On Wed, Nov 05, 2014 at 03:22:59PM +0800, Tiejun Chen wrote: > Currently IGD drivers always need to access PCH by 1f.0, and > PCH vendor/device id is used to identify the card. > > Signed-off-by: Tiejun Chen <tiejun.c...@intel.com> > --- > hw/i386/pc_piix.c | 28 +++++++++++++++++++++++++++- > 1 file changed, 27 insertions(+), 1 deletion(-) > > diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c > index b559181..b19c7a9 100644 > --- a/hw/i386/pc_piix.c > +++ b/hw/i386/pc_piix.c > @@ -50,7 +50,7 @@ > #include "cpu.h" > #include "qemu/error-report.h" > #ifdef CONFIG_XEN > -# include <xen/hvm/hvm_info_table.h> > +#include <xen/hvm/hvm_info_table.h> > #endif > > #define MAX_IDE_BUS 2 > @@ -452,6 +452,31 @@ static void pc_init_isa(MachineState *machine) > } > > #ifdef CONFIG_XEN > +static void xen_igd_passthrough_isa_bridge_create(PCIBus *bus) > +{ > + struct PCIDevice *dev; > + Error *local_err = NULL; > + uint16_t device_id = 0xffff; > + > + /* Currently IGD drivers always need to access PCH by 1f.0. */ > + dev = pci_create_simple(bus, PCI_DEVFN(0x1f, 0), > + "xen-igd-passthrough-isa-bridge"); > + > + /* Identify PCH card with its own real vendor/device ids. > + * Here that vendor id is always PCI_VENDOR_ID_INTEL. > + */ > + if (dev) { > + device_id = object_property_get_int(OBJECT(dev), "device-id", > + &local_err); > + if (!local_err && device_id != 0xffff) { > + pci_config_set_device_id(dev->config, device_id); > + return; > + } > + } > + > + fprintf(stderr, "xen set xen-igd-passthrough-isa-bridge failed\n"); > +} > + > static void pc_xen_hvm_init(MachineState *machine) > { > PCIBus *bus; > @@ -461,6 +486,7 @@ static void pc_xen_hvm_init(MachineState *machine) > bus = pci_find_primary_bus(); > if (bus != NULL) { > pci_create_simple(bus, -1, "xen-platform"); > + xen_igd_passthrough_isa_bridge_create(bus); > } > } > #endif
Can't we defer this step until the GPU is added? This way there won't be need to poke at host device directly, you could get all info from dev->config of the host device. Additionally the correct bridge would be initialized automatically. > -- > 1.9.1