Custom Hypercall in XEN - virtualization

I was playing around with XEN kernel and I wanted to implement a custom hypercall on XEN. I added an entry in entry.S, defined a constant in xen.h, declared a prototype in hypercall.h and made a new body too in kernel.c as written in this blog.
I am getting an error saying that function is not implemented when i try to execute the hypercall. Iam using Ubuntu 14.04 LTS and Xen 4.7. Any idea why is the function not being implemented though I have clearly tried doing it.

Did you try in Privcmd (as of mentioned in that blog)?
I recently try it in Xen 4.6.1 and became runable with no problem. it may be because of wrong invoking method or less of privileged. have you ever solved it?


WinLockDLL.dll functions in Windows7

I'm running an app for testing students, which prevents them from doing anything but the test.
Naturally, the app blocks them from closing it, and blocks them from running the task manager (among other things):
private static extern int CtrlAltDel_Enable_Disable(bool bEnableDisable);
private void Restrict(bool enabled)
The dll contains other functions I use, such as hiding the taskbar and the desktop.
Until recently, the students all had WindowsXP, and it worked.
Recently the students have all upgraded to Windows7, and it stopped working.
During debugging, I've found that Windows7 simply doesn't HAVE WinLockDLL.dll, so I copied the dll to one of the W7 computers and gave the app a try.
This time it found the dll and raised no errors, but the function simply had no effect.
So, does anyone know of an alternative in Windows7?
The closest thing I found was this, in which someone posted that:
All the functions you used in the example crash on Windows 7 unless you change the call to DLL_CALL_STDCALL
"Calling STDCALL" doesn't help, since that is exactly what DllImport does by default.
I've read of alternatives for blocking ctrl-alt-delete, such as canceling the ctrl key or blocking the taskmanager via registry or GPO, but I much prefer a simply alternative for WinLockDLL.dll, which contains several functions I use.
Thanks in advance!
For anyone that finds this in the future. I am creating a library to replace WinLock.dll for Windows 7. The source can be found here.
Win7Lock Github

Configure Apache Hive for LLAP without using slider

There's a new feature in hive called LLAP. During the investigation I've found out that it's quite difficult to configure LLAP so there's a component called Apache Slider that will configure it. Still I couldn't find any documentation for manual configuration without Slider.
Take a look at this documentation.
[Updated] it seems like the above page was removed by Hortonworks
The only option I can suggested now is

RedHawk IDE cannot connect to domain manager after launch attempt

I am attempting to test my first waveform built with RedHawk running on CentOS. It has two components and they run ok in the sandbox, but when I attempt to launch a domain in order to test it as a waveform, it fails with a CORBA_COMM:Failure vmcid SUN minor code 201. If I turn debug level up to DEBUG or TRACE I can see that the domain manager starts and binds to the Naming Service and the last line in the console is
Starting ORB!
then a popup giving the CORBA_COMM failure. I can see the DomainManager proc running with ps and using nameclt I can see the domain registered in the NamingService, but the CORBA Name Service tab in the IDE does NOT show it (both nameclt and the IDE show EventChannelFactory). The IOR returned by nameclt and the one listed in the IDE console DEBUG line differ (shouldn't they match?).
This is somewhat similar to a question asked jerhil Jan 9 although he was using Fedora 20, but there has never been an answer to that question.
I had the same problem. What seemed to be wrong for me was a fix I used from This stackoverflow article Sandbox not Appearing in SCA Explorer. If you had this same issue and used this fix I would suggest trying one of these fixes instead as they both worked for me.
1.) (This is probably the better method to try)
Follow the answer given to this question: Cannot Change Component Property Values
2.)If that didn't work try:
a.)Uncomment the line in eclipse.ini suggested in the linked postb.)Comment out the line directly below it:-Dorg.omg.CORBA.ORBSingletonClass=org.jacorb.orb.ORB
After doing either of these solutions and restarting the IDE I was then able to launch a domain manager from the IDE.
Hopefully this helps
Try restarting the omniNames and omniEvents using this guide:
Most of the time hard reset works over soft reset. If that doesn't work, try running the simple waveform mentioned in the redhawk documentation. If you can run that fine, then it's probably the component itself that's causing the issue.

MySQL Connector/NET - support for transactions under Mono

Does anyone know how to get MySQL transactions working under Mono?
I'm using MySQL Connector/NET (via Subsonic 3) and it works perfectly under Microsoft .NET. Recently however I tried running the same site under Mono on Ubuntu and it almost works - except I can't seem to get transactions working.
Reading around the Mono/MySQL sites it's not exactly clear what is and isn't supported.
The original problem is a NotImplementedExcetion with call stack like this:
[System.NotImplementedException]: The requested feature is not implemented.
at MySql.Data.MySqlClient.MySqlConnection.EnlistTransaction (System.Transactions.Transaction) <0x00181>
at MySql.Data.MySqlClient.MySqlConnection.Open () <0x00381>
at SubSonic.DataProviders.DbDataProvider.CreateConnection (string) <0x00059>
at SubSonic.DataProviders.DbDataProvider.CreateConnection () <0x00015>
There's a few mentions of this on the MySQL site which seem to point to Mono not supporting the required infrastructure to make transactions work. There's also a comment that transactions work fine when using CommittableTransaction rather than TransactionScope. So I tried that, but got the same exception.
Another comment on the MySQL site suggested rebuilding the MySQL data provider with the MONO build option. Which I tried and the site now works, but transactions aren't being used - they've been simply disabled. Really?
I find it hard to believe that transactions can't be made to work in this environment, but can't find a working example.
Mono 2.6.7, MySQL Connection/NET 6.3.4, Subsonic 3, Ubuntu 10.10
Figured it out. It's TransactionScope that doesn't seem to work. Reverting back to DbConnection.BeginTransaction works fine. I've written up how to do it under Subsonic here:
I also had this problem with mono v.2.10.9 and mysqlconnector v. 6.6.5 and 6.7.2-Beta and I was unable to find a solution for this problem but now I figured it out.
First I took the sources of mysqlconnector and added them into my project folder. Thought it would work if I compile the connector directly with mono but it doesn't.
Then I stepped trough the code and I found that there are the following lines of code at line 530 in the file Connection.cs of the MySql.Data project:
#if !MONO && !CF && !RT
Console.WriteLine("### Should not be here... ###");
if (Transaction.Current != null && Settings.AutoEnlist)
The Console.WriteLine was added by me to try if it will also appear if I run my Application with mono and it appeared. So I commented this lines out and after that everything was working at this moment.
The real solution however should not be to comment out some lines of code.
For solving this you have to define the 'MONO' symbol.
If you are using MonoDevelop just right click on the project MySql.Data and select the compiler section. There you will find a textbox with the label 'define symbols' or something similar. Simply add the new symbol 'MONO' into this textbox.

Flash Player 10,0,32,18 upgrade breaks my LocalConnections. Any ideas?

For some reason everyone who upgrades their Flash Player to the latest version (10,0,32,18) immediately start having problems with my application. According to my logging, LocalConnection.connect() is failing. The only documented reason for this is that another SWF running on the machine is using that name. However, I know nothing else is using that name (I generate a unique name every time, AND no other SWFs are running on my machine).
The code worked perfectly fine before the update, but after the update it breaks every single time. However, there's no information that I can find that suggests there were any planned changes to the way LocalConnection works that would be causing this.
It looks like LocalConnection was changed for this update, but only for the Mac, and in a way that should be fully backwards compatible (the issues I'm seeing are on Windows. Haven't had a mac to test it on).
Has anyone else seen this? So far I haven't been able to reproduce it in simple test cases, but it's 100% consistent in my application.
Any ideas on what the problem might be?
Found a fix.
In my code I had a class that extended LocalConnection which would connect on construction. In its constructor it called:
Changing this to:
fixed the problem (My class didn't override the connect method).
I'm glad this fixed it, but I'm a bit concerned that this was the fix. Since my class didn't override the connect() method I would expect super.connect() and this.connect() to be equivalent. And up until the latest update of the Flash player they were. The fact that this broke implies to me that a bug was introduced somewhere in the player's inheritance handling. Worrysome.
Thanks to for suggesting the fix.