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vnc: 0.639
user-level: 0.611
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ppc: 0.599
arm: 0.547
PID: 0.527
network: 0.457
boot: 0.453
kernel: 0.449
socket: 0.448
risc-v: 0.444
TCG: 0.412
mistranslation: 0.383
VMM: 0.381
files: 0.343
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i386: 0.248
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KVM: 0.088

regression: 7.0.0 breaks registering process subreaper on Apple silicon
Description of problem:
When running any container on the QEMU virtual guest that is using a utility like `tini` which is trying to register itself as a process subreaper I get an error message like this:

```
[FATAL tini (1)] PR_SET_CHILD_SUBREAPER is unavailable on this platform. Are you using Linux >= 3.4?
```

The issue has been observed by multiple people on Apple silicon Macs, e.g. in these issues:
https://github.com/docker/for-mac/issues/6620#issuecomment-1694380189
https://github.com/GoogleCloudPlatform/spark-on-k8s-operator/issues/1735
Steps to reproduce:
1. Install QEMU 7.0.0+ on an Apple silicon MAC
2. Run a virtual guest
3. Try to register a process subreaper, e.g. like `tini -s` does
Additional information:
the issue was introduced in QEMU 7.0.0 with this commit:
https://gitlab.com/qemu-project/qemu/-/commit/220717a6f46a99031a5b1af964bbf4dec1310440

tini readme talking about process subreaping:
https://github.com/krallin/tini#subreaping