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/export.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 #include <linux/frame.h>
36
37 #include <linux/kexec.h>
38
39 #include <xen/xen.h>
40 #include <xen/events.h>
41 #include <xen/interface/xen.h>
42 #include <xen/interface/version.h>
43 #include <xen/interface/physdev.h>
44 #include <xen/interface/vcpu.h>
45 #include <xen/interface/memory.h>
46 #include <xen/interface/nmi.h>
47 #include <xen/interface/xen-mca.h>
48 #include <xen/features.h>
49 #include <xen/page.h>
50 #include <xen/hvm.h>
51 #include <xen/hvc-console.h>
52 #include <xen/acpi.h>
53
54 #include <asm/paravirt.h>
55 #include <asm/apic.h>
56 #include <asm/page.h>
57 #include <asm/xen/pci.h>
58 #include <asm/xen/hypercall.h>
59 #include <asm/xen/hypervisor.h>
60 #include <asm/xen/cpuid.h>
61 #include <asm/fixmap.h>
62 #include <asm/processor.h>
63 #include <asm/proto.h>
64 #include <asm/msr-index.h>
65 #include <asm/traps.h>
66 #include <asm/setup.h>
67 #include <asm/desc.h>
68 #include <asm/pgalloc.h>
69 #include <asm/pgtable.h>
70 #include <asm/tlbflush.h>
71 #include <asm/reboot.h>
72 #include <asm/stackprotector.h>
73 #include <asm/hypervisor.h>
74 #include <asm/mach_traps.h>
75 #include <asm/mwait.h>
76 #include <asm/pci_x86.h>
77 #include <asm/cpu.h>
78
79 #ifdef CONFIG_ACPI
80 #include <linux/acpi.h>
81 #include <asm/acpi.h>
82 #include <acpi/pdc_intel.h>
83 #include <acpi/processor.h>
84 #include <xen/interface/platform.h>
85 #endif
86
87 #include "xen-ops.h"
88 #include "mmu.h"
89 #include "smp.h"
90 #include "multicalls.h"
91 #include "pmu.h"
92
93 EXPORT_SYMBOL_GPL(hypercall_page);
94
95 /*
96 * Pointer to the xen_vcpu_info structure or
97 * &HYPERVISOR_shared_info->vcpu_info[cpu]. See xen_hvm_init_shared_info
98 * and xen_vcpu_setup for details. By default it points to share_info->vcpu_info
99 * but if the hypervisor supports VCPUOP_register_vcpu_info then it can point
100 * to xen_vcpu_info. The pointer is used in __xen_evtchn_do_upcall to
101 * acknowledge pending events.
102 * Also more subtly it is used by the patched version of irq enable/disable
103 * e.g. xen_irq_enable_direct and xen_iret in PV mode.
104 *
105 * The desire to be able to do those mask/unmask operations as a single
106 * instruction by using the per-cpu offset held in %gs is the real reason
107 * vcpu info is in a per-cpu pointer and the original reason for this
108 * hypercall.
109 *
110 */
111 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
112
113 /*
114 * Per CPU pages used if hypervisor supports VCPUOP_register_vcpu_info
115 * hypercall. This can be used both in PV and PVHVM mode. The structure
116 * overrides the default per_cpu(xen_vcpu, cpu) value.
117 */
118 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
119
120 /* Linux <-> Xen vCPU id mapping */
121 DEFINE_PER_CPU(uint32_t, xen_vcpu_id);
122 EXPORT_PER_CPU_SYMBOL(xen_vcpu_id);
123
124 enum xen_domain_type xen_domain_type = XEN_NATIVE;
125 EXPORT_SYMBOL_GPL(xen_domain_type);
126
127 unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START;
128 EXPORT_SYMBOL(machine_to_phys_mapping);
129 unsigned long machine_to_phys_nr;
130 EXPORT_SYMBOL(machine_to_phys_nr);
131
132 struct start_info *xen_start_info;
133 EXPORT_SYMBOL_GPL(xen_start_info);
134
135 struct shared_info xen_dummy_shared_info;
136
137 void *xen_initial_gdt;
138
139 RESERVE_BRK(shared_info_page_brk, PAGE_SIZE);
140 __read_mostly int xen_have_vector_callback;
141 EXPORT_SYMBOL_GPL(xen_have_vector_callback);
142
143 static int xen_cpu_up_prepare(unsigned int cpu);
144 static int xen_cpu_up_online(unsigned int cpu);
145 static int xen_cpu_dead(unsigned int cpu);
146
147 /*
148 * Point at some empty memory to start with. We map the real shared_info
149 * page as soon as fixmap is up and running.
150 */
151 struct shared_info *HYPERVISOR_shared_info = &xen_dummy_shared_info;
152
153 /*
154 * Flag to determine whether vcpu info placement is available on all
155 * VCPUs. We assume it is to start with, and then set it to zero on
156 * the first failure. This is because it can succeed on some VCPUs
157 * and not others, since it can involve hypervisor memory allocation,
158 * or because the guest failed to guarantee all the appropriate
159 * constraints on all VCPUs (ie buffer can't cross a page boundary).
160 *
161 * Note that any particular CPU may be using a placed vcpu structure,
162 * but we can only optimise if the all are.
163 *
164 * 0: not available, 1: available
165 */
166 static int have_vcpu_info_placement = 1;
167
168 struct tls_descs {
169 struct desc_struct desc[3];
170 };
171
172 /*
173 * Updating the 3 TLS descriptors in the GDT on every task switch is
174 * surprisingly expensive so we avoid updating them if they haven't
175 * changed. Since Xen writes different descriptors than the one
176 * passed in the update_descriptor hypercall we keep shadow copies to
177 * compare against.
178 */
179 static DEFINE_PER_CPU(struct tls_descs, shadow_tls_desc);
180
clamp_max_cpus(void)181 static void clamp_max_cpus(void)
182 {
183 #ifdef CONFIG_SMP
184 if (setup_max_cpus > MAX_VIRT_CPUS)
185 setup_max_cpus = MAX_VIRT_CPUS;
186 #endif
187 }
188
xen_vcpu_setup(int cpu)189 void xen_vcpu_setup(int cpu)
190 {
191 struct vcpu_register_vcpu_info info;
192 int err;
193 struct vcpu_info *vcpup;
194
195 BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
196
197 /*
198 * This path is called twice on PVHVM - first during bootup via
199 * smp_init -> xen_hvm_cpu_notify, and then if the VCPU is being
200 * hotplugged: cpu_up -> xen_hvm_cpu_notify.
201 * As we can only do the VCPUOP_register_vcpu_info once lets
202 * not over-write its result.
203 *
204 * For PV it is called during restore (xen_vcpu_restore) and bootup
205 * (xen_setup_vcpu_info_placement). The hotplug mechanism does not
206 * use this function.
207 */
208 if (xen_hvm_domain()) {
209 if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu))
210 return;
211 }
212 if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS)
213 per_cpu(xen_vcpu, cpu) =
214 &HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
215
216 if (!have_vcpu_info_placement) {
217 if (cpu >= MAX_VIRT_CPUS)
218 clamp_max_cpus();
219 return;
220 }
221
222 vcpup = &per_cpu(xen_vcpu_info, cpu);
223 info.mfn = arbitrary_virt_to_mfn(vcpup);
224 info.offset = offset_in_page(vcpup);
225
226 /* Check to see if the hypervisor will put the vcpu_info
227 structure where we want it, which allows direct access via
228 a percpu-variable.
229 N.B. This hypercall can _only_ be called once per CPU. Subsequent
230 calls will error out with -EINVAL. This is due to the fact that
231 hypervisor has no unregister variant and this hypercall does not
232 allow to over-write info.mfn and info.offset.
233 */
234 err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
235 &info);
236
237 if (err) {
238 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
239 have_vcpu_info_placement = 0;
240 clamp_max_cpus();
241 } else {
242 /* This cpu is using the registered vcpu info, even if
243 later ones fail to. */
244 per_cpu(xen_vcpu, cpu) = vcpup;
245 }
246 }
247
248 /*
249 * On restore, set the vcpu placement up again.
250 * If it fails, then we're in a bad state, since
251 * we can't back out from using it...
252 */
xen_vcpu_restore(void)253 void xen_vcpu_restore(void)
254 {
255 int cpu;
256
257 for_each_possible_cpu(cpu) {
258 bool other_cpu = (cpu != smp_processor_id());
259 bool is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up, xen_vcpu_nr(cpu),
260 NULL);
261
262 if (other_cpu && is_up &&
263 HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(cpu), NULL))
264 BUG();
265
266 xen_setup_runstate_info(cpu);
267
268 if (have_vcpu_info_placement)
269 xen_vcpu_setup(cpu);
270
271 if (other_cpu && is_up &&
272 HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL))
273 BUG();
274 }
275 }
276
xen_banner(void)277 static void __init xen_banner(void)
278 {
279 unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
280 struct xen_extraversion extra;
281 HYPERVISOR_xen_version(XENVER_extraversion, &extra);
282
283 pr_info("Booting paravirtualized kernel %son %s\n",
284 xen_feature(XENFEAT_auto_translated_physmap) ?
285 "with PVH extensions " : "", pv_info.name);
286 printk(KERN_INFO "Xen version: %d.%d%s%s\n",
287 version >> 16, version & 0xffff, extra.extraversion,
288 xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
289 }
290 /* Check if running on Xen version (major, minor) or later */
291 bool
xen_running_on_version_or_later(unsigned int major,unsigned int minor)292 xen_running_on_version_or_later(unsigned int major, unsigned int minor)
293 {
294 unsigned int version;
295
296 if (!xen_domain())
297 return false;
298
299 version = HYPERVISOR_xen_version(XENVER_version, NULL);
300 if ((((version >> 16) == major) && ((version & 0xffff) >= minor)) ||
301 ((version >> 16) > major))
302 return true;
303 return false;
304 }
305
306 #define CPUID_THERM_POWER_LEAF 6
307 #define APERFMPERF_PRESENT 0
308
309 static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
310 static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
311
312 static __read_mostly unsigned int cpuid_leaf1_ecx_set_mask;
313 static __read_mostly unsigned int cpuid_leaf5_ecx_val;
314 static __read_mostly unsigned int cpuid_leaf5_edx_val;
315
xen_cpuid(unsigned int * ax,unsigned int * bx,unsigned int * cx,unsigned int * dx)316 static void xen_cpuid(unsigned int *ax, unsigned int *bx,
317 unsigned int *cx, unsigned int *dx)
318 {
319 unsigned maskebx = ~0;
320 unsigned maskecx = ~0;
321 unsigned maskedx = ~0;
322 unsigned setecx = 0;
323 /*
324 * Mask out inconvenient features, to try and disable as many
325 * unsupported kernel subsystems as possible.
326 */
327 switch (*ax) {
328 case 1:
329 maskecx = cpuid_leaf1_ecx_mask;
330 setecx = cpuid_leaf1_ecx_set_mask;
331 maskedx = cpuid_leaf1_edx_mask;
332 break;
333
334 case CPUID_MWAIT_LEAF:
335 /* Synthesize the values.. */
336 *ax = 0;
337 *bx = 0;
338 *cx = cpuid_leaf5_ecx_val;
339 *dx = cpuid_leaf5_edx_val;
340 return;
341
342 case CPUID_THERM_POWER_LEAF:
343 /* Disabling APERFMPERF for kernel usage */
344 maskecx = ~(1 << APERFMPERF_PRESENT);
345 break;
346
347 case 0xb:
348 /* Suppress extended topology stuff */
349 maskebx = 0;
350 break;
351 }
352
353 asm(XEN_EMULATE_PREFIX "cpuid"
354 : "=a" (*ax),
355 "=b" (*bx),
356 "=c" (*cx),
357 "=d" (*dx)
358 : "0" (*ax), "2" (*cx));
359
360 *bx &= maskebx;
361 *cx &= maskecx;
362 *cx |= setecx;
363 *dx &= maskedx;
364 }
365 STACK_FRAME_NON_STANDARD(xen_cpuid); /* XEN_EMULATE_PREFIX */
366
xen_check_mwait(void)367 static bool __init xen_check_mwait(void)
368 {
369 #ifdef CONFIG_ACPI
370 struct xen_platform_op op = {
371 .cmd = XENPF_set_processor_pminfo,
372 .u.set_pminfo.id = -1,
373 .u.set_pminfo.type = XEN_PM_PDC,
374 };
375 uint32_t buf[3];
376 unsigned int ax, bx, cx, dx;
377 unsigned int mwait_mask;
378
379 /* We need to determine whether it is OK to expose the MWAIT
380 * capability to the kernel to harvest deeper than C3 states from ACPI
381 * _CST using the processor_harvest_xen.c module. For this to work, we
382 * need to gather the MWAIT_LEAF values (which the cstate.c code
383 * checks against). The hypervisor won't expose the MWAIT flag because
384 * it would break backwards compatibility; so we will find out directly
385 * from the hardware and hypercall.
386 */
387 if (!xen_initial_domain())
388 return false;
389
390 /*
391 * When running under platform earlier than Xen4.2, do not expose
392 * mwait, to avoid the risk of loading native acpi pad driver
393 */
394 if (!xen_running_on_version_or_later(4, 2))
395 return false;
396
397 ax = 1;
398 cx = 0;
399
400 native_cpuid(&ax, &bx, &cx, &dx);
401
402 mwait_mask = (1 << (X86_FEATURE_EST % 32)) |
403 (1 << (X86_FEATURE_MWAIT % 32));
404
405 if ((cx & mwait_mask) != mwait_mask)
406 return false;
407
408 /* We need to emulate the MWAIT_LEAF and for that we need both
409 * ecx and edx. The hypercall provides only partial information.
410 */
411
412 ax = CPUID_MWAIT_LEAF;
413 bx = 0;
414 cx = 0;
415 dx = 0;
416
417 native_cpuid(&ax, &bx, &cx, &dx);
418
419 /* Ask the Hypervisor whether to clear ACPI_PDC_C_C2C3_FFH. If so,
420 * don't expose MWAIT_LEAF and let ACPI pick the IOPORT version of C3.
421 */
422 buf[0] = ACPI_PDC_REVISION_ID;
423 buf[1] = 1;
424 buf[2] = (ACPI_PDC_C_CAPABILITY_SMP | ACPI_PDC_EST_CAPABILITY_SWSMP);
425
426 set_xen_guest_handle(op.u.set_pminfo.pdc, buf);
427
428 if ((HYPERVISOR_platform_op(&op) == 0) &&
429 (buf[2] & (ACPI_PDC_C_C1_FFH | ACPI_PDC_C_C2C3_FFH))) {
430 cpuid_leaf5_ecx_val = cx;
431 cpuid_leaf5_edx_val = dx;
432 }
433 return true;
434 #else
435 return false;
436 #endif
437 }
xen_init_cpuid_mask(void)438 static void __init xen_init_cpuid_mask(void)
439 {
440 unsigned int ax, bx, cx, dx;
441 unsigned int xsave_mask;
442
443 cpuid_leaf1_edx_mask =
444 ~((1 << X86_FEATURE_MTRR) | /* disable MTRR */
445 (1 << X86_FEATURE_ACC)); /* thermal monitoring */
446
447 /*
448 * Xen PV would need some work to support PCID: CR3 handling as well
449 * as xen_flush_tlb_others() would need updating.
450 */
451 cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_PCID % 32)); /* disable PCID */
452
453 if (!xen_initial_domain())
454 cpuid_leaf1_edx_mask &=
455 ~((1 << X86_FEATURE_ACPI)); /* disable ACPI */
456
457 cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_X2APIC % 32));
458
459 ax = 1;
460 cx = 0;
461 cpuid(1, &ax, &bx, &cx, &dx);
462
463 xsave_mask =
464 (1 << (X86_FEATURE_XSAVE % 32)) |
465 (1 << (X86_FEATURE_OSXSAVE % 32));
466
467 /* Xen will set CR4.OSXSAVE if supported and not disabled by force */
468 if ((cx & xsave_mask) != xsave_mask)
469 cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */
470 if (xen_check_mwait())
471 cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32));
472 }
473
xen_set_debugreg(int reg,unsigned long val)474 static void xen_set_debugreg(int reg, unsigned long val)
475 {
476 HYPERVISOR_set_debugreg(reg, val);
477 }
478
xen_get_debugreg(int reg)479 static unsigned long xen_get_debugreg(int reg)
480 {
481 return HYPERVISOR_get_debugreg(reg);
482 }
483
xen_end_context_switch(struct task_struct * next)484 static void xen_end_context_switch(struct task_struct *next)
485 {
486 xen_mc_flush();
487 paravirt_end_context_switch(next);
488 }
489
xen_store_tr(void)490 static unsigned long xen_store_tr(void)
491 {
492 return 0;
493 }
494
495 /*
496 * Set the page permissions for a particular virtual address. If the
497 * address is a vmalloc mapping (or other non-linear mapping), then
498 * find the linear mapping of the page and also set its protections to
499 * match.
500 */
set_aliased_prot(void * v,pgprot_t prot)501 static void set_aliased_prot(void *v, pgprot_t prot)
502 {
503 int level;
504 pte_t *ptep;
505 pte_t pte;
506 unsigned long pfn;
507 struct page *page;
508 unsigned char dummy;
509
510 ptep = lookup_address((unsigned long)v, &level);
511 BUG_ON(ptep == NULL);
512
513 pfn = pte_pfn(*ptep);
514 page = pfn_to_page(pfn);
515
516 pte = pfn_pte(pfn, prot);
517
518 /*
519 * Careful: update_va_mapping() will fail if the virtual address
520 * we're poking isn't populated in the page tables. We don't
521 * need to worry about the direct map (that's always in the page
522 * tables), but we need to be careful about vmap space. In
523 * particular, the top level page table can lazily propagate
524 * entries between processes, so if we've switched mms since we
525 * vmapped the target in the first place, we might not have the
526 * top-level page table entry populated.
527 *
528 * We disable preemption because we want the same mm active when
529 * we probe the target and when we issue the hypercall. We'll
530 * have the same nominal mm, but if we're a kernel thread, lazy
531 * mm dropping could change our pgd.
532 *
533 * Out of an abundance of caution, this uses __get_user() to fault
534 * in the target address just in case there's some obscure case
535 * in which the target address isn't readable.
536 */
537
538 preempt_disable();
539
540 probe_kernel_read(&dummy, v, 1);
541
542 if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
543 BUG();
544
545 if (!PageHighMem(page)) {
546 void *av = __va(PFN_PHYS(pfn));
547
548 if (av != v)
549 if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
550 BUG();
551 } else
552 kmap_flush_unused();
553
554 preempt_enable();
555 }
556
xen_alloc_ldt(struct desc_struct * ldt,unsigned entries)557 static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
558 {
559 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
560 int i;
561
562 /*
563 * We need to mark the all aliases of the LDT pages RO. We
564 * don't need to call vm_flush_aliases(), though, since that's
565 * only responsible for flushing aliases out the TLBs, not the
566 * page tables, and Xen will flush the TLB for us if needed.
567 *
568 * To avoid confusing future readers: none of this is necessary
569 * to load the LDT. The hypervisor only checks this when the
570 * LDT is faulted in due to subsequent descriptor access.
571 */
572
573 for(i = 0; i < entries; i += entries_per_page)
574 set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
575 }
576
xen_free_ldt(struct desc_struct * ldt,unsigned entries)577 static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
578 {
579 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
580 int i;
581
582 for(i = 0; i < entries; i += entries_per_page)
583 set_aliased_prot(ldt + i, PAGE_KERNEL);
584 }
585
xen_set_ldt(const void * addr,unsigned entries)586 static void xen_set_ldt(const void *addr, unsigned entries)
587 {
588 struct mmuext_op *op;
589 struct multicall_space mcs = xen_mc_entry(sizeof(*op));
590
591 trace_xen_cpu_set_ldt(addr, entries);
592
593 op = mcs.args;
594 op->cmd = MMUEXT_SET_LDT;
595 op->arg1.linear_addr = (unsigned long)addr;
596 op->arg2.nr_ents = entries;
597
598 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
599
600 xen_mc_issue(PARAVIRT_LAZY_CPU);
601 }
602
xen_load_gdt(const struct desc_ptr * dtr)603 static void xen_load_gdt(const struct desc_ptr *dtr)
604 {
605 unsigned long va = dtr->address;
606 unsigned int size = dtr->size + 1;
607 unsigned pages = DIV_ROUND_UP(size, PAGE_SIZE);
608 unsigned long frames[pages];
609 int f;
610
611 /*
612 * A GDT can be up to 64k in size, which corresponds to 8192
613 * 8-byte entries, or 16 4k pages..
614 */
615
616 BUG_ON(size > 65536);
617 BUG_ON(va & ~PAGE_MASK);
618
619 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
620 int level;
621 pte_t *ptep;
622 unsigned long pfn, mfn;
623 void *virt;
624
625 /*
626 * The GDT is per-cpu and is in the percpu data area.
627 * That can be virtually mapped, so we need to do a
628 * page-walk to get the underlying MFN for the
629 * hypercall. The page can also be in the kernel's
630 * linear range, so we need to RO that mapping too.
631 */
632 ptep = lookup_address(va, &level);
633 BUG_ON(ptep == NULL);
634
635 pfn = pte_pfn(*ptep);
636 mfn = pfn_to_mfn(pfn);
637 virt = __va(PFN_PHYS(pfn));
638
639 frames[f] = mfn;
640
641 make_lowmem_page_readonly((void *)va);
642 make_lowmem_page_readonly(virt);
643 }
644
645 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
646 BUG();
647 }
648
649 /*
650 * load_gdt for early boot, when the gdt is only mapped once
651 */
xen_load_gdt_boot(const struct desc_ptr * dtr)652 static void __init xen_load_gdt_boot(const struct desc_ptr *dtr)
653 {
654 unsigned long va = dtr->address;
655 unsigned int size = dtr->size + 1;
656 unsigned pages = DIV_ROUND_UP(size, PAGE_SIZE);
657 unsigned long frames[pages];
658 int f;
659
660 /*
661 * A GDT can be up to 64k in size, which corresponds to 8192
662 * 8-byte entries, or 16 4k pages..
663 */
664
665 BUG_ON(size > 65536);
666 BUG_ON(va & ~PAGE_MASK);
667
668 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
669 pte_t pte;
670 unsigned long pfn, mfn;
671
672 pfn = virt_to_pfn(va);
673 mfn = pfn_to_mfn(pfn);
674
675 pte = pfn_pte(pfn, PAGE_KERNEL_RO);
676
677 if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0))
678 BUG();
679
680 frames[f] = mfn;
681 }
682
683 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
684 BUG();
685 }
686
desc_equal(const struct desc_struct * d1,const struct desc_struct * d2)687 static inline bool desc_equal(const struct desc_struct *d1,
688 const struct desc_struct *d2)
689 {
690 return d1->a == d2->a && d1->b == d2->b;
691 }
692
load_TLS_descriptor(struct thread_struct * t,unsigned int cpu,unsigned int i)693 static void load_TLS_descriptor(struct thread_struct *t,
694 unsigned int cpu, unsigned int i)
695 {
696 struct desc_struct *shadow = &per_cpu(shadow_tls_desc, cpu).desc[i];
697 struct desc_struct *gdt;
698 xmaddr_t maddr;
699 struct multicall_space mc;
700
701 if (desc_equal(shadow, &t->tls_array[i]))
702 return;
703
704 *shadow = t->tls_array[i];
705
706 gdt = get_cpu_gdt_table(cpu);
707 maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
708 mc = __xen_mc_entry(0);
709
710 MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
711 }
712
xen_load_tls(struct thread_struct * t,unsigned int cpu)713 static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
714 {
715 /*
716 * XXX sleazy hack: If we're being called in a lazy-cpu zone
717 * and lazy gs handling is enabled, it means we're in a
718 * context switch, and %gs has just been saved. This means we
719 * can zero it out to prevent faults on exit from the
720 * hypervisor if the next process has no %gs. Either way, it
721 * has been saved, and the new value will get loaded properly.
722 * This will go away as soon as Xen has been modified to not
723 * save/restore %gs for normal hypercalls.
724 *
725 * On x86_64, this hack is not used for %gs, because gs points
726 * to KERNEL_GS_BASE (and uses it for PDA references), so we
727 * must not zero %gs on x86_64
728 *
729 * For x86_64, we need to zero %fs, otherwise we may get an
730 * exception between the new %fs descriptor being loaded and
731 * %fs being effectively cleared at __switch_to().
732 */
733 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
734 #ifdef CONFIG_X86_32
735 lazy_load_gs(0);
736 #else
737 loadsegment(fs, 0);
738 #endif
739 }
740
741 xen_mc_batch();
742
743 load_TLS_descriptor(t, cpu, 0);
744 load_TLS_descriptor(t, cpu, 1);
745 load_TLS_descriptor(t, cpu, 2);
746
747 xen_mc_issue(PARAVIRT_LAZY_CPU);
748 }
749
750 #ifdef CONFIG_X86_64
xen_load_gs_index(unsigned int idx)751 static void xen_load_gs_index(unsigned int idx)
752 {
753 if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
754 BUG();
755 }
756 #endif
757
xen_write_ldt_entry(struct desc_struct * dt,int entrynum,const void * ptr)758 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
759 const void *ptr)
760 {
761 xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
762 u64 entry = *(u64 *)ptr;
763
764 trace_xen_cpu_write_ldt_entry(dt, entrynum, entry);
765
766 preempt_disable();
767
768 xen_mc_flush();
769 if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
770 BUG();
771
772 preempt_enable();
773 }
774
cvt_gate_to_trap(int vector,const gate_desc * val,struct trap_info * info)775 static int cvt_gate_to_trap(int vector, const gate_desc *val,
776 struct trap_info *info)
777 {
778 unsigned long addr;
779
780 if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT)
781 return 0;
782
783 info->vector = vector;
784
785 addr = gate_offset(*val);
786 #ifdef CONFIG_X86_64
787 /*
788 * Look for known traps using IST, and substitute them
789 * appropriately. The debugger ones are the only ones we care
790 * about. Xen will handle faults like double_fault,
791 * so we should never see them. Warn if
792 * there's an unexpected IST-using fault handler.
793 */
794 if (addr == (unsigned long)debug)
795 addr = (unsigned long)xen_debug;
796 else if (addr == (unsigned long)int3)
797 addr = (unsigned long)xen_int3;
798 else if (addr == (unsigned long)stack_segment)
799 addr = (unsigned long)xen_stack_segment;
800 else if (addr == (unsigned long)double_fault) {
801 /* Don't need to handle these */
802 return 0;
803 #ifdef CONFIG_X86_MCE
804 } else if (addr == (unsigned long)machine_check) {
805 /*
806 * when xen hypervisor inject vMCE to guest,
807 * use native mce handler to handle it
808 */
809 ;
810 #endif
811 } else if (addr == (unsigned long)nmi)
812 /*
813 * Use the native version as well.
814 */
815 ;
816 else {
817 /* Some other trap using IST? */
818 if (WARN_ON(val->ist != 0))
819 return 0;
820 }
821 #endif /* CONFIG_X86_64 */
822 info->address = addr;
823
824 info->cs = gate_segment(*val);
825 info->flags = val->dpl;
826 /* interrupt gates clear IF */
827 if (val->type == GATE_INTERRUPT)
828 info->flags |= 1 << 2;
829
830 return 1;
831 }
832
833 /* Locations of each CPU's IDT */
834 static DEFINE_PER_CPU(struct desc_ptr, idt_desc);
835
836 /* Set an IDT entry. If the entry is part of the current IDT, then
837 also update Xen. */
xen_write_idt_entry(gate_desc * dt,int entrynum,const gate_desc * g)838 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
839 {
840 unsigned long p = (unsigned long)&dt[entrynum];
841 unsigned long start, end;
842
843 trace_xen_cpu_write_idt_entry(dt, entrynum, g);
844
845 preempt_disable();
846
847 start = __this_cpu_read(idt_desc.address);
848 end = start + __this_cpu_read(idt_desc.size) + 1;
849
850 xen_mc_flush();
851
852 native_write_idt_entry(dt, entrynum, g);
853
854 if (p >= start && (p + 8) <= end) {
855 struct trap_info info[2];
856
857 info[1].address = 0;
858
859 if (cvt_gate_to_trap(entrynum, g, &info[0]))
860 if (HYPERVISOR_set_trap_table(info))
861 BUG();
862 }
863
864 preempt_enable();
865 }
866
xen_convert_trap_info(const struct desc_ptr * desc,struct trap_info * traps)867 static void xen_convert_trap_info(const struct desc_ptr *desc,
868 struct trap_info *traps)
869 {
870 unsigned in, out, count;
871
872 count = (desc->size+1) / sizeof(gate_desc);
873 BUG_ON(count > 256);
874
875 for (in = out = 0; in < count; in++) {
876 gate_desc *entry = (gate_desc*)(desc->address) + in;
877
878 if (cvt_gate_to_trap(in, entry, &traps[out]))
879 out++;
880 }
881 traps[out].address = 0;
882 }
883
xen_copy_trap_info(struct trap_info * traps)884 void xen_copy_trap_info(struct trap_info *traps)
885 {
886 const struct desc_ptr *desc = this_cpu_ptr(&idt_desc);
887
888 xen_convert_trap_info(desc, traps);
889 }
890
891 /* Load a new IDT into Xen. In principle this can be per-CPU, so we
892 hold a spinlock to protect the static traps[] array (static because
893 it avoids allocation, and saves stack space). */
xen_load_idt(const struct desc_ptr * desc)894 static void xen_load_idt(const struct desc_ptr *desc)
895 {
896 static DEFINE_SPINLOCK(lock);
897 static struct trap_info traps[257];
898
899 trace_xen_cpu_load_idt(desc);
900
901 spin_lock(&lock);
902
903 memcpy(this_cpu_ptr(&idt_desc), desc, sizeof(idt_desc));
904
905 xen_convert_trap_info(desc, traps);
906
907 xen_mc_flush();
908 if (HYPERVISOR_set_trap_table(traps))
909 BUG();
910
911 spin_unlock(&lock);
912 }
913
914 /* Write a GDT descriptor entry. Ignore LDT descriptors, since
915 they're handled differently. */
xen_write_gdt_entry(struct desc_struct * dt,int entry,const void * desc,int type)916 static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
917 const void *desc, int type)
918 {
919 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
920
921 preempt_disable();
922
923 switch (type) {
924 case DESC_LDT:
925 case DESC_TSS:
926 /* ignore */
927 break;
928
929 default: {
930 xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]);
931
932 xen_mc_flush();
933 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
934 BUG();
935 }
936
937 }
938
939 preempt_enable();
940 }
941
942 /*
943 * Version of write_gdt_entry for use at early boot-time needed to
944 * update an entry as simply as possible.
945 */
xen_write_gdt_entry_boot(struct desc_struct * dt,int entry,const void * desc,int type)946 static void __init xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
947 const void *desc, int type)
948 {
949 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
950
951 switch (type) {
952 case DESC_LDT:
953 case DESC_TSS:
954 /* ignore */
955 break;
956
957 default: {
958 xmaddr_t maddr = virt_to_machine(&dt[entry]);
959
960 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
961 dt[entry] = *(struct desc_struct *)desc;
962 }
963
964 }
965 }
966
xen_load_sp0(struct tss_struct * tss,struct thread_struct * thread)967 static void xen_load_sp0(struct tss_struct *tss,
968 struct thread_struct *thread)
969 {
970 struct multicall_space mcs;
971
972 mcs = xen_mc_entry(0);
973 MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
974 xen_mc_issue(PARAVIRT_LAZY_CPU);
975 tss->x86_tss.sp0 = thread->sp0;
976 }
977
xen_set_iopl_mask(unsigned mask)978 void xen_set_iopl_mask(unsigned mask)
979 {
980 struct physdev_set_iopl set_iopl;
981
982 /* Force the change at ring 0. */
983 set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
984 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
985 }
986
xen_io_delay(void)987 static void xen_io_delay(void)
988 {
989 }
990
xen_clts(void)991 static void xen_clts(void)
992 {
993 struct multicall_space mcs;
994
995 mcs = xen_mc_entry(0);
996
997 MULTI_fpu_taskswitch(mcs.mc, 0);
998
999 xen_mc_issue(PARAVIRT_LAZY_CPU);
1000 }
1001
1002 static DEFINE_PER_CPU(unsigned long, xen_cr0_value);
1003
xen_read_cr0(void)1004 static unsigned long xen_read_cr0(void)
1005 {
1006 unsigned long cr0 = this_cpu_read(xen_cr0_value);
1007
1008 if (unlikely(cr0 == 0)) {
1009 cr0 = native_read_cr0();
1010 this_cpu_write(xen_cr0_value, cr0);
1011 }
1012
1013 return cr0;
1014 }
1015
xen_write_cr0(unsigned long cr0)1016 static void xen_write_cr0(unsigned long cr0)
1017 {
1018 struct multicall_space mcs;
1019
1020 this_cpu_write(xen_cr0_value, cr0);
1021
1022 /* Only pay attention to cr0.TS; everything else is
1023 ignored. */
1024 mcs = xen_mc_entry(0);
1025
1026 MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
1027
1028 xen_mc_issue(PARAVIRT_LAZY_CPU);
1029 }
1030
xen_write_cr4(unsigned long cr4)1031 static void xen_write_cr4(unsigned long cr4)
1032 {
1033 cr4 &= ~(X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PCE);
1034
1035 native_write_cr4(cr4);
1036 }
1037 #ifdef CONFIG_X86_64
xen_read_cr8(void)1038 static inline unsigned long xen_read_cr8(void)
1039 {
1040 return 0;
1041 }
xen_write_cr8(unsigned long val)1042 static inline void xen_write_cr8(unsigned long val)
1043 {
1044 BUG_ON(val);
1045 }
1046 #endif
1047
xen_read_msr_safe(unsigned int msr,int * err)1048 static u64 xen_read_msr_safe(unsigned int msr, int *err)
1049 {
1050 u64 val;
1051
1052 if (pmu_msr_read(msr, &val, err))
1053 return val;
1054
1055 val = native_read_msr_safe(msr, err);
1056 switch (msr) {
1057 case MSR_IA32_APICBASE:
1058 #ifdef CONFIG_X86_X2APIC
1059 if (!(cpuid_ecx(1) & (1 << (X86_FEATURE_X2APIC & 31))))
1060 #endif
1061 val &= ~X2APIC_ENABLE;
1062 break;
1063 }
1064 return val;
1065 }
1066
xen_write_msr_safe(unsigned int msr,unsigned low,unsigned high)1067 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
1068 {
1069 int ret;
1070
1071 ret = 0;
1072
1073 switch (msr) {
1074 #ifdef CONFIG_X86_64
1075 unsigned which;
1076 u64 base;
1077
1078 case MSR_FS_BASE: which = SEGBASE_FS; goto set;
1079 case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set;
1080 case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set;
1081
1082 set:
1083 base = ((u64)high << 32) | low;
1084 if (HYPERVISOR_set_segment_base(which, base) != 0)
1085 ret = -EIO;
1086 break;
1087 #endif
1088
1089 case MSR_STAR:
1090 case MSR_CSTAR:
1091 case MSR_LSTAR:
1092 case MSR_SYSCALL_MASK:
1093 case MSR_IA32_SYSENTER_CS:
1094 case MSR_IA32_SYSENTER_ESP:
1095 case MSR_IA32_SYSENTER_EIP:
1096 /* Fast syscall setup is all done in hypercalls, so
1097 these are all ignored. Stub them out here to stop
1098 Xen console noise. */
1099 break;
1100
1101 default:
1102 if (!pmu_msr_write(msr, low, high, &ret))
1103 ret = native_write_msr_safe(msr, low, high);
1104 }
1105
1106 return ret;
1107 }
1108
xen_read_msr(unsigned int msr)1109 static u64 xen_read_msr(unsigned int msr)
1110 {
1111 /*
1112 * This will silently swallow a #GP from RDMSR. It may be worth
1113 * changing that.
1114 */
1115 int err;
1116
1117 return xen_read_msr_safe(msr, &err);
1118 }
1119
xen_write_msr(unsigned int msr,unsigned low,unsigned high)1120 static void xen_write_msr(unsigned int msr, unsigned low, unsigned high)
1121 {
1122 /*
1123 * This will silently swallow a #GP from WRMSR. It may be worth
1124 * changing that.
1125 */
1126 xen_write_msr_safe(msr, low, high);
1127 }
1128
xen_setup_shared_info(void)1129 void xen_setup_shared_info(void)
1130 {
1131 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1132 set_fixmap(FIX_PARAVIRT_BOOTMAP,
1133 xen_start_info->shared_info);
1134
1135 HYPERVISOR_shared_info =
1136 (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
1137 } else
1138 HYPERVISOR_shared_info =
1139 (struct shared_info *)__va(xen_start_info->shared_info);
1140
1141 #ifndef CONFIG_SMP
1142 /* In UP this is as good a place as any to set up shared info */
1143 xen_setup_vcpu_info_placement();
1144 #endif
1145
1146 xen_setup_mfn_list_list();
1147 }
1148
1149 /* This is called once we have the cpu_possible_mask */
xen_setup_vcpu_info_placement(void)1150 void xen_setup_vcpu_info_placement(void)
1151 {
1152 int cpu;
1153
1154 for_each_possible_cpu(cpu) {
1155 /* Set up direct vCPU id mapping for PV guests. */
1156 per_cpu(xen_vcpu_id, cpu) = cpu;
1157 xen_vcpu_setup(cpu);
1158 }
1159
1160 /* xen_vcpu_setup managed to place the vcpu_info within the
1161 * percpu area for all cpus, so make use of it. Note that for
1162 * PVH we want to use native IRQ mechanism. */
1163 if (have_vcpu_info_placement && !xen_pvh_domain()) {
1164 pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
1165 pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct);
1166 pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
1167 pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
1168 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
1169 }
1170 }
1171
xen_patch(u8 type,u16 clobbers,void * insnbuf,unsigned long addr,unsigned len)1172 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
1173 unsigned long addr, unsigned len)
1174 {
1175 char *start, *end, *reloc;
1176 unsigned ret;
1177
1178 start = end = reloc = NULL;
1179
1180 #define SITE(op, x) \
1181 case PARAVIRT_PATCH(op.x): \
1182 if (have_vcpu_info_placement) { \
1183 start = (char *)xen_##x##_direct; \
1184 end = xen_##x##_direct_end; \
1185 reloc = xen_##x##_direct_reloc; \
1186 } \
1187 goto patch_site
1188
1189 switch (type) {
1190 SITE(pv_irq_ops, irq_enable);
1191 SITE(pv_irq_ops, irq_disable);
1192 SITE(pv_irq_ops, save_fl);
1193 SITE(pv_irq_ops, restore_fl);
1194 #undef SITE
1195
1196 patch_site:
1197 if (start == NULL || (end-start) > len)
1198 goto default_patch;
1199
1200 ret = paravirt_patch_insns(insnbuf, len, start, end);
1201
1202 /* Note: because reloc is assigned from something that
1203 appears to be an array, gcc assumes it's non-null,
1204 but doesn't know its relationship with start and
1205 end. */
1206 if (reloc > start && reloc < end) {
1207 int reloc_off = reloc - start;
1208 long *relocp = (long *)(insnbuf + reloc_off);
1209 long delta = start - (char *)addr;
1210
1211 *relocp += delta;
1212 }
1213 break;
1214
1215 default_patch:
1216 default:
1217 ret = paravirt_patch_default(type, clobbers, insnbuf,
1218 addr, len);
1219 break;
1220 }
1221
1222 return ret;
1223 }
1224
1225 static const struct pv_info xen_info __initconst = {
1226 .shared_kernel_pmd = 0,
1227
1228 #ifdef CONFIG_X86_64
1229 .extra_user_64bit_cs = FLAT_USER_CS64,
1230 #endif
1231 .name = "Xen",
1232 };
1233
1234 static const struct pv_init_ops xen_init_ops __initconst = {
1235 .patch = xen_patch,
1236 };
1237
1238 static const struct pv_cpu_ops xen_cpu_ops __initconst = {
1239 .cpuid = xen_cpuid,
1240
1241 .set_debugreg = xen_set_debugreg,
1242 .get_debugreg = xen_get_debugreg,
1243
1244 .clts = xen_clts,
1245
1246 .read_cr0 = xen_read_cr0,
1247 .write_cr0 = xen_write_cr0,
1248
1249 .read_cr4 = native_read_cr4,
1250 .write_cr4 = xen_write_cr4,
1251
1252 #ifdef CONFIG_X86_64
1253 .read_cr8 = xen_read_cr8,
1254 .write_cr8 = xen_write_cr8,
1255 #endif
1256
1257 .wbinvd = native_wbinvd,
1258
1259 .read_msr = xen_read_msr,
1260 .write_msr = xen_write_msr,
1261
1262 .read_msr_safe = xen_read_msr_safe,
1263 .write_msr_safe = xen_write_msr_safe,
1264
1265 .read_pmc = xen_read_pmc,
1266
1267 .iret = xen_iret,
1268 #ifdef CONFIG_X86_64
1269 .usergs_sysret64 = xen_sysret64,
1270 #endif
1271
1272 .load_tr_desc = paravirt_nop,
1273 .set_ldt = xen_set_ldt,
1274 .load_gdt = xen_load_gdt,
1275 .load_idt = xen_load_idt,
1276 .load_tls = xen_load_tls,
1277 #ifdef CONFIG_X86_64
1278 .load_gs_index = xen_load_gs_index,
1279 #endif
1280
1281 .alloc_ldt = xen_alloc_ldt,
1282 .free_ldt = xen_free_ldt,
1283
1284 .store_idt = native_store_idt,
1285 .store_tr = xen_store_tr,
1286
1287 .write_ldt_entry = xen_write_ldt_entry,
1288 .write_gdt_entry = xen_write_gdt_entry,
1289 .write_idt_entry = xen_write_idt_entry,
1290 .load_sp0 = xen_load_sp0,
1291
1292 .set_iopl_mask = xen_set_iopl_mask,
1293 .io_delay = xen_io_delay,
1294
1295 /* Xen takes care of %gs when switching to usermode for us */
1296 .swapgs = paravirt_nop,
1297
1298 .start_context_switch = paravirt_start_context_switch,
1299 .end_context_switch = xen_end_context_switch,
1300 };
1301
xen_reboot(int reason)1302 static void xen_reboot(int reason)
1303 {
1304 struct sched_shutdown r = { .reason = reason };
1305 int cpu;
1306
1307 for_each_online_cpu(cpu)
1308 xen_pmu_finish(cpu);
1309
1310 if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
1311 BUG();
1312 }
1313
xen_restart(char * msg)1314 static void xen_restart(char *msg)
1315 {
1316 xen_reboot(SHUTDOWN_reboot);
1317 }
1318
xen_emergency_restart(void)1319 static void xen_emergency_restart(void)
1320 {
1321 xen_reboot(SHUTDOWN_reboot);
1322 }
1323
xen_machine_halt(void)1324 static void xen_machine_halt(void)
1325 {
1326 xen_reboot(SHUTDOWN_poweroff);
1327 }
1328
xen_machine_power_off(void)1329 static void xen_machine_power_off(void)
1330 {
1331 if (pm_power_off)
1332 pm_power_off();
1333 xen_reboot(SHUTDOWN_poweroff);
1334 }
1335
xen_crash_shutdown(struct pt_regs * regs)1336 static void xen_crash_shutdown(struct pt_regs *regs)
1337 {
1338 xen_reboot(SHUTDOWN_crash);
1339 }
1340
1341 static int
xen_panic_event(struct notifier_block * this,unsigned long event,void * ptr)1342 xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
1343 {
1344 if (!kexec_crash_loaded())
1345 xen_reboot(SHUTDOWN_crash);
1346 return NOTIFY_DONE;
1347 }
1348
1349 static struct notifier_block xen_panic_block = {
1350 .notifier_call= xen_panic_event,
1351 .priority = INT_MIN
1352 };
1353
xen_panic_handler_init(void)1354 int xen_panic_handler_init(void)
1355 {
1356 atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block);
1357 return 0;
1358 }
1359
1360 static const struct machine_ops xen_machine_ops __initconst = {
1361 .restart = xen_restart,
1362 .halt = xen_machine_halt,
1363 .power_off = xen_machine_power_off,
1364 .shutdown = xen_machine_halt,
1365 .crash_shutdown = xen_crash_shutdown,
1366 .emergency_restart = xen_emergency_restart,
1367 };
1368
xen_get_nmi_reason(void)1369 static unsigned char xen_get_nmi_reason(void)
1370 {
1371 unsigned char reason = 0;
1372
1373 /* Construct a value which looks like it came from port 0x61. */
1374 if (test_bit(_XEN_NMIREASON_io_error,
1375 &HYPERVISOR_shared_info->arch.nmi_reason))
1376 reason |= NMI_REASON_IOCHK;
1377 if (test_bit(_XEN_NMIREASON_pci_serr,
1378 &HYPERVISOR_shared_info->arch.nmi_reason))
1379 reason |= NMI_REASON_SERR;
1380
1381 return reason;
1382 }
1383
xen_boot_params_init_edd(void)1384 static void __init xen_boot_params_init_edd(void)
1385 {
1386 #if IS_ENABLED(CONFIG_EDD)
1387 struct xen_platform_op op;
1388 struct edd_info *edd_info;
1389 u32 *mbr_signature;
1390 unsigned nr;
1391 int ret;
1392
1393 edd_info = boot_params.eddbuf;
1394 mbr_signature = boot_params.edd_mbr_sig_buffer;
1395
1396 op.cmd = XENPF_firmware_info;
1397
1398 op.u.firmware_info.type = XEN_FW_DISK_INFO;
1399 for (nr = 0; nr < EDDMAXNR; nr++) {
1400 struct edd_info *info = edd_info + nr;
1401
1402 op.u.firmware_info.index = nr;
1403 info->params.length = sizeof(info->params);
1404 set_xen_guest_handle(op.u.firmware_info.u.disk_info.edd_params,
1405 &info->params);
1406 ret = HYPERVISOR_platform_op(&op);
1407 if (ret)
1408 break;
1409
1410 #define C(x) info->x = op.u.firmware_info.u.disk_info.x
1411 C(device);
1412 C(version);
1413 C(interface_support);
1414 C(legacy_max_cylinder);
1415 C(legacy_max_head);
1416 C(legacy_sectors_per_track);
1417 #undef C
1418 }
1419 boot_params.eddbuf_entries = nr;
1420
1421 op.u.firmware_info.type = XEN_FW_DISK_MBR_SIGNATURE;
1422 for (nr = 0; nr < EDD_MBR_SIG_MAX; nr++) {
1423 op.u.firmware_info.index = nr;
1424 ret = HYPERVISOR_platform_op(&op);
1425 if (ret)
1426 break;
1427 mbr_signature[nr] = op.u.firmware_info.u.disk_mbr_signature.mbr_signature;
1428 }
1429 boot_params.edd_mbr_sig_buf_entries = nr;
1430 #endif
1431 }
1432
1433 /*
1434 * Set up the GDT and segment registers for -fstack-protector. Until
1435 * we do this, we have to be careful not to call any stack-protected
1436 * function, which is most of the kernel.
1437 *
1438 * Note, that it is __ref because the only caller of this after init
1439 * is PVH which is not going to use xen_load_gdt_boot or other
1440 * __init functions.
1441 */
xen_setup_gdt(int cpu)1442 static void __ref xen_setup_gdt(int cpu)
1443 {
1444 if (xen_feature(XENFEAT_auto_translated_physmap)) {
1445 #ifdef CONFIG_X86_64
1446 unsigned long dummy;
1447
1448 load_percpu_segment(cpu); /* We need to access per-cpu area */
1449 switch_to_new_gdt(cpu); /* GDT and GS set */
1450
1451 /* We are switching of the Xen provided GDT to our HVM mode
1452 * GDT. The new GDT has __KERNEL_CS with CS.L = 1
1453 * and we are jumping to reload it.
1454 */
1455 asm volatile ("pushq %0\n"
1456 "leaq 1f(%%rip),%0\n"
1457 "pushq %0\n"
1458 "lretq\n"
1459 "1:\n"
1460 : "=&r" (dummy) : "0" (__KERNEL_CS));
1461
1462 /*
1463 * While not needed, we also set the %es, %ds, and %fs
1464 * to zero. We don't care about %ss as it is NULL.
1465 * Strictly speaking this is not needed as Xen zeros those
1466 * out (and also MSR_FS_BASE, MSR_GS_BASE, MSR_KERNEL_GS_BASE)
1467 *
1468 * Linux zeros them in cpu_init() and in secondary_startup_64
1469 * (for BSP).
1470 */
1471 loadsegment(es, 0);
1472 loadsegment(ds, 0);
1473 loadsegment(fs, 0);
1474 #else
1475 /* PVH: TODO Implement. */
1476 BUG();
1477 #endif
1478 return; /* PVH does not need any PV GDT ops. */
1479 }
1480 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
1481 pv_cpu_ops.load_gdt = xen_load_gdt_boot;
1482
1483 setup_stack_canary_segment(0);
1484 switch_to_new_gdt(0);
1485
1486 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry;
1487 pv_cpu_ops.load_gdt = xen_load_gdt;
1488 }
1489
1490 #ifdef CONFIG_XEN_PVH
1491 /*
1492 * A PV guest starts with default flags that are not set for PVH, set them
1493 * here asap.
1494 */
xen_pvh_set_cr_flags(int cpu)1495 static void xen_pvh_set_cr_flags(int cpu)
1496 {
1497
1498 /* Some of these are setup in 'secondary_startup_64'. The others:
1499 * X86_CR0_TS, X86_CR0_PE, X86_CR0_ET are set by Xen for HVM guests
1500 * (which PVH shared codepaths), while X86_CR0_PG is for PVH. */
1501 write_cr0(read_cr0() | X86_CR0_MP | X86_CR0_NE | X86_CR0_WP | X86_CR0_AM);
1502
1503 if (!cpu)
1504 return;
1505 /*
1506 * For BSP, PSE PGE are set in probe_page_size_mask(), for APs
1507 * set them here. For all, OSFXSR OSXMMEXCPT are set in fpu__init_cpu().
1508 */
1509 if (boot_cpu_has(X86_FEATURE_PSE))
1510 cr4_set_bits_and_update_boot(X86_CR4_PSE);
1511
1512 if (boot_cpu_has(X86_FEATURE_PGE))
1513 cr4_set_bits_and_update_boot(X86_CR4_PGE);
1514 }
1515
1516 /*
1517 * Note, that it is ref - because the only caller of this after init
1518 * is PVH which is not going to use xen_load_gdt_boot or other
1519 * __init functions.
1520 */
xen_pvh_secondary_vcpu_init(int cpu)1521 void __ref xen_pvh_secondary_vcpu_init(int cpu)
1522 {
1523 xen_setup_gdt(cpu);
1524 xen_pvh_set_cr_flags(cpu);
1525 }
1526
xen_pvh_early_guest_init(void)1527 static void __init xen_pvh_early_guest_init(void)
1528 {
1529 if (!xen_feature(XENFEAT_auto_translated_physmap))
1530 return;
1531
1532 if (!xen_feature(XENFEAT_hvm_callback_vector))
1533 return;
1534
1535 xen_have_vector_callback = 1;
1536
1537 xen_pvh_early_cpu_init(0, false);
1538 xen_pvh_set_cr_flags(0);
1539
1540 #ifdef CONFIG_X86_32
1541 BUG(); /* PVH: Implement proper support. */
1542 #endif
1543 }
1544 #endif /* CONFIG_XEN_PVH */
1545
xen_dom0_set_legacy_features(void)1546 static void __init xen_dom0_set_legacy_features(void)
1547 {
1548 x86_platform.legacy.rtc = 1;
1549 }
1550
xen_cpuhp_setup(void)1551 static int xen_cpuhp_setup(void)
1552 {
1553 int rc;
1554
1555 rc = cpuhp_setup_state_nocalls(CPUHP_XEN_PREPARE,
1556 "XEN_HVM_GUEST_PREPARE",
1557 xen_cpu_up_prepare, xen_cpu_dead);
1558 if (rc >= 0) {
1559 rc = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
1560 "XEN_HVM_GUEST_ONLINE",
1561 xen_cpu_up_online, NULL);
1562 if (rc < 0)
1563 cpuhp_remove_state_nocalls(CPUHP_XEN_PREPARE);
1564 }
1565
1566 return rc >= 0 ? 0 : rc;
1567 }
1568
1569 /* First C function to be called on Xen boot */
xen_start_kernel(void)1570 asmlinkage __visible void __init xen_start_kernel(void)
1571 {
1572 struct physdev_set_iopl set_iopl;
1573 unsigned long initrd_start = 0;
1574 int rc;
1575
1576 if (!xen_start_info)
1577 return;
1578
1579 xen_domain_type = XEN_PV_DOMAIN;
1580
1581 xen_setup_features();
1582 #ifdef CONFIG_XEN_PVH
1583 xen_pvh_early_guest_init();
1584 #endif
1585 xen_setup_machphys_mapping();
1586
1587 /* Install Xen paravirt ops */
1588 pv_info = xen_info;
1589 pv_init_ops = xen_init_ops;
1590 if (!xen_pvh_domain()) {
1591 pv_cpu_ops = xen_cpu_ops;
1592
1593 x86_platform.get_nmi_reason = xen_get_nmi_reason;
1594 }
1595
1596 if (xen_feature(XENFEAT_auto_translated_physmap))
1597 x86_init.resources.memory_setup = xen_auto_xlated_memory_setup;
1598 else
1599 x86_init.resources.memory_setup = xen_memory_setup;
1600 x86_init.oem.arch_setup = xen_arch_setup;
1601 x86_init.oem.banner = xen_banner;
1602
1603 xen_init_time_ops();
1604
1605 /*
1606 * Set up some pagetable state before starting to set any ptes.
1607 */
1608
1609 xen_init_mmu_ops();
1610
1611 /* Prevent unwanted bits from being set in PTEs. */
1612 __supported_pte_mask &= ~_PAGE_GLOBAL;
1613
1614 /*
1615 * Prevent page tables from being allocated in highmem, even
1616 * if CONFIG_HIGHPTE is enabled.
1617 */
1618 __userpte_alloc_gfp &= ~__GFP_HIGHMEM;
1619
1620 /* Work out if we support NX */
1621 x86_configure_nx();
1622
1623 /* Get mfn list */
1624 xen_build_dynamic_phys_to_machine();
1625
1626 /*
1627 * Set up kernel GDT and segment registers, mainly so that
1628 * -fstack-protector code can be executed.
1629 */
1630 xen_setup_gdt(0);
1631
1632 xen_init_irq_ops();
1633 xen_init_cpuid_mask();
1634
1635 #ifdef CONFIG_X86_LOCAL_APIC
1636 /*
1637 * set up the basic apic ops.
1638 */
1639 xen_init_apic();
1640 #endif
1641
1642 if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
1643 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
1644 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
1645 }
1646
1647 machine_ops = xen_machine_ops;
1648
1649 /*
1650 * The only reliable way to retain the initial address of the
1651 * percpu gdt_page is to remember it here, so we can go and
1652 * mark it RW later, when the initial percpu area is freed.
1653 */
1654 xen_initial_gdt = &per_cpu(gdt_page, 0);
1655
1656 xen_smp_init();
1657
1658 #ifdef CONFIG_ACPI_NUMA
1659 /*
1660 * The pages we from Xen are not related to machine pages, so
1661 * any NUMA information the kernel tries to get from ACPI will
1662 * be meaningless. Prevent it from trying.
1663 */
1664 acpi_numa = -1;
1665 #endif
1666 /* Don't do the full vcpu_info placement stuff until we have a
1667 possible map and a non-dummy shared_info. */
1668 per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1669
1670 WARN_ON(xen_cpuhp_setup());
1671
1672 local_irq_disable();
1673 early_boot_irqs_disabled = true;
1674
1675 xen_raw_console_write("mapping kernel into physical memory\n");
1676 xen_setup_kernel_pagetable((pgd_t *)xen_start_info->pt_base,
1677 xen_start_info->nr_pages);
1678 xen_reserve_special_pages();
1679
1680 /* keep using Xen gdt for now; no urgent need to change it */
1681
1682 #ifdef CONFIG_X86_32
1683 pv_info.kernel_rpl = 1;
1684 if (xen_feature(XENFEAT_supervisor_mode_kernel))
1685 pv_info.kernel_rpl = 0;
1686 #else
1687 pv_info.kernel_rpl = 0;
1688 #endif
1689 /* set the limit of our address space */
1690 xen_reserve_top();
1691
1692 /* PVH: runs at default kernel iopl of 0 */
1693 if (!xen_pvh_domain()) {
1694 /*
1695 * We used to do this in xen_arch_setup, but that is too late
1696 * on AMD were early_cpu_init (run before ->arch_setup()) calls
1697 * early_amd_init which pokes 0xcf8 port.
1698 */
1699 set_iopl.iopl = 1;
1700 rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
1701 if (rc != 0)
1702 xen_raw_printk("physdev_op failed %d\n", rc);
1703 }
1704
1705 #ifdef CONFIG_X86_32
1706 /* set up basic CPUID stuff */
1707 cpu_detect(&new_cpu_data);
1708 set_cpu_cap(&new_cpu_data, X86_FEATURE_FPU);
1709 new_cpu_data.wp_works_ok = 1;
1710 new_cpu_data.x86_capability[CPUID_1_EDX] = cpuid_edx(1);
1711 #endif
1712
1713 if (xen_start_info->mod_start) {
1714 if (xen_start_info->flags & SIF_MOD_START_PFN)
1715 initrd_start = PFN_PHYS(xen_start_info->mod_start);
1716 else
1717 initrd_start = __pa(xen_start_info->mod_start);
1718 }
1719
1720 /* Poke various useful things into boot_params */
1721 boot_params.hdr.type_of_loader = (9 << 4) | 0;
1722 boot_params.hdr.ramdisk_image = initrd_start;
1723 boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
1724 boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
1725 boot_params.hdr.hardware_subarch = X86_SUBARCH_XEN;
1726
1727 if (!xen_initial_domain()) {
1728 add_preferred_console("xenboot", 0, NULL);
1729 add_preferred_console("tty", 0, NULL);
1730 add_preferred_console("hvc", 0, NULL);
1731 if (pci_xen)
1732 x86_init.pci.arch_init = pci_xen_init;
1733 } else {
1734 const struct dom0_vga_console_info *info =
1735 (void *)((char *)xen_start_info +
1736 xen_start_info->console.dom0.info_off);
1737 struct xen_platform_op op = {
1738 .cmd = XENPF_firmware_info,
1739 .interface_version = XENPF_INTERFACE_VERSION,
1740 .u.firmware_info.type = XEN_FW_KBD_SHIFT_FLAGS,
1741 };
1742
1743 x86_platform.set_legacy_features =
1744 xen_dom0_set_legacy_features;
1745 xen_init_vga(info, xen_start_info->console.dom0.info_size);
1746 xen_start_info->console.domU.mfn = 0;
1747 xen_start_info->console.domU.evtchn = 0;
1748
1749 if (HYPERVISOR_platform_op(&op) == 0)
1750 boot_params.kbd_status = op.u.firmware_info.u.kbd_shift_flags;
1751
1752 /* Make sure ACS will be enabled */
1753 pci_request_acs();
1754
1755 xen_acpi_sleep_register();
1756
1757 /* Avoid searching for BIOS MP tables */
1758 x86_init.mpparse.find_smp_config = x86_init_noop;
1759 x86_init.mpparse.get_smp_config = x86_init_uint_noop;
1760
1761 xen_boot_params_init_edd();
1762 }
1763 #ifdef CONFIG_PCI
1764 /* PCI BIOS service won't work from a PV guest. */
1765 pci_probe &= ~PCI_PROBE_BIOS;
1766 #endif
1767 xen_raw_console_write("about to get started...\n");
1768
1769 /* Let's presume PV guests always boot on vCPU with id 0. */
1770 per_cpu(xen_vcpu_id, 0) = 0;
1771
1772 xen_setup_runstate_info(0);
1773
1774 xen_efi_init();
1775
1776 /* Start the world */
1777 #ifdef CONFIG_X86_32
1778 i386_start_kernel();
1779 #else
1780 cr4_init_shadow(); /* 32b kernel does this in i386_start_kernel() */
1781 x86_64_start_reservations((char *)__pa_symbol(&boot_params));
1782 #endif
1783 }
1784
xen_hvm_init_shared_info(void)1785 void __ref xen_hvm_init_shared_info(void)
1786 {
1787 int cpu;
1788 struct xen_add_to_physmap xatp;
1789 static struct shared_info *shared_info_page = 0;
1790
1791 if (!shared_info_page)
1792 shared_info_page = (struct shared_info *)
1793 extend_brk(PAGE_SIZE, PAGE_SIZE);
1794 xatp.domid = DOMID_SELF;
1795 xatp.idx = 0;
1796 xatp.space = XENMAPSPACE_shared_info;
1797 xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
1798 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
1799 BUG();
1800
1801 HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
1802
1803 /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
1804 * page, we use it in the event channel upcall and in some pvclock
1805 * related functions. We don't need the vcpu_info placement
1806 * optimizations because we don't use any pv_mmu or pv_irq op on
1807 * HVM.
1808 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
1809 * online but xen_hvm_init_shared_info is run at resume time too and
1810 * in that case multiple vcpus might be online. */
1811 for_each_online_cpu(cpu) {
1812 /* Leave it to be NULL. */
1813 if (xen_vcpu_nr(cpu) >= MAX_VIRT_CPUS)
1814 continue;
1815 per_cpu(xen_vcpu, cpu) =
1816 &HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
1817 }
1818 }
1819
1820 #ifdef CONFIG_XEN_PVHVM
init_hvm_pv_info(void)1821 static void __init init_hvm_pv_info(void)
1822 {
1823 int major, minor;
1824 uint32_t eax, ebx, ecx, edx, pages, msr, base;
1825 u64 pfn;
1826
1827 base = xen_cpuid_base();
1828 cpuid(base + 1, &eax, &ebx, &ecx, &edx);
1829
1830 major = eax >> 16;
1831 minor = eax & 0xffff;
1832 printk(KERN_INFO "Xen version %d.%d.\n", major, minor);
1833
1834 cpuid(base + 2, &pages, &msr, &ecx, &edx);
1835
1836 pfn = __pa(hypercall_page);
1837 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
1838
1839 xen_setup_features();
1840
1841 cpuid(base + 4, &eax, &ebx, &ecx, &edx);
1842 if (eax & XEN_HVM_CPUID_VCPU_ID_PRESENT)
1843 this_cpu_write(xen_vcpu_id, ebx);
1844 else
1845 this_cpu_write(xen_vcpu_id, smp_processor_id());
1846
1847 pv_info.name = "Xen HVM";
1848
1849 xen_domain_type = XEN_HVM_DOMAIN;
1850 }
1851 #endif
1852
xen_cpu_up_prepare(unsigned int cpu)1853 static int xen_cpu_up_prepare(unsigned int cpu)
1854 {
1855 int rc;
1856
1857 if (xen_hvm_domain()) {
1858 /*
1859 * This can happen if CPU was offlined earlier and
1860 * offlining timed out in common_cpu_die().
1861 */
1862 if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) {
1863 xen_smp_intr_free(cpu);
1864 xen_uninit_lock_cpu(cpu);
1865 }
1866
1867 if (cpu_acpi_id(cpu) != U32_MAX)
1868 per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);
1869 else
1870 per_cpu(xen_vcpu_id, cpu) = cpu;
1871 xen_vcpu_setup(cpu);
1872 }
1873
1874 if (xen_pv_domain() ||
1875 (xen_have_vector_callback &&
1876 xen_feature(XENFEAT_hvm_safe_pvclock)))
1877 xen_setup_timer(cpu);
1878
1879 rc = xen_smp_intr_init(cpu);
1880 if (rc) {
1881 WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n",
1882 cpu, rc);
1883 return rc;
1884 }
1885 return 0;
1886 }
1887
xen_cpu_dead(unsigned int cpu)1888 static int xen_cpu_dead(unsigned int cpu)
1889 {
1890 xen_smp_intr_free(cpu);
1891
1892 if (xen_pv_domain() ||
1893 (xen_have_vector_callback &&
1894 xen_feature(XENFEAT_hvm_safe_pvclock)))
1895 xen_teardown_timer(cpu);
1896
1897 return 0;
1898 }
1899
xen_cpu_up_online(unsigned int cpu)1900 static int xen_cpu_up_online(unsigned int cpu)
1901 {
1902 xen_init_lock_cpu(cpu);
1903 return 0;
1904 }
1905
1906 #ifdef CONFIG_XEN_PVHVM
1907 #ifdef CONFIG_KEXEC_CORE
xen_hvm_shutdown(void)1908 static void xen_hvm_shutdown(void)
1909 {
1910 native_machine_shutdown();
1911 if (kexec_in_progress)
1912 xen_reboot(SHUTDOWN_soft_reset);
1913 }
1914
xen_hvm_crash_shutdown(struct pt_regs * regs)1915 static void xen_hvm_crash_shutdown(struct pt_regs *regs)
1916 {
1917 native_machine_crash_shutdown(regs);
1918 xen_reboot(SHUTDOWN_soft_reset);
1919 }
1920 #endif
1921
xen_hvm_guest_init(void)1922 static void __init xen_hvm_guest_init(void)
1923 {
1924 if (xen_pv_domain())
1925 return;
1926
1927 init_hvm_pv_info();
1928
1929 xen_hvm_init_shared_info();
1930
1931 xen_panic_handler_init();
1932
1933 if (xen_feature(XENFEAT_hvm_callback_vector))
1934 xen_have_vector_callback = 1;
1935 xen_hvm_smp_init();
1936 WARN_ON(xen_cpuhp_setup());
1937 xen_unplug_emulated_devices();
1938 x86_init.irqs.intr_init = xen_init_IRQ;
1939 xen_hvm_init_time_ops();
1940 xen_hvm_init_mmu_ops();
1941 #ifdef CONFIG_KEXEC_CORE
1942 machine_ops.shutdown = xen_hvm_shutdown;
1943 machine_ops.crash_shutdown = xen_hvm_crash_shutdown;
1944 #endif
1945 }
1946 #endif
1947
1948 static bool xen_nopv = false;
xen_parse_nopv(char * arg)1949 static __init int xen_parse_nopv(char *arg)
1950 {
1951 xen_nopv = true;
1952 return 0;
1953 }
1954 early_param("xen_nopv", xen_parse_nopv);
1955
xen_platform(void)1956 static uint32_t __init xen_platform(void)
1957 {
1958 if (xen_nopv)
1959 return 0;
1960
1961 return xen_cpuid_base();
1962 }
1963
xen_hvm_need_lapic(void)1964 bool xen_hvm_need_lapic(void)
1965 {
1966 if (xen_nopv)
1967 return false;
1968 if (xen_pv_domain())
1969 return false;
1970 if (!xen_hvm_domain())
1971 return false;
1972 if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
1973 return false;
1974 return true;
1975 }
1976 EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
1977
xen_set_cpu_features(struct cpuinfo_x86 * c)1978 static void xen_set_cpu_features(struct cpuinfo_x86 *c)
1979 {
1980 if (xen_pv_domain()) {
1981 clear_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
1982 set_cpu_cap(c, X86_FEATURE_XENPV);
1983 }
1984 }
1985
xen_pin_vcpu(int cpu)1986 static void xen_pin_vcpu(int cpu)
1987 {
1988 static bool disable_pinning;
1989 struct sched_pin_override pin_override;
1990 int ret;
1991
1992 if (disable_pinning)
1993 return;
1994
1995 pin_override.pcpu = cpu;
1996 ret = HYPERVISOR_sched_op(SCHEDOP_pin_override, &pin_override);
1997
1998 /* Ignore errors when removing override. */
1999 if (cpu < 0)
2000 return;
2001
2002 switch (ret) {
2003 case -ENOSYS:
2004 pr_warn("Unable to pin on physical cpu %d. In case of problems consider vcpu pinning.\n",
2005 cpu);
2006 disable_pinning = true;
2007 break;
2008 case -EPERM:
2009 WARN(1, "Trying to pin vcpu without having privilege to do so\n");
2010 disable_pinning = true;
2011 break;
2012 case -EINVAL:
2013 case -EBUSY:
2014 pr_warn("Physical cpu %d not available for pinning. Check Xen cpu configuration.\n",
2015 cpu);
2016 break;
2017 case 0:
2018 break;
2019 default:
2020 WARN(1, "rc %d while trying to pin vcpu\n", ret);
2021 disable_pinning = true;
2022 }
2023 }
2024
2025 const struct hypervisor_x86 x86_hyper_xen = {
2026 .name = "Xen",
2027 .detect = xen_platform,
2028 #ifdef CONFIG_XEN_PVHVM
2029 .init_platform = xen_hvm_guest_init,
2030 #endif
2031 .x2apic_available = xen_x2apic_para_available,
2032 .set_cpu_features = xen_set_cpu_features,
2033 .pin_vcpu = xen_pin_vcpu,
2034 };
2035 EXPORT_SYMBOL(x86_hyper_xen);
2036
2037 #ifdef CONFIG_HOTPLUG_CPU
xen_arch_register_cpu(int num)2038 void xen_arch_register_cpu(int num)
2039 {
2040 arch_register_cpu(num);
2041 }
2042 EXPORT_SYMBOL(xen_arch_register_cpu);
2043
xen_arch_unregister_cpu(int num)2044 void xen_arch_unregister_cpu(int num)
2045 {
2046 arch_unregister_cpu(num);
2047 }
2048 EXPORT_SYMBOL(xen_arch_unregister_cpu);
2049 #endif
2050