1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2004 Christian Limpach.
5 * Copyright (c) 2004-2006,2008 Kip Macy
6 * Copyright (c) 2008 The NetBSD Foundation, Inc.
7 * Copyright (c) 2013 Roger Pau Monné <roger.pau@citrix.com>
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #include "opt_ddb.h"
34 #include "opt_kstack_pages.h"
35
36 #include <sys/param.h>
37 #include <sys/bus.h>
38 #include <sys/kernel.h>
39 #include <sys/reboot.h>
40 #include <sys/systm.h>
41 #include <sys/malloc.h>
42 #include <sys/linker.h>
43 #include <sys/lock.h>
44 #include <sys/rwlock.h>
45 #include <sys/boot.h>
46 #include <sys/ctype.h>
47 #include <sys/mutex.h>
48 #include <sys/smp.h>
49 #include <sys/efi.h>
50 #include <sys/tslog.h>
51
52 #include <vm/vm.h>
53 #include <vm/vm_extern.h>
54 #include <vm/vm_kern.h>
55 #include <vm/vm_page.h>
56 #include <vm/vm_map.h>
57 #include <vm/vm_object.h>
58 #include <vm/vm_pager.h>
59 #include <vm/vm_param.h>
60
61 #include <machine/_inttypes.h>
62 #include <machine/intr_machdep.h>
63 #include <x86/apicvar.h>
64 #include <x86/init.h>
65 #include <machine/pc/bios.h>
66 #include <machine/smp.h>
67 #include <machine/intr_machdep.h>
68 #include <machine/md_var.h>
69 #include <machine/metadata.h>
70 #include <machine/cpu.h>
71
72 #include <xen/xen-os.h>
73 #include <xen/hvm.h>
74 #include <xen/hypervisor.h>
75 #include <xen/xenstore/xenstorevar.h>
76 #include <xen/xen_pv.h>
77
78 #include <contrib/xen/arch-x86/cpuid.h>
79 #include <contrib/xen/arch-x86/hvm/start_info.h>
80 #include <contrib/xen/vcpu.h>
81
82 #include <dev/xen/timer/timer.h>
83
84 #ifdef DDB
85 #include <ddb/ddb.h>
86 #endif
87
88 /* Native initial function */
89 extern u_int64_t hammer_time(u_int64_t, u_int64_t);
90 /* Xen initial function */
91 uint64_t hammer_time_xen(vm_paddr_t);
92
93 #define MAX_E820_ENTRIES 128
94
95 /*--------------------------- Forward Declarations ---------------------------*/
96 static caddr_t xen_pvh_parse_preload_data(uint64_t);
97 static void pvh_parse_memmap(caddr_t, vm_paddr_t *, int *);
98
99 /*---------------------------- Extern Declarations ---------------------------*/
100 /*
101 * Placed by the linker at the end of the bss section, which is the last
102 * section loaded by Xen before loading the symtab and strtab.
103 */
104 extern uint32_t end;
105
106 /*-------------------------------- Global Data -------------------------------*/
107 struct init_ops xen_pvh_init_ops = {
108 .parse_preload_data = xen_pvh_parse_preload_data,
109 .early_clock_source_init = xen_clock_init,
110 .early_delay = xen_delay,
111 .parse_memmap = pvh_parse_memmap,
112 };
113
114 static struct bios_smap xen_smap[MAX_E820_ENTRIES];
115
116 static struct hvm_start_info *start_info;
117
118 /*-------------------------------- Xen PV init -------------------------------*/
119
120 static int
isxen(void)121 isxen(void)
122 {
123 static int xen = -1;
124 uint32_t base;
125 u_int regs[4];
126
127 if (xen != -1)
128 return (xen);
129
130 /*
131 * The full code for identifying which hypervisor we're running under
132 * is in sys/x86/x86/identcpu.c and runs later in the boot process;
133 * this is sufficient to distinguish Xen PVH booting from non-Xen PVH
134 * and skip some very early Xen-specific code in the non-Xen case.
135 */
136 xen = 0;
137 for (base = 0x40000000; base < 0x40010000; base += 0x100) {
138 do_cpuid(base, regs);
139 if (regs[1] == XEN_CPUID_SIGNATURE_EBX &&
140 regs[2] == XEN_CPUID_SIGNATURE_ECX &&
141 regs[3] == XEN_CPUID_SIGNATURE_EDX) {
142 xen = 1;
143 break;
144 }
145 }
146 return (xen);
147 }
148
149 #define CRASH(...) do { \
150 if (isxen()) \
151 xc_printf(__VA_ARGS__); \
152 halt(); \
153 } while (0)
154
155 uint64_t
hammer_time_xen(vm_paddr_t start_info_paddr)156 hammer_time_xen(vm_paddr_t start_info_paddr)
157 {
158 struct hvm_modlist_entry *mod;
159 uint64_t physfree;
160 char *kenv;
161
162 start_info = (struct hvm_start_info *)(start_info_paddr + KERNBASE);
163 if (start_info->magic != XEN_HVM_START_MAGIC_VALUE) {
164 CRASH("Unknown magic value in start_info struct: %#x\n",
165 start_info->magic);
166 }
167
168 /*
169 * Select the higher address to use as physfree: either after
170 * start_info, after the kernel, after the memory map or after any of
171 * the modules. We assume enough memory to be available after the
172 * selected address for the needs of very early memory allocations.
173 */
174 physfree = roundup2(start_info_paddr + sizeof(struct hvm_start_info),
175 PAGE_SIZE);
176 physfree = MAX(roundup2((vm_paddr_t)_end - KERNBASE, PAGE_SIZE),
177 physfree);
178
179 if (start_info->memmap_paddr != 0)
180 physfree = MAX(roundup2(start_info->memmap_paddr +
181 start_info->memmap_entries *
182 sizeof(struct hvm_memmap_table_entry), PAGE_SIZE),
183 physfree);
184
185 if (start_info->modlist_paddr != 0) {
186 unsigned int i;
187
188 if (start_info->nr_modules == 0) {
189 CRASH(
190 "ERROR: modlist_paddr != 0 but nr_modules == 0\n");
191 }
192 mod = (struct hvm_modlist_entry *)
193 (start_info->modlist_paddr + KERNBASE);
194 for (i = 0; i < start_info->nr_modules; i++)
195 physfree = MAX(roundup2(mod[i].paddr + mod[i].size,
196 PAGE_SIZE), physfree);
197 }
198
199 /*
200 * Init a static kenv using a free page. The contents will be filled
201 * from the parse_preload_data hook.
202 */
203 kenv = (void *)(physfree + KERNBASE);
204 physfree += PAGE_SIZE;
205 bzero_early(kenv, PAGE_SIZE);
206 init_static_kenv(kenv, PAGE_SIZE);
207
208 /* Set the hooks for early functions that diverge from bare metal */
209 init_ops = xen_pvh_init_ops;
210 hvm_start_flags = start_info->flags;
211
212 /* Now we can jump into the native init function */
213 return (hammer_time(0, physfree));
214 }
215
216 /*-------------------------------- PV specific -------------------------------*/
217
218 /*
219 * When booted as a PVH guest FreeBSD needs to avoid using the RSDP address
220 * hint provided by the loader because it points to the native set of ACPI
221 * tables instead of the ones crafted by Xen. The acpi.rsdp env variable is
222 * removed from kenv if present, and a new acpi.rsdp is added to kenv that
223 * points to the address of the Xen crafted RSDP.
224 */
reject_option(const char * option)225 static bool reject_option(const char *option)
226 {
227 static const char *reject[] = {
228 "acpi.rsdp",
229 };
230 unsigned int i;
231
232 for (i = 0; i < nitems(reject); i++)
233 if (strncmp(option, reject[i], strlen(reject[i])) == 0)
234 return (true);
235
236 return (false);
237 }
238
239 static void
xen_pvh_set_env(char * env,bool (* filter)(const char *))240 xen_pvh_set_env(char *env, bool (*filter)(const char *))
241 {
242 char *option;
243
244 if (env == NULL)
245 return;
246
247 option = env;
248 while (*option != 0) {
249 char *value;
250
251 if (filter != NULL && filter(option)) {
252 option += strlen(option) + 1;
253 continue;
254 }
255
256 value = option;
257 option = strsep(&value, "=");
258 if (kern_setenv(option, value) != 0 && isxen())
259 xc_printf("unable to add kenv %s=%s\n", option, value);
260 option = value + strlen(value) + 1;
261 }
262 }
263
264 #ifdef DDB
265 /*
266 * The way Xen loads the symtab is different from the native boot loader,
267 * because it's tailored for NetBSD. So we have to adapt and use the same
268 * method as NetBSD. Portions of the code below have been picked from NetBSD:
269 * sys/kern/kern_ksyms.c CVS Revision 1.71.
270 */
271 static void
xen_pvh_parse_symtab(void)272 xen_pvh_parse_symtab(void)
273 {
274 Elf_Ehdr *ehdr;
275 Elf_Shdr *shdr;
276 int i, j;
277
278 ehdr = (Elf_Ehdr *)(&end + 1);
279 if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) ||
280 ehdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
281 ehdr->e_version > 1) {
282 if (isxen())
283 xc_printf("Unable to load ELF symtab: invalid symbol table\n");
284 return;
285 }
286
287 shdr = (Elf_Shdr *)((uint8_t *)ehdr + ehdr->e_shoff);
288 /* Find the symbol table and the corresponding string table. */
289 for (i = 1; i < ehdr->e_shnum; i++) {
290 if (shdr[i].sh_type != SHT_SYMTAB)
291 continue;
292 if (shdr[i].sh_offset == 0)
293 continue;
294 ksymtab = (uintptr_t)((uint8_t *)ehdr + shdr[i].sh_offset);
295 ksymtab_size = shdr[i].sh_size;
296 j = shdr[i].sh_link;
297 if (shdr[j].sh_offset == 0)
298 continue; /* Can this happen? */
299 kstrtab = (uintptr_t)((uint8_t *)ehdr + shdr[j].sh_offset);
300 break;
301 }
302
303 if ((ksymtab == 0 || kstrtab == 0) && isxen())
304 xc_printf(
305 "Unable to load ELF symtab: could not find symtab or strtab\n");
306 }
307 #endif
308
309 static caddr_t
xen_pvh_parse_preload_data(uint64_t modulep)310 xen_pvh_parse_preload_data(uint64_t modulep)
311 {
312 caddr_t kmdp;
313 vm_ooffset_t off;
314 vm_paddr_t metadata;
315 char *envp;
316 char acpi_rsdp[19];
317
318 TSENTER();
319 if (start_info->modlist_paddr != 0) {
320 struct hvm_modlist_entry *mod;
321 const char *cmdline;
322
323 mod = (struct hvm_modlist_entry *)
324 (start_info->modlist_paddr + KERNBASE);
325 cmdline = mod[0].cmdline_paddr ?
326 (const char *)(mod[0].cmdline_paddr + KERNBASE) : NULL;
327
328 if (strcmp(cmdline, "header") == 0) {
329 struct xen_header *header;
330
331 header = (struct xen_header *)(mod[0].paddr + KERNBASE);
332
333 if ((header->flags & XENHEADER_HAS_MODULEP_OFFSET) !=
334 XENHEADER_HAS_MODULEP_OFFSET) {
335 xc_printf("Unable to load module metadata\n");
336 HYPERVISOR_shutdown(SHUTDOWN_crash);
337 }
338
339 preload_metadata = (caddr_t)(mod[0].paddr +
340 header->modulep_offset + KERNBASE);
341
342 kmdp = preload_search_by_type("elf kernel");
343 if (kmdp == NULL)
344 kmdp = preload_search_by_type("elf64 kernel");
345 if (kmdp == NULL) {
346 xc_printf("Unable to find kernel\n");
347 HYPERVISOR_shutdown(SHUTDOWN_crash);
348 }
349
350 /*
351 * Xen has relocated the metadata and the modules, so
352 * we need to recalculate it's position. This is done
353 * by saving the original modulep address and then
354 * calculating the offset from the real modulep
355 * position.
356 */
357 metadata = MD_FETCH(kmdp, MODINFOMD_MODULEP,
358 vm_paddr_t);
359 off = mod[0].paddr + header->modulep_offset - metadata +
360 KERNBASE;
361 } else {
362 preload_metadata = (caddr_t)(mod[0].paddr + KERNBASE);
363
364 kmdp = preload_search_by_type("elf kernel");
365 if (kmdp == NULL)
366 kmdp = preload_search_by_type("elf64 kernel");
367 if (kmdp == NULL) {
368 xc_printf("Unable to find kernel\n");
369 HYPERVISOR_shutdown(SHUTDOWN_crash);
370 }
371
372 metadata = MD_FETCH(kmdp, MODINFOMD_MODULEP, vm_paddr_t);
373 off = mod[0].paddr + KERNBASE - metadata;
374 }
375
376 preload_bootstrap_relocate(off);
377
378 boothowto = MD_FETCH(kmdp, MODINFOMD_HOWTO, int);
379 envp = MD_FETCH(kmdp, MODINFOMD_ENVP, char *);
380 if (envp != NULL)
381 envp += off;
382 xen_pvh_set_env(envp, reject_option);
383
384 if (MD_FETCH(kmdp, MODINFOMD_EFI_MAP, void *) != NULL)
385 strlcpy(bootmethod, "UEFI", sizeof(bootmethod));
386 else
387 strlcpy(bootmethod, "BIOS", sizeof(bootmethod));
388 } else {
389 /* Parse the extra boot information given by Xen */
390 if (start_info->cmdline_paddr != 0)
391 boot_parse_cmdline_delim(
392 (char *)(start_info->cmdline_paddr + KERNBASE),
393 ", \t\n");
394 kmdp = NULL;
395 strlcpy(bootmethod, "PVH", sizeof(bootmethod));
396 }
397
398 boothowto |= boot_env_to_howto();
399
400 snprintf(acpi_rsdp, sizeof(acpi_rsdp), "%#" PRIx64,
401 start_info->rsdp_paddr);
402 kern_setenv("acpi.rsdp", acpi_rsdp);
403
404 #ifdef DDB
405 xen_pvh_parse_symtab();
406 #endif
407 TSEXIT();
408 return (kmdp);
409 }
410
411 static void
pvh_parse_memmap_start_info(caddr_t kmdp,vm_paddr_t * physmap,int * physmap_idx)412 pvh_parse_memmap_start_info(caddr_t kmdp, vm_paddr_t *physmap,
413 int *physmap_idx)
414 {
415 const struct hvm_memmap_table_entry * entries;
416 size_t nentries;
417 size_t i;
418
419 /* Extract from HVM start_info. */
420 entries = (struct hvm_memmap_table_entry *)(start_info->memmap_paddr + KERNBASE);
421 nentries = start_info->memmap_entries;
422
423 /* Convert into E820 format and handle one by one. */
424 for (i = 0; i < nentries; i++) {
425 struct bios_smap entry;
426
427 entry.base = entries[i].addr;
428 entry.length = entries[i].size;
429
430 /*
431 * Luckily for us, the XEN_HVM_MEMMAP_TYPE_* values exactly
432 * match the SMAP_TYPE_* values so we don't need to translate
433 * anything here.
434 */
435 entry.type = entries[i].type;
436
437 bios_add_smap_entries(&entry, 1, physmap, physmap_idx);
438 }
439 }
440
441 static void
xen_pvh_parse_memmap(caddr_t kmdp,vm_paddr_t * physmap,int * physmap_idx)442 xen_pvh_parse_memmap(caddr_t kmdp, vm_paddr_t *physmap, int *physmap_idx)
443 {
444 struct xen_memory_map memmap;
445 u_int32_t size;
446 int rc;
447
448 /* We should only reach here if we're running under Xen. */
449 KASSERT(isxen(), ("xen_pvh_parse_memmap reached when !Xen"));
450
451 /* Fetch the E820 map from Xen */
452 memmap.nr_entries = MAX_E820_ENTRIES;
453 set_xen_guest_handle(memmap.buffer, xen_smap);
454 rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
455 if (rc) {
456 xc_printf("ERROR: unable to fetch Xen E820 memory map: %d\n",
457 rc);
458 HYPERVISOR_shutdown(SHUTDOWN_crash);
459 }
460
461 size = memmap.nr_entries * sizeof(xen_smap[0]);
462
463 bios_add_smap_entries(xen_smap, size, physmap, physmap_idx);
464 }
465
466 static void
pvh_parse_memmap(caddr_t kmdp,vm_paddr_t * physmap,int * physmap_idx)467 pvh_parse_memmap(caddr_t kmdp, vm_paddr_t *physmap, int *physmap_idx)
468 {
469
470 /*
471 * If version >= 1 and memmap_paddr != 0, use the memory map provided
472 * in the start_info structure; if not, we're running under legacy
473 * Xen and need to use the Xen hypercall.
474 */
475 if ((start_info->version >= 1) && (start_info->memmap_paddr != 0))
476 pvh_parse_memmap_start_info(kmdp, physmap, physmap_idx);
477 else
478 xen_pvh_parse_memmap(kmdp, physmap, physmap_idx);
479 }
480