Hi, > > q35 already has a isa bridge @ 1f.0, and it's not a dummy device but > > emulates the ich9 lpc. Just overwriting the identity of that device > > isn't a good idea I think. > > It's not a good idea in practice or in theory? It's exactly what we're > proposing to do for the host bridge.
We don't change the pci ids for the host bridge. It's still a i440fx/q35 host bridge, only the subsystem ID is changed (although I'm sometimes wondering why), and the gfx registers added of course. > Do we know for certain that any of > the emulated ich9 registers do not align with newer chipsets? See drivers/mfd/lpc_ich.c (lpc_chipset_info array). Lots of different versions exist for GPIO wiring. Which probably isn't that much of a problem as I think we don't emulate gpio. For iTCO there are tree different versions too, and we *do* emulate that. > It seems > quite limiting of igd assignment on q35 VMs if we're going to remove > collateral device modification. Should we only claim "legacy" igd > support on 440FX and support only universal passthrough on q35? Thanks, I'll go test this a bit more. Possibly we can drop the whole lpc tweaking. At least when looking at the linux driver code it doesn't seem to be very important. cheers, Gerd
