974a528458a04d3257234ceb70991b7f01eb3748
[pandora-kernel.git] / arch / x86 / xen / enlighten.c
1 /*
2  * Core of Xen paravirt_ops implementation.
3  *
4  * This file contains the xen_paravirt_ops structure itself, and the
5  * implementations for:
6  * - privileged instructions
7  * - interrupt flags
8  * - segment operations
9  * - booting and setup
10  *
11  * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
12  */
13
14 #include <linux/cpu.h>
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/smp.h>
18 #include <linux/preempt.h>
19 #include <linux/hardirq.h>
20 #include <linux/percpu.h>
21 #include <linux/delay.h>
22 #include <linux/start_kernel.h>
23 #include <linux/sched.h>
24 #include <linux/kprobes.h>
25 #include <linux/bootmem.h>
26 #include <linux/module.h>
27 #include <linux/mm.h>
28 #include <linux/page-flags.h>
29 #include <linux/highmem.h>
30 #include <linux/console.h>
31 #include <linux/pci.h>
32 #include <linux/gfp.h>
33 #include <linux/memblock.h>
34
35 #include <xen/xen.h>
36 #include <xen/interface/xen.h>
37 #include <xen/interface/version.h>
38 #include <xen/interface/physdev.h>
39 #include <xen/interface/vcpu.h>
40 #include <xen/interface/memory.h>
41 #include <xen/features.h>
42 #include <xen/page.h>
43 #include <xen/hvm.h>
44 #include <xen/hvc-console.h>
45
46 #include <asm/paravirt.h>
47 #include <asm/apic.h>
48 #include <asm/page.h>
49 #include <asm/xen/pci.h>
50 #include <asm/xen/hypercall.h>
51 #include <asm/xen/hypervisor.h>
52 #include <asm/fixmap.h>
53 #include <asm/processor.h>
54 #include <asm/proto.h>
55 #include <asm/msr-index.h>
56 #include <asm/traps.h>
57 #include <asm/setup.h>
58 #include <asm/desc.h>
59 #include <asm/pgalloc.h>
60 #include <asm/pgtable.h>
61 #include <asm/tlbflush.h>
62 #include <asm/reboot.h>
63 #include <asm/stackprotector.h>
64 #include <asm/hypervisor.h>
65
66 #include "xen-ops.h"
67 #include "mmu.h"
68 #include "multicalls.h"
69
70 EXPORT_SYMBOL_GPL(hypercall_page);
71
72 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
73 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
74
75 enum xen_domain_type xen_domain_type = XEN_NATIVE;
76 EXPORT_SYMBOL_GPL(xen_domain_type);
77
78 unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START;
79 EXPORT_SYMBOL(machine_to_phys_mapping);
80 unsigned int   machine_to_phys_order;
81 EXPORT_SYMBOL(machine_to_phys_order);
82
83 struct start_info *xen_start_info;
84 EXPORT_SYMBOL_GPL(xen_start_info);
85
86 struct shared_info xen_dummy_shared_info;
87
88 void *xen_initial_gdt;
89
90 RESERVE_BRK(shared_info_page_brk, PAGE_SIZE);
91 __read_mostly int xen_have_vector_callback;
92 EXPORT_SYMBOL_GPL(xen_have_vector_callback);
93
94 /*
95  * Point at some empty memory to start with. We map the real shared_info
96  * page as soon as fixmap is up and running.
97  */
98 struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
99
100 /*
101  * Flag to determine whether vcpu info placement is available on all
102  * VCPUs.  We assume it is to start with, and then set it to zero on
103  * the first failure.  This is because it can succeed on some VCPUs
104  * and not others, since it can involve hypervisor memory allocation,
105  * or because the guest failed to guarantee all the appropriate
106  * constraints on all VCPUs (ie buffer can't cross a page boundary).
107  *
108  * Note that any particular CPU may be using a placed vcpu structure,
109  * but we can only optimise if the all are.
110  *
111  * 0: not available, 1: available
112  */
113 static int have_vcpu_info_placement = 1;
114
115 static void clamp_max_cpus(void)
116 {
117 #ifdef CONFIG_SMP
118         if (setup_max_cpus > MAX_VIRT_CPUS)
119                 setup_max_cpus = MAX_VIRT_CPUS;
120 #endif
121 }
122
123 static void xen_vcpu_setup(int cpu)
124 {
125         struct vcpu_register_vcpu_info info;
126         int err;
127         struct vcpu_info *vcpup;
128
129         BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
130
131         if (cpu < MAX_VIRT_CPUS)
132                 per_cpu(xen_vcpu,cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
133
134         if (!have_vcpu_info_placement) {
135                 if (cpu >= MAX_VIRT_CPUS)
136                         clamp_max_cpus();
137                 return;
138         }
139
140         vcpup = &per_cpu(xen_vcpu_info, cpu);
141         info.mfn = arbitrary_virt_to_mfn(vcpup);
142         info.offset = offset_in_page(vcpup);
143
144         /* Check to see if the hypervisor will put the vcpu_info
145            structure where we want it, which allows direct access via
146            a percpu-variable. */
147         err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
148
149         if (err) {
150                 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
151                 have_vcpu_info_placement = 0;
152                 clamp_max_cpus();
153         } else {
154                 /* This cpu is using the registered vcpu info, even if
155                    later ones fail to. */
156                 per_cpu(xen_vcpu, cpu) = vcpup;
157         }
158 }
159
160 /*
161  * On restore, set the vcpu placement up again.
162  * If it fails, then we're in a bad state, since
163  * we can't back out from using it...
164  */
165 void xen_vcpu_restore(void)
166 {
167         int cpu;
168
169         for_each_online_cpu(cpu) {
170                 bool other_cpu = (cpu != smp_processor_id());
171
172                 if (other_cpu &&
173                     HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL))
174                         BUG();
175
176                 xen_setup_runstate_info(cpu);
177
178                 if (have_vcpu_info_placement)
179                         xen_vcpu_setup(cpu);
180
181                 if (other_cpu &&
182                     HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
183                         BUG();
184         }
185 }
186
187 static void __init xen_banner(void)
188 {
189         unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
190         struct xen_extraversion extra;
191         HYPERVISOR_xen_version(XENVER_extraversion, &extra);
192
193         printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
194                pv_info.name);
195         printk(KERN_INFO "Xen version: %d.%d%s%s\n",
196                version >> 16, version & 0xffff, extra.extraversion,
197                xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
198 }
199
200 static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
201 static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
202
203 static void xen_cpuid(unsigned int *ax, unsigned int *bx,
204                       unsigned int *cx, unsigned int *dx)
205 {
206         unsigned maskebx = ~0;
207         unsigned maskecx = ~0;
208         unsigned maskedx = ~0;
209
210         /*
211          * Mask out inconvenient features, to try and disable as many
212          * unsupported kernel subsystems as possible.
213          */
214         switch (*ax) {
215         case 1:
216                 maskecx = cpuid_leaf1_ecx_mask;
217                 maskedx = cpuid_leaf1_edx_mask;
218                 break;
219
220         case 0xb:
221                 /* Suppress extended topology stuff */
222                 maskebx = 0;
223                 break;
224         }
225
226         asm(XEN_EMULATE_PREFIX "cpuid"
227                 : "=a" (*ax),
228                   "=b" (*bx),
229                   "=c" (*cx),
230                   "=d" (*dx)
231                 : "0" (*ax), "2" (*cx));
232
233         *bx &= maskebx;
234         *cx &= maskecx;
235         *dx &= maskedx;
236 }
237
238 static void __init xen_init_cpuid_mask(void)
239 {
240         unsigned int ax, bx, cx, dx;
241         unsigned int xsave_mask;
242
243         cpuid_leaf1_edx_mask =
244                 ~((1 << X86_FEATURE_MCE)  |  /* disable MCE */
245                   (1 << X86_FEATURE_MCA)  |  /* disable MCA */
246                   (1 << X86_FEATURE_MTRR) |  /* disable MTRR */
247                   (1 << X86_FEATURE_ACC));   /* thermal monitoring */
248
249         if (!xen_initial_domain())
250                 cpuid_leaf1_edx_mask &=
251                         ~((1 << X86_FEATURE_APIC) |  /* disable local APIC */
252                           (1 << X86_FEATURE_ACPI));  /* disable ACPI */
253         ax = 1;
254         xen_cpuid(&ax, &bx, &cx, &dx);
255
256         xsave_mask =
257                 (1 << (X86_FEATURE_XSAVE % 32)) |
258                 (1 << (X86_FEATURE_OSXSAVE % 32));
259
260         /* Xen will set CR4.OSXSAVE if supported and not disabled by force */
261         if ((cx & xsave_mask) != xsave_mask)
262                 cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */
263 }
264
265 static void xen_set_debugreg(int reg, unsigned long val)
266 {
267         HYPERVISOR_set_debugreg(reg, val);
268 }
269
270 static unsigned long xen_get_debugreg(int reg)
271 {
272         return HYPERVISOR_get_debugreg(reg);
273 }
274
275 static void xen_end_context_switch(struct task_struct *next)
276 {
277         xen_mc_flush();
278         paravirt_end_context_switch(next);
279 }
280
281 static unsigned long xen_store_tr(void)
282 {
283         return 0;
284 }
285
286 /*
287  * Set the page permissions for a particular virtual address.  If the
288  * address is a vmalloc mapping (or other non-linear mapping), then
289  * find the linear mapping of the page and also set its protections to
290  * match.
291  */
292 static void set_aliased_prot(void *v, pgprot_t prot)
293 {
294         int level;
295         pte_t *ptep;
296         pte_t pte;
297         unsigned long pfn;
298         struct page *page;
299
300         ptep = lookup_address((unsigned long)v, &level);
301         BUG_ON(ptep == NULL);
302
303         pfn = pte_pfn(*ptep);
304         page = pfn_to_page(pfn);
305
306         pte = pfn_pte(pfn, prot);
307
308         if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
309                 BUG();
310
311         if (!PageHighMem(page)) {
312                 void *av = __va(PFN_PHYS(pfn));
313
314                 if (av != v)
315                         if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
316                                 BUG();
317         } else
318                 kmap_flush_unused();
319 }
320
321 static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
322 {
323         const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
324         int i;
325
326         for(i = 0; i < entries; i += entries_per_page)
327                 set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
328 }
329
330 static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
331 {
332         const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
333         int i;
334
335         for(i = 0; i < entries; i += entries_per_page)
336                 set_aliased_prot(ldt + i, PAGE_KERNEL);
337 }
338
339 static void xen_set_ldt(const void *addr, unsigned entries)
340 {
341         struct mmuext_op *op;
342         struct multicall_space mcs = xen_mc_entry(sizeof(*op));
343
344         trace_xen_cpu_set_ldt(addr, entries);
345
346         op = mcs.args;
347         op->cmd = MMUEXT_SET_LDT;
348         op->arg1.linear_addr = (unsigned long)addr;
349         op->arg2.nr_ents = entries;
350
351         MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
352
353         xen_mc_issue(PARAVIRT_LAZY_CPU);
354 }
355
356 static void xen_load_gdt(const struct desc_ptr *dtr)
357 {
358         unsigned long va = dtr->address;
359         unsigned int size = dtr->size + 1;
360         unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
361         unsigned long frames[pages];
362         int f;
363
364         /*
365          * A GDT can be up to 64k in size, which corresponds to 8192
366          * 8-byte entries, or 16 4k pages..
367          */
368
369         BUG_ON(size > 65536);
370         BUG_ON(va & ~PAGE_MASK);
371
372         for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
373                 int level;
374                 pte_t *ptep;
375                 unsigned long pfn, mfn;
376                 void *virt;
377
378                 /*
379                  * The GDT is per-cpu and is in the percpu data area.
380                  * That can be virtually mapped, so we need to do a
381                  * page-walk to get the underlying MFN for the
382                  * hypercall.  The page can also be in the kernel's
383                  * linear range, so we need to RO that mapping too.
384                  */
385                 ptep = lookup_address(va, &level);
386                 BUG_ON(ptep == NULL);
387
388                 pfn = pte_pfn(*ptep);
389                 mfn = pfn_to_mfn(pfn);
390                 virt = __va(PFN_PHYS(pfn));
391
392                 frames[f] = mfn;
393
394                 make_lowmem_page_readonly((void *)va);
395                 make_lowmem_page_readonly(virt);
396         }
397
398         if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
399                 BUG();
400 }
401
402 /*
403  * load_gdt for early boot, when the gdt is only mapped once
404  */
405 static void __init xen_load_gdt_boot(const struct desc_ptr *dtr)
406 {
407         unsigned long va = dtr->address;
408         unsigned int size = dtr->size + 1;
409         unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
410         unsigned long frames[pages];
411         int f;
412
413         /*
414          * A GDT can be up to 64k in size, which corresponds to 8192
415          * 8-byte entries, or 16 4k pages..
416          */
417
418         BUG_ON(size > 65536);
419         BUG_ON(va & ~PAGE_MASK);
420
421         for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
422                 pte_t pte;
423                 unsigned long pfn, mfn;
424
425                 pfn = virt_to_pfn(va);
426                 mfn = pfn_to_mfn(pfn);
427
428                 pte = pfn_pte(pfn, PAGE_KERNEL_RO);
429
430                 if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0))
431                         BUG();
432
433                 frames[f] = mfn;
434         }
435
436         if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
437                 BUG();
438 }
439
440 static void load_TLS_descriptor(struct thread_struct *t,
441                                 unsigned int cpu, unsigned int i)
442 {
443         struct desc_struct *gdt = get_cpu_gdt_table(cpu);
444         xmaddr_t maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
445         struct multicall_space mc = __xen_mc_entry(0);
446
447         MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
448 }
449
450 static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
451 {
452         /*
453          * XXX sleazy hack: If we're being called in a lazy-cpu zone
454          * and lazy gs handling is enabled, it means we're in a
455          * context switch, and %gs has just been saved.  This means we
456          * can zero it out to prevent faults on exit from the
457          * hypervisor if the next process has no %gs.  Either way, it
458          * has been saved, and the new value will get loaded properly.
459          * This will go away as soon as Xen has been modified to not
460          * save/restore %gs for normal hypercalls.
461          *
462          * On x86_64, this hack is not used for %gs, because gs points
463          * to KERNEL_GS_BASE (and uses it for PDA references), so we
464          * must not zero %gs on x86_64
465          *
466          * For x86_64, we need to zero %fs, otherwise we may get an
467          * exception between the new %fs descriptor being loaded and
468          * %fs being effectively cleared at __switch_to().
469          */
470         if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
471 #ifdef CONFIG_X86_32
472                 lazy_load_gs(0);
473 #else
474                 loadsegment(fs, 0);
475 #endif
476         }
477
478         xen_mc_batch();
479
480         load_TLS_descriptor(t, cpu, 0);
481         load_TLS_descriptor(t, cpu, 1);
482         load_TLS_descriptor(t, cpu, 2);
483
484         xen_mc_issue(PARAVIRT_LAZY_CPU);
485 }
486
487 #ifdef CONFIG_X86_64
488 static void xen_load_gs_index(unsigned int idx)
489 {
490         if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
491                 BUG();
492 }
493 #endif
494
495 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
496                                 const void *ptr)
497 {
498         xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
499         u64 entry = *(u64 *)ptr;
500
501         trace_xen_cpu_write_ldt_entry(dt, entrynum, entry);
502
503         preempt_disable();
504
505         xen_mc_flush();
506         if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
507                 BUG();
508
509         preempt_enable();
510 }
511
512 static int cvt_gate_to_trap(int vector, const gate_desc *val,
513                             struct trap_info *info)
514 {
515         unsigned long addr;
516
517         if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT)
518                 return 0;
519
520         info->vector = vector;
521
522         addr = gate_offset(*val);
523 #ifdef CONFIG_X86_64
524         /*
525          * Look for known traps using IST, and substitute them
526          * appropriately.  The debugger ones are the only ones we care
527          * about.  Xen will handle faults like double_fault and
528          * machine_check, so we should never see them.  Warn if
529          * there's an unexpected IST-using fault handler.
530          */
531         if (addr == (unsigned long)debug)
532                 addr = (unsigned long)xen_debug;
533         else if (addr == (unsigned long)int3)
534                 addr = (unsigned long)xen_int3;
535         else if (addr == (unsigned long)stack_segment)
536                 addr = (unsigned long)xen_stack_segment;
537         else if (addr == (unsigned long)double_fault ||
538                  addr == (unsigned long)nmi) {
539                 /* Don't need to handle these */
540                 return 0;
541 #ifdef CONFIG_X86_MCE
542         } else if (addr == (unsigned long)machine_check) {
543                 return 0;
544 #endif
545         } else {
546                 /* Some other trap using IST? */
547                 if (WARN_ON(val->ist != 0))
548                         return 0;
549         }
550 #endif  /* CONFIG_X86_64 */
551         info->address = addr;
552
553         info->cs = gate_segment(*val);
554         info->flags = val->dpl;
555         /* interrupt gates clear IF */
556         if (val->type == GATE_INTERRUPT)
557                 info->flags |= 1 << 2;
558
559         return 1;
560 }
561
562 /* Locations of each CPU's IDT */
563 static DEFINE_PER_CPU(struct desc_ptr, idt_desc);
564
565 /* Set an IDT entry.  If the entry is part of the current IDT, then
566    also update Xen. */
567 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
568 {
569         unsigned long p = (unsigned long)&dt[entrynum];
570         unsigned long start, end;
571
572         trace_xen_cpu_write_idt_entry(dt, entrynum, g);
573
574         preempt_disable();
575
576         start = __this_cpu_read(idt_desc.address);
577         end = start + __this_cpu_read(idt_desc.size) + 1;
578
579         xen_mc_flush();
580
581         native_write_idt_entry(dt, entrynum, g);
582
583         if (p >= start && (p + 8) <= end) {
584                 struct trap_info info[2];
585
586                 info[1].address = 0;
587
588                 if (cvt_gate_to_trap(entrynum, g, &info[0]))
589                         if (HYPERVISOR_set_trap_table(info))
590                                 BUG();
591         }
592
593         preempt_enable();
594 }
595
596 static void xen_convert_trap_info(const struct desc_ptr *desc,
597                                   struct trap_info *traps)
598 {
599         unsigned in, out, count;
600
601         count = (desc->size+1) / sizeof(gate_desc);
602         BUG_ON(count > 256);
603
604         for (in = out = 0; in < count; in++) {
605                 gate_desc *entry = (gate_desc*)(desc->address) + in;
606
607                 if (cvt_gate_to_trap(in, entry, &traps[out]))
608                         out++;
609         }
610         traps[out].address = 0;
611 }
612
613 void xen_copy_trap_info(struct trap_info *traps)
614 {
615         const struct desc_ptr *desc = &__get_cpu_var(idt_desc);
616
617         xen_convert_trap_info(desc, traps);
618 }
619
620 /* Load a new IDT into Xen.  In principle this can be per-CPU, so we
621    hold a spinlock to protect the static traps[] array (static because
622    it avoids allocation, and saves stack space). */
623 static void xen_load_idt(const struct desc_ptr *desc)
624 {
625         static DEFINE_SPINLOCK(lock);
626         static struct trap_info traps[257];
627
628         trace_xen_cpu_load_idt(desc);
629
630         spin_lock(&lock);
631
632         __get_cpu_var(idt_desc) = *desc;
633
634         xen_convert_trap_info(desc, traps);
635
636         xen_mc_flush();
637         if (HYPERVISOR_set_trap_table(traps))
638                 BUG();
639
640         spin_unlock(&lock);
641 }
642
643 /* Write a GDT descriptor entry.  Ignore LDT descriptors, since
644    they're handled differently. */
645 static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
646                                 const void *desc, int type)
647 {
648         trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
649
650         preempt_disable();
651
652         switch (type) {
653         case DESC_LDT:
654         case DESC_TSS:
655                 /* ignore */
656                 break;
657
658         default: {
659                 xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]);
660
661                 xen_mc_flush();
662                 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
663                         BUG();
664         }
665
666         }
667
668         preempt_enable();
669 }
670
671 /*
672  * Version of write_gdt_entry for use at early boot-time needed to
673  * update an entry as simply as possible.
674  */
675 static void __init xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
676                                             const void *desc, int type)
677 {
678         trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
679
680         switch (type) {
681         case DESC_LDT:
682         case DESC_TSS:
683                 /* ignore */
684                 break;
685
686         default: {
687                 xmaddr_t maddr = virt_to_machine(&dt[entry]);
688
689                 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
690                         dt[entry] = *(struct desc_struct *)desc;
691         }
692
693         }
694 }
695
696 static void xen_load_sp0(struct tss_struct *tss,
697                          struct thread_struct *thread)
698 {
699         struct multicall_space mcs;
700
701         mcs = xen_mc_entry(0);
702         MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
703         xen_mc_issue(PARAVIRT_LAZY_CPU);
704 }
705
706 static void xen_set_iopl_mask(unsigned mask)
707 {
708         struct physdev_set_iopl set_iopl;
709
710         /* Force the change at ring 0. */
711         set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
712         HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
713 }
714
715 static void xen_io_delay(void)
716 {
717 }
718
719 #ifdef CONFIG_X86_LOCAL_APIC
720 static u32 xen_apic_read(u32 reg)
721 {
722         return 0;
723 }
724
725 static void xen_apic_write(u32 reg, u32 val)
726 {
727         /* Warn to see if there's any stray references */
728         WARN_ON(1);
729 }
730
731 static u64 xen_apic_icr_read(void)
732 {
733         return 0;
734 }
735
736 static void xen_apic_icr_write(u32 low, u32 id)
737 {
738         /* Warn to see if there's any stray references */
739         WARN_ON(1);
740 }
741
742 static void xen_apic_wait_icr_idle(void)
743 {
744         return;
745 }
746
747 static u32 xen_safe_apic_wait_icr_idle(void)
748 {
749         return 0;
750 }
751
752 static void set_xen_basic_apic_ops(void)
753 {
754         apic->read = xen_apic_read;
755         apic->write = xen_apic_write;
756         apic->icr_read = xen_apic_icr_read;
757         apic->icr_write = xen_apic_icr_write;
758         apic->wait_icr_idle = xen_apic_wait_icr_idle;
759         apic->safe_wait_icr_idle = xen_safe_apic_wait_icr_idle;
760 }
761
762 #endif
763
764 static void xen_clts(void)
765 {
766         struct multicall_space mcs;
767
768         mcs = xen_mc_entry(0);
769
770         MULTI_fpu_taskswitch(mcs.mc, 0);
771
772         xen_mc_issue(PARAVIRT_LAZY_CPU);
773 }
774
775 static DEFINE_PER_CPU(unsigned long, xen_cr0_value);
776
777 static unsigned long xen_read_cr0(void)
778 {
779         unsigned long cr0 = percpu_read(xen_cr0_value);
780
781         if (unlikely(cr0 == 0)) {
782                 cr0 = native_read_cr0();
783                 percpu_write(xen_cr0_value, cr0);
784         }
785
786         return cr0;
787 }
788
789 static void xen_write_cr0(unsigned long cr0)
790 {
791         struct multicall_space mcs;
792
793         percpu_write(xen_cr0_value, cr0);
794
795         /* Only pay attention to cr0.TS; everything else is
796            ignored. */
797         mcs = xen_mc_entry(0);
798
799         MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
800
801         xen_mc_issue(PARAVIRT_LAZY_CPU);
802 }
803
804 static void xen_write_cr4(unsigned long cr4)
805 {
806         cr4 &= ~X86_CR4_PGE;
807         cr4 &= ~X86_CR4_PSE;
808
809         native_write_cr4(cr4);
810 }
811
812 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
813 {
814         int ret;
815
816         ret = 0;
817
818         switch (msr) {
819 #ifdef CONFIG_X86_64
820                 unsigned which;
821                 u64 base;
822
823         case MSR_FS_BASE:               which = SEGBASE_FS; goto set;
824         case MSR_KERNEL_GS_BASE:        which = SEGBASE_GS_USER; goto set;
825         case MSR_GS_BASE:               which = SEGBASE_GS_KERNEL; goto set;
826
827         set:
828                 base = ((u64)high << 32) | low;
829                 if (HYPERVISOR_set_segment_base(which, base) != 0)
830                         ret = -EIO;
831                 break;
832 #endif
833
834         case MSR_STAR:
835         case MSR_CSTAR:
836         case MSR_LSTAR:
837         case MSR_SYSCALL_MASK:
838         case MSR_IA32_SYSENTER_CS:
839         case MSR_IA32_SYSENTER_ESP:
840         case MSR_IA32_SYSENTER_EIP:
841                 /* Fast syscall setup is all done in hypercalls, so
842                    these are all ignored.  Stub them out here to stop
843                    Xen console noise. */
844                 break;
845
846         case MSR_IA32_CR_PAT:
847                 if (smp_processor_id() == 0)
848                         xen_set_pat(((u64)high << 32) | low);
849                 break;
850
851         default:
852                 ret = native_write_msr_safe(msr, low, high);
853         }
854
855         return ret;
856 }
857
858 void xen_setup_shared_info(void)
859 {
860         if (!xen_feature(XENFEAT_auto_translated_physmap)) {
861                 set_fixmap(FIX_PARAVIRT_BOOTMAP,
862                            xen_start_info->shared_info);
863
864                 HYPERVISOR_shared_info =
865                         (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
866         } else
867                 HYPERVISOR_shared_info =
868                         (struct shared_info *)__va(xen_start_info->shared_info);
869
870 #ifndef CONFIG_SMP
871         /* In UP this is as good a place as any to set up shared info */
872         xen_setup_vcpu_info_placement();
873 #endif
874
875         xen_setup_mfn_list_list();
876 }
877
878 /* This is called once we have the cpu_possible_map */
879 void xen_setup_vcpu_info_placement(void)
880 {
881         int cpu;
882
883         for_each_possible_cpu(cpu)
884                 xen_vcpu_setup(cpu);
885
886         /* xen_vcpu_setup managed to place the vcpu_info within the
887            percpu area for all cpus, so make use of it */
888         if (have_vcpu_info_placement) {
889                 pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
890                 pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct);
891                 pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
892                 pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
893                 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
894         }
895 }
896
897 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
898                           unsigned long addr, unsigned len)
899 {
900         char *start, *end, *reloc;
901         unsigned ret;
902
903         start = end = reloc = NULL;
904
905 #define SITE(op, x)                                                     \
906         case PARAVIRT_PATCH(op.x):                                      \
907         if (have_vcpu_info_placement) {                                 \
908                 start = (char *)xen_##x##_direct;                       \
909                 end = xen_##x##_direct_end;                             \
910                 reloc = xen_##x##_direct_reloc;                         \
911         }                                                               \
912         goto patch_site
913
914         switch (type) {
915                 SITE(pv_irq_ops, irq_enable);
916                 SITE(pv_irq_ops, irq_disable);
917                 SITE(pv_irq_ops, save_fl);
918                 SITE(pv_irq_ops, restore_fl);
919 #undef SITE
920
921         patch_site:
922                 if (start == NULL || (end-start) > len)
923                         goto default_patch;
924
925                 ret = paravirt_patch_insns(insnbuf, len, start, end);
926
927                 /* Note: because reloc is assigned from something that
928                    appears to be an array, gcc assumes it's non-null,
929                    but doesn't know its relationship with start and
930                    end. */
931                 if (reloc > start && reloc < end) {
932                         int reloc_off = reloc - start;
933                         long *relocp = (long *)(insnbuf + reloc_off);
934                         long delta = start - (char *)addr;
935
936                         *relocp += delta;
937                 }
938                 break;
939
940         default_patch:
941         default:
942                 ret = paravirt_patch_default(type, clobbers, insnbuf,
943                                              addr, len);
944                 break;
945         }
946
947         return ret;
948 }
949
950 static const struct pv_info xen_info __initconst = {
951         .paravirt_enabled = 1,
952         .shared_kernel_pmd = 0,
953
954         .name = "Xen",
955 };
956
957 static const struct pv_init_ops xen_init_ops __initconst = {
958         .patch = xen_patch,
959 };
960
961 static const struct pv_cpu_ops xen_cpu_ops __initconst = {
962         .cpuid = xen_cpuid,
963
964         .set_debugreg = xen_set_debugreg,
965         .get_debugreg = xen_get_debugreg,
966
967         .clts = xen_clts,
968
969         .read_cr0 = xen_read_cr0,
970         .write_cr0 = xen_write_cr0,
971
972         .read_cr4 = native_read_cr4,
973         .read_cr4_safe = native_read_cr4_safe,
974         .write_cr4 = xen_write_cr4,
975
976         .wbinvd = native_wbinvd,
977
978         .read_msr = native_read_msr_safe,
979         .write_msr = xen_write_msr_safe,
980         .read_tsc = native_read_tsc,
981         .read_pmc = native_read_pmc,
982
983         .iret = xen_iret,
984         .irq_enable_sysexit = xen_sysexit,
985 #ifdef CONFIG_X86_64
986         .usergs_sysret32 = xen_sysret32,
987         .usergs_sysret64 = xen_sysret64,
988 #endif
989
990         .load_tr_desc = paravirt_nop,
991         .set_ldt = xen_set_ldt,
992         .load_gdt = xen_load_gdt,
993         .load_idt = xen_load_idt,
994         .load_tls = xen_load_tls,
995 #ifdef CONFIG_X86_64
996         .load_gs_index = xen_load_gs_index,
997 #endif
998
999         .alloc_ldt = xen_alloc_ldt,
1000         .free_ldt = xen_free_ldt,
1001
1002         .store_gdt = native_store_gdt,
1003         .store_idt = native_store_idt,
1004         .store_tr = xen_store_tr,
1005
1006         .write_ldt_entry = xen_write_ldt_entry,
1007         .write_gdt_entry = xen_write_gdt_entry,
1008         .write_idt_entry = xen_write_idt_entry,
1009         .load_sp0 = xen_load_sp0,
1010
1011         .set_iopl_mask = xen_set_iopl_mask,
1012         .io_delay = xen_io_delay,
1013
1014         /* Xen takes care of %gs when switching to usermode for us */
1015         .swapgs = paravirt_nop,
1016
1017         .start_context_switch = paravirt_start_context_switch,
1018         .end_context_switch = xen_end_context_switch,
1019 };
1020
1021 static const struct pv_apic_ops xen_apic_ops __initconst = {
1022 #ifdef CONFIG_X86_LOCAL_APIC
1023         .startup_ipi_hook = paravirt_nop,
1024 #endif
1025 };
1026
1027 static void xen_reboot(int reason)
1028 {
1029         struct sched_shutdown r = { .reason = reason };
1030
1031         if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
1032                 BUG();
1033 }
1034
1035 static void xen_restart(char *msg)
1036 {
1037         xen_reboot(SHUTDOWN_reboot);
1038 }
1039
1040 static void xen_emergency_restart(void)
1041 {
1042         xen_reboot(SHUTDOWN_reboot);
1043 }
1044
1045 static void xen_machine_halt(void)
1046 {
1047         xen_reboot(SHUTDOWN_poweroff);
1048 }
1049
1050 static void xen_machine_power_off(void)
1051 {
1052         if (pm_power_off)
1053                 pm_power_off();
1054         xen_reboot(SHUTDOWN_poweroff);
1055 }
1056
1057 static void xen_crash_shutdown(struct pt_regs *regs)
1058 {
1059         xen_reboot(SHUTDOWN_crash);
1060 }
1061
1062 static int
1063 xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
1064 {
1065         xen_reboot(SHUTDOWN_crash);
1066         return NOTIFY_DONE;
1067 }
1068
1069 static struct notifier_block xen_panic_block = {
1070         .notifier_call= xen_panic_event,
1071 };
1072
1073 int xen_panic_handler_init(void)
1074 {
1075         atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block);
1076         return 0;
1077 }
1078
1079 static const struct machine_ops xen_machine_ops __initconst = {
1080         .restart = xen_restart,
1081         .halt = xen_machine_halt,
1082         .power_off = xen_machine_power_off,
1083         .shutdown = xen_machine_halt,
1084         .crash_shutdown = xen_crash_shutdown,
1085         .emergency_restart = xen_emergency_restart,
1086 };
1087
1088 /*
1089  * Set up the GDT and segment registers for -fstack-protector.  Until
1090  * we do this, we have to be careful not to call any stack-protected
1091  * function, which is most of the kernel.
1092  */
1093 static void __init xen_setup_stackprotector(void)
1094 {
1095         pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
1096         pv_cpu_ops.load_gdt = xen_load_gdt_boot;
1097
1098         setup_stack_canary_segment(0);
1099         switch_to_new_gdt(0);
1100
1101         pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry;
1102         pv_cpu_ops.load_gdt = xen_load_gdt;
1103 }
1104
1105 /* First C function to be called on Xen boot */
1106 asmlinkage void __init xen_start_kernel(void)
1107 {
1108         struct physdev_set_iopl set_iopl;
1109         int rc;
1110         pgd_t *pgd;
1111
1112         if (!xen_start_info)
1113                 return;
1114
1115         xen_domain_type = XEN_PV_DOMAIN;
1116
1117         xen_setup_machphys_mapping();
1118
1119         /* Install Xen paravirt ops */
1120         pv_info = xen_info;
1121         pv_init_ops = xen_init_ops;
1122         pv_cpu_ops = xen_cpu_ops;
1123         pv_apic_ops = xen_apic_ops;
1124
1125         x86_init.resources.memory_setup = xen_memory_setup;
1126         x86_init.oem.arch_setup = xen_arch_setup;
1127         x86_init.oem.banner = xen_banner;
1128
1129         xen_init_time_ops();
1130
1131         /*
1132          * Set up some pagetable state before starting to set any ptes.
1133          */
1134
1135         xen_init_mmu_ops();
1136
1137         /* Prevent unwanted bits from being set in PTEs. */
1138         __supported_pte_mask &= ~_PAGE_GLOBAL;
1139         if (!xen_initial_domain())
1140                 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
1141
1142         __supported_pte_mask |= _PAGE_IOMAP;
1143
1144         /*
1145          * Prevent page tables from being allocated in highmem, even
1146          * if CONFIG_HIGHPTE is enabled.
1147          */
1148         __userpte_alloc_gfp &= ~__GFP_HIGHMEM;
1149
1150         /* Work out if we support NX */
1151         x86_configure_nx();
1152
1153         xen_setup_features();
1154
1155         /* Get mfn list */
1156         if (!xen_feature(XENFEAT_auto_translated_physmap))
1157                 xen_build_dynamic_phys_to_machine();
1158
1159         /*
1160          * Set up kernel GDT and segment registers, mainly so that
1161          * -fstack-protector code can be executed.
1162          */
1163         xen_setup_stackprotector();
1164
1165         xen_init_irq_ops();
1166         xen_init_cpuid_mask();
1167
1168 #ifdef CONFIG_X86_LOCAL_APIC
1169         /*
1170          * set up the basic apic ops.
1171          */
1172         set_xen_basic_apic_ops();
1173 #endif
1174
1175         if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
1176                 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
1177                 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
1178         }
1179
1180         machine_ops = xen_machine_ops;
1181
1182         /*
1183          * The only reliable way to retain the initial address of the
1184          * percpu gdt_page is to remember it here, so we can go and
1185          * mark it RW later, when the initial percpu area is freed.
1186          */
1187         xen_initial_gdt = &per_cpu(gdt_page, 0);
1188
1189         xen_smp_init();
1190
1191 #ifdef CONFIG_ACPI_NUMA
1192         /*
1193          * The pages we from Xen are not related to machine pages, so
1194          * any NUMA information the kernel tries to get from ACPI will
1195          * be meaningless.  Prevent it from trying.
1196          */
1197         acpi_numa = -1;
1198 #endif
1199
1200         pgd = (pgd_t *)xen_start_info->pt_base;
1201
1202         if (!xen_initial_domain())
1203                 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
1204
1205         __supported_pte_mask |= _PAGE_IOMAP;
1206         /* Don't do the full vcpu_info placement stuff until we have a
1207            possible map and a non-dummy shared_info. */
1208         per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1209
1210         local_irq_disable();
1211         early_boot_irqs_disabled = true;
1212
1213         memblock_init();
1214
1215         xen_raw_console_write("mapping kernel into physical memory\n");
1216         pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages);
1217         xen_ident_map_ISA();
1218
1219         /* Allocate and initialize top and mid mfn levels for p2m structure */
1220         xen_build_mfn_list_list();
1221
1222         /* keep using Xen gdt for now; no urgent need to change it */
1223
1224 #ifdef CONFIG_X86_32
1225         pv_info.kernel_rpl = 1;
1226         if (xen_feature(XENFEAT_supervisor_mode_kernel))
1227                 pv_info.kernel_rpl = 0;
1228 #else
1229         pv_info.kernel_rpl = 0;
1230 #endif
1231         /* set the limit of our address space */
1232         xen_reserve_top();
1233
1234         /* We used to do this in xen_arch_setup, but that is too late on AMD
1235          * were early_cpu_init (run before ->arch_setup()) calls early_amd_init
1236          * which pokes 0xcf8 port.
1237          */
1238         set_iopl.iopl = 1;
1239         rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
1240         if (rc != 0)
1241                 xen_raw_printk("physdev_op failed %d\n", rc);
1242
1243 #ifdef CONFIG_X86_32
1244         /* set up basic CPUID stuff */
1245         cpu_detect(&new_cpu_data);
1246         new_cpu_data.hard_math = 1;
1247         new_cpu_data.wp_works_ok = 1;
1248         new_cpu_data.x86_capability[0] = cpuid_edx(1);
1249 #endif
1250
1251         /* Poke various useful things into boot_params */
1252         boot_params.hdr.type_of_loader = (9 << 4) | 0;
1253         boot_params.hdr.ramdisk_image = xen_start_info->mod_start
1254                 ? __pa(xen_start_info->mod_start) : 0;
1255         boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
1256         boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
1257
1258         if (!xen_initial_domain()) {
1259                 add_preferred_console("xenboot", 0, NULL);
1260                 add_preferred_console("tty", 0, NULL);
1261                 add_preferred_console("hvc", 0, NULL);
1262                 if (pci_xen)
1263                         x86_init.pci.arch_init = pci_xen_init;
1264         } else {
1265                 const struct dom0_vga_console_info *info =
1266                         (void *)((char *)xen_start_info +
1267                                  xen_start_info->console.dom0.info_off);
1268
1269                 xen_init_vga(info, xen_start_info->console.dom0.info_size);
1270                 xen_start_info->console.domU.mfn = 0;
1271                 xen_start_info->console.domU.evtchn = 0;
1272
1273                 /* Make sure ACS will be enabled */
1274                 pci_request_acs();
1275         }
1276                 
1277
1278         xen_raw_console_write("about to get started...\n");
1279
1280         xen_setup_runstate_info(0);
1281
1282         /* Start the world */
1283 #ifdef CONFIG_X86_32
1284         i386_start_kernel();
1285 #else
1286         x86_64_start_reservations((char *)__pa_symbol(&boot_params));
1287 #endif
1288 }
1289
1290 static int init_hvm_pv_info(int *major, int *minor)
1291 {
1292         uint32_t eax, ebx, ecx, edx, pages, msr, base;
1293         u64 pfn;
1294
1295         base = xen_cpuid_base();
1296         cpuid(base + 1, &eax, &ebx, &ecx, &edx);
1297
1298         *major = eax >> 16;
1299         *minor = eax & 0xffff;
1300         printk(KERN_INFO "Xen version %d.%d.\n", *major, *minor);
1301
1302         cpuid(base + 2, &pages, &msr, &ecx, &edx);
1303
1304         pfn = __pa(hypercall_page);
1305         wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
1306
1307         xen_setup_features();
1308
1309         pv_info.name = "Xen HVM";
1310
1311         xen_domain_type = XEN_HVM_DOMAIN;
1312
1313         return 0;
1314 }
1315
1316 void __ref xen_hvm_init_shared_info(void)
1317 {
1318         int cpu;
1319         struct xen_add_to_physmap xatp;
1320         static struct shared_info *shared_info_page = 0;
1321
1322         if (!shared_info_page)
1323                 shared_info_page = (struct shared_info *)
1324                         extend_brk(PAGE_SIZE, PAGE_SIZE);
1325         xatp.domid = DOMID_SELF;
1326         xatp.idx = 0;
1327         xatp.space = XENMAPSPACE_shared_info;
1328         xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
1329         if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
1330                 BUG();
1331
1332         HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
1333
1334         /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
1335          * page, we use it in the event channel upcall and in some pvclock
1336          * related functions. We don't need the vcpu_info placement
1337          * optimizations because we don't use any pv_mmu or pv_irq op on
1338          * HVM.
1339          * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
1340          * online but xen_hvm_init_shared_info is run at resume time too and
1341          * in that case multiple vcpus might be online. */
1342         for_each_online_cpu(cpu) {
1343                 per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
1344         }
1345 }
1346
1347 #ifdef CONFIG_XEN_PVHVM
1348 static int __cpuinit xen_hvm_cpu_notify(struct notifier_block *self,
1349                                     unsigned long action, void *hcpu)
1350 {
1351         int cpu = (long)hcpu;
1352         switch (action) {
1353         case CPU_UP_PREPARE:
1354                 per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
1355                 if (xen_have_vector_callback)
1356                         xen_init_lock_cpu(cpu);
1357                 break;
1358         default:
1359                 break;
1360         }
1361         return NOTIFY_OK;
1362 }
1363
1364 static struct notifier_block xen_hvm_cpu_notifier __cpuinitdata = {
1365         .notifier_call  = xen_hvm_cpu_notify,
1366 };
1367
1368 static void __init xen_hvm_guest_init(void)
1369 {
1370         int r;
1371         int major, minor;
1372
1373         r = init_hvm_pv_info(&major, &minor);
1374         if (r < 0)
1375                 return;
1376
1377         xen_hvm_init_shared_info();
1378
1379         if (xen_feature(XENFEAT_hvm_callback_vector))
1380                 xen_have_vector_callback = 1;
1381         xen_hvm_smp_init();
1382         register_cpu_notifier(&xen_hvm_cpu_notifier);
1383         xen_unplug_emulated_devices();
1384         have_vcpu_info_placement = 0;
1385         x86_init.irqs.intr_init = xen_init_IRQ;
1386         xen_hvm_init_time_ops();
1387         xen_hvm_init_mmu_ops();
1388 }
1389
1390 static bool __init xen_hvm_platform(void)
1391 {
1392         if (xen_pv_domain())
1393                 return false;
1394
1395         if (!xen_cpuid_base())
1396                 return false;
1397
1398         return true;
1399 }
1400
1401 bool xen_hvm_need_lapic(void)
1402 {
1403         if (xen_pv_domain())
1404                 return false;
1405         if (!xen_hvm_domain())
1406                 return false;
1407         if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
1408                 return false;
1409         return true;
1410 }
1411 EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
1412
1413 const struct hypervisor_x86 x86_hyper_xen_hvm __refconst = {
1414         .name                   = "Xen HVM",
1415         .detect                 = xen_hvm_platform,
1416         .init_platform          = xen_hvm_guest_init,
1417 };
1418 EXPORT_SYMBOL(x86_hyper_xen_hvm);
1419 #endif