** Description changed:

+ 
+ SRU Justification:
+ 
+ [Impact]
+ 
  Microsoft would like to request a change to the time keeping method in
  the Azure images.
  
  We would like to request that an Azure image uses the Azure host for
  time sync by default.  This will require the use of the Chrony package.
  
  The Chrony package would need to be installed by default in all images
  and be configured to use /dev/ptp0 for timekeeping.
+ 
+ There is a request for two patches to be backported so Chrony time can
+ stay in sync before being set as the default.
+ 
+ Patches are already in the 5.8 kernel. Only needed for azure 5.4 and
+ 4.15
+ 
+ 
+ [Fix]
+ 
+ backport these two patches:
+ b46b4a8a57c3 ("hv_utils: drain the timesync packets on onchannelcallback")
+ 90b125f4cd26 ("hv_utils: return error if host timesysnc update is stale")
+ 
+ [Test Case]
+ 
+ Desired test cases:
+  - verify Chrony time can stay in sync
+  - verify caller is notified if host timesync update is stale
+  - verify all timesync packets are drained on onchannelcallback to avoid 
stale packets
+ 
+ Microsoft holds test cases for the above. They verified a 4.15 and 5.4
+ test kernels with the above patches backported to work as expected.
+ 
+ [Regression Potential]
+ 
+ Caller may get an error now if host timesync messages were not processed
+ by the guest. This wasn't getting reported to the caller before and may
+ appear to be a regression if it occurs.
+ 
+ Regression potential may also lay in still incorrectly managing timesync
+ packets on onchannelcallback.

-- 
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1896784

Title:
  Use Azure host for time keeping in all images

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux-azure/+bug/1896784/+subscriptions

-- 
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs

Reply via email to