Bug 1201632

Summary:	kernel 5.3.18-150300.59.81-default: host fails to start qemu guests
Product:	[openSUSE] openSUSE Distribution	Reporter:	Friedrich Haubensak <hsk17>
Component:	Kernel	Assignee:	openSUSE Kernel Bugs <kernel-bugs>
Status:	RESOLVED FIXED	QA Contact:	E-mail List <qa-bugs>
Severity:	Normal
Priority:	P5 - None	CC:	bpetkov, hsk17, tiwai
Version:	Leap 15.3
Target Milestone:	---
Hardware:	x86-64
OS:	openSUSE Leap 15.3
Whiteboard:
Found By:	---	Services Priority:
Business Priority:		Blocker:	---
Marketing QA Status:	---	IT Deployment:	---

Description Friedrich Haubensak 2022-07-19 08:20:01 UTC

after latest kernel patch upgrade, i.e. from kernel-default-5.3.18-150300.59.76.1 to kernel-default-5.3.18-150300.59.81.1, on host, host fails to start libvirt/qemu guests: "virsh start guest" reports guest started, but guest remains inaccessible, and the console window within virt-manager stays at a pure black screen.  reboot host to previous kernel 5.3.18-150300.59.76-default, and qemu guests start up as usual.

i observed this on hosts running leap 15.3 with all patches installed.  which further information about the case is needed?

Comment 1 Moritz Duge 2022-07-20 18:51:56 UTC

Maybe related: bug 1201664, bug 1201644 and bug 1201672

Try setting this boot parameter: spectre_v2=retpoline

If that's not working try: spectre_v2=off
But this may be bad regarding security of your system.

Comment 2 Friedrich Haubensak 2022-07-20 20:26:02 UTC

thanks for your hints.

booting 5.3.18-150300.59.81: neither spectre_v2=retpoline nor spectre_v2=off make a difference, i.e., qemu guests still do not start up.

NB, after looking at the "related bugs", as far i had access to them:  the host systems here are running stable with 59.81.  it's starting up the qemu guests that does not work, i.e., the virtual console window stays completely black and silent.  and: according to the boot log, 59.76, where qemu guest start up works, is running  with
Spectre V2 : Mitigation: Retpolines
Spectre V2 : Spectre v2 / SpectreRSB mitigation: Filling RSB on context switch

Comment 3 Friedrich Haubensak 2022-08-03 17:27:47 UTC

update:  after installing kernel-default-5.3.18-150300.59.87.1, qemu guests still do not start.

using virt-manager to display the virtual console window and then click Virtual Machine -> Run, the console window turns from grey to pure black, that's all, nothing more happens.

running "virsh start GUEST" from the HOST console, freezes HOST; have to press reset-button on HOST.

booting HOST with kernel-default-5.3.18-150300.59.76.1, qemu guests start and work well.

have now done "zypper al kernel-default", but this seems not to be a real solution...

Comment 4 Takashi Iwai 2022-08-05 08:27:10 UTC

Looks like an issue that has been already fixed in the SLE15-SP3 git branch.
Could you try the kernel in OBS Kernel:SLE15-SP3 repo?

Comment 5 Friedrich Haubensak 2022-08-05 09:29:43 UTC

added download.opensuse.org/repositories/Kernel:/SLE15-SP3/pool/ to repos, installed and booted kernel-default-5.3.18-150300.331.1.g1a841af.x86_64, and yeah, guests are starting now again.

when will the respective changes be propagated to kernel-default from repo-sle-update?

Comment 6 Takashi Iwai 2022-08-05 10:23:47 UTC

Good to hear.  Then this should be fixed in the next (upcoming) release.