Re: Testing status of HVM (Intel VT) on 64bit XEN unstable c/s 11616

[Ed Smith <esmith@virtualiron.com>]

Steven Hand wrote:
> Hi Ed, 
> 
> any chance you can test with debug=y ? The back-traces aren't 
> really very useful otherwise. 
> 

These are automated builds and tests that run each night.  We don't
normally build a debug XEN as we try and test the bits a customer
would run.  If these backtraces are useful in the release build how
will we diagnose crashes on a customer's site?

> It'd also be good to know what the h/w platform is - AMD or Intel. 

This hardware and guest information is in the test report but I've
added it here as well.  Also I tried booting the guests with/without
the kernarg noapic, no difference.  Did you need more guest config
information that this? I can send you the actual config if you like
but these are the key settings.

Test Configuration:
Dell Precision WorkStation 380, Dual Core, 2GB, 3 SATA (Intel VT)
64bit XEN Hypervisor on a RHEL4U2 64bit root (/dev/sda)
32bit fully virtualized (HVM) guest RHEL4U2 256MB (/dev/sdb)
       pae=1(smp) pae=0(up), acpi=1, apic=1
       kernargs noapic
64bit fully virtualized (HVM) guest RHEL4U2 256MB (/dev/sdc)
       pae=1, acpi=1, apic=1
       kernargs noapic

> 
>> Summary:
>> Changeset 11616
>> - NEW: 32bit SMP HVM Guests hang on boot:
>>   "Uncompressing Linux... OK booting the kernel" (failure.6)
> 
> By '32bit' do you mean PAE? What guest is this? What's the guest
> config? I cannot reproduce this myself on 11616... 

RedHat 4 SMP kernels as shipped are PAE, while their UP kernels
are non-PAE.  The appropriate setting is used in HVM config
depending on which kernel I'm booting.

> 
> 
>> - NEW: 64bit UP and SMP guests crash domain on boot:
>>   domain_crash_sync called from vmx.c:2268 (failure.5)
> 
> This looks like the same bug to me, also cannot repro. 
> Once more, guest + guest config info would be useful. 

Hardware and guest information is in the report, see above.

> 
> 
>>  2. XEN crash on an xm destroy of a dead guest
>>     32bit SMP HVM guest:
>>     Fatal page fault - put_page_from_l1e+0x85/0x140
> 
> Hmm - when you say "GUEST CRASHED IN GUEST CONSOLE", what actually
> happens? Can you post the output? Have you seen this post 11486, or 
> has it gone away? 

I did not have the guest configured for serial console so the stack
traces scrolled by on the guests VGA console.  If I can reproduce this
I'll capture the serial console output and post it.  I did not reproduce
this yesterday on c/s 11600.

> 
> Can you let us know what guest and guest config you are using? 

In report.

> 
> Testing with a debug build of Xen will also help. 
> 
> 
>>  3. XEN crash running ltp "mtest01 -p80" on 32bit SMP HVM guest:
>>     BUG at multi.c:2864 from sh_page_fault__shadow_3_guest_3
> 
> This is probably the same as #2, just taking a different path through
> Xen. Have you seen this post 11486, or has it gone away? 
> 
> [Again: guest, guest config, debug xen] 

Again in report.  This particular crash was not reproduced yesterday on
c/s 11600.

> 
>>  4. XEN crash running ltp "mtest01 -p80" on 32bit SMP HVM guest:
>>     BUG at multi.c:3958 from sh_clear_shadow_entry__shadow_3_guest_3
> 
> May be related to #2 and #3. 

This bug was reproduced on c/s 11600.

> 
> [Again: guest, guest config, debug xen] 

Again in report.

> 
> 
> 
> cheers,
> 
> S.
> 
>

Thanks,
Ed