0013a729b41ddc93045510068da9bcbbadf76433
[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/bootmem.h>
24 #include <linux/module.h>
25 #include <linux/mm.h>
26 #include <linux/page-flags.h>
27 #include <linux/highmem.h>
28 #include <linux/console.h>
29
30 #include <xen/interface/xen.h>
31 #include <xen/interface/physdev.h>
32 #include <xen/interface/vcpu.h>
33 #include <xen/features.h>
34 #include <xen/page.h>
35 #include <xen/hvc-console.h>
36
37 #include <asm/paravirt.h>
38 #include <asm/apic.h>
39 #include <asm/page.h>
40 #include <asm/xen/hypercall.h>
41 #include <asm/xen/hypervisor.h>
42 #include <asm/fixmap.h>
43 #include <asm/processor.h>
44 #include <asm/msr-index.h>
45 #include <asm/setup.h>
46 #include <asm/desc.h>
47 #include <asm/pgtable.h>
48 #include <asm/tlbflush.h>
49 #include <asm/reboot.h>
50
51 #include "xen-ops.h"
52 #include "mmu.h"
53 #include "multicalls.h"
54
55 EXPORT_SYMBOL_GPL(hypercall_page);
56
57 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
58 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
59
60 enum xen_domain_type xen_domain_type = XEN_NATIVE;
61 EXPORT_SYMBOL_GPL(xen_domain_type);
62
63 /*
64  * Identity map, in addition to plain kernel map.  This needs to be
65  * large enough to allocate page table pages to allocate the rest.
66  * Each page can map 2MB.
67  */
68 static pte_t level1_ident_pgt[PTRS_PER_PTE * 4] __page_aligned_bss;
69
70 #ifdef CONFIG_X86_64
71 /* l3 pud for userspace vsyscall mapping */
72 static pud_t level3_user_vsyscall[PTRS_PER_PUD] __page_aligned_bss;
73 #endif /* CONFIG_X86_64 */
74
75 /*
76  * Note about cr3 (pagetable base) values:
77  *
78  * xen_cr3 contains the current logical cr3 value; it contains the
79  * last set cr3.  This may not be the current effective cr3, because
80  * its update may be being lazily deferred.  However, a vcpu looking
81  * at its own cr3 can use this value knowing that it everything will
82  * be self-consistent.
83  *
84  * xen_current_cr3 contains the actual vcpu cr3; it is set once the
85  * hypercall to set the vcpu cr3 is complete (so it may be a little
86  * out of date, but it will never be set early).  If one vcpu is
87  * looking at another vcpu's cr3 value, it should use this variable.
88  */
89 DEFINE_PER_CPU(unsigned long, xen_cr3);  /* cr3 stored as physaddr */
90 DEFINE_PER_CPU(unsigned long, xen_current_cr3);  /* actual vcpu cr3 */
91
92 struct start_info *xen_start_info;
93 EXPORT_SYMBOL_GPL(xen_start_info);
94
95 struct shared_info xen_dummy_shared_info;
96
97 /*
98  * Point at some empty memory to start with. We map the real shared_info
99  * page as soon as fixmap is up and running.
100  */
101 struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
102
103 /*
104  * Flag to determine whether vcpu info placement is available on all
105  * VCPUs.  We assume it is to start with, and then set it to zero on
106  * the first failure.  This is because it can succeed on some VCPUs
107  * and not others, since it can involve hypervisor memory allocation,
108  * or because the guest failed to guarantee all the appropriate
109  * constraints on all VCPUs (ie buffer can't cross a page boundary).
110  *
111  * Note that any particular CPU may be using a placed vcpu structure,
112  * but we can only optimise if the all are.
113  *
114  * 0: not available, 1: available
115  */
116 static int have_vcpu_info_placement =
117 #ifdef CONFIG_X86_32
118         1
119 #else
120         0
121 #endif
122         ;
123
124
125 static void xen_vcpu_setup(int cpu)
126 {
127         struct vcpu_register_vcpu_info info;
128         int err;
129         struct vcpu_info *vcpup;
130
131         BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
132         per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
133
134         if (!have_vcpu_info_placement)
135                 return;         /* already tested, not available */
136
137         vcpup = &per_cpu(xen_vcpu_info, cpu);
138
139         info.mfn = virt_to_mfn(vcpup);
140         info.offset = offset_in_page(vcpup);
141
142         printk(KERN_DEBUG "trying to map vcpu_info %d at %p, mfn %llx, offset %d\n",
143                cpu, vcpup, info.mfn, info.offset);
144
145         /* Check to see if the hypervisor will put the vcpu_info
146            structure where we want it, which allows direct access via
147            a percpu-variable. */
148         err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
149
150         if (err) {
151                 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
152                 have_vcpu_info_placement = 0;
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                 printk(KERN_DEBUG "cpu %d using vcpu_info at %p\n",
159                        cpu, vcpup);
160         }
161 }
162
163 /*
164  * On restore, set the vcpu placement up again.
165  * If it fails, then we're in a bad state, since
166  * we can't back out from using it...
167  */
168 void xen_vcpu_restore(void)
169 {
170         if (have_vcpu_info_placement) {
171                 int cpu;
172
173                 for_each_online_cpu(cpu) {
174                         bool other_cpu = (cpu != smp_processor_id());
175
176                         if (other_cpu &&
177                             HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL))
178                                 BUG();
179
180                         xen_vcpu_setup(cpu);
181
182                         if (other_cpu &&
183                             HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
184                                 BUG();
185                 }
186
187                 BUG_ON(!have_vcpu_info_placement);
188         }
189 }
190
191 static void __init xen_banner(void)
192 {
193         unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
194         struct xen_extraversion extra;
195         HYPERVISOR_xen_version(XENVER_extraversion, &extra);
196
197         printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
198                pv_info.name);
199         printk(KERN_INFO "Xen version: %d.%d%s%s\n",
200                version >> 16, version & 0xffff, extra.extraversion,
201                xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
202 }
203
204 static void xen_cpuid(unsigned int *ax, unsigned int *bx,
205                       unsigned int *cx, unsigned int *dx)
206 {
207         unsigned maskedx = ~0;
208
209         /*
210          * Mask out inconvenient features, to try and disable as many
211          * unsupported kernel subsystems as possible.
212          */
213         if (*ax == 1)
214                 maskedx = ~((1 << X86_FEATURE_APIC) |  /* disable APIC */
215                             (1 << X86_FEATURE_ACPI) |  /* disable ACPI */
216                             (1 << X86_FEATURE_MCE)  |  /* disable MCE */
217                             (1 << X86_FEATURE_MCA)  |  /* disable MCA */
218                             (1 << X86_FEATURE_ACC));   /* thermal monitoring */
219
220         asm(XEN_EMULATE_PREFIX "cpuid"
221                 : "=a" (*ax),
222                   "=b" (*bx),
223                   "=c" (*cx),
224                   "=d" (*dx)
225                 : "0" (*ax), "2" (*cx));
226         *dx &= maskedx;
227 }
228
229 static void xen_set_debugreg(int reg, unsigned long val)
230 {
231         HYPERVISOR_set_debugreg(reg, val);
232 }
233
234 static unsigned long xen_get_debugreg(int reg)
235 {
236         return HYPERVISOR_get_debugreg(reg);
237 }
238
239 static void xen_leave_lazy(void)
240 {
241         paravirt_leave_lazy(paravirt_get_lazy_mode());
242         xen_mc_flush();
243 }
244
245 static unsigned long xen_store_tr(void)
246 {
247         return 0;
248 }
249
250 /*
251  * Set the page permissions for a particular virtual address.  If the
252  * address is a vmalloc mapping (or other non-linear mapping), then
253  * find the linear mapping of the page and also set its protections to
254  * match.
255  */
256 static void set_aliased_prot(void *v, pgprot_t prot)
257 {
258         int level;
259         pte_t *ptep;
260         pte_t pte;
261         unsigned long pfn;
262         struct page *page;
263
264         ptep = lookup_address((unsigned long)v, &level);
265         BUG_ON(ptep == NULL);
266
267         pfn = pte_pfn(*ptep);
268         page = pfn_to_page(pfn);
269
270         pte = pfn_pte(pfn, prot);
271
272         if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
273                 BUG();
274
275         if (!PageHighMem(page)) {
276                 void *av = __va(PFN_PHYS(pfn));
277
278                 if (av != v)
279                         if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
280                                 BUG();
281         } else
282                 kmap_flush_unused();
283 }
284
285 static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
286 {
287         const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
288         int i;
289
290         for(i = 0; i < entries; i += entries_per_page)
291                 set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
292 }
293
294 static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
295 {
296         const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
297         int i;
298
299         for(i = 0; i < entries; i += entries_per_page)
300                 set_aliased_prot(ldt + i, PAGE_KERNEL);
301 }
302
303 static void xen_set_ldt(const void *addr, unsigned entries)
304 {
305         struct mmuext_op *op;
306         struct multicall_space mcs = xen_mc_entry(sizeof(*op));
307
308         op = mcs.args;
309         op->cmd = MMUEXT_SET_LDT;
310         op->arg1.linear_addr = (unsigned long)addr;
311         op->arg2.nr_ents = entries;
312
313         MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
314
315         xen_mc_issue(PARAVIRT_LAZY_CPU);
316 }
317
318 static void xen_load_gdt(const struct desc_ptr *dtr)
319 {
320         unsigned long *frames;
321         unsigned long va = dtr->address;
322         unsigned int size = dtr->size + 1;
323         unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
324         int f;
325         struct multicall_space mcs;
326
327         /* A GDT can be up to 64k in size, which corresponds to 8192
328            8-byte entries, or 16 4k pages.. */
329
330         BUG_ON(size > 65536);
331         BUG_ON(va & ~PAGE_MASK);
332
333         mcs = xen_mc_entry(sizeof(*frames) * pages);
334         frames = mcs.args;
335
336         for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
337                 frames[f] = virt_to_mfn(va);
338                 make_lowmem_page_readonly((void *)va);
339         }
340
341         MULTI_set_gdt(mcs.mc, frames, size / sizeof(struct desc_struct));
342
343         xen_mc_issue(PARAVIRT_LAZY_CPU);
344 }
345
346 static void load_TLS_descriptor(struct thread_struct *t,
347                                 unsigned int cpu, unsigned int i)
348 {
349         struct desc_struct *gdt = get_cpu_gdt_table(cpu);
350         xmaddr_t maddr = virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
351         struct multicall_space mc = __xen_mc_entry(0);
352
353         MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
354 }
355
356 static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
357 {
358         /*
359          * XXX sleazy hack: If we're being called in a lazy-cpu zone,
360          * it means we're in a context switch, and %gs has just been
361          * saved.  This means we can zero it out to prevent faults on
362          * exit from the hypervisor if the next process has no %gs.
363          * Either way, it has been saved, and the new value will get
364          * loaded properly.  This will go away as soon as Xen has been
365          * modified to not save/restore %gs for normal hypercalls.
366          *
367          * On x86_64, this hack is not used for %gs, because gs points
368          * to KERNEL_GS_BASE (and uses it for PDA references), so we
369          * must not zero %gs on x86_64
370          *
371          * For x86_64, we need to zero %fs, otherwise we may get an
372          * exception between the new %fs descriptor being loaded and
373          * %fs being effectively cleared at __switch_to().
374          */
375         if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
376 #ifdef CONFIG_X86_32
377                 loadsegment(gs, 0);
378 #else
379                 loadsegment(fs, 0);
380 #endif
381         }
382
383         xen_mc_batch();
384
385         load_TLS_descriptor(t, cpu, 0);
386         load_TLS_descriptor(t, cpu, 1);
387         load_TLS_descriptor(t, cpu, 2);
388
389         xen_mc_issue(PARAVIRT_LAZY_CPU);
390 }
391
392 #ifdef CONFIG_X86_64
393 static void xen_load_gs_index(unsigned int idx)
394 {
395         if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
396                 BUG();
397 }
398 #endif
399
400 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
401                                 const void *ptr)
402 {
403         xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
404         u64 entry = *(u64 *)ptr;
405
406         preempt_disable();
407
408         xen_mc_flush();
409         if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
410                 BUG();
411
412         preempt_enable();
413 }
414
415 static int cvt_gate_to_trap(int vector, const gate_desc *val,
416                             struct trap_info *info)
417 {
418         if (val->type != 0xf && val->type != 0xe)
419                 return 0;
420
421         info->vector = vector;
422         info->address = gate_offset(*val);
423         info->cs = gate_segment(*val);
424         info->flags = val->dpl;
425         /* interrupt gates clear IF */
426         if (val->type == 0xe)
427                 info->flags |= 4;
428
429         return 1;
430 }
431
432 /* Locations of each CPU's IDT */
433 static DEFINE_PER_CPU(struct desc_ptr, idt_desc);
434
435 /* Set an IDT entry.  If the entry is part of the current IDT, then
436    also update Xen. */
437 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
438 {
439         unsigned long p = (unsigned long)&dt[entrynum];
440         unsigned long start, end;
441
442         preempt_disable();
443
444         start = __get_cpu_var(idt_desc).address;
445         end = start + __get_cpu_var(idt_desc).size + 1;
446
447         xen_mc_flush();
448
449         native_write_idt_entry(dt, entrynum, g);
450
451         if (p >= start && (p + 8) <= end) {
452                 struct trap_info info[2];
453
454                 info[1].address = 0;
455
456                 if (cvt_gate_to_trap(entrynum, g, &info[0]))
457                         if (HYPERVISOR_set_trap_table(info))
458                                 BUG();
459         }
460
461         preempt_enable();
462 }
463
464 static void xen_convert_trap_info(const struct desc_ptr *desc,
465                                   struct trap_info *traps)
466 {
467         unsigned in, out, count;
468
469         count = (desc->size+1) / sizeof(gate_desc);
470         BUG_ON(count > 256);
471
472         for (in = out = 0; in < count; in++) {
473                 gate_desc *entry = (gate_desc*)(desc->address) + in;
474
475                 if (cvt_gate_to_trap(in, entry, &traps[out]))
476                         out++;
477         }
478         traps[out].address = 0;
479 }
480
481 void xen_copy_trap_info(struct trap_info *traps)
482 {
483         const struct desc_ptr *desc = &__get_cpu_var(idt_desc);
484
485         xen_convert_trap_info(desc, traps);
486 }
487
488 /* Load a new IDT into Xen.  In principle this can be per-CPU, so we
489    hold a spinlock to protect the static traps[] array (static because
490    it avoids allocation, and saves stack space). */
491 static void xen_load_idt(const struct desc_ptr *desc)
492 {
493         static DEFINE_SPINLOCK(lock);
494         static struct trap_info traps[257];
495
496         spin_lock(&lock);
497
498         __get_cpu_var(idt_desc) = *desc;
499
500         xen_convert_trap_info(desc, traps);
501
502         xen_mc_flush();
503         if (HYPERVISOR_set_trap_table(traps))
504                 BUG();
505
506         spin_unlock(&lock);
507 }
508
509 /* Write a GDT descriptor entry.  Ignore LDT descriptors, since
510    they're handled differently. */
511 static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
512                                 const void *desc, int type)
513 {
514         preempt_disable();
515
516         switch (type) {
517         case DESC_LDT:
518         case DESC_TSS:
519                 /* ignore */
520                 break;
521
522         default: {
523                 xmaddr_t maddr = virt_to_machine(&dt[entry]);
524
525                 xen_mc_flush();
526                 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
527                         BUG();
528         }
529
530         }
531
532         preempt_enable();
533 }
534
535 static void xen_load_sp0(struct tss_struct *tss,
536                          struct thread_struct *thread)
537 {
538         struct multicall_space mcs = xen_mc_entry(0);
539         MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
540         xen_mc_issue(PARAVIRT_LAZY_CPU);
541 }
542
543 static void xen_set_iopl_mask(unsigned mask)
544 {
545         struct physdev_set_iopl set_iopl;
546
547         /* Force the change at ring 0. */
548         set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
549         HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
550 }
551
552 static void xen_io_delay(void)
553 {
554 }
555
556 #ifdef CONFIG_X86_LOCAL_APIC
557 static u32 xen_apic_read(u32 reg)
558 {
559         return 0;
560 }
561
562 static void xen_apic_write(u32 reg, u32 val)
563 {
564         /* Warn to see if there's any stray references */
565         WARN_ON(1);
566 }
567
568 static u64 xen_apic_icr_read(void)
569 {
570         return 0;
571 }
572
573 static void xen_apic_icr_write(u32 low, u32 id)
574 {
575         /* Warn to see if there's any stray references */
576         WARN_ON(1);
577 }
578
579 static void xen_apic_wait_icr_idle(void)
580 {
581         return;
582 }
583
584 static u32 xen_safe_apic_wait_icr_idle(void)
585 {
586         return 0;
587 }
588
589 static struct apic_ops xen_basic_apic_ops = {
590         .read = xen_apic_read,
591         .write = xen_apic_write,
592         .icr_read = xen_apic_icr_read,
593         .icr_write = xen_apic_icr_write,
594         .wait_icr_idle = xen_apic_wait_icr_idle,
595         .safe_wait_icr_idle = xen_safe_apic_wait_icr_idle,
596 };
597
598 #endif
599
600 static void xen_flush_tlb(void)
601 {
602         struct mmuext_op *op;
603         struct multicall_space mcs;
604
605         preempt_disable();
606
607         mcs = xen_mc_entry(sizeof(*op));
608
609         op = mcs.args;
610         op->cmd = MMUEXT_TLB_FLUSH_LOCAL;
611         MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
612
613         xen_mc_issue(PARAVIRT_LAZY_MMU);
614
615         preempt_enable();
616 }
617
618 static void xen_flush_tlb_single(unsigned long addr)
619 {
620         struct mmuext_op *op;
621         struct multicall_space mcs;
622
623         preempt_disable();
624
625         mcs = xen_mc_entry(sizeof(*op));
626         op = mcs.args;
627         op->cmd = MMUEXT_INVLPG_LOCAL;
628         op->arg1.linear_addr = addr & PAGE_MASK;
629         MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
630
631         xen_mc_issue(PARAVIRT_LAZY_MMU);
632
633         preempt_enable();
634 }
635
636 static void xen_flush_tlb_others(const cpumask_t *cpus, struct mm_struct *mm,
637                                  unsigned long va)
638 {
639         struct {
640                 struct mmuext_op op;
641                 cpumask_t mask;
642         } *args;
643         cpumask_t cpumask = *cpus;
644         struct multicall_space mcs;
645
646         /*
647          * A couple of (to be removed) sanity checks:
648          *
649          * - current CPU must not be in mask
650          * - mask must exist :)
651          */
652         BUG_ON(cpus_empty(cpumask));
653         BUG_ON(cpu_isset(smp_processor_id(), cpumask));
654         BUG_ON(!mm);
655
656         /* If a CPU which we ran on has gone down, OK. */
657         cpus_and(cpumask, cpumask, cpu_online_map);
658         if (cpus_empty(cpumask))
659                 return;
660
661         mcs = xen_mc_entry(sizeof(*args));
662         args = mcs.args;
663         args->mask = cpumask;
664         args->op.arg2.vcpumask = &args->mask;
665
666         if (va == TLB_FLUSH_ALL) {
667                 args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
668         } else {
669                 args->op.cmd = MMUEXT_INVLPG_MULTI;
670                 args->op.arg1.linear_addr = va;
671         }
672
673         MULTI_mmuext_op(mcs.mc, &args->op, 1, NULL, DOMID_SELF);
674
675         xen_mc_issue(PARAVIRT_LAZY_MMU);
676 }
677
678 static void xen_clts(void)
679 {
680         struct multicall_space mcs;
681
682         mcs = xen_mc_entry(0);
683
684         MULTI_fpu_taskswitch(mcs.mc, 0);
685
686         xen_mc_issue(PARAVIRT_LAZY_CPU);
687 }
688
689 static void xen_write_cr0(unsigned long cr0)
690 {
691         struct multicall_space mcs;
692
693         /* Only pay attention to cr0.TS; everything else is
694            ignored. */
695         mcs = xen_mc_entry(0);
696
697         MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
698
699         xen_mc_issue(PARAVIRT_LAZY_CPU);
700 }
701
702 static void xen_write_cr2(unsigned long cr2)
703 {
704         x86_read_percpu(xen_vcpu)->arch.cr2 = cr2;
705 }
706
707 static unsigned long xen_read_cr2(void)
708 {
709         return x86_read_percpu(xen_vcpu)->arch.cr2;
710 }
711
712 static unsigned long xen_read_cr2_direct(void)
713 {
714         return x86_read_percpu(xen_vcpu_info.arch.cr2);
715 }
716
717 static void xen_write_cr4(unsigned long cr4)
718 {
719         cr4 &= ~X86_CR4_PGE;
720         cr4 &= ~X86_CR4_PSE;
721
722         native_write_cr4(cr4);
723 }
724
725 static unsigned long xen_read_cr3(void)
726 {
727         return x86_read_percpu(xen_cr3);
728 }
729
730 static void set_current_cr3(void *v)
731 {
732         x86_write_percpu(xen_current_cr3, (unsigned long)v);
733 }
734
735 static void __xen_write_cr3(bool kernel, unsigned long cr3)
736 {
737         struct mmuext_op *op;
738         struct multicall_space mcs;
739         unsigned long mfn;
740
741         if (cr3)
742                 mfn = pfn_to_mfn(PFN_DOWN(cr3));
743         else
744                 mfn = 0;
745
746         WARN_ON(mfn == 0 && kernel);
747
748         mcs = __xen_mc_entry(sizeof(*op));
749
750         op = mcs.args;
751         op->cmd = kernel ? MMUEXT_NEW_BASEPTR : MMUEXT_NEW_USER_BASEPTR;
752         op->arg1.mfn = mfn;
753
754         MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
755
756         if (kernel) {
757                 x86_write_percpu(xen_cr3, cr3);
758
759                 /* Update xen_current_cr3 once the batch has actually
760                    been submitted. */
761                 xen_mc_callback(set_current_cr3, (void *)cr3);
762         }
763 }
764
765 static void xen_write_cr3(unsigned long cr3)
766 {
767         BUG_ON(preemptible());
768
769         xen_mc_batch();  /* disables interrupts */
770
771         /* Update while interrupts are disabled, so its atomic with
772            respect to ipis */
773         x86_write_percpu(xen_cr3, cr3);
774
775         __xen_write_cr3(true, cr3);
776
777 #ifdef CONFIG_X86_64
778         {
779                 pgd_t *user_pgd = xen_get_user_pgd(__va(cr3));
780                 if (user_pgd)
781                         __xen_write_cr3(false, __pa(user_pgd));
782                 else
783                         __xen_write_cr3(false, 0);
784         }
785 #endif
786
787         xen_mc_issue(PARAVIRT_LAZY_CPU);  /* interrupts restored */
788 }
789
790 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
791 {
792         int ret;
793
794         ret = 0;
795
796         switch(msr) {
797 #ifdef CONFIG_X86_64
798                 unsigned which;
799                 u64 base;
800
801         case MSR_FS_BASE:               which = SEGBASE_FS; goto set;
802         case MSR_KERNEL_GS_BASE:        which = SEGBASE_GS_USER; goto set;
803         case MSR_GS_BASE:               which = SEGBASE_GS_KERNEL; goto set;
804
805         set:
806                 base = ((u64)high << 32) | low;
807                 if (HYPERVISOR_set_segment_base(which, base) != 0)
808                         ret = -EFAULT;
809                 break;
810 #endif
811
812         case MSR_STAR:
813         case MSR_CSTAR:
814         case MSR_LSTAR:
815         case MSR_SYSCALL_MASK:
816         case MSR_IA32_SYSENTER_CS:
817         case MSR_IA32_SYSENTER_ESP:
818         case MSR_IA32_SYSENTER_EIP:
819                 /* Fast syscall setup is all done in hypercalls, so
820                    these are all ignored.  Stub them out here to stop
821                    Xen console noise. */
822                 break;
823
824         default:
825                 ret = native_write_msr_safe(msr, low, high);
826         }
827
828         return ret;
829 }
830
831 /* Early in boot, while setting up the initial pagetable, assume
832    everything is pinned. */
833 static __init void xen_alloc_pte_init(struct mm_struct *mm, unsigned long pfn)
834 {
835 #ifdef CONFIG_FLATMEM
836         BUG_ON(mem_map);        /* should only be used early */
837 #endif
838         make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
839 }
840
841 /* Early release_pte assumes that all pts are pinned, since there's
842    only init_mm and anything attached to that is pinned. */
843 static void xen_release_pte_init(unsigned long pfn)
844 {
845         make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
846 }
847
848 static void pin_pagetable_pfn(unsigned cmd, unsigned long pfn)
849 {
850         struct mmuext_op op;
851         op.cmd = cmd;
852         op.arg1.mfn = pfn_to_mfn(pfn);
853         if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
854                 BUG();
855 }
856
857 /* This needs to make sure the new pte page is pinned iff its being
858    attached to a pinned pagetable. */
859 static void xen_alloc_ptpage(struct mm_struct *mm, unsigned long pfn, unsigned level)
860 {
861         struct page *page = pfn_to_page(pfn);
862
863         if (PagePinned(virt_to_page(mm->pgd))) {
864                 SetPagePinned(page);
865
866                 if (!PageHighMem(page)) {
867                         make_lowmem_page_readonly(__va(PFN_PHYS((unsigned long)pfn)));
868                         if (level == PT_PTE && USE_SPLIT_PTLOCKS)
869                                 pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);
870                 } else
871                         /* make sure there are no stray mappings of
872                            this page */
873                         kmap_flush_unused();
874         }
875 }
876
877 static void xen_alloc_pte(struct mm_struct *mm, unsigned long pfn)
878 {
879         xen_alloc_ptpage(mm, pfn, PT_PTE);
880 }
881
882 static void xen_alloc_pmd(struct mm_struct *mm, unsigned long pfn)
883 {
884         xen_alloc_ptpage(mm, pfn, PT_PMD);
885 }
886
887 static int xen_pgd_alloc(struct mm_struct *mm)
888 {
889         pgd_t *pgd = mm->pgd;
890         int ret = 0;
891
892         BUG_ON(PagePinned(virt_to_page(pgd)));
893
894 #ifdef CONFIG_X86_64
895         {
896                 struct page *page = virt_to_page(pgd);
897                 pgd_t *user_pgd;
898
899                 BUG_ON(page->private != 0);
900
901                 ret = -ENOMEM;
902
903                 user_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
904                 page->private = (unsigned long)user_pgd;
905
906                 if (user_pgd != NULL) {
907                         user_pgd[pgd_index(VSYSCALL_START)] =
908                                 __pgd(__pa(level3_user_vsyscall) | _PAGE_TABLE);
909                         ret = 0;
910                 }
911
912                 BUG_ON(PagePinned(virt_to_page(xen_get_user_pgd(pgd))));
913         }
914 #endif
915
916         return ret;
917 }
918
919 static void xen_pgd_free(struct mm_struct *mm, pgd_t *pgd)
920 {
921 #ifdef CONFIG_X86_64
922         pgd_t *user_pgd = xen_get_user_pgd(pgd);
923
924         if (user_pgd)
925                 free_page((unsigned long)user_pgd);
926 #endif
927 }
928
929 /* This should never happen until we're OK to use struct page */
930 static void xen_release_ptpage(unsigned long pfn, unsigned level)
931 {
932         struct page *page = pfn_to_page(pfn);
933
934         if (PagePinned(page)) {
935                 if (!PageHighMem(page)) {
936                         if (level == PT_PTE && USE_SPLIT_PTLOCKS)
937                                 pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);
938                         make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
939                 }
940                 ClearPagePinned(page);
941         }
942 }
943
944 static void xen_release_pte(unsigned long pfn)
945 {
946         xen_release_ptpage(pfn, PT_PTE);
947 }
948
949 static void xen_release_pmd(unsigned long pfn)
950 {
951         xen_release_ptpage(pfn, PT_PMD);
952 }
953
954 #if PAGETABLE_LEVELS == 4
955 static void xen_alloc_pud(struct mm_struct *mm, unsigned long pfn)
956 {
957         xen_alloc_ptpage(mm, pfn, PT_PUD);
958 }
959
960 static void xen_release_pud(unsigned long pfn)
961 {
962         xen_release_ptpage(pfn, PT_PUD);
963 }
964 #endif
965
966 #ifdef CONFIG_HIGHPTE
967 static void *xen_kmap_atomic_pte(struct page *page, enum km_type type)
968 {
969         pgprot_t prot = PAGE_KERNEL;
970
971         if (PagePinned(page))
972                 prot = PAGE_KERNEL_RO;
973
974         if (0 && PageHighMem(page))
975                 printk("mapping highpte %lx type %d prot %s\n",
976                        page_to_pfn(page), type,
977                        (unsigned long)pgprot_val(prot) & _PAGE_RW ? "WRITE" : "READ");
978
979         return kmap_atomic_prot(page, type, prot);
980 }
981 #endif
982
983 #ifdef CONFIG_X86_32
984 static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
985 {
986         /* If there's an existing pte, then don't allow _PAGE_RW to be set */
987         if (pte_val_ma(*ptep) & _PAGE_PRESENT)
988                 pte = __pte_ma(((pte_val_ma(*ptep) & _PAGE_RW) | ~_PAGE_RW) &
989                                pte_val_ma(pte));
990
991         return pte;
992 }
993
994 /* Init-time set_pte while constructing initial pagetables, which
995    doesn't allow RO pagetable pages to be remapped RW */
996 static __init void xen_set_pte_init(pte_t *ptep, pte_t pte)
997 {
998         pte = mask_rw_pte(ptep, pte);
999
1000         xen_set_pte(ptep, pte);
1001 }
1002 #endif
1003
1004 static __init void xen_pagetable_setup_start(pgd_t *base)
1005 {
1006 }
1007
1008 void xen_setup_shared_info(void)
1009 {
1010         if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1011                 set_fixmap(FIX_PARAVIRT_BOOTMAP,
1012                            xen_start_info->shared_info);
1013
1014                 HYPERVISOR_shared_info =
1015                         (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
1016         } else
1017                 HYPERVISOR_shared_info =
1018                         (struct shared_info *)__va(xen_start_info->shared_info);
1019
1020 #ifndef CONFIG_SMP
1021         /* In UP this is as good a place as any to set up shared info */
1022         xen_setup_vcpu_info_placement();
1023 #endif
1024
1025         xen_setup_mfn_list_list();
1026 }
1027
1028 static __init void xen_pagetable_setup_done(pgd_t *base)
1029 {
1030         xen_setup_shared_info();
1031 }
1032
1033 static __init void xen_post_allocator_init(void)
1034 {
1035         pv_mmu_ops.set_pte = xen_set_pte;
1036         pv_mmu_ops.set_pmd = xen_set_pmd;
1037         pv_mmu_ops.set_pud = xen_set_pud;
1038 #if PAGETABLE_LEVELS == 4
1039         pv_mmu_ops.set_pgd = xen_set_pgd;
1040 #endif
1041
1042         /* This will work as long as patching hasn't happened yet
1043            (which it hasn't) */
1044         pv_mmu_ops.alloc_pte = xen_alloc_pte;
1045         pv_mmu_ops.alloc_pmd = xen_alloc_pmd;
1046         pv_mmu_ops.release_pte = xen_release_pte;
1047         pv_mmu_ops.release_pmd = xen_release_pmd;
1048 #if PAGETABLE_LEVELS == 4
1049         pv_mmu_ops.alloc_pud = xen_alloc_pud;
1050         pv_mmu_ops.release_pud = xen_release_pud;
1051 #endif
1052
1053 #ifdef CONFIG_X86_64
1054         SetPagePinned(virt_to_page(level3_user_vsyscall));
1055 #endif
1056         xen_mark_init_mm_pinned();
1057 }
1058
1059 /* This is called once we have the cpu_possible_map */
1060 void xen_setup_vcpu_info_placement(void)
1061 {
1062         int cpu;
1063
1064         for_each_possible_cpu(cpu)
1065                 xen_vcpu_setup(cpu);
1066
1067         /* xen_vcpu_setup managed to place the vcpu_info within the
1068            percpu area for all cpus, so make use of it */
1069         if (have_vcpu_info_placement) {
1070                 printk(KERN_INFO "Xen: using vcpu_info placement\n");
1071
1072                 pv_irq_ops.save_fl = xen_save_fl_direct;
1073                 pv_irq_ops.restore_fl = xen_restore_fl_direct;
1074                 pv_irq_ops.irq_disable = xen_irq_disable_direct;
1075                 pv_irq_ops.irq_enable = xen_irq_enable_direct;
1076                 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
1077         }
1078 }
1079
1080 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
1081                           unsigned long addr, unsigned len)
1082 {
1083         char *start, *end, *reloc;
1084         unsigned ret;
1085
1086         start = end = reloc = NULL;
1087
1088 #define SITE(op, x)                                                     \
1089         case PARAVIRT_PATCH(op.x):                                      \
1090         if (have_vcpu_info_placement) {                                 \
1091                 start = (char *)xen_##x##_direct;                       \
1092                 end = xen_##x##_direct_end;                             \
1093                 reloc = xen_##x##_direct_reloc;                         \
1094         }                                                               \
1095         goto patch_site
1096
1097         switch (type) {
1098                 SITE(pv_irq_ops, irq_enable);
1099                 SITE(pv_irq_ops, irq_disable);
1100                 SITE(pv_irq_ops, save_fl);
1101                 SITE(pv_irq_ops, restore_fl);
1102 #undef SITE
1103
1104         patch_site:
1105                 if (start == NULL || (end-start) > len)
1106                         goto default_patch;
1107
1108                 ret = paravirt_patch_insns(insnbuf, len, start, end);
1109
1110                 /* Note: because reloc is assigned from something that
1111                    appears to be an array, gcc assumes it's non-null,
1112                    but doesn't know its relationship with start and
1113                    end. */
1114                 if (reloc > start && reloc < end) {
1115                         int reloc_off = reloc - start;
1116                         long *relocp = (long *)(insnbuf + reloc_off);
1117                         long delta = start - (char *)addr;
1118
1119                         *relocp += delta;
1120                 }
1121                 break;
1122
1123         default_patch:
1124         default:
1125                 ret = paravirt_patch_default(type, clobbers, insnbuf,
1126                                              addr, len);
1127                 break;
1128         }
1129
1130         return ret;
1131 }
1132
1133 static void xen_set_fixmap(unsigned idx, unsigned long phys, pgprot_t prot)
1134 {
1135         pte_t pte;
1136
1137         phys >>= PAGE_SHIFT;
1138
1139         switch (idx) {
1140         case FIX_BTMAP_END ... FIX_BTMAP_BEGIN:
1141 #ifdef CONFIG_X86_F00F_BUG
1142         case FIX_F00F_IDT:
1143 #endif
1144 #ifdef CONFIG_X86_32
1145         case FIX_WP_TEST:
1146         case FIX_VDSO:
1147 # ifdef CONFIG_HIGHMEM
1148         case FIX_KMAP_BEGIN ... FIX_KMAP_END:
1149 # endif
1150 #else
1151         case VSYSCALL_LAST_PAGE ... VSYSCALL_FIRST_PAGE:
1152 #endif
1153 #ifdef CONFIG_X86_LOCAL_APIC
1154         case FIX_APIC_BASE:     /* maps dummy local APIC */
1155 #endif
1156                 pte = pfn_pte(phys, prot);
1157                 break;
1158
1159         default:
1160                 pte = mfn_pte(phys, prot);
1161                 break;
1162         }
1163
1164         __native_set_fixmap(idx, pte);
1165
1166 #ifdef CONFIG_X86_64
1167         /* Replicate changes to map the vsyscall page into the user
1168            pagetable vsyscall mapping. */
1169         if (idx >= VSYSCALL_LAST_PAGE && idx <= VSYSCALL_FIRST_PAGE) {
1170                 unsigned long vaddr = __fix_to_virt(idx);
1171                 set_pte_vaddr_pud(level3_user_vsyscall, vaddr, pte);
1172         }
1173 #endif
1174 }
1175
1176 static const struct pv_info xen_info __initdata = {
1177         .paravirt_enabled = 1,
1178         .shared_kernel_pmd = 0,
1179
1180         .name = "Xen",
1181 };
1182
1183 static const struct pv_init_ops xen_init_ops __initdata = {
1184         .patch = xen_patch,
1185
1186         .banner = xen_banner,
1187         .memory_setup = xen_memory_setup,
1188         .arch_setup = xen_arch_setup,
1189         .post_allocator_init = xen_post_allocator_init,
1190 };
1191
1192 static const struct pv_time_ops xen_time_ops __initdata = {
1193         .time_init = xen_time_init,
1194
1195         .set_wallclock = xen_set_wallclock,
1196         .get_wallclock = xen_get_wallclock,
1197         .get_tsc_khz = xen_tsc_khz,
1198         .sched_clock = xen_sched_clock,
1199 };
1200
1201 static const struct pv_cpu_ops xen_cpu_ops __initdata = {
1202         .cpuid = xen_cpuid,
1203
1204         .set_debugreg = xen_set_debugreg,
1205         .get_debugreg = xen_get_debugreg,
1206
1207         .clts = xen_clts,
1208
1209         .read_cr0 = native_read_cr0,
1210         .write_cr0 = xen_write_cr0,
1211
1212         .read_cr4 = native_read_cr4,
1213         .read_cr4_safe = native_read_cr4_safe,
1214         .write_cr4 = xen_write_cr4,
1215
1216         .wbinvd = native_wbinvd,
1217
1218         .read_msr = native_read_msr_safe,
1219         .write_msr = xen_write_msr_safe,
1220         .read_tsc = native_read_tsc,
1221         .read_pmc = native_read_pmc,
1222
1223         .iret = xen_iret,
1224         .irq_enable_sysexit = xen_sysexit,
1225 #ifdef CONFIG_X86_64
1226         .usergs_sysret32 = xen_sysret32,
1227         .usergs_sysret64 = xen_sysret64,
1228 #endif
1229
1230         .load_tr_desc = paravirt_nop,
1231         .set_ldt = xen_set_ldt,
1232         .load_gdt = xen_load_gdt,
1233         .load_idt = xen_load_idt,
1234         .load_tls = xen_load_tls,
1235 #ifdef CONFIG_X86_64
1236         .load_gs_index = xen_load_gs_index,
1237 #endif
1238
1239         .alloc_ldt = xen_alloc_ldt,
1240         .free_ldt = xen_free_ldt,
1241
1242         .store_gdt = native_store_gdt,
1243         .store_idt = native_store_idt,
1244         .store_tr = xen_store_tr,
1245
1246         .write_ldt_entry = xen_write_ldt_entry,
1247         .write_gdt_entry = xen_write_gdt_entry,
1248         .write_idt_entry = xen_write_idt_entry,
1249         .load_sp0 = xen_load_sp0,
1250
1251         .set_iopl_mask = xen_set_iopl_mask,
1252         .io_delay = xen_io_delay,
1253
1254         /* Xen takes care of %gs when switching to usermode for us */
1255         .swapgs = paravirt_nop,
1256
1257         .lazy_mode = {
1258                 .enter = paravirt_enter_lazy_cpu,
1259                 .leave = xen_leave_lazy,
1260         },
1261 };
1262
1263 static const struct pv_apic_ops xen_apic_ops __initdata = {
1264 #ifdef CONFIG_X86_LOCAL_APIC
1265         .setup_boot_clock = paravirt_nop,
1266         .setup_secondary_clock = paravirt_nop,
1267         .startup_ipi_hook = paravirt_nop,
1268 #endif
1269 };
1270
1271 static const struct pv_mmu_ops xen_mmu_ops __initdata = {
1272         .pagetable_setup_start = xen_pagetable_setup_start,
1273         .pagetable_setup_done = xen_pagetable_setup_done,
1274
1275         .read_cr2 = xen_read_cr2,
1276         .write_cr2 = xen_write_cr2,
1277
1278         .read_cr3 = xen_read_cr3,
1279         .write_cr3 = xen_write_cr3,
1280
1281         .flush_tlb_user = xen_flush_tlb,
1282         .flush_tlb_kernel = xen_flush_tlb,
1283         .flush_tlb_single = xen_flush_tlb_single,
1284         .flush_tlb_others = xen_flush_tlb_others,
1285
1286         .pte_update = paravirt_nop,
1287         .pte_update_defer = paravirt_nop,
1288
1289         .pgd_alloc = xen_pgd_alloc,
1290         .pgd_free = xen_pgd_free,
1291
1292         .alloc_pte = xen_alloc_pte_init,
1293         .release_pte = xen_release_pte_init,
1294         .alloc_pmd = xen_alloc_pte_init,
1295         .alloc_pmd_clone = paravirt_nop,
1296         .release_pmd = xen_release_pte_init,
1297
1298 #ifdef CONFIG_HIGHPTE
1299         .kmap_atomic_pte = xen_kmap_atomic_pte,
1300 #endif
1301
1302 #ifdef CONFIG_X86_64
1303         .set_pte = xen_set_pte,
1304 #else
1305         .set_pte = xen_set_pte_init,
1306 #endif
1307         .set_pte_at = xen_set_pte_at,
1308         .set_pmd = xen_set_pmd_hyper,
1309
1310         .ptep_modify_prot_start = __ptep_modify_prot_start,
1311         .ptep_modify_prot_commit = __ptep_modify_prot_commit,
1312
1313         .pte_val = xen_pte_val,
1314         .pte_flags = native_pte_flags,
1315         .pgd_val = xen_pgd_val,
1316
1317         .make_pte = xen_make_pte,
1318         .make_pgd = xen_make_pgd,
1319
1320 #ifdef CONFIG_X86_PAE
1321         .set_pte_atomic = xen_set_pte_atomic,
1322         .set_pte_present = xen_set_pte_at,
1323         .pte_clear = xen_pte_clear,
1324         .pmd_clear = xen_pmd_clear,
1325 #endif  /* CONFIG_X86_PAE */
1326         .set_pud = xen_set_pud_hyper,
1327
1328         .make_pmd = xen_make_pmd,
1329         .pmd_val = xen_pmd_val,
1330
1331 #if PAGETABLE_LEVELS == 4
1332         .pud_val = xen_pud_val,
1333         .make_pud = xen_make_pud,
1334         .set_pgd = xen_set_pgd_hyper,
1335
1336         .alloc_pud = xen_alloc_pte_init,
1337         .release_pud = xen_release_pte_init,
1338 #endif  /* PAGETABLE_LEVELS == 4 */
1339
1340         .activate_mm = xen_activate_mm,
1341         .dup_mmap = xen_dup_mmap,
1342         .exit_mmap = xen_exit_mmap,
1343
1344         .lazy_mode = {
1345                 .enter = paravirt_enter_lazy_mmu,
1346                 .leave = xen_leave_lazy,
1347         },
1348
1349         .set_fixmap = xen_set_fixmap,
1350 };
1351
1352 static void xen_reboot(int reason)
1353 {
1354         struct sched_shutdown r = { .reason = reason };
1355
1356 #ifdef CONFIG_SMP
1357         smp_send_stop();
1358 #endif
1359
1360         if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
1361                 BUG();
1362 }
1363
1364 static void xen_restart(char *msg)
1365 {
1366         xen_reboot(SHUTDOWN_reboot);
1367 }
1368
1369 static void xen_emergency_restart(void)
1370 {
1371         xen_reboot(SHUTDOWN_reboot);
1372 }
1373
1374 static void xen_machine_halt(void)
1375 {
1376         xen_reboot(SHUTDOWN_poweroff);
1377 }
1378
1379 static void xen_crash_shutdown(struct pt_regs *regs)
1380 {
1381         xen_reboot(SHUTDOWN_crash);
1382 }
1383
1384 static const struct machine_ops __initdata xen_machine_ops = {
1385         .restart = xen_restart,
1386         .halt = xen_machine_halt,
1387         .power_off = xen_machine_halt,
1388         .shutdown = xen_machine_halt,
1389         .crash_shutdown = xen_crash_shutdown,
1390         .emergency_restart = xen_emergency_restart,
1391 };
1392
1393
1394 static void __init xen_reserve_top(void)
1395 {
1396 #ifdef CONFIG_X86_32
1397         unsigned long top = HYPERVISOR_VIRT_START;
1398         struct xen_platform_parameters pp;
1399
1400         if (HYPERVISOR_xen_version(XENVER_platform_parameters, &pp) == 0)
1401                 top = pp.virt_start;
1402
1403         reserve_top_address(-top);
1404 #endif  /* CONFIG_X86_32 */
1405 }
1406
1407 /*
1408  * Like __va(), but returns address in the kernel mapping (which is
1409  * all we have until the physical memory mapping has been set up.
1410  */
1411 static void *__ka(phys_addr_t paddr)
1412 {
1413 #ifdef CONFIG_X86_64
1414         return (void *)(paddr + __START_KERNEL_map);
1415 #else
1416         return __va(paddr);
1417 #endif
1418 }
1419
1420 /* Convert a machine address to physical address */
1421 static unsigned long m2p(phys_addr_t maddr)
1422 {
1423         phys_addr_t paddr;
1424
1425         maddr &= PTE_PFN_MASK;
1426         paddr = mfn_to_pfn(maddr >> PAGE_SHIFT) << PAGE_SHIFT;
1427
1428         return paddr;
1429 }
1430
1431 /* Convert a machine address to kernel virtual */
1432 static void *m2v(phys_addr_t maddr)
1433 {
1434         return __ka(m2p(maddr));
1435 }
1436
1437 static void set_page_prot(void *addr, pgprot_t prot)
1438 {
1439         unsigned long pfn = __pa(addr) >> PAGE_SHIFT;
1440         pte_t pte = pfn_pte(pfn, prot);
1441
1442         if (HYPERVISOR_update_va_mapping((unsigned long)addr, pte, 0))
1443                 BUG();
1444 }
1445
1446 static __init void xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn)
1447 {
1448         unsigned pmdidx, pteidx;
1449         unsigned ident_pte;
1450         unsigned long pfn;
1451
1452         ident_pte = 0;
1453         pfn = 0;
1454         for(pmdidx = 0; pmdidx < PTRS_PER_PMD && pfn < max_pfn; pmdidx++) {
1455                 pte_t *pte_page;
1456
1457                 /* Reuse or allocate a page of ptes */
1458                 if (pmd_present(pmd[pmdidx]))
1459                         pte_page = m2v(pmd[pmdidx].pmd);
1460                 else {
1461                         /* Check for free pte pages */
1462                         if (ident_pte == ARRAY_SIZE(level1_ident_pgt))
1463                                 break;
1464
1465                         pte_page = &level1_ident_pgt[ident_pte];
1466                         ident_pte += PTRS_PER_PTE;
1467
1468                         pmd[pmdidx] = __pmd(__pa(pte_page) | _PAGE_TABLE);
1469                 }
1470
1471                 /* Install mappings */
1472                 for(pteidx = 0; pteidx < PTRS_PER_PTE; pteidx++, pfn++) {
1473                         pte_t pte;
1474
1475                         if (pfn > max_pfn_mapped)
1476                                 max_pfn_mapped = pfn;
1477
1478                         if (!pte_none(pte_page[pteidx]))
1479                                 continue;
1480
1481                         pte = pfn_pte(pfn, PAGE_KERNEL_EXEC);
1482                         pte_page[pteidx] = pte;
1483                 }
1484         }
1485
1486         for(pteidx = 0; pteidx < ident_pte; pteidx += PTRS_PER_PTE)
1487                 set_page_prot(&level1_ident_pgt[pteidx], PAGE_KERNEL_RO);
1488
1489         set_page_prot(pmd, PAGE_KERNEL_RO);
1490 }
1491
1492 #ifdef CONFIG_X86_64
1493 static void convert_pfn_mfn(void *v)
1494 {
1495         pte_t *pte = v;
1496         int i;
1497
1498         /* All levels are converted the same way, so just treat them
1499            as ptes. */
1500         for(i = 0; i < PTRS_PER_PTE; i++)
1501                 pte[i] = xen_make_pte(pte[i].pte);
1502 }
1503
1504 /*
1505  * Set up the inital kernel pagetable.
1506  *
1507  * We can construct this by grafting the Xen provided pagetable into
1508  * head_64.S's preconstructed pagetables.  We copy the Xen L2's into
1509  * level2_ident_pgt, level2_kernel_pgt and level2_fixmap_pgt.  This
1510  * means that only the kernel has a physical mapping to start with -
1511  * but that's enough to get __va working.  We need to fill in the rest
1512  * of the physical mapping once some sort of allocator has been set
1513  * up.
1514  */
1515 static __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
1516 {
1517         pud_t *l3;
1518         pmd_t *l2;
1519
1520         /* Zap identity mapping */
1521         init_level4_pgt[0] = __pgd(0);
1522
1523         /* Pre-constructed entries are in pfn, so convert to mfn */
1524         convert_pfn_mfn(init_level4_pgt);
1525         convert_pfn_mfn(level3_ident_pgt);
1526         convert_pfn_mfn(level3_kernel_pgt);
1527
1528         l3 = m2v(pgd[pgd_index(__START_KERNEL_map)].pgd);
1529         l2 = m2v(l3[pud_index(__START_KERNEL_map)].pud);
1530
1531         memcpy(level2_ident_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD);
1532         memcpy(level2_kernel_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD);
1533
1534         l3 = m2v(pgd[pgd_index(__START_KERNEL_map + PMD_SIZE)].pgd);
1535         l2 = m2v(l3[pud_index(__START_KERNEL_map + PMD_SIZE)].pud);
1536         memcpy(level2_fixmap_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD);
1537
1538         /* Set up identity map */
1539         xen_map_identity_early(level2_ident_pgt, max_pfn);
1540
1541         /* Make pagetable pieces RO */
1542         set_page_prot(init_level4_pgt, PAGE_KERNEL_RO);
1543         set_page_prot(level3_ident_pgt, PAGE_KERNEL_RO);
1544         set_page_prot(level3_kernel_pgt, PAGE_KERNEL_RO);
1545         set_page_prot(level3_user_vsyscall, PAGE_KERNEL_RO);
1546         set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO);
1547         set_page_prot(level2_fixmap_pgt, PAGE_KERNEL_RO);
1548
1549         /* Pin down new L4 */
1550         pin_pagetable_pfn(MMUEXT_PIN_L4_TABLE,
1551                           PFN_DOWN(__pa_symbol(init_level4_pgt)));
1552
1553         /* Unpin Xen-provided one */
1554         pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
1555
1556         /* Switch over */
1557         pgd = init_level4_pgt;
1558
1559         /*
1560          * At this stage there can be no user pgd, and no page
1561          * structure to attach it to, so make sure we just set kernel
1562          * pgd.
1563          */
1564         xen_mc_batch();
1565         __xen_write_cr3(true, __pa(pgd));
1566         xen_mc_issue(PARAVIRT_LAZY_CPU);
1567
1568         reserve_early(__pa(xen_start_info->pt_base),
1569                       __pa(xen_start_info->pt_base +
1570                            xen_start_info->nr_pt_frames * PAGE_SIZE),
1571                       "XEN PAGETABLES");
1572
1573         return pgd;
1574 }
1575 #else   /* !CONFIG_X86_64 */
1576 static pmd_t level2_kernel_pgt[PTRS_PER_PMD] __page_aligned_bss;
1577
1578 static __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn)
1579 {
1580         pmd_t *kernel_pmd;
1581
1582         init_pg_tables_start = __pa(pgd);
1583         init_pg_tables_end = __pa(pgd) + xen_start_info->nr_pt_frames*PAGE_SIZE;
1584         max_pfn_mapped = PFN_DOWN(init_pg_tables_end + 512*1024);
1585
1586         kernel_pmd = m2v(pgd[KERNEL_PGD_BOUNDARY].pgd);
1587         memcpy(level2_kernel_pgt, kernel_pmd, sizeof(pmd_t) * PTRS_PER_PMD);
1588
1589         xen_map_identity_early(level2_kernel_pgt, max_pfn);
1590
1591         memcpy(swapper_pg_dir, pgd, sizeof(pgd_t) * PTRS_PER_PGD);
1592         set_pgd(&swapper_pg_dir[KERNEL_PGD_BOUNDARY],
1593                         __pgd(__pa(level2_kernel_pgt) | _PAGE_PRESENT));
1594
1595         set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO);
1596         set_page_prot(swapper_pg_dir, PAGE_KERNEL_RO);
1597         set_page_prot(empty_zero_page, PAGE_KERNEL_RO);
1598
1599         pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
1600
1601         xen_write_cr3(__pa(swapper_pg_dir));
1602
1603         pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(swapper_pg_dir)));
1604
1605         return swapper_pg_dir;
1606 }
1607 #endif  /* CONFIG_X86_64 */
1608
1609 /* First C function to be called on Xen boot */
1610 asmlinkage void __init xen_start_kernel(void)
1611 {
1612         pgd_t *pgd;
1613
1614         if (!xen_start_info)
1615                 return;
1616
1617         xen_domain_type = XEN_PV_DOMAIN;
1618
1619         BUG_ON(memcmp(xen_start_info->magic, "xen-3", 5) != 0);
1620
1621         xen_setup_features();
1622
1623         /* Install Xen paravirt ops */
1624         pv_info = xen_info;
1625         pv_init_ops = xen_init_ops;
1626         pv_time_ops = xen_time_ops;
1627         pv_cpu_ops = xen_cpu_ops;
1628         pv_apic_ops = xen_apic_ops;
1629         pv_mmu_ops = xen_mmu_ops;
1630
1631         xen_init_irq_ops();
1632
1633 #ifdef CONFIG_X86_LOCAL_APIC
1634         /*
1635          * set up the basic apic ops.
1636          */
1637         apic_ops = &xen_basic_apic_ops;
1638 #endif
1639
1640         if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
1641                 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
1642                 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
1643         }
1644
1645         machine_ops = xen_machine_ops;
1646
1647 #ifdef CONFIG_X86_64
1648         /* Disable until direct per-cpu data access. */
1649         have_vcpu_info_placement = 0;
1650         x86_64_init_pda();
1651 #endif
1652
1653         xen_smp_init();
1654
1655         /* Get mfn list */
1656         if (!xen_feature(XENFEAT_auto_translated_physmap))
1657                 xen_build_dynamic_phys_to_machine();
1658
1659         pgd = (pgd_t *)xen_start_info->pt_base;
1660
1661         /* Prevent unwanted bits from being set in PTEs. */
1662         __supported_pte_mask &= ~_PAGE_GLOBAL;
1663         if (!xen_initial_domain())
1664                 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
1665
1666         /* Don't do the full vcpu_info placement stuff until we have a
1667            possible map and a non-dummy shared_info. */
1668         per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1669
1670         xen_raw_console_write("mapping kernel into physical memory\n");
1671         pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages);
1672
1673         init_mm.pgd = pgd;
1674
1675         /* keep using Xen gdt for now; no urgent need to change it */
1676
1677         pv_info.kernel_rpl = 1;
1678         if (xen_feature(XENFEAT_supervisor_mode_kernel))
1679                 pv_info.kernel_rpl = 0;
1680
1681         /* set the limit of our address space */
1682         xen_reserve_top();
1683
1684 #ifdef CONFIG_X86_32
1685         /* set up basic CPUID stuff */
1686         cpu_detect(&new_cpu_data);
1687         new_cpu_data.hard_math = 1;
1688         new_cpu_data.x86_capability[0] = cpuid_edx(1);
1689 #endif
1690
1691         /* Poke various useful things into boot_params */
1692         boot_params.hdr.type_of_loader = (9 << 4) | 0;
1693         boot_params.hdr.ramdisk_image = xen_start_info->mod_start
1694                 ? __pa(xen_start_info->mod_start) : 0;
1695         boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
1696         boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
1697
1698         if (!xen_initial_domain()) {
1699                 add_preferred_console("xenboot", 0, NULL);
1700                 add_preferred_console("tty", 0, NULL);
1701                 add_preferred_console("hvc", 0, NULL);
1702         }
1703
1704         xen_raw_console_write("about to get started...\n");
1705
1706         /* Start the world */
1707 #ifdef CONFIG_X86_32
1708         i386_start_kernel();
1709 #else
1710         x86_64_start_reservations((char *)__pa_symbol(&boot_params));
1711 #endif
1712 }