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What actually happens when you enable Hyper-V? RRS feed

  • Question

  • I've been looking at virtualization with Hyper-V for the first time. I'm curious to know what actually happens (in a very technical level) when you enable the role and reboot. I've read around but mostly what I read is that "Hyper-V" is slipped under the "management OS". Forgive me but that doesn't sound particularly descriptive?

    Regards
    Lou...

    Wednesday, July 3, 2013 9:32 AM

Answers

  • When Hyper-V role is installed, Hvboot.sys is configured to start automatically

    Hvboot.sys performs the following steps to initialize the hypervisor:

    1) Detects whether a hypervisor is already loaded and, if so, aborts launching the hypervisor.

    2) Calls a platform detection routine to determine if the processor is an Intel processor
    or an AMD processor and if it has virtualization extensions.

    3) If the processor supports virtualization extensions, Hvboot.sys loads the hypervisor image that understands
    the architecture and virtualization extensions for the specific processor. The
    processor-specific hypervisor images are:

    • AMD-V: %SystemRoot%\System32\Hvax64.exe
    • Intel VT: %SystemRoot%\System32\Hvix64.exe

    4) Invokes the hypervisor launch code on all processors known to the parent operating
    system to start the hypervisor.

    5) Initializes platform-specific per-processor structures and other hypervisor subsystems
    by using the processors’ virtualization extensions. When these operations are completed,
    the hypervisor is fully initialized.

    6) A virtual processor is created for each physical processor and the parent operating system is isolated into the parent partition.

    7) Control is returned to the parent operating system and at this point hypervisor is running ta Ring -1

    refer: http://expertpandas.com/blog/index.php/hyper-v-hypervisor-boot-process/

    Thanks.


    KailashC

    • Proposed as answer by MBSNL Wednesday, July 3, 2013 9:38 PM
    • Marked as answer by Yan Li_Moderator Friday, July 5, 2013 6:04 AM
    Wednesday, July 3, 2013 9:55 AM
  • another good link to understand architecture & terminology in detail is http://blogs.msdn.com/b/virtual_pc_guy/archive/2008/02/25/hyper-v-terminology.aspx

    Thanks.


    KailashC

    Wednesday, July 3, 2013 10:01 AM

All replies

  • When Hyper-V role is installed, Hvboot.sys is configured to start automatically

    Hvboot.sys performs the following steps to initialize the hypervisor:

    1) Detects whether a hypervisor is already loaded and, if so, aborts launching the hypervisor.

    2) Calls a platform detection routine to determine if the processor is an Intel processor
    or an AMD processor and if it has virtualization extensions.

    3) If the processor supports virtualization extensions, Hvboot.sys loads the hypervisor image that understands
    the architecture and virtualization extensions for the specific processor. The
    processor-specific hypervisor images are:

    • AMD-V: %SystemRoot%\System32\Hvax64.exe
    • Intel VT: %SystemRoot%\System32\Hvix64.exe

    4) Invokes the hypervisor launch code on all processors known to the parent operating
    system to start the hypervisor.

    5) Initializes platform-specific per-processor structures and other hypervisor subsystems
    by using the processors’ virtualization extensions. When these operations are completed,
    the hypervisor is fully initialized.

    6) A virtual processor is created for each physical processor and the parent operating system is isolated into the parent partition.

    7) Control is returned to the parent operating system and at this point hypervisor is running ta Ring -1

    refer: http://expertpandas.com/blog/index.php/hyper-v-hypervisor-boot-process/

    Thanks.


    KailashC

    • Proposed as answer by MBSNL Wednesday, July 3, 2013 9:38 PM
    • Marked as answer by Yan Li_Moderator Friday, July 5, 2013 6:04 AM
    Wednesday, July 3, 2013 9:55 AM
  • another good link to understand architecture & terminology in detail is http://blogs.msdn.com/b/virtual_pc_guy/archive/2008/02/25/hyper-v-terminology.aspx

    Thanks.


    KailashC

    Wednesday, July 3, 2013 10:01 AM
  • Thanks for that - excellent description... :-)
    Wednesday, July 3, 2013 2:31 PM