id = 2530
title = "Duplicate ACPI _SUN"
state = "opened"
created_at = "2024-08-22T17:49:34.327Z"
closed_at = "n/a"
labels = ["ACPI", "device: PCI", "target: i386"]
url = "https://gitlab.com/qemu-project/qemu/-/issues/2530"
host-os = "Fedora 40"
host-arch = "x86"
qemu-version = "qemu-8.2.2-1.fc40"
guest-os = "Centos 9 stream (any recent Linux should do)"
guest-arch = "x86"
description = """ACPI _SUN is `the slot-unique ID number for a slot`, but qemu uses `PCI_SLOT()` which is definitely not unique
https://gitlab.com/qemu-project/qemu/-/blob/407f9a4b121eb65166375c410e14d7b704bc1106/hw/i386/acpi-build.c#L524"""
reproduce = """1. Create a linux VM with 2 virtio NICs
2. Look at the ACPI _SUN of the virtio-pci devices (firmware_node/sun)

Both virtio-pci devices have _SUN == 0
```
#"""
additional = """In systemd we recently introduced code to use firmware_node/sun information for NIC naming
https://github.com/systemd/systemd/commit/0a4ecc54cb9f2d3418b970c51bfadb69c34ae9eb

but having duplicate _SUN is of course problematic
https://github.com/systemd/systemd/issues/34082"""