xref: /openbmc/qemu/hw/i386/pc_sysfw.c (revision 6f03770d)
1 /*
2  * QEMU PC System Firmware
3  *
4  * Copyright (c) 2003-2004 Fabrice Bellard
5  * Copyright (c) 2011-2012 Intel Corporation
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a copy
8  * of this software and associated documentation files (the "Software"), to deal
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23  * THE SOFTWARE.
24  */
25 
26 #include "qemu/osdep.h"
27 #include "qemu-common.h"
28 #include "qapi/error.h"
29 #include "sysemu/block-backend.h"
30 #include "qemu/error-report.h"
31 #include "qemu/option.h"
32 #include "qemu/units.h"
33 #include "hw/sysbus.h"
34 #include "hw/i386/x86.h"
35 #include "hw/i386/pc.h"
36 #include "hw/loader.h"
37 #include "hw/qdev-properties.h"
38 #include "sysemu/sysemu.h"
39 #include "hw/block/flash.h"
40 #include "sysemu/kvm.h"
41 #include "sysemu/sev.h"
42 
43 #define FLASH_SECTOR_SIZE 4096
44 
45 static void pc_isa_bios_init(MemoryRegion *rom_memory,
46                              MemoryRegion *flash_mem,
47                              int ram_size)
48 {
49     int isa_bios_size;
50     MemoryRegion *isa_bios;
51     uint64_t flash_size;
52     void *flash_ptr, *isa_bios_ptr;
53 
54     flash_size = memory_region_size(flash_mem);
55 
56     /* map the last 128KB of the BIOS in ISA space */
57     isa_bios_size = MIN(flash_size, 128 * KiB);
58     isa_bios = g_malloc(sizeof(*isa_bios));
59     memory_region_init_ram(isa_bios, NULL, "isa-bios", isa_bios_size,
60                            &error_fatal);
61     memory_region_add_subregion_overlap(rom_memory,
62                                         0x100000 - isa_bios_size,
63                                         isa_bios,
64                                         1);
65 
66     /* copy ISA rom image from top of flash memory */
67     flash_ptr = memory_region_get_ram_ptr(flash_mem);
68     isa_bios_ptr = memory_region_get_ram_ptr(isa_bios);
69     memcpy(isa_bios_ptr,
70            ((uint8_t*)flash_ptr) + (flash_size - isa_bios_size),
71            isa_bios_size);
72 
73     memory_region_set_readonly(isa_bios, true);
74 }
75 
76 static PFlashCFI01 *pc_pflash_create(PCMachineState *pcms,
77                                      const char *name,
78                                      const char *alias_prop_name)
79 {
80     DeviceState *dev = qdev_new(TYPE_PFLASH_CFI01);
81 
82     qdev_prop_set_uint64(dev, "sector-length", FLASH_SECTOR_SIZE);
83     qdev_prop_set_uint8(dev, "width", 1);
84     qdev_prop_set_string(dev, "name", name);
85     object_property_add_child(OBJECT(pcms), name, OBJECT(dev));
86     object_property_add_alias(OBJECT(pcms), alias_prop_name,
87                               OBJECT(dev), "drive");
88     /*
89      * The returned reference is tied to the child property and
90      * will be removed with object_unparent.
91      */
92     object_unref(OBJECT(dev));
93     return PFLASH_CFI01(dev);
94 }
95 
96 void pc_system_flash_create(PCMachineState *pcms)
97 {
98     PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
99 
100     if (pcmc->pci_enabled) {
101         pcms->flash[0] = pc_pflash_create(pcms, "system.flash0",
102                                           "pflash0");
103         pcms->flash[1] = pc_pflash_create(pcms, "system.flash1",
104                                           "pflash1");
105     }
106 }
107 
108 void pc_system_flash_cleanup_unused(PCMachineState *pcms)
109 {
110     char *prop_name;
111     int i;
112     Object *dev_obj;
113 
114     assert(PC_MACHINE_GET_CLASS(pcms)->pci_enabled);
115 
116     for (i = 0; i < ARRAY_SIZE(pcms->flash); i++) {
117         dev_obj = OBJECT(pcms->flash[i]);
118         if (!object_property_get_bool(dev_obj, "realized", &error_abort)) {
119             prop_name = g_strdup_printf("pflash%d", i);
120             object_property_del(OBJECT(pcms), prop_name);
121             g_free(prop_name);
122             object_unparent(dev_obj);
123             pcms->flash[i] = NULL;
124         }
125     }
126 }
127 
128 #define OVMF_TABLE_FOOTER_GUID "96b582de-1fb2-45f7-baea-a366c55a082d"
129 
130 static uint8_t *ovmf_table;
131 static int ovmf_table_len;
132 
133 static void pc_system_parse_ovmf_flash(uint8_t *flash_ptr, size_t flash_size)
134 {
135     uint8_t *ptr;
136     QemuUUID guid;
137     int tot_len;
138 
139     /* should only be called once */
140     if (ovmf_table) {
141         return;
142     }
143 
144     if (flash_size < TARGET_PAGE_SIZE) {
145         return;
146     }
147 
148     /*
149      * if this is OVMF there will be a table footer
150      * guid 48 bytes before the end of the flash file.  If it's
151      * not found, silently abort the flash parsing.
152      */
153     qemu_uuid_parse(OVMF_TABLE_FOOTER_GUID, &guid);
154     guid = qemu_uuid_bswap(guid); /* guids are LE */
155     ptr = flash_ptr + flash_size - 48;
156     if (!qemu_uuid_is_equal((QemuUUID *)ptr, &guid)) {
157         return;
158     }
159 
160     /* if found, just before is two byte table length */
161     ptr -= sizeof(uint16_t);
162     tot_len = le16_to_cpu(*(uint16_t *)ptr) - sizeof(guid) - sizeof(uint16_t);
163 
164     if (tot_len <= 0) {
165         return;
166     }
167 
168     ovmf_table = g_malloc(tot_len);
169     ovmf_table_len = tot_len;
170 
171     /*
172      * ptr is the foot of the table, so copy it all to the newly
173      * allocated ovmf_table and then set the ovmf_table pointer
174      * to the table foot
175      */
176     memcpy(ovmf_table, ptr - tot_len, tot_len);
177     ovmf_table += tot_len;
178 }
179 
180 bool pc_system_ovmf_table_find(const char *entry, uint8_t **data,
181                                int *data_len)
182 {
183     uint8_t *ptr = ovmf_table;
184     int tot_len = ovmf_table_len;
185     QemuUUID entry_guid;
186 
187     if (qemu_uuid_parse(entry, &entry_guid) < 0) {
188         return false;
189     }
190 
191     if (!ptr) {
192         return false;
193     }
194 
195     entry_guid = qemu_uuid_bswap(entry_guid); /* guids are LE */
196     while (tot_len >= sizeof(QemuUUID) + sizeof(uint16_t)) {
197         int len;
198         QemuUUID *guid;
199 
200         /*
201          * The data structure is
202          *   arbitrary length data
203          *   2 byte length of entire entry
204          *   16 byte guid
205          */
206         guid = (QemuUUID *)(ptr - sizeof(QemuUUID));
207         len = le16_to_cpu(*(uint16_t *)(ptr - sizeof(QemuUUID) -
208                                         sizeof(uint16_t)));
209 
210         /*
211          * just in case the table is corrupt, wouldn't want to spin in
212          * the zero case
213          */
214         if (len < sizeof(QemuUUID) + sizeof(uint16_t)) {
215             return false;
216         } else if (len > tot_len) {
217             return false;
218         }
219 
220         ptr -= len;
221         tot_len -= len;
222         if (qemu_uuid_is_equal(guid, &entry_guid)) {
223             if (data) {
224                 *data = ptr;
225             }
226             if (data_len) {
227                 *data_len = len - sizeof(QemuUUID) - sizeof(uint16_t);
228             }
229             return true;
230         }
231     }
232     return false;
233 }
234 
235 /*
236  * Map the pcms->flash[] from 4GiB downward, and realize.
237  * Map them in descending order, i.e. pcms->flash[0] at the top,
238  * without gaps.
239  * Stop at the first pcms->flash[0] lacking a block backend.
240  * Set each flash's size from its block backend.  Fatal error if the
241  * size isn't a non-zero multiple of 4KiB, or the total size exceeds
242  * pcms->max_fw_size.
243  *
244  * If pcms->flash[0] has a block backend, its memory is passed to
245  * pc_isa_bios_init().  Merging several flash devices for isa-bios is
246  * not supported.
247  */
248 static void pc_system_flash_map(PCMachineState *pcms,
249                                 MemoryRegion *rom_memory)
250 {
251     hwaddr total_size = 0;
252     int i;
253     BlockBackend *blk;
254     int64_t size;
255     PFlashCFI01 *system_flash;
256     MemoryRegion *flash_mem;
257     void *flash_ptr;
258     int flash_size;
259     int ret;
260 
261     assert(PC_MACHINE_GET_CLASS(pcms)->pci_enabled);
262 
263     for (i = 0; i < ARRAY_SIZE(pcms->flash); i++) {
264         system_flash = pcms->flash[i];
265         blk = pflash_cfi01_get_blk(system_flash);
266         if (!blk) {
267             break;
268         }
269         size = blk_getlength(blk);
270         if (size < 0) {
271             error_report("can't get size of block device %s: %s",
272                          blk_name(blk), strerror(-size));
273             exit(1);
274         }
275         if (size == 0 || !QEMU_IS_ALIGNED(size, FLASH_SECTOR_SIZE)) {
276             error_report("system firmware block device %s has invalid size "
277                          "%" PRId64,
278                          blk_name(blk), size);
279             info_report("its size must be a non-zero multiple of 0x%x",
280                         FLASH_SECTOR_SIZE);
281             exit(1);
282         }
283         if ((hwaddr)size != size
284             || total_size > HWADDR_MAX - size
285             || total_size + size > pcms->max_fw_size) {
286             error_report("combined size of system firmware exceeds "
287                          "%" PRIu64 " bytes",
288                          pcms->max_fw_size);
289             exit(1);
290         }
291 
292         total_size += size;
293         qdev_prop_set_uint32(DEVICE(system_flash), "num-blocks",
294                              size / FLASH_SECTOR_SIZE);
295         sysbus_realize_and_unref(SYS_BUS_DEVICE(system_flash), &error_fatal);
296         sysbus_mmio_map(SYS_BUS_DEVICE(system_flash), 0,
297                         0x100000000ULL - total_size);
298 
299         if (i == 0) {
300             flash_mem = pflash_cfi01_get_memory(system_flash);
301             pc_isa_bios_init(rom_memory, flash_mem, size);
302 
303             /* Encrypt the pflash boot ROM */
304             if (sev_enabled()) {
305                 flash_ptr = memory_region_get_ram_ptr(flash_mem);
306                 flash_size = memory_region_size(flash_mem);
307                 /*
308                  * OVMF places a GUIDed structures in the flash, so
309                  * search for them
310                  */
311                 pc_system_parse_ovmf_flash(flash_ptr, flash_size);
312 
313                 ret = sev_es_save_reset_vector(flash_ptr, flash_size);
314                 if (ret) {
315                     error_report("failed to locate and/or save reset vector");
316                     exit(1);
317                 }
318 
319                 sev_encrypt_flash(flash_ptr, flash_size, &error_fatal);
320             }
321         }
322     }
323 }
324 
325 void pc_system_firmware_init(PCMachineState *pcms,
326                              MemoryRegion *rom_memory)
327 {
328     PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
329     int i;
330     BlockBackend *pflash_blk[ARRAY_SIZE(pcms->flash)];
331 
332     if (!pcmc->pci_enabled) {
333         x86_bios_rom_init(MACHINE(pcms), "bios.bin", rom_memory, true);
334         return;
335     }
336 
337     /* Map legacy -drive if=pflash to machine properties */
338     for (i = 0; i < ARRAY_SIZE(pcms->flash); i++) {
339         pflash_cfi01_legacy_drive(pcms->flash[i],
340                                   drive_get(IF_PFLASH, 0, i));
341         pflash_blk[i] = pflash_cfi01_get_blk(pcms->flash[i]);
342     }
343 
344     /* Reject gaps */
345     for (i = 1; i < ARRAY_SIZE(pcms->flash); i++) {
346         if (pflash_blk[i] && !pflash_blk[i - 1]) {
347             error_report("pflash%d requires pflash%d", i, i - 1);
348             exit(1);
349         }
350     }
351 
352     if (!pflash_blk[0]) {
353         /* Machine property pflash0 not set, use ROM mode */
354         x86_bios_rom_init(MACHINE(pcms), "bios.bin", rom_memory, false);
355     } else {
356         if (kvm_enabled() && !kvm_readonly_mem_enabled()) {
357             /*
358              * Older KVM cannot execute from device memory. So, flash
359              * memory cannot be used unless the readonly memory kvm
360              * capability is present.
361              */
362             error_report("pflash with kvm requires KVM readonly memory support");
363             exit(1);
364         }
365 
366         pc_system_flash_map(pcms, rom_memory);
367     }
368 
369     pc_system_flash_cleanup_unused(pcms);
370 }
371