Xen Panic on CPU 0

[Billy]

Hello,

I have what seems to be a problem related to Xen (and not the ether
patch), but since ether requires an old version of Xen it didn't seem
that I should be asking the question of the Xen folks.

When booting either the compiled 3.1.0 xen or ether-patched xen I
receive an error at the Xen splash screen:

Panic on CPU 0:
Early Fatal Page Fault @.....
...
...
reboot in five seconds...
Unknown interrupt.

VT *is* enabled and based on other posts I've tried:

Disabling NX
Disabling ACPI
Disabling Hyperthreading
Disabling CPU scaling

Disabling each or all of those does not seem to help my issue. Any
other ideas would be greatly appreciated before I give up. Thanks,
Billy

I have a brand new custom machine:

Core i7 930
MSI X58 pro-e
12GB RAM

Software:
debian-504-amd64-netinst.iso
linux-image-2.6.26-2-xen-amd64

To get Xen to compile I needed to make the following change:

xen-3.1.0-src\tools\libxc\xc_core.c line 195:

Elf64_Shdr *shdrs;
if ( sheaders->num_max + SHDR_INC < sheaders->num_max )
{

to

Elf64_Shdr *shdrs;
if ( sheaders->num_max > UINT16_MAX - SHDR_INC )
{

(the fix was lifted from xen 4.0.0 source)

[Danny Quist]

Are you running a pre-existing VM or are you trying to install one from scratch? Which version of Windows are you running? Could you cat /proc/cpuinfo for us?

Danny

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[Billy]

Thanks for the reply.

I'm not even to the point at which I can start a VM. I'm new to Xen,
but I'm not even seeing the dom0 Linux boot output before getting the
error message. I get the Xen 3.1.0 splash screen with the ASCII art
and that same screen contains the CPU Panic error.

My /proc/cpuinfo:
with the following disabled:
NX
Hyperthreading
ACPI
scaling
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 26
model name : Intel(R) Core(TM) i7 CPU 930 @ 2.80GHz
stepping : 5
cpu MHz : 2807.036
cache size : 8192 KB
physical id : 0
siblings : 4
core id : 0
cpu cores : 4
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 11
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall
rdtscp lm constant_tsc arch_perfmon pebs bts rep_good pni monitor
ds_cpl vmx est tm2 ssse3 cx16 xtpr sse4_1 sse4_2 popcnt lahf_lm ida
bogomips : 5618.52
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
power management:

====== CUT OTHER 3 CPUs info ======

Without those disabled:
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 26
model name : Intel(R) Core(TM) i7 CPU 930 @ 2.80GHz
stepping : 5
cpu MHz : 1600.000
cache size : 8192 KB
physical id : 0
siblings : 8
core id : 0
cpu cores : 4
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 11
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx
rdtscp lm constant_tsc arch_perfmon pebs bts rep_good xtopology
tsc_reliable nonstop_tsc pni dtes64 monitor ds_cpl vmx est tm2 ssse3
cx16 xtpr pdcm sse4_1 sse4_2 popcnt lahf_lm ida tpr_shadow vnmi
flexpriority ept vpid
bogomips : 5614.83
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
power management:

====== CUT OTHER 7 CPUs info ======

[Billy]

As an update, I've tried the downloadable binary version of Xen 3.1.0
with the same results. I was able to compile a 3.4.X version and
everything worked fine. Must be some compatibility issue with my
hardware and the old version of Xen. Guess I'll have to find
different hardware if I want to use Ether...

[Danny Quist]

If you have the time and wouldn't mind hooking up a debugging connection via a serial port, it would be interesting to see where the crash is at. It's possible the fix could be back ported.

Danny

[Billy]

Sorry for the über slow reply. I have no problem helping to debug the
issue. I bought a null modem cable but then realized that these nice
new machines don't have RS232 anymore. Recommendations on how to
debug such an early failure without an RS232 port?

[- -]

not sure if this'd work for the host side:
http://www.synchrotech.com/products-pcie/pcie-serial-io-rs232_02.html

any one tried with an adapter? be it pci or pci-e ...

[Danny Quist]

One of those should work. If you can't get a serial card working beyond that, you can use the console. All you have to do is put these options into an entry in your menu.lst boot:

title           Developmental Ether Patched Xen
root            (hd0,0)
kernel          /xen.gz loglvl=all guest_loglvl=all dom0_mem=1G console=vga noreboot sync_console
module          /vmlinuz-2.6.26-2-xen-amd64 root=/dev/sda2 ro quiet xencons=tty2 earlyprintk=xen
module          /initrd.img-2.6.26-2-xen-amd64

Adjust accordingly for your install.

Danny