Q35 - ACPI PCI hot-plug issue with Windows guest

qemu-6.1.0 release

host: Linux x86_64

guest: windows-server-2k22

When using the latest machine type "pc-q35-6.1" Windows Device Manager becomes a little unhappy (displays a yellow exclamation mark) about a new "System Device" with Resource I/O range 0CC4. The Windows error is:

"This device cannot find enough free resources that it can use. (Code 12)"

It appears this device was introduced as part of this patch series:

https://lists.gnu.org/archive/html/qemu-devel/2021-07/msg03306.html

in particular:

#define ACPI_PCIHP_ADDR_ICH9 0x0cc4

The error goes away if using machine type "pc-q35-6.0"

Note: In Windows Device Manager you need to select "Show Hidden Devices" for the yellow exclamation mark to appear. So this is definitely only a minor issue, but possibly untidy nevertheless.

Thanks