Bug 48013 – QEMU fails to restore savevm state

Bug 48013 - QEMU fails to restore savevm state


Summary:	QEMU fails to restore savevm state

Status:	CLOSED WONTFIX

Product:	UCS
Classification:	Unclassified
Component:	Virtualization - KVM
Version:	UCS 4.3
Hardware:	amd64 Linux

Importance:	P5 normal (vote)
Target Milestone:	---
Assigned To:	UCS maintainers
QA Contact:	UCS maintainers

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Depends on:
Blocks:
	Show dependency tree / graph

Reported:	2018-10-18 09:32 CEST by Philipp Hahn
Modified:	2023-06-28 10:46 CEST (History)
CC List:	0 users

See Also:
What kind of report is it?:	Bug Report
What type of bug is this?:	7: Crash: Bug causes crash or data loss
Who will be affected by this bug?:	1: Will affect a very few installed domains
How will those affected feel about the bug?:	2: A Pain – users won’t like this once they notice it
User Pain:	0.080
Enterprise Customer affected?:
School Customer affected?:
ISV affected?:
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Attachments
failed VM 1 (3.59 KB, text/plain) 2018-10-18 09:32 CEST, Philipp Hahn	Details
failed VM 2 (1.36 KB, text/plain) 2018-10-18 09:33 CEST, Philipp Hahn	Details
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Description Philipp Hahn

2018-10-18 09:32:41 CEST

Created attachment 9707 [details]
failed VM 1

After a host system reboot with automatic "suspend-to-disc" by libvirt-guest 2 VMs fail to re-start:

# grep savevm /var/log/libvirt/qemu/*.log
qemu-system-x86_64: Unknown savevm section or instance '0000:00:01.2/2/usb-hub' 0
qemu-system-x86_64: Unknown savevm section or instance '0000:00:06.0/ehci' 0

There also are warning regarding missing CPU features; this might related to Bug #21386, but I include it here for completeness:

Comment 1 Philipp Hahn

2018-10-18 09:33:40 CEST

Created attachment 9708 [details]
failed VM 2

Comment 2 Philipp Hahn

2018-10-18 09:49:55 CEST

Both VMs were run-time modified and USB devices were added on-the-fly; those run-time modifications are not reflected in the XML description of libvirt.
After suspend-to-disk or during migration the new Qemu process is started verbatim again and the incoming migration fails as the previous run-time modifications are not re-applied.

Run-time modifications of VM is not supported out-of-the-box with UVMM; as such I'm reducing the affectedness to 'very few domains'.

Comment 3 Philipp Hahn

2018-10-18 09:50:57 CEST

<https://wiki.qemu.org/Features/Migration/Troubleshooting#Unknown_savevm_section_or_instance_.27....27>

Comment 4 Ingo Steuwer

2021-05-14 13:46:13 CEST

This issue has been filed against UCS 4.3.

UCS 4.3 is out of maintenance and many UCS components have changed in later releases. Thus, this issue is now being closed.

If this issue still occurs in newer UCS versions, please use "Clone this bug" or reopen it and update the UCS version. In this case please provide detailed information on how this issue is affecting you.