xref: /openbmc/qemu/hw/pci-host/remote.c (revision 19f4ed3652e0868dd840d3bfe70cfa2cf41936be)
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  #include "qemu-common.h"
26  
27  #include "hw/pci/pci.h"
28  #include "hw/pci/pci_host.h"
29  #include "hw/pci/pcie_host.h"
30  #include "hw/qdev-properties.h"
31  #include "hw/pci-host/remote.h"
32  #include "exec/memory.h"
33  
34  static const char *remote_pcihost_root_bus_path(PCIHostState *host_bridge,
35                                                  PCIBus *rootbus)
36  {
37      return "0000:00";
38  }
39  
40  static void remote_pcihost_realize(DeviceState *dev, Error **errp)
41  {
42      PCIHostState *pci = PCI_HOST_BRIDGE(dev);
43      RemotePCIHost *s = REMOTE_PCIHOST(dev);
44  
45      pci->bus = pci_root_bus_new(DEVICE(s), "remote-pci",
46                                  s->mr_pci_mem, s->mr_sys_io,
47                                  0, TYPE_PCIE_BUS);
48  }
49  
50  static void remote_pcihost_class_init(ObjectClass *klass, void *data)
51  {
52      DeviceClass *dc = DEVICE_CLASS(klass);
53      PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(klass);
54  
55      hc->root_bus_path = remote_pcihost_root_bus_path;
56      dc->realize = remote_pcihost_realize;
57  
58      dc->user_creatable = false;
59      set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
60      dc->fw_name = "pci";
61  }
62  
63  static const TypeInfo remote_pcihost_info = {
64      .name = TYPE_REMOTE_PCIHOST,
65      .parent = TYPE_PCIE_HOST_BRIDGE,
66      .instance_size = sizeof(RemotePCIHost),
67      .class_init = remote_pcihost_class_init,
68  };
69  
70  static void remote_pcihost_register(void)
71  {
72      type_register_static(&remote_pcihost_info);
73  }
74  
75  type_init(remote_pcihost_register)
76