Commit 40d14bef authored by Marcel Apfelbaum's avatar Marcel Apfelbaum Committed by Michael S. Tsirkin
Browse files

hw/pci: introduce PCI Expander Bridge (PXB) 



PXB is a "light-weight" host bridge whose purpose is to enable
the main host bridge to support multiple PCI root buses
for pc machines.

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: default avatarMarcel Apfelbaum <marcel@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Acked-by: default avatarLaszlo Ersek <lersek@redhat.com>
parent cb2ed8b3

hw/pci-bridge/Makefile.objs

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Original line number Diff line number Diff line 
common-obj-y += pci_bridge_dev.o

common-obj-y += pci_expander_bridge.o

common-obj-$(CONFIG_XIO3130) += xio3130_upstream.o xio3130_downstream.o

common-obj-$(CONFIG_IOH3420) += ioh3420.o

common-obj-$(CONFIG_I82801B11) += i82801b11.o

hw/pci-bridge/pci_expander_bridge.c

0 → 100644
+196 −0
Original line number Diff line number Diff line 
/*

 * PCI Expander Bridge Device Emulation

 *

 * Copyright (C) 2015 Red Hat Inc

 *

 * Authors:

 *   Marcel Apfelbaum <marcel@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 "hw/i386/pc.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"

#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,

};



/*

 * Registers the PXB bus as a child of the i440fx root bus.

 *

 * Returns 0 on successs, -1 if i440fx host was not

 * found or the bus number is already in use.

 */

static int pxb_register_bus(PCIDevice *dev, PCIBus *pxb_bus)

{

    PCIBus *bus = dev->bus;

    int pxb_bus_num = pci_bus_num(pxb_bus);



    if (bus->parent_dev) {

        error_report("PXB devices can be attached only to root bus.");

        return -1;

    }



    QLIST_FOREACH(bus, &bus->child, sibling) {

        if (pci_bus_num(bus) == pxb_bus_num) {

            error_report("Bus %d is already in use.", pxb_bus_num);

            return -1;

        }

    }

    QLIST_INSERT_HEAD(&dev->bus->child, pxb_bus, sibling);



    return 0;

}



static int pxb_dev_initfn(PCIDevice *dev)

{

    PXBDev *pxb = PXB_DEV(dev);

    DeviceState *ds, *bds;

    PCIBus *bus;

    const char *dev_name = NULL;



    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;



    if (pxb_register_bus(dev, bus)) {

        return -EINVAL;

    }



    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)

include/hw/pci/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -91,6 +91,7 @@ 
#define PCI_DEVICE_ID_REDHAT_ROCKER      0x0006

#define PCI_DEVICE_ID_REDHAT_SDHCI       0x0007

#define PCI_DEVICE_ID_REDHAT_PCIE_HOST   0x0008

#define PCI_DEVICE_ID_REDHAT_PXB         0x0009

#define PCI_DEVICE_ID_REDHAT_QXL         0x0100



#define FMT_PCIBUS                      PRIx64