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_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) 136