emulators/qemu 2026Q3 do not work with existing images

[Ramiro Aceves <ea1abz%gmail.com@localhost>]

Hi,

After updating my NetBSD system to pkgsrc-2026Q3, QEMU no longer works correctly.

Before the update, I was using QEMU normally to run both Debian and FreeDOS VMs.

The current version is:

QEMU emulator version 11.1.1

My usual configuration uses NVMM:

qemu-system-x86_64 \
  -accel nvmm \
  -m 8G \
  -smp 4 \
  -cpu host \
  -drive file=debian.qcow2,format=qcow2 \
  -boot a \
  -nic user,model=e1000 \
  -display sdl \
  -virtfs local,id=shared_dev,path=/home/ramiro/directorio_compartido,security_model=none,mount_tag=hostshare

QEMU prints these warnings:

qemu-system-x86_64: warning: this feature conflicts with APX: CPUID[eax=07h,ecx=00h].EBX.mpx [bit 14]
qemu-system-x86_64: warning: this feature conflicts with MPX: CPUID[eax=07h,ecx=01h].EDX.apxf [bit 21]

The SDL window then opens, but its contents are corrupted/transparent: I can see the desktop through the QEMU window.

I have tried -cpu max instead of -cpu host, with the same result.

I have also tested without NVMM, using TCG and -cpu max, and the SDL display problem remains.

I tested with both a Debian VM and a FreeDOS image, so the problem does not appear to be specific to a particular guest OS or disk image.

Interestingly, using:

-display curses

does produce a QEMU display (a black screen showing "600x600 mode"), so QEMU is at least running the guest.

The available display backends reported by this QEMU are:

none
sdl
egl-headless
curses
spice-app
dbus

GTK is not available as a display backend.

Could this be a known issue with QEMU 11.1.1, SDL, or the NetBSD X11 environment? Is there anything specific that changed in pkgsrc-2026Q3 that could explain this?

Any suggestions for further diagnostics would be appreciated.

Thanks,
Ramiro