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1/*
2 * Machine specific setup for xen
3 *
4 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
5 */
6
7#include <linux/module.h>
8#include <linux/sched.h>
9#include <linux/mm.h>
10#include <linux/pm.h>
11#include <linux/memblock.h>
12#include <linux/cpuidle.h>
13
14#include <asm/elf.h>
15#include <asm/vdso.h>
16#include <asm/e820.h>
17#include <asm/setup.h>
18#include <asm/acpi.h>
19#include <asm/xen/hypervisor.h>
20#include <asm/xen/hypercall.h>
21
22#include <xen/xen.h>
23#include <xen/page.h>
24#include <xen/interface/callback.h>
25#include <xen/interface/memory.h>
26#include <xen/interface/physdev.h>
27#include <xen/features.h>
28
29#include "xen-ops.h"
30#include "vdso.h"
31
32/* These are code, but not functions. Defined in entry.S */
33extern const char xen_hypervisor_callback[];
34extern const char xen_failsafe_callback[];
35extern void xen_sysenter_target(void);
36extern void xen_syscall_target(void);
37extern void xen_syscall32_target(void);
38
39/* Amount of extra memory space we add to the e820 ranges */
40phys_addr_t xen_extra_mem_start, xen_extra_mem_size;
41
42/*
43 * The maximum amount of extra memory compared to the base size. The
44 * main scaling factor is the size of struct page. At extreme ratios
45 * of base:extra, all the base memory can be filled with page
46 * structures for the extra memory, leaving no space for anything
47 * else.
48 *
49 * 10x seems like a reasonable balance between scaling flexibility and
50 * leaving a practically usable system.
51 */
52#define EXTRA_MEM_RATIO (10)
53
54static void __init xen_add_extra_mem(unsigned long pages)
55{
56 unsigned long pfn;
57
58 u64 size = (u64)pages * PAGE_SIZE;
59 u64 extra_start = xen_extra_mem_start + xen_extra_mem_size;
60
61 if (!pages)
62 return;
63
64 e820_add_region(extra_start, size, E820_RAM);
65 sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
66
67 memblock_x86_reserve_range(extra_start, extra_start + size, "XEN EXTRA");
68
69 xen_extra_mem_size += size;
70
71 xen_max_p2m_pfn = PFN_DOWN(extra_start + size);
72
73 for (pfn = PFN_DOWN(extra_start); pfn <= xen_max_p2m_pfn; pfn++)
74 __set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
75}
76
77static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
78 phys_addr_t end_addr)
79{
80 struct xen_memory_reservation reservation = {
81 .address_bits = 0,
82 .extent_order = 0,
83 .domid = DOMID_SELF
84 };
85 unsigned long start, end;
86 unsigned long len = 0;
87 unsigned long pfn;
88 int ret;
89
90 start = PFN_UP(start_addr);
91 end = PFN_DOWN(end_addr);
92
93 if (end <= start)
94 return 0;
95
96 for(pfn = start; pfn < end; pfn++) {
97 unsigned long mfn = pfn_to_mfn(pfn);
98
99 /* Make sure pfn exists to start with */
100 if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
101 continue;
102
103 set_xen_guest_handle(reservation.extent_start, &mfn);
104 reservation.nr_extents = 1;
105
106 ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
107 &reservation);
108 WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
109 if (ret == 1) {
110 __set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
111 len++;
112 }
113 }
114 printk(KERN_INFO "Freeing %lx-%lx pfn range: %lu pages freed\n",
115 start, end, len);
116
117 return len;
118}
119
120static unsigned long __init xen_return_unused_memory(unsigned long max_pfn,
121 const struct e820map *e820)
122{
123 phys_addr_t max_addr = PFN_PHYS(max_pfn);
124 phys_addr_t last_end = ISA_END_ADDRESS;
125 unsigned long released = 0;
126 int i;
127
128 /* Free any unused memory above the low 1Mbyte. */
129 for (i = 0; i < e820->nr_map && last_end < max_addr; i++) {
130 phys_addr_t end = e820->map[i].addr;
131 end = min(max_addr, end);
132
133 if (last_end < end)
134 released += xen_release_chunk(last_end, end);
135 last_end = max(last_end, e820->map[i].addr + e820->map[i].size);
136 }
137
138 if (last_end < max_addr)
139 released += xen_release_chunk(last_end, max_addr);
140
141 printk(KERN_INFO "released %lu pages of unused memory\n", released);
142 return released;
143}
144
145static unsigned long __init xen_set_identity(const struct e820entry *list,
146 ssize_t map_size)
147{
148 phys_addr_t last = xen_initial_domain() ? 0 : ISA_END_ADDRESS;
149 phys_addr_t start_pci = last;
150 const struct e820entry *entry;
151 unsigned long identity = 0;
152 int i;
153
154 for (i = 0, entry = list; i < map_size; i++, entry++) {
155 phys_addr_t start = entry->addr;
156 phys_addr_t end = start + entry->size;
157
158 if (start < last)
159 start = last;
160
161 if (end <= start)
162 continue;
163
164 /* Skip over the 1MB region. */
165 if (last > end)
166 continue;
167
168 if ((entry->type == E820_RAM) || (entry->type == E820_UNUSABLE)) {
169 if (start > start_pci)
170 identity += set_phys_range_identity(
171 PFN_UP(start_pci), PFN_DOWN(start));
172
173 /* Without saving 'last' we would gooble RAM too
174 * at the end of the loop. */
175 last = end;
176 start_pci = end;
177 continue;
178 }
179 start_pci = min(start, start_pci);
180 last = end;
181 }
182 if (last > start_pci)
183 identity += set_phys_range_identity(
184 PFN_UP(start_pci), PFN_DOWN(last));
185 return identity;
186}
187
188static unsigned long __init xen_get_max_pages(void)
189{
190 unsigned long max_pages = MAX_DOMAIN_PAGES;
191 domid_t domid = DOMID_SELF;
192 int ret;
193
194 ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
195 if (ret > 0)
196 max_pages = ret;
197 return min(max_pages, MAX_DOMAIN_PAGES);
198}
199
200/**
201 * machine_specific_memory_setup - Hook for machine specific memory setup.
202 **/
203char * __init xen_memory_setup(void)
204{
205 static struct e820entry map[E820MAX] __initdata;
206 static struct e820entry map_raw[E820MAX] __initdata;
207
208 unsigned long max_pfn = xen_start_info->nr_pages;
209 unsigned long long mem_end;
210 int rc;
211 struct xen_memory_map memmap;
212 unsigned long extra_pages = 0;
213 unsigned long extra_limit;
214 unsigned long identity_pages = 0;
215 int i;
216 int op;
217
218 max_pfn = min(MAX_DOMAIN_PAGES, max_pfn);
219 mem_end = PFN_PHYS(max_pfn);
220
221 memmap.nr_entries = E820MAX;
222 set_xen_guest_handle(memmap.buffer, map);
223
224 op = xen_initial_domain() ?
225 XENMEM_machine_memory_map :
226 XENMEM_memory_map;
227 rc = HYPERVISOR_memory_op(op, &memmap);
228 if (rc == -ENOSYS) {
229 BUG_ON(xen_initial_domain());
230 memmap.nr_entries = 1;
231 map[0].addr = 0ULL;
232 map[0].size = mem_end;
233 /* 8MB slack (to balance backend allocations). */
234 map[0].size += 8ULL << 20;
235 map[0].type = E820_RAM;
236 rc = 0;
237 }
238 BUG_ON(rc);
239
240 memcpy(map_raw, map, sizeof(map));
241 e820.nr_map = 0;
242 xen_extra_mem_start = mem_end;
243 for (i = 0; i < memmap.nr_entries; i++) {
244 unsigned long long end;
245
246 /* Guard against non-page aligned E820 entries. */
247 if (map[i].type == E820_RAM)
248 map[i].size -= (map[i].size + map[i].addr) % PAGE_SIZE;
249
250 end = map[i].addr + map[i].size;
251 if (map[i].type == E820_RAM && end > mem_end) {
252 /* RAM off the end - may be partially included */
253 u64 delta = min(map[i].size, end - mem_end);
254
255 map[i].size -= delta;
256 end -= delta;
257
258 extra_pages += PFN_DOWN(delta);
259 /*
260 * Set RAM below 4GB that is not for us to be unusable.
261 * This prevents "System RAM" address space from being
262 * used as potential resource for I/O address (happens
263 * when 'allocate_resource' is called).
264 */
265 if (delta &&
266 (xen_initial_domain() && end < 0x100000000ULL))
267 e820_add_region(end, delta, E820_UNUSABLE);
268 }
269
270 if (map[i].size > 0 && end > xen_extra_mem_start)
271 xen_extra_mem_start = end;
272
273 /* Add region if any remains */
274 if (map[i].size > 0)
275 e820_add_region(map[i].addr, map[i].size, map[i].type);
276 }
277 /* Align the balloon area so that max_low_pfn does not get set
278 * to be at the _end_ of the PCI gap at the far end (fee01000).
279 * Note that xen_extra_mem_start gets set in the loop above to be
280 * past the last E820 region. */
281 if (xen_initial_domain() && (xen_extra_mem_start < (1ULL<<32)))
282 xen_extra_mem_start = (1ULL<<32);
283
284 /*
285 * In domU, the ISA region is normal, usable memory, but we
286 * reserve ISA memory anyway because too many things poke
287 * about in there.
288 *
289 * In Dom0, the host E820 information can leave gaps in the
290 * ISA range, which would cause us to release those pages. To
291 * avoid this, we unconditionally reserve them here.
292 */
293 e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
294 E820_RESERVED);
295
296 /*
297 * Reserve Xen bits:
298 * - mfn_list
299 * - xen_start_info
300 * See comment above "struct start_info" in <xen/interface/xen.h>
301 */
302 memblock_x86_reserve_range(__pa(xen_start_info->mfn_list),
303 __pa(xen_start_info->pt_base),
304 "XEN START INFO");
305
306 sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
307
308 extra_limit = xen_get_max_pages();
309 if (max_pfn + extra_pages > extra_limit) {
310 if (extra_limit > max_pfn)
311 extra_pages = extra_limit - max_pfn;
312 else
313 extra_pages = 0;
314 }
315
316 extra_pages += xen_return_unused_memory(xen_start_info->nr_pages, &e820);
317
318 /*
319 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
320 * factor the base size. On non-highmem systems, the base
321 * size is the full initial memory allocation; on highmem it
322 * is limited to the max size of lowmem, so that it doesn't
323 * get completely filled.
324 *
325 * In principle there could be a problem in lowmem systems if
326 * the initial memory is also very large with respect to
327 * lowmem, but we won't try to deal with that here.
328 */
329 extra_limit = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
330 max_pfn + extra_pages);
331
332 if (extra_limit >= max_pfn)
333 extra_pages = extra_limit - max_pfn;
334 else
335 extra_pages = 0;
336
337 xen_add_extra_mem(extra_pages);
338
339 /*
340 * Set P2M for all non-RAM pages and E820 gaps to be identity
341 * type PFNs. We supply it with the non-sanitized version
342 * of the E820.
343 */
344 identity_pages = xen_set_identity(map_raw, memmap.nr_entries);
345 printk(KERN_INFO "Set %ld page(s) to 1-1 mapping.\n", identity_pages);
346 return "Xen";
347}
348
349/*
350 * Set the bit indicating "nosegneg" library variants should be used.
351 * We only need to bother in pure 32-bit mode; compat 32-bit processes
352 * can have un-truncated segments, so wrapping around is allowed.
353 */
354static void __init fiddle_vdso(void)
355{
356#ifdef CONFIG_X86_32
357 u32 *mask;
358 mask = VDSO32_SYMBOL(&vdso32_int80_start, NOTE_MASK);
359 *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
360 mask = VDSO32_SYMBOL(&vdso32_sysenter_start, NOTE_MASK);
361 *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
362#endif
363}
364
365static int __cpuinit register_callback(unsigned type, const void *func)
366{
367 struct callback_register callback = {
368 .type = type,
369 .address = XEN_CALLBACK(__KERNEL_CS, func),
370 .flags = CALLBACKF_mask_events,
371 };
372
373 return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
374}
375
376void __cpuinit xen_enable_sysenter(void)
377{
378 int ret;
379 unsigned sysenter_feature;
380
381#ifdef CONFIG_X86_32
382 sysenter_feature = X86_FEATURE_SEP;
383#else
384 sysenter_feature = X86_FEATURE_SYSENTER32;
385#endif
386
387 if (!boot_cpu_has(sysenter_feature))
388 return;
389
390 ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
391 if(ret != 0)
392 setup_clear_cpu_cap(sysenter_feature);
393}
394
395void __cpuinit xen_enable_syscall(void)
396{
397#ifdef CONFIG_X86_64
398 int ret;
399
400 ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
401 if (ret != 0) {
402 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
403 /* Pretty fatal; 64-bit userspace has no other
404 mechanism for syscalls. */
405 }
406
407 if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
408 ret = register_callback(CALLBACKTYPE_syscall32,
409 xen_syscall32_target);
410 if (ret != 0)
411 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
412 }
413#endif /* CONFIG_X86_64 */
414}
415
416void __init xen_arch_setup(void)
417{
418 xen_panic_handler_init();
419
420 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
421 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
422
423 if (!xen_feature(XENFEAT_auto_translated_physmap))
424 HYPERVISOR_vm_assist(VMASST_CMD_enable,
425 VMASST_TYPE_pae_extended_cr3);
426
427 if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
428 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
429 BUG();
430
431 xen_enable_sysenter();
432 xen_enable_syscall();
433
434#ifdef CONFIG_ACPI
435 if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
436 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
437 disable_acpi();
438 }
439#endif
440
441 memcpy(boot_command_line, xen_start_info->cmd_line,
442 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
443 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
444
445 /* Set up idle, making sure it calls safe_halt() pvop */
446#ifdef CONFIG_X86_32
447 boot_cpu_data.hlt_works_ok = 1;
448#endif
449 disable_cpuidle();
450 boot_option_idle_override = IDLE_HALT;
451
452 fiddle_vdso();
453}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Machine specific setup for xen
4 *
5 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
6 */
7
8#include <linux/init.h>
9#include <linux/sched.h>
10#include <linux/mm.h>
11#include <linux/pm.h>
12#include <linux/memblock.h>
13#include <linux/cpuidle.h>
14#include <linux/cpufreq.h>
15#include <linux/memory_hotplug.h>
16
17#include <asm/elf.h>
18#include <asm/vdso.h>
19#include <asm/e820/api.h>
20#include <asm/setup.h>
21#include <asm/acpi.h>
22#include <asm/numa.h>
23#include <asm/xen/hypervisor.h>
24#include <asm/xen/hypercall.h>
25
26#include <xen/xen.h>
27#include <xen/page.h>
28#include <xen/interface/callback.h>
29#include <xen/interface/memory.h>
30#include <xen/interface/physdev.h>
31#include <xen/features.h>
32#include <xen/hvc-console.h>
33#include "xen-ops.h"
34#include "vdso.h"
35#include "mmu.h"
36
37#define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024)
38
39/* Amount of extra memory space we add to the e820 ranges */
40struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
41
42/* Number of pages released from the initial allocation. */
43unsigned long xen_released_pages;
44
45/* E820 map used during setting up memory. */
46static struct e820_table xen_e820_table __initdata;
47
48/*
49 * Buffer used to remap identity mapped pages. We only need the virtual space.
50 * The physical page behind this address is remapped as needed to different
51 * buffer pages.
52 */
53#define REMAP_SIZE (P2M_PER_PAGE - 3)
54static struct {
55 unsigned long next_area_mfn;
56 unsigned long target_pfn;
57 unsigned long size;
58 unsigned long mfns[REMAP_SIZE];
59} xen_remap_buf __initdata __aligned(PAGE_SIZE);
60static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY;
61
62/*
63 * The maximum amount of extra memory compared to the base size. The
64 * main scaling factor is the size of struct page. At extreme ratios
65 * of base:extra, all the base memory can be filled with page
66 * structures for the extra memory, leaving no space for anything
67 * else.
68 *
69 * 10x seems like a reasonable balance between scaling flexibility and
70 * leaving a practically usable system.
71 */
72#define EXTRA_MEM_RATIO (10)
73
74static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB);
75
76static void __init xen_parse_512gb(void)
77{
78 bool val = false;
79 char *arg;
80
81 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit");
82 if (!arg)
83 return;
84
85 arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit=");
86 if (!arg)
87 val = true;
88 else if (strtobool(arg + strlen("xen_512gb_limit="), &val))
89 return;
90
91 xen_512gb_limit = val;
92}
93
94static void __init xen_add_extra_mem(unsigned long start_pfn,
95 unsigned long n_pfns)
96{
97 int i;
98
99 /*
100 * No need to check for zero size, should happen rarely and will only
101 * write a new entry regarded to be unused due to zero size.
102 */
103 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
104 /* Add new region. */
105 if (xen_extra_mem[i].n_pfns == 0) {
106 xen_extra_mem[i].start_pfn = start_pfn;
107 xen_extra_mem[i].n_pfns = n_pfns;
108 break;
109 }
110 /* Append to existing region. */
111 if (xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns ==
112 start_pfn) {
113 xen_extra_mem[i].n_pfns += n_pfns;
114 break;
115 }
116 }
117 if (i == XEN_EXTRA_MEM_MAX_REGIONS)
118 printk(KERN_WARNING "Warning: not enough extra memory regions\n");
119
120 memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
121}
122
123static void __init xen_del_extra_mem(unsigned long start_pfn,
124 unsigned long n_pfns)
125{
126 int i;
127 unsigned long start_r, size_r;
128
129 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
130 start_r = xen_extra_mem[i].start_pfn;
131 size_r = xen_extra_mem[i].n_pfns;
132
133 /* Start of region. */
134 if (start_r == start_pfn) {
135 BUG_ON(n_pfns > size_r);
136 xen_extra_mem[i].start_pfn += n_pfns;
137 xen_extra_mem[i].n_pfns -= n_pfns;
138 break;
139 }
140 /* End of region. */
141 if (start_r + size_r == start_pfn + n_pfns) {
142 BUG_ON(n_pfns > size_r);
143 xen_extra_mem[i].n_pfns -= n_pfns;
144 break;
145 }
146 /* Mid of region. */
147 if (start_pfn > start_r && start_pfn < start_r + size_r) {
148 BUG_ON(start_pfn + n_pfns > start_r + size_r);
149 xen_extra_mem[i].n_pfns = start_pfn - start_r;
150 /* Calling memblock_reserve() again is okay. */
151 xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r -
152 (start_pfn + n_pfns));
153 break;
154 }
155 }
156 memblock_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns));
157}
158
159/*
160 * Called during boot before the p2m list can take entries beyond the
161 * hypervisor supplied p2m list. Entries in extra mem are to be regarded as
162 * invalid.
163 */
164unsigned long __ref xen_chk_extra_mem(unsigned long pfn)
165{
166 int i;
167
168 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
169 if (pfn >= xen_extra_mem[i].start_pfn &&
170 pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns)
171 return INVALID_P2M_ENTRY;
172 }
173
174 return IDENTITY_FRAME(pfn);
175}
176
177/*
178 * Mark all pfns of extra mem as invalid in p2m list.
179 */
180void __init xen_inv_extra_mem(void)
181{
182 unsigned long pfn, pfn_s, pfn_e;
183 int i;
184
185 for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
186 if (!xen_extra_mem[i].n_pfns)
187 continue;
188 pfn_s = xen_extra_mem[i].start_pfn;
189 pfn_e = pfn_s + xen_extra_mem[i].n_pfns;
190 for (pfn = pfn_s; pfn < pfn_e; pfn++)
191 set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
192 }
193}
194
195/*
196 * Finds the next RAM pfn available in the E820 map after min_pfn.
197 * This function updates min_pfn with the pfn found and returns
198 * the size of that range or zero if not found.
199 */
200static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn)
201{
202 const struct e820_entry *entry = xen_e820_table.entries;
203 unsigned int i;
204 unsigned long done = 0;
205
206 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
207 unsigned long s_pfn;
208 unsigned long e_pfn;
209
210 if (entry->type != E820_TYPE_RAM)
211 continue;
212
213 e_pfn = PFN_DOWN(entry->addr + entry->size);
214
215 /* We only care about E820 after this */
216 if (e_pfn <= *min_pfn)
217 continue;
218
219 s_pfn = PFN_UP(entry->addr);
220
221 /* If min_pfn falls within the E820 entry, we want to start
222 * at the min_pfn PFN.
223 */
224 if (s_pfn <= *min_pfn) {
225 done = e_pfn - *min_pfn;
226 } else {
227 done = e_pfn - s_pfn;
228 *min_pfn = s_pfn;
229 }
230 break;
231 }
232
233 return done;
234}
235
236static int __init xen_free_mfn(unsigned long mfn)
237{
238 struct xen_memory_reservation reservation = {
239 .address_bits = 0,
240 .extent_order = 0,
241 .domid = DOMID_SELF
242 };
243
244 set_xen_guest_handle(reservation.extent_start, &mfn);
245 reservation.nr_extents = 1;
246
247 return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
248}
249
250/*
251 * This releases a chunk of memory and then does the identity map. It's used
252 * as a fallback if the remapping fails.
253 */
254static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn,
255 unsigned long end_pfn, unsigned long nr_pages)
256{
257 unsigned long pfn, end;
258 int ret;
259
260 WARN_ON(start_pfn > end_pfn);
261
262 /* Release pages first. */
263 end = min(end_pfn, nr_pages);
264 for (pfn = start_pfn; pfn < end; pfn++) {
265 unsigned long mfn = pfn_to_mfn(pfn);
266
267 /* Make sure pfn exists to start with */
268 if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
269 continue;
270
271 ret = xen_free_mfn(mfn);
272 WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret);
273
274 if (ret == 1) {
275 xen_released_pages++;
276 if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY))
277 break;
278 } else
279 break;
280 }
281
282 set_phys_range_identity(start_pfn, end_pfn);
283}
284
285/*
286 * Helper function to update the p2m and m2p tables and kernel mapping.
287 */
288static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn)
289{
290 struct mmu_update update = {
291 .ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE,
292 .val = pfn
293 };
294
295 /* Update p2m */
296 if (!set_phys_to_machine(pfn, mfn)) {
297 WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n",
298 pfn, mfn);
299 BUG();
300 }
301
302 /* Update m2p */
303 if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) {
304 WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n",
305 mfn, pfn);
306 BUG();
307 }
308
309 /* Update kernel mapping, but not for highmem. */
310 if (pfn >= PFN_UP(__pa(high_memory - 1)))
311 return;
312
313 if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT),
314 mfn_pte(mfn, PAGE_KERNEL), 0)) {
315 WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n",
316 mfn, pfn);
317 BUG();
318 }
319}
320
321/*
322 * This function updates the p2m and m2p tables with an identity map from
323 * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the
324 * original allocation at remap_pfn. The information needed for remapping is
325 * saved in the memory itself to avoid the need for allocating buffers. The
326 * complete remap information is contained in a list of MFNs each containing
327 * up to REMAP_SIZE MFNs and the start target PFN for doing the remap.
328 * This enables us to preserve the original mfn sequence while doing the
329 * remapping at a time when the memory management is capable of allocating
330 * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and
331 * its callers.
332 */
333static void __init xen_do_set_identity_and_remap_chunk(
334 unsigned long start_pfn, unsigned long size, unsigned long remap_pfn)
335{
336 unsigned long buf = (unsigned long)&xen_remap_buf;
337 unsigned long mfn_save, mfn;
338 unsigned long ident_pfn_iter, remap_pfn_iter;
339 unsigned long ident_end_pfn = start_pfn + size;
340 unsigned long left = size;
341 unsigned int i, chunk;
342
343 WARN_ON(size == 0);
344
345 mfn_save = virt_to_mfn(buf);
346
347 for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn;
348 ident_pfn_iter < ident_end_pfn;
349 ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) {
350 chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE;
351
352 /* Map first pfn to xen_remap_buf */
353 mfn = pfn_to_mfn(ident_pfn_iter);
354 set_pte_mfn(buf, mfn, PAGE_KERNEL);
355
356 /* Save mapping information in page */
357 xen_remap_buf.next_area_mfn = xen_remap_mfn;
358 xen_remap_buf.target_pfn = remap_pfn_iter;
359 xen_remap_buf.size = chunk;
360 for (i = 0; i < chunk; i++)
361 xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i);
362
363 /* Put remap buf into list. */
364 xen_remap_mfn = mfn;
365
366 /* Set identity map */
367 set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk);
368
369 left -= chunk;
370 }
371
372 /* Restore old xen_remap_buf mapping */
373 set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
374}
375
376/*
377 * This function takes a contiguous pfn range that needs to be identity mapped
378 * and:
379 *
380 * 1) Finds a new range of pfns to use to remap based on E820 and remap_pfn.
381 * 2) Calls the do_ function to actually do the mapping/remapping work.
382 *
383 * The goal is to not allocate additional memory but to remap the existing
384 * pages. In the case of an error the underlying memory is simply released back
385 * to Xen and not remapped.
386 */
387static unsigned long __init xen_set_identity_and_remap_chunk(
388 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
389 unsigned long remap_pfn)
390{
391 unsigned long pfn;
392 unsigned long i = 0;
393 unsigned long n = end_pfn - start_pfn;
394
395 if (remap_pfn == 0)
396 remap_pfn = nr_pages;
397
398 while (i < n) {
399 unsigned long cur_pfn = start_pfn + i;
400 unsigned long left = n - i;
401 unsigned long size = left;
402 unsigned long remap_range_size;
403
404 /* Do not remap pages beyond the current allocation */
405 if (cur_pfn >= nr_pages) {
406 /* Identity map remaining pages */
407 set_phys_range_identity(cur_pfn, cur_pfn + size);
408 break;
409 }
410 if (cur_pfn + size > nr_pages)
411 size = nr_pages - cur_pfn;
412
413 remap_range_size = xen_find_pfn_range(&remap_pfn);
414 if (!remap_range_size) {
415 pr_warning("Unable to find available pfn range, not remapping identity pages\n");
416 xen_set_identity_and_release_chunk(cur_pfn,
417 cur_pfn + left, nr_pages);
418 break;
419 }
420 /* Adjust size to fit in current e820 RAM region */
421 if (size > remap_range_size)
422 size = remap_range_size;
423
424 xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn);
425
426 /* Update variables to reflect new mappings. */
427 i += size;
428 remap_pfn += size;
429 }
430
431 /*
432 * If the PFNs are currently mapped, the VA mapping also needs
433 * to be updated to be 1:1.
434 */
435 for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++)
436 (void)HYPERVISOR_update_va_mapping(
437 (unsigned long)__va(pfn << PAGE_SHIFT),
438 mfn_pte(pfn, PAGE_KERNEL_IO), 0);
439
440 return remap_pfn;
441}
442
443static unsigned long __init xen_count_remap_pages(
444 unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
445 unsigned long remap_pages)
446{
447 if (start_pfn >= nr_pages)
448 return remap_pages;
449
450 return remap_pages + min(end_pfn, nr_pages) - start_pfn;
451}
452
453static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages,
454 unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn,
455 unsigned long nr_pages, unsigned long last_val))
456{
457 phys_addr_t start = 0;
458 unsigned long ret_val = 0;
459 const struct e820_entry *entry = xen_e820_table.entries;
460 int i;
461
462 /*
463 * Combine non-RAM regions and gaps until a RAM region (or the
464 * end of the map) is reached, then call the provided function
465 * to perform its duty on the non-RAM region.
466 *
467 * The combined non-RAM regions are rounded to a whole number
468 * of pages so any partial pages are accessible via the 1:1
469 * mapping. This is needed for some BIOSes that put (for
470 * example) the DMI tables in a reserved region that begins on
471 * a non-page boundary.
472 */
473 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
474 phys_addr_t end = entry->addr + entry->size;
475 if (entry->type == E820_TYPE_RAM || i == xen_e820_table.nr_entries - 1) {
476 unsigned long start_pfn = PFN_DOWN(start);
477 unsigned long end_pfn = PFN_UP(end);
478
479 if (entry->type == E820_TYPE_RAM)
480 end_pfn = PFN_UP(entry->addr);
481
482 if (start_pfn < end_pfn)
483 ret_val = func(start_pfn, end_pfn, nr_pages,
484 ret_val);
485 start = end;
486 }
487 }
488
489 return ret_val;
490}
491
492/*
493 * Remap the memory prepared in xen_do_set_identity_and_remap_chunk().
494 * The remap information (which mfn remap to which pfn) is contained in the
495 * to be remapped memory itself in a linked list anchored at xen_remap_mfn.
496 * This scheme allows to remap the different chunks in arbitrary order while
497 * the resulting mapping will be independent from the order.
498 */
499void __init xen_remap_memory(void)
500{
501 unsigned long buf = (unsigned long)&xen_remap_buf;
502 unsigned long mfn_save, pfn;
503 unsigned long remapped = 0;
504 unsigned int i;
505 unsigned long pfn_s = ~0UL;
506 unsigned long len = 0;
507
508 mfn_save = virt_to_mfn(buf);
509
510 while (xen_remap_mfn != INVALID_P2M_ENTRY) {
511 /* Map the remap information */
512 set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL);
513
514 BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]);
515
516 pfn = xen_remap_buf.target_pfn;
517 for (i = 0; i < xen_remap_buf.size; i++) {
518 xen_update_mem_tables(pfn, xen_remap_buf.mfns[i]);
519 remapped++;
520 pfn++;
521 }
522 if (pfn_s == ~0UL || pfn == pfn_s) {
523 pfn_s = xen_remap_buf.target_pfn;
524 len += xen_remap_buf.size;
525 } else if (pfn_s + len == xen_remap_buf.target_pfn) {
526 len += xen_remap_buf.size;
527 } else {
528 xen_del_extra_mem(pfn_s, len);
529 pfn_s = xen_remap_buf.target_pfn;
530 len = xen_remap_buf.size;
531 }
532 xen_remap_mfn = xen_remap_buf.next_area_mfn;
533 }
534
535 if (pfn_s != ~0UL && len)
536 xen_del_extra_mem(pfn_s, len);
537
538 set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
539
540 pr_info("Remapped %ld page(s)\n", remapped);
541}
542
543static unsigned long __init xen_get_pages_limit(void)
544{
545 unsigned long limit;
546
547#ifdef CONFIG_X86_32
548 limit = GB(64) / PAGE_SIZE;
549#else
550 limit = MAXMEM / PAGE_SIZE;
551 if (!xen_initial_domain() && xen_512gb_limit)
552 limit = GB(512) / PAGE_SIZE;
553#endif
554 return limit;
555}
556
557static unsigned long __init xen_get_max_pages(void)
558{
559 unsigned long max_pages, limit;
560 domid_t domid = DOMID_SELF;
561 long ret;
562
563 limit = xen_get_pages_limit();
564 max_pages = limit;
565
566 /*
567 * For the initial domain we use the maximum reservation as
568 * the maximum page.
569 *
570 * For guest domains the current maximum reservation reflects
571 * the current maximum rather than the static maximum. In this
572 * case the e820 map provided to us will cover the static
573 * maximum region.
574 */
575 if (xen_initial_domain()) {
576 ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
577 if (ret > 0)
578 max_pages = ret;
579 }
580
581 return min(max_pages, limit);
582}
583
584static void __init xen_align_and_add_e820_region(phys_addr_t start,
585 phys_addr_t size, int type)
586{
587 phys_addr_t end = start + size;
588
589 /* Align RAM regions to page boundaries. */
590 if (type == E820_TYPE_RAM) {
591 start = PAGE_ALIGN(start);
592 end &= ~((phys_addr_t)PAGE_SIZE - 1);
593#ifdef CONFIG_MEMORY_HOTPLUG
594 /*
595 * Don't allow adding memory not in E820 map while booting the
596 * system. Once the balloon driver is up it will remove that
597 * restriction again.
598 */
599 max_mem_size = end;
600#endif
601 }
602
603 e820__range_add(start, end - start, type);
604}
605
606static void __init xen_ignore_unusable(void)
607{
608 struct e820_entry *entry = xen_e820_table.entries;
609 unsigned int i;
610
611 for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) {
612 if (entry->type == E820_TYPE_UNUSABLE)
613 entry->type = E820_TYPE_RAM;
614 }
615}
616
617bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size)
618{
619 struct e820_entry *entry;
620 unsigned mapcnt;
621 phys_addr_t end;
622
623 if (!size)
624 return false;
625
626 end = start + size;
627 entry = xen_e820_table.entries;
628
629 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) {
630 if (entry->type == E820_TYPE_RAM && entry->addr <= start &&
631 (entry->addr + entry->size) >= end)
632 return false;
633
634 entry++;
635 }
636
637 return true;
638}
639
640/*
641 * Find a free area in physical memory not yet reserved and compliant with
642 * E820 map.
643 * Used to relocate pre-allocated areas like initrd or p2m list which are in
644 * conflict with the to be used E820 map.
645 * In case no area is found, return 0. Otherwise return the physical address
646 * of the area which is already reserved for convenience.
647 */
648phys_addr_t __init xen_find_free_area(phys_addr_t size)
649{
650 unsigned mapcnt;
651 phys_addr_t addr, start;
652 struct e820_entry *entry = xen_e820_table.entries;
653
654 for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++, entry++) {
655 if (entry->type != E820_TYPE_RAM || entry->size < size)
656 continue;
657 start = entry->addr;
658 for (addr = start; addr < start + size; addr += PAGE_SIZE) {
659 if (!memblock_is_reserved(addr))
660 continue;
661 start = addr + PAGE_SIZE;
662 if (start + size > entry->addr + entry->size)
663 break;
664 }
665 if (addr >= start + size) {
666 memblock_reserve(start, size);
667 return start;
668 }
669 }
670
671 return 0;
672}
673
674/*
675 * Like memcpy, but with physical addresses for dest and src.
676 */
677static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src,
678 phys_addr_t n)
679{
680 phys_addr_t dest_off, src_off, dest_len, src_len, len;
681 void *from, *to;
682
683 while (n) {
684 dest_off = dest & ~PAGE_MASK;
685 src_off = src & ~PAGE_MASK;
686 dest_len = n;
687 if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off)
688 dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off;
689 src_len = n;
690 if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off)
691 src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off;
692 len = min(dest_len, src_len);
693 to = early_memremap(dest - dest_off, dest_len + dest_off);
694 from = early_memremap(src - src_off, src_len + src_off);
695 memcpy(to, from, len);
696 early_memunmap(to, dest_len + dest_off);
697 early_memunmap(from, src_len + src_off);
698 n -= len;
699 dest += len;
700 src += len;
701 }
702}
703
704/*
705 * Reserve Xen mfn_list.
706 */
707static void __init xen_reserve_xen_mfnlist(void)
708{
709 phys_addr_t start, size;
710
711 if (xen_start_info->mfn_list >= __START_KERNEL_map) {
712 start = __pa(xen_start_info->mfn_list);
713 size = PFN_ALIGN(xen_start_info->nr_pages *
714 sizeof(unsigned long));
715 } else {
716 start = PFN_PHYS(xen_start_info->first_p2m_pfn);
717 size = PFN_PHYS(xen_start_info->nr_p2m_frames);
718 }
719
720 memblock_reserve(start, size);
721 if (!xen_is_e820_reserved(start, size))
722 return;
723
724#ifdef CONFIG_X86_32
725 /*
726 * Relocating the p2m on 32 bit system to an arbitrary virtual address
727 * is not supported, so just give up.
728 */
729 xen_raw_console_write("Xen hypervisor allocated p2m list conflicts with E820 map\n");
730 BUG();
731#else
732 xen_relocate_p2m();
733 memblock_free(start, size);
734#endif
735}
736
737/**
738 * machine_specific_memory_setup - Hook for machine specific memory setup.
739 **/
740char * __init xen_memory_setup(void)
741{
742 unsigned long max_pfn, pfn_s, n_pfns;
743 phys_addr_t mem_end, addr, size, chunk_size;
744 u32 type;
745 int rc;
746 struct xen_memory_map memmap;
747 unsigned long max_pages;
748 unsigned long extra_pages = 0;
749 int i;
750 int op;
751
752 xen_parse_512gb();
753 max_pfn = xen_get_pages_limit();
754 max_pfn = min(max_pfn, xen_start_info->nr_pages);
755 mem_end = PFN_PHYS(max_pfn);
756
757 memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries);
758 set_xen_guest_handle(memmap.buffer, xen_e820_table.entries);
759
760#if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON)
761 xen_saved_max_mem_size = max_mem_size;
762#endif
763
764 op = xen_initial_domain() ?
765 XENMEM_machine_memory_map :
766 XENMEM_memory_map;
767 rc = HYPERVISOR_memory_op(op, &memmap);
768 if (rc == -ENOSYS) {
769 BUG_ON(xen_initial_domain());
770 memmap.nr_entries = 1;
771 xen_e820_table.entries[0].addr = 0ULL;
772 xen_e820_table.entries[0].size = mem_end;
773 /* 8MB slack (to balance backend allocations). */
774 xen_e820_table.entries[0].size += 8ULL << 20;
775 xen_e820_table.entries[0].type = E820_TYPE_RAM;
776 rc = 0;
777 }
778 BUG_ON(rc);
779 BUG_ON(memmap.nr_entries == 0);
780 xen_e820_table.nr_entries = memmap.nr_entries;
781
782 /*
783 * Xen won't allow a 1:1 mapping to be created to UNUSABLE
784 * regions, so if we're using the machine memory map leave the
785 * region as RAM as it is in the pseudo-physical map.
786 *
787 * UNUSABLE regions in domUs are not handled and will need
788 * a patch in the future.
789 */
790 if (xen_initial_domain())
791 xen_ignore_unusable();
792
793 /* Make sure the Xen-supplied memory map is well-ordered. */
794 e820__update_table(&xen_e820_table);
795
796 max_pages = xen_get_max_pages();
797
798 /* How many extra pages do we need due to remapping? */
799 max_pages += xen_foreach_remap_area(max_pfn, xen_count_remap_pages);
800
801 if (max_pages > max_pfn)
802 extra_pages += max_pages - max_pfn;
803
804 /*
805 * Clamp the amount of extra memory to a EXTRA_MEM_RATIO
806 * factor the base size. On non-highmem systems, the base
807 * size is the full initial memory allocation; on highmem it
808 * is limited to the max size of lowmem, so that it doesn't
809 * get completely filled.
810 *
811 * Make sure we have no memory above max_pages, as this area
812 * isn't handled by the p2m management.
813 *
814 * In principle there could be a problem in lowmem systems if
815 * the initial memory is also very large with respect to
816 * lowmem, but we won't try to deal with that here.
817 */
818 extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)),
819 extra_pages, max_pages - max_pfn);
820 i = 0;
821 addr = xen_e820_table.entries[0].addr;
822 size = xen_e820_table.entries[0].size;
823 while (i < xen_e820_table.nr_entries) {
824 bool discard = false;
825
826 chunk_size = size;
827 type = xen_e820_table.entries[i].type;
828
829 if (type == E820_TYPE_RAM) {
830 if (addr < mem_end) {
831 chunk_size = min(size, mem_end - addr);
832 } else if (extra_pages) {
833 chunk_size = min(size, PFN_PHYS(extra_pages));
834 pfn_s = PFN_UP(addr);
835 n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s;
836 extra_pages -= n_pfns;
837 xen_add_extra_mem(pfn_s, n_pfns);
838 xen_max_p2m_pfn = pfn_s + n_pfns;
839 } else
840 discard = true;
841 }
842
843 if (!discard)
844 xen_align_and_add_e820_region(addr, chunk_size, type);
845
846 addr += chunk_size;
847 size -= chunk_size;
848 if (size == 0) {
849 i++;
850 if (i < xen_e820_table.nr_entries) {
851 addr = xen_e820_table.entries[i].addr;
852 size = xen_e820_table.entries[i].size;
853 }
854 }
855 }
856
857 /*
858 * Set the rest as identity mapped, in case PCI BARs are
859 * located here.
860 */
861 set_phys_range_identity(addr / PAGE_SIZE, ~0ul);
862
863 /*
864 * In domU, the ISA region is normal, usable memory, but we
865 * reserve ISA memory anyway because too many things poke
866 * about in there.
867 */
868 e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_TYPE_RESERVED);
869
870 e820__update_table(e820_table);
871
872 /*
873 * Check whether the kernel itself conflicts with the target E820 map.
874 * Failing now is better than running into weird problems later due
875 * to relocating (and even reusing) pages with kernel text or data.
876 */
877 if (xen_is_e820_reserved(__pa_symbol(_text),
878 __pa_symbol(__bss_stop) - __pa_symbol(_text))) {
879 xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n");
880 BUG();
881 }
882
883 /*
884 * Check for a conflict of the hypervisor supplied page tables with
885 * the target E820 map.
886 */
887 xen_pt_check_e820();
888
889 xen_reserve_xen_mfnlist();
890
891 /* Check for a conflict of the initrd with the target E820 map. */
892 if (xen_is_e820_reserved(boot_params.hdr.ramdisk_image,
893 boot_params.hdr.ramdisk_size)) {
894 phys_addr_t new_area, start, size;
895
896 new_area = xen_find_free_area(boot_params.hdr.ramdisk_size);
897 if (!new_area) {
898 xen_raw_console_write("Can't find new memory area for initrd needed due to E820 map conflict\n");
899 BUG();
900 }
901
902 start = boot_params.hdr.ramdisk_image;
903 size = boot_params.hdr.ramdisk_size;
904 xen_phys_memcpy(new_area, start, size);
905 pr_info("initrd moved from [mem %#010llx-%#010llx] to [mem %#010llx-%#010llx]\n",
906 start, start + size, new_area, new_area + size);
907 memblock_free(start, size);
908 boot_params.hdr.ramdisk_image = new_area;
909 boot_params.ext_ramdisk_image = new_area >> 32;
910 }
911
912 /*
913 * Set identity map on non-RAM pages and prepare remapping the
914 * underlying RAM.
915 */
916 xen_foreach_remap_area(max_pfn, xen_set_identity_and_remap_chunk);
917
918 pr_info("Released %ld page(s)\n", xen_released_pages);
919
920 return "Xen";
921}
922
923/*
924 * Set the bit indicating "nosegneg" library variants should be used.
925 * We only need to bother in pure 32-bit mode; compat 32-bit processes
926 * can have un-truncated segments, so wrapping around is allowed.
927 */
928static void __init fiddle_vdso(void)
929{
930#ifdef CONFIG_X86_32
931 u32 *mask = vdso_image_32.data +
932 vdso_image_32.sym_VDSO32_NOTE_MASK;
933 *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
934#endif
935}
936
937static int register_callback(unsigned type, const void *func)
938{
939 struct callback_register callback = {
940 .type = type,
941 .address = XEN_CALLBACK(__KERNEL_CS, func),
942 .flags = CALLBACKF_mask_events,
943 };
944
945 return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
946}
947
948void xen_enable_sysenter(void)
949{
950 int ret;
951 unsigned sysenter_feature;
952
953#ifdef CONFIG_X86_32
954 sysenter_feature = X86_FEATURE_SEP;
955#else
956 sysenter_feature = X86_FEATURE_SYSENTER32;
957#endif
958
959 if (!boot_cpu_has(sysenter_feature))
960 return;
961
962 ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
963 if(ret != 0)
964 setup_clear_cpu_cap(sysenter_feature);
965}
966
967void xen_enable_syscall(void)
968{
969#ifdef CONFIG_X86_64
970 int ret;
971
972 ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
973 if (ret != 0) {
974 printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
975 /* Pretty fatal; 64-bit userspace has no other
976 mechanism for syscalls. */
977 }
978
979 if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
980 ret = register_callback(CALLBACKTYPE_syscall32,
981 xen_syscall32_target);
982 if (ret != 0)
983 setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
984 }
985#endif /* CONFIG_X86_64 */
986}
987
988void __init xen_pvmmu_arch_setup(void)
989{
990 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
991 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
992
993 HYPERVISOR_vm_assist(VMASST_CMD_enable,
994 VMASST_TYPE_pae_extended_cr3);
995
996 if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
997 register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
998 BUG();
999
1000 xen_enable_sysenter();
1001 xen_enable_syscall();
1002}
1003
1004/* This function is not called for HVM domains */
1005void __init xen_arch_setup(void)
1006{
1007 xen_panic_handler_init();
1008 xen_pvmmu_arch_setup();
1009
1010#ifdef CONFIG_ACPI
1011 if (!(xen_start_info->flags & SIF_INITDOMAIN)) {
1012 printk(KERN_INFO "ACPI in unprivileged domain disabled\n");
1013 disable_acpi();
1014 }
1015#endif
1016
1017 memcpy(boot_command_line, xen_start_info->cmd_line,
1018 MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
1019 COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
1020
1021 /* Set up idle, making sure it calls safe_halt() pvop */
1022 disable_cpuidle();
1023 disable_cpufreq();
1024 WARN_ON(xen_set_default_idle());
1025 fiddle_vdso();
1026#ifdef CONFIG_NUMA
1027 numa_off = 1;
1028#endif
1029}