Public bug reported:

Microsoft would like to request two commits in all releases supported on
Azure.  These commits benefit SAP workloads.

These requested commits will enable support for Invariant TSC in Linux
guest VMs.  The invariant TSC means that the TSC continues at a fixed
rate regardless of the C-state or frequency of the processor (as long as
the processor remains in the ACPI S0 state).

These patches will allow guests to access the
HvSyntheticInvariantTscControl MSR and set bit 0 of this synthetic MSR,
which then enables the InvariantTSC feature.  After setting the
synthetic MSR, CPUID will enumerate support for InvariantTSC.

The following two commits enable support:
9e0333ae38ee ("clocksource/drivers/hyper-v: Set TSC clocksource as default w/ 
InvariantTSC")
dce7cd62754b ("x86/hyperv: Allow guests to enable InvariantTSC")

** Affects: linux-azure (Ubuntu)
     Importance: Undecided
         Status: New

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https://bugs.launchpad.net/bugs/1875467

Title:
  Enable Invariant TSC Support

Status in linux-azure package in Ubuntu:
  New

Bug description:
  Microsoft would like to request two commits in all releases supported
  on Azure.  These commits benefit SAP workloads.

  These requested commits will enable support for Invariant TSC in Linux
  guest VMs.  The invariant TSC means that the TSC continues at a fixed
  rate regardless of the C-state or frequency of the processor (as long
  as the processor remains in the ACPI S0 state).

  These patches will allow guests to access the
  HvSyntheticInvariantTscControl MSR and set bit 0 of this synthetic
  MSR, which then enables the InvariantTSC feature.  After setting the
  synthetic MSR, CPUID will enumerate support for InvariantTSC.

  The following two commits enable support:
  9e0333ae38ee ("clocksource/drivers/hyper-v: Set TSC clocksource as default w/ 
InvariantTSC")
  dce7cd62754b ("x86/hyperv: Allow guests to enable InvariantTSC")

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux-azure/+bug/1875467/+subscriptions

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