Re: [Qemu-devel] [PATCH 2/4] pci: Add generic PCIe host bridge

[Claudio Fontana <claudio.fontana@huawei.com>]

On 06.01.2015 17:03, Alexander Graf wrote:
> With simple exposure of MMFG, ioport window, mmio window and an IRQ line we
> can successfully create a workable PCIe host bridge that can be mapped anywhere
> and only needs to get described to the OS using whatever means it likes.
> 
> This patch implements such a "generic" host bridge. It only supports a single
> legacy IRQ line so far. MSIs need to be handled external to the host bridge.
> 
> This device is particularly useful for the "pci-host-ecam-generic" driver in
> Linux.
> 
> Signed-off-by: Alexander Graf <agraf@suse.de>
> ---
>  hw/pci-host/Makefile.objs  |   1 +
>  hw/pci-host/gpex.c         | 156 +++++++++++++++++++++++++++++++++++++++++++++
>  include/hw/pci-host/gpex.h |  56 ++++++++++++++++
>  3 files changed, 213 insertions(+)
>  create mode 100644 hw/pci-host/gpex.c
>  create mode 100644 include/hw/pci-host/gpex.h
> 
> diff --git a/hw/pci-host/Makefile.objs b/hw/pci-host/Makefile.objs
> index bb65f9c..45f1f0e 100644
> --- a/hw/pci-host/Makefile.objs
> +++ b/hw/pci-host/Makefile.objs
> @@ -15,3 +15,4 @@ common-obj-$(CONFIG_PCI_APB) += apb.o
>  common-obj-$(CONFIG_FULONG) += bonito.o
>  common-obj-$(CONFIG_PCI_PIIX) += piix.o
>  common-obj-$(CONFIG_PCI_Q35) += q35.o
> +common-obj-$(CONFIG_PCI_GENERIC) += gpex.o
> diff --git a/hw/pci-host/gpex.c b/hw/pci-host/gpex.c
> new file mode 100644
> index 0000000..bd62a3c
> --- /dev/null
> +++ b/hw/pci-host/gpex.c
> @@ -0,0 +1,156 @@
> +/*
> + * QEMU Generic PCI Express Bridge Emulation
> + *
> + * Copyright (C) 2015 Alexander Graf <agraf@suse.de>
> + *
> + * Code loosely based on q35.c.
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to deal
> + * in the Software without restriction, including without limitation the rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +#include "hw/hw.h"
> +#include "hw/pci-host/gpex.h"
> +
> +/****************************************************************************
> + * GPEX host
> + */
> +
> +static void gpex_set_irq(void *opaque, int irq_num, int level)
> +{
> +    GPEXHost *s = opaque;
> +
> +    qemu_set_irq(s->irq, level);
> +}
> +
> +static int gpex_map_irq(PCIDevice *pci_dev, int irq_num)
> +{
> +    /* We only support one IRQ line so far */
> +    return 0;
> +}
> +
> +static void gpex_host_realize(DeviceState *dev, Error **errp)
> +{
> +    PCIHostState *pci = PCI_HOST_BRIDGE(dev);
> +    GPEXHost *s = GPEX_HOST(dev);
> +    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
> +    PCIExpressHost *pex = PCIE_HOST_BRIDGE(dev);
> +
> +    pcie_host_mmcfg_init(pex, PCIE_MMCFG_SIZE_MIN);
> +    memory_region_init(&s->io_mmio, OBJECT(s), "gpex_mmio", s->mmio_window_size);
> +    memory_region_init(&s->io_ioport, OBJECT(s), "gpex_ioport", 64 * 1024);
> +
> +    sysbus_init_mmio(sbd, &pex->mmio);
> +    sysbus_init_mmio(sbd, &s->io_mmio);
> +    sysbus_init_mmio(sbd, &s->io_ioport);
> +    sysbus_init_irq(sbd, &s->irq);
> +
> +    pci->bus = pci_register_bus(dev, "pcie.0", gpex_set_irq, gpex_map_irq, s,
> +                              &s->io_mmio, &s->io_ioport, 0, 1, TYPE_PCIE_BUS);
> +
> +    qdev_set_parent_bus(DEVICE(&s->gpex_root), BUS(pci->bus));
> +    qdev_init_nofail(DEVICE(&s->gpex_root));
> +}
> +
> +static const char *gpex_host_root_bus_path(PCIHostState *host_bridge,
> +                                          PCIBus *rootbus)
> +{
> +    return "0000:00";
> +}
> +
> +static Property gpex_root_props[] = {
> +    DEFINE_PROP_UINT64("mmio_window_size", GPEXHost, mmio_window_size, 1ULL << 32),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void gpex_host_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(klass);
> +
> +    hc->root_bus_path = gpex_host_root_bus_path;
> +    dc->realize = gpex_host_realize;
> +    dc->props = gpex_root_props;
> +    set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
> +    dc->fw_name = "pci";
> +}
> +
> +static void gpex_host_initfn(Object *obj)
> +{
> +    GPEXHost *s = GPEX_HOST(obj);
> +
> +    object_initialize(&s->gpex_root, sizeof(s->gpex_root), TYPE_GPEX_ROOT_DEVICE);
> +    object_property_add_child(OBJECT(s), "gpex_root", OBJECT(&s->gpex_root), NULL);
> +    qdev_prop_set_uint32(DEVICE(&s->gpex_root), "addr", PCI_DEVFN(0, 0));
> +    qdev_prop_set_bit(DEVICE(&s->gpex_root), "multifunction", false);
> +}
> +
> +static const TypeInfo gpex_host_info = {
> +    .name       = TYPE_GPEX_HOST,
> +    .parent     = TYPE_PCIE_HOST_BRIDGE,
> +    .instance_size = sizeof(GPEXHost),
> +    .instance_init = gpex_host_initfn,
> +    .class_init = gpex_host_class_init,
> +};
> +
> +/****************************************************************************
> + * GPEX Root D0:F0
> + */
> +
> +static const VMStateDescription vmstate_gpex_root = {
> +    .name = "gpex_root",
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_PCI_DEVICE(parent_obj, GPEXRootState),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
> +static void gpex_root_class_init(ObjectClass *klass, void *data)
> +{
> +    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +
> +    set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
> +    dc->desc = "Host bridge";
> +    dc->vmsd = &vmstate_gpex_root;
> +    k->vendor_id = PCI_VENDOR_ID_REDHAT;
> +    k->device_id = PCI_DEVICE_ID_REDHAT_BRIDGE;
> +    k->revision = 0;
> +    k->class_id = PCI_CLASS_BRIDGE_HOST;
> +    /*
> +     * 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;
> +}
> +
> +static const TypeInfo gpex_root_info = {
> +    .name = TYPE_GPEX_ROOT_DEVICE,
> +    .parent = TYPE_PCI_DEVICE,
> +    .instance_size = sizeof(GPEXRootState),
> +    .class_init = gpex_root_class_init,
> +};
> +
> +static void gpex_register(void)
> +{
> +    type_register_static(&gpex_root_info);
> +    type_register_static(&gpex_host_info);
> +}
> +
> +type_init(gpex_register);
> diff --git a/include/hw/pci-host/gpex.h b/include/hw/pci-host/gpex.h
> new file mode 100644
> index 0000000..5cf2073
> --- /dev/null
> +++ b/include/hw/pci-host/gpex.h
> @@ -0,0 +1,56 @@
> +/*
> + * gpex.h
> + *
> + * Copyright (C) 2015 Alexander Graf <agraf@suse.de>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; if not, see <http://www.gnu.org/licenses/>
> + */
> +
> +#ifndef HW_GPEX_H
> +#define HW_GPEX_H
> +
> +#include "hw/hw.h"
> +#include "hw/sysbus.h"
> +#include "hw/pci/pci.h"
> +#include "hw/pci/pcie_host.h"
> +
> +#define TYPE_GPEX_HOST "gpex-pcihost"
> +#define GPEX_HOST(obj) \
> +     OBJECT_CHECK(GPEXHost, (obj), TYPE_GPEX_HOST)
> +
> +#define TYPE_GPEX_ROOT_DEVICE "gpex-root"
> +#define MCH_PCI_DEVICE(obj) \
> +     OBJECT_CHECK(GPEXRootState, (obj), TYPE_GPEX_ROOT_DEVICE)
> +
> +typedef struct GPEXRootState {
> +    /*< private >*/
> +    PCIDevice parent_obj;
> +    /*< public >*/
> +} GPEXRootState;
> +
> +typedef struct GPEXHost {
> +    /*< private >*/
> +    PCIExpressHost parent_obj;
> +    /*< public >*/
> +
> +    GPEXRootState gpex_root;
> +
> +    MemoryRegion io_ioport;
> +    MemoryRegion io_mmio;
> +    qemu_irq irq;
> +
> +    uint64_t mmio_window_size;
> +} GPEXHost;
> +
> +#endif /* HW_GPEX_H */
> 

Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>


-- 
Claudio Fontana
Server Virtualization Architect
Huawei Technologies Duesseldorf GmbH
Riesstraße 25 - 80992 München

office: +49 89 158834 4135
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