Merge tag 'for-upstream' of git://repo.or.cz/qemu/kevin into staging
[qemu.git] / hw / remote / iommu.c
1 /**
2 * IOMMU for remote device
3 *
4 * Copyright © 2022 Oracle and/or its affiliates.
5 *
6 * This work is licensed under the terms of the GNU GPL, version 2 or later.
7 * See the COPYING file in the top-level directory.
8 *
9 */
10
11 #include "qemu/osdep.h"
12
13 #include "hw/remote/iommu.h"
14 #include "hw/pci/pci_bus.h"
15 #include "hw/pci/pci.h"
16 #include "exec/memory.h"
17 #include "exec/address-spaces.h"
18 #include "trace.h"
19
20 /**
21 * IOMMU for TYPE_REMOTE_MACHINE - manages DMA address space isolation
22 * for remote machine. It is used by TYPE_VFIO_USER_SERVER.
23 *
24 * - Each TYPE_VFIO_USER_SERVER instance handles one PCIDevice on a PCIBus.
25 * There is one RemoteIommu per PCIBus, so the RemoteIommu tracks multiple
26 * PCIDevices by maintaining a ->elem_by_devfn mapping.
27 *
28 * - memory_region_init_iommu() is not used because vfio-user MemoryRegions
29 * will be added to the elem->mr container instead. This is more natural
30 * than implementing the IOMMUMemoryRegionClass APIs since vfio-user
31 * provides something that is close to a full-fledged MemoryRegion and
32 * not like an IOMMU mapping.
33 *
34 * - When a device is hot unplugged, the elem->mr reference is dropped so
35 * all vfio-user MemoryRegions associated with this vfio-user server are
36 * destroyed.
37 */
38
39 static AddressSpace *remote_iommu_find_add_as(PCIBus *pci_bus,
40 void *opaque, int devfn)
41 {
42 RemoteIommu *iommu = opaque;
43 RemoteIommuElem *elem = NULL;
44
45 qemu_mutex_lock(&iommu->lock);
46
47 elem = g_hash_table_lookup(iommu->elem_by_devfn, INT2VOIDP(devfn));
48
49 if (!elem) {
50 elem = g_malloc0(sizeof(RemoteIommuElem));
51 g_hash_table_insert(iommu->elem_by_devfn, INT2VOIDP(devfn), elem);
52 }
53
54 if (!elem->mr) {
55 elem->mr = MEMORY_REGION(object_new(TYPE_MEMORY_REGION));
56 memory_region_set_size(elem->mr, UINT64_MAX);
57 address_space_init(&elem->as, elem->mr, NULL);
58 }
59
60 qemu_mutex_unlock(&iommu->lock);
61
62 return &elem->as;
63 }
64
65 void remote_iommu_unplug_dev(PCIDevice *pci_dev)
66 {
67 AddressSpace *as = pci_device_iommu_address_space(pci_dev);
68 RemoteIommuElem *elem = NULL;
69
70 if (as == &address_space_memory) {
71 return;
72 }
73
74 elem = container_of(as, RemoteIommuElem, as);
75
76 address_space_destroy(&elem->as);
77
78 object_unref(elem->mr);
79
80 elem->mr = NULL;
81 }
82
83 static void remote_iommu_init(Object *obj)
84 {
85 RemoteIommu *iommu = REMOTE_IOMMU(obj);
86
87 iommu->elem_by_devfn = g_hash_table_new_full(NULL, NULL, NULL, g_free);
88
89 qemu_mutex_init(&iommu->lock);
90 }
91
92 static void remote_iommu_finalize(Object *obj)
93 {
94 RemoteIommu *iommu = REMOTE_IOMMU(obj);
95
96 qemu_mutex_destroy(&iommu->lock);
97
98 g_hash_table_destroy(iommu->elem_by_devfn);
99
100 iommu->elem_by_devfn = NULL;
101 }
102
103 void remote_iommu_setup(PCIBus *pci_bus)
104 {
105 RemoteIommu *iommu = NULL;
106
107 g_assert(pci_bus);
108
109 iommu = REMOTE_IOMMU(object_new(TYPE_REMOTE_IOMMU));
110
111 pci_setup_iommu(pci_bus, remote_iommu_find_add_as, iommu);
112
113 object_property_add_child(OBJECT(pci_bus), "remote-iommu", OBJECT(iommu));
114
115 object_unref(OBJECT(iommu));
116 }
117
118 static const TypeInfo remote_iommu_info = {
119 .name = TYPE_REMOTE_IOMMU,
120 .parent = TYPE_OBJECT,
121 .instance_size = sizeof(RemoteIommu),
122 .instance_init = remote_iommu_init,
123 .instance_finalize = remote_iommu_finalize,
124 };
125
126 static void remote_iommu_register_types(void)
127 {
128 type_register_static(&remote_iommu_info);
129 }
130
131 type_init(remote_iommu_register_types)