffff 00000001 00000000 c0119e00 
Call Trace:
 [<c010ed42>] time_resume+0x12/0x50
                                   
 [<c010a28e>] __do_suspend+0x19e/0x1e0
                                      
 [<c012db7a>] worker_thread+0x1fa/0x2f0
                                       
 [<c010a390>] __shutdown_handler+0x0/0x50
                                         
 [<c0119e00>] default_wake_function+0x0/0x20
                                            
 [<c0119e00>] default_wake_function+0x0/0x20
                                            
 [<c012d980>] worker_thread+0x0/0x2f0
                                     
 [<c013203a>] kthread+0xaa/0xb0
                               
 [<c0131f90>] kthread+0x0/0xb0
                              
 [<c010f675>] kernel_thread_helper+0x5/0x10
                                           
Code: 00 00 00 17 00 00 00 58 8f 04 08 11 00 00 00 30 8f 04 08 12 00 00 00 28 
00 00 00 13 00 00 00 08 00 00 00 fe ff ff 6f e0 8e 04 08 <ff> ff ff 6f 01 00 00 
00 f0 ff ff 6f 12 8e 04 08 00 00 00 00 00