Re: [Qemu-devel] [RFC v2 1/3] pci_expander_bridge: add type TYPE_PXB_PCIE_HOST

[Marcel Apfelbaum]

On 06/12/2018 12:13 PM, Zihan Yang wrote:
> The inner host bridge created by pxb-pcie is TYPE_PXB_PCI_HOST by default,
> add a new type TYPE_PXB_PCIE_HOST to better utilize the ECAM of PCIe
>
> Signed-off-by: Zihan Yang <address@hidden>
> ---
>   hw/pci-bridge/pci_expander_bridge.c | 118 ++++++++++++++++++++++++++++++++++--
>   1 file changed, 114 insertions(+), 4 deletions(-)
>
> diff --git a/hw/pci-bridge/pci_expander_bridge.c 
> b/hw/pci-bridge/pci_expander_bridge.c
> index e62de42..448b9fb 100644
> --- a/hw/pci-bridge/pci_expander_bridge.c
> +++ b/hw/pci-bridge/pci_expander_bridge.c
> @@ -15,10 +15,12 @@
>   #include "hw/pci/pci.h"
>   #include "hw/pci/pci_bus.h"
>   #include "hw/pci/pci_host.h"
> +#include "hw/pci/pcie_host.h"
>   #include "hw/pci/pci_bridge.h"
>   #include "qemu/range.h"
>   #include "qemu/error-report.h"
>   #include "sysemu/numa.h"
> +#include "qapi/visitor.h"
>   
>   #define TYPE_PXB_BUS "pxb-bus"
>   #define PXB_BUS(obj) OBJECT_CHECK(PXBBus, (obj), TYPE_PXB_BUS)
> @@ -45,7 +47,10 @@ typedef struct PXBDev {
>       PCIDevice parent_obj;
>       /*< public >*/
>   
> -    uint8_t bus_nr;
> +    bool sep_domain;    /* whether it resides in separate PCI segment */
> +    uint32_t domain_nr; /* PCI domain(segment) number, should be 0 if 
> sep_domain is false */
> +    uint8_t max_bus;    /* max number of buses to use */
> +    uint8_t bus_nr;     /* should be 0 when in separate domain */
>       uint16_t numa_node;
>   } PXBDev;
>   
> @@ -58,6 +63,18 @@ static PXBDev *convert_to_pxb(PCIDevice *dev)
>   static GList *pxb_dev_list;
>   
>   #define TYPE_PXB_HOST "pxb-host"
> +#define TYPE_PXB_PCIE_HOST "pxb-pcie-host"
> +#define PXB_PCIE_HOST_DEVICE(obj) \
> +     OBJECT_CHECK(PXBPCIEHost, (obj), TYPE_PXB_PCIE_HOST)
> +
> +typedef struct PXBPCIEHost {
> +    PCIExpressHost parent_obj;
> +
> +    /* should only inherit from PXBDev */
> +    uint32_t domain_nr;
> +    uint8_t bus_nr;
> +    uint8_t max_bus;

I don't think you need the above properties to be part of the
PXBPCIEHost object.

Please see if you can't get a pointer to the PxbDev.
> +} PXBPCIEHost;
>   
>   static int pxb_bus_num(PCIBus *bus)
>   {
> @@ -111,6 +128,31 @@ static const char *pxb_host_root_bus_path(PCIHostState 
> *host_bridge,
>       return bus->bus_path;
>   }
>   
> +/* Use a dedicated function for PCIe since pxb-host does
> + * not have a domain_nr field */
> +static const char *pxb_pcie_host_root_bus_path(PCIHostState *host_bridge,
> +                                          PCIBus *rootbus)
> +{
> +    if (!pci_bus_is_express(rootbus)) {
> +        /* pxb-pcie-host cannot reside on a PCI bus */
> +        return NULL;
> +    }
> +    PXBBus *bus = PXB_PCIE_BUS(rootbus);
> +
> +    snprintf(bus->bus_path, 8, "%04lx:%02x",
> +             object_property_get_uint((Object *)host_bridge, "domain_nr", 
> NULL),
> +             pxb_bus_num(rootbus));
> +    return bus->bus_path;
> +}
> +
> +static void pxb_pcie_host_get_mmcfg_size(Object *obj, Visitor *v, const char 
> *name,
> +                                    void *opaque, Error **errp)
> +{
> +    PCIExpressHost *e = PCIE_HOST_BRIDGE(obj);
> +
> +    visit_type_uint64(v, name, &e->size, errp);
> +}
> +
>   static char *pxb_host_ofw_unit_address(const SysBusDevice *dev)
>   {
>       const PCIHostState *pxb_host;
> @@ -142,6 +184,30 @@ static char *pxb_host_ofw_unit_address(const SysBusDevice 
> *dev)
>       return NULL;
>   }
>   
> +static void pxb_pcie_host_initfn(Object *obj)
> +{
> +    PCIHostState *phb = PCI_HOST_BRIDGE(obj);
> +
> +    memory_region_init_io(&phb->conf_mem, obj, &pci_host_conf_le_ops, phb,
> +                          "pci-conf-idx", 4);
> +    memory_region_init_io(&phb->data_mem, obj, &pci_host_data_le_ops, phb,
> +                          "pci-conf-data", 4);
> +
> +    object_property_add(obj, PCIE_HOST_MCFG_SIZE, "uint64",
> +                         pxb_pcie_host_get_mmcfg_size,
> +                         NULL, NULL, NULL, NULL);
> +
> +}
> +
> +static Property pxb_pcie_host_props[] = {
> +    DEFINE_PROP_UINT64(PCIE_HOST_MCFG_BASE, PXBPCIEHost, parent_obj.base_addr,
> +                        PCIE_BASE_ADDR_UNMAPPED),
> +    DEFINE_PROP_UINT32("domain_nr", PXBPCIEHost, domain_nr, 0),
> +    DEFINE_PROP_UINT8("bus_nr", PXBPCIEHost, bus_nr, 0),
> +    DEFINE_PROP_UINT8("max_bus", PXBPCIEHost, max_bus, 255),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
>   static void pxb_host_class_init(ObjectClass *class, void *data)
>   {
>       DeviceClass *dc = DEVICE_CLASS(class);
> @@ -155,12 +221,34 @@ static void pxb_host_class_init(ObjectClass *class, void 
> *data)
>       hc->root_bus_path = pxb_host_root_bus_path;
>   }
>   
> +static void pxb_pcie_host_class_init(ObjectClass *class, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(class);
> +    SysBusDeviceClass *sbc = SYS_BUS_DEVICE_CLASS(class);
> +    PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(class);
> +
> +    dc->fw_name = "pci";
> +    dc->props = pxb_pcie_host_props;
> +    /* Reason: Internal part of the pxb/pxb-pcie device, not usable by itself 
> */
> +    dc->user_creatable = false;
> +    sbc->explicit_ofw_unit_address = pxb_host_ofw_unit_address;
> +    hc->root_bus_path = pxb_pcie_host_root_bus_path;
> +}
> +
>   static const TypeInfo pxb_host_info = {
>       .name          = TYPE_PXB_HOST,
>       .parent        = TYPE_PCI_HOST_BRIDGE,
>       .class_init    = pxb_host_class_init,
>   };
>   
> +static const TypeInfo pxb_pcie_host_info = {
> +    .name          = TYPE_PXB_PCIE_HOST,
> +    .parent        = TYPE_PCIE_HOST_BRIDGE,
> +    .instance_size = sizeof(PXBPCIEHost),
> +    .instance_init = pxb_pcie_host_initfn,
> +    .class_init    = pxb_pcie_host_class_init,
> +};
> +
>   /*
>    * Registers the PXB bus as a child of pci host root bus.
>    */
> @@ -205,7 +293,10 @@ static gint pxb_compare(gconstpointer a, gconstpointer b)
>   {
>       const PXBDev *pxb_a = a, *pxb_b = b;
>   
> -    return pxb_a->bus_nr < pxb_b->bus_nr ? -1 :
> +    /* check domain_nr, then bus_nr */
> +    return pxb_a->domain_nr < pxb_b->domain_nr ? -1 :
> +           pxb_a->domain_nr > pxb_b->domain_nr ?  1 :
> +           pxb_a->bus_nr < pxb_b->bus_nr ? -1 :
>              pxb_a->bus_nr > pxb_b->bus_nr ?  1 :
>              0;
>   }
> @@ -228,10 +319,17 @@ static void pxb_dev_realize_common(PCIDevice *dev, bool 
> pcie, Error **errp)
>           dev_name = dev->qdev.id;
>       }
>   
> -    ds = qdev_create(NULL, TYPE_PXB_HOST);
>       if (pcie) {
> +        /* either in sep_domain or stay in domain 0 */
> +        g_assert (pxb->sep_domain || pxb->domain_nr == 0);
> +        g_assert (pxb->max_bus >= pxb->bus_nr);
> +        ds = qdev_create(NULL, TYPE_PXB_PCIE_HOST);
> +        qdev_prop_set_uint8(ds, "bus_nr", pxb->bus_nr); //TODO.
> +        qdev_prop_set_uint8(ds, "max_bus", pxb->max_bus);
> +        qdev_prop_set_uint8(ds, "domain_nr", pxb->domain_nr);
>           bus = pci_root_bus_new(ds, dev_name, NULL, NULL, 0, 
> TYPE_PXB_PCIE_BUS);
>       } else {
> +        ds = qdev_create(NULL, TYPE_PXB_HOST);
>           bus = pci_root_bus_new(ds, "pxb-internal", NULL, NULL, 0, 
> TYPE_PXB_BUS);
>           bds = qdev_create(BUS(bus), "pci-bridge");
>           bds->id = dev_name;
> @@ -294,6 +392,17 @@ static Property pxb_dev_properties[] = {
>       DEFINE_PROP_END_OF_LIST(),
>   };
>   
> +static Property pxb_pcie_dev_properties[] = {
> +    /* Note: 0 is not a legal PXB bus number. */
> +    DEFINE_PROP_UINT8("bus_nr", PXBDev, bus_nr, 0),
> +    DEFINE_PROP_UINT16("numa_node", PXBDev, numa_node, NUMA_NODE_UNASSIGNED),
> +    DEFINE_PROP_BOOL("sep_domain", PXBDev, sep_domain, false),
> +    DEFINE_PROP_UINT32("domain_nr", PXBDev, domain_nr, 0),
> +    DEFINE_PROP_UINT8("max_bus", PXBDev, max_bus, 255),
> +

Duplicated properties are not an optimal solution.
I see 2 possible ones:
- Use a macro defining common properties
- Use a base class and put the properties there.

> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
>   static void pxb_dev_class_init(ObjectClass *klass, void *data)
>   {
>       DeviceClass *dc = DEVICE_CLASS(klass);
> @@ -344,7 +453,7 @@ static void pxb_pcie_dev_class_init(ObjectClass *klass, 
> void *data)
>       k->class_id = PCI_CLASS_BRIDGE_HOST;
>   
>       dc->desc = "PCI Express Expander Bridge";
> -    dc->props = pxb_dev_properties;
> +    dc->props = pxb_pcie_dev_properties;
>       dc->hotpluggable = false;
>       set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
>   }
> @@ -365,6 +474,7 @@ static void pxb_register_types(void)
>       type_register_static(&pxb_bus_info);
>       type_register_static(&pxb_pcie_bus_info);
>       type_register_static(&pxb_host_info);
> +    type_register_static(&pxb_pcie_host_info);
>       type_register_static(&pxb_dev_info);
>       type_register_static(&pxb_pcie_dev_info);
>   }

Looking good!

Thanks,
Marcel