Re: [Qemu-devel] [PATCH V6 for-2.3 13/26] hw/pci-host: introduce TYPE_PCI_HOST_BRIDGE_SNOOPED interface

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

On Thu, Mar 19, 2015 at 08:52:48PM +0200, Marcel Apfelbaum wrote:
> TYPE_PCI_HOST_BRIDGE_SNOOPED is a special case of host bridge
> whose configuration registers are snooped by other host bridges
> to complete their configuration cycles.
> 
> The interface exposes a list of snooping host bridges that
> shall be used by the hosts implementing this interface
> in order to emulate a snooping mechanism.
> 
> The way that the snooping hosts are registered or how
> the snooping is implemented are out of the interface scope,
> it only provides a way to determine if a host bridge has
> snooping hosts and list them.



> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
> ---
>  hw/pci/pci_host.c         |  8 ++++++++
>  include/hw/pci/pci_host.h | 24 ++++++++++++++++++++++++
>  2 files changed, 32 insertions(+)
> 
> diff --git a/hw/pci/pci_host.c b/hw/pci/pci_host.c
> index 87180c8..288e74c 100644
> --- a/hw/pci/pci_host.c
> +++ b/hw/pci/pci_host.c
> @@ -180,6 +180,12 @@ static const TypeInfo pci_main_host_interface_info = {
>      .parent        = TYPE_INTERFACE,
>  };
>  
> +static const TypeInfo pci_host_bridge_snooped_interface_info = {
> +    .name = TYPE_PCI_HOST_BRIDGE_SNOOPED,
> +    .parent = TYPE_INTERFACE,
> +    .class_size = sizeof(PCIHostBridgeSnoopedClass),
> +};
> +
>  static const TypeInfo pci_host_type_info = {
>      .name = TYPE_PCI_HOST_BRIDGE,
>      .parent = TYPE_SYS_BUS_DEVICE,
> @@ -191,7 +197,9 @@ static const TypeInfo pci_host_type_info = {
>  static void pci_host_register_types(void)
>  {
>      type_register_static(&pci_main_host_interface_info);
> +    type_register_static(&pci_host_bridge_snooped_interface_info);
>      type_register_static(&pci_host_type_info);
> +

extra empty line

>  }
>  
>  type_init(pci_host_register_types)
> diff --git a/include/hw/pci/pci_host.h b/include/hw/pci/pci_host.h
> index 3c72e26..a041919 100644
> --- a/include/hw/pci/pci_host.h
> +++ b/include/hw/pci/pci_host.h
> @@ -63,6 +63,30 @@ typedef struct PCIHostBridgeClass {
>      const char *(*root_bus_path)(PCIHostState *, PCIBus *);
>  } PCIHostBridgeClass;
>  
> +/**
> + * A special case of host bridge whose configuration registers
> + * are snooped by other host bridges to complete their
> + * configuration cycles.
> + */
> +#define TYPE_PCI_HOST_BRIDGE_SNOOPED "pci-host-bridge-snooped"
> +#define TYPE_PCI_HOST_BRIDGE_SNOOPED_CLASS(klass) \
> +     OBJECT_CLASS_CHECK(PCIHostBridgeSnoopedClass, (klass), \
> +                        TYPE_PCI_HOST_BRIDGE_SNOOPED)
> +#define PCI_HOST_BRIDGE_SNOOPED_GET_CLASS(obj) \
> +     OBJECT_GET_CLASS(PCIHostBridgeSnoopedClass, (obj), \
> +                      TYPE_PCI_HOST_BRIDGE_SNOOPED)
> +#define PCI_HOST_BRIDGE_SNOOPED(obj) \
> +     INTERFACE_CHECK(PCIHostState, (obj), \
> +                     TYPE_PCI_HOST_BRIDGE_SNOOPED)
> +
> +typedef struct PCIHostBridgeSnoopedClass {
> +    /* <private> */
> +    InterfaceClass parent_class;
> +
> +    /* <public> */
> +    GPtrArray *(*snooping_hosts)(PCIHostState *);

Why not just add GPtrArray here directly, and add an API to
register/deregister?

> +} PCIHostBridgeSnoopedClass;
> +
>  /* common internal helpers for PCI/PCIe hosts, cut off overflows */
>  void pci_host_config_write_common(PCIDevice *pci_dev, uint32_t addr,
>                                    uint32_t limit, uint32_t val, uint32_t len);
> -- 
> 2.1.0