x86: Move get/set_wallclock to x86_platform_ops
[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/kernel.h>
15 #include <linux/init.h>
16 #include <linux/smp.h>
17 #include <linux/preempt.h>
18 #include <linux/hardirq.h>
19 #include <linux/percpu.h>
20 #include <linux/delay.h>
21 #include <linux/start_kernel.h>
22 #include <linux/sched.h>
23 #include <linux/kprobes.h>
24 #include <linux/bootmem.h>
25 #include <linux/module.h>
26 #include <linux/mm.h>
27 #include <linux/page-flags.h>
28 #include <linux/highmem.h>
29 #include <linux/console.h>
30
31 #include <xen/interface/xen.h>
32 #include <xen/interface/version.h>
33 #include <xen/interface/physdev.h>
34 #include <xen/interface/vcpu.h>
35 #include <xen/features.h>
36 #include <xen/page.h>
37 #include <xen/hvc-console.h>
38
39 #include <asm/paravirt.h>
40 #include <asm/apic.h>
41 #include <asm/page.h>
42 #include <asm/xen/hypercall.h>
43 #include <asm/xen/hypervisor.h>
44 #include <asm/fixmap.h>
45 #include <asm/processor.h>
46 #include <asm/proto.h>
47 #include <asm/msr-index.h>
48 #include <asm/traps.h>
49 #include <asm/setup.h>
50 #include <asm/desc.h>
51 #include <asm/pgtable.h>
52 #include <asm/tlbflush.h>
53 #include <asm/reboot.h>
54
55 #include "xen-ops.h"
56 #include "mmu.h"
57 #include "multicalls.h"
58
59 EXPORT_SYMBOL_GPL(hypercall_page);
60
61 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
62 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
63
64 enum xen_domain_type xen_domain_type = XEN_NATIVE;
65 EXPORT_SYMBOL_GPL(xen_domain_type);
66
67 struct start_info *xen_start_info;
68 EXPORT_SYMBOL_GPL(xen_start_info);
69
70 struct shared_info xen_dummy_shared_info;
71
72 void *xen_initial_gdt;
73
74 /*
75  * Point at some empty memory to start with. We map the real shared_info
76  * page as soon as fixmap is up and running.
77  */
78 struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
79
80 /*
81  * Flag to determine whether vcpu info placement is available on all
82  * VCPUs.  We assume it is to start with, and then set it to zero on
83  * the first failure.  This is because it can succeed on some VCPUs
84  * and not others, since it can involve hypervisor memory allocation,
85  * or because the guest failed to guarantee all the appropriate
86  * constraints on all VCPUs (ie buffer can't cross a page boundary).
87  *
88  * Note that any particular CPU may be using a placed vcpu structure,
89  * but we can only optimise if the all are.
90  *
91  * 0: not available, 1: available
92  */
93 static int have_vcpu_info_placement = 1;
94
95 static void xen_vcpu_setup(int cpu)
96 {
97         struct vcpu_register_vcpu_info info;
98         int err;
99         struct vcpu_info *vcpup;
100
101         BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
102         per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
103
104         if (!have_vcpu_info_placement)
105                 return;         /* already tested, not available */
106
107         vcpup = &per_cpu(xen_vcpu_info, cpu);
108
109         info.mfn = arbitrary_virt_to_mfn(vcpup);
110         info.offset = offset_in_page(vcpup);
111
112         printk(KERN_DEBUG "trying to map vcpu_info %d at %p, mfn %llx, offset %d\n",
113                cpu, vcpup, info.mfn, info.offset);
114
115         /* Check to see if the hypervisor will put the vcpu_info
116            structure where we want it, which allows direct access via
117            a percpu-variable. */
118         err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
119
120         if (err) {
121                 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
122                 have_vcpu_info_placement = 0;
123         } else {
124                 /* This cpu is using the registered vcpu info, even if
125                    later ones fail to. */
126                 per_cpu(xen_vcpu, cpu) = vcpup;
127
128                 printk(KERN_DEBUG "cpu %d using vcpu_info at %p\n",
129                        cpu, vcpup);
130         }
131 }
132
133 /*
134  * On restore, set the vcpu placement up again.
135  * If it fails, then we're in a bad state, since
136  * we can't back out from using it...
137  */
138 void xen_vcpu_restore(void)
139 {
140         if (have_vcpu_info_placement) {
141                 int cpu;
142
143                 for_each_online_cpu(cpu) {
144                         bool other_cpu = (cpu != smp_processor_id());
145
146                         if (other_cpu &&
147                             HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL))
148                                 BUG();
149
150                         xen_vcpu_setup(cpu);
151
152                         if (other_cpu &&
153                             HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
154                                 BUG();
155                 }
156
157                 BUG_ON(!have_vcpu_info_placement);
158         }
159 }
160
161 static void __init xen_banner(void)
162 {
163         unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
164         struct xen_extraversion extra;
165         HYPERVISOR_xen_version(XENVER_extraversion, &extra);
166
167         printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
168                pv_info.name);
169         printk(KERN_INFO "Xen version: %d.%d%s%s\n",
170                version >> 16, version & 0xffff, extra.extraversion,
171                xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
172 }
173
174 static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
175 static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
176
177 static void xen_cpuid(unsigned int *ax, unsigned int *bx,
178                       unsigned int *cx, unsigned int *dx)
179 {
180         unsigned maskecx = ~0;
181         unsigned maskedx = ~0;
182
183         /*
184          * Mask out inconvenient features, to try and disable as many
185          * unsupported kernel subsystems as possible.
186          */
187         if (*ax == 1) {
188                 maskecx = cpuid_leaf1_ecx_mask;
189                 maskedx = cpuid_leaf1_edx_mask;
190         }
191
192         asm(XEN_EMULATE_PREFIX "cpuid"
193                 : "=a" (*ax),
194                   "=b" (*bx),
195                   "=c" (*cx),
196                   "=d" (*dx)
197                 : "0" (*ax), "2" (*cx));
198
199         *cx &= maskecx;
200         *dx &= maskedx;
201 }
202
203 static __init void xen_init_cpuid_mask(void)
204 {
205         unsigned int ax, bx, cx, dx;
206
207         cpuid_leaf1_edx_mask =
208                 ~((1 << X86_FEATURE_MCE)  |  /* disable MCE */
209                   (1 << X86_FEATURE_MCA)  |  /* disable MCA */
210                   (1 << X86_FEATURE_ACC));   /* thermal monitoring */
211
212         if (!xen_initial_domain())
213                 cpuid_leaf1_edx_mask &=
214                         ~((1 << X86_FEATURE_APIC) |  /* disable local APIC */
215                           (1 << X86_FEATURE_ACPI));  /* disable ACPI */
216
217         ax = 1;
218         xen_cpuid(&ax, &bx, &cx, &dx);
219
220         /* cpuid claims we support xsave; try enabling it to see what happens */
221         if (cx & (1 << (X86_FEATURE_XSAVE % 32))) {
222                 unsigned long cr4;
223
224                 set_in_cr4(X86_CR4_OSXSAVE);
225                 
226                 cr4 = read_cr4();
227
228                 if ((cr4 & X86_CR4_OSXSAVE) == 0)
229                         cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_XSAVE % 32));
230
231                 clear_in_cr4(X86_CR4_OSXSAVE);
232         }
233 }
234
235 static void xen_set_debugreg(int reg, unsigned long val)
236 {
237         HYPERVISOR_set_debugreg(reg, val);
238 }
239
240 static unsigned long xen_get_debugreg(int reg)
241 {
242         return HYPERVISOR_get_debugreg(reg);
243 }
244
245 static void xen_end_context_switch(struct task_struct *next)
246 {
247         xen_mc_flush();
248         paravirt_end_context_switch(next);
249 }
250
251 static unsigned long xen_store_tr(void)
252 {
253         return 0;
254 }
255
256 /*
257  * Set the page permissions for a particular virtual address.  If the
258  * address is a vmalloc mapping (or other non-linear mapping), then
259  * find the linear mapping of the page and also set its protections to
260  * match.
261  */
262 static void set_aliased_prot(void *v, pgprot_t prot)
263 {
264         int level;
265         pte_t *ptep;
266         pte_t pte;
267         unsigned long pfn;
268         struct page *page;
269
270         ptep = lookup_address((unsigned long)v, &level);
271         BUG_ON(ptep == NULL);
272
273         pfn = pte_pfn(*ptep);
274         page = pfn_to_page(pfn);
275
276         pte = pfn_pte(pfn, prot);
277
278         if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
279                 BUG();
280
281         if (!PageHighMem(page)) {
282                 void *av = __va(PFN_PHYS(pfn));
283
284                 if (av != v)
285                         if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
286                                 BUG();
287         } else
288                 kmap_flush_unused();
289 }
290
291 static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
292 {
293         const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
294         int i;
295
296         for(i = 0; i < entries; i += entries_per_page)
297                 set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
298 }
299
300 static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
301 {
302         const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
303         int i;
304
305         for(i = 0; i < entries; i += entries_per_page)
306                 set_aliased_prot(ldt + i, PAGE_KERNEL);
307 }
308
309 static void xen_set_ldt(const void *addr, unsigned entries)
310 {
311         struct mmuext_op *op;
312         struct multicall_space mcs = xen_mc_entry(sizeof(*op));
313
314         op = mcs.args;
315         op->cmd = MMUEXT_SET_LDT;
316         op->arg1.linear_addr = (unsigned long)addr;
317         op->arg2.nr_ents = entries;
318
319         MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
320
321         xen_mc_issue(PARAVIRT_LAZY_CPU);
322 }
323
324 static void xen_load_gdt(const struct desc_ptr *dtr)
325 {
326         unsigned long va = dtr->address;
327         unsigned int size = dtr->size + 1;
328         unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
329         unsigned long frames[pages];
330         int f;
331
332         /* A GDT can be up to 64k in size, which corresponds to 8192
333            8-byte entries, or 16 4k pages.. */
334
335         BUG_ON(size > 65536);
336         BUG_ON(va & ~PAGE_MASK);
337
338         for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
339                 int level;
340                 pte_t *ptep = lookup_address(va, &level);
341                 unsigned long pfn, mfn;
342                 void *virt;
343
344                 BUG_ON(ptep == NULL);
345
346                 pfn = pte_pfn(*ptep);
347                 mfn = pfn_to_mfn(pfn);
348                 virt = __va(PFN_PHYS(pfn));
349
350                 frames[f] = mfn;
351
352                 make_lowmem_page_readonly((void *)va);
353                 make_lowmem_page_readonly(virt);
354         }
355
356         if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
357                 BUG();
358 }
359
360 static void load_TLS_descriptor(struct thread_struct *t,
361                                 unsigned int cpu, unsigned int i)
362 {
363         struct desc_struct *gdt = get_cpu_gdt_table(cpu);
364         xmaddr_t maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
365         struct multicall_space mc = __xen_mc_entry(0);
366
367         MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
368 }
369
370 static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
371 {
372         /*
373          * XXX sleazy hack: If we're being called in a lazy-cpu zone
374          * and lazy gs handling is enabled, it means we're in a
375          * context switch, and %gs has just been saved.  This means we
376          * can zero it out to prevent faults on exit from the
377          * hypervisor if the next process has no %gs.  Either way, it
378          * has been saved, and the new value will get loaded properly.
379          * This will go away as soon as Xen has been modified to not
380          * save/restore %gs for normal hypercalls.
381          *
382          * On x86_64, this hack is not used for %gs, because gs points
383          * to KERNEL_GS_BASE (and uses it for PDA references), so we
384          * must not zero %gs on x86_64
385          *
386          * For x86_64, we need to zero %fs, otherwise we may get an
387          * exception between the new %fs descriptor being loaded and
388          * %fs being effectively cleared at __switch_to().
389          */
390         if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
391 #ifdef CONFIG_X86_32
392                 lazy_load_gs(0);
393 #else
394                 loadsegment(fs, 0);
395 #endif
396         }
397
398         xen_mc_batch();
399
400         load_TLS_descriptor(t, cpu, 0);
401         load_TLS_descriptor(t, cpu, 1);
402         load_TLS_descriptor(t, cpu, 2);
403
404         xen_mc_issue(PARAVIRT_LAZY_CPU);
405 }
406
407 #ifdef CONFIG_X86_64
408 static void xen_load_gs_index(unsigned int idx)
409 {
410         if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
411                 BUG();
412 }
413 #endif
414
415 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
416                                 const void *ptr)
417 {
418         xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
419         u64 entry = *(u64 *)ptr;
420
421         preempt_disable();
422
423         xen_mc_flush();
424         if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
425                 BUG();
426
427         preempt_enable();
428 }
429
430 static int cvt_gate_to_trap(int vector, const gate_desc *val,
431                             struct trap_info *info)
432 {
433         unsigned long addr;
434
435         if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT)
436                 return 0;
437
438         info->vector = vector;
439
440         addr = gate_offset(*val);
441 #ifdef CONFIG_X86_64
442         /*
443          * Look for known traps using IST, and substitute them
444          * appropriately.  The debugger ones are the only ones we care
445          * about.  Xen will handle faults like double_fault and
446          * machine_check, so we should never see them.  Warn if
447          * there's an unexpected IST-using fault handler.
448          */
449         if (addr == (unsigned long)debug)
450                 addr = (unsigned long)xen_debug;
451         else if (addr == (unsigned long)int3)
452                 addr = (unsigned long)xen_int3;
453         else if (addr == (unsigned long)stack_segment)
454                 addr = (unsigned long)xen_stack_segment;
455         else if (addr == (unsigned long)double_fault ||
456                  addr == (unsigned long)nmi) {
457                 /* Don't need to handle these */
458                 return 0;
459 #ifdef CONFIG_X86_MCE
460         } else if (addr == (unsigned long)machine_check) {
461                 return 0;
462 #endif
463         } else {
464                 /* Some other trap using IST? */
465                 if (WARN_ON(val->ist != 0))
466                         return 0;
467         }
468 #endif  /* CONFIG_X86_64 */
469         info->address = addr;
470
471         info->cs = gate_segment(*val);
472         info->flags = val->dpl;
473         /* interrupt gates clear IF */
474         if (val->type == GATE_INTERRUPT)
475                 info->flags |= 1 << 2;
476
477         return 1;
478 }
479
480 /* Locations of each CPU's IDT */
481 static DEFINE_PER_CPU(struct desc_ptr, idt_desc);
482
483 /* Set an IDT entry.  If the entry is part of the current IDT, then
484    also update Xen. */
485 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
486 {
487         unsigned long p = (unsigned long)&dt[entrynum];
488         unsigned long start, end;
489
490         preempt_disable();
491
492         start = __get_cpu_var(idt_desc).address;
493         end = start + __get_cpu_var(idt_desc).size + 1;
494
495         xen_mc_flush();
496
497         native_write_idt_entry(dt, entrynum, g);
498
499         if (p >= start && (p + 8) <= end) {
500                 struct trap_info info[2];
501
502                 info[1].address = 0;
503
504                 if (cvt_gate_to_trap(entrynum, g, &info[0]))
505                         if (HYPERVISOR_set_trap_table(info))
506                                 BUG();
507         }
508
509         preempt_enable();
510 }
511
512 static void xen_convert_trap_info(const struct desc_ptr *desc,
513                                   struct trap_info *traps)
514 {
515         unsigned in, out, count;
516
517         count = (desc->size+1) / sizeof(gate_desc);
518         BUG_ON(count > 256);
519
520         for (in = out = 0; in < count; in++) {
521                 gate_desc *entry = (gate_desc*)(desc->address) + in;
522
523                 if (cvt_gate_to_trap(in, entry, &traps[out]))
524                         out++;
525         }
526         traps[out].address = 0;
527 }
528
529 void xen_copy_trap_info(struct trap_info *traps)
530 {
531         const struct desc_ptr *desc = &__get_cpu_var(idt_desc);
532
533         xen_convert_trap_info(desc, traps);
534 }
535
536 /* Load a new IDT into Xen.  In principle this can be per-CPU, so we
537    hold a spinlock to protect the static traps[] array (static because
538    it avoids allocation, and saves stack space). */
539 static void xen_load_idt(const struct desc_ptr *desc)
540 {
541         static DEFINE_SPINLOCK(lock);
542         static struct trap_info traps[257];
543
544         spin_lock(&lock);
545
546         __get_cpu_var(idt_desc) = *desc;
547
548         xen_convert_trap_info(desc, traps);
549
550         xen_mc_flush();
551         if (HYPERVISOR_set_trap_table(traps))
552                 BUG();
553
554         spin_unlock(&lock);
555 }
556
557 /* Write a GDT descriptor entry.  Ignore LDT descriptors, since
558    they're handled differently. */
559 static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
560                                 const void *desc, int type)
561 {
562         preempt_disable();
563
564         switch (type) {
565         case DESC_LDT:
566         case DESC_TSS:
567                 /* ignore */
568                 break;
569
570         default: {
571                 xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]);
572
573                 xen_mc_flush();
574                 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
575                         BUG();
576         }
577
578         }
579
580         preempt_enable();
581 }
582
583 static void xen_load_sp0(struct tss_struct *tss,
584                          struct thread_struct *thread)
585 {
586         struct multicall_space mcs = xen_mc_entry(0);
587         MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
588         xen_mc_issue(PARAVIRT_LAZY_CPU);
589 }
590
591 static void xen_set_iopl_mask(unsigned mask)
592 {
593         struct physdev_set_iopl set_iopl;
594
595         /* Force the change at ring 0. */
596         set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
597         HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
598 }
599
600 static void xen_io_delay(void)
601 {
602 }
603
604 #ifdef CONFIG_X86_LOCAL_APIC
605 static u32 xen_apic_read(u32 reg)
606 {
607         return 0;
608 }
609
610 static void xen_apic_write(u32 reg, u32 val)
611 {
612         /* Warn to see if there's any stray references */
613         WARN_ON(1);
614 }
615
616 static u64 xen_apic_icr_read(void)
617 {
618         return 0;
619 }
620
621 static void xen_apic_icr_write(u32 low, u32 id)
622 {
623         /* Warn to see if there's any stray references */
624         WARN_ON(1);
625 }
626
627 static void xen_apic_wait_icr_idle(void)
628 {
629         return;
630 }
631
632 static u32 xen_safe_apic_wait_icr_idle(void)
633 {
634         return 0;
635 }
636
637 static void set_xen_basic_apic_ops(void)
638 {
639         apic->read = xen_apic_read;
640         apic->write = xen_apic_write;
641         apic->icr_read = xen_apic_icr_read;
642         apic->icr_write = xen_apic_icr_write;
643         apic->wait_icr_idle = xen_apic_wait_icr_idle;
644         apic->safe_wait_icr_idle = xen_safe_apic_wait_icr_idle;
645 }
646
647 #endif
648
649
650 static void xen_clts(void)
651 {
652         struct multicall_space mcs;
653
654         mcs = xen_mc_entry(0);
655
656         MULTI_fpu_taskswitch(mcs.mc, 0);
657
658         xen_mc_issue(PARAVIRT_LAZY_CPU);
659 }
660
661 static DEFINE_PER_CPU(unsigned long, xen_cr0_value);
662
663 static unsigned long xen_read_cr0(void)
664 {
665         unsigned long cr0 = percpu_read(xen_cr0_value);
666
667         if (unlikely(cr0 == 0)) {
668                 cr0 = native_read_cr0();
669                 percpu_write(xen_cr0_value, cr0);
670         }
671
672         return cr0;
673 }
674
675 static void xen_write_cr0(unsigned long cr0)
676 {
677         struct multicall_space mcs;
678
679         percpu_write(xen_cr0_value, cr0);
680
681         /* Only pay attention to cr0.TS; everything else is
682            ignored. */
683         mcs = xen_mc_entry(0);
684
685         MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
686
687         xen_mc_issue(PARAVIRT_LAZY_CPU);
688 }
689
690 static void xen_write_cr4(unsigned long cr4)
691 {
692         cr4 &= ~X86_CR4_PGE;
693         cr4 &= ~X86_CR4_PSE;
694
695         native_write_cr4(cr4);
696 }
697
698 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
699 {
700         int ret;
701
702         ret = 0;
703
704         switch (msr) {
705 #ifdef CONFIG_X86_64
706                 unsigned which;
707                 u64 base;
708
709         case MSR_FS_BASE:               which = SEGBASE_FS; goto set;
710         case MSR_KERNEL_GS_BASE:        which = SEGBASE_GS_USER; goto set;
711         case MSR_GS_BASE:               which = SEGBASE_GS_KERNEL; goto set;
712
713         set:
714                 base = ((u64)high << 32) | low;
715                 if (HYPERVISOR_set_segment_base(which, base) != 0)
716                         ret = -EFAULT;
717                 break;
718 #endif
719
720         case MSR_STAR:
721         case MSR_CSTAR:
722         case MSR_LSTAR:
723         case MSR_SYSCALL_MASK:
724         case MSR_IA32_SYSENTER_CS:
725         case MSR_IA32_SYSENTER_ESP:
726         case MSR_IA32_SYSENTER_EIP:
727                 /* Fast syscall setup is all done in hypercalls, so
728                    these are all ignored.  Stub them out here to stop
729                    Xen console noise. */
730                 break;
731
732         default:
733                 ret = native_write_msr_safe(msr, low, high);
734         }
735
736         return ret;
737 }
738
739 void xen_setup_shared_info(void)
740 {
741         if (!xen_feature(XENFEAT_auto_translated_physmap)) {
742                 set_fixmap(FIX_PARAVIRT_BOOTMAP,
743                            xen_start_info->shared_info);
744
745                 HYPERVISOR_shared_info =
746                         (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
747         } else
748                 HYPERVISOR_shared_info =
749                         (struct shared_info *)__va(xen_start_info->shared_info);
750
751 #ifndef CONFIG_SMP
752         /* In UP this is as good a place as any to set up shared info */
753         xen_setup_vcpu_info_placement();
754 #endif
755
756         xen_setup_mfn_list_list();
757 }
758
759 /* This is called once we have the cpu_possible_map */
760 void xen_setup_vcpu_info_placement(void)
761 {
762         int cpu;
763
764         for_each_possible_cpu(cpu)
765                 xen_vcpu_setup(cpu);
766
767         /* xen_vcpu_setup managed to place the vcpu_info within the
768            percpu area for all cpus, so make use of it */
769         if (have_vcpu_info_placement) {
770                 printk(KERN_INFO "Xen: using vcpu_info placement\n");
771
772                 pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
773                 pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct);
774                 pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
775                 pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
776                 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
777         }
778 }
779
780 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
781                           unsigned long addr, unsigned len)
782 {
783         char *start, *end, *reloc;
784         unsigned ret;
785
786         start = end = reloc = NULL;
787
788 #define SITE(op, x)                                                     \
789         case PARAVIRT_PATCH(op.x):                                      \
790         if (have_vcpu_info_placement) {                                 \
791                 start = (char *)xen_##x##_direct;                       \
792                 end = xen_##x##_direct_end;                             \
793                 reloc = xen_##x##_direct_reloc;                         \
794         }                                                               \
795         goto patch_site
796
797         switch (type) {
798                 SITE(pv_irq_ops, irq_enable);
799                 SITE(pv_irq_ops, irq_disable);
800                 SITE(pv_irq_ops, save_fl);
801                 SITE(pv_irq_ops, restore_fl);
802 #undef SITE
803
804         patch_site:
805                 if (start == NULL || (end-start) > len)
806                         goto default_patch;
807
808                 ret = paravirt_patch_insns(insnbuf, len, start, end);
809
810                 /* Note: because reloc is assigned from something that
811                    appears to be an array, gcc assumes it's non-null,
812                    but doesn't know its relationship with start and
813                    end. */
814                 if (reloc > start && reloc < end) {
815                         int reloc_off = reloc - start;
816                         long *relocp = (long *)(insnbuf + reloc_off);
817                         long delta = start - (char *)addr;
818
819                         *relocp += delta;
820                 }
821                 break;
822
823         default_patch:
824         default:
825                 ret = paravirt_patch_default(type, clobbers, insnbuf,
826                                              addr, len);
827                 break;
828         }
829
830         return ret;
831 }
832
833 static const struct pv_info xen_info __initdata = {
834         .paravirt_enabled = 1,
835         .shared_kernel_pmd = 0,
836
837         .name = "Xen",
838 };
839
840 static const struct pv_init_ops xen_init_ops __initdata = {
841         .patch = xen_patch,
842 };
843
844 static const struct pv_time_ops xen_time_ops __initdata = {
845         .sched_clock = xen_sched_clock,
846 };
847
848 static const struct pv_cpu_ops xen_cpu_ops __initdata = {
849         .cpuid = xen_cpuid,
850
851         .set_debugreg = xen_set_debugreg,
852         .get_debugreg = xen_get_debugreg,
853
854         .clts = xen_clts,
855
856         .read_cr0 = xen_read_cr0,
857         .write_cr0 = xen_write_cr0,
858
859         .read_cr4 = native_read_cr4,
860         .read_cr4_safe = native_read_cr4_safe,
861         .write_cr4 = xen_write_cr4,
862
863         .wbinvd = native_wbinvd,
864
865         .read_msr = native_read_msr_safe,
866         .write_msr = xen_write_msr_safe,
867         .read_tsc = native_read_tsc,
868         .read_pmc = native_read_pmc,
869
870         .iret = xen_iret,
871         .irq_enable_sysexit = xen_sysexit,
872 #ifdef CONFIG_X86_64
873         .usergs_sysret32 = xen_sysret32,
874         .usergs_sysret64 = xen_sysret64,
875 #endif
876
877         .load_tr_desc = paravirt_nop,
878         .set_ldt = xen_set_ldt,
879         .load_gdt = xen_load_gdt,
880         .load_idt = xen_load_idt,
881         .load_tls = xen_load_tls,
882 #ifdef CONFIG_X86_64
883         .load_gs_index = xen_load_gs_index,
884 #endif
885
886         .alloc_ldt = xen_alloc_ldt,
887         .free_ldt = xen_free_ldt,
888
889         .store_gdt = native_store_gdt,
890         .store_idt = native_store_idt,
891         .store_tr = xen_store_tr,
892
893         .write_ldt_entry = xen_write_ldt_entry,
894         .write_gdt_entry = xen_write_gdt_entry,
895         .write_idt_entry = xen_write_idt_entry,
896         .load_sp0 = xen_load_sp0,
897
898         .set_iopl_mask = xen_set_iopl_mask,
899         .io_delay = xen_io_delay,
900
901         /* Xen takes care of %gs when switching to usermode for us */
902         .swapgs = paravirt_nop,
903
904         .start_context_switch = paravirt_start_context_switch,
905         .end_context_switch = xen_end_context_switch,
906 };
907
908 static const struct pv_apic_ops xen_apic_ops __initdata = {
909 #ifdef CONFIG_X86_LOCAL_APIC
910         .startup_ipi_hook = paravirt_nop,
911 #endif
912 };
913
914 static void xen_reboot(int reason)
915 {
916         struct sched_shutdown r = { .reason = reason };
917
918 #ifdef CONFIG_SMP
919         smp_send_stop();
920 #endif
921
922         if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
923                 BUG();
924 }
925
926 static void xen_restart(char *msg)
927 {
928         xen_reboot(SHUTDOWN_reboot);
929 }
930
931 static void xen_emergency_restart(void)
932 {
933         xen_reboot(SHUTDOWN_reboot);
934 }
935
936 static void xen_machine_halt(void)
937 {
938         xen_reboot(SHUTDOWN_poweroff);
939 }
940
941 static void xen_crash_shutdown(struct pt_regs *regs)
942 {
943         xen_reboot(SHUTDOWN_crash);
944 }
945
946 static const struct machine_ops __initdata xen_machine_ops = {
947         .restart = xen_restart,
948         .halt = xen_machine_halt,
949         .power_off = xen_machine_halt,
950         .shutdown = xen_machine_halt,
951         .crash_shutdown = xen_crash_shutdown,
952         .emergency_restart = xen_emergency_restart,
953 };
954
955 /* First C function to be called on Xen boot */
956 asmlinkage void __init xen_start_kernel(void)
957 {
958         pgd_t *pgd;
959
960         if (!xen_start_info)
961                 return;
962
963         xen_domain_type = XEN_PV_DOMAIN;
964
965         /* Install Xen paravirt ops */
966         pv_info = xen_info;
967         pv_init_ops = xen_init_ops;
968         pv_time_ops = xen_time_ops;
969         pv_cpu_ops = xen_cpu_ops;
970         pv_apic_ops = xen_apic_ops;
971
972         x86_init.resources.memory_setup = xen_memory_setup;
973         x86_init.oem.arch_setup = xen_arch_setup;
974         x86_init.oem.banner = xen_banner;
975
976         x86_init.timers.timer_init = xen_time_init;
977         x86_init.timers.setup_percpu_clockev = x86_init_noop;
978         x86_cpuinit.setup_percpu_clockev = x86_init_noop;
979
980         x86_platform.calibrate_tsc = xen_tsc_khz;
981         x86_platform.get_wallclock = xen_get_wallclock;
982         x86_platform.set_wallclock = xen_set_wallclock;
983
984 #ifdef CONFIG_X86_64
985         /*
986          * Setup percpu state.  We only need to do this for 64-bit
987          * because 32-bit already has %fs set properly.
988          */
989         load_percpu_segment(0);
990 #endif
991
992         xen_init_mmu_ops();
993         xen_init_irq_ops();
994         xen_init_cpuid_mask();
995
996 #ifdef CONFIG_X86_LOCAL_APIC
997         /*
998          * set up the basic apic ops.
999          */
1000         set_xen_basic_apic_ops();
1001 #endif
1002
1003         xen_setup_features();
1004
1005         if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
1006                 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
1007                 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
1008         }
1009
1010         machine_ops = xen_machine_ops;
1011
1012         /*
1013          * The only reliable way to retain the initial address of the
1014          * percpu gdt_page is to remember it here, so we can go and
1015          * mark it RW later, when the initial percpu area is freed.
1016          */
1017         xen_initial_gdt = &per_cpu(gdt_page, 0);
1018
1019         xen_smp_init();
1020
1021         /* Get mfn list */
1022         if (!xen_feature(XENFEAT_auto_translated_physmap))
1023                 xen_build_dynamic_phys_to_machine();
1024
1025         pgd = (pgd_t *)xen_start_info->pt_base;
1026
1027         /* Prevent unwanted bits from being set in PTEs. */
1028         __supported_pte_mask &= ~_PAGE_GLOBAL;
1029         if (!xen_initial_domain())
1030                 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
1031
1032 #ifdef CONFIG_X86_64
1033         /* Work out if we support NX */
1034         check_efer();
1035 #endif
1036
1037         /* Don't do the full vcpu_info placement stuff until we have a
1038            possible map and a non-dummy shared_info. */
1039         per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1040
1041         local_irq_disable();
1042         early_boot_irqs_off();
1043
1044         xen_raw_console_write("mapping kernel into physical memory\n");
1045         pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages);
1046
1047         init_mm.pgd = pgd;
1048
1049         /* keep using Xen gdt for now; no urgent need to change it */
1050
1051         pv_info.kernel_rpl = 1;
1052         if (xen_feature(XENFEAT_supervisor_mode_kernel))
1053                 pv_info.kernel_rpl = 0;
1054
1055         /* set the limit of our address space */
1056         xen_reserve_top();
1057
1058 #ifdef CONFIG_X86_32
1059         /* set up basic CPUID stuff */
1060         cpu_detect(&new_cpu_data);
1061         new_cpu_data.hard_math = 1;
1062         new_cpu_data.x86_capability[0] = cpuid_edx(1);
1063 #endif
1064
1065         /* Poke various useful things into boot_params */
1066         boot_params.hdr.type_of_loader = (9 << 4) | 0;
1067         boot_params.hdr.ramdisk_image = xen_start_info->mod_start
1068                 ? __pa(xen_start_info->mod_start) : 0;
1069         boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
1070         boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
1071
1072         if (!xen_initial_domain()) {
1073                 add_preferred_console("xenboot", 0, NULL);
1074                 add_preferred_console("tty", 0, NULL);
1075                 add_preferred_console("hvc", 0, NULL);
1076         }
1077
1078         xen_raw_console_write("about to get started...\n");
1079
1080         /* Start the world */
1081 #ifdef CONFIG_X86_32
1082         i386_start_kernel();
1083 #else
1084         x86_64_start_reservations((char *)__pa_symbol(&boot_params));
1085 #endif
1086 }