Hotplugging SCSI disk in QEMU VM fails
Affects | Status | Importance | Assigned to | Milestone | ||
---|---|---|---|---|---|---|
linux (Ubuntu) | Status tracked in Noble | |||||
Focal |
Fix Released
|
Undecided
|
Chengen Du | |||
Jammy |
Fix Released
|
Undecided
|
Chengen Du | |||
Lunar |
Fix Committed
|
Undecided
|
Chengen Du | |||
Mantic |
Fix Released
|
Undecided
|
Chengen Du | |||
Noble |
In Progress
|
Undecided
|
Chengen Du |
Bug Description
[Impact]
Hot-plugging SCSI disks for QEMU VMs booting with UEFI and using guest kernels >= 6.5 might be broken.
The inconsistency suggests a potential race condition.
[Fix]
Reverting the two specified commits appears to restore reliability.
==========
cc22522fd55e2 PCI: acpiphp: Use pci_assign_
40613da52b13f PCI: acpiphp: Reassign resources on bridge if necessary
==========
Upstream has resolved the issue by reverting both commits through a commit placed below.
==========
5df12742b7e3a Revert "PCI: acpiphp: Reassign resources on bridge if necessary
==========
[Test Plan]
1. Create a VM
virt-install --name scsi_test --memory 2048 --vcpus 2 --boot uefi --disk path=/home/
2. Prepare two XMLs for adding two disk devices
# cat disk_X.xml
<disk type='file' device='disk'>
<driver name='qemu' type='raw'/>
<source file='XXX.img'/>
<target dev='vdX' bus='virtio'/>
</disk>
3. Hotplug disks and check for success
virsh attach-device scsi_test disk_X.xml
[Where problems could occur]
The patch reverts two commits that previously addressed long-standing issues related to hotplugging devices with large BARs.
While this reversion may reintroduce legacy issues, it does not introduce new problems.
The associated risks are deemed low, making it worthwhile to address timing issues during the hotplugging of SCSI disks in QEMU VM.
Changed in linux (Ubuntu Focal): | |
assignee: | nobody → Chengen Du (chengendu) |
Changed in linux (Ubuntu Jammy): | |
assignee: | nobody → Chengen Du (chengendu) |
Changed in linux (Ubuntu Lunar): | |
assignee: | nobody → Chengen Du (chengendu) |
Changed in linux (Ubuntu Mantic): | |
assignee: | nobody → Chengen Du (chengendu) |
Changed in linux (Ubuntu Noble): | |
assignee: | nobody → Chengen Du (chengendu) |
description: | updated |
description: | updated |
Changed in linux (Ubuntu Focal): | |
status: | New → In Progress |
Changed in linux (Ubuntu Jammy): | |
status: | New → In Progress |
Changed in linux (Ubuntu Lunar): | |
status: | New → In Progress |
Changed in linux (Ubuntu Mantic): | |
status: | New → In Progress |
Changed in linux (Ubuntu Noble): | |
status: | New → In Progress |
Changed in linux (Ubuntu Lunar): | |
status: | In Progress → Fix Committed |
Changed in linux (Ubuntu Mantic): | |
status: | In Progress → Fix Committed |
Changed in linux (Ubuntu Jammy): | |
status: | In Progress → Fix Committed |
Changed in linux (Ubuntu Focal): | |
status: | In Progress → Fix Committed |
This bug is awaiting verification that the linux/5.4.0-171.189 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification- needed- focal-linux' to 'verification- done-focal- linux'. If the problem still exists, change the tag 'verification- needed- focal-linux' to 'verification- failed- focal-linux' .
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.
See https:/ /wiki.ubuntu. com/Testing/ EnableProposed for documentation how to enable and use -proposed. Thank you!