Symptoms
Consider the following scenario:
-
You install the Hyper-V role on a computer that is running a 64-bit version of Windows Server 2008 or of Windows Server 2008 R2.
-
You run an application on a virtual machine (VM) that is hosted on the computer.
-
The application calls the InterlockedExchange function to set data atomically.
In this scenario, the application may stop responding or encounter various exceptions randomly.If you debug the application, the debugging information indicates that the InterlockedExchange function is incorrect.
Cause
This issue occurs because the XCHG instruction that is an InterlockedExchange primitive is not emulated atomically by the hypervisor of Hyper-V. Therefore, synchronization does not access the variables that are shared by multiple threads, and the issue that is described in the "Symptoms" section occurs.
Resolution
Hotfix information
A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix. Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site:
http://support.microsoft.com/contactus/?ws=supportNote The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.
Prerequisites
To apply this hotfix, your computer must be running one of the following operating systems:
-
Windows Server 2008 Service Pack 2 (SP2)
-
Windows Server 2008 R2
For more information about how to obtain a Windows Server 2008 service pack, click the following article number to view the article in the Microsoft Knowledge Base:
968849 How to obtain the latest service pack for Windows Server 2008
Registry information
To use the hotfix in this package, you do not have to make any changes to the registry.
Restart requirement
You must restart the computer after you apply this hotfix.
Hotfix replacement information
This hotfix does not replace a previously released hotfix.
File information
The global version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.
Windows Server 2008 file information notes
Important Windows Vista hotfixes and Windows Server 2008 hotfixes are included in the same packages. However, only "Windows Vista" is listed on the Hotfix Request page. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows Vista" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.
-
The files that apply to a specific product, SR_Level (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table.
Version
Product
SR_Level
Service branch
6.0.600 2. 22xxx
Windows Server 2008
SP2
LDR
-
The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 and for Windows Vista" section. MUM files and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintaining the state of the updated component. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.
For all supported x64-based versions of Windows Server 2008
|
File name |
File version |
File size |
Date |
Time |
Platform |
|---|---|---|---|---|---|
|
Hvax64.exe |
6.0.6002.22492 |
649,216 |
24-Sep-2010 |
13:52 |
x64 |
|
Hvboot.sys |
6.0.6002.22492 |
108,432 |
24-Sep-2010 |
18:03 |
x64 |
|
Hvix64.exe |
6.0.6002.22492 |
665,088 |
24-Sep-2010 |
13:52 |
x64 |
|
Virtualization.events.xml |
Not Applicable |
1,384 |
03-Apr-2009 |
20:56 |
Not Applicable |
Windows Server 2008 R2 file information notes
Important Windows 7 hotfixes and Windows Server 2008 R2 hotfixes are included in the same packages. However, hotfixes on the Hotfix Request page are listed under both operating systems. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows 7/Windows Server 2008 R2" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.
-
The files that apply to a specific product, milestone (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table:
Version
Product
Milestone
Service branch
6.1.760 0.20xxx
Windows Server 2008 R2
RTM
LDR
-
The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 R2 and for Windows 7" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintaining the state of the updated component. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.
For all supported x64-based versions of Windows Server 2008 R2
|
File name |
File version |
File size |
Date |
Time |
Platform |
|---|---|---|---|---|---|
|
Hvax64.exe |
6.1.7600.20888 |
634,368 |
26-Jan-2011 |
04:00 |
x64 |
|
Hvboot.sys |
6.1.7600.20888 |
117,632 |
26-Jan-2011 |
06:52 |
x64 |
|
Hvix64.exe |
6.1.7600.20888 |
686,592 |
26-Jan-2011 |
04:00 |
x64 |
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
More Information
For more information about Hyper-V architecture, visit the following Microsoft website:
General information about Hyper-V architectureFor more information about the Interlocked class, visit the following Microsoft website:
General information about the Interlocked classFor more information about the InterlockedExchange routine, visit the following Microsoft website:
General information about the InterlockedExchange routineFor more information about the xchg instruction, visit the following Microsoft website:
General information about the xchg instructionFor more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates
Additional file information
Additional file information for Windows Server 2008
Additional files for all supported x64-based versions of Windows Server 2008
|
File name |
Amd64_microsoft-hyper-v-drivers_31bf3856ad364e35_6.0.6002.22492_none_c76120a8c65f1212.manifest |
|
File version |
Not Applicable |
|
File size |
9,808 |
|
Date (UTC) |
24-Sep-2010 |
|
Time (UTC) |
18:09 |
|
Platform |
Not Applicable |
|
File name |
Update.mum |
|
File version |
Not Applicable |
|
File size |
2,143 |
|
Date (UTC) |
24-Sep-2010 |
|
Time (UTC) |
18:09 |
|
Platform |
Not Applicable |
Additional file information for Windows Server 2008 R2
Additional files for all supported x64-based versions of Windows Server 2008 R2
|
File name |
Amd64_microsoft-hyper-v-drivers-hypervisor_31bf3856ad364e35_6.1.7600.20888_none_8cd2ea4998512ec9.manifest |
|
File version |
Not Applicable |
|
File size |
4,163 |
|
Date (UTC) |
26-Jan-2011 |
|
Time (UTC) |
07:22 |
|
Platform |
Not Applicable |
|
File name |
Update.mum |
|
File version |
Not Applicable |
|
File size |
1,462 |
|
Date (UTC) |
27-Jan-2011 |
|
Time (UTC) |
00:15 |
|
Platform |
Not Applicable |
