VirtualBox 6.1.32 BUG: soft lockup - CPU#1 stuck

[Marco Sousa]

BUG: soft lockup - CPU#1 stuck for XXs!

This happen only with Virtualbox 6.1.32, doesn't happen in 6.1.30.
I try twice in 6.1.30, and twice in 6.1.32.

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Tested with: Ubuntu, Archlinux guests.
Host: Windows 10 21H2.

[scottgus1]

Start the VM from full normal shutdown, not save-state. Run until you see the problem happen, then shut down the VM from within the VM's OS if possible. If not possible, close the Virtualbox window for the VM with the Power Off option set.

Right-click the VM in the main Virtualbox window's VM list, choose Show Log. Save the far left tab's log, zip it, and post the zip file, using the forum's Upload Attachment tab.

[Marco Sousa]

..Show Log..

Added CPU halt issue log.

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VBox 6.1.30 works fine, 6.1.32 hang the CPU.

[mpack]

00:00:04.013227 CPUM: Physical host cores: 8
...
00:00:03.255196 NumCPUs <integer> = 0x0000000000000008 (8)

Why does this VM need so many cores? Are you aware that idle cores make a VM slower? The typical number of cores you assign to a VM is 2.

Leaving the host OS with 0 cores will not exactly improve matters there either, and btw VirtualBox is an app running on the host OS.

[Marco Sousa]

Why does this VM need so many cores? Are you aware that idle cores make a VM slower? The typical number of cores you assign to a VM is 2.

Thank's for the tip, but reducing to 2 cores doesn't fix it. But reducing to only 1 core, fix the issue.

The issue doesn't happen in the previous version, only in the last version.

[scottgus1]

Hyper-V is enabled. See HMR3Init: Attempting fall back to NEM (Hyper-V is active).

Apparently, something with Hyper-V or a recent glitch over Hyper-V is getting in the way now. However, the usual suspect fingering the 6.1.32 Hyper-V bug is not present:

00:04:26.226750 /TM/VirtualSync/CurrentOffset 820555 ns

There has to be close to 10 digits, you're only at 6, so that bug isn't interfering. Could be something else. The devs are working on it.

Going back to 6.1.30 is a valid workaround.

[Marco Sousa]

Hyper-V is enabled.

Hyper-V is not enabled.

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[mpack]

Hyper-v is very much enabled.

00:00:03.256294 HM: HMR3Init: Attempting fall back to NEM: VT-x is not available
00:00:03.272546 NEM: info: Found optional import WinHvPlatform.dll!WHvQueryGpaRangeDirtyBitmap.
00:00:03.272614 NEM: WHvCapabilityCodeHypervisorPresent is TRUE, so this might work...

Less argument please, more reading the faq you were given.

[Marco Sousa]

Less argument please, more reading the faq you were given.

Thanks for the FAQ, reviewing

[Marco Sousa]

Hyper-v was collaterally activated by the company.

Resume

• VirtualBox 6.1.30 CPU Core 8: Works
  VirtualBox 6.1.32 CPU Core 8: Hangs CPU #2-8
  VirtualBox 6.1.32 CPU Core 1: Works
  Downgrade to VirtualBox 6.1.30 CPU Core 8: Works
  Hyper-v Manager CPU Core: 8 Works

Thanks for the help

[AndyCot]

Known issue that 6.1.30 works with hyper-V, but 6.1.32 does not in the vast majority of cases.

BTW The latest test release is still "broken" with regards to hyper-v still not working.

[virtualjiffybag]

Just come across this after struggling with these soft lockups for a long time.
Not much to add except: this matches my experience. Soft lockups on v6.1.32, none after downgrading to v6.1.30. Hyper-V components\services are disabled, but WHvCapabilityCodeHypervisorPresent = True in VM log. Hope this can be fixed otherwise many Windows users will be stranded on old version.

[scottgus1]

Hope this can be fixed

HMR3Init: Attempting fall back to NEM (Hyper-V is active). Up to 6.1.26, things were progressing. When Windows 11 came out some tweaks were added in 6.1.28 that bugged up Windows 10 hosts with Hyper-V. The devs ate working on fixing the bugs.

Our forum guru 'fth0' has done some troubleshooting and pins down these possibilities to try (HCVI = Microsoft 'Memory Integrity'):
6.1.32 without Hyper-V
6.1.30 with Hyper-V but without HVCI
6.1.26 with Hyper-V and HVCI.

[chas4]

6.1.32 & 6.1.34 have the same bug it works fine if you downgrade to 6.1.30 (no settings are ever changed)
Windows 11 host and current Ubuntu guest VM. (attached logs)

Edit: Attached a screenshot of the error


Side note does Oracle wipe old VirtualBox forum accounts as I could not log in with my old one?

[scottgus1]

chas4, your log doesn't show the telltale time offset, but there could be another cause of the lockup. The devs' fixes for the Hyper-V bug did not make it into 6.1.34. Situation still the same as above for the present.

No, Oracle doesn't lock old forum accounts.