1f928659c338e6e5cfcf6386446f087f41f1e22f
[linux-2.6.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 long  machine_to_phys_nr;
81 EXPORT_SYMBOL(machine_to_phys_nr);
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         cx = 0;
255         xen_cpuid(&ax, &bx, &cx, &dx);
256
257         xsave_mask =
258                 (1 << (X86_FEATURE_XSAVE % 32)) |
259                 (1 << (X86_FEATURE_OSXSAVE % 32));
260
261         /* Xen will set CR4.OSXSAVE if supported and not disabled by force */
262         if ((cx & xsave_mask) != xsave_mask)
263                 cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */
264 }
265
266 static void xen_set_debugreg(int reg, unsigned long val)
267 {
268         HYPERVISOR_set_debugreg(reg, val);
269 }
270
271 static unsigned long xen_get_debugreg(int reg)
272 {
273         return HYPERVISOR_get_debugreg(reg);
274 }
275
276 static void xen_end_context_switch(struct task_struct *next)
277 {
278         xen_mc_flush();
279         paravirt_end_context_switch(next);
280 }
281
282 static unsigned long xen_store_tr(void)
283 {
284         return 0;
285 }
286
287 /*
288  * Set the page permissions for a particular virtual address.  If the
289  * address is a vmalloc mapping (or other non-linear mapping), then
290  * find the linear mapping of the page and also set its protections to
291  * match.
292  */
293 static void set_aliased_prot(void *v, pgprot_t prot)
294 {
295         int level;
296         pte_t *ptep;
297         pte_t pte;
298         unsigned long pfn;
299         struct page *page;
300
301         ptep = lookup_address((unsigned long)v, &level);
302         BUG_ON(ptep == NULL);
303
304         pfn = pte_pfn(*ptep);
305         page = pfn_to_page(pfn);
306
307         pte = pfn_pte(pfn, prot);
308
309         if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
310                 BUG();
311
312         if (!PageHighMem(page)) {
313                 void *av = __va(PFN_PHYS(pfn));
314
315                 if (av != v)
316                         if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
317                                 BUG();
318         } else
319                 kmap_flush_unused();
320 }
321
322 static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
323 {
324         const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
325         int i;
326
327         for(i = 0; i < entries; i += entries_per_page)
328                 set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
329 }
330
331 static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
332 {
333         const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
334         int i;
335
336         for(i = 0; i < entries; i += entries_per_page)
337                 set_aliased_prot(ldt + i, PAGE_KERNEL);
338 }
339
340 static void xen_set_ldt(const void *addr, unsigned entries)
341 {
342         struct mmuext_op *op;
343         struct multicall_space mcs = xen_mc_entry(sizeof(*op));
344
345         trace_xen_cpu_set_ldt(addr, entries);
346
347         op = mcs.args;
348         op->cmd = MMUEXT_SET_LDT;
349         op->arg1.linear_addr = (unsigned long)addr;
350         op->arg2.nr_ents = entries;
351
352         MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
353
354         xen_mc_issue(PARAVIRT_LAZY_CPU);
355 }
356
357 static void xen_load_gdt(const struct desc_ptr *dtr)
358 {
359         unsigned long va = dtr->address;
360         unsigned int size = dtr->size + 1;
361         unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
362         unsigned long frames[pages];
363         int f;
364
365         /*
366          * A GDT can be up to 64k in size, which corresponds to 8192
367          * 8-byte entries, or 16 4k pages..
368          */
369
370         BUG_ON(size > 65536);
371         BUG_ON(va & ~PAGE_MASK);
372
373         for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
374                 int level;
375                 pte_t *ptep;
376                 unsigned long pfn, mfn;
377                 void *virt;
378
379                 /*
380                  * The GDT is per-cpu and is in the percpu data area.
381                  * That can be virtually mapped, so we need to do a
382                  * page-walk to get the underlying MFN for the
383                  * hypercall.  The page can also be in the kernel's
384                  * linear range, so we need to RO that mapping too.
385                  */
386                 ptep = lookup_address(va, &level);
387                 BUG_ON(ptep == NULL);
388
389                 pfn = pte_pfn(*ptep);
390                 mfn = pfn_to_mfn(pfn);
391                 virt = __va(PFN_PHYS(pfn));
392
393                 frames[f] = mfn;
394
395                 make_lowmem_page_readonly((void *)va);
396                 make_lowmem_page_readonly(virt);
397         }
398
399         if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
400                 BUG();
401 }
402
403 /*
404  * load_gdt for early boot, when the gdt is only mapped once
405  */
406 static void __init xen_load_gdt_boot(const struct desc_ptr *dtr)
407 {
408         unsigned long va = dtr->address;
409         unsigned int size = dtr->size + 1;
410         unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
411         unsigned long frames[pages];
412         int f;
413
414         /*
415          * A GDT can be up to 64k in size, which corresponds to 8192
416          * 8-byte entries, or 16 4k pages..
417          */
418
419         BUG_ON(size > 65536);
420         BUG_ON(va & ~PAGE_MASK);
421
422         for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
423                 pte_t pte;
424                 unsigned long pfn, mfn;
425
426                 pfn = virt_to_pfn(va);
427                 mfn = pfn_to_mfn(pfn);
428
429                 pte = pfn_pte(pfn, PAGE_KERNEL_RO);
430
431                 if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0))
432                         BUG();
433
434                 frames[f] = mfn;
435         }
436
437         if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
438                 BUG();
439 }
440
441 static void load_TLS_descriptor(struct thread_struct *t,
442                                 unsigned int cpu, unsigned int i)
443 {
444         struct desc_struct *gdt = get_cpu_gdt_table(cpu);
445         xmaddr_t maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
446         struct multicall_space mc = __xen_mc_entry(0);
447
448         MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
449 }
450
451 static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
452 {
453         /*
454          * XXX sleazy hack: If we're being called in a lazy-cpu zone
455          * and lazy gs handling is enabled, it means we're in a
456          * context switch, and %gs has just been saved.  This means we
457          * can zero it out to prevent faults on exit from the
458          * hypervisor if the next process has no %gs.  Either way, it
459          * has been saved, and the new value will get loaded properly.
460          * This will go away as soon as Xen has been modified to not
461          * save/restore %gs for normal hypercalls.
462          *
463          * On x86_64, this hack is not used for %gs, because gs points
464          * to KERNEL_GS_BASE (and uses it for PDA references), so we
465          * must not zero %gs on x86_64
466          *
467          * For x86_64, we need to zero %fs, otherwise we may get an
468          * exception between the new %fs descriptor being loaded and
469          * %fs being effectively cleared at __switch_to().
470          */
471         if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
472 #ifdef CONFIG_X86_32
473                 lazy_load_gs(0);
474 #else
475                 loadsegment(fs, 0);
476 #endif
477         }
478
479         xen_mc_batch();
480
481         load_TLS_descriptor(t, cpu, 0);
482         load_TLS_descriptor(t, cpu, 1);
483         load_TLS_descriptor(t, cpu, 2);
484
485         xen_mc_issue(PARAVIRT_LAZY_CPU);
486 }
487
488 #ifdef CONFIG_X86_64
489 static void xen_load_gs_index(unsigned int idx)
490 {
491         if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
492                 BUG();
493 }
494 #endif
495
496 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
497                                 const void *ptr)
498 {
499         xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
500         u64 entry = *(u64 *)ptr;
501
502         trace_xen_cpu_write_ldt_entry(dt, entrynum, entry);
503
504         preempt_disable();
505
506         xen_mc_flush();
507         if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
508                 BUG();
509
510         preempt_enable();
511 }
512
513 static int cvt_gate_to_trap(int vector, const gate_desc *val,
514                             struct trap_info *info)
515 {
516         unsigned long addr;
517
518         if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT)
519                 return 0;
520
521         info->vector = vector;
522
523         addr = gate_offset(*val);
524 #ifdef CONFIG_X86_64
525         /*
526          * Look for known traps using IST, and substitute them
527          * appropriately.  The debugger ones are the only ones we care
528          * about.  Xen will handle faults like double_fault and
529          * machine_check, so we should never see them.  Warn if
530          * there's an unexpected IST-using fault handler.
531          */
532         if (addr == (unsigned long)debug)
533                 addr = (unsigned long)xen_debug;
534         else if (addr == (unsigned long)int3)
535                 addr = (unsigned long)xen_int3;
536         else if (addr == (unsigned long)stack_segment)
537                 addr = (unsigned long)xen_stack_segment;
538         else if (addr == (unsigned long)double_fault ||
539                  addr == (unsigned long)nmi) {
540                 /* Don't need to handle these */
541                 return 0;
542 #ifdef CONFIG_X86_MCE
543         } else if (addr == (unsigned long)machine_check) {
544                 return 0;
545 #endif
546         } else {
547                 /* Some other trap using IST? */
548                 if (WARN_ON(val->ist != 0))
549                         return 0;
550         }
551 #endif  /* CONFIG_X86_64 */
552         info->address = addr;
553
554         info->cs = gate_segment(*val);
555         info->flags = val->dpl;
556         /* interrupt gates clear IF */
557         if (val->type == GATE_INTERRUPT)
558                 info->flags |= 1 << 2;
559
560         return 1;
561 }
562
563 /* Locations of each CPU's IDT */
564 static DEFINE_PER_CPU(struct desc_ptr, idt_desc);
565
566 /* Set an IDT entry.  If the entry is part of the current IDT, then
567    also update Xen. */
568 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
569 {
570         unsigned long p = (unsigned long)&dt[entrynum];
571         unsigned long start, end;
572
573         trace_xen_cpu_write_idt_entry(dt, entrynum, g);
574
575         preempt_disable();
576
577         start = __this_cpu_read(idt_desc.address);
578         end = start + __this_cpu_read(idt_desc.size) + 1;
579
580         xen_mc_flush();
581
582         native_write_idt_entry(dt, entrynum, g);
583
584         if (p >= start && (p + 8) <= end) {
585                 struct trap_info info[2];
586
587                 info[1].address = 0;
588
589                 if (cvt_gate_to_trap(entrynum, g, &info[0]))
590                         if (HYPERVISOR_set_trap_table(info))
591                                 BUG();
592         }
593
594         preempt_enable();
595 }
596
597 static void xen_convert_trap_info(const struct desc_ptr *desc,
598                                   struct trap_info *traps)
599 {
600         unsigned in, out, count;
601
602         count = (desc->size+1) / sizeof(gate_desc);
603         BUG_ON(count > 256);
604
605         for (in = out = 0; in < count; in++) {
606                 gate_desc *entry = (gate_desc*)(desc->address) + in;
607
608                 if (cvt_gate_to_trap(in, entry, &traps[out]))
609                         out++;
610         }
611         traps[out].address = 0;
612 }
613
614 void xen_copy_trap_info(struct trap_info *traps)
615 {
616         const struct desc_ptr *desc = &__get_cpu_var(idt_desc);
617
618         xen_convert_trap_info(desc, traps);
619 }
620
621 /* Load a new IDT into Xen.  In principle this can be per-CPU, so we
622    hold a spinlock to protect the static traps[] array (static because
623    it avoids allocation, and saves stack space). */
624 static void xen_load_idt(const struct desc_ptr *desc)
625 {
626         static DEFINE_SPINLOCK(lock);
627         static struct trap_info traps[257];
628
629         trace_xen_cpu_load_idt(desc);
630
631         spin_lock(&lock);
632
633         __get_cpu_var(idt_desc) = *desc;
634
635         xen_convert_trap_info(desc, traps);
636
637         xen_mc_flush();
638         if (HYPERVISOR_set_trap_table(traps))
639                 BUG();
640
641         spin_unlock(&lock);
642 }
643
644 /* Write a GDT descriptor entry.  Ignore LDT descriptors, since
645    they're handled differently. */
646 static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
647                                 const void *desc, int type)
648 {
649         trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
650
651         preempt_disable();
652
653         switch (type) {
654         case DESC_LDT:
655         case DESC_TSS:
656                 /* ignore */
657                 break;
658
659         default: {
660                 xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]);
661
662                 xen_mc_flush();
663                 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
664                         BUG();
665         }
666
667         }
668
669         preempt_enable();
670 }
671
672 /*
673  * Version of write_gdt_entry for use at early boot-time needed to
674  * update an entry as simply as possible.
675  */
676 static void __init xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
677                                             const void *desc, int type)
678 {
679         trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
680
681         switch (type) {
682         case DESC_LDT:
683         case DESC_TSS:
684                 /* ignore */
685                 break;
686
687         default: {
688                 xmaddr_t maddr = virt_to_machine(&dt[entry]);
689
690                 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
691                         dt[entry] = *(struct desc_struct *)desc;
692         }
693
694         }
695 }
696
697 static void xen_load_sp0(struct tss_struct *tss,
698                          struct thread_struct *thread)
699 {
700         struct multicall_space mcs;
701
702         mcs = xen_mc_entry(0);
703         MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
704         xen_mc_issue(PARAVIRT_LAZY_CPU);
705 }
706
707 static void xen_set_iopl_mask(unsigned mask)
708 {
709         struct physdev_set_iopl set_iopl;
710
711         /* Force the change at ring 0. */
712         set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
713         HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
714 }
715
716 static void xen_io_delay(void)
717 {
718 }
719
720 #ifdef CONFIG_X86_LOCAL_APIC
721 static u32 xen_apic_read(u32 reg)
722 {
723         return 0;
724 }
725
726 static void xen_apic_write(u32 reg, u32 val)
727 {
728         /* Warn to see if there's any stray references */
729         WARN_ON(1);
730 }
731
732 static u64 xen_apic_icr_read(void)
733 {
734         return 0;
735 }
736
737 static void xen_apic_icr_write(u32 low, u32 id)
738 {
739         /* Warn to see if there's any stray references */
740         WARN_ON(1);
741 }
742
743 static void xen_apic_wait_icr_idle(void)
744 {
745         return;
746 }
747
748 static u32 xen_safe_apic_wait_icr_idle(void)
749 {
750         return 0;
751 }
752
753 static void set_xen_basic_apic_ops(void)
754 {
755         apic->read = xen_apic_read;
756         apic->write = xen_apic_write;
757         apic->icr_read = xen_apic_icr_read;
758         apic->icr_write = xen_apic_icr_write;
759         apic->wait_icr_idle = xen_apic_wait_icr_idle;
760         apic->safe_wait_icr_idle = xen_safe_apic_wait_icr_idle;
761 }
762
763 #endif
764
765 static void xen_clts(void)
766 {
767         struct multicall_space mcs;
768
769         mcs = xen_mc_entry(0);
770
771         MULTI_fpu_taskswitch(mcs.mc, 0);
772
773         xen_mc_issue(PARAVIRT_LAZY_CPU);
774 }
775
776 static DEFINE_PER_CPU(unsigned long, xen_cr0_value);
777
778 static unsigned long xen_read_cr0(void)
779 {
780         unsigned long cr0 = percpu_read(xen_cr0_value);
781
782         if (unlikely(cr0 == 0)) {
783                 cr0 = native_read_cr0();
784                 percpu_write(xen_cr0_value, cr0);
785         }
786
787         return cr0;
788 }
789
790 static void xen_write_cr0(unsigned long cr0)
791 {
792         struct multicall_space mcs;
793
794         percpu_write(xen_cr0_value, cr0);
795
796         /* Only pay attention to cr0.TS; everything else is
797            ignored. */
798         mcs = xen_mc_entry(0);
799
800         MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
801
802         xen_mc_issue(PARAVIRT_LAZY_CPU);
803 }
804
805 static void xen_write_cr4(unsigned long cr4)
806 {
807         cr4 &= ~X86_CR4_PGE;
808         cr4 &= ~X86_CR4_PSE;
809
810         native_write_cr4(cr4);
811 }
812
813 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
814 {
815         int ret;
816
817         ret = 0;
818
819         switch (msr) {
820 #ifdef CONFIG_X86_64
821                 unsigned which;
822                 u64 base;
823
824         case MSR_FS_BASE:               which = SEGBASE_FS; goto set;
825         case MSR_KERNEL_GS_BASE:        which = SEGBASE_GS_USER; goto set;
826         case MSR_GS_BASE:               which = SEGBASE_GS_KERNEL; goto set;
827
828         set:
829                 base = ((u64)high << 32) | low;
830                 if (HYPERVISOR_set_segment_base(which, base) != 0)
831                         ret = -EIO;
832                 break;
833 #endif
834
835         case MSR_STAR:
836         case MSR_CSTAR:
837         case MSR_LSTAR:
838         case MSR_SYSCALL_MASK:
839         case MSR_IA32_SYSENTER_CS:
840         case MSR_IA32_SYSENTER_ESP:
841         case MSR_IA32_SYSENTER_EIP:
842                 /* Fast syscall setup is all done in hypercalls, so
843                    these are all ignored.  Stub them out here to stop
844                    Xen console noise. */
845                 break;
846
847         case MSR_IA32_CR_PAT:
848                 if (smp_processor_id() == 0)
849                         xen_set_pat(((u64)high << 32) | low);
850                 break;
851
852         default:
853                 ret = native_write_msr_safe(msr, low, high);
854         }
855
856         return ret;
857 }
858
859 void xen_setup_shared_info(void)
860 {
861         if (!xen_feature(XENFEAT_auto_translated_physmap)) {
862                 set_fixmap(FIX_PARAVIRT_BOOTMAP,
863                            xen_start_info->shared_info);
864
865                 HYPERVISOR_shared_info =
866                         (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
867         } else
868                 HYPERVISOR_shared_info =
869                         (struct shared_info *)__va(xen_start_info->shared_info);
870
871 #ifndef CONFIG_SMP
872         /* In UP this is as good a place as any to set up shared info */
873         xen_setup_vcpu_info_placement();
874 #endif
875
876         xen_setup_mfn_list_list();
877 }
878
879 /* This is called once we have the cpu_possible_map */
880 void xen_setup_vcpu_info_placement(void)
881 {
882         int cpu;
883
884         for_each_possible_cpu(cpu)
885                 xen_vcpu_setup(cpu);
886
887         /* xen_vcpu_setup managed to place the vcpu_info within the
888            percpu area for all cpus, so make use of it */
889         if (have_vcpu_info_placement) {
890                 pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
891                 pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct);
892                 pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
893                 pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
894                 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
895         }
896 }
897
898 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
899                           unsigned long addr, unsigned len)
900 {
901         char *start, *end, *reloc;
902         unsigned ret;
903
904         start = end = reloc = NULL;
905
906 #define SITE(op, x)                                                     \
907         case PARAVIRT_PATCH(op.x):                                      \
908         if (have_vcpu_info_placement) {                                 \
909                 start = (char *)xen_##x##_direct;                       \
910                 end = xen_##x##_direct_end;                             \
911                 reloc = xen_##x##_direct_reloc;                         \
912         }                                                               \
913         goto patch_site
914
915         switch (type) {
916                 SITE(pv_irq_ops, irq_enable);
917                 SITE(pv_irq_ops, irq_disable);
918                 SITE(pv_irq_ops, save_fl);
919                 SITE(pv_irq_ops, restore_fl);
920 #undef SITE
921
922         patch_site:
923                 if (start == NULL || (end-start) > len)
924                         goto default_patch;
925
926                 ret = paravirt_patch_insns(insnbuf, len, start, end);
927
928                 /* Note: because reloc is assigned from something that
929                    appears to be an array, gcc assumes it's non-null,
930                    but doesn't know its relationship with start and
931                    end. */
932                 if (reloc > start && reloc < end) {
933                         int reloc_off = reloc - start;
934                         long *relocp = (long *)(insnbuf + reloc_off);
935                         long delta = start - (char *)addr;
936
937                         *relocp += delta;
938                 }
939                 break;
940
941         default_patch:
942         default:
943                 ret = paravirt_patch_default(type, clobbers, insnbuf,
944                                              addr, len);
945                 break;
946         }
947
948         return ret;
949 }
950
951 static const struct pv_info xen_info __initconst = {
952         .paravirt_enabled = 1,
953         .shared_kernel_pmd = 0,
954
955 #ifdef CONFIG_X86_64
956         .extra_user_64bit_cs = FLAT_USER_CS64,
957 #endif
958
959         .name = "Xen",
960 };
961
962 static const struct pv_init_ops xen_init_ops __initconst = {
963         .patch = xen_patch,
964 };
965
966 static const struct pv_cpu_ops xen_cpu_ops __initconst = {
967         .cpuid = xen_cpuid,
968
969         .set_debugreg = xen_set_debugreg,
970         .get_debugreg = xen_get_debugreg,
971
972         .clts = xen_clts,
973
974         .read_cr0 = xen_read_cr0,
975         .write_cr0 = xen_write_cr0,
976
977         .read_cr4 = native_read_cr4,
978         .read_cr4_safe = native_read_cr4_safe,
979         .write_cr4 = xen_write_cr4,
980
981         .wbinvd = native_wbinvd,
982
983         .read_msr = native_read_msr_safe,
984         .write_msr = xen_write_msr_safe,
985         .read_tsc = native_read_tsc,
986         .read_pmc = native_read_pmc,
987
988         .iret = xen_iret,
989         .irq_enable_sysexit = xen_sysexit,
990 #ifdef CONFIG_X86_64
991         .usergs_sysret32 = xen_sysret32,
992         .usergs_sysret64 = xen_sysret64,
993 #endif
994
995         .load_tr_desc = paravirt_nop,
996         .set_ldt = xen_set_ldt,
997         .load_gdt = xen_load_gdt,
998         .load_idt = xen_load_idt,
999         .load_tls = xen_load_tls,
1000 #ifdef CONFIG_X86_64
1001         .load_gs_index = xen_load_gs_index,
1002 #endif
1003
1004         .alloc_ldt = xen_alloc_ldt,
1005         .free_ldt = xen_free_ldt,
1006
1007         .store_gdt = native_store_gdt,
1008         .store_idt = native_store_idt,
1009         .store_tr = xen_store_tr,
1010
1011         .write_ldt_entry = xen_write_ldt_entry,
1012         .write_gdt_entry = xen_write_gdt_entry,
1013         .write_idt_entry = xen_write_idt_entry,
1014         .load_sp0 = xen_load_sp0,
1015
1016         .set_iopl_mask = xen_set_iopl_mask,
1017         .io_delay = xen_io_delay,
1018
1019         /* Xen takes care of %gs when switching to usermode for us */
1020         .swapgs = paravirt_nop,
1021
1022         .start_context_switch = paravirt_start_context_switch,
1023         .end_context_switch = xen_end_context_switch,
1024 };
1025
1026 static const struct pv_apic_ops xen_apic_ops __initconst = {
1027 #ifdef CONFIG_X86_LOCAL_APIC
1028         .startup_ipi_hook = paravirt_nop,
1029 #endif
1030 };
1031
1032 static void xen_reboot(int reason)
1033 {
1034         struct sched_shutdown r = { .reason = reason };
1035
1036         if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
1037                 BUG();
1038 }
1039
1040 static void xen_restart(char *msg)
1041 {
1042         xen_reboot(SHUTDOWN_reboot);
1043 }
1044
1045 static void xen_emergency_restart(void)
1046 {
1047         xen_reboot(SHUTDOWN_reboot);
1048 }
1049
1050 static void xen_machine_halt(void)
1051 {
1052         xen_reboot(SHUTDOWN_poweroff);
1053 }
1054
1055 static void xen_machine_power_off(void)
1056 {
1057         if (pm_power_off)
1058                 pm_power_off();
1059         xen_reboot(SHUTDOWN_poweroff);
1060 }
1061
1062 static void xen_crash_shutdown(struct pt_regs *regs)
1063 {
1064         xen_reboot(SHUTDOWN_crash);
1065 }
1066
1067 static int
1068 xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
1069 {
1070         xen_reboot(SHUTDOWN_crash);
1071         return NOTIFY_DONE;
1072 }
1073
1074 static struct notifier_block xen_panic_block = {
1075         .notifier_call= xen_panic_event,
1076 };
1077
1078 int xen_panic_handler_init(void)
1079 {
1080         atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block);
1081         return 0;
1082 }
1083
1084 static const struct machine_ops xen_machine_ops __initconst = {
1085         .restart = xen_restart,
1086         .halt = xen_machine_halt,
1087         .power_off = xen_machine_power_off,
1088         .shutdown = xen_machine_halt,
1089         .crash_shutdown = xen_crash_shutdown,
1090         .emergency_restart = xen_emergency_restart,
1091 };
1092
1093 /*
1094  * Set up the GDT and segment registers for -fstack-protector.  Until
1095  * we do this, we have to be careful not to call any stack-protected
1096  * function, which is most of the kernel.
1097  */
1098 static void __init xen_setup_stackprotector(void)
1099 {
1100         pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
1101         pv_cpu_ops.load_gdt = xen_load_gdt_boot;
1102
1103         setup_stack_canary_segment(0);
1104         switch_to_new_gdt(0);
1105
1106         pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry;
1107         pv_cpu_ops.load_gdt = xen_load_gdt;
1108 }
1109
1110 /* First C function to be called on Xen boot */
1111 asmlinkage void __init xen_start_kernel(void)
1112 {
1113         struct physdev_set_iopl set_iopl;
1114         int rc;
1115         pgd_t *pgd;
1116
1117         if (!xen_start_info)
1118                 return;
1119
1120         xen_domain_type = XEN_PV_DOMAIN;
1121
1122         xen_setup_machphys_mapping();
1123
1124         /* Install Xen paravirt ops */
1125         pv_info = xen_info;
1126         pv_init_ops = xen_init_ops;
1127         pv_cpu_ops = xen_cpu_ops;
1128         pv_apic_ops = xen_apic_ops;
1129
1130         x86_init.resources.memory_setup = xen_memory_setup;
1131         x86_init.oem.arch_setup = xen_arch_setup;
1132         x86_init.oem.banner = xen_banner;
1133
1134         xen_init_time_ops();
1135
1136         /*
1137          * Set up some pagetable state before starting to set any ptes.
1138          */
1139
1140         xen_init_mmu_ops();
1141
1142         /* Prevent unwanted bits from being set in PTEs. */
1143         __supported_pte_mask &= ~_PAGE_GLOBAL;
1144         if (!xen_initial_domain())
1145                 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
1146
1147         __supported_pte_mask |= _PAGE_IOMAP;
1148
1149         /*
1150          * Prevent page tables from being allocated in highmem, even
1151          * if CONFIG_HIGHPTE is enabled.
1152          */
1153         __userpte_alloc_gfp &= ~__GFP_HIGHMEM;
1154
1155         /* Work out if we support NX */
1156         x86_configure_nx();
1157
1158         xen_setup_features();
1159
1160         /* Get mfn list */
1161         if (!xen_feature(XENFEAT_auto_translated_physmap))
1162                 xen_build_dynamic_phys_to_machine();
1163
1164         /*
1165          * Set up kernel GDT and segment registers, mainly so that
1166          * -fstack-protector code can be executed.
1167          */
1168         xen_setup_stackprotector();
1169
1170         xen_init_irq_ops();
1171         xen_init_cpuid_mask();
1172
1173 #ifdef CONFIG_X86_LOCAL_APIC
1174         /*
1175          * set up the basic apic ops.
1176          */
1177         set_xen_basic_apic_ops();
1178 #endif
1179
1180         if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
1181                 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
1182                 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
1183         }
1184
1185         machine_ops = xen_machine_ops;
1186
1187         /*
1188          * The only reliable way to retain the initial address of the
1189          * percpu gdt_page is to remember it here, so we can go and
1190          * mark it RW later, when the initial percpu area is freed.
1191          */
1192         xen_initial_gdt = &per_cpu(gdt_page, 0);
1193
1194         xen_smp_init();
1195
1196 #ifdef CONFIG_ACPI_NUMA
1197         /*
1198          * The pages we from Xen are not related to machine pages, so
1199          * any NUMA information the kernel tries to get from ACPI will
1200          * be meaningless.  Prevent it from trying.
1201          */
1202         acpi_numa = -1;
1203 #endif
1204
1205         pgd = (pgd_t *)xen_start_info->pt_base;
1206
1207         if (!xen_initial_domain())
1208                 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
1209
1210         __supported_pte_mask |= _PAGE_IOMAP;
1211         /* Don't do the full vcpu_info placement stuff until we have a
1212            possible map and a non-dummy shared_info. */
1213         per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1214
1215         local_irq_disable();
1216         early_boot_irqs_disabled = true;
1217
1218         memblock_init();
1219
1220         xen_raw_console_write("mapping kernel into physical memory\n");
1221         pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages);
1222         xen_ident_map_ISA();
1223
1224         /* Allocate and initialize top and mid mfn levels for p2m structure */
1225         xen_build_mfn_list_list();
1226
1227         /* keep using Xen gdt for now; no urgent need to change it */
1228
1229 #ifdef CONFIG_X86_32
1230         pv_info.kernel_rpl = 1;
1231         if (xen_feature(XENFEAT_supervisor_mode_kernel))
1232                 pv_info.kernel_rpl = 0;
1233 #else
1234         pv_info.kernel_rpl = 0;
1235 #endif
1236         /* set the limit of our address space */
1237         xen_reserve_top();
1238
1239         /* We used to do this in xen_arch_setup, but that is too late on AMD
1240          * were early_cpu_init (run before ->arch_setup()) calls early_amd_init
1241          * which pokes 0xcf8 port.
1242          */
1243         set_iopl.iopl = 1;
1244         rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
1245         if (rc != 0)
1246                 xen_raw_printk("physdev_op failed %d\n", rc);
1247
1248 #ifdef CONFIG_X86_32
1249         /* set up basic CPUID stuff */
1250         cpu_detect(&new_cpu_data);
1251         new_cpu_data.hard_math = 1;
1252         new_cpu_data.wp_works_ok = 1;
1253         new_cpu_data.x86_capability[0] = cpuid_edx(1);
1254 #endif
1255
1256         /* Poke various useful things into boot_params */
1257         boot_params.hdr.type_of_loader = (9 << 4) | 0;
1258         boot_params.hdr.ramdisk_image = xen_start_info->mod_start
1259                 ? __pa(xen_start_info->mod_start) : 0;
1260         boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
1261         boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
1262
1263         if (!xen_initial_domain()) {
1264                 add_preferred_console("xenboot", 0, NULL);
1265                 add_preferred_console("tty", 0, NULL);
1266                 add_preferred_console("hvc", 0, NULL);
1267                 if (pci_xen)
1268                         x86_init.pci.arch_init = pci_xen_init;
1269         } else {
1270                 const struct dom0_vga_console_info *info =
1271                         (void *)((char *)xen_start_info +
1272                                  xen_start_info->console.dom0.info_off);
1273
1274                 xen_init_vga(info, xen_start_info->console.dom0.info_size);
1275                 xen_start_info->console.domU.mfn = 0;
1276                 xen_start_info->console.domU.evtchn = 0;
1277
1278                 /* Make sure ACS will be enabled */
1279                 pci_request_acs();
1280         }
1281                 
1282
1283         xen_raw_console_write("about to get started...\n");
1284
1285         xen_setup_runstate_info(0);
1286
1287         /* Start the world */
1288 #ifdef CONFIG_X86_32
1289         i386_start_kernel();
1290 #else
1291         x86_64_start_reservations((char *)__pa_symbol(&boot_params));
1292 #endif
1293 }
1294
1295 static int init_hvm_pv_info(int *major, int *minor)
1296 {
1297         uint32_t eax, ebx, ecx, edx, pages, msr, base;
1298         u64 pfn;
1299
1300         base = xen_cpuid_base();
1301         cpuid(base + 1, &eax, &ebx, &ecx, &edx);
1302
1303         *major = eax >> 16;
1304         *minor = eax & 0xffff;
1305         printk(KERN_INFO "Xen version %d.%d.\n", *major, *minor);
1306
1307         cpuid(base + 2, &pages, &msr, &ecx, &edx);
1308
1309         pfn = __pa(hypercall_page);
1310         wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
1311
1312         xen_setup_features();
1313
1314         pv_info.name = "Xen HVM";
1315
1316         xen_domain_type = XEN_HVM_DOMAIN;
1317
1318         return 0;
1319 }
1320
1321 void __ref xen_hvm_init_shared_info(void)
1322 {
1323         int cpu;
1324         struct xen_add_to_physmap xatp;
1325         static struct shared_info *shared_info_page = 0;
1326
1327         if (!shared_info_page)
1328                 shared_info_page = (struct shared_info *)
1329                         extend_brk(PAGE_SIZE, PAGE_SIZE);
1330         xatp.domid = DOMID_SELF;
1331         xatp.idx = 0;
1332         xatp.space = XENMAPSPACE_shared_info;
1333         xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
1334         if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
1335                 BUG();
1336
1337         HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
1338
1339         /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
1340          * page, we use it in the event channel upcall and in some pvclock
1341          * related functions. We don't need the vcpu_info placement
1342          * optimizations because we don't use any pv_mmu or pv_irq op on
1343          * HVM.
1344          * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
1345          * online but xen_hvm_init_shared_info is run at resume time too and
1346          * in that case multiple vcpus might be online. */
1347         for_each_online_cpu(cpu) {
1348                 per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
1349         }
1350 }
1351
1352 #ifdef CONFIG_XEN_PVHVM
1353 static int __cpuinit xen_hvm_cpu_notify(struct notifier_block *self,
1354                                     unsigned long action, void *hcpu)
1355 {
1356         int cpu = (long)hcpu;
1357         switch (action) {
1358         case CPU_UP_PREPARE:
1359                 xen_vcpu_setup(cpu);
1360                 if (xen_have_vector_callback)
1361                         xen_init_lock_cpu(cpu);
1362                 break;
1363         default:
1364                 break;
1365         }
1366         return NOTIFY_OK;
1367 }
1368
1369 static struct notifier_block xen_hvm_cpu_notifier __cpuinitdata = {
1370         .notifier_call  = xen_hvm_cpu_notify,
1371 };
1372
1373 static void __init xen_hvm_guest_init(void)
1374 {
1375         int r;
1376         int major, minor;
1377
1378         r = init_hvm_pv_info(&major, &minor);
1379         if (r < 0)
1380                 return;
1381
1382         xen_hvm_init_shared_info();
1383
1384         if (xen_feature(XENFEAT_hvm_callback_vector))
1385                 xen_have_vector_callback = 1;
1386         xen_hvm_smp_init();
1387         register_cpu_notifier(&xen_hvm_cpu_notifier);
1388         xen_unplug_emulated_devices();
1389         x86_init.irqs.intr_init = xen_init_IRQ;
1390         xen_hvm_init_time_ops();
1391         xen_hvm_init_mmu_ops();
1392 }
1393
1394 static bool __init xen_hvm_platform(void)
1395 {
1396         if (xen_pv_domain())
1397                 return false;
1398
1399         if (!xen_cpuid_base())
1400                 return false;
1401
1402         return true;
1403 }
1404
1405 bool xen_hvm_need_lapic(void)
1406 {
1407         if (xen_pv_domain())
1408                 return false;
1409         if (!xen_hvm_domain())
1410                 return false;
1411         if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
1412                 return false;
1413         return true;
1414 }
1415 EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
1416
1417 const struct hypervisor_x86 x86_hyper_xen_hvm __refconst = {
1418         .name                   = "Xen HVM",
1419         .detect                 = xen_hvm_platform,
1420         .init_platform          = xen_hvm_guest_init,
1421 };
1422 EXPORT_SYMBOL(x86_hyper_xen_hvm);
1423 #endif