Re: [Qemu-devel] [v4][PATCH 4/5] xen:hw:pci-host:piix: create host bridge to passthrough

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Aug 06, 2014 at 05:47:12PM +0800, Chen, Tiejun wrote:
> On 2014/8/6 17:42, Michael S. Tsirkin wrote:
> >On Wed, Aug 06, 2014 at 02:50:34PM +0800, Tiejun Chen wrote:
> >>Implement a pci host bridge specific to passthrough. Actually
> >>this just inherits the standard one.
> >>
> >>This is based on http://patchwork.ozlabs.org/patch/363810/.
> >>
> >>Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
> >>---
> >>  hw/pci-host/piix.c   | 39 +++++++++++++++++++++++++++++++++++++++
> >>  include/hw/i386/pc.h |  2 ++
> >>  2 files changed, 41 insertions(+)
> >>
> >>v4:
> >>
> >>* Rebase
> >>
> >>v3:
> >>
> >>* Rebase
> >>
> >>v2:
> >>
> >>* Just add prefix with XEN_IGD_PASSTHROUGH/xen_igd_passthrough
> >>
> >>diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
> >>index 4330599..5cac398 100644
> >>--- a/hw/pci-host/piix.c
> >>+++ b/hw/pci-host/piix.c
> >>@@ -303,6 +303,17 @@ static int i440fx_initfn(PCIDevice *dev)
> >>      return 0;
> >>  }
> >>
> >>+static int xen_igd_passthrough_i440fx_initfn(PCIDevice *dev)
> >>+{
> >>+    PCII440FXState *d = I440FX_PCI_DEVICE(dev,
> >>+                         TYPE_XEN_IGD_PASSTHROUGH_I440FX_PCI_DEVICE);
> 
> Sorry, I don't understand what you mean.
> 
> i440fx_initfn(PCIDevice *dev) just have one parameter, dev, how to multiplex
> that here?
> 
> Thanks
> Tiejun

You have exactly the same code (except you are doing the cast
differently, but that's just a bug in your code, i440fx_initfn
does it correctly). So nothing to multiplex.

> >>+
> >>+    dev->config[I440FX_SMRAM] = 0x02;
> >>+
> >>+    cpu_smm_register(&i440fx_set_smm, d);
> >>+    return 0;
> >>+}
> >>+
> >>  PCIBus *i440fx_init(const char *host_type, const char *pci_type,
> >>                      PCII440FXState **pi440fx_state,
> >>                      int *piix3_devfn,
> >
> >don't duplicate code.
> >Reuse the function from regular piix.
> 
> 
> 
> >
> >>@@ -703,6 +714,33 @@ static const TypeInfo i440fx_info = {
> >>      .class_init    = i440fx_class_init,
> >>  };
> >>
> >>+static void xen_igd_passthrough_i440fx_class_init(ObjectClass *klass, void *data)
> >>+{
> >>+    DeviceClass *dc = DEVICE_CLASS(klass);
> >>+    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
> >>+
> >>+    k->init = xen_igd_passthrough_i440fx_initfn;
> >>+    k->vendor_id = PCI_VENDOR_ID_INTEL;
> >>+    k->device_id = PCI_DEVICE_ID_INTEL_82441;
> >>+    k->revision = 0x02;
> >>+    k->class_id = PCI_CLASS_BRIDGE_HOST;
> >>+    dc->desc = "IGD PT XEN Host bridge";
> >>+    dc->vmsd = &vmstate_i440fx;
> >>+    /*
> >>+     * PCI-facing part of the host bridge, not usable without the
> >>+     * host-facing part, which can't be device_add'ed, yet.
> >>+     */
> >>+    dc->cannot_instantiate_with_device_add_yet = true;
> >>+    dc->hotpluggable   = false;
> >>+}
> >>+
> >>+static const TypeInfo xen_igd_passthrough_i440fx_info = {
> >>+    .name          = TYPE_XEN_IGD_PASSTHROUGH_I440FX_PCI_DEVICE,
> >>+    .parent        = TYPE_PCI_DEVICE,
> >>+    .instance_size = sizeof(PCII440FXState),
> >>+    .class_init    = xen_igd_passthrough_i440fx_class_init,
> >>+};
> >>+
> >>  static const char *i440fx_pcihost_root_bus_path(PCIHostState *host_bridge,
> >>                                                  PCIBus *rootbus)
> >>  {
> >>@@ -744,6 +782,7 @@ static const TypeInfo i440fx_pcihost_info = {
> >>  static void i440fx_register_types(void)
> >>  {
> >>      type_register_static(&i440fx_info);
> >>+    type_register_static(&xen_igd_passthrough_i440fx_info);
> >>      type_register_static(&piix3_info);
> >>      type_register_static(&piix3_xen_info);
> >>      type_register_static(&i440fx_pcihost_info);
> >>diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> >>index 11fb72f..de34aa6 100644
> >>--- a/include/hw/i386/pc.h
> >>+++ b/include/hw/i386/pc.h
> >>@@ -238,6 +238,8 @@ typedef struct PCII440FXState PCII440FXState;
> >>  #define TYPE_I440FX_PCI_HOST_BRIDGE "i440FX-pcihost"
> >>  #define TYPE_I440FX_PCI_DEVICE "i440FX"
> >>
> >>+#define TYPE_XEN_IGD_PASSTHROUGH_I440FX_PCI_DEVICE "xen-igd-passthrough-i440FX"
> >>+
> >>  PCIBus *i440fx_init(const char *host_type, const char *pci_type,
> >>                      PCII440FXState **pi440fx_state, int *piix_devfn,
> >>                      ISABus **isa_bus, qemu_irq *pic,
> >>--
> >>1.9.1
> >
> >