kern/60221: nvmm does not match expectations of Linux ioapic detection code

["rjs%fdy2.co.uk@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

>Number:         60221
>Category:       kern
>Synopsis:       nvmm does not match expectations of Linux ioapic detection code
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri May 01 13:50:00 +0000 2026
>Originator:     Robert Swindells
>Release:        NetBSD 11.99.5 2026-05-01
>Organization:
	NetBSD
>Environment:
	
	
System: NetBSD ren.fdy2.co.uk 11.99.5 NetBSD 11.99.5 (REN) #1: Fri May 1 11:11:27 BST 2026 rjs%ren.fdy2.co.uk@localhost:/u0/src/sys/arch/amd64/compile/REN amd64
Architecture: x86_64
Machine: amd64
>Description:
	Recent linux versions contain a function check_timer() that is
	run at boot time to verify that the IO APIC is working correctly.

	The tests fail when running Linux under qemu with nvmm acceleration
	and the Linux kernel panics.

	Booting NetBSD in a virtual machine seems to detect the ioapic.
>How-To-Repeat:
	Try to run recent linux using qemu -accel nvmm
>Fix:
	Would be good.

>Unformatted: