hw/pci-host/remote.c

   1 /*
   2  * Remote PCI host device
   3  *
   4  * Unlike PCI host devices that model physical hardware, the purpose
   5  * of this PCI host is to host multi-process QEMU devices.
   6  *
   7  * Multi-process QEMU extends the PCI host of a QEMU machine into a
   8  * remote process. Any PCI device attached to the remote process is
   9  * visible in the QEMU guest. This allows existing QEMU device models
  10  * to be reused in the remote process.
  11  *
  12  * This PCI host is purely a container for PCI devices. It's fake in the
  13  * sense that the guest never sees this PCI host and has no way of
  14  * accessing it. Its job is just to provide the environment that QEMU
  15  * PCI device models need when running in a remote process.
  16  *
  17  * Copyright © 2018, 2021 Oracle and/or its affiliates.
  18  *
  19  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  20  * See the COPYING file in the top-level directory.
  21  *
  22  */
  23
  24 #include "qemu/osdep.h"
  25
  26 #include "hw/pci/pci.h"
  27 #include "hw/pci/pci_host.h"
  28 #include "hw/pci/pcie_host.h"
  29 #include "hw/qdev-properties.h"
  30 #include "hw/pci-host/remote.h"
  31 #include "exec/memory.h"
  32
  33 static const char *remote_pcihost_root_bus_path(PCIHostState *host_bridge,
  34                                                 PCIBus *rootbus)
  35 {
  36     return "0000:00";
  37 }
  38
  39 static void remote_pcihost_realize(DeviceState *dev, Error **errp)
  40 {
  41     PCIHostState *pci = PCI_HOST_BRIDGE(dev);
  42     RemotePCIHost *s = REMOTE_PCIHOST(dev);
  43
  44     pci->bus = pci_root_bus_new(DEVICE(s), "remote-pci",
  45                                 s->mr_pci_mem, s->mr_sys_io,
  46                                 0, TYPE_PCIE_BUS);
  47 }
  48
  49 static void remote_pcihost_class_init(ObjectClass *klass, void *data)
  50 {
  51     DeviceClass *dc = DEVICE_CLASS(klass);
  52     PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(klass);
  53
  54     hc->root_bus_path = remote_pcihost_root_bus_path;
  55     dc->realize = remote_pcihost_realize;
  56
  57     dc->user_creatable = false;
  58     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
  59     dc->fw_name = "pci";
  60 }
  61
  62 static const TypeInfo remote_pcihost_info = {
  63     .name = TYPE_REMOTE_PCIHOST,
  64     .parent = TYPE_PCIE_HOST_BRIDGE,
  65     .instance_size = sizeof(RemotePCIHost),
  66     .class_init = remote_pcihost_class_init,
  67 };
  68
  69 static void remote_pcihost_register(void)
  70 {
  71     type_register_static(&remote_pcihost_info);
  72 }
  73
  74 type_init(remote_pcihost_register)