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VmHostAssignableDevice of a PCI device to a 32-bit Guest OS RRS feed

  • Question

  • Hi,

    Whenever I try to set over PCI-passhtru a PCI device to a 32 bits Guest VM (Linux Guest, Windows 7 Guest), if the VM is a 32 bit instance, the device is not enumerated and it does not show up into the guest.

    For the same hyper-v configuration, but running a 64 bits Guest VM (Linu, Windows 10), then the device is enumerated and the drivers of the VMs can probe it.

    Please, why does Hyper-v cares if the VM is 32 bits or 64s for PCI Passthru ? Are they are tuning with Hyper-v PCI enumartion when one needs to leverage PCI-passhtru ?

    thank you,

    Tuesday, June 25, 2019 5:17 PM

All replies

  • Hi ,

    How did you pass through a PCI device to VM? Did you use DDA? 

    As far as I know, DDA allows a specific physical PCIe device installed on the host system to be directly and exclusively controlled by a guest virtual machine (VM).

    DDA is supported for following guests:

    Windows 10, Windows Server 2019, Windows Server 2016, Windows Server 2012r2 with KB 3133690 applied, and various distributions of the Linux OS.

    In order to make full use of all benefits that Hyper-V provides, it is best to use Hyper-V-specific devices for Linux and FreeBSD. The collection of drivers that are required to run Hyper-V-specific devices are known as Linux Integration Services (LIS) or FreeBSD Integration Services (BIS).

    LIS has been added to the Linux kernel and is updated for new releases. But Linux distributions based on older kernels may not have the latest enhancements or fixes.

    For your reference:

    Plan for Deploying Devices using Discrete Device Assignment

    Supported Linux and FreeBSD virtual machines for Hyper-V on Windows

    Best Regards,

    Candy


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    Wednesday, June 26, 2019 3:12 AM
  • Hi ,

    Just want to confirm the current situations.

    Please feel free to let us know if you need further assistance.                   

    Best Regards,

    Candy


    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com   

    Friday, June 28, 2019 9:00 AM
  • Hi ,

    You could mark the useful reply as answer if you want to end this thread up.

    If there is anything else we can do for you, please feel free to post in the forum.

    Best Regards,

    Candy


    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com   

    Monday, July 1, 2019 3:17 AM