xref: /openbmc/qemu/hw/pci-host/remote.c (revision d0bf492f)
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)
75