Call unstick_channels to mitigate the lost synic issue #376

juantian8seattle · 2024-11-21T21:38:00Z

This PR addresses an issue where the synic event was lost during the save process. To mitigate this issue during the restore process, we have introduced a new field lost_synic_bug_fixed in the SavedState structure. The lost_synic_bug_fixed field will indicate whether the issue was fixed in save code path. During the restore process, we check if the field is not set then unstick_channels() function is called to mitigate the issue.

In below kmsg traces, yellow line shows we check the field to see if need call unstick_channels and green line shows we did hit the issue where the rings were not empty and need signal the guest:

… not in before servicing

vm/devices/vmbus/vmbus_server/src/lib.rs

call unstick_channels to mitigate the lost synic issue if the fix was…

fcbdc95

… not in before servicing

juantian8seattle requested a review from a team as a code owner November 21, 2024 21:38

juantian8seattle self-assigned this Nov 21, 2024