On 26 March 2013 21:12, Michael S. Tsirkin <m...@redhat.com> wrote: > On Tue, Mar 26, 2013 at 11:17:55AM +0000, Peter Maydell wrote: >> On 26 March 2013 11:08, Arnd Bergmann <a...@arndb.de> wrote: >> > On Tuesday 26 March 2013, Peter Maydell wrote: >> >> On 26 March 2013 10:54, Arnd Bergmann <a...@arndb.de> wrote: >> >> > Yes, very good. We will probably introduce sparse irq support on >> >> > versatile in the near future, and then the value we write into the >> >> > PCI_INTERRUPT_LINE field will become arbitrary from qemu's point >> >> > of view, but I will make sure that we fix the interrupt mapping >> >> > in the kernel at the same time so we always fall into the >> >> > "s->broken_irq_mapping = false;" case. >> >> >> >> Yeah, as long as you avoid the number 27 you're ok :-) >> > >> > Good point. I guess we'll have to keep using a legacy domain for >> > versatile then. >> >> I'm happy to provide some other way for QEMU to detect a >> new working kernel if you want to implement one in the >> kernel, if that's cleaner. > > That's why I suggested writing some number at offset 0x08 > (that's revision ID) in configuration space of device 0 on bus 0. > It's guaranteed harmless on real hardware and QEMU could detect this > write and say "aha new kernel, even though it uses #27".
OK, that makes sense. Would somebody like to provide a kernel patch (preferably against 2.6.35+Arnd's patchset :-)) which just prods that ID space, so I have something to test the QEMU end against? thanks -- PMM
