HP Integrity rx2800 Kernel Debugging Guide - Page 37

3 Debugging HP Virtual Machines guests HP Virtual Machines (HPVM) is a soft partitioning and virtualization technology that provides operating system isolation with CPU allocation and shared I/O. HPVM enables a single Integrity server to emulate multiple virtual machines running distinct operating systems and environments. The Virtual Machines solution consists of two components: • A VM host (the physical system on which the virtual machines reside) • One or more virtual machines, also known as guests Virtual machines, or guests, are abstractions of real, physical machines. They are fully-loaded, operational systems, complete with operating system, system management utilities, applications, and networks, all running in the virtual machine environment that you set up for them. You boot and manage guests using the same storage media and procedures that you would if the guest operating system were running on its own dedicated physical hardware platform. HPVM Windows guest debug process HPVM Version 2.0 supports Windows kernel debugging through the host serial ports. Usually only one such port is available on low-end systems. Therefore, without an add-in serial port card, you can debug only one Windows guest at a time. To debug multiple guests on low-end systems (or even a single guest on mid-range or high-end systems, such as rx7640, rx8640, and Superdome), you need a serial port card. To enable kernel debugging for an HPVM Windows guest, complete the following steps: 1. Locate the target guest's configuration file: vmm_config.current (the host maintains all per-guest information in the /var/opt/hpvm/guests/$guest_name$ directory). 2. Open the vmm_config.current file and add the following lines to it: # Debugging uart definition uart(7,1)=/dev/ttyXX where XX is the tty belonging to the available host serial port. NOTE: The instructions above are for debugging locally over the serial port. To debug over a LAN, you would add the following line to the guest configuration file instead: tunable = 0xNNNNNNNN wdbg where NN NN NN NN is the static IP address (in hex) of the desired debug port. 3. Reboot the guest to apply the change (unless it is already off). Each guest can have only one such entry, but each guest on a given host can attach to a unique tty port to enable multiguest debugging. The procedure for physically connecting to the host machine is identical to the local debugging connection methods used on other Integrity servers (see Chapter 1). The debugger simply attaches to a given serial port on the host using a null-modem cable. Also, you must modify the Windows guest boot entry in the virtual EFI shell the same way that you do when debugging entire Integrity servers, as described in previous chapters. The only restriction is that you must use a baud rate of 38400bps. You must specify this in the NVRAM boot entry for the operating system and in the kernel debugger configuration of the debugger machine. HPVM Windows guest debug process 37