Re: Call Trace when adding vCPU to guest

From: Thomas Gleixner
Date: Wed Apr 10 2024 - 10:57:31 EST


On Wed, Apr 10 2024 at 15:48, Thorsten Leemhuis wrote:

> On 10.04.24 15:38, Thomas Gleixner wrote:
>> On Wed, Apr 10 2024 at 09:34, Linux regression tracking (Thorsten Leemhuis) wrote:
>>> To quote from https://bugzilla.kernel.org/show_bug.cgi?id=218698
>> [...]
>>>>
>>>> When hot adding a vCPU to the guest, the guest happens Call Trace and reboot.
>>
>> https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?h=x86/urgent&id=a9025cd1c673a8d6eefc79d911075b8b452eba8f
>>
>> It'll be in rc4
>
> Ahh, splendid, thx for replying! Ciao, Thorsten
>
> #regzbot fix: a9025cd1c673a8d6eefc79d911075b8b452eb

Ooops. No!

I just read back and noticed that this is a report against some whatever
kernel:

> [ 49.782913] Call Trace:
> [ 49.783039] <TASK>
> [ 49.783147] ? __die+0x24/0x70
> [ 49.783309] ? page_fault_oops+0x82/0x150
> [ 49.783518] ? kernelmode_fixup_or_oops+0x84/0x110
> [ 49.783753] ? exc_page_fault+0xb9/0x160
> [ 49.783948] ? asm_exc_page_fault+0x26/0x30
> [ 49.784144] ? cpu_update_apic+0x1c/0x70
> [ 49.784327] generic_processor_info+0x7e/0x160
> [ 49.784541] acpi_register_lapic+0x19/0x80

# cd linus/linux
# gcur
master 2c71fdf02a95: Merge tag 'drm-fixes-2024-04-09' of https://gitlab.freedesktop.org/drm/kernel
# git grep generic_processor_info
#

generic_processor_info() was removed during the 6.9 merge window with
the topology rework before v6.9-rc1.

So the guest kernel _cannot_ be v6.9-rc2 at all.

Thanks,

tglx