Debugging Windows Guests on XenServer

WinDbg

WinDbg is one of a number of tools available from Microsoft that can be used for debugging Windows guests in XenServer environments.

You can get QEMU to passive-open a TCP port on dom0 for serial output and wait for a connection, this method will work if you're running on a machine with a dynamically assigned IP address:
on XenServer 6.2 or later

xe vm-param-add uuid=<uuid> param-name=platform hvm_serial=tcp::<port>,server,nodelay

on earlier versions

xe vm-param-add uuid=<uuid> param-name=other-config hvm_serial=tcp::<port>,server,nodelay

Then:

  1. Grab a copy of HW Virtual Serial Port from http://www.hw-group.com/products/hw_vsp/hw_vsp2_en.html and install it.
  2. Fire up the application and configure a COM port to point at your dom0 IP address and the <port> you specified to QEMU above). Make sure that you uncheck 'NVT Enable' in the Settings tab.
  3. Start the COM port.
  4. Configure debugging inside the guest by editing boot.ini in the usual way.
  5. Reboot the VM.
  6. Start windbg and point it at the COM port you created.
An Unofficial Method

To the best of my knowledge we have never released sockpipe.exe but this is a method some of our own developers use, it isn't supported but may be useful to developers in a debug scenario.

If you're running windbg on a machine with a statically assigned IP address then you can use the following setting to get QEMU to active-open a TCP port on your machine for serial output:

on XenServer 6.2 or later

xe vm-param-add uuid=<uuid> param-name=platform hvm_serial=tcp:<machine>:<port>

on earlier versions

xe vm-param-add uuid=<uuid> param-name=other-config hvm_serial=tcp:<machine>:<port>

Then:

  1. Run sockpipe.exe (which seems to be available here) on the machine where you want to run windbg. Run it without arguments to get help; it should be fairly obvious what's going on. For example, you could use 'sockpipe <name> <port>' (where <port> is the name number as specified to QEMU above).
  2. Fire up windbg and go ``File->Kernel Debugging'', make sure that ``Pipe'' is ticked, and enter \\.\pipe\<name> in the Port box, where <name> is the pipe name specified to sockpipe. Hit OK.
  3. Configure debugging inside the guest by editing boot.ini in the usual way.
  4. Reboot the VM.
  5. Debug as normal.

I'm told it may be a bit slow, but it mostly works although it has limitations; it will not work for SMP 64 bit or SMP Vista.

 

Further Information

 

 

 

 

About XenServer

XenServer is the leading open source virtualization platform, powered by the Xen Project hypervisor and the XAPI toolstack. It is used in the world's largest clouds and enterprises.
 
Technical support for XenServer is available from Citrix.