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#include <linux/edd.h>
35
36#include <xen/xen.h>
37#include <xen/events.h>
38#include <xen/interface/xen.h>
39#include <xen/interface/version.h>
40#include <xen/interface/physdev.h>
41#include <xen/interface/vcpu.h>
42#include <xen/interface/memory.h>
43#include <xen/interface/xen-mca.h>
44#include <xen/features.h>
45#include <xen/page.h>
46#include <xen/hvm.h>
47#include <xen/hvc-console.h>
48#include <xen/acpi.h>
49
50#include <asm/paravirt.h>
51#include <asm/apic.h>
52#include <asm/page.h>
53#include <asm/xen/pci.h>
54#include <asm/xen/hypercall.h>
55#include <asm/xen/hypervisor.h>
56#include <asm/fixmap.h>
57#include <asm/processor.h>
58#include <asm/proto.h>
59#include <asm/msr-index.h>
60#include <asm/traps.h>
61#include <asm/setup.h>
62#include <asm/desc.h>
63#include <asm/pgalloc.h>
64#include <asm/pgtable.h>
65#include <asm/tlbflush.h>
66#include <asm/reboot.h>
67#include <asm/stackprotector.h>
68#include <asm/hypervisor.h>
69#include <asm/mwait.h>
70#include <asm/pci_x86.h>
71#include <asm/pat.h>
72
73#ifdef CONFIG_ACPI
74#include <linux/acpi.h>
75#include <asm/acpi.h>
76#include <acpi/pdc_intel.h>
77#include <acpi/processor.h>
78#include <xen/interface/platform.h>
79#endif
80
81#include "xen-ops.h"
82#include "mmu.h"
83#include "smp.h"
84#include "multicalls.h"
85
86EXPORT_SYMBOL_GPL(hypercall_page);
87
88/*
89 * Pointer to the xen_vcpu_info structure or
90 * &HYPERVISOR_shared_info->vcpu_info[cpu]. See xen_hvm_init_shared_info
91 * and xen_vcpu_setup for details. By default it points to share_info->vcpu_info
92 * but if the hypervisor supports VCPUOP_register_vcpu_info then it can point
93 * to xen_vcpu_info. The pointer is used in __xen_evtchn_do_upcall to
94 * acknowledge pending events.
95 * Also more subtly it is used by the patched version of irq enable/disable
96 * e.g. xen_irq_enable_direct and xen_iret in PV mode.
97 *
98 * The desire to be able to do those mask/unmask operations as a single
99 * instruction by using the per-cpu offset held in %gs is the real reason
100 * vcpu info is in a per-cpu pointer and the original reason for this
101 * hypercall.
102 *
103 */
104DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
105
106/*
107 * Per CPU pages used if hypervisor supports VCPUOP_register_vcpu_info
108 * hypercall. This can be used both in PV and PVHVM mode. The structure
109 * overrides the default per_cpu(xen_vcpu, cpu) value.
110 */
111DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
112
113enum xen_domain_type xen_domain_type = XEN_NATIVE;
114EXPORT_SYMBOL_GPL(xen_domain_type);
115
116unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START;
117EXPORT_SYMBOL(machine_to_phys_mapping);
118unsigned long machine_to_phys_nr;
119EXPORT_SYMBOL(machine_to_phys_nr);
120
121struct start_info *xen_start_info;
122EXPORT_SYMBOL_GPL(xen_start_info);
123
124struct shared_info xen_dummy_shared_info;
125
126void *xen_initial_gdt;
127
128RESERVE_BRK(shared_info_page_brk, PAGE_SIZE);
129__read_mostly int xen_have_vector_callback;
130EXPORT_SYMBOL_GPL(xen_have_vector_callback);
131
132/*
133 * Point at some empty memory to start with. We map the real shared_info
134 * page as soon as fixmap is up and running.
135 */
136struct shared_info *HYPERVISOR_shared_info = &xen_dummy_shared_info;
137
138/*
139 * Flag to determine whether vcpu info placement is available on all
140 * VCPUs. We assume it is to start with, and then set it to zero on
141 * the first failure. This is because it can succeed on some VCPUs
142 * and not others, since it can involve hypervisor memory allocation,
143 * or because the guest failed to guarantee all the appropriate
144 * constraints on all VCPUs (ie buffer can't cross a page boundary).
145 *
146 * Note that any particular CPU may be using a placed vcpu structure,
147 * but we can only optimise if the all are.
148 *
149 * 0: not available, 1: available
150 */
151static int have_vcpu_info_placement = 1;
152
153struct tls_descs {
154 struct desc_struct desc[3];
155};
156
157/*
158 * Updating the 3 TLS descriptors in the GDT on every task switch is
159 * surprisingly expensive so we avoid updating them if they haven't
160 * changed. Since Xen writes different descriptors than the one
161 * passed in the update_descriptor hypercall we keep shadow copies to
162 * compare against.
163 */
164static DEFINE_PER_CPU(struct tls_descs, shadow_tls_desc);
165
166static void clamp_max_cpus(void)
167{
168#ifdef CONFIG_SMP
169 if (setup_max_cpus > MAX_VIRT_CPUS)
170 setup_max_cpus = MAX_VIRT_CPUS;
171#endif
172}
173
174static void xen_vcpu_setup(int cpu)
175{
176 struct vcpu_register_vcpu_info info;
177 int err;
178 struct vcpu_info *vcpup;
179
180 BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
181
182 /*
183 * This path is called twice on PVHVM - first during bootup via
184 * smp_init -> xen_hvm_cpu_notify, and then if the VCPU is being
185 * hotplugged: cpu_up -> xen_hvm_cpu_notify.
186 * As we can only do the VCPUOP_register_vcpu_info once lets
187 * not over-write its result.
188 *
189 * For PV it is called during restore (xen_vcpu_restore) and bootup
190 * (xen_setup_vcpu_info_placement). The hotplug mechanism does not
191 * use this function.
192 */
193 if (xen_hvm_domain()) {
194 if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu))
195 return;
196 }
197 if (cpu < MAX_VIRT_CPUS)
198 per_cpu(xen_vcpu,cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
199
200 if (!have_vcpu_info_placement) {
201 if (cpu >= MAX_VIRT_CPUS)
202 clamp_max_cpus();
203 return;
204 }
205
206 vcpup = &per_cpu(xen_vcpu_info, cpu);
207 info.mfn = arbitrary_virt_to_mfn(vcpup);
208 info.offset = offset_in_page(vcpup);
209
210 /* Check to see if the hypervisor will put the vcpu_info
211 structure where we want it, which allows direct access via
212 a percpu-variable.
213 N.B. This hypercall can _only_ be called once per CPU. Subsequent
214 calls will error out with -EINVAL. This is due to the fact that
215 hypervisor has no unregister variant and this hypercall does not
216 allow to over-write info.mfn and info.offset.
217 */
218 err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
219
220 if (err) {
221 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
222 have_vcpu_info_placement = 0;
223 clamp_max_cpus();
224 } else {
225 /* This cpu is using the registered vcpu info, even if
226 later ones fail to. */
227 per_cpu(xen_vcpu, cpu) = vcpup;
228 }
229}
230
231/*
232 * On restore, set the vcpu placement up again.
233 * If it fails, then we're in a bad state, since
234 * we can't back out from using it...
235 */
236void xen_vcpu_restore(void)
237{
238 int cpu;
239
240 for_each_possible_cpu(cpu) {
241 bool other_cpu = (cpu != smp_processor_id());
242 bool is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL);
243
244 if (other_cpu && is_up &&
245 HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL))
246 BUG();
247
248 xen_setup_runstate_info(cpu);
249
250 if (have_vcpu_info_placement)
251 xen_vcpu_setup(cpu);
252
253 if (other_cpu && is_up &&
254 HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
255 BUG();
256 }
257}
258
259static void __init xen_banner(void)
260{
261 unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
262 struct xen_extraversion extra;
263 HYPERVISOR_xen_version(XENVER_extraversion, &extra);
264
265 pr_info("Booting paravirtualized kernel %son %s\n",
266 xen_feature(XENFEAT_auto_translated_physmap) ?
267 "with PVH extensions " : "", pv_info.name);
268 printk(KERN_INFO "Xen version: %d.%d%s%s\n",
269 version >> 16, version & 0xffff, extra.extraversion,
270 xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
271}
272/* Check if running on Xen version (major, minor) or later */
273bool
274xen_running_on_version_or_later(unsigned int major, unsigned int minor)
275{
276 unsigned int version;
277
278 if (!xen_domain())
279 return false;
280
281 version = HYPERVISOR_xen_version(XENVER_version, NULL);
282 if ((((version >> 16) == major) && ((version & 0xffff) >= minor)) ||
283 ((version >> 16) > major))
284 return true;
285 return false;
286}
287
288#define CPUID_THERM_POWER_LEAF 6
289#define APERFMPERF_PRESENT 0
290
291static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
292static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
293
294static __read_mostly unsigned int cpuid_leaf1_ecx_set_mask;
295static __read_mostly unsigned int cpuid_leaf5_ecx_val;
296static __read_mostly unsigned int cpuid_leaf5_edx_val;
297
298static void xen_cpuid(unsigned int *ax, unsigned int *bx,
299 unsigned int *cx, unsigned int *dx)
300{
301 unsigned maskebx = ~0;
302 unsigned maskecx = ~0;
303 unsigned maskedx = ~0;
304 unsigned setecx = 0;
305 /*
306 * Mask out inconvenient features, to try and disable as many
307 * unsupported kernel subsystems as possible.
308 */
309 switch (*ax) {
310 case 1:
311 maskecx = cpuid_leaf1_ecx_mask;
312 setecx = cpuid_leaf1_ecx_set_mask;
313 maskedx = cpuid_leaf1_edx_mask;
314 break;
315
316 case CPUID_MWAIT_LEAF:
317 /* Synthesize the values.. */
318 *ax = 0;
319 *bx = 0;
320 *cx = cpuid_leaf5_ecx_val;
321 *dx = cpuid_leaf5_edx_val;
322 return;
323
324 case CPUID_THERM_POWER_LEAF:
325 /* Disabling APERFMPERF for kernel usage */
326 maskecx = ~(1 << APERFMPERF_PRESENT);
327 break;
328
329 case 0xb:
330 /* Suppress extended topology stuff */
331 maskebx = 0;
332 break;
333 }
334
335 asm(XEN_EMULATE_PREFIX "cpuid"
336 : "=a" (*ax),
337 "=b" (*bx),
338 "=c" (*cx),
339 "=d" (*dx)
340 : "0" (*ax), "2" (*cx));
341
342 *bx &= maskebx;
343 *cx &= maskecx;
344 *cx |= setecx;
345 *dx &= maskedx;
346
347}
348
349static bool __init xen_check_mwait(void)
350{
351#ifdef CONFIG_ACPI
352 struct xen_platform_op op = {
353 .cmd = XENPF_set_processor_pminfo,
354 .u.set_pminfo.id = -1,
355 .u.set_pminfo.type = XEN_PM_PDC,
356 };
357 uint32_t buf[3];
358 unsigned int ax, bx, cx, dx;
359 unsigned int mwait_mask;
360
361 /* We need to determine whether it is OK to expose the MWAIT
362 * capability to the kernel to harvest deeper than C3 states from ACPI
363 * _CST using the processor_harvest_xen.c module. For this to work, we
364 * need to gather the MWAIT_LEAF values (which the cstate.c code
365 * checks against). The hypervisor won't expose the MWAIT flag because
366 * it would break backwards compatibility; so we will find out directly
367 * from the hardware and hypercall.
368 */
369 if (!xen_initial_domain())
370 return false;
371
372 /*
373 * When running under platform earlier than Xen4.2, do not expose
374 * mwait, to avoid the risk of loading native acpi pad driver
375 */
376 if (!xen_running_on_version_or_later(4, 2))
377 return false;
378
379 ax = 1;
380 cx = 0;
381
382 native_cpuid(&ax, &bx, &cx, &dx);
383
384 mwait_mask = (1 << (X86_FEATURE_EST % 32)) |
385 (1 << (X86_FEATURE_MWAIT % 32));
386
387 if ((cx & mwait_mask) != mwait_mask)
388 return false;
389
390 /* We need to emulate the MWAIT_LEAF and for that we need both
391 * ecx and edx. The hypercall provides only partial information.
392 */
393
394 ax = CPUID_MWAIT_LEAF;
395 bx = 0;
396 cx = 0;
397 dx = 0;
398
399 native_cpuid(&ax, &bx, &cx, &dx);
400
401 /* Ask the Hypervisor whether to clear ACPI_PDC_C_C2C3_FFH. If so,
402 * don't expose MWAIT_LEAF and let ACPI pick the IOPORT version of C3.
403 */
404 buf[0] = ACPI_PDC_REVISION_ID;
405 buf[1] = 1;
406 buf[2] = (ACPI_PDC_C_CAPABILITY_SMP | ACPI_PDC_EST_CAPABILITY_SWSMP);
407
408 set_xen_guest_handle(op.u.set_pminfo.pdc, buf);
409
410 if ((HYPERVISOR_dom0_op(&op) == 0) &&
411 (buf[2] & (ACPI_PDC_C_C1_FFH | ACPI_PDC_C_C2C3_FFH))) {
412 cpuid_leaf5_ecx_val = cx;
413 cpuid_leaf5_edx_val = dx;
414 }
415 return true;
416#else
417 return false;
418#endif
419}
420static void __init xen_init_cpuid_mask(void)
421{
422 unsigned int ax, bx, cx, dx;
423 unsigned int xsave_mask;
424
425 cpuid_leaf1_edx_mask =
426 ~((1 << X86_FEATURE_MTRR) | /* disable MTRR */
427 (1 << X86_FEATURE_ACC)); /* thermal monitoring */
428
429 if (!xen_initial_domain())
430 cpuid_leaf1_edx_mask &=
431 ~((1 << X86_FEATURE_ACPI)); /* disable ACPI */
432
433 cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_X2APIC % 32));
434
435 ax = 1;
436 cx = 0;
437 cpuid(1, &ax, &bx, &cx, &dx);
438
439 xsave_mask =
440 (1 << (X86_FEATURE_XSAVE % 32)) |
441 (1 << (X86_FEATURE_OSXSAVE % 32));
442
443 /* Xen will set CR4.OSXSAVE if supported and not disabled by force */
444 if ((cx & xsave_mask) != xsave_mask)
445 cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */
446 if (xen_check_mwait())
447 cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32));
448}
449
450static void xen_set_debugreg(int reg, unsigned long val)
451{
452 HYPERVISOR_set_debugreg(reg, val);
453}
454
455static unsigned long xen_get_debugreg(int reg)
456{
457 return HYPERVISOR_get_debugreg(reg);
458}
459
460static void xen_end_context_switch(struct task_struct *next)
461{
462 xen_mc_flush();
463 paravirt_end_context_switch(next);
464}
465
466static unsigned long xen_store_tr(void)
467{
468 return 0;
469}
470
471/*
472 * Set the page permissions for a particular virtual address. If the
473 * address is a vmalloc mapping (or other non-linear mapping), then
474 * find the linear mapping of the page and also set its protections to
475 * match.
476 */
477static void set_aliased_prot(void *v, pgprot_t prot)
478{
479 int level;
480 pte_t *ptep;
481 pte_t pte;
482 unsigned long pfn;
483 struct page *page;
484
485 ptep = lookup_address((unsigned long)v, &level);
486 BUG_ON(ptep == NULL);
487
488 pfn = pte_pfn(*ptep);
489 page = pfn_to_page(pfn);
490
491 pte = pfn_pte(pfn, prot);
492
493 if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
494 BUG();
495
496 if (!PageHighMem(page)) {
497 void *av = __va(PFN_PHYS(pfn));
498
499 if (av != v)
500 if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
501 BUG();
502 } else
503 kmap_flush_unused();
504}
505
506static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
507{
508 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
509 int i;
510
511 for(i = 0; i < entries; i += entries_per_page)
512 set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
513}
514
515static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
516{
517 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
518 int i;
519
520 for(i = 0; i < entries; i += entries_per_page)
521 set_aliased_prot(ldt + i, PAGE_KERNEL);
522}
523
524static void xen_set_ldt(const void *addr, unsigned entries)
525{
526 struct mmuext_op *op;
527 struct multicall_space mcs = xen_mc_entry(sizeof(*op));
528
529 trace_xen_cpu_set_ldt(addr, entries);
530
531 op = mcs.args;
532 op->cmd = MMUEXT_SET_LDT;
533 op->arg1.linear_addr = (unsigned long)addr;
534 op->arg2.nr_ents = entries;
535
536 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
537
538 xen_mc_issue(PARAVIRT_LAZY_CPU);
539}
540
541static void xen_load_gdt(const struct desc_ptr *dtr)
542{
543 unsigned long va = dtr->address;
544 unsigned int size = dtr->size + 1;
545 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
546 unsigned long frames[pages];
547 int f;
548
549 /*
550 * A GDT can be up to 64k in size, which corresponds to 8192
551 * 8-byte entries, or 16 4k pages..
552 */
553
554 BUG_ON(size > 65536);
555 BUG_ON(va & ~PAGE_MASK);
556
557 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
558 int level;
559 pte_t *ptep;
560 unsigned long pfn, mfn;
561 void *virt;
562
563 /*
564 * The GDT is per-cpu and is in the percpu data area.
565 * That can be virtually mapped, so we need to do a
566 * page-walk to get the underlying MFN for the
567 * hypercall. The page can also be in the kernel's
568 * linear range, so we need to RO that mapping too.
569 */
570 ptep = lookup_address(va, &level);
571 BUG_ON(ptep == NULL);
572
573 pfn = pte_pfn(*ptep);
574 mfn = pfn_to_mfn(pfn);
575 virt = __va(PFN_PHYS(pfn));
576
577 frames[f] = mfn;
578
579 make_lowmem_page_readonly((void *)va);
580 make_lowmem_page_readonly(virt);
581 }
582
583 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
584 BUG();
585}
586
587/*
588 * load_gdt for early boot, when the gdt is only mapped once
589 */
590static void __init xen_load_gdt_boot(const struct desc_ptr *dtr)
591{
592 unsigned long va = dtr->address;
593 unsigned int size = dtr->size + 1;
594 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
595 unsigned long frames[pages];
596 int f;
597
598 /*
599 * A GDT can be up to 64k in size, which corresponds to 8192
600 * 8-byte entries, or 16 4k pages..
601 */
602
603 BUG_ON(size > 65536);
604 BUG_ON(va & ~PAGE_MASK);
605
606 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
607 pte_t pte;
608 unsigned long pfn, mfn;
609
610 pfn = virt_to_pfn(va);
611 mfn = pfn_to_mfn(pfn);
612
613 pte = pfn_pte(pfn, PAGE_KERNEL_RO);
614
615 if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0))
616 BUG();
617
618 frames[f] = mfn;
619 }
620
621 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
622 BUG();
623}
624
625static inline bool desc_equal(const struct desc_struct *d1,
626 const struct desc_struct *d2)
627{
628 return d1->a == d2->a && d1->b == d2->b;
629}
630
631static void load_TLS_descriptor(struct thread_struct *t,
632 unsigned int cpu, unsigned int i)
633{
634 struct desc_struct *shadow = &per_cpu(shadow_tls_desc, cpu).desc[i];
635 struct desc_struct *gdt;
636 xmaddr_t maddr;
637 struct multicall_space mc;
638
639 if (desc_equal(shadow, &t->tls_array[i]))
640 return;
641
642 *shadow = t->tls_array[i];
643
644 gdt = get_cpu_gdt_table(cpu);
645 maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
646 mc = __xen_mc_entry(0);
647
648 MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
649}
650
651static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
652{
653 /*
654 * XXX sleazy hack: If we're being called in a lazy-cpu zone
655 * and lazy gs handling is enabled, it means we're in a
656 * context switch, and %gs has just been saved. This means we
657 * can zero it out to prevent faults on exit from the
658 * hypervisor if the next process has no %gs. Either way, it
659 * has been saved, and the new value will get loaded properly.
660 * This will go away as soon as Xen has been modified to not
661 * save/restore %gs for normal hypercalls.
662 *
663 * On x86_64, this hack is not used for %gs, because gs points
664 * to KERNEL_GS_BASE (and uses it for PDA references), so we
665 * must not zero %gs on x86_64
666 *
667 * For x86_64, we need to zero %fs, otherwise we may get an
668 * exception between the new %fs descriptor being loaded and
669 * %fs being effectively cleared at __switch_to().
670 */
671 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
672#ifdef CONFIG_X86_32
673 lazy_load_gs(0);
674#else
675 loadsegment(fs, 0);
676#endif
677 }
678
679 xen_mc_batch();
680
681 load_TLS_descriptor(t, cpu, 0);
682 load_TLS_descriptor(t, cpu, 1);
683 load_TLS_descriptor(t, cpu, 2);
684
685 xen_mc_issue(PARAVIRT_LAZY_CPU);
686}
687
688#ifdef CONFIG_X86_64
689static void xen_load_gs_index(unsigned int idx)
690{
691 if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
692 BUG();
693}
694#endif
695
696static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
697 const void *ptr)
698{
699 xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
700 u64 entry = *(u64 *)ptr;
701
702 trace_xen_cpu_write_ldt_entry(dt, entrynum, entry);
703
704 preempt_disable();
705
706 xen_mc_flush();
707 if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
708 BUG();
709
710 preempt_enable();
711}
712
713static int cvt_gate_to_trap(int vector, const gate_desc *val,
714 struct trap_info *info)
715{
716 unsigned long addr;
717
718 if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT)
719 return 0;
720
721 info->vector = vector;
722
723 addr = gate_offset(*val);
724#ifdef CONFIG_X86_64
725 /*
726 * Look for known traps using IST, and substitute them
727 * appropriately. The debugger ones are the only ones we care
728 * about. Xen will handle faults like double_fault,
729 * so we should never see them. Warn if
730 * there's an unexpected IST-using fault handler.
731 */
732 if (addr == (unsigned long)debug)
733 addr = (unsigned long)xen_debug;
734 else if (addr == (unsigned long)int3)
735 addr = (unsigned long)xen_int3;
736 else if (addr == (unsigned long)stack_segment)
737 addr = (unsigned long)xen_stack_segment;
738 else if (addr == (unsigned long)double_fault) {
739 /* Don't need to handle these */
740 return 0;
741#ifdef CONFIG_X86_MCE
742 } else if (addr == (unsigned long)machine_check) {
743 /*
744 * when xen hypervisor inject vMCE to guest,
745 * use native mce handler to handle it
746 */
747 ;
748#endif
749 } else if (addr == (unsigned long)nmi)
750 /*
751 * Use the native version as well.
752 */
753 ;
754 else {
755 /* Some other trap using IST? */
756 if (WARN_ON(val->ist != 0))
757 return 0;
758 }
759#endif /* CONFIG_X86_64 */
760 info->address = addr;
761
762 info->cs = gate_segment(*val);
763 info->flags = val->dpl;
764 /* interrupt gates clear IF */
765 if (val->type == GATE_INTERRUPT)
766 info->flags |= 1 << 2;
767
768 return 1;
769}
770
771/* Locations of each CPU's IDT */
772static DEFINE_PER_CPU(struct desc_ptr, idt_desc);
773
774/* Set an IDT entry. If the entry is part of the current IDT, then
775 also update Xen. */
776static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
777{
778 unsigned long p = (unsigned long)&dt[entrynum];
779 unsigned long start, end;
780
781 trace_xen_cpu_write_idt_entry(dt, entrynum, g);
782
783 preempt_disable();
784
785 start = __this_cpu_read(idt_desc.address);
786 end = start + __this_cpu_read(idt_desc.size) + 1;
787
788 xen_mc_flush();
789
790 native_write_idt_entry(dt, entrynum, g);
791
792 if (p >= start && (p + 8) <= end) {
793 struct trap_info info[2];
794
795 info[1].address = 0;
796
797 if (cvt_gate_to_trap(entrynum, g, &info[0]))
798 if (HYPERVISOR_set_trap_table(info))
799 BUG();
800 }
801
802 preempt_enable();
803}
804
805static void xen_convert_trap_info(const struct desc_ptr *desc,
806 struct trap_info *traps)
807{
808 unsigned in, out, count;
809
810 count = (desc->size+1) / sizeof(gate_desc);
811 BUG_ON(count > 256);
812
813 for (in = out = 0; in < count; in++) {
814 gate_desc *entry = (gate_desc*)(desc->address) + in;
815
816 if (cvt_gate_to_trap(in, entry, &traps[out]))
817 out++;
818 }
819 traps[out].address = 0;
820}
821
822void xen_copy_trap_info(struct trap_info *traps)
823{
824 const struct desc_ptr *desc = &__get_cpu_var(idt_desc);
825
826 xen_convert_trap_info(desc, traps);
827}
828
829/* Load a new IDT into Xen. In principle this can be per-CPU, so we
830 hold a spinlock to protect the static traps[] array (static because
831 it avoids allocation, and saves stack space). */
832static void xen_load_idt(const struct desc_ptr *desc)
833{
834 static DEFINE_SPINLOCK(lock);
835 static struct trap_info traps[257];
836
837 trace_xen_cpu_load_idt(desc);
838
839 spin_lock(&lock);
840
841 __get_cpu_var(idt_desc) = *desc;
842
843 xen_convert_trap_info(desc, traps);
844
845 xen_mc_flush();
846 if (HYPERVISOR_set_trap_table(traps))
847 BUG();
848
849 spin_unlock(&lock);
850}
851
852/* Write a GDT descriptor entry. Ignore LDT descriptors, since
853 they're handled differently. */
854static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
855 const void *desc, int type)
856{
857 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
858
859 preempt_disable();
860
861 switch (type) {
862 case DESC_LDT:
863 case DESC_TSS:
864 /* ignore */
865 break;
866
867 default: {
868 xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]);
869
870 xen_mc_flush();
871 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
872 BUG();
873 }
874
875 }
876
877 preempt_enable();
878}
879
880/*
881 * Version of write_gdt_entry for use at early boot-time needed to
882 * update an entry as simply as possible.
883 */
884static void __init xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
885 const void *desc, int type)
886{
887 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
888
889 switch (type) {
890 case DESC_LDT:
891 case DESC_TSS:
892 /* ignore */
893 break;
894
895 default: {
896 xmaddr_t maddr = virt_to_machine(&dt[entry]);
897
898 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
899 dt[entry] = *(struct desc_struct *)desc;
900 }
901
902 }
903}
904
905static void xen_load_sp0(struct tss_struct *tss,
906 struct thread_struct *thread)
907{
908 struct multicall_space mcs;
909
910 mcs = xen_mc_entry(0);
911 MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
912 xen_mc_issue(PARAVIRT_LAZY_CPU);
913}
914
915static void xen_set_iopl_mask(unsigned mask)
916{
917 struct physdev_set_iopl set_iopl;
918
919 /* Force the change at ring 0. */
920 set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
921 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
922}
923
924static void xen_io_delay(void)
925{
926}
927
928#ifdef CONFIG_X86_LOCAL_APIC
929static unsigned long xen_set_apic_id(unsigned int x)
930{
931 WARN_ON(1);
932 return x;
933}
934static unsigned int xen_get_apic_id(unsigned long x)
935{
936 return ((x)>>24) & 0xFFu;
937}
938static u32 xen_apic_read(u32 reg)
939{
940 struct xen_platform_op op = {
941 .cmd = XENPF_get_cpuinfo,
942 .interface_version = XENPF_INTERFACE_VERSION,
943 .u.pcpu_info.xen_cpuid = 0,
944 };
945 int ret = 0;
946
947 /* Shouldn't need this as APIC is turned off for PV, and we only
948 * get called on the bootup processor. But just in case. */
949 if (!xen_initial_domain() || smp_processor_id())
950 return 0;
951
952 if (reg == APIC_LVR)
953 return 0x10;
954
955 if (reg != APIC_ID)
956 return 0;
957
958 ret = HYPERVISOR_dom0_op(&op);
959 if (ret)
960 return 0;
961
962 return op.u.pcpu_info.apic_id << 24;
963}
964
965static void xen_apic_write(u32 reg, u32 val)
966{
967 /* Warn to see if there's any stray references */
968 WARN_ON(1);
969}
970
971static u64 xen_apic_icr_read(void)
972{
973 return 0;
974}
975
976static void xen_apic_icr_write(u32 low, u32 id)
977{
978 /* Warn to see if there's any stray references */
979 WARN_ON(1);
980}
981
982static void xen_apic_wait_icr_idle(void)
983{
984 return;
985}
986
987static u32 xen_safe_apic_wait_icr_idle(void)
988{
989 return 0;
990}
991
992static void set_xen_basic_apic_ops(void)
993{
994 apic->read = xen_apic_read;
995 apic->write = xen_apic_write;
996 apic->icr_read = xen_apic_icr_read;
997 apic->icr_write = xen_apic_icr_write;
998 apic->wait_icr_idle = xen_apic_wait_icr_idle;
999 apic->safe_wait_icr_idle = xen_safe_apic_wait_icr_idle;
1000 apic->set_apic_id = xen_set_apic_id;
1001 apic->get_apic_id = xen_get_apic_id;
1002
1003#ifdef CONFIG_SMP
1004 apic->send_IPI_allbutself = xen_send_IPI_allbutself;
1005 apic->send_IPI_mask_allbutself = xen_send_IPI_mask_allbutself;
1006 apic->send_IPI_mask = xen_send_IPI_mask;
1007 apic->send_IPI_all = xen_send_IPI_all;
1008 apic->send_IPI_self = xen_send_IPI_self;
1009#endif
1010}
1011
1012#endif
1013
1014static void xen_clts(void)
1015{
1016 struct multicall_space mcs;
1017
1018 mcs = xen_mc_entry(0);
1019
1020 MULTI_fpu_taskswitch(mcs.mc, 0);
1021
1022 xen_mc_issue(PARAVIRT_LAZY_CPU);
1023}
1024
1025static DEFINE_PER_CPU(unsigned long, xen_cr0_value);
1026
1027static unsigned long xen_read_cr0(void)
1028{
1029 unsigned long cr0 = this_cpu_read(xen_cr0_value);
1030
1031 if (unlikely(cr0 == 0)) {
1032 cr0 = native_read_cr0();
1033 this_cpu_write(xen_cr0_value, cr0);
1034 }
1035
1036 return cr0;
1037}
1038
1039static void xen_write_cr0(unsigned long cr0)
1040{
1041 struct multicall_space mcs;
1042
1043 this_cpu_write(xen_cr0_value, cr0);
1044
1045 /* Only pay attention to cr0.TS; everything else is
1046 ignored. */
1047 mcs = xen_mc_entry(0);
1048
1049 MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
1050
1051 xen_mc_issue(PARAVIRT_LAZY_CPU);
1052}
1053
1054static void xen_write_cr4(unsigned long cr4)
1055{
1056 cr4 &= ~X86_CR4_PGE;
1057 cr4 &= ~X86_CR4_PSE;
1058
1059 native_write_cr4(cr4);
1060}
1061#ifdef CONFIG_X86_64
1062static inline unsigned long xen_read_cr8(void)
1063{
1064 return 0;
1065}
1066static inline void xen_write_cr8(unsigned long val)
1067{
1068 BUG_ON(val);
1069}
1070#endif
1071static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
1072{
1073 int ret;
1074
1075 ret = 0;
1076
1077 switch (msr) {
1078#ifdef CONFIG_X86_64
1079 unsigned which;
1080 u64 base;
1081
1082 case MSR_FS_BASE: which = SEGBASE_FS; goto set;
1083 case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set;
1084 case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set;
1085
1086 set:
1087 base = ((u64)high << 32) | low;
1088 if (HYPERVISOR_set_segment_base(which, base) != 0)
1089 ret = -EIO;
1090 break;
1091#endif
1092
1093 case MSR_STAR:
1094 case MSR_CSTAR:
1095 case MSR_LSTAR:
1096 case MSR_SYSCALL_MASK:
1097 case MSR_IA32_SYSENTER_CS:
1098 case MSR_IA32_SYSENTER_ESP:
1099 case MSR_IA32_SYSENTER_EIP:
1100 /* Fast syscall setup is all done in hypercalls, so
1101 these are all ignored. Stub them out here to stop
1102 Xen console noise. */
1103 break;
1104
1105 case MSR_IA32_CR_PAT:
1106 if (smp_processor_id() == 0)
1107 xen_set_pat(((u64)high << 32) | low);
1108 break;
1109
1110 default:
1111 ret = native_write_msr_safe(msr, low, high);
1112 }
1113
1114 return ret;
1115}
1116
1117void xen_setup_shared_info(void)
1118{
1119 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1120 set_fixmap(FIX_PARAVIRT_BOOTMAP,
1121 xen_start_info->shared_info);
1122
1123 HYPERVISOR_shared_info =
1124 (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
1125 } else
1126 HYPERVISOR_shared_info =
1127 (struct shared_info *)__va(xen_start_info->shared_info);
1128
1129#ifndef CONFIG_SMP
1130 /* In UP this is as good a place as any to set up shared info */
1131 xen_setup_vcpu_info_placement();
1132#endif
1133
1134 xen_setup_mfn_list_list();
1135}
1136
1137/* This is called once we have the cpu_possible_mask */
1138void xen_setup_vcpu_info_placement(void)
1139{
1140 int cpu;
1141
1142 for_each_possible_cpu(cpu)
1143 xen_vcpu_setup(cpu);
1144
1145 /* xen_vcpu_setup managed to place the vcpu_info within the
1146 * percpu area for all cpus, so make use of it. Note that for
1147 * PVH we want to use native IRQ mechanism. */
1148 if (have_vcpu_info_placement && !xen_pvh_domain()) {
1149 pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
1150 pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct);
1151 pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
1152 pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
1153 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
1154 }
1155}
1156
1157static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
1158 unsigned long addr, unsigned len)
1159{
1160 char *start, *end, *reloc;
1161 unsigned ret;
1162
1163 start = end = reloc = NULL;
1164
1165#define SITE(op, x) \
1166 case PARAVIRT_PATCH(op.x): \
1167 if (have_vcpu_info_placement) { \
1168 start = (char *)xen_##x##_direct; \
1169 end = xen_##x##_direct_end; \
1170 reloc = xen_##x##_direct_reloc; \
1171 } \
1172 goto patch_site
1173
1174 switch (type) {
1175 SITE(pv_irq_ops, irq_enable);
1176 SITE(pv_irq_ops, irq_disable);
1177 SITE(pv_irq_ops, save_fl);
1178 SITE(pv_irq_ops, restore_fl);
1179#undef SITE
1180
1181 patch_site:
1182 if (start == NULL || (end-start) > len)
1183 goto default_patch;
1184
1185 ret = paravirt_patch_insns(insnbuf, len, start, end);
1186
1187 /* Note: because reloc is assigned from something that
1188 appears to be an array, gcc assumes it's non-null,
1189 but doesn't know its relationship with start and
1190 end. */
1191 if (reloc > start && reloc < end) {
1192 int reloc_off = reloc - start;
1193 long *relocp = (long *)(insnbuf + reloc_off);
1194 long delta = start - (char *)addr;
1195
1196 *relocp += delta;
1197 }
1198 break;
1199
1200 default_patch:
1201 default:
1202 ret = paravirt_patch_default(type, clobbers, insnbuf,
1203 addr, len);
1204 break;
1205 }
1206
1207 return ret;
1208}
1209
1210static const struct pv_info xen_info __initconst = {
1211 .paravirt_enabled = 1,
1212 .shared_kernel_pmd = 0,
1213
1214#ifdef CONFIG_X86_64
1215 .extra_user_64bit_cs = FLAT_USER_CS64,
1216#endif
1217
1218 .name = "Xen",
1219};
1220
1221static const struct pv_init_ops xen_init_ops __initconst = {
1222 .patch = xen_patch,
1223};
1224
1225static const struct pv_cpu_ops xen_cpu_ops __initconst = {
1226 .cpuid = xen_cpuid,
1227
1228 .set_debugreg = xen_set_debugreg,
1229 .get_debugreg = xen_get_debugreg,
1230
1231 .clts = xen_clts,
1232
1233 .read_cr0 = xen_read_cr0,
1234 .write_cr0 = xen_write_cr0,
1235
1236 .read_cr4 = native_read_cr4,
1237 .read_cr4_safe = native_read_cr4_safe,
1238 .write_cr4 = xen_write_cr4,
1239
1240#ifdef CONFIG_X86_64
1241 .read_cr8 = xen_read_cr8,
1242 .write_cr8 = xen_write_cr8,
1243#endif
1244
1245 .wbinvd = native_wbinvd,
1246
1247 .read_msr = native_read_msr_safe,
1248 .write_msr = xen_write_msr_safe,
1249
1250 .read_tsc = native_read_tsc,
1251 .read_pmc = native_read_pmc,
1252
1253 .read_tscp = native_read_tscp,
1254
1255 .iret = xen_iret,
1256 .irq_enable_sysexit = xen_sysexit,
1257#ifdef CONFIG_X86_64
1258 .usergs_sysret32 = xen_sysret32,
1259 .usergs_sysret64 = xen_sysret64,
1260#endif
1261
1262 .load_tr_desc = paravirt_nop,
1263 .set_ldt = xen_set_ldt,
1264 .load_gdt = xen_load_gdt,
1265 .load_idt = xen_load_idt,
1266 .load_tls = xen_load_tls,
1267#ifdef CONFIG_X86_64
1268 .load_gs_index = xen_load_gs_index,
1269#endif
1270
1271 .alloc_ldt = xen_alloc_ldt,
1272 .free_ldt = xen_free_ldt,
1273
1274 .store_idt = native_store_idt,
1275 .store_tr = xen_store_tr,
1276
1277 .write_ldt_entry = xen_write_ldt_entry,
1278 .write_gdt_entry = xen_write_gdt_entry,
1279 .write_idt_entry = xen_write_idt_entry,
1280 .load_sp0 = xen_load_sp0,
1281
1282 .set_iopl_mask = xen_set_iopl_mask,
1283 .io_delay = xen_io_delay,
1284
1285 /* Xen takes care of %gs when switching to usermode for us */
1286 .swapgs = paravirt_nop,
1287
1288 .start_context_switch = paravirt_start_context_switch,
1289 .end_context_switch = xen_end_context_switch,
1290};
1291
1292static const struct pv_apic_ops xen_apic_ops __initconst = {
1293#ifdef CONFIG_X86_LOCAL_APIC
1294 .startup_ipi_hook = paravirt_nop,
1295#endif
1296};
1297
1298static void xen_reboot(int reason)
1299{
1300 struct sched_shutdown r = { .reason = reason };
1301
1302 if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
1303 BUG();
1304}
1305
1306static void xen_restart(char *msg)
1307{
1308 xen_reboot(SHUTDOWN_reboot);
1309}
1310
1311static void xen_emergency_restart(void)
1312{
1313 xen_reboot(SHUTDOWN_reboot);
1314}
1315
1316static void xen_machine_halt(void)
1317{
1318 xen_reboot(SHUTDOWN_poweroff);
1319}
1320
1321static void xen_machine_power_off(void)
1322{
1323 if (pm_power_off)
1324 pm_power_off();
1325 xen_reboot(SHUTDOWN_poweroff);
1326}
1327
1328static void xen_crash_shutdown(struct pt_regs *regs)
1329{
1330 xen_reboot(SHUTDOWN_crash);
1331}
1332
1333static int
1334xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
1335{
1336 xen_reboot(SHUTDOWN_crash);
1337 return NOTIFY_DONE;
1338}
1339
1340static struct notifier_block xen_panic_block = {
1341 .notifier_call= xen_panic_event,
1342 .priority = INT_MIN
1343};
1344
1345int xen_panic_handler_init(void)
1346{
1347 atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block);
1348 return 0;
1349}
1350
1351static const struct machine_ops xen_machine_ops __initconst = {
1352 .restart = xen_restart,
1353 .halt = xen_machine_halt,
1354 .power_off = xen_machine_power_off,
1355 .shutdown = xen_machine_halt,
1356 .crash_shutdown = xen_crash_shutdown,
1357 .emergency_restart = xen_emergency_restart,
1358};
1359
1360static void __init xen_boot_params_init_edd(void)
1361{
1362#if IS_ENABLED(CONFIG_EDD)
1363 struct xen_platform_op op;
1364 struct edd_info *edd_info;
1365 u32 *mbr_signature;
1366 unsigned nr;
1367 int ret;
1368
1369 edd_info = boot_params.eddbuf;
1370 mbr_signature = boot_params.edd_mbr_sig_buffer;
1371
1372 op.cmd = XENPF_firmware_info;
1373
1374 op.u.firmware_info.type = XEN_FW_DISK_INFO;
1375 for (nr = 0; nr < EDDMAXNR; nr++) {
1376 struct edd_info *info = edd_info + nr;
1377
1378 op.u.firmware_info.index = nr;
1379 info->params.length = sizeof(info->params);
1380 set_xen_guest_handle(op.u.firmware_info.u.disk_info.edd_params,
1381 &info->params);
1382 ret = HYPERVISOR_dom0_op(&op);
1383 if (ret)
1384 break;
1385
1386#define C(x) info->x = op.u.firmware_info.u.disk_info.x
1387 C(device);
1388 C(version);
1389 C(interface_support);
1390 C(legacy_max_cylinder);
1391 C(legacy_max_head);
1392 C(legacy_sectors_per_track);
1393#undef C
1394 }
1395 boot_params.eddbuf_entries = nr;
1396
1397 op.u.firmware_info.type = XEN_FW_DISK_MBR_SIGNATURE;
1398 for (nr = 0; nr < EDD_MBR_SIG_MAX; nr++) {
1399 op.u.firmware_info.index = nr;
1400 ret = HYPERVISOR_dom0_op(&op);
1401 if (ret)
1402 break;
1403 mbr_signature[nr] = op.u.firmware_info.u.disk_mbr_signature.mbr_signature;
1404 }
1405 boot_params.edd_mbr_sig_buf_entries = nr;
1406#endif
1407}
1408
1409/*
1410 * Set up the GDT and segment registers for -fstack-protector. Until
1411 * we do this, we have to be careful not to call any stack-protected
1412 * function, which is most of the kernel.
1413 *
1414 * Note, that it is __ref because the only caller of this after init
1415 * is PVH which is not going to use xen_load_gdt_boot or other
1416 * __init functions.
1417 */
1418static void __ref xen_setup_gdt(int cpu)
1419{
1420 if (xen_feature(XENFEAT_auto_translated_physmap)) {
1421#ifdef CONFIG_X86_64
1422 unsigned long dummy;
1423
1424 load_percpu_segment(cpu); /* We need to access per-cpu area */
1425 switch_to_new_gdt(cpu); /* GDT and GS set */
1426
1427 /* We are switching of the Xen provided GDT to our HVM mode
1428 * GDT. The new GDT has __KERNEL_CS with CS.L = 1
1429 * and we are jumping to reload it.
1430 */
1431 asm volatile ("pushq %0\n"
1432 "leaq 1f(%%rip),%0\n"
1433 "pushq %0\n"
1434 "lretq\n"
1435 "1:\n"
1436 : "=&r" (dummy) : "0" (__KERNEL_CS));
1437
1438 /*
1439 * While not needed, we also set the %es, %ds, and %fs
1440 * to zero. We don't care about %ss as it is NULL.
1441 * Strictly speaking this is not needed as Xen zeros those
1442 * out (and also MSR_FS_BASE, MSR_GS_BASE, MSR_KERNEL_GS_BASE)
1443 *
1444 * Linux zeros them in cpu_init() and in secondary_startup_64
1445 * (for BSP).
1446 */
1447 loadsegment(es, 0);
1448 loadsegment(ds, 0);
1449 loadsegment(fs, 0);
1450#else
1451 /* PVH: TODO Implement. */
1452 BUG();
1453#endif
1454 return; /* PVH does not need any PV GDT ops. */
1455 }
1456 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
1457 pv_cpu_ops.load_gdt = xen_load_gdt_boot;
1458
1459 setup_stack_canary_segment(0);
1460 switch_to_new_gdt(0);
1461
1462 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry;
1463 pv_cpu_ops.load_gdt = xen_load_gdt;
1464}
1465
1466/*
1467 * A PV guest starts with default flags that are not set for PVH, set them
1468 * here asap.
1469 */
1470static void xen_pvh_set_cr_flags(int cpu)
1471{
1472
1473 /* Some of these are setup in 'secondary_startup_64'. The others:
1474 * X86_CR0_TS, X86_CR0_PE, X86_CR0_ET are set by Xen for HVM guests
1475 * (which PVH shared codepaths), while X86_CR0_PG is for PVH. */
1476 write_cr0(read_cr0() | X86_CR0_MP | X86_CR0_NE | X86_CR0_WP | X86_CR0_AM);
1477
1478 if (!cpu)
1479 return;
1480 /*
1481 * For BSP, PSE PGE are set in probe_page_size_mask(), for APs
1482 * set them here. For all, OSFXSR OSXMMEXCPT are set in fpu_init.
1483 */
1484 if (cpu_has_pse)
1485 set_in_cr4(X86_CR4_PSE);
1486
1487 if (cpu_has_pge)
1488 set_in_cr4(X86_CR4_PGE);
1489}
1490
1491/*
1492 * Note, that it is ref - because the only caller of this after init
1493 * is PVH which is not going to use xen_load_gdt_boot or other
1494 * __init functions.
1495 */
1496void __ref xen_pvh_secondary_vcpu_init(int cpu)
1497{
1498 xen_setup_gdt(cpu);
1499 xen_pvh_set_cr_flags(cpu);
1500}
1501
1502static void __init xen_pvh_early_guest_init(void)
1503{
1504 if (!xen_feature(XENFEAT_auto_translated_physmap))
1505 return;
1506
1507 if (!xen_feature(XENFEAT_hvm_callback_vector))
1508 return;
1509
1510 xen_have_vector_callback = 1;
1511 xen_pvh_set_cr_flags(0);
1512
1513#ifdef CONFIG_X86_32
1514 BUG(); /* PVH: Implement proper support. */
1515#endif
1516}
1517
1518/* First C function to be called on Xen boot */
1519asmlinkage __visible void __init xen_start_kernel(void)
1520{
1521 struct physdev_set_iopl set_iopl;
1522 int rc;
1523
1524 if (!xen_start_info)
1525 return;
1526
1527 xen_domain_type = XEN_PV_DOMAIN;
1528
1529 xen_setup_features();
1530 xen_pvh_early_guest_init();
1531 xen_setup_machphys_mapping();
1532
1533 /* Install Xen paravirt ops */
1534 pv_info = xen_info;
1535 pv_init_ops = xen_init_ops;
1536 pv_apic_ops = xen_apic_ops;
1537 if (!xen_pvh_domain())
1538 pv_cpu_ops = xen_cpu_ops;
1539
1540 if (xen_feature(XENFEAT_auto_translated_physmap))
1541 x86_init.resources.memory_setup = xen_auto_xlated_memory_setup;
1542 else
1543 x86_init.resources.memory_setup = xen_memory_setup;
1544 x86_init.oem.arch_setup = xen_arch_setup;
1545 x86_init.oem.banner = xen_banner;
1546
1547 xen_init_time_ops();
1548
1549 /*
1550 * Set up some pagetable state before starting to set any ptes.
1551 */
1552
1553 xen_init_mmu_ops();
1554
1555 /* Prevent unwanted bits from being set in PTEs. */
1556 __supported_pte_mask &= ~_PAGE_GLOBAL;
1557#if 0
1558 if (!xen_initial_domain())
1559#endif
1560 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
1561
1562 __supported_pte_mask |= _PAGE_IOMAP;
1563
1564 /*
1565 * Prevent page tables from being allocated in highmem, even
1566 * if CONFIG_HIGHPTE is enabled.
1567 */
1568 __userpte_alloc_gfp &= ~__GFP_HIGHMEM;
1569
1570 /* Work out if we support NX */
1571 x86_configure_nx();
1572
1573 /* Get mfn list */
1574 xen_build_dynamic_phys_to_machine();
1575
1576 /*
1577 * Set up kernel GDT and segment registers, mainly so that
1578 * -fstack-protector code can be executed.
1579 */
1580 xen_setup_gdt(0);
1581
1582 xen_init_irq_ops();
1583 xen_init_cpuid_mask();
1584
1585#ifdef CONFIG_X86_LOCAL_APIC
1586 /*
1587 * set up the basic apic ops.
1588 */
1589 set_xen_basic_apic_ops();
1590#endif
1591
1592 if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
1593 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
1594 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
1595 }
1596
1597 machine_ops = xen_machine_ops;
1598
1599 /*
1600 * The only reliable way to retain the initial address of the
1601 * percpu gdt_page is to remember it here, so we can go and
1602 * mark it RW later, when the initial percpu area is freed.
1603 */
1604 xen_initial_gdt = &per_cpu(gdt_page, 0);
1605
1606 xen_smp_init();
1607
1608#ifdef CONFIG_ACPI_NUMA
1609 /*
1610 * The pages we from Xen are not related to machine pages, so
1611 * any NUMA information the kernel tries to get from ACPI will
1612 * be meaningless. Prevent it from trying.
1613 */
1614 acpi_numa = -1;
1615#endif
1616#ifdef CONFIG_X86_PAT
1617 /*
1618 * For right now disable the PAT. We should remove this once
1619 * git commit 8eaffa67b43e99ae581622c5133e20b0f48bcef1
1620 * (xen/pat: Disable PAT support for now) is reverted.
1621 */
1622 pat_enabled = 0;
1623#endif
1624 /* Don't do the full vcpu_info placement stuff until we have a
1625 possible map and a non-dummy shared_info. */
1626 per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1627
1628 local_irq_disable();
1629 early_boot_irqs_disabled = true;
1630
1631 xen_raw_console_write("mapping kernel into physical memory\n");
1632 xen_setup_kernel_pagetable((pgd_t *)xen_start_info->pt_base, xen_start_info->nr_pages);
1633
1634 /* Allocate and initialize top and mid mfn levels for p2m structure */
1635 xen_build_mfn_list_list();
1636
1637 /* keep using Xen gdt for now; no urgent need to change it */
1638
1639#ifdef CONFIG_X86_32
1640 pv_info.kernel_rpl = 1;
1641 if (xen_feature(XENFEAT_supervisor_mode_kernel))
1642 pv_info.kernel_rpl = 0;
1643#else
1644 pv_info.kernel_rpl = 0;
1645#endif
1646 /* set the limit of our address space */
1647 xen_reserve_top();
1648
1649 /* PVH: runs at default kernel iopl of 0 */
1650 if (!xen_pvh_domain()) {
1651 /*
1652 * We used to do this in xen_arch_setup, but that is too late
1653 * on AMD were early_cpu_init (run before ->arch_setup()) calls
1654 * early_amd_init which pokes 0xcf8 port.
1655 */
1656 set_iopl.iopl = 1;
1657 rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
1658 if (rc != 0)
1659 xen_raw_printk("physdev_op failed %d\n", rc);
1660 }
1661
1662#ifdef CONFIG_X86_32
1663 /* set up basic CPUID stuff */
1664 cpu_detect(&new_cpu_data);
1665 set_cpu_cap(&new_cpu_data, X86_FEATURE_FPU);
1666 new_cpu_data.wp_works_ok = 1;
1667 new_cpu_data.x86_capability[0] = cpuid_edx(1);
1668#endif
1669
1670 /* Poke various useful things into boot_params */
1671 boot_params.hdr.type_of_loader = (9 << 4) | 0;
1672 boot_params.hdr.ramdisk_image = xen_start_info->mod_start
1673 ? __pa(xen_start_info->mod_start) : 0;
1674 boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
1675 boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
1676
1677 if (!xen_initial_domain()) {
1678 add_preferred_console("xenboot", 0, NULL);
1679 add_preferred_console("tty", 0, NULL);
1680 add_preferred_console("hvc", 0, NULL);
1681 if (pci_xen)
1682 x86_init.pci.arch_init = pci_xen_init;
1683 } else {
1684 const struct dom0_vga_console_info *info =
1685 (void *)((char *)xen_start_info +
1686 xen_start_info->console.dom0.info_off);
1687 struct xen_platform_op op = {
1688 .cmd = XENPF_firmware_info,
1689 .interface_version = XENPF_INTERFACE_VERSION,
1690 .u.firmware_info.type = XEN_FW_KBD_SHIFT_FLAGS,
1691 };
1692
1693 xen_init_vga(info, xen_start_info->console.dom0.info_size);
1694 xen_start_info->console.domU.mfn = 0;
1695 xen_start_info->console.domU.evtchn = 0;
1696
1697 if (HYPERVISOR_dom0_op(&op) == 0)
1698 boot_params.kbd_status = op.u.firmware_info.u.kbd_shift_flags;
1699
1700 xen_init_apic();
1701
1702 /* Make sure ACS will be enabled */
1703 pci_request_acs();
1704
1705 xen_acpi_sleep_register();
1706
1707 /* Avoid searching for BIOS MP tables */
1708 x86_init.mpparse.find_smp_config = x86_init_noop;
1709 x86_init.mpparse.get_smp_config = x86_init_uint_noop;
1710
1711 xen_boot_params_init_edd();
1712 }
1713#ifdef CONFIG_PCI
1714 /* PCI BIOS service won't work from a PV guest. */
1715 pci_probe &= ~PCI_PROBE_BIOS;
1716#endif
1717 xen_raw_console_write("about to get started...\n");
1718
1719 xen_setup_runstate_info(0);
1720
1721 xen_efi_init();
1722
1723 /* Start the world */
1724#ifdef CONFIG_X86_32
1725 i386_start_kernel();
1726#else
1727 x86_64_start_reservations((char *)__pa_symbol(&boot_params));
1728#endif
1729}
1730
1731void __ref xen_hvm_init_shared_info(void)
1732{
1733 int cpu;
1734 struct xen_add_to_physmap xatp;
1735 static struct shared_info *shared_info_page = 0;
1736
1737 if (!shared_info_page)
1738 shared_info_page = (struct shared_info *)
1739 extend_brk(PAGE_SIZE, PAGE_SIZE);
1740 xatp.domid = DOMID_SELF;
1741 xatp.idx = 0;
1742 xatp.space = XENMAPSPACE_shared_info;
1743 xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
1744 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
1745 BUG();
1746
1747 HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
1748
1749 /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
1750 * page, we use it in the event channel upcall and in some pvclock
1751 * related functions. We don't need the vcpu_info placement
1752 * optimizations because we don't use any pv_mmu or pv_irq op on
1753 * HVM.
1754 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
1755 * online but xen_hvm_init_shared_info is run at resume time too and
1756 * in that case multiple vcpus might be online. */
1757 for_each_online_cpu(cpu) {
1758 /* Leave it to be NULL. */
1759 if (cpu >= MAX_VIRT_CPUS)
1760 continue;
1761 per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
1762 }
1763}
1764
1765#ifdef CONFIG_XEN_PVHVM
1766static void __init init_hvm_pv_info(void)
1767{
1768 int major, minor;
1769 uint32_t eax, ebx, ecx, edx, pages, msr, base;
1770 u64 pfn;
1771
1772 base = xen_cpuid_base();
1773 cpuid(base + 1, &eax, &ebx, &ecx, &edx);
1774
1775 major = eax >> 16;
1776 minor = eax & 0xffff;
1777 printk(KERN_INFO "Xen version %d.%d.\n", major, minor);
1778
1779 cpuid(base + 2, &pages, &msr, &ecx, &edx);
1780
1781 pfn = __pa(hypercall_page);
1782 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
1783
1784 xen_setup_features();
1785
1786 pv_info.name = "Xen HVM";
1787
1788 xen_domain_type = XEN_HVM_DOMAIN;
1789}
1790
1791static int xen_hvm_cpu_notify(struct notifier_block *self, unsigned long action,
1792 void *hcpu)
1793{
1794 int cpu = (long)hcpu;
1795 switch (action) {
1796 case CPU_UP_PREPARE:
1797 xen_vcpu_setup(cpu);
1798 if (xen_have_vector_callback) {
1799 if (xen_feature(XENFEAT_hvm_safe_pvclock))
1800 xen_setup_timer(cpu);
1801 }
1802 break;
1803 default:
1804 break;
1805 }
1806 return NOTIFY_OK;
1807}
1808
1809static struct notifier_block xen_hvm_cpu_notifier = {
1810 .notifier_call = xen_hvm_cpu_notify,
1811};
1812
1813static void __init xen_hvm_guest_init(void)
1814{
1815 init_hvm_pv_info();
1816
1817 xen_hvm_init_shared_info();
1818
1819 xen_panic_handler_init();
1820
1821 if (xen_feature(XENFEAT_hvm_callback_vector))
1822 xen_have_vector_callback = 1;
1823 xen_hvm_smp_init();
1824 register_cpu_notifier(&xen_hvm_cpu_notifier);
1825 xen_unplug_emulated_devices();
1826 x86_init.irqs.intr_init = xen_init_IRQ;
1827 xen_hvm_init_time_ops();
1828 xen_hvm_init_mmu_ops();
1829}
1830
1831static bool xen_nopv = false;
1832static __init int xen_parse_nopv(char *arg)
1833{
1834 xen_nopv = true;
1835 return 0;
1836}
1837early_param("xen_nopv", xen_parse_nopv);
1838
1839static uint32_t __init xen_hvm_platform(void)
1840{
1841 if (xen_nopv)
1842 return 0;
1843
1844 if (xen_pv_domain())
1845 return 0;
1846
1847 return xen_cpuid_base();
1848}
1849
1850bool xen_hvm_need_lapic(void)
1851{
1852 if (xen_nopv)
1853 return false;
1854 if (xen_pv_domain())
1855 return false;
1856 if (!xen_hvm_domain())
1857 return false;
1858 if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
1859 return false;
1860 return true;
1861}
1862EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
1863
1864const struct hypervisor_x86 x86_hyper_xen_hvm __refconst = {
1865 .name = "Xen HVM",
1866 .detect = xen_hvm_platform,
1867 .init_platform = xen_hvm_guest_init,
1868 .x2apic_available = xen_x2apic_para_available,
1869};
1870EXPORT_SYMBOL(x86_hyper_xen_hvm);
1871#endif
1872