Linux Integration Services

Overview

Linux Integration Services is a set of drivers that enable synthetic device support in Linux VMs under Hyper-V.

The stand-alone LIS package can be installed as an upgrade in older Linux distributions with LIS built-in, but the package has not been updated since March 2020 and development is mostly stalled. If you are experiencing problems on newer distribution versions, I would recommend updating the kernel instead.

Supported Linux Distributions

RHEL 5.2 to 7.6
CentOS 5.2 to 7.6
Oracle Linux 6.4 to 7.6, with Red Hat Compatible Kernel

Features

SRIOV (for example, Azure Accelerated Networking) capability for Red Hat Enterprise Linux, CentOS, and Oracle Linux with the Red Hat Compatible Kernel versions 6.7-6.10 (64-bit only)
Updated mlx4 and mlx5 drivers for Red Hat Enterprise Linux, CentOS, and Oracle Linux with the Red Hat Compatible Kernel versions 7.3-7.4.
Linux Integration Services uses the Hyper-V TimeSync protocol to implement a Precision Time Protocol service with this time source.

See Hyper-V Guest Features for recent feature development that might not be available in the LIS package.

Usage

Validate Installation

Linux Integration Services kernel modules can be listed with the modinfo command.

# modinfo hv_vmbus
filename:    /lib/modules/2.6.32-71.el6.x86_64/extra/microsoft-hyper-v/hv_vmbus.ko
version:     4.3.5
...

This command can be repeated for all kernel modules (hv_vmbus, hv_netvsc, hv_storvsc, hv_blkvsc, and hv_utils), but only out-of-tree modules will have “version” information. See also List Out-of-Tree Modules in Linux.

To verify that all subcomponents are running in the kernel, execute the following command:

/sbin/lsmod | egrep -i "^hv|hyperv"

TimeSync PTP Service

To verify the device is the TimeSync device, check the clock name:

$ ls /sys/class/ptp
ptp0  ptp1
$ cat /sys/class/ptp/ptp0/clock_name
hyperv

To switch to the host clock when using chronyd, enable TimeSync as a source in /etc/chrony.conf:

refclock PHC /dev/ptp0 poll 3 dpoll -2 offset 0

Latest documentation for TimeSync is available at https://learn.microsoft.com/en-us/azure/virtual-machines/linux/time-sync#tools-and-resources. Note the udev rule requirement and stratum 2 configuration.

References

Linux Integration Services v4-3-5.pdf from https://www.microsoft.com/en-us/download/details.aspx?id=55106

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