1 /*
2 * Core of Xen paravirt_ops implementation.
3 *
4 * This file contains the xen_paravirt_ops structure itself, and the
5 * implementations for:
6 * - privileged instructions
7 * - interrupt flags
8 * - segment operations
9 * - booting and setup
10 *
11 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
12 */
13
14 #include <linux/cpu.h>
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/smp.h>
18 #include <linux/preempt.h>
19 #include <linux/hardirq.h>
20 #include <linux/percpu.h>
21 #include <linux/delay.h>
22 #include <linux/start_kernel.h>
23 #include <linux/sched.h>
24 #include <linux/kprobes.h>
25 #include <linux/bootmem.h>
26 #include <linux/module.h>
27 #include <linux/mm.h>
28 #include <linux/page-flags.h>
29 #include <linux/highmem.h>
30 #include <linux/console.h>
31 #include <linux/pci.h>
32 #include <linux/gfp.h>
33 #include <linux/memblock.h>
34
35 #include <xen/xen.h>
36 #include <xen/interface/xen.h>
37 #include <xen/interface/version.h>
38 #include <xen/interface/physdev.h>
39 #include <xen/interface/vcpu.h>
40 #include <xen/interface/memory.h>
41 #include <xen/features.h>
42 #include <xen/page.h>
43 #include <xen/hvm.h>
44 #include <xen/hvc-console.h>
45
46 #include <asm/paravirt.h>
47 #include <asm/apic.h>
48 #include <asm/page.h>
49 #include <asm/xen/pci.h>
50 #include <asm/xen/hypercall.h>
51 #include <asm/xen/hypervisor.h>
52 #include <asm/fixmap.h>
53 #include <asm/processor.h>
54 #include <asm/proto.h>
55 #include <asm/msr-index.h>
56 #include <asm/traps.h>
57 #include <asm/setup.h>
58 #include <asm/desc.h>
59 #include <asm/pgalloc.h>
60 #include <asm/pgtable.h>
61 #include <asm/tlbflush.h>
62 #include <asm/reboot.h>
63 #include <asm/stackprotector.h>
64 #include <asm/hypervisor.h>
65 #include <asm/mwait.h>
66 #include <asm/pci_x86.h>
67 #include <asm/pat.h>
68
69 #ifdef CONFIG_ACPI
70 #include <linux/acpi.h>
71 #include <asm/acpi.h>
72 #include <acpi/pdc_intel.h>
73 #include <acpi/processor.h>
74 #include <xen/interface/platform.h>
75 #endif
76
77 #include "xen-ops.h"
78 #include "mmu.h"
79 #include "multicalls.h"
80
81 EXPORT_SYMBOL_GPL(hypercall_page);
82
83 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
84 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
85
86 enum xen_domain_type xen_domain_type = XEN_NATIVE;
87 EXPORT_SYMBOL_GPL(xen_domain_type);
88
89 unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START;
90 EXPORT_SYMBOL(machine_to_phys_mapping);
91 unsigned long machine_to_phys_nr;
92 EXPORT_SYMBOL(machine_to_phys_nr);
93
94 struct start_info *xen_start_info;
95 EXPORT_SYMBOL_GPL(xen_start_info);
96
97 struct shared_info xen_dummy_shared_info;
98
99 void *xen_initial_gdt;
100
101 RESERVE_BRK(shared_info_page_brk, PAGE_SIZE);
102 __read_mostly int xen_have_vector_callback;
103 EXPORT_SYMBOL_GPL(xen_have_vector_callback);
104
105 /*
106 * Point at some empty memory to start with. We map the real shared_info
107 * page as soon as fixmap is up and running.
108 */
109 struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
110
111 /*
112 * Flag to determine whether vcpu info placement is available on all
113 * VCPUs. We assume it is to start with, and then set it to zero on
114 * the first failure. This is because it can succeed on some VCPUs
115 * and not others, since it can involve hypervisor memory allocation,
116 * or because the guest failed to guarantee all the appropriate
117 * constraints on all VCPUs (ie buffer can't cross a page boundary).
118 *
119 * Note that any particular CPU may be using a placed vcpu structure,
120 * but we can only optimise if the all are.
121 *
122 * 0: not available, 1: available
123 */
124 static int have_vcpu_info_placement = 1;
125
clamp_max_cpus(void)126 static void clamp_max_cpus(void)
127 {
128 #ifdef CONFIG_SMP
129 if (setup_max_cpus > MAX_VIRT_CPUS)
130 setup_max_cpus = MAX_VIRT_CPUS;
131 #endif
132 }
133
xen_vcpu_setup(int cpu)134 static void xen_vcpu_setup(int cpu)
135 {
136 struct vcpu_register_vcpu_info info;
137 int err;
138 struct vcpu_info *vcpup;
139
140 BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
141
142 /*
143 * This path is called twice on PVHVM - first during bootup via
144 * smp_init -> xen_hvm_cpu_notify, and then if the VCPU is being
145 * hotplugged: cpu_up -> xen_hvm_cpu_notify.
146 * As we can only do the VCPUOP_register_vcpu_info once lets
147 * not over-write its result.
148 *
149 * For PV it is called during restore (xen_vcpu_restore) and bootup
150 * (xen_setup_vcpu_info_placement). The hotplug mechanism does not
151 * use this function.
152 */
153 if (xen_hvm_domain()) {
154 if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu))
155 return;
156 }
157 if (cpu < MAX_VIRT_CPUS)
158 per_cpu(xen_vcpu,cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
159
160 if (!have_vcpu_info_placement) {
161 if (cpu >= MAX_VIRT_CPUS)
162 clamp_max_cpus();
163 return;
164 }
165
166 vcpup = &per_cpu(xen_vcpu_info, cpu);
167 info.mfn = arbitrary_virt_to_mfn(vcpup);
168 info.offset = offset_in_page(vcpup);
169
170 /* Check to see if the hypervisor will put the vcpu_info
171 structure where we want it, which allows direct access via
172 a percpu-variable. */
173 err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
174
175 if (err) {
176 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
177 have_vcpu_info_placement = 0;
178 clamp_max_cpus();
179 } else {
180 /* This cpu is using the registered vcpu info, even if
181 later ones fail to. */
182 per_cpu(xen_vcpu, cpu) = vcpup;
183 }
184 }
185
186 /*
187 * On restore, set the vcpu placement up again.
188 * If it fails, then we're in a bad state, since
189 * we can't back out from using it...
190 */
xen_vcpu_restore(void)191 void xen_vcpu_restore(void)
192 {
193 int cpu;
194
195 for_each_online_cpu(cpu) {
196 bool other_cpu = (cpu != smp_processor_id());
197
198 if (other_cpu &&
199 HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL))
200 BUG();
201
202 xen_setup_runstate_info(cpu);
203
204 if (have_vcpu_info_placement)
205 xen_vcpu_setup(cpu);
206
207 if (other_cpu &&
208 HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
209 BUG();
210 }
211 }
212
xen_banner(void)213 static void __init xen_banner(void)
214 {
215 unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
216 struct xen_extraversion extra;
217 HYPERVISOR_xen_version(XENVER_extraversion, &extra);
218
219 printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
220 pv_info.name);
221 printk(KERN_INFO "Xen version: %d.%d%s%s\n",
222 version >> 16, version & 0xffff, extra.extraversion,
223 xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
224 }
225
226 #define CPUID_THERM_POWER_LEAF 6
227 #define APERFMPERF_PRESENT 0
228
229 static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
230 static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
231
232 static __read_mostly unsigned int cpuid_leaf1_ecx_set_mask;
233 static __read_mostly unsigned int cpuid_leaf5_ecx_val;
234 static __read_mostly unsigned int cpuid_leaf5_edx_val;
235
xen_cpuid(unsigned int * ax,unsigned int * bx,unsigned int * cx,unsigned int * dx)236 static void xen_cpuid(unsigned int *ax, unsigned int *bx,
237 unsigned int *cx, unsigned int *dx)
238 {
239 unsigned maskebx = ~0;
240 unsigned maskecx = ~0;
241 unsigned maskedx = ~0;
242 unsigned setecx = 0;
243 /*
244 * Mask out inconvenient features, to try and disable as many
245 * unsupported kernel subsystems as possible.
246 */
247 switch (*ax) {
248 case 1:
249 maskecx = cpuid_leaf1_ecx_mask;
250 setecx = cpuid_leaf1_ecx_set_mask;
251 maskedx = cpuid_leaf1_edx_mask;
252 break;
253
254 case CPUID_MWAIT_LEAF:
255 /* Synthesize the values.. */
256 *ax = 0;
257 *bx = 0;
258 *cx = cpuid_leaf5_ecx_val;
259 *dx = cpuid_leaf5_edx_val;
260 return;
261
262 case CPUID_THERM_POWER_LEAF:
263 /* Disabling APERFMPERF for kernel usage */
264 maskecx = ~(1 << APERFMPERF_PRESENT);
265 break;
266
267 case 0xb:
268 /* Suppress extended topology stuff */
269 maskebx = 0;
270 break;
271 }
272
273 asm(XEN_EMULATE_PREFIX "cpuid"
274 : "=a" (*ax),
275 "=b" (*bx),
276 "=c" (*cx),
277 "=d" (*dx)
278 : "0" (*ax), "2" (*cx));
279
280 *bx &= maskebx;
281 *cx &= maskecx;
282 *cx |= setecx;
283 *dx &= maskedx;
284
285 }
286
xen_check_mwait(void)287 static bool __init xen_check_mwait(void)
288 {
289 #if defined(CONFIG_ACPI) && !defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR) && \
290 !defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR_MODULE)
291 struct xen_platform_op op = {
292 .cmd = XENPF_set_processor_pminfo,
293 .u.set_pminfo.id = -1,
294 .u.set_pminfo.type = XEN_PM_PDC,
295 };
296 uint32_t buf[3];
297 unsigned int ax, bx, cx, dx;
298 unsigned int mwait_mask;
299
300 /* We need to determine whether it is OK to expose the MWAIT
301 * capability to the kernel to harvest deeper than C3 states from ACPI
302 * _CST using the processor_harvest_xen.c module. For this to work, we
303 * need to gather the MWAIT_LEAF values (which the cstate.c code
304 * checks against). The hypervisor won't expose the MWAIT flag because
305 * it would break backwards compatibility; so we will find out directly
306 * from the hardware and hypercall.
307 */
308 if (!xen_initial_domain())
309 return false;
310
311 ax = 1;
312 cx = 0;
313
314 native_cpuid(&ax, &bx, &cx, &dx);
315
316 mwait_mask = (1 << (X86_FEATURE_EST % 32)) |
317 (1 << (X86_FEATURE_MWAIT % 32));
318
319 if ((cx & mwait_mask) != mwait_mask)
320 return false;
321
322 /* We need to emulate the MWAIT_LEAF and for that we need both
323 * ecx and edx. The hypercall provides only partial information.
324 */
325
326 ax = CPUID_MWAIT_LEAF;
327 bx = 0;
328 cx = 0;
329 dx = 0;
330
331 native_cpuid(&ax, &bx, &cx, &dx);
332
333 /* Ask the Hypervisor whether to clear ACPI_PDC_C_C2C3_FFH. If so,
334 * don't expose MWAIT_LEAF and let ACPI pick the IOPORT version of C3.
335 */
336 buf[0] = ACPI_PDC_REVISION_ID;
337 buf[1] = 1;
338 buf[2] = (ACPI_PDC_C_CAPABILITY_SMP | ACPI_PDC_EST_CAPABILITY_SWSMP);
339
340 set_xen_guest_handle(op.u.set_pminfo.pdc, buf);
341
342 if ((HYPERVISOR_dom0_op(&op) == 0) &&
343 (buf[2] & (ACPI_PDC_C_C1_FFH | ACPI_PDC_C_C2C3_FFH))) {
344 cpuid_leaf5_ecx_val = cx;
345 cpuid_leaf5_edx_val = dx;
346 }
347 return true;
348 #else
349 return false;
350 #endif
351 }
xen_init_cpuid_mask(void)352 static void __init xen_init_cpuid_mask(void)
353 {
354 unsigned int ax, bx, cx, dx;
355 unsigned int xsave_mask;
356
357 cpuid_leaf1_edx_mask =
358 ~((1 << X86_FEATURE_MCE) | /* disable MCE */
359 (1 << X86_FEATURE_MCA) | /* disable MCA */
360 (1 << X86_FEATURE_MTRR) | /* disable MTRR */
361 (1 << X86_FEATURE_ACC)); /* thermal monitoring */
362
363 if (!xen_initial_domain())
364 cpuid_leaf1_edx_mask &=
365 ~((1 << X86_FEATURE_APIC) | /* disable local APIC */
366 (1 << X86_FEATURE_ACPI)); /* disable ACPI */
367 ax = 1;
368 cx = 0;
369 xen_cpuid(&ax, &bx, &cx, &dx);
370
371 xsave_mask =
372 (1 << (X86_FEATURE_XSAVE % 32)) |
373 (1 << (X86_FEATURE_OSXSAVE % 32));
374
375 /* Xen will set CR4.OSXSAVE if supported and not disabled by force */
376 if ((cx & xsave_mask) != xsave_mask)
377 cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */
378 if (xen_check_mwait())
379 cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32));
380 }
381
xen_set_debugreg(int reg,unsigned long val)382 static void xen_set_debugreg(int reg, unsigned long val)
383 {
384 HYPERVISOR_set_debugreg(reg, val);
385 }
386
xen_get_debugreg(int reg)387 static unsigned long xen_get_debugreg(int reg)
388 {
389 return HYPERVISOR_get_debugreg(reg);
390 }
391
xen_end_context_switch(struct task_struct * next)392 static void xen_end_context_switch(struct task_struct *next)
393 {
394 xen_mc_flush();
395 paravirt_end_context_switch(next);
396 }
397
xen_store_tr(void)398 static unsigned long xen_store_tr(void)
399 {
400 return 0;
401 }
402
403 /*
404 * Set the page permissions for a particular virtual address. If the
405 * address is a vmalloc mapping (or other non-linear mapping), then
406 * find the linear mapping of the page and also set its protections to
407 * match.
408 */
set_aliased_prot(void * v,pgprot_t prot)409 static void set_aliased_prot(void *v, pgprot_t prot)
410 {
411 int level;
412 pte_t *ptep;
413 pte_t pte;
414 unsigned long pfn;
415 struct page *page;
416
417 ptep = lookup_address((unsigned long)v, &level);
418 BUG_ON(ptep == NULL);
419
420 pfn = pte_pfn(*ptep);
421 page = pfn_to_page(pfn);
422
423 pte = pfn_pte(pfn, prot);
424
425 if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
426 BUG();
427
428 if (!PageHighMem(page)) {
429 void *av = __va(PFN_PHYS(pfn));
430
431 if (av != v)
432 if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
433 BUG();
434 } else
435 kmap_flush_unused();
436 }
437
xen_alloc_ldt(struct desc_struct * ldt,unsigned entries)438 static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
439 {
440 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
441 int i;
442
443 for(i = 0; i < entries; i += entries_per_page)
444 set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
445 }
446
xen_free_ldt(struct desc_struct * ldt,unsigned entries)447 static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
448 {
449 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
450 int i;
451
452 for(i = 0; i < entries; i += entries_per_page)
453 set_aliased_prot(ldt + i, PAGE_KERNEL);
454 }
455
xen_set_ldt(const void * addr,unsigned entries)456 static void xen_set_ldt(const void *addr, unsigned entries)
457 {
458 struct mmuext_op *op;
459 struct multicall_space mcs = xen_mc_entry(sizeof(*op));
460
461 trace_xen_cpu_set_ldt(addr, entries);
462
463 op = mcs.args;
464 op->cmd = MMUEXT_SET_LDT;
465 op->arg1.linear_addr = (unsigned long)addr;
466 op->arg2.nr_ents = entries;
467
468 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
469
470 xen_mc_issue(PARAVIRT_LAZY_CPU);
471 }
472
xen_load_gdt(const struct desc_ptr * dtr)473 static void xen_load_gdt(const struct desc_ptr *dtr)
474 {
475 unsigned long va = dtr->address;
476 unsigned int size = dtr->size + 1;
477 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
478 unsigned long frames[pages];
479 int f;
480
481 /*
482 * A GDT can be up to 64k in size, which corresponds to 8192
483 * 8-byte entries, or 16 4k pages..
484 */
485
486 BUG_ON(size > 65536);
487 BUG_ON(va & ~PAGE_MASK);
488
489 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
490 int level;
491 pte_t *ptep;
492 unsigned long pfn, mfn;
493 void *virt;
494
495 /*
496 * The GDT is per-cpu and is in the percpu data area.
497 * That can be virtually mapped, so we need to do a
498 * page-walk to get the underlying MFN for the
499 * hypercall. The page can also be in the kernel's
500 * linear range, so we need to RO that mapping too.
501 */
502 ptep = lookup_address(va, &level);
503 BUG_ON(ptep == NULL);
504
505 pfn = pte_pfn(*ptep);
506 mfn = pfn_to_mfn(pfn);
507 virt = __va(PFN_PHYS(pfn));
508
509 frames[f] = mfn;
510
511 make_lowmem_page_readonly((void *)va);
512 make_lowmem_page_readonly(virt);
513 }
514
515 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
516 BUG();
517 }
518
519 /*
520 * load_gdt for early boot, when the gdt is only mapped once
521 */
xen_load_gdt_boot(const struct desc_ptr * dtr)522 static void __init xen_load_gdt_boot(const struct desc_ptr *dtr)
523 {
524 unsigned long va = dtr->address;
525 unsigned int size = dtr->size + 1;
526 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
527 unsigned long frames[pages];
528 int f;
529
530 /*
531 * A GDT can be up to 64k in size, which corresponds to 8192
532 * 8-byte entries, or 16 4k pages..
533 */
534
535 BUG_ON(size > 65536);
536 BUG_ON(va & ~PAGE_MASK);
537
538 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
539 pte_t pte;
540 unsigned long pfn, mfn;
541
542 pfn = virt_to_pfn(va);
543 mfn = pfn_to_mfn(pfn);
544
545 pte = pfn_pte(pfn, PAGE_KERNEL_RO);
546
547 if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0))
548 BUG();
549
550 frames[f] = mfn;
551 }
552
553 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
554 BUG();
555 }
556
load_TLS_descriptor(struct thread_struct * t,unsigned int cpu,unsigned int i)557 static void load_TLS_descriptor(struct thread_struct *t,
558 unsigned int cpu, unsigned int i)
559 {
560 struct desc_struct *gdt = get_cpu_gdt_table(cpu);
561 xmaddr_t maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
562 struct multicall_space mc = __xen_mc_entry(0);
563
564 MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
565 }
566
xen_load_tls(struct thread_struct * t,unsigned int cpu)567 static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
568 {
569 /*
570 * XXX sleazy hack: If we're being called in a lazy-cpu zone
571 * and lazy gs handling is enabled, it means we're in a
572 * context switch, and %gs has just been saved. This means we
573 * can zero it out to prevent faults on exit from the
574 * hypervisor if the next process has no %gs. Either way, it
575 * has been saved, and the new value will get loaded properly.
576 * This will go away as soon as Xen has been modified to not
577 * save/restore %gs for normal hypercalls.
578 *
579 * On x86_64, this hack is not used for %gs, because gs points
580 * to KERNEL_GS_BASE (and uses it for PDA references), so we
581 * must not zero %gs on x86_64
582 *
583 * For x86_64, we need to zero %fs, otherwise we may get an
584 * exception between the new %fs descriptor being loaded and
585 * %fs being effectively cleared at __switch_to().
586 */
587 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
588 #ifdef CONFIG_X86_32
589 lazy_load_gs(0);
590 #else
591 loadsegment(fs, 0);
592 #endif
593 }
594
595 xen_mc_batch();
596
597 load_TLS_descriptor(t, cpu, 0);
598 load_TLS_descriptor(t, cpu, 1);
599 load_TLS_descriptor(t, cpu, 2);
600
601 xen_mc_issue(PARAVIRT_LAZY_CPU);
602 }
603
604 #ifdef CONFIG_X86_64
xen_load_gs_index(unsigned int idx)605 static void xen_load_gs_index(unsigned int idx)
606 {
607 if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
608 BUG();
609 }
610 #endif
611
xen_write_ldt_entry(struct desc_struct * dt,int entrynum,const void * ptr)612 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
613 const void *ptr)
614 {
615 xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
616 u64 entry = *(u64 *)ptr;
617
618 trace_xen_cpu_write_ldt_entry(dt, entrynum, entry);
619
620 preempt_disable();
621
622 xen_mc_flush();
623 if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
624 BUG();
625
626 preempt_enable();
627 }
628
cvt_gate_to_trap(int vector,const gate_desc * val,struct trap_info * info)629 static int cvt_gate_to_trap(int vector, const gate_desc *val,
630 struct trap_info *info)
631 {
632 unsigned long addr;
633
634 if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT)
635 return 0;
636
637 info->vector = vector;
638
639 addr = gate_offset(*val);
640 #ifdef CONFIG_X86_64
641 /*
642 * Look for known traps using IST, and substitute them
643 * appropriately. The debugger ones are the only ones we care
644 * about. Xen will handle faults like double_fault and
645 * machine_check, so we should never see them. Warn if
646 * there's an unexpected IST-using fault handler.
647 */
648 if (addr == (unsigned long)debug)
649 addr = (unsigned long)xen_debug;
650 else if (addr == (unsigned long)int3)
651 addr = (unsigned long)xen_int3;
652 else if (addr == (unsigned long)stack_segment)
653 addr = (unsigned long)xen_stack_segment;
654 else if (addr == (unsigned long)double_fault ||
655 addr == (unsigned long)nmi) {
656 /* Don't need to handle these */
657 return 0;
658 #ifdef CONFIG_X86_MCE
659 } else if (addr == (unsigned long)machine_check) {
660 return 0;
661 #endif
662 } else {
663 /* Some other trap using IST? */
664 if (WARN_ON(val->ist != 0))
665 return 0;
666 }
667 #endif /* CONFIG_X86_64 */
668 info->address = addr;
669
670 info->cs = gate_segment(*val);
671 info->flags = val->dpl;
672 /* interrupt gates clear IF */
673 if (val->type == GATE_INTERRUPT)
674 info->flags |= 1 << 2;
675
676 return 1;
677 }
678
679 /* Locations of each CPU's IDT */
680 static DEFINE_PER_CPU(struct desc_ptr, idt_desc);
681
682 /* Set an IDT entry. If the entry is part of the current IDT, then
683 also update Xen. */
xen_write_idt_entry(gate_desc * dt,int entrynum,const gate_desc * g)684 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
685 {
686 unsigned long p = (unsigned long)&dt[entrynum];
687 unsigned long start, end;
688
689 trace_xen_cpu_write_idt_entry(dt, entrynum, g);
690
691 preempt_disable();
692
693 start = __this_cpu_read(idt_desc.address);
694 end = start + __this_cpu_read(idt_desc.size) + 1;
695
696 xen_mc_flush();
697
698 native_write_idt_entry(dt, entrynum, g);
699
700 if (p >= start && (p + 8) <= end) {
701 struct trap_info info[2];
702
703 info[1].address = 0;
704
705 if (cvt_gate_to_trap(entrynum, g, &info[0]))
706 if (HYPERVISOR_set_trap_table(info))
707 BUG();
708 }
709
710 preempt_enable();
711 }
712
xen_convert_trap_info(const struct desc_ptr * desc,struct trap_info * traps)713 static void xen_convert_trap_info(const struct desc_ptr *desc,
714 struct trap_info *traps)
715 {
716 unsigned in, out, count;
717
718 count = (desc->size+1) / sizeof(gate_desc);
719 BUG_ON(count > 256);
720
721 for (in = out = 0; in < count; in++) {
722 gate_desc *entry = (gate_desc*)(desc->address) + in;
723
724 if (cvt_gate_to_trap(in, entry, &traps[out]))
725 out++;
726 }
727 traps[out].address = 0;
728 }
729
xen_copy_trap_info(struct trap_info * traps)730 void xen_copy_trap_info(struct trap_info *traps)
731 {
732 const struct desc_ptr *desc = &__get_cpu_var(idt_desc);
733
734 xen_convert_trap_info(desc, traps);
735 }
736
737 /* Load a new IDT into Xen. In principle this can be per-CPU, so we
738 hold a spinlock to protect the static traps[] array (static because
739 it avoids allocation, and saves stack space). */
xen_load_idt(const struct desc_ptr * desc)740 static void xen_load_idt(const struct desc_ptr *desc)
741 {
742 static DEFINE_SPINLOCK(lock);
743 static struct trap_info traps[257];
744
745 trace_xen_cpu_load_idt(desc);
746
747 spin_lock(&lock);
748
749 __get_cpu_var(idt_desc) = *desc;
750
751 xen_convert_trap_info(desc, traps);
752
753 xen_mc_flush();
754 if (HYPERVISOR_set_trap_table(traps))
755 BUG();
756
757 spin_unlock(&lock);
758 }
759
760 /* Write a GDT descriptor entry. Ignore LDT descriptors, since
761 they're handled differently. */
xen_write_gdt_entry(struct desc_struct * dt,int entry,const void * desc,int type)762 static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
763 const void *desc, int type)
764 {
765 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
766
767 preempt_disable();
768
769 switch (type) {
770 case DESC_LDT:
771 case DESC_TSS:
772 /* ignore */
773 break;
774
775 default: {
776 xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]);
777
778 xen_mc_flush();
779 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
780 BUG();
781 }
782
783 }
784
785 preempt_enable();
786 }
787
788 /*
789 * Version of write_gdt_entry for use at early boot-time needed to
790 * update an entry as simply as possible.
791 */
xen_write_gdt_entry_boot(struct desc_struct * dt,int entry,const void * desc,int type)792 static void __init xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
793 const void *desc, int type)
794 {
795 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
796
797 switch (type) {
798 case DESC_LDT:
799 case DESC_TSS:
800 /* ignore */
801 break;
802
803 default: {
804 xmaddr_t maddr = virt_to_machine(&dt[entry]);
805
806 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
807 dt[entry] = *(struct desc_struct *)desc;
808 }
809
810 }
811 }
812
xen_load_sp0(struct tss_struct * tss,struct thread_struct * thread)813 static void xen_load_sp0(struct tss_struct *tss,
814 struct thread_struct *thread)
815 {
816 struct multicall_space mcs;
817
818 mcs = xen_mc_entry(0);
819 MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
820 xen_mc_issue(PARAVIRT_LAZY_CPU);
821 }
822
xen_set_iopl_mask(unsigned mask)823 static void xen_set_iopl_mask(unsigned mask)
824 {
825 struct physdev_set_iopl set_iopl;
826
827 /* Force the change at ring 0. */
828 set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
829 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
830 }
831
xen_io_delay(void)832 static void xen_io_delay(void)
833 {
834 }
835
836 #ifdef CONFIG_X86_LOCAL_APIC
xen_set_apic_id(unsigned int x)837 static unsigned long xen_set_apic_id(unsigned int x)
838 {
839 WARN_ON(1);
840 return x;
841 }
xen_get_apic_id(unsigned long x)842 static unsigned int xen_get_apic_id(unsigned long x)
843 {
844 return ((x)>>24) & 0xFFu;
845 }
xen_apic_read(u32 reg)846 static u32 xen_apic_read(u32 reg)
847 {
848 struct xen_platform_op op = {
849 .cmd = XENPF_get_cpuinfo,
850 .interface_version = XENPF_INTERFACE_VERSION,
851 .u.pcpu_info.xen_cpuid = 0,
852 };
853 int ret = 0;
854
855 /* Shouldn't need this as APIC is turned off for PV, and we only
856 * get called on the bootup processor. But just in case. */
857 if (!xen_initial_domain() || smp_processor_id())
858 return 0;
859
860 if (reg == APIC_LVR)
861 return 0x10;
862
863 if (reg != APIC_ID)
864 return 0;
865
866 ret = HYPERVISOR_dom0_op(&op);
867 if (ret)
868 return 0;
869
870 return op.u.pcpu_info.apic_id << 24;
871 }
872
xen_apic_write(u32 reg,u32 val)873 static void xen_apic_write(u32 reg, u32 val)
874 {
875 /* Warn to see if there's any stray references */
876 WARN_ON(1);
877 }
878
xen_apic_icr_read(void)879 static u64 xen_apic_icr_read(void)
880 {
881 return 0;
882 }
883
xen_apic_icr_write(u32 low,u32 id)884 static void xen_apic_icr_write(u32 low, u32 id)
885 {
886 /* Warn to see if there's any stray references */
887 WARN_ON(1);
888 }
889
xen_apic_wait_icr_idle(void)890 static void xen_apic_wait_icr_idle(void)
891 {
892 return;
893 }
894
xen_safe_apic_wait_icr_idle(void)895 static u32 xen_safe_apic_wait_icr_idle(void)
896 {
897 return 0;
898 }
899
set_xen_basic_apic_ops(void)900 static void set_xen_basic_apic_ops(void)
901 {
902 apic->read = xen_apic_read;
903 apic->write = xen_apic_write;
904 apic->icr_read = xen_apic_icr_read;
905 apic->icr_write = xen_apic_icr_write;
906 apic->wait_icr_idle = xen_apic_wait_icr_idle;
907 apic->safe_wait_icr_idle = xen_safe_apic_wait_icr_idle;
908 apic->set_apic_id = xen_set_apic_id;
909 apic->get_apic_id = xen_get_apic_id;
910 }
911
912 #endif
913
xen_clts(void)914 static void xen_clts(void)
915 {
916 struct multicall_space mcs;
917
918 mcs = xen_mc_entry(0);
919
920 MULTI_fpu_taskswitch(mcs.mc, 0);
921
922 xen_mc_issue(PARAVIRT_LAZY_CPU);
923 }
924
925 static DEFINE_PER_CPU(unsigned long, xen_cr0_value);
926
xen_read_cr0(void)927 static unsigned long xen_read_cr0(void)
928 {
929 unsigned long cr0 = this_cpu_read(xen_cr0_value);
930
931 if (unlikely(cr0 == 0)) {
932 cr0 = native_read_cr0();
933 this_cpu_write(xen_cr0_value, cr0);
934 }
935
936 return cr0;
937 }
938
xen_write_cr0(unsigned long cr0)939 static void xen_write_cr0(unsigned long cr0)
940 {
941 struct multicall_space mcs;
942
943 this_cpu_write(xen_cr0_value, cr0);
944
945 /* Only pay attention to cr0.TS; everything else is
946 ignored. */
947 mcs = xen_mc_entry(0);
948
949 MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
950
951 xen_mc_issue(PARAVIRT_LAZY_CPU);
952 }
953
xen_write_cr4(unsigned long cr4)954 static void xen_write_cr4(unsigned long cr4)
955 {
956 cr4 &= ~X86_CR4_PGE;
957 cr4 &= ~X86_CR4_PSE;
958
959 native_write_cr4(cr4);
960 }
961 #ifdef CONFIG_X86_64
xen_read_cr8(void)962 static inline unsigned long xen_read_cr8(void)
963 {
964 return 0;
965 }
xen_write_cr8(unsigned long val)966 static inline void xen_write_cr8(unsigned long val)
967 {
968 BUG_ON(val);
969 }
970 #endif
xen_write_msr_safe(unsigned int msr,unsigned low,unsigned high)971 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
972 {
973 int ret;
974
975 ret = 0;
976
977 switch (msr) {
978 #ifdef CONFIG_X86_64
979 unsigned which;
980 u64 base;
981
982 case MSR_FS_BASE: which = SEGBASE_FS; goto set;
983 case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set;
984 case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set;
985
986 set:
987 base = ((u64)high << 32) | low;
988 if (HYPERVISOR_set_segment_base(which, base) != 0)
989 ret = -EIO;
990 break;
991 #endif
992
993 case MSR_STAR:
994 case MSR_CSTAR:
995 case MSR_LSTAR:
996 case MSR_SYSCALL_MASK:
997 case MSR_IA32_SYSENTER_CS:
998 case MSR_IA32_SYSENTER_ESP:
999 case MSR_IA32_SYSENTER_EIP:
1000 /* Fast syscall setup is all done in hypercalls, so
1001 these are all ignored. Stub them out here to stop
1002 Xen console noise. */
1003 break;
1004
1005 case MSR_IA32_CR_PAT:
1006 if (smp_processor_id() == 0)
1007 xen_set_pat(((u64)high << 32) | low);
1008 break;
1009
1010 default:
1011 ret = native_write_msr_safe(msr, low, high);
1012 }
1013
1014 return ret;
1015 }
1016
xen_setup_shared_info(void)1017 void xen_setup_shared_info(void)
1018 {
1019 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1020 set_fixmap(FIX_PARAVIRT_BOOTMAP,
1021 xen_start_info->shared_info);
1022
1023 HYPERVISOR_shared_info =
1024 (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
1025 } else
1026 HYPERVISOR_shared_info =
1027 (struct shared_info *)__va(xen_start_info->shared_info);
1028
1029 #ifndef CONFIG_SMP
1030 /* In UP this is as good a place as any to set up shared info */
1031 xen_setup_vcpu_info_placement();
1032 #endif
1033
1034 xen_setup_mfn_list_list();
1035 }
1036
1037 /* This is called once we have the cpu_possible_mask */
xen_setup_vcpu_info_placement(void)1038 void xen_setup_vcpu_info_placement(void)
1039 {
1040 int cpu;
1041
1042 for_each_possible_cpu(cpu)
1043 xen_vcpu_setup(cpu);
1044
1045 /* xen_vcpu_setup managed to place the vcpu_info within the
1046 percpu area for all cpus, so make use of it */
1047 if (have_vcpu_info_placement) {
1048 pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
1049 pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct);
1050 pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
1051 pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
1052 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
1053 }
1054 }
1055
xen_patch(u8 type,u16 clobbers,void * insnbuf,unsigned long addr,unsigned len)1056 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
1057 unsigned long addr, unsigned len)
1058 {
1059 char *start, *end, *reloc;
1060 unsigned ret;
1061
1062 start = end = reloc = NULL;
1063
1064 #define SITE(op, x) \
1065 case PARAVIRT_PATCH(op.x): \
1066 if (have_vcpu_info_placement) { \
1067 start = (char *)xen_##x##_direct; \
1068 end = xen_##x##_direct_end; \
1069 reloc = xen_##x##_direct_reloc; \
1070 } \
1071 goto patch_site
1072
1073 switch (type) {
1074 SITE(pv_irq_ops, irq_enable);
1075 SITE(pv_irq_ops, irq_disable);
1076 SITE(pv_irq_ops, save_fl);
1077 SITE(pv_irq_ops, restore_fl);
1078 #undef SITE
1079
1080 patch_site:
1081 if (start == NULL || (end-start) > len)
1082 goto default_patch;
1083
1084 ret = paravirt_patch_insns(insnbuf, len, start, end);
1085
1086 /* Note: because reloc is assigned from something that
1087 appears to be an array, gcc assumes it's non-null,
1088 but doesn't know its relationship with start and
1089 end. */
1090 if (reloc > start && reloc < end) {
1091 int reloc_off = reloc - start;
1092 long *relocp = (long *)(insnbuf + reloc_off);
1093 long delta = start - (char *)addr;
1094
1095 *relocp += delta;
1096 }
1097 break;
1098
1099 default_patch:
1100 default:
1101 ret = paravirt_patch_default(type, clobbers, insnbuf,
1102 addr, len);
1103 break;
1104 }
1105
1106 return ret;
1107 }
1108
1109 static const struct pv_info xen_info __initconst = {
1110 .paravirt_enabled = 1,
1111 .shared_kernel_pmd = 0,
1112
1113 #ifdef CONFIG_X86_64
1114 .extra_user_64bit_cs = FLAT_USER_CS64,
1115 #endif
1116
1117 .name = "Xen",
1118 };
1119
1120 static const struct pv_init_ops xen_init_ops __initconst = {
1121 .patch = xen_patch,
1122 };
1123
1124 static const struct pv_cpu_ops xen_cpu_ops __initconst = {
1125 .cpuid = xen_cpuid,
1126
1127 .set_debugreg = xen_set_debugreg,
1128 .get_debugreg = xen_get_debugreg,
1129
1130 .clts = xen_clts,
1131
1132 .read_cr0 = xen_read_cr0,
1133 .write_cr0 = xen_write_cr0,
1134
1135 .read_cr4 = native_read_cr4,
1136 .read_cr4_safe = native_read_cr4_safe,
1137 .write_cr4 = xen_write_cr4,
1138
1139 #ifdef CONFIG_X86_64
1140 .read_cr8 = xen_read_cr8,
1141 .write_cr8 = xen_write_cr8,
1142 #endif
1143
1144 .wbinvd = native_wbinvd,
1145
1146 .read_msr = native_read_msr_safe,
1147 .rdmsr_regs = native_rdmsr_safe_regs,
1148 .write_msr = xen_write_msr_safe,
1149 .wrmsr_regs = native_wrmsr_safe_regs,
1150
1151 .read_tsc = native_read_tsc,
1152 .read_pmc = native_read_pmc,
1153
1154 .read_tscp = native_read_tscp,
1155
1156 .iret = xen_iret,
1157 .irq_enable_sysexit = xen_sysexit,
1158 #ifdef CONFIG_X86_64
1159 .usergs_sysret32 = xen_sysret32,
1160 .usergs_sysret64 = xen_sysret64,
1161 #endif
1162
1163 .load_tr_desc = paravirt_nop,
1164 .set_ldt = xen_set_ldt,
1165 .load_gdt = xen_load_gdt,
1166 .load_idt = xen_load_idt,
1167 .load_tls = xen_load_tls,
1168 #ifdef CONFIG_X86_64
1169 .load_gs_index = xen_load_gs_index,
1170 #endif
1171
1172 .alloc_ldt = xen_alloc_ldt,
1173 .free_ldt = xen_free_ldt,
1174
1175 .store_gdt = native_store_gdt,
1176 .store_idt = native_store_idt,
1177 .store_tr = xen_store_tr,
1178
1179 .write_ldt_entry = xen_write_ldt_entry,
1180 .write_gdt_entry = xen_write_gdt_entry,
1181 .write_idt_entry = xen_write_idt_entry,
1182 .load_sp0 = xen_load_sp0,
1183
1184 .set_iopl_mask = xen_set_iopl_mask,
1185 .io_delay = xen_io_delay,
1186
1187 /* Xen takes care of %gs when switching to usermode for us */
1188 .swapgs = paravirt_nop,
1189
1190 .start_context_switch = paravirt_start_context_switch,
1191 .end_context_switch = xen_end_context_switch,
1192 };
1193
1194 static const struct pv_apic_ops xen_apic_ops __initconst = {
1195 #ifdef CONFIG_X86_LOCAL_APIC
1196 .startup_ipi_hook = paravirt_nop,
1197 #endif
1198 };
1199
xen_reboot(int reason)1200 static void xen_reboot(int reason)
1201 {
1202 struct sched_shutdown r = { .reason = reason };
1203
1204 if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
1205 BUG();
1206 }
1207
xen_restart(char * msg)1208 static void xen_restart(char *msg)
1209 {
1210 xen_reboot(SHUTDOWN_reboot);
1211 }
1212
xen_emergency_restart(void)1213 static void xen_emergency_restart(void)
1214 {
1215 xen_reboot(SHUTDOWN_reboot);
1216 }
1217
xen_machine_halt(void)1218 static void xen_machine_halt(void)
1219 {
1220 xen_reboot(SHUTDOWN_poweroff);
1221 }
1222
xen_machine_power_off(void)1223 static void xen_machine_power_off(void)
1224 {
1225 if (pm_power_off)
1226 pm_power_off();
1227 xen_reboot(SHUTDOWN_poweroff);
1228 }
1229
xen_crash_shutdown(struct pt_regs * regs)1230 static void xen_crash_shutdown(struct pt_regs *regs)
1231 {
1232 xen_reboot(SHUTDOWN_crash);
1233 }
1234
1235 static int
xen_panic_event(struct notifier_block * this,unsigned long event,void * ptr)1236 xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
1237 {
1238 xen_reboot(SHUTDOWN_crash);
1239 return NOTIFY_DONE;
1240 }
1241
1242 static struct notifier_block xen_panic_block = {
1243 .notifier_call= xen_panic_event,
1244 };
1245
xen_panic_handler_init(void)1246 int xen_panic_handler_init(void)
1247 {
1248 atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block);
1249 return 0;
1250 }
1251
1252 static const struct machine_ops xen_machine_ops __initconst = {
1253 .restart = xen_restart,
1254 .halt = xen_machine_halt,
1255 .power_off = xen_machine_power_off,
1256 .shutdown = xen_machine_halt,
1257 .crash_shutdown = xen_crash_shutdown,
1258 .emergency_restart = xen_emergency_restart,
1259 };
1260
1261 /*
1262 * Set up the GDT and segment registers for -fstack-protector. Until
1263 * we do this, we have to be careful not to call any stack-protected
1264 * function, which is most of the kernel.
1265 */
xen_setup_stackprotector(void)1266 static void __init xen_setup_stackprotector(void)
1267 {
1268 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
1269 pv_cpu_ops.load_gdt = xen_load_gdt_boot;
1270
1271 setup_stack_canary_segment(0);
1272 switch_to_new_gdt(0);
1273
1274 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry;
1275 pv_cpu_ops.load_gdt = xen_load_gdt;
1276 }
1277
1278 /* First C function to be called on Xen boot */
xen_start_kernel(void)1279 asmlinkage void __init xen_start_kernel(void)
1280 {
1281 struct physdev_set_iopl set_iopl;
1282 int rc;
1283 pgd_t *pgd;
1284
1285 if (!xen_start_info)
1286 return;
1287
1288 xen_domain_type = XEN_PV_DOMAIN;
1289
1290 xen_setup_machphys_mapping();
1291
1292 /* Install Xen paravirt ops */
1293 pv_info = xen_info;
1294 pv_init_ops = xen_init_ops;
1295 pv_cpu_ops = xen_cpu_ops;
1296 pv_apic_ops = xen_apic_ops;
1297
1298 x86_init.resources.memory_setup = xen_memory_setup;
1299 x86_init.oem.arch_setup = xen_arch_setup;
1300 x86_init.oem.banner = xen_banner;
1301
1302 xen_init_time_ops();
1303
1304 /*
1305 * Set up some pagetable state before starting to set any ptes.
1306 */
1307
1308 xen_init_mmu_ops();
1309
1310 /* Prevent unwanted bits from being set in PTEs. */
1311 __supported_pte_mask &= ~_PAGE_GLOBAL;
1312 #if 0
1313 if (!xen_initial_domain())
1314 #endif
1315 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
1316
1317 __supported_pte_mask |= _PAGE_IOMAP;
1318
1319 /*
1320 * Prevent page tables from being allocated in highmem, even
1321 * if CONFIG_HIGHPTE is enabled.
1322 */
1323 __userpte_alloc_gfp &= ~__GFP_HIGHMEM;
1324
1325 /* Work out if we support NX */
1326 x86_configure_nx();
1327
1328 xen_setup_features();
1329
1330 /* Get mfn list */
1331 if (!xen_feature(XENFEAT_auto_translated_physmap))
1332 xen_build_dynamic_phys_to_machine();
1333
1334 /*
1335 * Set up kernel GDT and segment registers, mainly so that
1336 * -fstack-protector code can be executed.
1337 */
1338 xen_setup_stackprotector();
1339
1340 xen_init_irq_ops();
1341 xen_init_cpuid_mask();
1342
1343 #ifdef CONFIG_X86_LOCAL_APIC
1344 /*
1345 * set up the basic apic ops.
1346 */
1347 set_xen_basic_apic_ops();
1348 #endif
1349
1350 if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
1351 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
1352 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
1353 }
1354
1355 machine_ops = xen_machine_ops;
1356
1357 /*
1358 * The only reliable way to retain the initial address of the
1359 * percpu gdt_page is to remember it here, so we can go and
1360 * mark it RW later, when the initial percpu area is freed.
1361 */
1362 xen_initial_gdt = &per_cpu(gdt_page, 0);
1363
1364 xen_smp_init();
1365
1366 #ifdef CONFIG_ACPI_NUMA
1367 /*
1368 * The pages we from Xen are not related to machine pages, so
1369 * any NUMA information the kernel tries to get from ACPI will
1370 * be meaningless. Prevent it from trying.
1371 */
1372 acpi_numa = -1;
1373 #endif
1374 #ifdef CONFIG_X86_PAT
1375 /*
1376 * For right now disable the PAT. We should remove this once
1377 * git commit 8eaffa67b43e99ae581622c5133e20b0f48bcef1
1378 * (xen/pat: Disable PAT support for now) is reverted.
1379 */
1380 pat_enabled = 0;
1381 #endif
1382 pgd = (pgd_t *)xen_start_info->pt_base;
1383
1384 /* Don't do the full vcpu_info placement stuff until we have a
1385 possible map and a non-dummy shared_info. */
1386 per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1387
1388 local_irq_disable();
1389 early_boot_irqs_disabled = true;
1390
1391 xen_raw_console_write("mapping kernel into physical memory\n");
1392 pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages);
1393 xen_ident_map_ISA();
1394
1395 /* Allocate and initialize top and mid mfn levels for p2m structure */
1396 xen_build_mfn_list_list();
1397
1398 /* keep using Xen gdt for now; no urgent need to change it */
1399
1400 #ifdef CONFIG_X86_32
1401 pv_info.kernel_rpl = 1;
1402 if (xen_feature(XENFEAT_supervisor_mode_kernel))
1403 pv_info.kernel_rpl = 0;
1404 #else
1405 pv_info.kernel_rpl = 0;
1406 #endif
1407 /* set the limit of our address space */
1408 xen_reserve_top();
1409
1410 /* We used to do this in xen_arch_setup, but that is too late on AMD
1411 * were early_cpu_init (run before ->arch_setup()) calls early_amd_init
1412 * which pokes 0xcf8 port.
1413 */
1414 set_iopl.iopl = 1;
1415 rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
1416 if (rc != 0)
1417 xen_raw_printk("physdev_op failed %d\n", rc);
1418
1419 #ifdef CONFIG_X86_32
1420 /* set up basic CPUID stuff */
1421 cpu_detect(&new_cpu_data);
1422 new_cpu_data.hard_math = 1;
1423 new_cpu_data.wp_works_ok = 1;
1424 new_cpu_data.x86_capability[0] = cpuid_edx(1);
1425 #endif
1426
1427 /* Poke various useful things into boot_params */
1428 boot_params.hdr.type_of_loader = (9 << 4) | 0;
1429 boot_params.hdr.ramdisk_image = xen_start_info->mod_start
1430 ? __pa(xen_start_info->mod_start) : 0;
1431 boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
1432 boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
1433
1434 if (!xen_initial_domain()) {
1435 add_preferred_console("xenboot", 0, NULL);
1436 add_preferred_console("tty", 0, NULL);
1437 add_preferred_console("hvc", 0, NULL);
1438 if (pci_xen)
1439 x86_init.pci.arch_init = pci_xen_init;
1440 } else {
1441 const struct dom0_vga_console_info *info =
1442 (void *)((char *)xen_start_info +
1443 xen_start_info->console.dom0.info_off);
1444
1445 xen_init_vga(info, xen_start_info->console.dom0.info_size);
1446 xen_start_info->console.domU.mfn = 0;
1447 xen_start_info->console.domU.evtchn = 0;
1448
1449 /* Make sure ACS will be enabled */
1450 pci_request_acs();
1451 }
1452 #ifdef CONFIG_PCI
1453 /* PCI BIOS service won't work from a PV guest. */
1454 pci_probe &= ~PCI_PROBE_BIOS;
1455 #endif
1456 xen_raw_console_write("about to get started...\n");
1457
1458 xen_setup_runstate_info(0);
1459
1460 /* Start the world */
1461 #ifdef CONFIG_X86_32
1462 i386_start_kernel();
1463 #else
1464 x86_64_start_reservations((char *)__pa_symbol(&boot_params));
1465 #endif
1466 }
1467
init_hvm_pv_info(int * major,int * minor)1468 static int init_hvm_pv_info(int *major, int *minor)
1469 {
1470 uint32_t eax, ebx, ecx, edx, pages, msr, base;
1471 u64 pfn;
1472
1473 base = xen_cpuid_base();
1474 cpuid(base + 1, &eax, &ebx, &ecx, &edx);
1475
1476 *major = eax >> 16;
1477 *minor = eax & 0xffff;
1478 printk(KERN_INFO "Xen version %d.%d.\n", *major, *minor);
1479
1480 cpuid(base + 2, &pages, &msr, &ecx, &edx);
1481
1482 pfn = __pa(hypercall_page);
1483 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
1484
1485 xen_setup_features();
1486
1487 pv_info.name = "Xen HVM";
1488
1489 xen_domain_type = XEN_HVM_DOMAIN;
1490
1491 return 0;
1492 }
1493
xen_hvm_init_shared_info(void)1494 void __ref xen_hvm_init_shared_info(void)
1495 {
1496 int cpu;
1497 struct xen_add_to_physmap xatp;
1498 static struct shared_info *shared_info_page = 0;
1499
1500 if (!shared_info_page)
1501 shared_info_page = (struct shared_info *)
1502 extend_brk(PAGE_SIZE, PAGE_SIZE);
1503 xatp.domid = DOMID_SELF;
1504 xatp.idx = 0;
1505 xatp.space = XENMAPSPACE_shared_info;
1506 xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
1507 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
1508 BUG();
1509
1510 HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
1511
1512 /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
1513 * page, we use it in the event channel upcall and in some pvclock
1514 * related functions. We don't need the vcpu_info placement
1515 * optimizations because we don't use any pv_mmu or pv_irq op on
1516 * HVM.
1517 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
1518 * online but xen_hvm_init_shared_info is run at resume time too and
1519 * in that case multiple vcpus might be online. */
1520 for_each_online_cpu(cpu) {
1521 per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
1522 }
1523 }
1524
1525 #ifdef CONFIG_XEN_PVHVM
xen_hvm_cpu_notify(struct notifier_block * self,unsigned long action,void * hcpu)1526 static int __cpuinit xen_hvm_cpu_notify(struct notifier_block *self,
1527 unsigned long action, void *hcpu)
1528 {
1529 int cpu = (long)hcpu;
1530 switch (action) {
1531 case CPU_UP_PREPARE:
1532 xen_vcpu_setup(cpu);
1533 if (xen_have_vector_callback) {
1534 xen_init_lock_cpu(cpu);
1535 if (xen_feature(XENFEAT_hvm_safe_pvclock))
1536 xen_setup_timer(cpu);
1537 }
1538 break;
1539 default:
1540 break;
1541 }
1542 return NOTIFY_OK;
1543 }
1544
1545 static struct notifier_block xen_hvm_cpu_notifier __cpuinitdata = {
1546 .notifier_call = xen_hvm_cpu_notify,
1547 };
1548
xen_hvm_guest_init(void)1549 static void __init xen_hvm_guest_init(void)
1550 {
1551 int r;
1552 int major, minor;
1553
1554 r = init_hvm_pv_info(&major, &minor);
1555 if (r < 0)
1556 return;
1557
1558 xen_hvm_init_shared_info();
1559
1560 if (xen_feature(XENFEAT_hvm_callback_vector))
1561 xen_have_vector_callback = 1;
1562 xen_hvm_smp_init();
1563 register_cpu_notifier(&xen_hvm_cpu_notifier);
1564 xen_unplug_emulated_devices();
1565 x86_init.irqs.intr_init = xen_init_IRQ;
1566 xen_hvm_init_time_ops();
1567 xen_hvm_init_mmu_ops();
1568 }
1569
xen_hvm_platform(void)1570 static bool __init xen_hvm_platform(void)
1571 {
1572 if (xen_pv_domain())
1573 return false;
1574
1575 if (!xen_cpuid_base())
1576 return false;
1577
1578 return true;
1579 }
1580
xen_hvm_need_lapic(void)1581 bool xen_hvm_need_lapic(void)
1582 {
1583 if (xen_pv_domain())
1584 return false;
1585 if (!xen_hvm_domain())
1586 return false;
1587 if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
1588 return false;
1589 return true;
1590 }
1591 EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
1592
1593 const struct hypervisor_x86 x86_hyper_xen_hvm __refconst = {
1594 .name = "Xen HVM",
1595 .detect = xen_hvm_platform,
1596 .init_platform = xen_hvm_guest_init,
1597 };
1598 EXPORT_SYMBOL(x86_hyper_xen_hvm);
1599 #endif
1600