On 24 March 2013 19:17, Michael S. Tsirkin <m...@redhat.com> wrote: > On Sun, Mar 24, 2013 at 04:58:37PM +0100, Aurelien Jarno wrote: >> On Sun, Mar 24, 2013 at 11:32:30AM +0000, Peter Maydell wrote: >> > I've provided a property for enabling the old broken IRQ mapping; >> > this can be enabled with the command line option: >> > -global versatile_pci.broken-irq-mapping=1 >> > >> > (If anybody wants to suggest a better way of handling this please do.) >> >> Do you have a pointer to the corresponding kernel patch? Is it possible >> to get the kernel to detect if it should use the correct or the broken >> IRQ mapping? > > Alternatively, or additionally, how about detecting the correct or > the incorrect kernel and updating the mapping? > For example, maybe we could do this using the > IRQ value written into the device pci config register?
Yeah, ideally being able to detect the buggy kernel would be good; I can't see anything at the controller level that would do though, and I don't really know enough about PCI to know about generic PCI stuff that would work. (Why would the OS need to tell the device anything about its IRQ if it's hardwired?) > If we can't find anything, maybe add our own register > so the same qemu config can support old and new kernels? Then the new kernel wouldn't work on real hardware... -- PMM
