Bug 2167508

Summary:	[4.10] Use consistent cache mode setting logic for hotplugged disks
Product:	Container Native Virtualization (CNV)	Reporter:	Adam Litke <alitke>
Component:	Storage	Assignee:	Alexander Wels <awels>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Yan Du <yadu>
Severity:	high	Docs Contact:
Priority:	urgent
Version:	4.10.7	CC:	dholler, fdeutsch, jpeimer, rgertzbe, shaselde, yadu
Target Milestone:	---
Target Release:	4.10.8
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	4.10.8-30	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2023-08-08 10:39:20 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Adam Litke 2023-02-06 20:37:28 UTC

Description of problem:

When hot plugging a disk the cache mode is not set explicitly which can result in a default cache mode being used.  We would like to use the same logic for hot plugged disks as for conventionally attached disks which is to prefer cache=none when the underlying storage supports direct IO.  


Version-Release number of selected component (if applicable): 4.10.7


How reproducible: Always


Steps to Reproduce:
1. Create VM
2. Start VM
3. Hotplug a disk
4. Use `oc rsh` to connect to the appropriate virt-launcher Pod
5. Execute `virsh dumpxml 1`

Actual results: The xml shows a cache mode other than 'none' for the hotplug disk


Expected results: The cache mode should be set to 'none'


Additional info:

Comment 2 Yan Du 2023-03-01 05:13:47 UTC

Test on CNV-v4.10.8-37, cache mode is none


    <disk type='block' device='disk'>
      <driver name='qemu' type='raw' cache='none' error_policy='stop' io='native' discard='unmap'/>
      <source dev='/var/run/kubevirt/hotplug-disks/blank-dv' index='3'/>

Comment 3 Itamar Holder 2023-03-28 13:45:36 UTC

*** Bug 2162140 has been marked as a duplicate of this bug. ***