Re: [libvirt] [PATCH v6 14/17] [ACKED] qemu: try to put ich9 sound device at 00:1B.0

Real Q35 hardware has an ICH9 chip that includes several integrated devices at particular addresses (see the file docs/q35-chipset.cfg in the qemu source). libvirt already attempts to put the first two sets of ich9 USB2 controllers it finds at 00:1D.* and 00:1A.* to match the real hardware. This patch does the same for the ich9 "HD audio" device. The main inspiration for this patch is that currently the *only* device in a reasonable "workstation" type virtual machine config that requires a legacy PCI slot is the audio device, Without this patch, the standard Q35 machine created by virt-manager will have a dmi-to-pci-bridge and a pci-bridge just for the sound device; with the patch (and if you change the sound device model from the default "ich6" to "ich9"), the machine definition constructed by virt-manager has absolutely no legacy PCI controllers - any legacy PCI devices (e.g. video and sound) are on pcie-root as integrated devices.