APPLIED: [PATCH 0/6 v2][BFGH][linux] Fix kdump failures

[Tim Gardner]

Applied to b:azure-4.15-next fgh:azure-next. Thanks.

Still needs to be applied to the master kernels next SRU cycle

-rtg

On 5/6/21 4:30 PM, Tim Gardner wrote:
> v2 - proper subject lines for the various patches.
> 
> BugLink: https://bugs.launchpad.net/bugs/1927518
> 
> [Impact]
> 
> Microsoft has reported that a customer is not able to acquire a kdump
> when a guest crashes.
> 
> SF: #00310145
> https://canonical.lightning.force.com/lightning/r/Case/5004K000005pZNNQA2
> 
> The following 3 patches fix the issue. Patch #1 solves a problem where the
> “Unable to send packet via vmbus” message is output continuously. But with
> that problem fixed, the second problem can occur where the kdump kernel
> panics due to receiving an unexpected VMbus UNLOAD complete message.
> 
> Patch #2 prevents the UNLOAD complete message from ever occurring in the
> kdump kernel. But if the UNLOAD complete message does occur at some
> unexpected time, Patch #3 prevents it from causing a panic.
> 
> [Test Plan]
> 
> Cause a guest kernel crash and acquire a kdump.
> 
> [Where problems could occur]
> 
> The increased Hyper-V timeout could have side effects.
> 
> [Other Info]
> 
> If these patches are deemed unsuitable for master, then I would at least like to have them
> applied to fgh:linux-azure and bionic:linux-azure-4.15
> 
> The Bionic patches are also all clean cherry-picks, but 'git am' would not apply
> the third of the FGH patches. There is likely some option to 'git am' that I'm
> too lazy to find or remember.
> 
> 

-- 
-----------
Tim Gardner
Canonical, Inc