Re: [Qemu-devel] [PATCH RFC V2 12/17] hw/pci: introduce PCI Expander Bridge (PXB)

[Marcel Apfelbaum <marcel@redhat.com>]

On 02/16/2015 02:58 PM, Alexander Graf wrote:
>
>
> On 16.02.15 10:54, Marcel Apfelbaum wrote:
>> From: Marcel Apfelbaum <marcel.a@redhat.com>
>>
>> PXB is a "light-weight" host bridge whose purpose is to enable
>> the main host bridge to support multiple PCI root buses.
>>
>> As oposed to PCI-2-PCI bridge's secondary bus, PXB's bus
>> is a primary bus and can be associated with a NUMA node
>> (different from the main host bridge) allowing the guest OS
>> to recognize the proximity of a pass-through device to
>> other resources as RAM and CPUs.
>>
>> The PXB is composed from:
>>   - A primary PCI bus (can be associated with a NUMA node)
>>     Acts like a normal pci bus and from the functionality point
>>     of view is an "expansion" of the bus behind the
>>     main host bridge.
>>   - A pci-2-pci bridge behind the primary PCI bus where the actual
>>     devices will be attached.
>>   - A host-bridge PCI device
>>     Situated on the bus behind the main host bridge, allows
>>     the BIOS to configure the bus number and IO/mem resources.
>>     It does not have its own config/data register for configuration
>>     cycles, this being handled by the main host bridge.
>> -  A host-bridge sysbus to comply with QEMU current design.
>>
>> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
>> ---
>>   hw/pci-bridge/Makefile.objs         |   1 +
>>   hw/pci-bridge/pci_expander_bridge.c | 173 ++++++++++++++++++++++++++++++++++++
>>   include/hw/pci/pci.h                |   1 +
>>   3 files changed, 175 insertions(+)
>>   create mode 100644 hw/pci-bridge/pci_expander_bridge.c
>>
>> diff --git a/hw/pci-bridge/Makefile.objs b/hw/pci-bridge/Makefile.objs
>> index 968b369..632e442 100644
>> --- a/hw/pci-bridge/Makefile.objs
>> +++ b/hw/pci-bridge/Makefile.objs
>> @@ -1,4 +1,5 @@
>>   common-obj-y += pci_bridge_dev.o
>> +common-obj-y += pci_expander_bridge.o
>>   common-obj-y += ioh3420.o xio3130_upstream.o xio3130_downstream.o
>>   common-obj-y += i82801b11.o
>>   # NewWorld PowerMac
>> diff --git a/hw/pci-bridge/pci_expander_bridge.c b/hw/pci-bridge/pci_expander_bridge.c
>> new file mode 100644
>> index 0000000..941f3c8
>> --- /dev/null
>> +++ b/hw/pci-bridge/pci_expander_bridge.c
>> @@ -0,0 +1,173 @@
>> +/*
>> + * PCI Expander Bridge Device Emulation
>> + *
>> + * Copyright (C) 2014 Red Hat Inc
>> + *
>> + * Authors:
>> + *   Marcel Apfelbaum <marcel.a@redhat.com>
>> + *
>> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
>> + * See the COPYING file in the top-level directory.
>> + */
>> +
>> +#include "hw/pci/pci.h"
>> +#include "hw/pci/pci_bus.h"
>> +#include "hw/pci/pci_host.h"
>> +#include "hw/pci/pci_bus.h"
>> +#include "qemu/range.h"
>> +#include "qemu/error-report.h"
>> +
>> +#define TYPE_PXB_BUS "pxb-bus"
>> +#define PXB_BUS(obj) OBJECT_CHECK(PXBBus, (obj), TYPE_PXB_BUS)
>> +
>> +typedef struct PXBBus {
>> +    /*< private >*/
>> +    PCIBus parent_obj;
>> +    /*< public >*/
>> +
>> +    char bus_path[8];
>> +} PXBBus;
>> +
>> +#define TYPE_PXB_DEVICE "pxb-device"
>> +#define PXB_DEV(obj) OBJECT_CHECK(PXBDev, (obj), TYPE_PXB_DEVICE)
>> +
>> +typedef struct PXBDev {
>> +    /*< private >*/
>> +    PCIDevice parent_obj;
>> +    /*< public >*/
>> +
>> +    uint8_t bus_nr;
>> +} PXBDev;
>> +
>> +#define TYPE_PXB_HOST "pxb-host"
>> +
>> +static int pxb_bus_num(PCIBus *bus)
>> +{
>> +    PXBDev *pxb = PXB_DEV(bus->parent_dev);
>> +
>> +    return pxb->bus_nr;
>> +}
>> +
>> +static bool pxb_is_root(PCIBus *bus)
>> +{
>> +    return true; /* by definition */
>> +}
>> +
>> +static void pxb_bus_class_init(ObjectClass *class, void *data)
>> +{
>> +    PCIBusClass *pbc = PCI_BUS_CLASS(class);
>> +
>> +    pbc->bus_num = pxb_bus_num;
>> +    pbc->is_root = pxb_is_root;
>> +}
>> +
>> +static const TypeInfo pxb_bus_info = {
>> +    .name          = TYPE_PXB_BUS,
>> +    .parent        = TYPE_PCI_BUS,
>> +    .instance_size = sizeof(PXBBus),
>> +    .class_init    = pxb_bus_class_init,
>> +};
>> +
>> +static const char *pxb_host_root_bus_path(PCIHostState *host_bridge,
>> +                                          PCIBus *rootbus)
>> +{
>> +    PXBBus *bus = PXB_BUS(rootbus);
>> +
>> +    snprintf(bus->bus_path, 8, "0000:%02x", pxb_bus_num(rootbus));
>> +    return bus->bus_path;
>> +}
>> +
>> +static void pxb_host_class_init(ObjectClass *class, void *data)
>> +{
>> +    DeviceClass *dc = DEVICE_CLASS(class);
>> +    PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(class);
>> +
>> +    dc->fw_name = "pci";
>> +    hc->root_bus_path = pxb_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 int pxb_dev_initfn(PCIDevice *dev)
>> +{
>> +    PXBDev *pxb = PXB_DEV(dev);
>> +    DeviceState *ds, *bds;
>> +    PCIHostState *phs;
>> +    PCIBus *bus;
>> +    const char *dev_name = NULL;
>> +
>> +    HOST_BRIDGE_FOREACH(phs) {
>> +        if (pxb->bus_nr == pci_bus_num(phs->bus)) {
>> +            error_report("Bus nr %d is already used by %s.",
>> +                         pxb->bus_nr, phs->bus->qbus.name);
>> +            return -EINVAL;
>> +        }
>> +    }
>> +
>> +    if (dev->qdev.id && *dev->qdev.id) {
>> +        dev_name = dev->qdev.id;
>> +    }
>> +
>> +    ds = qdev_create(NULL, TYPE_PXB_HOST);
>> +    bus = pci_bus_new(ds, "pxb-internal", NULL, NULL, 0, TYPE_PXB_BUS);
>> +
>> +    bus->parent_dev = dev;
>> +    bus->address_space_mem = dev->bus->address_space_mem;
>> +    bus->address_space_io = dev->bus->address_space_io;
>> +    bus->map_irq = pci_swizzle_map_irq_fn;
>> +
>> +    bds = qdev_create(BUS(bus), "pci-bridge");
>> +    bds->id = dev_name;
>> +    qdev_prop_set_uint8(bds, "chassis_nr", pxb->bus_nr);
>> +
>> +    PCI_HOST_BRIDGE(ds)->bus = bus;
>> +
>> +    qdev_init_nofail(ds);
>> +    qdev_init_nofail(bds);
>> +
>> +    pci_word_test_and_set_mask(dev->config + PCI_STATUS,
>> +                               PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
>> +    pci_config_set_class(dev->config, PCI_CLASS_BRIDGE_HOST);
>> +
>> +    return 0;
>> +}
>> +
>> +static Property pxb_dev_properties[] = {
>> +    /* Note: 0 is not a legal a PXB bus number. */
>> +    DEFINE_PROP_UINT8("bus_nr", PXBDev, bus_nr, 0),
>> +    DEFINE_PROP_END_OF_LIST(),
>> +};
>> +
>> +static void pxb_dev_class_init(ObjectClass *klass, void *data)
>> +{
>> +    DeviceClass *dc = DEVICE_CLASS(klass);
>> +    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
>> +
>> +    k->init = pxb_dev_initfn;
>> +    k->vendor_id = PCI_VENDOR_ID_REDHAT;
>> +    k->device_id = PCI_DEVICE_ID_REDHAT_PXB;
>> +    k->class_id = PCI_CLASS_BRIDGE_HOST;
>> +
>> +    dc->desc = "PCI Expander Bridge";
>> +    dc->props = pxb_dev_properties;
>> +}
>> +
>> +static const TypeInfo pxb_dev_info = {
>> +    .name          = TYPE_PXB_DEVICE,
>> +    .parent        = TYPE_PCI_DEVICE,
>> +    .instance_size = sizeof(PXBDev),
>> +    .class_init    = pxb_dev_class_init,
>> +};
>> +
>> +static void pxb_register_types(void)
>> +{
>> +    type_register_static(&pxb_bus_info);
>> +    type_register_static(&pxb_host_info);
>> +    type_register_static(&pxb_dev_info);
>> +}
>> +
>> +type_init(pxb_register_types)
>> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
>> index b7e24d4..e936528 100644
>> --- a/include/hw/pci/pci.h
>> +++ b/include/hw/pci/pci.h
>> @@ -89,6 +89,7 @@
>>   #define PCI_DEVICE_ID_REDHAT_SERIAL4     0x0004
>>   #define PCI_DEVICE_ID_REDHAT_TEST        0x0005
>>   #define PCI_DEVICE_ID_REDHAT_SDHCI       0x0007
>> +#define PCI_DEVICE_ID_REDHAT_PXB         0x0008
>
> This collides with the new PCI root device that should be in the tree by
> now :).
I'll try to keep up! :)
I'll handle it once I rebase.

Thanks,
Marcel

>
>
> Alex
>