Re: [PATCH] Make virtio devices multi-function

Marcelo Tosatti
2008-04-23T20:57:50Z

> > It sounds reasonable to expect so. ACPI has objects for devices, not
> > functions (IIRC).
>
> So what I dislike about multifunction devices is the fact that a single
> slot shares an IRQ, and that special code is required in the QEMU
> drivers (virtio guest capability might not always be present).

Actually this is not true. It is possible to have separate IRQ's for
different devices residing in the same slot, changes are required to the
ACPI tables though.

> I don't see any need for using them if we can extend PCI slots...
>
> > Maybe require explicit device/function assignment on the command line?
> > It will be managed anyway.
>
> ACPI does support hotplugging of individual functions inside slots,
> not sure how well does Linux (and other OSes) support that.. should be
> transparent though.