1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Core of Xen paravirt_ops implementation.
4 *
5 * This file contains the xen_paravirt_ops structure itself, and the
6 * implementations for:
7 * - privileged instructions
8 * - interrupt flags
9 * - segment operations
10 * - booting and setup
11 *
12 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
13 */
14
15 #include <linux/cpu.h>
16 #include <linux/kernel.h>
17 #include <linux/init.h>
18 #include <linux/smp.h>
19 #include <linux/preempt.h>
20 #include <linux/hardirq.h>
21 #include <linux/percpu.h>
22 #include <linux/delay.h>
23 #include <linux/start_kernel.h>
24 #include <linux/sched.h>
25 #include <linux/kprobes.h>
26 #include <linux/bootmem.h>
27 #include <linux/export.h>
28 #include <linux/mm.h>
29 #include <linux/page-flags.h>
30 #include <linux/highmem.h>
31 #include <linux/console.h>
32 #include <linux/pci.h>
33 #include <linux/gfp.h>
34 #include <linux/memblock.h>
35 #include <linux/edd.h>
36 #include <linux/frame.h>
37
38 #include <xen/xen.h>
39 #include <xen/events.h>
40 #include <xen/interface/xen.h>
41 #include <xen/interface/version.h>
42 #include <xen/interface/physdev.h>
43 #include <xen/interface/vcpu.h>
44 #include <xen/interface/memory.h>
45 #include <xen/interface/nmi.h>
46 #include <xen/interface/xen-mca.h>
47 #include <xen/features.h>
48 #include <xen/page.h>
49 #include <xen/hvc-console.h>
50 #include <xen/acpi.h>
51
52 #include <asm/paravirt.h>
53 #include <asm/apic.h>
54 #include <asm/page.h>
55 #include <asm/xen/pci.h>
56 #include <asm/xen/hypercall.h>
57 #include <asm/xen/hypervisor.h>
58 #include <asm/xen/cpuid.h>
59 #include <asm/fixmap.h>
60 #include <asm/processor.h>
61 #include <asm/proto.h>
62 #include <asm/msr-index.h>
63 #include <asm/traps.h>
64 #include <asm/setup.h>
65 #include <asm/desc.h>
66 #include <asm/pgalloc.h>
67 #include <asm/pgtable.h>
68 #include <asm/tlbflush.h>
69 #include <asm/reboot.h>
70 #include <asm/stackprotector.h>
71 #include <asm/hypervisor.h>
72 #include <asm/mach_traps.h>
73 #include <asm/mwait.h>
74 #include <asm/pci_x86.h>
75 #include <asm/cpu.h>
76
77 #ifdef CONFIG_ACPI
78 #include <linux/acpi.h>
79 #include <asm/acpi.h>
80 #include <acpi/pdc_intel.h>
81 #include <acpi/processor.h>
82 #include <xen/interface/platform.h>
83 #endif
84
85 #include "xen-ops.h"
86 #include "mmu.h"
87 #include "smp.h"
88 #include "multicalls.h"
89 #include "pmu.h"
90
91 #include "../kernel/cpu/cpu.h" /* get_cpu_cap() */
92
93 void *xen_initial_gdt;
94
95 static int xen_cpu_up_prepare_pv(unsigned int cpu);
96 static int xen_cpu_dead_pv(unsigned int cpu);
97
98 struct tls_descs {
99 struct desc_struct desc[3];
100 };
101
102 /*
103 * Updating the 3 TLS descriptors in the GDT on every task switch is
104 * surprisingly expensive so we avoid updating them if they haven't
105 * changed. Since Xen writes different descriptors than the one
106 * passed in the update_descriptor hypercall we keep shadow copies to
107 * compare against.
108 */
109 static DEFINE_PER_CPU(struct tls_descs, shadow_tls_desc);
110
xen_banner(void)111 static void __init xen_banner(void)
112 {
113 unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
114 struct xen_extraversion extra;
115 HYPERVISOR_xen_version(XENVER_extraversion, &extra);
116
117 pr_info("Booting paravirtualized kernel on %s\n", pv_info.name);
118 printk(KERN_INFO "Xen version: %d.%d%s%s\n",
119 version >> 16, version & 0xffff, extra.extraversion,
120 xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
121 }
122
xen_pv_init_platform(void)123 static void __init xen_pv_init_platform(void)
124 {
125 populate_extra_pte(fix_to_virt(FIX_PARAVIRT_BOOTMAP));
126
127 set_fixmap(FIX_PARAVIRT_BOOTMAP, xen_start_info->shared_info);
128 HYPERVISOR_shared_info = (void *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
129
130 /* xen clock uses per-cpu vcpu_info, need to init it for boot cpu */
131 xen_vcpu_info_reset(0);
132
133 /* pvclock is in shared info area */
134 xen_init_time_ops();
135 }
136
xen_pv_guest_late_init(void)137 static void __init xen_pv_guest_late_init(void)
138 {
139 #ifndef CONFIG_SMP
140 /* Setup shared vcpu info for non-smp configurations */
141 xen_setup_vcpu_info_placement();
142 #endif
143 }
144
145 /* Check if running on Xen version (major, minor) or later */
146 bool
xen_running_on_version_or_later(unsigned int major,unsigned int minor)147 xen_running_on_version_or_later(unsigned int major, unsigned int minor)
148 {
149 unsigned int version;
150
151 if (!xen_domain())
152 return false;
153
154 version = HYPERVISOR_xen_version(XENVER_version, NULL);
155 if ((((version >> 16) == major) && ((version & 0xffff) >= minor)) ||
156 ((version >> 16) > major))
157 return true;
158 return false;
159 }
160
161 static __read_mostly unsigned int cpuid_leaf5_ecx_val;
162 static __read_mostly unsigned int cpuid_leaf5_edx_val;
163
xen_cpuid(unsigned int * ax,unsigned int * bx,unsigned int * cx,unsigned int * dx)164 static void xen_cpuid(unsigned int *ax, unsigned int *bx,
165 unsigned int *cx, unsigned int *dx)
166 {
167 unsigned maskebx = ~0;
168
169 /*
170 * Mask out inconvenient features, to try and disable as many
171 * unsupported kernel subsystems as possible.
172 */
173 switch (*ax) {
174 case CPUID_MWAIT_LEAF:
175 /* Synthesize the values.. */
176 *ax = 0;
177 *bx = 0;
178 *cx = cpuid_leaf5_ecx_val;
179 *dx = cpuid_leaf5_edx_val;
180 return;
181
182 case 0xb:
183 /* Suppress extended topology stuff */
184 maskebx = 0;
185 break;
186 }
187
188 asm(XEN_EMULATE_PREFIX "cpuid"
189 : "=a" (*ax),
190 "=b" (*bx),
191 "=c" (*cx),
192 "=d" (*dx)
193 : "0" (*ax), "2" (*cx));
194
195 *bx &= maskebx;
196 }
197 STACK_FRAME_NON_STANDARD(xen_cpuid); /* XEN_EMULATE_PREFIX */
198
xen_check_mwait(void)199 static bool __init xen_check_mwait(void)
200 {
201 #ifdef CONFIG_ACPI
202 struct xen_platform_op op = {
203 .cmd = XENPF_set_processor_pminfo,
204 .u.set_pminfo.id = -1,
205 .u.set_pminfo.type = XEN_PM_PDC,
206 };
207 uint32_t buf[3];
208 unsigned int ax, bx, cx, dx;
209 unsigned int mwait_mask;
210
211 /* We need to determine whether it is OK to expose the MWAIT
212 * capability to the kernel to harvest deeper than C3 states from ACPI
213 * _CST using the processor_harvest_xen.c module. For this to work, we
214 * need to gather the MWAIT_LEAF values (which the cstate.c code
215 * checks against). The hypervisor won't expose the MWAIT flag because
216 * it would break backwards compatibility; so we will find out directly
217 * from the hardware and hypercall.
218 */
219 if (!xen_initial_domain())
220 return false;
221
222 /*
223 * When running under platform earlier than Xen4.2, do not expose
224 * mwait, to avoid the risk of loading native acpi pad driver
225 */
226 if (!xen_running_on_version_or_later(4, 2))
227 return false;
228
229 ax = 1;
230 cx = 0;
231
232 native_cpuid(&ax, &bx, &cx, &dx);
233
234 mwait_mask = (1 << (X86_FEATURE_EST % 32)) |
235 (1 << (X86_FEATURE_MWAIT % 32));
236
237 if ((cx & mwait_mask) != mwait_mask)
238 return false;
239
240 /* We need to emulate the MWAIT_LEAF and for that we need both
241 * ecx and edx. The hypercall provides only partial information.
242 */
243
244 ax = CPUID_MWAIT_LEAF;
245 bx = 0;
246 cx = 0;
247 dx = 0;
248
249 native_cpuid(&ax, &bx, &cx, &dx);
250
251 /* Ask the Hypervisor whether to clear ACPI_PDC_C_C2C3_FFH. If so,
252 * don't expose MWAIT_LEAF and let ACPI pick the IOPORT version of C3.
253 */
254 buf[0] = ACPI_PDC_REVISION_ID;
255 buf[1] = 1;
256 buf[2] = (ACPI_PDC_C_CAPABILITY_SMP | ACPI_PDC_EST_CAPABILITY_SWSMP);
257
258 set_xen_guest_handle(op.u.set_pminfo.pdc, buf);
259
260 if ((HYPERVISOR_platform_op(&op) == 0) &&
261 (buf[2] & (ACPI_PDC_C_C1_FFH | ACPI_PDC_C_C2C3_FFH))) {
262 cpuid_leaf5_ecx_val = cx;
263 cpuid_leaf5_edx_val = dx;
264 }
265 return true;
266 #else
267 return false;
268 #endif
269 }
270
xen_check_xsave(void)271 static bool __init xen_check_xsave(void)
272 {
273 unsigned int cx, xsave_mask;
274
275 cx = cpuid_ecx(1);
276
277 xsave_mask = (1 << (X86_FEATURE_XSAVE % 32)) |
278 (1 << (X86_FEATURE_OSXSAVE % 32));
279
280 /* Xen will set CR4.OSXSAVE if supported and not disabled by force */
281 return (cx & xsave_mask) == xsave_mask;
282 }
283
xen_init_capabilities(void)284 static void __init xen_init_capabilities(void)
285 {
286 setup_force_cpu_cap(X86_FEATURE_XENPV);
287 setup_clear_cpu_cap(X86_FEATURE_DCA);
288 setup_clear_cpu_cap(X86_FEATURE_APERFMPERF);
289 setup_clear_cpu_cap(X86_FEATURE_MTRR);
290 setup_clear_cpu_cap(X86_FEATURE_ACC);
291 setup_clear_cpu_cap(X86_FEATURE_X2APIC);
292 setup_clear_cpu_cap(X86_FEATURE_SME);
293
294 /*
295 * Xen PV would need some work to support PCID: CR3 handling as well
296 * as xen_flush_tlb_others() would need updating.
297 */
298 setup_clear_cpu_cap(X86_FEATURE_PCID);
299
300 if (!xen_initial_domain())
301 setup_clear_cpu_cap(X86_FEATURE_ACPI);
302
303 if (xen_check_mwait())
304 setup_force_cpu_cap(X86_FEATURE_MWAIT);
305 else
306 setup_clear_cpu_cap(X86_FEATURE_MWAIT);
307
308 if (!xen_check_xsave()) {
309 setup_clear_cpu_cap(X86_FEATURE_XSAVE);
310 setup_clear_cpu_cap(X86_FEATURE_OSXSAVE);
311 }
312 }
313
xen_set_debugreg(int reg,unsigned long val)314 static void xen_set_debugreg(int reg, unsigned long val)
315 {
316 HYPERVISOR_set_debugreg(reg, val);
317 }
318
xen_get_debugreg(int reg)319 static unsigned long xen_get_debugreg(int reg)
320 {
321 return HYPERVISOR_get_debugreg(reg);
322 }
323
xen_end_context_switch(struct task_struct * next)324 static void xen_end_context_switch(struct task_struct *next)
325 {
326 xen_mc_flush();
327 paravirt_end_context_switch(next);
328 }
329
xen_store_tr(void)330 static unsigned long xen_store_tr(void)
331 {
332 return 0;
333 }
334
335 /*
336 * Set the page permissions for a particular virtual address. If the
337 * address is a vmalloc mapping (or other non-linear mapping), then
338 * find the linear mapping of the page and also set its protections to
339 * match.
340 */
set_aliased_prot(void * v,pgprot_t prot)341 static void set_aliased_prot(void *v, pgprot_t prot)
342 {
343 int level;
344 pte_t *ptep;
345 pte_t pte;
346 unsigned long pfn;
347 struct page *page;
348 unsigned char dummy;
349
350 ptep = lookup_address((unsigned long)v, &level);
351 BUG_ON(ptep == NULL);
352
353 pfn = pte_pfn(*ptep);
354 page = pfn_to_page(pfn);
355
356 pte = pfn_pte(pfn, prot);
357
358 /*
359 * Careful: update_va_mapping() will fail if the virtual address
360 * we're poking isn't populated in the page tables. We don't
361 * need to worry about the direct map (that's always in the page
362 * tables), but we need to be careful about vmap space. In
363 * particular, the top level page table can lazily propagate
364 * entries between processes, so if we've switched mms since we
365 * vmapped the target in the first place, we might not have the
366 * top-level page table entry populated.
367 *
368 * We disable preemption because we want the same mm active when
369 * we probe the target and when we issue the hypercall. We'll
370 * have the same nominal mm, but if we're a kernel thread, lazy
371 * mm dropping could change our pgd.
372 *
373 * Out of an abundance of caution, this uses __get_user() to fault
374 * in the target address just in case there's some obscure case
375 * in which the target address isn't readable.
376 */
377
378 preempt_disable();
379
380 probe_kernel_read(&dummy, v, 1);
381
382 if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
383 BUG();
384
385 if (!PageHighMem(page)) {
386 void *av = __va(PFN_PHYS(pfn));
387
388 if (av != v)
389 if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
390 BUG();
391 } else
392 kmap_flush_unused();
393
394 preempt_enable();
395 }
396
xen_alloc_ldt(struct desc_struct * ldt,unsigned entries)397 static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
398 {
399 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
400 int i;
401
402 /*
403 * We need to mark the all aliases of the LDT pages RO. We
404 * don't need to call vm_flush_aliases(), though, since that's
405 * only responsible for flushing aliases out the TLBs, not the
406 * page tables, and Xen will flush the TLB for us if needed.
407 *
408 * To avoid confusing future readers: none of this is necessary
409 * to load the LDT. The hypervisor only checks this when the
410 * LDT is faulted in due to subsequent descriptor access.
411 */
412
413 for (i = 0; i < entries; i += entries_per_page)
414 set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
415 }
416
xen_free_ldt(struct desc_struct * ldt,unsigned entries)417 static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
418 {
419 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
420 int i;
421
422 for (i = 0; i < entries; i += entries_per_page)
423 set_aliased_prot(ldt + i, PAGE_KERNEL);
424 }
425
xen_set_ldt(const void * addr,unsigned entries)426 static void xen_set_ldt(const void *addr, unsigned entries)
427 {
428 struct mmuext_op *op;
429 struct multicall_space mcs = xen_mc_entry(sizeof(*op));
430
431 trace_xen_cpu_set_ldt(addr, entries);
432
433 op = mcs.args;
434 op->cmd = MMUEXT_SET_LDT;
435 op->arg1.linear_addr = (unsigned long)addr;
436 op->arg2.nr_ents = entries;
437
438 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
439
440 xen_mc_issue(PARAVIRT_LAZY_CPU);
441 }
442
xen_load_gdt(const struct desc_ptr * dtr)443 static void xen_load_gdt(const struct desc_ptr *dtr)
444 {
445 unsigned long va = dtr->address;
446 unsigned int size = dtr->size + 1;
447 unsigned long pfn, mfn;
448 int level;
449 pte_t *ptep;
450 void *virt;
451
452 /* @size should be at most GDT_SIZE which is smaller than PAGE_SIZE. */
453 BUG_ON(size > PAGE_SIZE);
454 BUG_ON(va & ~PAGE_MASK);
455
456 /*
457 * The GDT is per-cpu and is in the percpu data area.
458 * That can be virtually mapped, so we need to do a
459 * page-walk to get the underlying MFN for the
460 * hypercall. The page can also be in the kernel's
461 * linear range, so we need to RO that mapping too.
462 */
463 ptep = lookup_address(va, &level);
464 BUG_ON(ptep == NULL);
465
466 pfn = pte_pfn(*ptep);
467 mfn = pfn_to_mfn(pfn);
468 virt = __va(PFN_PHYS(pfn));
469
470 make_lowmem_page_readonly((void *)va);
471 make_lowmem_page_readonly(virt);
472
473 if (HYPERVISOR_set_gdt(&mfn, size / sizeof(struct desc_struct)))
474 BUG();
475 }
476
477 /*
478 * load_gdt for early boot, when the gdt is only mapped once
479 */
xen_load_gdt_boot(const struct desc_ptr * dtr)480 static void __init xen_load_gdt_boot(const struct desc_ptr *dtr)
481 {
482 unsigned long va = dtr->address;
483 unsigned int size = dtr->size + 1;
484 unsigned long pfn, mfn;
485 pte_t pte;
486
487 /* @size should be at most GDT_SIZE which is smaller than PAGE_SIZE. */
488 BUG_ON(size > PAGE_SIZE);
489 BUG_ON(va & ~PAGE_MASK);
490
491 pfn = virt_to_pfn(va);
492 mfn = pfn_to_mfn(pfn);
493
494 pte = pfn_pte(pfn, PAGE_KERNEL_RO);
495
496 if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0))
497 BUG();
498
499 if (HYPERVISOR_set_gdt(&mfn, size / sizeof(struct desc_struct)))
500 BUG();
501 }
502
desc_equal(const struct desc_struct * d1,const struct desc_struct * d2)503 static inline bool desc_equal(const struct desc_struct *d1,
504 const struct desc_struct *d2)
505 {
506 return !memcmp(d1, d2, sizeof(*d1));
507 }
508
load_TLS_descriptor(struct thread_struct * t,unsigned int cpu,unsigned int i)509 static void load_TLS_descriptor(struct thread_struct *t,
510 unsigned int cpu, unsigned int i)
511 {
512 struct desc_struct *shadow = &per_cpu(shadow_tls_desc, cpu).desc[i];
513 struct desc_struct *gdt;
514 xmaddr_t maddr;
515 struct multicall_space mc;
516
517 if (desc_equal(shadow, &t->tls_array[i]))
518 return;
519
520 *shadow = t->tls_array[i];
521
522 gdt = get_cpu_gdt_rw(cpu);
523 maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
524 mc = __xen_mc_entry(0);
525
526 MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
527 }
528
xen_load_tls(struct thread_struct * t,unsigned int cpu)529 static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
530 {
531 /*
532 * XXX sleazy hack: If we're being called in a lazy-cpu zone
533 * and lazy gs handling is enabled, it means we're in a
534 * context switch, and %gs has just been saved. This means we
535 * can zero it out to prevent faults on exit from the
536 * hypervisor if the next process has no %gs. Either way, it
537 * has been saved, and the new value will get loaded properly.
538 * This will go away as soon as Xen has been modified to not
539 * save/restore %gs for normal hypercalls.
540 *
541 * On x86_64, this hack is not used for %gs, because gs points
542 * to KERNEL_GS_BASE (and uses it for PDA references), so we
543 * must not zero %gs on x86_64
544 *
545 * For x86_64, we need to zero %fs, otherwise we may get an
546 * exception between the new %fs descriptor being loaded and
547 * %fs being effectively cleared at __switch_to().
548 */
549 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
550 #ifdef CONFIG_X86_32
551 lazy_load_gs(0);
552 #else
553 loadsegment(fs, 0);
554 #endif
555 }
556
557 xen_mc_batch();
558
559 load_TLS_descriptor(t, cpu, 0);
560 load_TLS_descriptor(t, cpu, 1);
561 load_TLS_descriptor(t, cpu, 2);
562
563 xen_mc_issue(PARAVIRT_LAZY_CPU);
564 }
565
566 #ifdef CONFIG_X86_64
xen_load_gs_index(unsigned int idx)567 static void xen_load_gs_index(unsigned int idx)
568 {
569 if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
570 BUG();
571 }
572 #endif
573
xen_write_ldt_entry(struct desc_struct * dt,int entrynum,const void * ptr)574 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
575 const void *ptr)
576 {
577 xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
578 u64 entry = *(u64 *)ptr;
579
580 trace_xen_cpu_write_ldt_entry(dt, entrynum, entry);
581
582 preempt_disable();
583
584 xen_mc_flush();
585 if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
586 BUG();
587
588 preempt_enable();
589 }
590
591 #ifdef CONFIG_X86_64
592 struct trap_array_entry {
593 void (*orig)(void);
594 void (*xen)(void);
595 bool ist_okay;
596 };
597
598 static struct trap_array_entry trap_array[] = {
599 { debug, xen_xendebug, true },
600 { int3, xen_xenint3, true },
601 { double_fault, xen_double_fault, true },
602 #ifdef CONFIG_X86_MCE
603 { machine_check, xen_machine_check, true },
604 #endif
605 { nmi, xen_xennmi, true },
606 { overflow, xen_overflow, false },
607 #ifdef CONFIG_IA32_EMULATION
608 { entry_INT80_compat, xen_entry_INT80_compat, false },
609 #endif
610 { page_fault, xen_page_fault, false },
611 { divide_error, xen_divide_error, false },
612 { bounds, xen_bounds, false },
613 { invalid_op, xen_invalid_op, false },
614 { device_not_available, xen_device_not_available, false },
615 { coprocessor_segment_overrun, xen_coprocessor_segment_overrun, false },
616 { invalid_TSS, xen_invalid_TSS, false },
617 { segment_not_present, xen_segment_not_present, false },
618 { stack_segment, xen_stack_segment, false },
619 { general_protection, xen_general_protection, false },
620 { spurious_interrupt_bug, xen_spurious_interrupt_bug, false },
621 { coprocessor_error, xen_coprocessor_error, false },
622 { alignment_check, xen_alignment_check, false },
623 { simd_coprocessor_error, xen_simd_coprocessor_error, false },
624 };
625
get_trap_addr(void ** addr,unsigned int ist)626 static bool __ref get_trap_addr(void **addr, unsigned int ist)
627 {
628 unsigned int nr;
629 bool ist_okay = false;
630
631 /*
632 * Replace trap handler addresses by Xen specific ones.
633 * Check for known traps using IST and whitelist them.
634 * The debugger ones are the only ones we care about.
635 * Xen will handle faults like double_fault, * so we should never see
636 * them. Warn if there's an unexpected IST-using fault handler.
637 */
638 for (nr = 0; nr < ARRAY_SIZE(trap_array); nr++) {
639 struct trap_array_entry *entry = trap_array + nr;
640
641 if (*addr == entry->orig) {
642 *addr = entry->xen;
643 ist_okay = entry->ist_okay;
644 break;
645 }
646 }
647
648 if (nr == ARRAY_SIZE(trap_array) &&
649 *addr >= (void *)early_idt_handler_array[0] &&
650 *addr < (void *)early_idt_handler_array[NUM_EXCEPTION_VECTORS]) {
651 nr = (*addr - (void *)early_idt_handler_array[0]) /
652 EARLY_IDT_HANDLER_SIZE;
653 *addr = (void *)xen_early_idt_handler_array[nr];
654 }
655
656 if (WARN_ON(ist != 0 && !ist_okay))
657 return false;
658
659 return true;
660 }
661 #endif
662
cvt_gate_to_trap(int vector,const gate_desc * val,struct trap_info * info)663 static int cvt_gate_to_trap(int vector, const gate_desc *val,
664 struct trap_info *info)
665 {
666 unsigned long addr;
667
668 if (val->bits.type != GATE_TRAP && val->bits.type != GATE_INTERRUPT)
669 return 0;
670
671 info->vector = vector;
672
673 addr = gate_offset(val);
674 #ifdef CONFIG_X86_64
675 if (!get_trap_addr((void **)&addr, val->bits.ist))
676 return 0;
677 #endif /* CONFIG_X86_64 */
678 info->address = addr;
679
680 info->cs = gate_segment(val);
681 info->flags = val->bits.dpl;
682 /* interrupt gates clear IF */
683 if (val->bits.type == GATE_INTERRUPT)
684 info->flags |= 1 << 2;
685
686 return 1;
687 }
688
689 /* Locations of each CPU's IDT */
690 static DEFINE_PER_CPU(struct desc_ptr, idt_desc);
691
692 /* Set an IDT entry. If the entry is part of the current IDT, then
693 also update Xen. */
xen_write_idt_entry(gate_desc * dt,int entrynum,const gate_desc * g)694 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
695 {
696 unsigned long p = (unsigned long)&dt[entrynum];
697 unsigned long start, end;
698
699 trace_xen_cpu_write_idt_entry(dt, entrynum, g);
700
701 preempt_disable();
702
703 start = __this_cpu_read(idt_desc.address);
704 end = start + __this_cpu_read(idt_desc.size) + 1;
705
706 xen_mc_flush();
707
708 native_write_idt_entry(dt, entrynum, g);
709
710 if (p >= start && (p + 8) <= end) {
711 struct trap_info info[2];
712
713 info[1].address = 0;
714
715 if (cvt_gate_to_trap(entrynum, g, &info[0]))
716 if (HYPERVISOR_set_trap_table(info))
717 BUG();
718 }
719
720 preempt_enable();
721 }
722
xen_convert_trap_info(const struct desc_ptr * desc,struct trap_info * traps)723 static void xen_convert_trap_info(const struct desc_ptr *desc,
724 struct trap_info *traps)
725 {
726 unsigned in, out, count;
727
728 count = (desc->size+1) / sizeof(gate_desc);
729 BUG_ON(count > 256);
730
731 for (in = out = 0; in < count; in++) {
732 gate_desc *entry = (gate_desc *)(desc->address) + in;
733
734 if (cvt_gate_to_trap(in, entry, &traps[out]))
735 out++;
736 }
737 traps[out].address = 0;
738 }
739
xen_copy_trap_info(struct trap_info * traps)740 void xen_copy_trap_info(struct trap_info *traps)
741 {
742 const struct desc_ptr *desc = this_cpu_ptr(&idt_desc);
743
744 xen_convert_trap_info(desc, traps);
745 }
746
747 /* Load a new IDT into Xen. In principle this can be per-CPU, so we
748 hold a spinlock to protect the static traps[] array (static because
749 it avoids allocation, and saves stack space). */
xen_load_idt(const struct desc_ptr * desc)750 static void xen_load_idt(const struct desc_ptr *desc)
751 {
752 static DEFINE_SPINLOCK(lock);
753 static struct trap_info traps[257];
754
755 trace_xen_cpu_load_idt(desc);
756
757 spin_lock(&lock);
758
759 memcpy(this_cpu_ptr(&idt_desc), desc, sizeof(idt_desc));
760
761 xen_convert_trap_info(desc, traps);
762
763 xen_mc_flush();
764 if (HYPERVISOR_set_trap_table(traps))
765 BUG();
766
767 spin_unlock(&lock);
768 }
769
770 /* Write a GDT descriptor entry. Ignore LDT descriptors, since
771 they're handled differently. */
xen_write_gdt_entry(struct desc_struct * dt,int entry,const void * desc,int type)772 static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
773 const void *desc, int type)
774 {
775 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
776
777 preempt_disable();
778
779 switch (type) {
780 case DESC_LDT:
781 case DESC_TSS:
782 /* ignore */
783 break;
784
785 default: {
786 xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]);
787
788 xen_mc_flush();
789 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
790 BUG();
791 }
792
793 }
794
795 preempt_enable();
796 }
797
798 /*
799 * Version of write_gdt_entry for use at early boot-time needed to
800 * update an entry as simply as possible.
801 */
xen_write_gdt_entry_boot(struct desc_struct * dt,int entry,const void * desc,int type)802 static void __init xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
803 const void *desc, int type)
804 {
805 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
806
807 switch (type) {
808 case DESC_LDT:
809 case DESC_TSS:
810 /* ignore */
811 break;
812
813 default: {
814 xmaddr_t maddr = virt_to_machine(&dt[entry]);
815
816 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
817 dt[entry] = *(struct desc_struct *)desc;
818 }
819
820 }
821 }
822
xen_load_sp0(unsigned long sp0)823 static void xen_load_sp0(unsigned long sp0)
824 {
825 struct multicall_space mcs;
826
827 mcs = xen_mc_entry(0);
828 MULTI_stack_switch(mcs.mc, __KERNEL_DS, sp0);
829 xen_mc_issue(PARAVIRT_LAZY_CPU);
830 this_cpu_write(cpu_tss_rw.x86_tss.sp0, sp0);
831 }
832
xen_set_iopl_mask(unsigned mask)833 void xen_set_iopl_mask(unsigned mask)
834 {
835 struct physdev_set_iopl set_iopl;
836
837 /* Force the change at ring 0. */
838 set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
839 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
840 }
841
xen_io_delay(void)842 static void xen_io_delay(void)
843 {
844 }
845
846 static DEFINE_PER_CPU(unsigned long, xen_cr0_value);
847
xen_read_cr0(void)848 static unsigned long xen_read_cr0(void)
849 {
850 unsigned long cr0 = this_cpu_read(xen_cr0_value);
851
852 if (unlikely(cr0 == 0)) {
853 cr0 = native_read_cr0();
854 this_cpu_write(xen_cr0_value, cr0);
855 }
856
857 return cr0;
858 }
859
xen_write_cr0(unsigned long cr0)860 static void xen_write_cr0(unsigned long cr0)
861 {
862 struct multicall_space mcs;
863
864 this_cpu_write(xen_cr0_value, cr0);
865
866 /* Only pay attention to cr0.TS; everything else is
867 ignored. */
868 mcs = xen_mc_entry(0);
869
870 MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
871
872 xen_mc_issue(PARAVIRT_LAZY_CPU);
873 }
874
xen_write_cr4(unsigned long cr4)875 static void xen_write_cr4(unsigned long cr4)
876 {
877 cr4 &= ~(X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PCE);
878
879 native_write_cr4(cr4);
880 }
881 #ifdef CONFIG_X86_64
xen_read_cr8(void)882 static inline unsigned long xen_read_cr8(void)
883 {
884 return 0;
885 }
xen_write_cr8(unsigned long val)886 static inline void xen_write_cr8(unsigned long val)
887 {
888 BUG_ON(val);
889 }
890 #endif
891
xen_read_msr_safe(unsigned int msr,int * err)892 static u64 xen_read_msr_safe(unsigned int msr, int *err)
893 {
894 u64 val;
895
896 if (pmu_msr_read(msr, &val, err))
897 return val;
898
899 val = native_read_msr_safe(msr, err);
900 switch (msr) {
901 case MSR_IA32_APICBASE:
902 #ifdef CONFIG_X86_X2APIC
903 if (!(cpuid_ecx(1) & (1 << (X86_FEATURE_X2APIC & 31))))
904 #endif
905 val &= ~X2APIC_ENABLE;
906 break;
907 }
908 return val;
909 }
910
xen_write_msr_safe(unsigned int msr,unsigned low,unsigned high)911 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
912 {
913 int ret;
914
915 ret = 0;
916
917 switch (msr) {
918 #ifdef CONFIG_X86_64
919 unsigned which;
920 u64 base;
921
922 case MSR_FS_BASE: which = SEGBASE_FS; goto set;
923 case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set;
924 case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set;
925
926 set:
927 base = ((u64)high << 32) | low;
928 if (HYPERVISOR_set_segment_base(which, base) != 0)
929 ret = -EIO;
930 break;
931 #endif
932
933 case MSR_STAR:
934 case MSR_CSTAR:
935 case MSR_LSTAR:
936 case MSR_SYSCALL_MASK:
937 case MSR_IA32_SYSENTER_CS:
938 case MSR_IA32_SYSENTER_ESP:
939 case MSR_IA32_SYSENTER_EIP:
940 /* Fast syscall setup is all done in hypercalls, so
941 these are all ignored. Stub them out here to stop
942 Xen console noise. */
943 break;
944
945 default:
946 if (!pmu_msr_write(msr, low, high, &ret))
947 ret = native_write_msr_safe(msr, low, high);
948 }
949
950 return ret;
951 }
952
xen_read_msr(unsigned int msr)953 static u64 xen_read_msr(unsigned int msr)
954 {
955 /*
956 * This will silently swallow a #GP from RDMSR. It may be worth
957 * changing that.
958 */
959 int err;
960
961 return xen_read_msr_safe(msr, &err);
962 }
963
xen_write_msr(unsigned int msr,unsigned low,unsigned high)964 static void xen_write_msr(unsigned int msr, unsigned low, unsigned high)
965 {
966 /*
967 * This will silently swallow a #GP from WRMSR. It may be worth
968 * changing that.
969 */
970 xen_write_msr_safe(msr, low, high);
971 }
972
973 /* This is called once we have the cpu_possible_mask */
xen_setup_vcpu_info_placement(void)974 void __init xen_setup_vcpu_info_placement(void)
975 {
976 int cpu;
977
978 for_each_possible_cpu(cpu) {
979 /* Set up direct vCPU id mapping for PV guests. */
980 per_cpu(xen_vcpu_id, cpu) = cpu;
981
982 /*
983 * xen_vcpu_setup(cpu) can fail -- in which case it
984 * falls back to the shared_info version for cpus
985 * where xen_vcpu_nr(cpu) < MAX_VIRT_CPUS.
986 *
987 * xen_cpu_up_prepare_pv() handles the rest by failing
988 * them in hotplug.
989 */
990 (void) xen_vcpu_setup(cpu);
991 }
992
993 /*
994 * xen_vcpu_setup managed to place the vcpu_info within the
995 * percpu area for all cpus, so make use of it.
996 */
997 if (xen_have_vcpu_info_placement) {
998 pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
999 pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct);
1000 pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
1001 pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
1002 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
1003 }
1004 }
1005
1006 static const struct pv_info xen_info __initconst = {
1007 .shared_kernel_pmd = 0,
1008
1009 #ifdef CONFIG_X86_64
1010 .extra_user_64bit_cs = FLAT_USER_CS64,
1011 #endif
1012 .name = "Xen",
1013 };
1014
1015 static const struct pv_cpu_ops xen_cpu_ops __initconst = {
1016 .cpuid = xen_cpuid,
1017
1018 .set_debugreg = xen_set_debugreg,
1019 .get_debugreg = xen_get_debugreg,
1020
1021 .read_cr0 = xen_read_cr0,
1022 .write_cr0 = xen_write_cr0,
1023
1024 .write_cr4 = xen_write_cr4,
1025
1026 #ifdef CONFIG_X86_64
1027 .read_cr8 = xen_read_cr8,
1028 .write_cr8 = xen_write_cr8,
1029 #endif
1030
1031 .wbinvd = native_wbinvd,
1032
1033 .read_msr = xen_read_msr,
1034 .write_msr = xen_write_msr,
1035
1036 .read_msr_safe = xen_read_msr_safe,
1037 .write_msr_safe = xen_write_msr_safe,
1038
1039 .read_pmc = xen_read_pmc,
1040
1041 .iret = xen_iret,
1042 #ifdef CONFIG_X86_64
1043 .usergs_sysret64 = xen_sysret64,
1044 #endif
1045
1046 .load_tr_desc = paravirt_nop,
1047 .set_ldt = xen_set_ldt,
1048 .load_gdt = xen_load_gdt,
1049 .load_idt = xen_load_idt,
1050 .load_tls = xen_load_tls,
1051 #ifdef CONFIG_X86_64
1052 .load_gs_index = xen_load_gs_index,
1053 #endif
1054
1055 .alloc_ldt = xen_alloc_ldt,
1056 .free_ldt = xen_free_ldt,
1057
1058 .store_tr = xen_store_tr,
1059
1060 .write_ldt_entry = xen_write_ldt_entry,
1061 .write_gdt_entry = xen_write_gdt_entry,
1062 .write_idt_entry = xen_write_idt_entry,
1063 .load_sp0 = xen_load_sp0,
1064
1065 .set_iopl_mask = xen_set_iopl_mask,
1066 .io_delay = xen_io_delay,
1067
1068 /* Xen takes care of %gs when switching to usermode for us */
1069 .swapgs = paravirt_nop,
1070
1071 .start_context_switch = paravirt_start_context_switch,
1072 .end_context_switch = xen_end_context_switch,
1073 };
1074
xen_restart(char * msg)1075 static void xen_restart(char *msg)
1076 {
1077 xen_reboot(SHUTDOWN_reboot);
1078 }
1079
xen_machine_halt(void)1080 static void xen_machine_halt(void)
1081 {
1082 xen_reboot(SHUTDOWN_poweroff);
1083 }
1084
xen_machine_power_off(void)1085 static void xen_machine_power_off(void)
1086 {
1087 if (pm_power_off)
1088 pm_power_off();
1089 xen_reboot(SHUTDOWN_poweroff);
1090 }
1091
xen_crash_shutdown(struct pt_regs * regs)1092 static void xen_crash_shutdown(struct pt_regs *regs)
1093 {
1094 xen_reboot(SHUTDOWN_crash);
1095 }
1096
1097 static const struct machine_ops xen_machine_ops __initconst = {
1098 .restart = xen_restart,
1099 .halt = xen_machine_halt,
1100 .power_off = xen_machine_power_off,
1101 .shutdown = xen_machine_halt,
1102 .crash_shutdown = xen_crash_shutdown,
1103 .emergency_restart = xen_emergency_restart,
1104 };
1105
xen_get_nmi_reason(void)1106 static unsigned char xen_get_nmi_reason(void)
1107 {
1108 unsigned char reason = 0;
1109
1110 /* Construct a value which looks like it came from port 0x61. */
1111 if (test_bit(_XEN_NMIREASON_io_error,
1112 &HYPERVISOR_shared_info->arch.nmi_reason))
1113 reason |= NMI_REASON_IOCHK;
1114 if (test_bit(_XEN_NMIREASON_pci_serr,
1115 &HYPERVISOR_shared_info->arch.nmi_reason))
1116 reason |= NMI_REASON_SERR;
1117
1118 return reason;
1119 }
1120
xen_boot_params_init_edd(void)1121 static void __init xen_boot_params_init_edd(void)
1122 {
1123 #if IS_ENABLED(CONFIG_EDD)
1124 struct xen_platform_op op;
1125 struct edd_info *edd_info;
1126 u32 *mbr_signature;
1127 unsigned nr;
1128 int ret;
1129
1130 edd_info = boot_params.eddbuf;
1131 mbr_signature = boot_params.edd_mbr_sig_buffer;
1132
1133 op.cmd = XENPF_firmware_info;
1134
1135 op.u.firmware_info.type = XEN_FW_DISK_INFO;
1136 for (nr = 0; nr < EDDMAXNR; nr++) {
1137 struct edd_info *info = edd_info + nr;
1138
1139 op.u.firmware_info.index = nr;
1140 info->params.length = sizeof(info->params);
1141 set_xen_guest_handle(op.u.firmware_info.u.disk_info.edd_params,
1142 &info->params);
1143 ret = HYPERVISOR_platform_op(&op);
1144 if (ret)
1145 break;
1146
1147 #define C(x) info->x = op.u.firmware_info.u.disk_info.x
1148 C(device);
1149 C(version);
1150 C(interface_support);
1151 C(legacy_max_cylinder);
1152 C(legacy_max_head);
1153 C(legacy_sectors_per_track);
1154 #undef C
1155 }
1156 boot_params.eddbuf_entries = nr;
1157
1158 op.u.firmware_info.type = XEN_FW_DISK_MBR_SIGNATURE;
1159 for (nr = 0; nr < EDD_MBR_SIG_MAX; nr++) {
1160 op.u.firmware_info.index = nr;
1161 ret = HYPERVISOR_platform_op(&op);
1162 if (ret)
1163 break;
1164 mbr_signature[nr] = op.u.firmware_info.u.disk_mbr_signature.mbr_signature;
1165 }
1166 boot_params.edd_mbr_sig_buf_entries = nr;
1167 #endif
1168 }
1169
1170 /*
1171 * Set up the GDT and segment registers for -fstack-protector. Until
1172 * we do this, we have to be careful not to call any stack-protected
1173 * function, which is most of the kernel.
1174 */
xen_setup_gdt(int cpu)1175 static void __init xen_setup_gdt(int cpu)
1176 {
1177 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
1178 pv_cpu_ops.load_gdt = xen_load_gdt_boot;
1179
1180 setup_stack_canary_segment(cpu);
1181 switch_to_new_gdt(cpu);
1182
1183 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry;
1184 pv_cpu_ops.load_gdt = xen_load_gdt;
1185 }
1186
xen_dom0_set_legacy_features(void)1187 static void __init xen_dom0_set_legacy_features(void)
1188 {
1189 x86_platform.legacy.rtc = 1;
1190 }
1191
1192 /* First C function to be called on Xen boot */
xen_start_kernel(void)1193 asmlinkage __visible void __init xen_start_kernel(void)
1194 {
1195 struct physdev_set_iopl set_iopl;
1196 unsigned long initrd_start = 0;
1197 int rc;
1198
1199 if (!xen_start_info)
1200 return;
1201
1202 xen_domain_type = XEN_PV_DOMAIN;
1203 xen_start_flags = xen_start_info->flags;
1204
1205 xen_setup_features();
1206
1207 /* Install Xen paravirt ops */
1208 pv_info = xen_info;
1209 pv_init_ops.patch = paravirt_patch_default;
1210 pv_cpu_ops = xen_cpu_ops;
1211 xen_init_irq_ops();
1212
1213 /*
1214 * Setup xen_vcpu early because it is needed for
1215 * local_irq_disable(), irqs_disabled(), e.g. in printk().
1216 *
1217 * Don't do the full vcpu_info placement stuff until we have
1218 * the cpu_possible_mask and a non-dummy shared_info.
1219 */
1220 xen_vcpu_info_reset(0);
1221
1222 x86_platform.get_nmi_reason = xen_get_nmi_reason;
1223
1224 x86_init.resources.memory_setup = xen_memory_setup;
1225 x86_init.irqs.intr_mode_init = x86_init_noop;
1226 x86_init.oem.arch_setup = xen_arch_setup;
1227 x86_init.oem.banner = xen_banner;
1228 x86_init.hyper.init_platform = xen_pv_init_platform;
1229 x86_init.hyper.guest_late_init = xen_pv_guest_late_init;
1230
1231 /*
1232 * Set up some pagetable state before starting to set any ptes.
1233 */
1234
1235 xen_setup_machphys_mapping();
1236 xen_init_mmu_ops();
1237
1238 /* Prevent unwanted bits from being set in PTEs. */
1239 __supported_pte_mask &= ~_PAGE_GLOBAL;
1240 __default_kernel_pte_mask &= ~_PAGE_GLOBAL;
1241
1242 /*
1243 * Prevent page tables from being allocated in highmem, even
1244 * if CONFIG_HIGHPTE is enabled.
1245 */
1246 __userpte_alloc_gfp &= ~__GFP_HIGHMEM;
1247
1248 /* Get mfn list */
1249 xen_build_dynamic_phys_to_machine();
1250
1251 /*
1252 * Set up kernel GDT and segment registers, mainly so that
1253 * -fstack-protector code can be executed.
1254 */
1255 xen_setup_gdt(0);
1256
1257 /* Work out if we support NX */
1258 get_cpu_cap(&boot_cpu_data);
1259 x86_configure_nx();
1260
1261 /* Determine virtual and physical address sizes */
1262 get_cpu_address_sizes(&boot_cpu_data);
1263
1264 /* Let's presume PV guests always boot on vCPU with id 0. */
1265 per_cpu(xen_vcpu_id, 0) = 0;
1266
1267 idt_setup_early_handler();
1268
1269 xen_init_capabilities();
1270
1271 #ifdef CONFIG_X86_LOCAL_APIC
1272 /*
1273 * set up the basic apic ops.
1274 */
1275 xen_init_apic();
1276 #endif
1277
1278 if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
1279 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
1280 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
1281 }
1282
1283 machine_ops = xen_machine_ops;
1284
1285 /*
1286 * The only reliable way to retain the initial address of the
1287 * percpu gdt_page is to remember it here, so we can go and
1288 * mark it RW later, when the initial percpu area is freed.
1289 */
1290 xen_initial_gdt = &per_cpu(gdt_page, 0);
1291
1292 xen_smp_init();
1293
1294 #ifdef CONFIG_ACPI_NUMA
1295 /*
1296 * The pages we from Xen are not related to machine pages, so
1297 * any NUMA information the kernel tries to get from ACPI will
1298 * be meaningless. Prevent it from trying.
1299 */
1300 acpi_numa = -1;
1301 #endif
1302 WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_pv, xen_cpu_dead_pv));
1303
1304 local_irq_disable();
1305 early_boot_irqs_disabled = true;
1306
1307 xen_raw_console_write("mapping kernel into physical memory\n");
1308 xen_setup_kernel_pagetable((pgd_t *)xen_start_info->pt_base,
1309 xen_start_info->nr_pages);
1310 xen_reserve_special_pages();
1311
1312 /* keep using Xen gdt for now; no urgent need to change it */
1313
1314 #ifdef CONFIG_X86_32
1315 pv_info.kernel_rpl = 1;
1316 if (xen_feature(XENFEAT_supervisor_mode_kernel))
1317 pv_info.kernel_rpl = 0;
1318 #else
1319 pv_info.kernel_rpl = 0;
1320 #endif
1321 /* set the limit of our address space */
1322 xen_reserve_top();
1323
1324 /*
1325 * We used to do this in xen_arch_setup, but that is too late
1326 * on AMD were early_cpu_init (run before ->arch_setup()) calls
1327 * early_amd_init which pokes 0xcf8 port.
1328 */
1329 set_iopl.iopl = 1;
1330 rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
1331 if (rc != 0)
1332 xen_raw_printk("physdev_op failed %d\n", rc);
1333
1334 #ifdef CONFIG_X86_32
1335 /* set up basic CPUID stuff */
1336 cpu_detect(&new_cpu_data);
1337 set_cpu_cap(&new_cpu_data, X86_FEATURE_FPU);
1338 new_cpu_data.x86_capability[CPUID_1_EDX] = cpuid_edx(1);
1339 #endif
1340
1341 if (xen_start_info->mod_start) {
1342 if (xen_start_info->flags & SIF_MOD_START_PFN)
1343 initrd_start = PFN_PHYS(xen_start_info->mod_start);
1344 else
1345 initrd_start = __pa(xen_start_info->mod_start);
1346 }
1347
1348 /* Poke various useful things into boot_params */
1349 boot_params.hdr.type_of_loader = (9 << 4) | 0;
1350 boot_params.hdr.ramdisk_image = initrd_start;
1351 boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
1352 boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
1353 boot_params.hdr.hardware_subarch = X86_SUBARCH_XEN;
1354
1355 if (!xen_initial_domain()) {
1356 add_preferred_console("xenboot", 0, NULL);
1357 if (pci_xen)
1358 x86_init.pci.arch_init = pci_xen_init;
1359 } else {
1360 const struct dom0_vga_console_info *info =
1361 (void *)((char *)xen_start_info +
1362 xen_start_info->console.dom0.info_off);
1363 struct xen_platform_op op = {
1364 .cmd = XENPF_firmware_info,
1365 .interface_version = XENPF_INTERFACE_VERSION,
1366 .u.firmware_info.type = XEN_FW_KBD_SHIFT_FLAGS,
1367 };
1368
1369 x86_platform.set_legacy_features =
1370 xen_dom0_set_legacy_features;
1371 xen_init_vga(info, xen_start_info->console.dom0.info_size);
1372 xen_start_info->console.domU.mfn = 0;
1373 xen_start_info->console.domU.evtchn = 0;
1374
1375 if (HYPERVISOR_platform_op(&op) == 0)
1376 boot_params.kbd_status = op.u.firmware_info.u.kbd_shift_flags;
1377
1378 /* Make sure ACS will be enabled */
1379 pci_request_acs();
1380
1381 xen_acpi_sleep_register();
1382
1383 /* Avoid searching for BIOS MP tables */
1384 x86_init.mpparse.find_smp_config = x86_init_noop;
1385 x86_init.mpparse.get_smp_config = x86_init_uint_noop;
1386
1387 xen_boot_params_init_edd();
1388 }
1389
1390 if (!boot_params.screen_info.orig_video_isVGA)
1391 add_preferred_console("tty", 0, NULL);
1392 add_preferred_console("hvc", 0, NULL);
1393 if (boot_params.screen_info.orig_video_isVGA)
1394 add_preferred_console("tty", 0, NULL);
1395
1396 #ifdef CONFIG_PCI
1397 /* PCI BIOS service won't work from a PV guest. */
1398 pci_probe &= ~PCI_PROBE_BIOS;
1399 #endif
1400 xen_raw_console_write("about to get started...\n");
1401
1402 /* We need this for printk timestamps */
1403 xen_setup_runstate_info(0);
1404
1405 xen_efi_init();
1406
1407 /* Start the world */
1408 #ifdef CONFIG_X86_32
1409 i386_start_kernel();
1410 #else
1411 cr4_init_shadow(); /* 32b kernel does this in i386_start_kernel() */
1412 x86_64_start_reservations((char *)__pa_symbol(&boot_params));
1413 #endif
1414 }
1415
xen_cpu_up_prepare_pv(unsigned int cpu)1416 static int xen_cpu_up_prepare_pv(unsigned int cpu)
1417 {
1418 int rc;
1419
1420 if (per_cpu(xen_vcpu, cpu) == NULL)
1421 return -ENODEV;
1422
1423 xen_setup_timer(cpu);
1424
1425 rc = xen_smp_intr_init(cpu);
1426 if (rc) {
1427 WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n",
1428 cpu, rc);
1429 return rc;
1430 }
1431
1432 rc = xen_smp_intr_init_pv(cpu);
1433 if (rc) {
1434 WARN(1, "xen_smp_intr_init_pv() for CPU %d failed: %d\n",
1435 cpu, rc);
1436 return rc;
1437 }
1438
1439 return 0;
1440 }
1441
xen_cpu_dead_pv(unsigned int cpu)1442 static int xen_cpu_dead_pv(unsigned int cpu)
1443 {
1444 xen_smp_intr_free(cpu);
1445 xen_smp_intr_free_pv(cpu);
1446
1447 xen_teardown_timer(cpu);
1448
1449 return 0;
1450 }
1451
xen_platform_pv(void)1452 static uint32_t __init xen_platform_pv(void)
1453 {
1454 if (xen_pv_domain())
1455 return xen_cpuid_base();
1456
1457 return 0;
1458 }
1459
1460 const __initconst struct hypervisor_x86 x86_hyper_xen_pv = {
1461 .name = "Xen PV",
1462 .detect = xen_platform_pv,
1463 .type = X86_HYPER_XEN_PV,
1464 .runtime.pin_vcpu = xen_pin_vcpu,
1465 };
1466
