pkg/59154: emulators/qemu breaks with newer compatible libnvmm

[campbell+netbsd%mumble.net@localhost]

>Number:         59154
>Category:       pkg
>Synopsis:       emulators/qemu breaks with newer compatible libnvmm
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Mar 09 02:45:01 +0000 2025
>Originator:     Taylor R Campbell
>Release:        current
>Organization:
The NewNVMM Foundation
>Environment:
>Description:
We currently apply the following patch to emulators/qemu:

-    if (qemu_mach.cap.version < NVMM_KERN_VERSION) {
+    if (qemu_mach.cap.version > NVMM_USER_VERSION) {
         error_report("NVMM: Unsupported version %u", qemu_mach.cap.version);
         return -EPROGMISMATCH;
     }

This means that a qemu package built for netbsd-9, where NVMM_USER_VERSION is 1, cannot be run on netbsd-10.

I don't know what compatibility issues this was meant to address, but this breaks the standard compatibility expectations of NetBSD.

If newer libnvmm.so is incompatible, then it needs to bump the shlib major.  If it is compatible, then qemu shouldn't reject it.
>How-To-Repeat:
1. build qemu for netbsd-9
2. run it on netbsd-10
>Fix:
remove the patch