Re: [Qemu-devel] PCI IRQ routing problems

[Fabrice Bellard]

Ed Swierk wrote:
> Linux 2.6.17 running on the latest qemu snapshot is unable to route
> IRQs to more than 4 network interfaces when running without ACPI, and
> is limited to 2 network interfaces with ACPI enabled.
> [...]
> I suspect the problem in the non-ACPI case is caused by a limitation
> in the PCI IRQ routing table in the Bochs BIOS, but I haven't a clue
> how to fix it. Any ideas would be appreciated.

I did not study the issue yet, but I suspect it is a Bochs BIOS issue (I 
remember it declares a limited number of PCI slots for example).

IMHO, all the PCI, MP table and ACPI table init should be moved to the 
Bochs BIOS. I did not do it because it was not strictly necessary to 
have something that works. A simple way to do that is to copy the 
relevant QEMU code in a separate section of the Bochs BIOS and to 
execute it by switching temporarily to 32 bit protected mode in the BIOS 
init code.

Fabrice.