1 | /* |
2 | * Virtual Machine Generation ID Device |
3 | * |
4 | * Copyright (C) 2017 Skyport Systems. |
5 | * |
6 | * Author: Ben Warren <ben@skyportsystems.com> |
7 | * |
8 | * This work is licensed under the terms of the GNU GPL, version 2 or later. |
9 | * See the COPYING file in the top-level directory. |
10 | * |
11 | */ |
12 | |
13 | #include "qemu/osdep.h" |
14 | #include "qapi/error.h" |
15 | #include "qapi/qapi-commands-misc.h" |
16 | #include "qemu/module.h" |
17 | #include "hw/acpi/acpi.h" |
18 | #include "hw/acpi/aml-build.h" |
19 | #include "hw/acpi/vmgenid.h" |
20 | #include "hw/nvram/fw_cfg.h" |
21 | #include "hw/qdev-properties.h" |
22 | #include "migration/vmstate.h" |
23 | #include "sysemu/reset.h" |
24 | |
25 | void vmgenid_build_acpi(VmGenIdState *vms, GArray *table_data, GArray *guid, |
26 | BIOSLinker *linker) |
27 | { |
28 | Aml *ssdt, *dev, *scope, *method, *addr, *if_ctx; |
29 | uint32_t vgia_offset; |
30 | QemuUUID guid_le; |
31 | |
32 | /* Fill in the GUID values. These need to be converted to little-endian |
33 | * first, since that's what the guest expects |
34 | */ |
35 | g_array_set_size(guid, VMGENID_FW_CFG_SIZE - ARRAY_SIZE(guid_le.data)); |
36 | guid_le = qemu_uuid_bswap(vms->guid); |
37 | /* The GUID is written at a fixed offset into the fw_cfg file |
38 | * in order to implement the "OVMF SDT Header probe suppressor" |
39 | * see docs/specs/vmgenid.txt for more details |
40 | */ |
41 | g_array_insert_vals(guid, VMGENID_GUID_OFFSET, guid_le.data, |
42 | ARRAY_SIZE(guid_le.data)); |
43 | |
44 | /* Put this in a separate SSDT table */ |
45 | ssdt = init_aml_allocator(); |
46 | |
47 | /* Reserve space for header */ |
48 | acpi_data_push(ssdt->buf, sizeof(AcpiTableHeader)); |
49 | |
50 | /* Storage for the GUID address */ |
51 | vgia_offset = table_data->len + |
52 | build_append_named_dword(ssdt->buf, "VGIA" ); |
53 | scope = aml_scope("\\_SB" ); |
54 | dev = aml_device("VGEN" ); |
55 | aml_append(dev, aml_name_decl("_HID" , aml_string("QEMUVGID" ))); |
56 | aml_append(dev, aml_name_decl("_CID" , aml_string("VM_Gen_Counter" ))); |
57 | aml_append(dev, aml_name_decl("_DDN" , aml_string("VM_Gen_Counter" ))); |
58 | |
59 | /* Simple status method to check that address is linked and non-zero */ |
60 | method = aml_method("_STA" , 0, AML_NOTSERIALIZED); |
61 | addr = aml_local(0); |
62 | aml_append(method, aml_store(aml_int(0xf), addr)); |
63 | if_ctx = aml_if(aml_equal(aml_name("VGIA" ), aml_int(0))); |
64 | aml_append(if_ctx, aml_store(aml_int(0), addr)); |
65 | aml_append(method, if_ctx); |
66 | aml_append(method, aml_return(addr)); |
67 | aml_append(dev, method); |
68 | |
69 | /* the ADDR method returns two 32-bit words representing the lower and |
70 | * upper halves * of the physical address of the fw_cfg blob |
71 | * (holding the GUID) |
72 | */ |
73 | method = aml_method("ADDR" , 0, AML_NOTSERIALIZED); |
74 | |
75 | addr = aml_local(0); |
76 | aml_append(method, aml_store(aml_package(2), addr)); |
77 | |
78 | aml_append(method, aml_store(aml_add(aml_name("VGIA" ), |
79 | aml_int(VMGENID_GUID_OFFSET), NULL), |
80 | aml_index(addr, aml_int(0)))); |
81 | aml_append(method, aml_store(aml_int(0), aml_index(addr, aml_int(1)))); |
82 | aml_append(method, aml_return(addr)); |
83 | |
84 | aml_append(dev, method); |
85 | aml_append(scope, dev); |
86 | aml_append(ssdt, scope); |
87 | |
88 | /* attach an ACPI notify */ |
89 | method = aml_method("\\_GPE._E05" , 0, AML_NOTSERIALIZED); |
90 | aml_append(method, aml_notify(aml_name("\\_SB.VGEN" ), aml_int(0x80))); |
91 | aml_append(ssdt, method); |
92 | |
93 | g_array_append_vals(table_data, ssdt->buf->data, ssdt->buf->len); |
94 | |
95 | /* Allocate guest memory for the Data fw_cfg blob */ |
96 | bios_linker_loader_alloc(linker, VMGENID_GUID_FW_CFG_FILE, guid, 4096, |
97 | false /* page boundary, high memory */); |
98 | |
99 | /* Patch address of GUID fw_cfg blob into the ADDR fw_cfg blob |
100 | * so QEMU can write the GUID there. The address is expected to be |
101 | * < 4GB, but write 64 bits anyway. |
102 | * The address that is patched in is offset in order to implement |
103 | * the "OVMF SDT Header probe suppressor" |
104 | * see docs/specs/vmgenid.txt for more details. |
105 | */ |
106 | bios_linker_loader_write_pointer(linker, |
107 | VMGENID_ADDR_FW_CFG_FILE, 0, sizeof(uint64_t), |
108 | VMGENID_GUID_FW_CFG_FILE, VMGENID_GUID_OFFSET); |
109 | |
110 | /* Patch address of GUID fw_cfg blob into the AML so OSPM can retrieve |
111 | * and read it. Note that while we provide storage for 64 bits, only |
112 | * the least-signficant 32 get patched into AML. |
113 | */ |
114 | bios_linker_loader_add_pointer(linker, |
115 | ACPI_BUILD_TABLE_FILE, vgia_offset, sizeof(uint32_t), |
116 | VMGENID_GUID_FW_CFG_FILE, 0); |
117 | |
118 | build_header(linker, table_data, |
119 | (void *)(table_data->data + table_data->len - ssdt->buf->len), |
120 | "SSDT" , ssdt->buf->len, 1, NULL, "VMGENID" ); |
121 | free_aml_allocator(); |
122 | } |
123 | |
124 | void vmgenid_add_fw_cfg(VmGenIdState *vms, FWCfgState *s, GArray *guid) |
125 | { |
126 | /* Create a read-only fw_cfg file for GUID */ |
127 | fw_cfg_add_file(s, VMGENID_GUID_FW_CFG_FILE, guid->data, |
128 | VMGENID_FW_CFG_SIZE); |
129 | /* Create a read-write fw_cfg file for Address */ |
130 | fw_cfg_add_file_callback(s, VMGENID_ADDR_FW_CFG_FILE, NULL, NULL, NULL, |
131 | vms->vmgenid_addr_le, |
132 | ARRAY_SIZE(vms->vmgenid_addr_le), false); |
133 | } |
134 | |
135 | static void vmgenid_update_guest(VmGenIdState *vms) |
136 | { |
137 | Object *obj = object_resolve_path_type("" , TYPE_ACPI_DEVICE_IF, NULL); |
138 | uint32_t vmgenid_addr; |
139 | QemuUUID guid_le; |
140 | |
141 | if (obj) { |
142 | /* Write the GUID to guest memory */ |
143 | memcpy(&vmgenid_addr, vms->vmgenid_addr_le, sizeof(vmgenid_addr)); |
144 | vmgenid_addr = le32_to_cpu(vmgenid_addr); |
145 | /* A zero value in vmgenid_addr means that BIOS has not yet written |
146 | * the address |
147 | */ |
148 | if (vmgenid_addr) { |
149 | /* QemuUUID has the first three words as big-endian, and expect |
150 | * that any GUIDs passed in will always be BE. The guest, |
151 | * however, will expect the fields to be little-endian. |
152 | * Perform a byte swap immediately before writing. |
153 | */ |
154 | guid_le = qemu_uuid_bswap(vms->guid); |
155 | /* The GUID is written at a fixed offset into the fw_cfg file |
156 | * in order to implement the "OVMF SDT Header probe suppressor" |
157 | * see docs/specs/vmgenid.txt for more details. |
158 | */ |
159 | cpu_physical_memory_write(vmgenid_addr, guid_le.data, |
160 | sizeof(guid_le.data)); |
161 | /* Send _GPE.E05 event */ |
162 | acpi_send_event(DEVICE(obj), ACPI_VMGENID_CHANGE_STATUS); |
163 | } |
164 | } |
165 | } |
166 | |
167 | /* After restoring an image, we need to update the guest memory and notify |
168 | * it of a potential change to VM Generation ID |
169 | */ |
170 | static int vmgenid_post_load(void *opaque, int version_id) |
171 | { |
172 | VmGenIdState *vms = opaque; |
173 | vmgenid_update_guest(vms); |
174 | return 0; |
175 | } |
176 | |
177 | static const VMStateDescription vmstate_vmgenid = { |
178 | .name = "vmgenid" , |
179 | .version_id = 1, |
180 | .minimum_version_id = 1, |
181 | .post_load = vmgenid_post_load, |
182 | .fields = (VMStateField[]) { |
183 | VMSTATE_UINT8_ARRAY(vmgenid_addr_le, VmGenIdState, sizeof(uint64_t)), |
184 | VMSTATE_END_OF_LIST() |
185 | }, |
186 | }; |
187 | |
188 | static void vmgenid_handle_reset(void *opaque) |
189 | { |
190 | VmGenIdState *vms = VMGENID(opaque); |
191 | /* Clear the guest-allocated GUID address when the VM resets */ |
192 | memset(vms->vmgenid_addr_le, 0, ARRAY_SIZE(vms->vmgenid_addr_le)); |
193 | } |
194 | |
195 | static void vmgenid_realize(DeviceState *dev, Error **errp) |
196 | { |
197 | VmGenIdState *vms = VMGENID(dev); |
198 | |
199 | if (!bios_linker_loader_can_write_pointer()) { |
200 | error_setg(errp, "%s requires DMA write support in fw_cfg, " |
201 | "which this machine type does not provide" , VMGENID_DEVICE); |
202 | return; |
203 | } |
204 | |
205 | /* Given that this function is executing, there is at least one VMGENID |
206 | * device. Check if there are several. |
207 | */ |
208 | if (!find_vmgenid_dev()) { |
209 | error_setg(errp, "at most one %s device is permitted" , VMGENID_DEVICE); |
210 | return; |
211 | } |
212 | |
213 | qemu_register_reset(vmgenid_handle_reset, vms); |
214 | |
215 | vmgenid_update_guest(vms); |
216 | } |
217 | |
218 | static Property vmgenid_device_properties[] = { |
219 | DEFINE_PROP_UUID(VMGENID_GUID, VmGenIdState, guid), |
220 | DEFINE_PROP_END_OF_LIST(), |
221 | }; |
222 | |
223 | static void vmgenid_device_class_init(ObjectClass *klass, void *data) |
224 | { |
225 | DeviceClass *dc = DEVICE_CLASS(klass); |
226 | |
227 | dc->vmsd = &vmstate_vmgenid; |
228 | dc->realize = vmgenid_realize; |
229 | dc->props = vmgenid_device_properties; |
230 | dc->hotpluggable = false; |
231 | set_bit(DEVICE_CATEGORY_MISC, dc->categories); |
232 | } |
233 | |
234 | static const TypeInfo vmgenid_device_info = { |
235 | .name = VMGENID_DEVICE, |
236 | .parent = TYPE_DEVICE, |
237 | .instance_size = sizeof(VmGenIdState), |
238 | .class_init = vmgenid_device_class_init, |
239 | }; |
240 | |
241 | static void vmgenid_register_types(void) |
242 | { |
243 | type_register_static(&vmgenid_device_info); |
244 | } |
245 | |
246 | type_init(vmgenid_register_types) |
247 | |
248 | GuidInfo *qmp_query_vm_generation_id(Error **errp) |
249 | { |
250 | GuidInfo *info; |
251 | VmGenIdState *vms; |
252 | Object *obj = find_vmgenid_dev(); |
253 | |
254 | if (!obj) { |
255 | error_setg(errp, "VM Generation ID device not found" ); |
256 | return NULL; |
257 | } |
258 | vms = VMGENID(obj); |
259 | |
260 | info = g_malloc0(sizeof(*info)); |
261 | info->guid = qemu_uuid_unparse_strdup(&vms->guid); |
262 | return info; |
263 | } |
264 | |