xref: /openbmc/qemu/hw/i386/pc_sysfw.c (revision ac12b601)
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 "hw/block/flash.h"
39 #include "sysemu/kvm.h"
40 #include "sysemu/sev.h"
41 
42 #define FLASH_SECTOR_SIZE 4096
43 
44 static void pc_isa_bios_init(MemoryRegion *rom_memory,
45                              MemoryRegion *flash_mem,
46                              int ram_size)
47 {
48     int isa_bios_size;
49     MemoryRegion *isa_bios;
50     uint64_t flash_size;
51     void *flash_ptr, *isa_bios_ptr;
52 
53     flash_size = memory_region_size(flash_mem);
54 
55     /* map the last 128KB of the BIOS in ISA space */
56     isa_bios_size = MIN(flash_size, 128 * KiB);
57     isa_bios = g_malloc(sizeof(*isa_bios));
58     memory_region_init_ram(isa_bios, NULL, "isa-bios", isa_bios_size,
59                            &error_fatal);
60     memory_region_add_subregion_overlap(rom_memory,
61                                         0x100000 - isa_bios_size,
62                                         isa_bios,
63                                         1);
64 
65     /* copy ISA rom image from top of flash memory */
66     flash_ptr = memory_region_get_ram_ptr(flash_mem);
67     isa_bios_ptr = memory_region_get_ram_ptr(isa_bios);
68     memcpy(isa_bios_ptr,
69            ((uint8_t*)flash_ptr) + (flash_size - isa_bios_size),
70            isa_bios_size);
71 
72     memory_region_set_readonly(isa_bios, true);
73 }
74 
75 static PFlashCFI01 *pc_pflash_create(PCMachineState *pcms,
76                                      const char *name,
77                                      const char *alias_prop_name)
78 {
79     DeviceState *dev = qdev_new(TYPE_PFLASH_CFI01);
80 
81     qdev_prop_set_uint64(dev, "sector-length", FLASH_SECTOR_SIZE);
82     qdev_prop_set_uint8(dev, "width", 1);
83     qdev_prop_set_string(dev, "name", name);
84     object_property_add_child(OBJECT(pcms), name, OBJECT(dev));
85     object_property_add_alias(OBJECT(pcms), alias_prop_name,
86                               OBJECT(dev), "drive");
87     /*
88      * The returned reference is tied to the child property and
89      * will be removed with object_unparent.
90      */
91     object_unref(OBJECT(dev));
92     return PFLASH_CFI01(dev);
93 }
94 
95 void pc_system_flash_create(PCMachineState *pcms)
96 {
97     PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
98 
99     if (pcmc->pci_enabled) {
100         pcms->flash[0] = pc_pflash_create(pcms, "system.flash0",
101                                           "pflash0");
102         pcms->flash[1] = pc_pflash_create(pcms, "system.flash1",
103                                           "pflash1");
104     }
105 }
106 
107 void pc_system_flash_cleanup_unused(PCMachineState *pcms)
108 {
109     char *prop_name;
110     int i;
111     Object *dev_obj;
112 
113     assert(PC_MACHINE_GET_CLASS(pcms)->pci_enabled);
114 
115     for (i = 0; i < ARRAY_SIZE(pcms->flash); i++) {
116         dev_obj = OBJECT(pcms->flash[i]);
117         if (!object_property_get_bool(dev_obj, "realized", &error_abort)) {
118             prop_name = g_strdup_printf("pflash%d", i);
119             object_property_del(OBJECT(pcms), prop_name);
120             g_free(prop_name);
121             object_unparent(dev_obj);
122             pcms->flash[i] = NULL;
123         }
124     }
125 }
126 
127 #define OVMF_TABLE_FOOTER_GUID "96b582de-1fb2-45f7-baea-a366c55a082d"
128 
129 static uint8_t *ovmf_table;
130 static int ovmf_table_len;
131 
132 static void pc_system_parse_ovmf_flash(uint8_t *flash_ptr, size_t flash_size)
133 {
134     uint8_t *ptr;
135     QemuUUID guid;
136     int tot_len;
137 
138     /* should only be called once */
139     if (ovmf_table) {
140         return;
141     }
142 
143     if (flash_size < TARGET_PAGE_SIZE) {
144         return;
145     }
146 
147     /*
148      * if this is OVMF there will be a table footer
149      * guid 48 bytes before the end of the flash file.  If it's
150      * not found, silently abort the flash parsing.
151      */
152     qemu_uuid_parse(OVMF_TABLE_FOOTER_GUID, &guid);
153     guid = qemu_uuid_bswap(guid); /* guids are LE */
154     ptr = flash_ptr + flash_size - 48;
155     if (!qemu_uuid_is_equal((QemuUUID *)ptr, &guid)) {
156         return;
157     }
158 
159     /* if found, just before is two byte table length */
160     ptr -= sizeof(uint16_t);
161     tot_len = le16_to_cpu(*(uint16_t *)ptr) - sizeof(guid) - sizeof(uint16_t);
162 
163     if (tot_len <= 0) {
164         return;
165     }
166 
167     ovmf_table = g_malloc(tot_len);
168     ovmf_table_len = tot_len;
169 
170     /*
171      * ptr is the foot of the table, so copy it all to the newly
172      * allocated ovmf_table and then set the ovmf_table pointer
173      * to the table foot
174      */
175     memcpy(ovmf_table, ptr - tot_len, tot_len);
176     ovmf_table += tot_len;
177 }
178 
179 bool pc_system_ovmf_table_find(const char *entry, uint8_t **data,
180                                int *data_len)
181 {
182     uint8_t *ptr = ovmf_table;
183     int tot_len = ovmf_table_len;
184     QemuUUID entry_guid;
185 
186     if (qemu_uuid_parse(entry, &entry_guid) < 0) {
187         return false;
188     }
189 
190     if (!ptr) {
191         return false;
192     }
193 
194     entry_guid = qemu_uuid_bswap(entry_guid); /* guids are LE */
195     while (tot_len >= sizeof(QemuUUID) + sizeof(uint16_t)) {
196         int len;
197         QemuUUID *guid;
198 
199         /*
200          * The data structure is
201          *   arbitrary length data
202          *   2 byte length of entire entry
203          *   16 byte guid
204          */
205         guid = (QemuUUID *)(ptr - sizeof(QemuUUID));
206         len = le16_to_cpu(*(uint16_t *)(ptr - sizeof(QemuUUID) -
207                                         sizeof(uint16_t)));
208 
209         /*
210          * just in case the table is corrupt, wouldn't want to spin in
211          * the zero case
212          */
213         if (len < sizeof(QemuUUID) + sizeof(uint16_t)) {
214             return false;
215         } else if (len > tot_len) {
216             return false;
217         }
218 
219         ptr -= len;
220         tot_len -= len;
221         if (qemu_uuid_is_equal(guid, &entry_guid)) {
222             if (data) {
223                 *data = ptr;
224             }
225             if (data_len) {
226                 *data_len = len - sizeof(QemuUUID) - sizeof(uint16_t);
227             }
228             return true;
229         }
230     }
231     return false;
232 }
233 
234 /*
235  * Map the pcms->flash[] from 4GiB downward, and realize.
236  * Map them in descending order, i.e. pcms->flash[0] at the top,
237  * without gaps.
238  * Stop at the first pcms->flash[0] lacking a block backend.
239  * Set each flash's size from its block backend.  Fatal error if the
240  * size isn't a non-zero multiple of 4KiB, or the total size exceeds
241  * pcms->max_fw_size.
242  *
243  * If pcms->flash[0] has a block backend, its memory is passed to
244  * pc_isa_bios_init().  Merging several flash devices for isa-bios is
245  * not supported.
246  */
247 static void pc_system_flash_map(PCMachineState *pcms,
248                                 MemoryRegion *rom_memory)
249 {
250     hwaddr total_size = 0;
251     int i;
252     BlockBackend *blk;
253     int64_t size;
254     PFlashCFI01 *system_flash;
255     MemoryRegion *flash_mem;
256     void *flash_ptr;
257     int flash_size;
258     int ret;
259 
260     assert(PC_MACHINE_GET_CLASS(pcms)->pci_enabled);
261 
262     for (i = 0; i < ARRAY_SIZE(pcms->flash); i++) {
263         system_flash = pcms->flash[i];
264         blk = pflash_cfi01_get_blk(system_flash);
265         if (!blk) {
266             break;
267         }
268         size = blk_getlength(blk);
269         if (size < 0) {
270             error_report("can't get size of block device %s: %s",
271                          blk_name(blk), strerror(-size));
272             exit(1);
273         }
274         if (size == 0 || !QEMU_IS_ALIGNED(size, FLASH_SECTOR_SIZE)) {
275             error_report("system firmware block device %s has invalid size "
276                          "%" PRId64,
277                          blk_name(blk), size);
278             info_report("its size must be a non-zero multiple of 0x%x",
279                         FLASH_SECTOR_SIZE);
280             exit(1);
281         }
282         if ((hwaddr)size != size
283             || total_size > HWADDR_MAX - size
284             || total_size + size > pcms->max_fw_size) {
285             error_report("combined size of system firmware exceeds "
286                          "%" PRIu64 " bytes",
287                          pcms->max_fw_size);
288             exit(1);
289         }
290 
291         total_size += size;
292         qdev_prop_set_uint32(DEVICE(system_flash), "num-blocks",
293                              size / FLASH_SECTOR_SIZE);
294         sysbus_realize_and_unref(SYS_BUS_DEVICE(system_flash), &error_fatal);
295         sysbus_mmio_map(SYS_BUS_DEVICE(system_flash), 0,
296                         0x100000000ULL - total_size);
297 
298         if (i == 0) {
299             flash_mem = pflash_cfi01_get_memory(system_flash);
300             pc_isa_bios_init(rom_memory, flash_mem, size);
301 
302             /* Encrypt the pflash boot ROM */
303             if (sev_enabled()) {
304                 flash_ptr = memory_region_get_ram_ptr(flash_mem);
305                 flash_size = memory_region_size(flash_mem);
306                 /*
307                  * OVMF places a GUIDed structures in the flash, so
308                  * search for them
309                  */
310                 pc_system_parse_ovmf_flash(flash_ptr, flash_size);
311 
312                 ret = sev_es_save_reset_vector(flash_ptr, flash_size);
313                 if (ret) {
314                     error_report("failed to locate and/or save reset vector");
315                     exit(1);
316                 }
317 
318                 sev_encrypt_flash(flash_ptr, flash_size, &error_fatal);
319             }
320         }
321     }
322 }
323 
324 void pc_system_firmware_init(PCMachineState *pcms,
325                              MemoryRegion *rom_memory)
326 {
327     PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
328     int i;
329     BlockBackend *pflash_blk[ARRAY_SIZE(pcms->flash)];
330 
331     if (!pcmc->pci_enabled) {
332         x86_bios_rom_init(MACHINE(pcms), "bios.bin", rom_memory, true);
333         return;
334     }
335 
336     /* Map legacy -drive if=pflash to machine properties */
337     for (i = 0; i < ARRAY_SIZE(pcms->flash); i++) {
338         pflash_cfi01_legacy_drive(pcms->flash[i],
339                                   drive_get(IF_PFLASH, 0, i));
340         pflash_blk[i] = pflash_cfi01_get_blk(pcms->flash[i]);
341     }
342 
343     /* Reject gaps */
344     for (i = 1; i < ARRAY_SIZE(pcms->flash); i++) {
345         if (pflash_blk[i] && !pflash_blk[i - 1]) {
346             error_report("pflash%d requires pflash%d", i, i - 1);
347             exit(1);
348         }
349     }
350 
351     if (!pflash_blk[0]) {
352         /* Machine property pflash0 not set, use ROM mode */
353         x86_bios_rom_init(MACHINE(pcms), "bios.bin", rom_memory, false);
354     } else {
355         if (kvm_enabled() && !kvm_readonly_mem_enabled()) {
356             /*
357              * Older KVM cannot execute from device memory. So, flash
358              * memory cannot be used unless the readonly memory kvm
359              * capability is present.
360              */
361             error_report("pflash with kvm requires KVM readonly memory support");
362             exit(1);
363         }
364 
365         pc_system_flash_map(pcms, rom_memory);
366     }
367 
368     pc_system_flash_cleanup_unused(pcms);
369 }
370