acpi PNP0A03:00: fail to add MMCONFIG information, can't access extended PCI configuration space under this bridge.

[Paul Menzel]

Dear Linux folks,


All the way up to QEMU emulator version 5.2.0 (Debian 1:5.2+dfsg-5) and 
Linux 5.10.13, Linux logs the warning below:

    acpi PNP0A03:00: fail to add MMCONFIG information, can't access 
extended PCI configuration space under this bridge.

One way to reproduce it:

    qemu-system-x86_64 -enable-kvm -m 2G -hda /dev/shm/debian.img 
-kernel /boot/vmlinuz-5.10.0-3-amd64 -initrd 
/boot/initrd.img-5.10.0-3-amd64 -append root="/dev/sda1 
console=ttyS0,115200" -serial stdio

Please find more details and the full log in the Bugzilla issue #211765 [1].


Kind regards,

Paul


[1]: https://bugzilla.kernel.org/show_bug.cgi?id=211765
     "[Bug 211765] acpi PNP0A03:00: fail to add MMCONFIG information, 
can't access extended PCI configuration space under this bridge."