port-amd64/59887: nvmm: running startx on an i386 guest kills the vm

[nia%pkgsrc.org@localhost]

>Number:         59887
>Category:       port-amd64
>Synopsis:       nvmm: running startx on an i386 guest kills the vm
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-amd64-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Jan 04 12:50:00 +0000 2026
>Originator:     nia
>Release:        
>Organization:
The NetBSD Foundation
>Environment:
NetBSD siphon 11.99.4 NetBSD 11.99.4 (SIPHON) #0: Sun Dec  7 01:27:19 CET 2025  nia@siphon:/encrypt/obj/sys/arch/amd64/compile/SIPHON amd64
>Description:
qemu crashes with the following:

qemu-system-i386: NVMM: Mem Assist Failed [gpa=0xa0000]
qemu-system-i386: NVMM: Failed to execute a VCPU.
[1]   Abort trap (core dumped) qemu-system-i386 -m 1g -machine q35,accel=nvmm...
>How-To-Repeat:
the command line is as follows:

qemu-system-i386 -m 1g \
	-machine q35,accel=nvmm \
	-cpu host,+invtsc \
	-smp cpus=1,maxcpus=1 \
	-display sdl \
	-object rng-random,filename=/dev/urandom,id=viornd0 \
	-device virtio-rng-pci,rng=viornd0 \
	-netdev user,id=vioif0 -device virtio-net-pci,netdev=vioif0 \
	-audiodev oss,id=oss,out.dev=/dev/audio,in.dev=/dev/audio \
	-device ac97,audiodev=oss \
	-device virtio-blk-pci,drive=hd0 \
	-drive file=netbsd-11.qcow2,if=none,id=hd0 \
	$*

>Fix: