Using the VixCOM library « The Tranxition Developer Blog

Using the VixCOM library

I recently had a requirement to automate testing of kernel mode drivers under various operating systems. We also needed the automated testing to be part of the MSBuild process, so we needed to be able to control the tests by either using a .NET component or a COM Control. Obviously we couldn’t use the build machine to run any of the tests because if a kernel mode driver fails, it usually kills the system with a BSOD(blue screen of death) and that would greatly interfere with the whole build process.

I took a look at Microsoft’s Virtual Server, but I have always thought it was not that intuitive. Since we already use the VMWare Workstation solution for various development tasks, the Free VMWare Server was the ideal choice. VMWare has a few SDK alternatives that allow you to automate VMWare Workstation and Server. The Vix API allows us to control VMWare Server and load virtual machines, revert to last snapshots, copy files onto the VM, and run programs in the virtual machines. The VixCOM COM component will allow us to easily use the API’s within our C# project.

Once you’ve installed the Vix API, you can add the VixCOM COM reference to your project by selecting the “VixCOM 1.0 Type Library” Component.

The lack of documentation and practical samples seemed to be the biggest problem with the VIX API, so I created a wrapper class, VixWrapper.cs in C# to handle most of the APIs.

VixWrapper.cs listing

using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;

using VixCOM;

namespace Tranxition.BuildTasks
{
    class VixWrapper
    {
        VixCOM.IVixLib vixLib = null;

        ulong m_vixError;
        VixCOM.IHost m_hostHandle = null;
        VixCOM.IVM m_vmHandle = null;

        public ulong GetError()
        {
            return m_vixError;
        }

        public VixWrapper()
        {
            try
            {
                vixLib = new VixCOM.VixLibClass();
            }
            catch (COMException comExc)
            {
                System.Diagnostics.Trace.WriteLine(comExc.Message + “\n”);
                throw;
            }
        }

        /// <summary>
        /// Creates a host handle
        /// </summary>
        /// <returns>true if succeeded, otherwise false</returns>
        public bool Connect(string hostName, string userName, string password)
        {
            int hostType = string.IsNullOrEmpty(hostName) ?
                VixCOM.Constants.VIX_SERVICEPROVIDER_VMWARE_WORKSTATION :
                VixCOM.Constants.VIX_SERVICEPROVIDER_VMWARE_SERVER;

int vixVersion = VixCOM.Constants.VIX_API_VERSION;

vixVersion = 1; // Bugfix: http://communities.vmware.com/message/649925#649925

VixCOM.IJob jobHandle = vixLib.Connect(vixVersion,
hostType, hostName, 0, userName, password, 0, null, null);

int[] propertyIds = new int[1] { VixCOM.Constants.VIX_PROPERTY_JOB_RESULT_HANDLE };
object results = new object();

m_vixError = jobHandle.Wait(propertyIds, ref results);

            if (m_vixError == VixCOM.Constants.VIX_OK)
            {
                object[] objectArray = (object[])results;
                m_hostHandle = (VixCOM.IHost)objectArray[0];
                return true;
            }

return false;
}

        /// <summary>
        /// Opens the virtual machine specified in vmxFilePath
        /// </summary>
        /// <param name=”vmxFilePath”>The virtual machine vmx file to open</param>
        /// <returns>true if succeeded, otherwise false</returns>
        public bool Open(string vmxFilePath)
        {
            IJob jobHandle = m_hostHandle.OpenVM(vmxFilePath, null);

int[] propertyIds = new int[1] { VixCOM.Constants.VIX_PROPERTY_JOB_RESULT_HANDLE };
object results = new object();

m_vixError = jobHandle.Wait(propertyIds, ref results);

            if (m_vixError == VixCOM.Constants.VIX_OK)
            {
                object[] objectArray = (object[])results;
                m_vmHandle = (VixCOM.IVM)objectArray[0];
                return true;
            }

return false;
}

        /// <summary>
        /// Power on the virtual machine
        /// </summary>
        /// <returns>true if succeeded, otherwise false</returns>
        public bool PowerOn()
        {
            IJob jobHandle = m_vmHandle.PowerOn(VixCOM.Constants.VIX_VMPOWEROP_LAUNCH_GUI,
                null, null);
            m_vixError = jobHandle.WaitWithoutResults();

            if (m_vixError == VixCOM.Constants.VIX_OK)
            {
                //
                // Wait until guest is completely booted.
                //
                jobHandle = m_vmHandle.WaitForToolsInGuest(300, null);

m_vixError = jobHandle.WaitWithoutResults();
}