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."
[+cc Robert]
On Mon, Feb 15, 2021 at 05:53:51PM +0100, Paul Menzel wrote:
> 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."
Do you know whether qemu implements extended config space? Extended
config space is offsets 0x100-0xfff. I think Linux only supports
extended capabilities in that area (AER, VC, ACS, SR-IOV, etc). Most
of these are probably not of interest in a virtualized environment, so
I wouldn't be surprised if qemu doesn't support them.
Bjorn