id = 2874
title = "AMD Ryzen 9950x with -smp option yields \"warning: This family of AMD CPU doesn't support hyperthreading\""
state = "opened"
created_at = "2025-03-19T16:29:51.347Z"
closed_at = "n/a"
labels = ["target: i386"]
url = "https://gitlab.com/qemu-project/qemu/-/issues/2874"
host-os = "Guix System"
host-arch = "x86_64"
qemu-version = "9.1.3"
guest-os = "n/a"
guest-arch = "n/a"
description = """When using the above -smp option (`-smp 32,sockets=1,dies=1,clusters=1,cores=16,threads=2`), which should be valid for the Ryzen 9950X 16 cores / 32 threads CPU, QEMU prints:
```
qemu-system-x86_64: warning: This family of AMD CPU doesn't support hyperthreading(2). Please configure -smp options properly or try enabling topoext feature.
```
This is unexpected.  This CPU should support hyperthreading out of the box, it seems."""
reproduce = """1. Run command above on Ryzen 9950X or similar CPU."""
additional = "n/a"