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-rw-r--r--arch/x86/xen/enlighten.c1146
1 files changed, 1146 insertions, 0 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
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index 000000000000..f01bfcd4bdee
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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/smp.h>
29
30#include <xen/interface/xen.h>
31#include <xen/interface/physdev.h>
32#include <xen/interface/vcpu.h>
33#include <xen/interface/sched.h>
34#include <xen/features.h>
35#include <xen/page.h>
36
37#include <asm/paravirt.h>
38#include <asm/page.h>
39#include <asm/xen/hypercall.h>
40#include <asm/xen/hypervisor.h>
41#include <asm/fixmap.h>
42#include <asm/processor.h>
43#include <asm/setup.h>
44#include <asm/desc.h>
45#include <asm/pgtable.h>
46#include <asm/tlbflush.h>
47#include <asm/reboot.h>
48
49#include "xen-ops.h"
50#include "mmu.h"
51#include "multicalls.h"
52
53EXPORT_SYMBOL_GPL(hypercall_page);
54
55DEFINE_PER_CPU(enum paravirt_lazy_mode, xen_lazy_mode);
56
57DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
58DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
59DEFINE_PER_CPU(unsigned long, xen_cr3);
60
61struct start_info *xen_start_info;
62EXPORT_SYMBOL_GPL(xen_start_info);
63
64static /* __initdata */ struct shared_info dummy_shared_info;
65
66/*
67 * Point at some empty memory to start with. We map the real shared_info
68 * page as soon as fixmap is up and running.
69 */
70struct shared_info *HYPERVISOR_shared_info = (void *)&dummy_shared_info;
71
72/*
73 * Flag to determine whether vcpu info placement is available on all
74 * VCPUs. We assume it is to start with, and then set it to zero on
75 * the first failure. This is because it can succeed on some VCPUs
76 * and not others, since it can involve hypervisor memory allocation,
77 * or because the guest failed to guarantee all the appropriate
78 * constraints on all VCPUs (ie buffer can't cross a page boundary).
79 *
80 * Note that any particular CPU may be using a placed vcpu structure,
81 * but we can only optimise if the all are.
82 *
83 * 0: not available, 1: available
84 */
85static int have_vcpu_info_placement = 1;
86
87static void __init xen_vcpu_setup(int cpu)
88{
89 struct vcpu_register_vcpu_info info;
90 int err;
91 struct vcpu_info *vcpup;
92
93 per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
94
95 if (!have_vcpu_info_placement)
96 return; /* already tested, not available */
97
98 vcpup = &per_cpu(xen_vcpu_info, cpu);
99
100 info.mfn = virt_to_mfn(vcpup);
101 info.offset = offset_in_page(vcpup);
102
103 printk(KERN_DEBUG "trying to map vcpu_info %d at %p, mfn %x, offset %d\n",
104 cpu, vcpup, info.mfn, info.offset);
105
106 /* Check to see if the hypervisor will put the vcpu_info
107 structure where we want it, which allows direct access via
108 a percpu-variable. */
109 err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
110
111 if (err) {
112 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
113 have_vcpu_info_placement = 0;
114 } else {
115 /* This cpu is using the registered vcpu info, even if
116 later ones fail to. */
117 per_cpu(xen_vcpu, cpu) = vcpup;
118
119 printk(KERN_DEBUG "cpu %d using vcpu_info at %p\n",
120 cpu, vcpup);
121 }
122}
123
124static void __init xen_banner(void)
125{
126 printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
127 paravirt_ops.name);
128 printk(KERN_INFO "Hypervisor signature: %s\n", xen_start_info->magic);
129}
130
131static void xen_cpuid(unsigned int *eax, unsigned int *ebx,
132 unsigned int *ecx, unsigned int *edx)
133{
134 unsigned maskedx = ~0;
135
136 /*
137 * Mask out inconvenient features, to try and disable as many
138 * unsupported kernel subsystems as possible.
139 */
140 if (*eax == 1)
141 maskedx = ~((1 << X86_FEATURE_APIC) | /* disable APIC */
142 (1 << X86_FEATURE_ACPI) | /* disable ACPI */
143 (1 << X86_FEATURE_ACC)); /* thermal monitoring */
144
145 asm(XEN_EMULATE_PREFIX "cpuid"
146 : "=a" (*eax),
147 "=b" (*ebx),
148 "=c" (*ecx),
149 "=d" (*edx)
150 : "0" (*eax), "2" (*ecx));
151 *edx &= maskedx;
152}
153
154static void xen_set_debugreg(int reg, unsigned long val)
155{
156 HYPERVISOR_set_debugreg(reg, val);
157}
158
159static unsigned long xen_get_debugreg(int reg)
160{
161 return HYPERVISOR_get_debugreg(reg);
162}
163
164static unsigned long xen_save_fl(void)
165{
166 struct vcpu_info *vcpu;
167 unsigned long flags;
168
169 vcpu = x86_read_percpu(xen_vcpu);
170
171 /* flag has opposite sense of mask */
172 flags = !vcpu->evtchn_upcall_mask;
173
174 /* convert to IF type flag
175 -0 -> 0x00000000
176 -1 -> 0xffffffff
177 */
178 return (-flags) & X86_EFLAGS_IF;
179}
180
181static void xen_restore_fl(unsigned long flags)
182{
183 struct vcpu_info *vcpu;
184
185 /* convert from IF type flag */
186 flags = !(flags & X86_EFLAGS_IF);
187
188 /* There's a one instruction preempt window here. We need to
189 make sure we're don't switch CPUs between getting the vcpu
190 pointer and updating the mask. */
191 preempt_disable();
192 vcpu = x86_read_percpu(xen_vcpu);
193 vcpu->evtchn_upcall_mask = flags;
194 preempt_enable_no_resched();
195
196 /* Doesn't matter if we get preempted here, because any
197 pending event will get dealt with anyway. */
198
199 if (flags == 0) {
200 preempt_check_resched();
201 barrier(); /* unmask then check (avoid races) */
202 if (unlikely(vcpu->evtchn_upcall_pending))
203 force_evtchn_callback();
204 }
205}
206
207static void xen_irq_disable(void)
208{
209 /* There's a one instruction preempt window here. We need to
210 make sure we're don't switch CPUs between getting the vcpu
211 pointer and updating the mask. */
212 preempt_disable();
213 x86_read_percpu(xen_vcpu)->evtchn_upcall_mask = 1;
214 preempt_enable_no_resched();
215}
216
217static void xen_irq_enable(void)
218{
219 struct vcpu_info *vcpu;
220
221 /* There's a one instruction preempt window here. We need to
222 make sure we're don't switch CPUs between getting the vcpu
223 pointer and updating the mask. */
224 preempt_disable();
225 vcpu = x86_read_percpu(xen_vcpu);
226 vcpu->evtchn_upcall_mask = 0;
227 preempt_enable_no_resched();
228
229 /* Doesn't matter if we get preempted here, because any
230 pending event will get dealt with anyway. */
231
232 barrier(); /* unmask then check (avoid races) */
233 if (unlikely(vcpu->evtchn_upcall_pending))
234 force_evtchn_callback();
235}
236
237static void xen_safe_halt(void)
238{
239 /* Blocking includes an implicit local_irq_enable(). */
240 if (HYPERVISOR_sched_op(SCHEDOP_block, 0) != 0)
241 BUG();
242}
243
244static void xen_halt(void)
245{
246 if (irqs_disabled())
247 HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
248 else
249 xen_safe_halt();
250}
251
252static void xen_set_lazy_mode(enum paravirt_lazy_mode mode)
253{
254 BUG_ON(preemptible());
255
256 switch (mode) {
257 case PARAVIRT_LAZY_NONE:
258 BUG_ON(x86_read_percpu(xen_lazy_mode) == PARAVIRT_LAZY_NONE);
259 break;
260
261 case PARAVIRT_LAZY_MMU:
262 case PARAVIRT_LAZY_CPU:
263 BUG_ON(x86_read_percpu(xen_lazy_mode) != PARAVIRT_LAZY_NONE);
264 break;
265
266 case PARAVIRT_LAZY_FLUSH:
267 /* flush if necessary, but don't change state */
268 if (x86_read_percpu(xen_lazy_mode) != PARAVIRT_LAZY_NONE)
269 xen_mc_flush();
270 return;
271 }
272
273 xen_mc_flush();
274 x86_write_percpu(xen_lazy_mode, mode);
275}
276
277static unsigned long xen_store_tr(void)
278{
279 return 0;
280}
281
282static void xen_set_ldt(const void *addr, unsigned entries)
283{
284 unsigned long linear_addr = (unsigned long)addr;
285 struct mmuext_op *op;
286 struct multicall_space mcs = xen_mc_entry(sizeof(*op));
287
288 op = mcs.args;
289 op->cmd = MMUEXT_SET_LDT;
290 if (linear_addr) {
291 /* ldt my be vmalloced, use arbitrary_virt_to_machine */
292 xmaddr_t maddr;
293 maddr = arbitrary_virt_to_machine((unsigned long)addr);
294 linear_addr = (unsigned long)maddr.maddr;
295 }
296 op->arg1.linear_addr = linear_addr;
297 op->arg2.nr_ents = entries;
298
299 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
300
301 xen_mc_issue(PARAVIRT_LAZY_CPU);
302}
303
304static void xen_load_gdt(const struct Xgt_desc_struct *dtr)
305{
306 unsigned long *frames;
307 unsigned long va = dtr->address;
308 unsigned int size = dtr->size + 1;
309 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
310 int f;
311 struct multicall_space mcs;
312
313 /* A GDT can be up to 64k in size, which corresponds to 8192
314 8-byte entries, or 16 4k pages.. */
315
316 BUG_ON(size > 65536);
317 BUG_ON(va & ~PAGE_MASK);
318
319 mcs = xen_mc_entry(sizeof(*frames) * pages);
320 frames = mcs.args;
321
322 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
323 frames[f] = virt_to_mfn(va);
324 make_lowmem_page_readonly((void *)va);
325 }
326
327 MULTI_set_gdt(mcs.mc, frames, size / sizeof(struct desc_struct));
328
329 xen_mc_issue(PARAVIRT_LAZY_CPU);
330}
331
332static void load_TLS_descriptor(struct thread_struct *t,
333 unsigned int cpu, unsigned int i)
334{
335 struct desc_struct *gdt = get_cpu_gdt_table(cpu);
336 xmaddr_t maddr = virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
337 struct multicall_space mc = __xen_mc_entry(0);
338
339 MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
340}
341
342static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
343{
344 xen_mc_batch();
345
346 load_TLS_descriptor(t, cpu, 0);
347 load_TLS_descriptor(t, cpu, 1);
348 load_TLS_descriptor(t, cpu, 2);
349
350 xen_mc_issue(PARAVIRT_LAZY_CPU);
351
352 /*
353 * XXX sleazy hack: If we're being called in a lazy-cpu zone,
354 * it means we're in a context switch, and %gs has just been
355 * saved. This means we can zero it out to prevent faults on
356 * exit from the hypervisor if the next process has no %gs.
357 * Either way, it has been saved, and the new value will get
358 * loaded properly. This will go away as soon as Xen has been
359 * modified to not save/restore %gs for normal hypercalls.
360 */
361 if (xen_get_lazy_mode() == PARAVIRT_LAZY_CPU)
362 loadsegment(gs, 0);
363}
364
365static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
366 u32 low, u32 high)
367{
368 unsigned long lp = (unsigned long)&dt[entrynum];
369 xmaddr_t mach_lp = virt_to_machine(lp);
370 u64 entry = (u64)high << 32 | low;
371
372 preempt_disable();
373
374 xen_mc_flush();
375 if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
376 BUG();
377
378 preempt_enable();
379}
380
381static int cvt_gate_to_trap(int vector, u32 low, u32 high,
382 struct trap_info *info)
383{
384 u8 type, dpl;
385
386 type = (high >> 8) & 0x1f;
387 dpl = (high >> 13) & 3;
388
389 if (type != 0xf && type != 0xe)
390 return 0;
391
392 info->vector = vector;
393 info->address = (high & 0xffff0000) | (low & 0x0000ffff);
394 info->cs = low >> 16;
395 info->flags = dpl;
396 /* interrupt gates clear IF */
397 if (type == 0xe)
398 info->flags |= 4;
399
400 return 1;
401}
402
403/* Locations of each CPU's IDT */
404static DEFINE_PER_CPU(struct Xgt_desc_struct, idt_desc);
405
406/* Set an IDT entry. If the entry is part of the current IDT, then
407 also update Xen. */
408static void xen_write_idt_entry(struct desc_struct *dt, int entrynum,
409 u32 low, u32 high)
410{
411 unsigned long p = (unsigned long)&dt[entrynum];
412 unsigned long start, end;
413
414 preempt_disable();
415
416 start = __get_cpu_var(idt_desc).address;
417 end = start + __get_cpu_var(idt_desc).size + 1;
418
419 xen_mc_flush();
420
421 write_dt_entry(dt, entrynum, low, high);
422
423 if (p >= start && (p + 8) <= end) {
424 struct trap_info info[2];
425
426 info[1].address = 0;
427
428 if (cvt_gate_to_trap(entrynum, low, high, &info[0]))
429 if (HYPERVISOR_set_trap_table(info))
430 BUG();
431 }
432
433 preempt_enable();
434}
435
436static void xen_convert_trap_info(const struct Xgt_desc_struct *desc,
437 struct trap_info *traps)
438{
439 unsigned in, out, count;
440
441 count = (desc->size+1) / 8;
442 BUG_ON(count > 256);
443
444 for (in = out = 0; in < count; in++) {
445 const u32 *entry = (u32 *)(desc->address + in * 8);
446
447 if (cvt_gate_to_trap(in, entry[0], entry[1], &traps[out]))
448 out++;
449 }
450 traps[out].address = 0;
451}
452
453void xen_copy_trap_info(struct trap_info *traps)
454{
455 const struct Xgt_desc_struct *desc = &__get_cpu_var(idt_desc);
456
457 xen_convert_trap_info(desc, traps);
458}
459
460/* Load a new IDT into Xen. In principle this can be per-CPU, so we
461 hold a spinlock to protect the static traps[] array (static because
462 it avoids allocation, and saves stack space). */
463static void xen_load_idt(const struct Xgt_desc_struct *desc)
464{
465 static DEFINE_SPINLOCK(lock);
466 static struct trap_info traps[257];
467
468 spin_lock(&lock);
469
470 __get_cpu_var(idt_desc) = *desc;
471
472 xen_convert_trap_info(desc, traps);
473
474 xen_mc_flush();
475 if (HYPERVISOR_set_trap_table(traps))
476 BUG();
477
478 spin_unlock(&lock);
479}
480
481/* Write a GDT descriptor entry. Ignore LDT descriptors, since
482 they're handled differently. */
483static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
484 u32 low, u32 high)
485{
486 preempt_disable();
487
488 switch ((high >> 8) & 0xff) {
489 case DESCTYPE_LDT:
490 case DESCTYPE_TSS:
491 /* ignore */
492 break;
493
494 default: {
495 xmaddr_t maddr = virt_to_machine(&dt[entry]);
496 u64 desc = (u64)high << 32 | low;
497
498 xen_mc_flush();
499 if (HYPERVISOR_update_descriptor(maddr.maddr, desc))
500 BUG();
501 }
502
503 }
504
505 preempt_enable();
506}
507
508static void xen_load_esp0(struct tss_struct *tss,
509 struct thread_struct *thread)
510{
511 struct multicall_space mcs = xen_mc_entry(0);
512 MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->esp0);
513 xen_mc_issue(PARAVIRT_LAZY_CPU);
514}
515
516static void xen_set_iopl_mask(unsigned mask)
517{
518 struct physdev_set_iopl set_iopl;
519
520 /* Force the change at ring 0. */
521 set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
522 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
523}
524
525static void xen_io_delay(void)
526{
527}
528
529#ifdef CONFIG_X86_LOCAL_APIC
530static unsigned long xen_apic_read(unsigned long reg)
531{
532 return 0;
533}
534
535static void xen_apic_write(unsigned long reg, unsigned long val)
536{
537 /* Warn to see if there's any stray references */
538 WARN_ON(1);
539}
540#endif
541
542static void xen_flush_tlb(void)
543{
544 struct mmuext_op *op;
545 struct multicall_space mcs = xen_mc_entry(sizeof(*op));
546
547 op = mcs.args;
548 op->cmd = MMUEXT_TLB_FLUSH_LOCAL;
549 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
550
551 xen_mc_issue(PARAVIRT_LAZY_MMU);
552}
553
554static void xen_flush_tlb_single(unsigned long addr)
555{
556 struct mmuext_op *op;
557 struct multicall_space mcs = xen_mc_entry(sizeof(*op));
558
559 op = mcs.args;
560 op->cmd = MMUEXT_INVLPG_LOCAL;
561 op->arg1.linear_addr = addr & PAGE_MASK;
562 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
563
564 xen_mc_issue(PARAVIRT_LAZY_MMU);
565}
566
567static void xen_flush_tlb_others(const cpumask_t *cpus, struct mm_struct *mm,
568 unsigned long va)
569{
570 struct {
571 struct mmuext_op op;
572 cpumask_t mask;
573 } *args;
574 cpumask_t cpumask = *cpus;
575 struct multicall_space mcs;
576
577 /*
578 * A couple of (to be removed) sanity checks:
579 *
580 * - current CPU must not be in mask
581 * - mask must exist :)
582 */
583 BUG_ON(cpus_empty(cpumask));
584 BUG_ON(cpu_isset(smp_processor_id(), cpumask));
585 BUG_ON(!mm);
586
587 /* If a CPU which we ran on has gone down, OK. */
588 cpus_and(cpumask, cpumask, cpu_online_map);
589 if (cpus_empty(cpumask))
590 return;
591
592 mcs = xen_mc_entry(sizeof(*args));
593 args = mcs.args;
594 args->mask = cpumask;
595 args->op.arg2.vcpumask = &args->mask;
596
597 if (va == TLB_FLUSH_ALL) {
598 args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
599 } else {
600 args->op.cmd = MMUEXT_INVLPG_MULTI;
601 args->op.arg1.linear_addr = va;
602 }
603
604 MULTI_mmuext_op(mcs.mc, &args->op, 1, NULL, DOMID_SELF);
605
606 xen_mc_issue(PARAVIRT_LAZY_MMU);
607}
608
609static void xen_write_cr2(unsigned long cr2)
610{
611 x86_read_percpu(xen_vcpu)->arch.cr2 = cr2;
612}
613
614static unsigned long xen_read_cr2(void)
615{
616 return x86_read_percpu(xen_vcpu)->arch.cr2;
617}
618
619static unsigned long xen_read_cr2_direct(void)
620{
621 return x86_read_percpu(xen_vcpu_info.arch.cr2);
622}
623
624static void xen_write_cr4(unsigned long cr4)
625{
626 /* Just ignore cr4 changes; Xen doesn't allow us to do
627 anything anyway. */
628}
629
630static unsigned long xen_read_cr3(void)
631{
632 return x86_read_percpu(xen_cr3);
633}
634
635static void xen_write_cr3(unsigned long cr3)
636{
637 BUG_ON(preemptible());
638
639 if (cr3 == x86_read_percpu(xen_cr3)) {
640 /* just a simple tlb flush */
641 xen_flush_tlb();
642 return;
643 }
644
645 x86_write_percpu(xen_cr3, cr3);
646
647
648 {
649 struct mmuext_op *op;
650 struct multicall_space mcs = xen_mc_entry(sizeof(*op));
651 unsigned long mfn = pfn_to_mfn(PFN_DOWN(cr3));
652
653 op = mcs.args;
654 op->cmd = MMUEXT_NEW_BASEPTR;
655 op->arg1.mfn = mfn;
656
657 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
658
659 xen_mc_issue(PARAVIRT_LAZY_CPU);
660 }
661}
662
663/* Early in boot, while setting up the initial pagetable, assume
664 everything is pinned. */
665static __init void xen_alloc_pt_init(struct mm_struct *mm, u32 pfn)
666{
667 BUG_ON(mem_map); /* should only be used early */
668 make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
669}
670
671/* This needs to make sure the new pte page is pinned iff its being
672 attached to a pinned pagetable. */
673static void xen_alloc_pt(struct mm_struct *mm, u32 pfn)
674{
675 struct page *page = pfn_to_page(pfn);
676
677 if (PagePinned(virt_to_page(mm->pgd))) {
678 SetPagePinned(page);
679
680 if (!PageHighMem(page))
681 make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
682 else
683 /* make sure there are no stray mappings of
684 this page */
685 kmap_flush_unused();
686 }
687}
688
689/* This should never happen until we're OK to use struct page */
690static void xen_release_pt(u32 pfn)
691{
692 struct page *page = pfn_to_page(pfn);
693
694 if (PagePinned(page)) {
695 if (!PageHighMem(page))
696 make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
697 }
698}
699
700#ifdef CONFIG_HIGHPTE
701static void *xen_kmap_atomic_pte(struct page *page, enum km_type type)
702{
703 pgprot_t prot = PAGE_KERNEL;
704
705 if (PagePinned(page))
706 prot = PAGE_KERNEL_RO;
707
708 if (0 && PageHighMem(page))
709 printk("mapping highpte %lx type %d prot %s\n",
710 page_to_pfn(page), type,
711 (unsigned long)pgprot_val(prot) & _PAGE_RW ? "WRITE" : "READ");
712
713 return kmap_atomic_prot(page, type, prot);
714}
715#endif
716
717static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
718{
719 /* If there's an existing pte, then don't allow _PAGE_RW to be set */
720 if (pte_val_ma(*ptep) & _PAGE_PRESENT)
721 pte = __pte_ma(((pte_val_ma(*ptep) & _PAGE_RW) | ~_PAGE_RW) &
722 pte_val_ma(pte));
723
724 return pte;
725}
726
727/* Init-time set_pte while constructing initial pagetables, which
728 doesn't allow RO pagetable pages to be remapped RW */
729static __init void xen_set_pte_init(pte_t *ptep, pte_t pte)
730{
731 pte = mask_rw_pte(ptep, pte);
732
733 xen_set_pte(ptep, pte);
734}
735
736static __init void xen_pagetable_setup_start(pgd_t *base)
737{
738 pgd_t *xen_pgd = (pgd_t *)xen_start_info->pt_base;
739
740 /* special set_pte for pagetable initialization */
741 paravirt_ops.set_pte = xen_set_pte_init;
742
743 init_mm.pgd = base;
744 /*
745 * copy top-level of Xen-supplied pagetable into place. For
746 * !PAE we can use this as-is, but for PAE it is a stand-in
747 * while we copy the pmd pages.
748 */
749 memcpy(base, xen_pgd, PTRS_PER_PGD * sizeof(pgd_t));
750
751 if (PTRS_PER_PMD > 1) {
752 int i;
753 /*
754 * For PAE, need to allocate new pmds, rather than
755 * share Xen's, since Xen doesn't like pmd's being
756 * shared between address spaces.
757 */
758 for (i = 0; i < PTRS_PER_PGD; i++) {
759 if (pgd_val_ma(xen_pgd[i]) & _PAGE_PRESENT) {
760 pmd_t *pmd = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);
761
762 memcpy(pmd, (void *)pgd_page_vaddr(xen_pgd[i]),
763 PAGE_SIZE);
764
765 make_lowmem_page_readonly(pmd);
766
767 set_pgd(&base[i], __pgd(1 + __pa(pmd)));
768 } else
769 pgd_clear(&base[i]);
770 }
771 }
772
773 /* make sure zero_page is mapped RO so we can use it in pagetables */
774 make_lowmem_page_readonly(empty_zero_page);
775 make_lowmem_page_readonly(base);
776 /*
777 * Switch to new pagetable. This is done before
778 * pagetable_init has done anything so that the new pages
779 * added to the table can be prepared properly for Xen.
780 */
781 xen_write_cr3(__pa(base));
782}
783
784static __init void xen_pagetable_setup_done(pgd_t *base)
785{
786 /* This will work as long as patching hasn't happened yet
787 (which it hasn't) */
788 paravirt_ops.alloc_pt = xen_alloc_pt;
789 paravirt_ops.set_pte = xen_set_pte;
790
791 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
792 /*
793 * Create a mapping for the shared info page.
794 * Should be set_fixmap(), but shared_info is a machine
795 * address with no corresponding pseudo-phys address.
796 */
797 set_pte_mfn(fix_to_virt(FIX_PARAVIRT_BOOTMAP),
798 PFN_DOWN(xen_start_info->shared_info),
799 PAGE_KERNEL);
800
801 HYPERVISOR_shared_info =
802 (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
803
804 } else
805 HYPERVISOR_shared_info =
806 (struct shared_info *)__va(xen_start_info->shared_info);
807
808 /* Actually pin the pagetable down, but we can't set PG_pinned
809 yet because the page structures don't exist yet. */
810 {
811 struct mmuext_op op;
812#ifdef CONFIG_X86_PAE
813 op.cmd = MMUEXT_PIN_L3_TABLE;
814#else
815 op.cmd = MMUEXT_PIN_L3_TABLE;
816#endif
817 op.arg1.mfn = pfn_to_mfn(PFN_DOWN(__pa(base)));
818 if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
819 BUG();
820 }
821}
822
823/* This is called once we have the cpu_possible_map */
824void __init xen_setup_vcpu_info_placement(void)
825{
826 int cpu;
827
828 for_each_possible_cpu(cpu)
829 xen_vcpu_setup(cpu);
830
831 /* xen_vcpu_setup managed to place the vcpu_info within the
832 percpu area for all cpus, so make use of it */
833 if (have_vcpu_info_placement) {
834 printk(KERN_INFO "Xen: using vcpu_info placement\n");
835
836 paravirt_ops.save_fl = xen_save_fl_direct;
837 paravirt_ops.restore_fl = xen_restore_fl_direct;
838 paravirt_ops.irq_disable = xen_irq_disable_direct;
839 paravirt_ops.irq_enable = xen_irq_enable_direct;
840 paravirt_ops.read_cr2 = xen_read_cr2_direct;
841 paravirt_ops.iret = xen_iret_direct;
842 }
843}
844
845static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
846 unsigned long addr, unsigned len)
847{
848 char *start, *end, *reloc;
849 unsigned ret;
850
851 start = end = reloc = NULL;
852
853#define SITE(x) \
854 case PARAVIRT_PATCH(x): \
855 if (have_vcpu_info_placement) { \
856 start = (char *)xen_##x##_direct; \
857 end = xen_##x##_direct_end; \
858 reloc = xen_##x##_direct_reloc; \
859 } \
860 goto patch_site
861
862 switch (type) {
863 SITE(irq_enable);
864 SITE(irq_disable);
865 SITE(save_fl);
866 SITE(restore_fl);
867#undef SITE
868
869 patch_site:
870 if (start == NULL || (end-start) > len)
871 goto default_patch;
872
873 ret = paravirt_patch_insns(insnbuf, len, start, end);
874
875 /* Note: because reloc is assigned from something that
876 appears to be an array, gcc assumes it's non-null,
877 but doesn't know its relationship with start and
878 end. */
879 if (reloc > start && reloc < end) {
880 int reloc_off = reloc - start;
881 long *relocp = (long *)(insnbuf + reloc_off);
882 long delta = start - (char *)addr;
883
884 *relocp += delta;
885 }
886 break;
887
888 default_patch:
889 default:
890 ret = paravirt_patch_default(type, clobbers, insnbuf,
891 addr, len);
892 break;
893 }
894
895 return ret;
896}
897
898static const struct paravirt_ops xen_paravirt_ops __initdata = {
899 .paravirt_enabled = 1,
900 .shared_kernel_pmd = 0,
901
902 .name = "Xen",
903 .banner = xen_banner,
904
905 .patch = xen_patch,
906
907 .memory_setup = xen_memory_setup,
908 .arch_setup = xen_arch_setup,
909 .init_IRQ = xen_init_IRQ,
910 .post_allocator_init = xen_mark_init_mm_pinned,
911
912 .time_init = xen_time_init,
913 .set_wallclock = xen_set_wallclock,
914 .get_wallclock = xen_get_wallclock,
915 .get_cpu_khz = xen_cpu_khz,
916 .sched_clock = xen_sched_clock,
917
918 .cpuid = xen_cpuid,
919
920 .set_debugreg = xen_set_debugreg,
921 .get_debugreg = xen_get_debugreg,
922
923 .clts = native_clts,
924
925 .read_cr0 = native_read_cr0,
926 .write_cr0 = native_write_cr0,
927
928 .read_cr2 = xen_read_cr2,
929 .write_cr2 = xen_write_cr2,
930
931 .read_cr3 = xen_read_cr3,
932 .write_cr3 = xen_write_cr3,
933
934 .read_cr4 = native_read_cr4,
935 .read_cr4_safe = native_read_cr4_safe,
936 .write_cr4 = xen_write_cr4,
937
938 .save_fl = xen_save_fl,
939 .restore_fl = xen_restore_fl,
940 .irq_disable = xen_irq_disable,
941 .irq_enable = xen_irq_enable,
942 .safe_halt = xen_safe_halt,
943 .halt = xen_halt,
944 .wbinvd = native_wbinvd,
945
946 .read_msr = native_read_msr_safe,
947 .write_msr = native_write_msr_safe,
948 .read_tsc = native_read_tsc,
949 .read_pmc = native_read_pmc,
950
951 .iret = (void *)&hypercall_page[__HYPERVISOR_iret],
952 .irq_enable_sysexit = NULL, /* never called */
953
954 .load_tr_desc = paravirt_nop,
955 .set_ldt = xen_set_ldt,
956 .load_gdt = xen_load_gdt,
957 .load_idt = xen_load_idt,
958 .load_tls = xen_load_tls,
959
960 .store_gdt = native_store_gdt,
961 .store_idt = native_store_idt,
962 .store_tr = xen_store_tr,
963
964 .write_ldt_entry = xen_write_ldt_entry,
965 .write_gdt_entry = xen_write_gdt_entry,
966 .write_idt_entry = xen_write_idt_entry,
967 .load_esp0 = xen_load_esp0,
968
969 .set_iopl_mask = xen_set_iopl_mask,
970 .io_delay = xen_io_delay,
971
972#ifdef CONFIG_X86_LOCAL_APIC
973 .apic_write = xen_apic_write,
974 .apic_write_atomic = xen_apic_write,
975 .apic_read = xen_apic_read,
976 .setup_boot_clock = paravirt_nop,
977 .setup_secondary_clock = paravirt_nop,
978 .startup_ipi_hook = paravirt_nop,
979#endif
980
981 .flush_tlb_user = xen_flush_tlb,
982 .flush_tlb_kernel = xen_flush_tlb,
983 .flush_tlb_single = xen_flush_tlb_single,
984 .flush_tlb_others = xen_flush_tlb_others,
985
986 .pte_update = paravirt_nop,
987 .pte_update_defer = paravirt_nop,
988
989 .pagetable_setup_start = xen_pagetable_setup_start,
990 .pagetable_setup_done = xen_pagetable_setup_done,
991
992 .alloc_pt = xen_alloc_pt_init,
993 .release_pt = xen_release_pt,
994 .alloc_pd = paravirt_nop,
995 .alloc_pd_clone = paravirt_nop,
996 .release_pd = paravirt_nop,
997
998#ifdef CONFIG_HIGHPTE
999 .kmap_atomic_pte = xen_kmap_atomic_pte,
1000#endif
1001
1002 .set_pte = NULL, /* see xen_pagetable_setup_* */
1003 .set_pte_at = xen_set_pte_at,
1004 .set_pmd = xen_set_pmd,
1005
1006 .pte_val = xen_pte_val,
1007 .pgd_val = xen_pgd_val,
1008
1009 .make_pte = xen_make_pte,
1010 .make_pgd = xen_make_pgd,
1011
1012#ifdef CONFIG_X86_PAE
1013 .set_pte_atomic = xen_set_pte_atomic,
1014 .set_pte_present = xen_set_pte_at,
1015 .set_pud = xen_set_pud,
1016 .pte_clear = xen_pte_clear,
1017 .pmd_clear = xen_pmd_clear,
1018
1019 .make_pmd = xen_make_pmd,
1020 .pmd_val = xen_pmd_val,
1021#endif /* PAE */
1022
1023 .activate_mm = xen_activate_mm,
1024 .dup_mmap = xen_dup_mmap,
1025 .exit_mmap = xen_exit_mmap,
1026
1027 .set_lazy_mode = xen_set_lazy_mode,
1028};
1029
1030#ifdef CONFIG_SMP
1031static const struct smp_ops xen_smp_ops __initdata = {
1032 .smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
1033 .smp_prepare_cpus = xen_smp_prepare_cpus,
1034 .cpu_up = xen_cpu_up,
1035 .smp_cpus_done = xen_smp_cpus_done,
1036
1037 .smp_send_stop = xen_smp_send_stop,
1038 .smp_send_reschedule = xen_smp_send_reschedule,
1039 .smp_call_function_mask = xen_smp_call_function_mask,
1040};
1041#endif /* CONFIG_SMP */
1042
1043static void xen_reboot(int reason)
1044{
1045#ifdef CONFIG_SMP
1046 smp_send_stop();
1047#endif
1048
1049 if (HYPERVISOR_sched_op(SCHEDOP_shutdown, reason))
1050 BUG();
1051}
1052
1053static void xen_restart(char *msg)
1054{
1055 xen_reboot(SHUTDOWN_reboot);
1056}
1057
1058static void xen_emergency_restart(void)
1059{
1060 xen_reboot(SHUTDOWN_reboot);
1061}
1062
1063static void xen_machine_halt(void)
1064{
1065 xen_reboot(SHUTDOWN_poweroff);
1066}
1067
1068static void xen_crash_shutdown(struct pt_regs *regs)
1069{
1070 xen_reboot(SHUTDOWN_crash);
1071}
1072
1073static const struct machine_ops __initdata xen_machine_ops = {
1074 .restart = xen_restart,
1075 .halt = xen_machine_halt,
1076 .power_off = xen_machine_halt,
1077 .shutdown = xen_machine_halt,
1078 .crash_shutdown = xen_crash_shutdown,
1079 .emergency_restart = xen_emergency_restart,
1080};
1081
1082
1083/* First C function to be called on Xen boot */
1084asmlinkage void __init xen_start_kernel(void)
1085{
1086 pgd_t *pgd;
1087
1088 if (!xen_start_info)
1089 return;
1090
1091 BUG_ON(memcmp(xen_start_info->magic, "xen-3.0", 7) != 0);
1092
1093 /* Install Xen paravirt ops */
1094 paravirt_ops = xen_paravirt_ops;
1095 machine_ops = xen_machine_ops;
1096
1097#ifdef CONFIG_SMP
1098 smp_ops = xen_smp_ops;
1099#endif
1100
1101 xen_setup_features();
1102
1103 /* Get mfn list */
1104 if (!xen_feature(XENFEAT_auto_translated_physmap))
1105 phys_to_machine_mapping = (unsigned long *)xen_start_info->mfn_list;
1106
1107 pgd = (pgd_t *)xen_start_info->pt_base;
1108
1109 init_pg_tables_end = __pa(pgd) + xen_start_info->nr_pt_frames*PAGE_SIZE;
1110
1111 init_mm.pgd = pgd; /* use the Xen pagetables to start */
1112
1113 /* keep using Xen gdt for now; no urgent need to change it */
1114
1115 x86_write_percpu(xen_cr3, __pa(pgd));
1116
1117#ifdef CONFIG_SMP
1118 /* Don't do the full vcpu_info placement stuff until we have a
1119 possible map. */
1120 per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1121#else
1122 /* May as well do it now, since there's no good time to call
1123 it later on UP. */
1124 xen_setup_vcpu_info_placement();
1125#endif
1126
1127 paravirt_ops.kernel_rpl = 1;
1128 if (xen_feature(XENFEAT_supervisor_mode_kernel))
1129 paravirt_ops.kernel_rpl = 0;
1130
1131 /* set the limit of our address space */
1132 reserve_top_address(-HYPERVISOR_VIRT_START + 2 * PAGE_SIZE);
1133
1134 /* set up basic CPUID stuff */
1135 cpu_detect(&new_cpu_data);
1136 new_cpu_data.hard_math = 1;
1137 new_cpu_data.x86_capability[0] = cpuid_edx(1);
1138
1139 /* Poke various useful things into boot_params */
1140 LOADER_TYPE = (9 << 4) | 0;
1141 INITRD_START = xen_start_info->mod_start ? __pa(xen_start_info->mod_start) : 0;
1142 INITRD_SIZE = xen_start_info->mod_len;
1143
1144 /* Start the world */
1145 start_kernel();
1146}