| 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 "system/memory.h" |
| 17 | #include "system/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_new0(RemoteIommuElem, 1); |
| 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 | static const PCIIOMMUOps remote_iommu_ops = { |
| 104 | .get_address_space = remote_iommu_find_add_as, |
| 105 | }; |
| 106 | |
| 107 | void remote_iommu_setup(PCIBus *pci_bus) |
| 108 | { |
| 109 | RemoteIommu *iommu = NULL; |
| 110 | |
| 111 | g_assert(pci_bus); |
| 112 | |
| 113 | iommu = REMOTE_IOMMU(object_new(TYPE_REMOTE_IOMMU)); |
| 114 | |
| 115 | pci_setup_iommu(pci_bus, &remote_iommu_ops, iommu); |
| 116 | |
| 117 | object_property_add_child(OBJECT(pci_bus), "remote-iommu", OBJECT(iommu)); |
| 118 | |
| 119 | object_unref(OBJECT(iommu)); |
| 120 | } |
| 121 | |
| 122 | static const TypeInfo remote_iommu_info = { |
| 123 | .name = TYPE_REMOTE_IOMMU, |
| 124 | .parent = TYPE_OBJECT, |
| 125 | .instance_size = sizeof(RemoteIommu), |
| 126 | .instance_init = remote_iommu_init, |
| 127 | .instance_finalize = remote_iommu_finalize, |
| 128 | }; |
| 129 | |
| 130 | static void remote_iommu_register_types(void) |
| 131 | { |
| 132 | type_register_static(&remote_iommu_info); |
| 133 | } |
| 134 | |
| 135 | type_init(remote_iommu_register_types) |