[PATCH 0/1][focal/jammy/kinetic/lunar linux] Disable hv-kvp-daemon if /dev/vmbus/hv_kvp is not present

[Tim Gardner]

On 6/26/23 03:41, Stefan Bader wrote:
> On 23.06.23 15:43, Tim Gardner wrote:
>> BugLink: https://bugs.launchpad.net/bugs/2024900
>>
>> SRU Justification
>>
>> [Impact]
>>
>> If the hv-kvp daemon is started and the vmbus is not present it will 
>> just exit with an error:
>> https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/mantic/tree/tools/hv/hv_kvp_daemon.c#n1424
>>
>> Thus, it would make sense to add 
>> "ConditionPathExists=/dev/vmbus/hv_kvp" in
>> linux-cloud-tools-common.hv-kvp-daemon.service to prevent systemd from 
>> starting
>> the daemon if the device is not there.
>>
>> [Test Plan]
>>
>> Start an Azure cloud instance and check for /dev/vmbus/hv_kvp and that 
>> hv-kvp-daemon is running.
>> Start a non-Azure cloud instance and check that hv-kvp-daemon is not 
>> running.
>>
>> [Regression potential]
>>
>> Its possible that kv-hvp-daemon is not started when it should be.
>>
>>
>>
> 
> It is a bit confusing to see this submitted for the primary kernels 
> while it sounds like this is something for the azure cloud kernels. 
> Maybe some explanation would help here. I guess this goes back to times 
> when there were no specific cloud kernels.
> 

I think some folks still use the generic kernel on Azure, though I admit 
I haven't tried it in awhile. That is why I thought this patch would be 
appropriate for generic. As far as I can tell it will only impact 
kernels running on Azure.

rtg

-- 
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Tim Gardner
Canonical, Inc