2 * Core of Xen paravirt_ops implementation.
4 * This file contains the xen_paravirt_ops structure itself, and the
6 * - privileged instructions
11 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
14 #include <linux/cpu.h>
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/smp.h>
18 #include <linux/preempt.h>
19 #include <linux/hardirq.h>
20 #include <linux/percpu.h>
21 #include <linux/delay.h>
22 #include <linux/start_kernel.h>
23 #include <linux/sched.h>
24 #include <linux/kprobes.h>
25 #include <linux/bootmem.h>
26 #include <linux/module.h>
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>
36 #ifdef CONFIG_KEXEC_CORE
37 #include <linux/kexec.h>
41 #include <xen/events.h>
42 #include <xen/interface/xen.h>
43 #include <xen/interface/version.h>
44 #include <xen/interface/physdev.h>
45 #include <xen/interface/vcpu.h>
46 #include <xen/interface/memory.h>
47 #include <xen/interface/nmi.h>
48 #include <xen/interface/xen-mca.h>
49 #include <xen/features.h>
52 #include <xen/hvc-console.h>
55 #include <asm/paravirt.h>
58 #include <asm/xen/pci.h>
59 #include <asm/xen/hypercall.h>
60 #include <asm/xen/hypervisor.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>
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>
81 #include <linux/acpi.h>
83 #include <acpi/pdc_intel.h>
84 #include <acpi/processor.h>
85 #include <xen/interface/platform.h>
91 #include "multicalls.h"
94 EXPORT_SYMBOL_GPL(hypercall_page);
97 * Pointer to the xen_vcpu_info structure or
98 * &HYPERVISOR_shared_info->vcpu_info[cpu]. See xen_hvm_init_shared_info
99 * and xen_vcpu_setup for details. By default it points to share_info->vcpu_info
100 * but if the hypervisor supports VCPUOP_register_vcpu_info then it can point
101 * to xen_vcpu_info. The pointer is used in __xen_evtchn_do_upcall to
102 * acknowledge pending events.
103 * Also more subtly it is used by the patched version of irq enable/disable
104 * e.g. xen_irq_enable_direct and xen_iret in PV mode.
106 * The desire to be able to do those mask/unmask operations as a single
107 * instruction by using the per-cpu offset held in %gs is the real reason
108 * vcpu info is in a per-cpu pointer and the original reason for this
112 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
115 * Per CPU pages used if hypervisor supports VCPUOP_register_vcpu_info
116 * hypercall. This can be used both in PV and PVHVM mode. The structure
117 * overrides the default per_cpu(xen_vcpu, cpu) value.
119 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
121 enum xen_domain_type xen_domain_type = XEN_NATIVE;
122 EXPORT_SYMBOL_GPL(xen_domain_type);
124 unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START;
125 EXPORT_SYMBOL(machine_to_phys_mapping);
126 unsigned long machine_to_phys_nr;
127 EXPORT_SYMBOL(machine_to_phys_nr);
129 struct start_info *xen_start_info;
130 EXPORT_SYMBOL_GPL(xen_start_info);
132 struct shared_info xen_dummy_shared_info;
134 void *xen_initial_gdt;
136 RESERVE_BRK(shared_info_page_brk, PAGE_SIZE);
137 __read_mostly int xen_have_vector_callback;
138 EXPORT_SYMBOL_GPL(xen_have_vector_callback);
141 * Point at some empty memory to start with. We map the real shared_info
142 * page as soon as fixmap is up and running.
144 struct shared_info *HYPERVISOR_shared_info = &xen_dummy_shared_info;
147 * Flag to determine whether vcpu info placement is available on all
148 * VCPUs. We assume it is to start with, and then set it to zero on
149 * the first failure. This is because it can succeed on some VCPUs
150 * and not others, since it can involve hypervisor memory allocation,
151 * or because the guest failed to guarantee all the appropriate
152 * constraints on all VCPUs (ie buffer can't cross a page boundary).
154 * Note that any particular CPU may be using a placed vcpu structure,
155 * but we can only optimise if the all are.
157 * 0: not available, 1: available
159 static int have_vcpu_info_placement = 1;
162 struct desc_struct desc[3];
166 * Updating the 3 TLS descriptors in the GDT on every task switch is
167 * surprisingly expensive so we avoid updating them if they haven't
168 * changed. Since Xen writes different descriptors than the one
169 * passed in the update_descriptor hypercall we keep shadow copies to
172 static DEFINE_PER_CPU(struct tls_descs, shadow_tls_desc);
174 static void clamp_max_cpus(void)
177 if (setup_max_cpus > MAX_VIRT_CPUS)
178 setup_max_cpus = MAX_VIRT_CPUS;
182 static void xen_vcpu_setup(int cpu)
184 struct vcpu_register_vcpu_info info;
186 struct vcpu_info *vcpup;
188 BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
191 * This path is called twice on PVHVM - first during bootup via
192 * smp_init -> xen_hvm_cpu_notify, and then if the VCPU is being
193 * hotplugged: cpu_up -> xen_hvm_cpu_notify.
194 * As we can only do the VCPUOP_register_vcpu_info once lets
195 * not over-write its result.
197 * For PV it is called during restore (xen_vcpu_restore) and bootup
198 * (xen_setup_vcpu_info_placement). The hotplug mechanism does not
201 if (xen_hvm_domain()) {
202 if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu))
205 if (cpu < MAX_VIRT_CPUS)
206 per_cpu(xen_vcpu,cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
208 if (!have_vcpu_info_placement) {
209 if (cpu >= MAX_VIRT_CPUS)
214 vcpup = &per_cpu(xen_vcpu_info, cpu);
215 info.mfn = arbitrary_virt_to_mfn(vcpup);
216 info.offset = offset_in_page(vcpup);
218 /* Check to see if the hypervisor will put the vcpu_info
219 structure where we want it, which allows direct access via
221 N.B. This hypercall can _only_ be called once per CPU. Subsequent
222 calls will error out with -EINVAL. This is due to the fact that
223 hypervisor has no unregister variant and this hypercall does not
224 allow to over-write info.mfn and info.offset.
226 err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
229 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
230 have_vcpu_info_placement = 0;
233 /* This cpu is using the registered vcpu info, even if
234 later ones fail to. */
235 per_cpu(xen_vcpu, cpu) = vcpup;
240 * On restore, set the vcpu placement up again.
241 * If it fails, then we're in a bad state, since
242 * we can't back out from using it...
244 void xen_vcpu_restore(void)
248 for_each_possible_cpu(cpu) {
249 bool other_cpu = (cpu != smp_processor_id());
250 bool is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL);
252 if (other_cpu && is_up &&
253 HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL))
256 xen_setup_runstate_info(cpu);
258 if (have_vcpu_info_placement)
261 if (other_cpu && is_up &&
262 HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
267 static void __init xen_banner(void)
269 unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
270 struct xen_extraversion extra;
271 HYPERVISOR_xen_version(XENVER_extraversion, &extra);
273 pr_info("Booting paravirtualized kernel %son %s\n",
274 xen_feature(XENFEAT_auto_translated_physmap) ?
275 "with PVH extensions " : "", pv_info.name);
276 printk(KERN_INFO "Xen version: %d.%d%s%s\n",
277 version >> 16, version & 0xffff, extra.extraversion,
278 xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
280 /* Check if running on Xen version (major, minor) or later */
282 xen_running_on_version_or_later(unsigned int major, unsigned int minor)
284 unsigned int version;
289 version = HYPERVISOR_xen_version(XENVER_version, NULL);
290 if ((((version >> 16) == major) && ((version & 0xffff) >= minor)) ||
291 ((version >> 16) > major))
296 #define CPUID_THERM_POWER_LEAF 6
297 #define APERFMPERF_PRESENT 0
299 static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
300 static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
302 static __read_mostly unsigned int cpuid_leaf1_ecx_set_mask;
303 static __read_mostly unsigned int cpuid_leaf5_ecx_val;
304 static __read_mostly unsigned int cpuid_leaf5_edx_val;
306 static void xen_cpuid(unsigned int *ax, unsigned int *bx,
307 unsigned int *cx, unsigned int *dx)
309 unsigned maskebx = ~0;
310 unsigned maskecx = ~0;
311 unsigned maskedx = ~0;
314 * Mask out inconvenient features, to try and disable as many
315 * unsupported kernel subsystems as possible.
319 maskecx = cpuid_leaf1_ecx_mask;
320 setecx = cpuid_leaf1_ecx_set_mask;
321 maskedx = cpuid_leaf1_edx_mask;
324 case CPUID_MWAIT_LEAF:
325 /* Synthesize the values.. */
328 *cx = cpuid_leaf5_ecx_val;
329 *dx = cpuid_leaf5_edx_val;
332 case CPUID_THERM_POWER_LEAF:
333 /* Disabling APERFMPERF for kernel usage */
334 maskecx = ~(1 << APERFMPERF_PRESENT);
338 /* Suppress extended topology stuff */
343 asm(XEN_EMULATE_PREFIX "cpuid"
348 : "0" (*ax), "2" (*cx));
357 static bool __init xen_check_mwait(void)
360 struct xen_platform_op op = {
361 .cmd = XENPF_set_processor_pminfo,
362 .u.set_pminfo.id = -1,
363 .u.set_pminfo.type = XEN_PM_PDC,
366 unsigned int ax, bx, cx, dx;
367 unsigned int mwait_mask;
369 /* We need to determine whether it is OK to expose the MWAIT
370 * capability to the kernel to harvest deeper than C3 states from ACPI
371 * _CST using the processor_harvest_xen.c module. For this to work, we
372 * need to gather the MWAIT_LEAF values (which the cstate.c code
373 * checks against). The hypervisor won't expose the MWAIT flag because
374 * it would break backwards compatibility; so we will find out directly
375 * from the hardware and hypercall.
377 if (!xen_initial_domain())
381 * When running under platform earlier than Xen4.2, do not expose
382 * mwait, to avoid the risk of loading native acpi pad driver
384 if (!xen_running_on_version_or_later(4, 2))
390 native_cpuid(&ax, &bx, &cx, &dx);
392 mwait_mask = (1 << (X86_FEATURE_EST % 32)) |
393 (1 << (X86_FEATURE_MWAIT % 32));
395 if ((cx & mwait_mask) != mwait_mask)
398 /* We need to emulate the MWAIT_LEAF and for that we need both
399 * ecx and edx. The hypercall provides only partial information.
402 ax = CPUID_MWAIT_LEAF;
407 native_cpuid(&ax, &bx, &cx, &dx);
409 /* Ask the Hypervisor whether to clear ACPI_PDC_C_C2C3_FFH. If so,
410 * don't expose MWAIT_LEAF and let ACPI pick the IOPORT version of C3.
412 buf[0] = ACPI_PDC_REVISION_ID;
414 buf[2] = (ACPI_PDC_C_CAPABILITY_SMP | ACPI_PDC_EST_CAPABILITY_SWSMP);
416 set_xen_guest_handle(op.u.set_pminfo.pdc, buf);
418 if ((HYPERVISOR_dom0_op(&op) == 0) &&
419 (buf[2] & (ACPI_PDC_C_C1_FFH | ACPI_PDC_C_C2C3_FFH))) {
420 cpuid_leaf5_ecx_val = cx;
421 cpuid_leaf5_edx_val = dx;
428 static void __init xen_init_cpuid_mask(void)
430 unsigned int ax, bx, cx, dx;
431 unsigned int xsave_mask;
433 cpuid_leaf1_edx_mask =
434 ~((1 << X86_FEATURE_MTRR) | /* disable MTRR */
435 (1 << X86_FEATURE_ACC)); /* thermal monitoring */
437 if (!xen_initial_domain())
438 cpuid_leaf1_edx_mask &=
439 ~((1 << X86_FEATURE_ACPI)); /* disable ACPI */
441 cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_X2APIC % 32));
445 cpuid(1, &ax, &bx, &cx, &dx);
448 (1 << (X86_FEATURE_XSAVE % 32)) |
449 (1 << (X86_FEATURE_OSXSAVE % 32));
451 /* Xen will set CR4.OSXSAVE if supported and not disabled by force */
452 if ((cx & xsave_mask) != xsave_mask)
453 cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */
454 if (xen_check_mwait())
455 cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32));
458 static void xen_set_debugreg(int reg, unsigned long val)
460 HYPERVISOR_set_debugreg(reg, val);
463 static unsigned long xen_get_debugreg(int reg)
465 return HYPERVISOR_get_debugreg(reg);
468 static void xen_end_context_switch(struct task_struct *next)
471 paravirt_end_context_switch(next);
474 static unsigned long xen_store_tr(void)
480 * Set the page permissions for a particular virtual address. If the
481 * address is a vmalloc mapping (or other non-linear mapping), then
482 * find the linear mapping of the page and also set its protections to
485 static void set_aliased_prot(void *v, pgprot_t prot)
494 ptep = lookup_address((unsigned long)v, &level);
495 BUG_ON(ptep == NULL);
497 pfn = pte_pfn(*ptep);
498 page = pfn_to_page(pfn);
500 pte = pfn_pte(pfn, prot);
503 * Careful: update_va_mapping() will fail if the virtual address
504 * we're poking isn't populated in the page tables. We don't
505 * need to worry about the direct map (that's always in the page
506 * tables), but we need to be careful about vmap space. In
507 * particular, the top level page table can lazily propagate
508 * entries between processes, so if we've switched mms since we
509 * vmapped the target in the first place, we might not have the
510 * top-level page table entry populated.
512 * We disable preemption because we want the same mm active when
513 * we probe the target and when we issue the hypercall. We'll
514 * have the same nominal mm, but if we're a kernel thread, lazy
515 * mm dropping could change our pgd.
517 * Out of an abundance of caution, this uses __get_user() to fault
518 * in the target address just in case there's some obscure case
519 * in which the target address isn't readable.
524 pagefault_disable(); /* Avoid warnings due to being atomic. */
525 __get_user(dummy, (unsigned char __user __force *)v);
528 if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
531 if (!PageHighMem(page)) {
532 void *av = __va(PFN_PHYS(pfn));
535 if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
543 static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
545 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
549 * We need to mark the all aliases of the LDT pages RO. We
550 * don't need to call vm_flush_aliases(), though, since that's
551 * only responsible for flushing aliases out the TLBs, not the
552 * page tables, and Xen will flush the TLB for us if needed.
554 * To avoid confusing future readers: none of this is necessary
555 * to load the LDT. The hypervisor only checks this when the
556 * LDT is faulted in due to subsequent descriptor access.
559 for(i = 0; i < entries; i += entries_per_page)
560 set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
563 static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
565 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
568 for(i = 0; i < entries; i += entries_per_page)
569 set_aliased_prot(ldt + i, PAGE_KERNEL);
572 static void xen_set_ldt(const void *addr, unsigned entries)
574 struct mmuext_op *op;
575 struct multicall_space mcs = xen_mc_entry(sizeof(*op));
577 trace_xen_cpu_set_ldt(addr, entries);
580 op->cmd = MMUEXT_SET_LDT;
581 op->arg1.linear_addr = (unsigned long)addr;
582 op->arg2.nr_ents = entries;
584 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
586 xen_mc_issue(PARAVIRT_LAZY_CPU);
589 static void xen_load_gdt(const struct desc_ptr *dtr)
591 unsigned long va = dtr->address;
592 unsigned int size = dtr->size + 1;
593 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
594 unsigned long frames[pages];
598 * A GDT can be up to 64k in size, which corresponds to 8192
599 * 8-byte entries, or 16 4k pages..
602 BUG_ON(size > 65536);
603 BUG_ON(va & ~PAGE_MASK);
605 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
608 unsigned long pfn, mfn;
612 * The GDT is per-cpu and is in the percpu data area.
613 * That can be virtually mapped, so we need to do a
614 * page-walk to get the underlying MFN for the
615 * hypercall. The page can also be in the kernel's
616 * linear range, so we need to RO that mapping too.
618 ptep = lookup_address(va, &level);
619 BUG_ON(ptep == NULL);
621 pfn = pte_pfn(*ptep);
622 mfn = pfn_to_mfn(pfn);
623 virt = __va(PFN_PHYS(pfn));
627 make_lowmem_page_readonly((void *)va);
628 make_lowmem_page_readonly(virt);
631 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
636 * load_gdt for early boot, when the gdt is only mapped once
638 static void __init xen_load_gdt_boot(const struct desc_ptr *dtr)
640 unsigned long va = dtr->address;
641 unsigned int size = dtr->size + 1;
642 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
643 unsigned long frames[pages];
647 * A GDT can be up to 64k in size, which corresponds to 8192
648 * 8-byte entries, or 16 4k pages..
651 BUG_ON(size > 65536);
652 BUG_ON(va & ~PAGE_MASK);
654 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
656 unsigned long pfn, mfn;
658 pfn = virt_to_pfn(va);
659 mfn = pfn_to_mfn(pfn);
661 pte = pfn_pte(pfn, PAGE_KERNEL_RO);
663 if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0))
669 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
673 static inline bool desc_equal(const struct desc_struct *d1,
674 const struct desc_struct *d2)
676 return d1->a == d2->a && d1->b == d2->b;
679 static void load_TLS_descriptor(struct thread_struct *t,
680 unsigned int cpu, unsigned int i)
682 struct desc_struct *shadow = &per_cpu(shadow_tls_desc, cpu).desc[i];
683 struct desc_struct *gdt;
685 struct multicall_space mc;
687 if (desc_equal(shadow, &t->tls_array[i]))
690 *shadow = t->tls_array[i];
692 gdt = get_cpu_gdt_table(cpu);
693 maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
694 mc = __xen_mc_entry(0);
696 MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
699 static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
702 * XXX sleazy hack: If we're being called in a lazy-cpu zone
703 * and lazy gs handling is enabled, it means we're in a
704 * context switch, and %gs has just been saved. This means we
705 * can zero it out to prevent faults on exit from the
706 * hypervisor if the next process has no %gs. Either way, it
707 * has been saved, and the new value will get loaded properly.
708 * This will go away as soon as Xen has been modified to not
709 * save/restore %gs for normal hypercalls.
711 * On x86_64, this hack is not used for %gs, because gs points
712 * to KERNEL_GS_BASE (and uses it for PDA references), so we
713 * must not zero %gs on x86_64
715 * For x86_64, we need to zero %fs, otherwise we may get an
716 * exception between the new %fs descriptor being loaded and
717 * %fs being effectively cleared at __switch_to().
719 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
729 load_TLS_descriptor(t, cpu, 0);
730 load_TLS_descriptor(t, cpu, 1);
731 load_TLS_descriptor(t, cpu, 2);
733 xen_mc_issue(PARAVIRT_LAZY_CPU);
737 static void xen_load_gs_index(unsigned int idx)
739 if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
744 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
747 xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
748 u64 entry = *(u64 *)ptr;
750 trace_xen_cpu_write_ldt_entry(dt, entrynum, entry);
755 if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
761 static int cvt_gate_to_trap(int vector, const gate_desc *val,
762 struct trap_info *info)
766 if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT)
769 info->vector = vector;
771 addr = gate_offset(*val);
774 * Look for known traps using IST, and substitute them
775 * appropriately. The debugger ones are the only ones we care
776 * about. Xen will handle faults like double_fault,
777 * so we should never see them. Warn if
778 * there's an unexpected IST-using fault handler.
780 if (addr == (unsigned long)debug)
781 addr = (unsigned long)xen_debug;
782 else if (addr == (unsigned long)int3)
783 addr = (unsigned long)xen_int3;
784 else if (addr == (unsigned long)stack_segment)
785 addr = (unsigned long)xen_stack_segment;
786 else if (addr == (unsigned long)double_fault) {
787 /* Don't need to handle these */
789 #ifdef CONFIG_X86_MCE
790 } else if (addr == (unsigned long)machine_check) {
792 * when xen hypervisor inject vMCE to guest,
793 * use native mce handler to handle it
797 } else if (addr == (unsigned long)nmi)
799 * Use the native version as well.
803 /* Some other trap using IST? */
804 if (WARN_ON(val->ist != 0))
807 #endif /* CONFIG_X86_64 */
808 info->address = addr;
810 info->cs = gate_segment(*val);
811 info->flags = val->dpl;
812 /* interrupt gates clear IF */
813 if (val->type == GATE_INTERRUPT)
814 info->flags |= 1 << 2;
819 /* Locations of each CPU's IDT */
820 static DEFINE_PER_CPU(struct desc_ptr, idt_desc);
822 /* Set an IDT entry. If the entry is part of the current IDT, then
824 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
826 unsigned long p = (unsigned long)&dt[entrynum];
827 unsigned long start, end;
829 trace_xen_cpu_write_idt_entry(dt, entrynum, g);
833 start = __this_cpu_read(idt_desc.address);
834 end = start + __this_cpu_read(idt_desc.size) + 1;
838 native_write_idt_entry(dt, entrynum, g);
840 if (p >= start && (p + 8) <= end) {
841 struct trap_info info[2];
845 if (cvt_gate_to_trap(entrynum, g, &info[0]))
846 if (HYPERVISOR_set_trap_table(info))
853 static void xen_convert_trap_info(const struct desc_ptr *desc,
854 struct trap_info *traps)
856 unsigned in, out, count;
858 count = (desc->size+1) / sizeof(gate_desc);
861 for (in = out = 0; in < count; in++) {
862 gate_desc *entry = (gate_desc*)(desc->address) + in;
864 if (cvt_gate_to_trap(in, entry, &traps[out]))
867 traps[out].address = 0;
870 void xen_copy_trap_info(struct trap_info *traps)
872 const struct desc_ptr *desc = this_cpu_ptr(&idt_desc);
874 xen_convert_trap_info(desc, traps);
877 /* Load a new IDT into Xen. In principle this can be per-CPU, so we
878 hold a spinlock to protect the static traps[] array (static because
879 it avoids allocation, and saves stack space). */
880 static void xen_load_idt(const struct desc_ptr *desc)
882 static DEFINE_SPINLOCK(lock);
883 static struct trap_info traps[257];
885 trace_xen_cpu_load_idt(desc);
889 memcpy(this_cpu_ptr(&idt_desc), desc, sizeof(idt_desc));
891 xen_convert_trap_info(desc, traps);
894 if (HYPERVISOR_set_trap_table(traps))
900 /* Write a GDT descriptor entry. Ignore LDT descriptors, since
901 they're handled differently. */
902 static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
903 const void *desc, int type)
905 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
916 xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]);
919 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
929 * Version of write_gdt_entry for use at early boot-time needed to
930 * update an entry as simply as possible.
932 static void __init xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
933 const void *desc, int type)
935 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
944 xmaddr_t maddr = virt_to_machine(&dt[entry]);
946 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
947 dt[entry] = *(struct desc_struct *)desc;
953 static void xen_load_sp0(struct tss_struct *tss,
954 struct thread_struct *thread)
956 struct multicall_space mcs;
958 mcs = xen_mc_entry(0);
959 MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
960 xen_mc_issue(PARAVIRT_LAZY_CPU);
961 tss->x86_tss.sp0 = thread->sp0;
964 static void xen_set_iopl_mask(unsigned mask)
966 struct physdev_set_iopl set_iopl;
968 /* Force the change at ring 0. */
969 set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
970 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
973 static void xen_io_delay(void)
977 static void xen_clts(void)
979 struct multicall_space mcs;
981 mcs = xen_mc_entry(0);
983 MULTI_fpu_taskswitch(mcs.mc, 0);
985 xen_mc_issue(PARAVIRT_LAZY_CPU);
988 static DEFINE_PER_CPU(unsigned long, xen_cr0_value);
990 static unsigned long xen_read_cr0(void)
992 unsigned long cr0 = this_cpu_read(xen_cr0_value);
994 if (unlikely(cr0 == 0)) {
995 cr0 = native_read_cr0();
996 this_cpu_write(xen_cr0_value, cr0);
1002 static void xen_write_cr0(unsigned long cr0)
1004 struct multicall_space mcs;
1006 this_cpu_write(xen_cr0_value, cr0);
1008 /* Only pay attention to cr0.TS; everything else is
1010 mcs = xen_mc_entry(0);
1012 MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
1014 xen_mc_issue(PARAVIRT_LAZY_CPU);
1017 static void xen_write_cr4(unsigned long cr4)
1019 cr4 &= ~(X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PCE);
1021 native_write_cr4(cr4);
1023 #ifdef CONFIG_X86_64
1024 static inline unsigned long xen_read_cr8(void)
1028 static inline void xen_write_cr8(unsigned long val)
1034 static u64 xen_read_msr_safe(unsigned int msr, int *err)
1038 if (pmu_msr_read(msr, &val, err))
1041 val = native_read_msr_safe(msr, err);
1043 case MSR_IA32_APICBASE:
1044 #ifdef CONFIG_X86_X2APIC
1045 if (!(cpuid_ecx(1) & (1 << (X86_FEATURE_X2APIC & 31))))
1047 val &= ~X2APIC_ENABLE;
1053 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
1060 #ifdef CONFIG_X86_64
1064 case MSR_FS_BASE: which = SEGBASE_FS; goto set;
1065 case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set;
1066 case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set;
1069 base = ((u64)high << 32) | low;
1070 if (HYPERVISOR_set_segment_base(which, base) != 0)
1078 case MSR_SYSCALL_MASK:
1079 case MSR_IA32_SYSENTER_CS:
1080 case MSR_IA32_SYSENTER_ESP:
1081 case MSR_IA32_SYSENTER_EIP:
1082 /* Fast syscall setup is all done in hypercalls, so
1083 these are all ignored. Stub them out here to stop
1084 Xen console noise. */
1088 if (!pmu_msr_write(msr, low, high, &ret))
1089 ret = native_write_msr_safe(msr, low, high);
1095 void xen_setup_shared_info(void)
1097 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1098 set_fixmap(FIX_PARAVIRT_BOOTMAP,
1099 xen_start_info->shared_info);
1101 HYPERVISOR_shared_info =
1102 (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
1104 HYPERVISOR_shared_info =
1105 (struct shared_info *)__va(xen_start_info->shared_info);
1108 /* In UP this is as good a place as any to set up shared info */
1109 xen_setup_vcpu_info_placement();
1112 xen_setup_mfn_list_list();
1115 /* This is called once we have the cpu_possible_mask */
1116 void xen_setup_vcpu_info_placement(void)
1120 for_each_possible_cpu(cpu)
1121 xen_vcpu_setup(cpu);
1123 /* xen_vcpu_setup managed to place the vcpu_info within the
1124 * percpu area for all cpus, so make use of it. Note that for
1125 * PVH we want to use native IRQ mechanism. */
1126 if (have_vcpu_info_placement && !xen_pvh_domain()) {
1127 pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
1128 pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct);
1129 pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
1130 pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
1131 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
1135 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
1136 unsigned long addr, unsigned len)
1138 char *start, *end, *reloc;
1141 start = end = reloc = NULL;
1143 #define SITE(op, x) \
1144 case PARAVIRT_PATCH(op.x): \
1145 if (have_vcpu_info_placement) { \
1146 start = (char *)xen_##x##_direct; \
1147 end = xen_##x##_direct_end; \
1148 reloc = xen_##x##_direct_reloc; \
1153 SITE(pv_irq_ops, irq_enable);
1154 SITE(pv_irq_ops, irq_disable);
1155 SITE(pv_irq_ops, save_fl);
1156 SITE(pv_irq_ops, restore_fl);
1160 if (start == NULL || (end-start) > len)
1163 ret = paravirt_patch_insns(insnbuf, len, start, end);
1165 /* Note: because reloc is assigned from something that
1166 appears to be an array, gcc assumes it's non-null,
1167 but doesn't know its relationship with start and
1169 if (reloc > start && reloc < end) {
1170 int reloc_off = reloc - start;
1171 long *relocp = (long *)(insnbuf + reloc_off);
1172 long delta = start - (char *)addr;
1180 ret = paravirt_patch_default(type, clobbers, insnbuf,
1188 static const struct pv_info xen_info __initconst = {
1189 .paravirt_enabled = 1,
1190 .shared_kernel_pmd = 0,
1192 #ifdef CONFIG_X86_64
1193 .extra_user_64bit_cs = FLAT_USER_CS64,
1199 static const struct pv_init_ops xen_init_ops __initconst = {
1203 static const struct pv_cpu_ops xen_cpu_ops __initconst = {
1206 .set_debugreg = xen_set_debugreg,
1207 .get_debugreg = xen_get_debugreg,
1211 .read_cr0 = xen_read_cr0,
1212 .write_cr0 = xen_write_cr0,
1214 .read_cr4 = native_read_cr4,
1215 .read_cr4_safe = native_read_cr4_safe,
1216 .write_cr4 = xen_write_cr4,
1218 #ifdef CONFIG_X86_64
1219 .read_cr8 = xen_read_cr8,
1220 .write_cr8 = xen_write_cr8,
1223 .wbinvd = native_wbinvd,
1225 .read_msr = xen_read_msr_safe,
1226 .write_msr = xen_write_msr_safe,
1228 .read_pmc = xen_read_pmc,
1231 #ifdef CONFIG_X86_64
1232 .usergs_sysret32 = xen_sysret32,
1233 .usergs_sysret64 = xen_sysret64,
1235 .irq_enable_sysexit = xen_sysexit,
1238 .load_tr_desc = paravirt_nop,
1239 .set_ldt = xen_set_ldt,
1240 .load_gdt = xen_load_gdt,
1241 .load_idt = xen_load_idt,
1242 .load_tls = xen_load_tls,
1243 #ifdef CONFIG_X86_64
1244 .load_gs_index = xen_load_gs_index,
1247 .alloc_ldt = xen_alloc_ldt,
1248 .free_ldt = xen_free_ldt,
1250 .store_idt = native_store_idt,
1251 .store_tr = xen_store_tr,
1253 .write_ldt_entry = xen_write_ldt_entry,
1254 .write_gdt_entry = xen_write_gdt_entry,
1255 .write_idt_entry = xen_write_idt_entry,
1256 .load_sp0 = xen_load_sp0,
1258 .set_iopl_mask = xen_set_iopl_mask,
1259 .io_delay = xen_io_delay,
1261 /* Xen takes care of %gs when switching to usermode for us */
1262 .swapgs = paravirt_nop,
1264 .start_context_switch = paravirt_start_context_switch,
1265 .end_context_switch = xen_end_context_switch,
1268 static const struct pv_apic_ops xen_apic_ops __initconst = {
1269 #ifdef CONFIG_X86_LOCAL_APIC
1270 .startup_ipi_hook = paravirt_nop,
1274 static void xen_reboot(int reason)
1276 struct sched_shutdown r = { .reason = reason };
1279 for_each_online_cpu(cpu)
1280 xen_pmu_finish(cpu);
1282 if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
1286 static void xen_restart(char *msg)
1288 xen_reboot(SHUTDOWN_reboot);
1291 static void xen_emergency_restart(void)
1293 xen_reboot(SHUTDOWN_reboot);
1296 static void xen_machine_halt(void)
1298 xen_reboot(SHUTDOWN_poweroff);
1301 static void xen_machine_power_off(void)
1305 xen_reboot(SHUTDOWN_poweroff);
1308 static void xen_crash_shutdown(struct pt_regs *regs)
1310 xen_reboot(SHUTDOWN_crash);
1314 xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
1316 xen_reboot(SHUTDOWN_crash);
1320 static struct notifier_block xen_panic_block = {
1321 .notifier_call= xen_panic_event,
1325 int xen_panic_handler_init(void)
1327 atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block);
1331 static const struct machine_ops xen_machine_ops __initconst = {
1332 .restart = xen_restart,
1333 .halt = xen_machine_halt,
1334 .power_off = xen_machine_power_off,
1335 .shutdown = xen_machine_halt,
1336 .crash_shutdown = xen_crash_shutdown,
1337 .emergency_restart = xen_emergency_restart,
1340 static unsigned char xen_get_nmi_reason(void)
1342 unsigned char reason = 0;
1344 /* Construct a value which looks like it came from port 0x61. */
1345 if (test_bit(_XEN_NMIREASON_io_error,
1346 &HYPERVISOR_shared_info->arch.nmi_reason))
1347 reason |= NMI_REASON_IOCHK;
1348 if (test_bit(_XEN_NMIREASON_pci_serr,
1349 &HYPERVISOR_shared_info->arch.nmi_reason))
1350 reason |= NMI_REASON_SERR;
1355 static void __init xen_boot_params_init_edd(void)
1357 #if IS_ENABLED(CONFIG_EDD)
1358 struct xen_platform_op op;
1359 struct edd_info *edd_info;
1364 edd_info = boot_params.eddbuf;
1365 mbr_signature = boot_params.edd_mbr_sig_buffer;
1367 op.cmd = XENPF_firmware_info;
1369 op.u.firmware_info.type = XEN_FW_DISK_INFO;
1370 for (nr = 0; nr < EDDMAXNR; nr++) {
1371 struct edd_info *info = edd_info + nr;
1373 op.u.firmware_info.index = nr;
1374 info->params.length = sizeof(info->params);
1375 set_xen_guest_handle(op.u.firmware_info.u.disk_info.edd_params,
1377 ret = HYPERVISOR_dom0_op(&op);
1381 #define C(x) info->x = op.u.firmware_info.u.disk_info.x
1384 C(interface_support);
1385 C(legacy_max_cylinder);
1387 C(legacy_sectors_per_track);
1390 boot_params.eddbuf_entries = nr;
1392 op.u.firmware_info.type = XEN_FW_DISK_MBR_SIGNATURE;
1393 for (nr = 0; nr < EDD_MBR_SIG_MAX; nr++) {
1394 op.u.firmware_info.index = nr;
1395 ret = HYPERVISOR_dom0_op(&op);
1398 mbr_signature[nr] = op.u.firmware_info.u.disk_mbr_signature.mbr_signature;
1400 boot_params.edd_mbr_sig_buf_entries = nr;
1405 * Set up the GDT and segment registers for -fstack-protector. Until
1406 * we do this, we have to be careful not to call any stack-protected
1407 * function, which is most of the kernel.
1409 * Note, that it is __ref because the only caller of this after init
1410 * is PVH which is not going to use xen_load_gdt_boot or other
1413 static void __ref xen_setup_gdt(int cpu)
1415 if (xen_feature(XENFEAT_auto_translated_physmap)) {
1416 #ifdef CONFIG_X86_64
1417 unsigned long dummy;
1419 load_percpu_segment(cpu); /* We need to access per-cpu area */
1420 switch_to_new_gdt(cpu); /* GDT and GS set */
1422 /* We are switching of the Xen provided GDT to our HVM mode
1423 * GDT. The new GDT has __KERNEL_CS with CS.L = 1
1424 * and we are jumping to reload it.
1426 asm volatile ("pushq %0\n"
1427 "leaq 1f(%%rip),%0\n"
1431 : "=&r" (dummy) : "0" (__KERNEL_CS));
1434 * While not needed, we also set the %es, %ds, and %fs
1435 * to zero. We don't care about %ss as it is NULL.
1436 * Strictly speaking this is not needed as Xen zeros those
1437 * out (and also MSR_FS_BASE, MSR_GS_BASE, MSR_KERNEL_GS_BASE)
1439 * Linux zeros them in cpu_init() and in secondary_startup_64
1446 /* PVH: TODO Implement. */
1449 return; /* PVH does not need any PV GDT ops. */
1451 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
1452 pv_cpu_ops.load_gdt = xen_load_gdt_boot;
1454 setup_stack_canary_segment(0);
1455 switch_to_new_gdt(0);
1457 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry;
1458 pv_cpu_ops.load_gdt = xen_load_gdt;
1461 #ifdef CONFIG_XEN_PVH
1463 * A PV guest starts with default flags that are not set for PVH, set them
1466 static void xen_pvh_set_cr_flags(int cpu)
1469 /* Some of these are setup in 'secondary_startup_64'. The others:
1470 * X86_CR0_TS, X86_CR0_PE, X86_CR0_ET are set by Xen for HVM guests
1471 * (which PVH shared codepaths), while X86_CR0_PG is for PVH. */
1472 write_cr0(read_cr0() | X86_CR0_MP | X86_CR0_NE | X86_CR0_WP | X86_CR0_AM);
1477 * For BSP, PSE PGE are set in probe_page_size_mask(), for APs
1478 * set them here. For all, OSFXSR OSXMMEXCPT are set in fpu__init_cpu().
1481 cr4_set_bits_and_update_boot(X86_CR4_PSE);
1484 cr4_set_bits_and_update_boot(X86_CR4_PGE);
1488 * Note, that it is ref - because the only caller of this after init
1489 * is PVH which is not going to use xen_load_gdt_boot or other
1492 void __ref xen_pvh_secondary_vcpu_init(int cpu)
1495 xen_pvh_set_cr_flags(cpu);
1498 static void __init xen_pvh_early_guest_init(void)
1500 if (!xen_feature(XENFEAT_auto_translated_physmap))
1503 if (!xen_feature(XENFEAT_hvm_callback_vector))
1506 xen_have_vector_callback = 1;
1508 xen_pvh_early_cpu_init(0, false);
1509 xen_pvh_set_cr_flags(0);
1511 #ifdef CONFIG_X86_32
1512 BUG(); /* PVH: Implement proper support. */
1515 #endif /* CONFIG_XEN_PVH */
1517 /* First C function to be called on Xen boot */
1518 asmlinkage __visible void __init xen_start_kernel(void)
1520 struct physdev_set_iopl set_iopl;
1521 unsigned long initrd_start = 0;
1525 if (!xen_start_info)
1528 xen_domain_type = XEN_PV_DOMAIN;
1530 xen_setup_features();
1531 #ifdef CONFIG_XEN_PVH
1532 xen_pvh_early_guest_init();
1534 xen_setup_machphys_mapping();
1536 /* Install Xen paravirt ops */
1538 pv_init_ops = xen_init_ops;
1539 pv_apic_ops = xen_apic_ops;
1540 if (!xen_pvh_domain()) {
1541 pv_cpu_ops = xen_cpu_ops;
1543 x86_platform.get_nmi_reason = xen_get_nmi_reason;
1546 if (xen_feature(XENFEAT_auto_translated_physmap))
1547 x86_init.resources.memory_setup = xen_auto_xlated_memory_setup;
1549 x86_init.resources.memory_setup = xen_memory_setup;
1550 x86_init.oem.arch_setup = xen_arch_setup;
1551 x86_init.oem.banner = xen_banner;
1553 xen_init_time_ops();
1556 * Set up some pagetable state before starting to set any ptes.
1561 /* Prevent unwanted bits from being set in PTEs. */
1562 __supported_pte_mask &= ~_PAGE_GLOBAL;
1565 * Prevent page tables from being allocated in highmem, even
1566 * if CONFIG_HIGHPTE is enabled.
1568 __userpte_alloc_gfp &= ~__GFP_HIGHMEM;
1570 /* Work out if we support NX */
1574 xen_build_dynamic_phys_to_machine();
1577 * Set up kernel GDT and segment registers, mainly so that
1578 * -fstack-protector code can be executed.
1583 xen_init_cpuid_mask();
1585 #ifdef CONFIG_X86_LOCAL_APIC
1587 * set up the basic apic ops.
1592 if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
1593 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
1594 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
1597 machine_ops = xen_machine_ops;
1600 * The only reliable way to retain the initial address of the
1601 * percpu gdt_page is to remember it here, so we can go and
1602 * mark it RW later, when the initial percpu area is freed.
1604 xen_initial_gdt = &per_cpu(gdt_page, 0);
1608 #ifdef CONFIG_ACPI_NUMA
1610 * The pages we from Xen are not related to machine pages, so
1611 * any NUMA information the kernel tries to get from ACPI will
1612 * be meaningless. Prevent it from trying.
1616 /* Don't do the full vcpu_info placement stuff until we have a
1617 possible map and a non-dummy shared_info. */
1618 per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1620 local_irq_disable();
1621 early_boot_irqs_disabled = true;
1623 xen_raw_console_write("mapping kernel into physical memory\n");
1624 xen_setup_kernel_pagetable((pgd_t *)xen_start_info->pt_base,
1625 xen_start_info->nr_pages);
1626 xen_reserve_special_pages();
1629 * Modify the cache mode translation tables to match Xen's PAT
1632 rdmsrl(MSR_IA32_CR_PAT, pat);
1633 pat_init_cache_modes(pat);
1635 /* keep using Xen gdt for now; no urgent need to change it */
1637 #ifdef CONFIG_X86_32
1638 pv_info.kernel_rpl = 1;
1639 if (xen_feature(XENFEAT_supervisor_mode_kernel))
1640 pv_info.kernel_rpl = 0;
1642 pv_info.kernel_rpl = 0;
1644 /* set the limit of our address space */
1647 /* PVH: runs at default kernel iopl of 0 */
1648 if (!xen_pvh_domain()) {
1650 * We used to do this in xen_arch_setup, but that is too late
1651 * on AMD were early_cpu_init (run before ->arch_setup()) calls
1652 * early_amd_init which pokes 0xcf8 port.
1655 rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
1657 xen_raw_printk("physdev_op failed %d\n", rc);
1660 #ifdef CONFIG_X86_32
1661 /* set up basic CPUID stuff */
1662 cpu_detect(&new_cpu_data);
1663 set_cpu_cap(&new_cpu_data, X86_FEATURE_FPU);
1664 new_cpu_data.wp_works_ok = 1;
1665 new_cpu_data.x86_capability[0] = cpuid_edx(1);
1668 if (xen_start_info->mod_start) {
1669 if (xen_start_info->flags & SIF_MOD_START_PFN)
1670 initrd_start = PFN_PHYS(xen_start_info->mod_start);
1672 initrd_start = __pa(xen_start_info->mod_start);
1675 /* Poke various useful things into boot_params */
1676 boot_params.hdr.type_of_loader = (9 << 4) | 0;
1677 boot_params.hdr.ramdisk_image = initrd_start;
1678 boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
1679 boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
1681 if (!xen_initial_domain()) {
1682 add_preferred_console("xenboot", 0, NULL);
1683 add_preferred_console("tty", 0, NULL);
1684 add_preferred_console("hvc", 0, NULL);
1686 x86_init.pci.arch_init = pci_xen_init;
1688 const struct dom0_vga_console_info *info =
1689 (void *)((char *)xen_start_info +
1690 xen_start_info->console.dom0.info_off);
1691 struct xen_platform_op op = {
1692 .cmd = XENPF_firmware_info,
1693 .interface_version = XENPF_INTERFACE_VERSION,
1694 .u.firmware_info.type = XEN_FW_KBD_SHIFT_FLAGS,
1697 xen_init_vga(info, xen_start_info->console.dom0.info_size);
1698 xen_start_info->console.domU.mfn = 0;
1699 xen_start_info->console.domU.evtchn = 0;
1701 if (HYPERVISOR_dom0_op(&op) == 0)
1702 boot_params.kbd_status = op.u.firmware_info.u.kbd_shift_flags;
1704 /* Make sure ACS will be enabled */
1707 xen_acpi_sleep_register();
1709 /* Avoid searching for BIOS MP tables */
1710 x86_init.mpparse.find_smp_config = x86_init_noop;
1711 x86_init.mpparse.get_smp_config = x86_init_uint_noop;
1713 xen_boot_params_init_edd();
1716 /* PCI BIOS service won't work from a PV guest. */
1717 pci_probe &= ~PCI_PROBE_BIOS;
1719 xen_raw_console_write("about to get started...\n");
1721 xen_setup_runstate_info(0);
1725 /* Start the world */
1726 #ifdef CONFIG_X86_32
1727 i386_start_kernel();
1729 cr4_init_shadow(); /* 32b kernel does this in i386_start_kernel() */
1730 x86_64_start_reservations((char *)__pa_symbol(&boot_params));
1734 void __ref xen_hvm_init_shared_info(void)
1737 struct xen_add_to_physmap xatp;
1738 static struct shared_info *shared_info_page = 0;
1740 if (!shared_info_page)
1741 shared_info_page = (struct shared_info *)
1742 extend_brk(PAGE_SIZE, PAGE_SIZE);
1743 xatp.domid = DOMID_SELF;
1745 xatp.space = XENMAPSPACE_shared_info;
1746 xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
1747 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
1750 HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
1752 /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
1753 * page, we use it in the event channel upcall and in some pvclock
1754 * related functions. We don't need the vcpu_info placement
1755 * optimizations because we don't use any pv_mmu or pv_irq op on
1757 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
1758 * online but xen_hvm_init_shared_info is run at resume time too and
1759 * in that case multiple vcpus might be online. */
1760 for_each_online_cpu(cpu) {
1761 /* Leave it to be NULL. */
1762 if (cpu >= MAX_VIRT_CPUS)
1764 per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
1768 #ifdef CONFIG_XEN_PVHVM
1769 static void __init init_hvm_pv_info(void)
1772 uint32_t eax, ebx, ecx, edx, pages, msr, base;
1775 base = xen_cpuid_base();
1776 cpuid(base + 1, &eax, &ebx, &ecx, &edx);
1779 minor = eax & 0xffff;
1780 printk(KERN_INFO "Xen version %d.%d.\n", major, minor);
1782 cpuid(base + 2, &pages, &msr, &ecx, &edx);
1784 pfn = __pa(hypercall_page);
1785 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
1787 xen_setup_features();
1789 pv_info.name = "Xen HVM";
1791 xen_domain_type = XEN_HVM_DOMAIN;
1794 static int xen_hvm_cpu_notify(struct notifier_block *self, unsigned long action,
1797 int cpu = (long)hcpu;
1799 case CPU_UP_PREPARE:
1800 xen_vcpu_setup(cpu);
1801 if (xen_have_vector_callback) {
1802 if (xen_feature(XENFEAT_hvm_safe_pvclock))
1803 xen_setup_timer(cpu);
1812 static struct notifier_block xen_hvm_cpu_notifier = {
1813 .notifier_call = xen_hvm_cpu_notify,
1816 #ifdef CONFIG_KEXEC_CORE
1817 static void xen_hvm_shutdown(void)
1819 native_machine_shutdown();
1820 if (kexec_in_progress)
1821 xen_reboot(SHUTDOWN_soft_reset);
1824 static void xen_hvm_crash_shutdown(struct pt_regs *regs)
1826 native_machine_crash_shutdown(regs);
1827 xen_reboot(SHUTDOWN_soft_reset);
1831 static void __init xen_hvm_guest_init(void)
1833 if (xen_pv_domain())
1838 xen_hvm_init_shared_info();
1840 xen_panic_handler_init();
1842 if (xen_feature(XENFEAT_hvm_callback_vector))
1843 xen_have_vector_callback = 1;
1845 register_cpu_notifier(&xen_hvm_cpu_notifier);
1846 xen_unplug_emulated_devices();
1847 x86_init.irqs.intr_init = xen_init_IRQ;
1848 xen_hvm_init_time_ops();
1849 xen_hvm_init_mmu_ops();
1850 #ifdef CONFIG_KEXEC_CORE
1851 machine_ops.shutdown = xen_hvm_shutdown;
1852 machine_ops.crash_shutdown = xen_hvm_crash_shutdown;
1857 static bool xen_nopv = false;
1858 static __init int xen_parse_nopv(char *arg)
1863 early_param("xen_nopv", xen_parse_nopv);
1865 static uint32_t __init xen_platform(void)
1870 return xen_cpuid_base();
1873 bool xen_hvm_need_lapic(void)
1877 if (xen_pv_domain())
1879 if (!xen_hvm_domain())
1881 if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
1885 EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
1887 static void xen_set_cpu_features(struct cpuinfo_x86 *c)
1889 if (xen_pv_domain())
1890 clear_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
1893 const struct hypervisor_x86 x86_hyper_xen = {
1895 .detect = xen_platform,
1896 #ifdef CONFIG_XEN_PVHVM
1897 .init_platform = xen_hvm_guest_init,
1899 .x2apic_available = xen_x2apic_para_available,
1900 .set_cpu_features = xen_set_cpu_features,
1902 EXPORT_SYMBOL(x86_hyper_xen);
1904 #ifdef CONFIG_HOTPLUG_CPU
1905 void xen_arch_register_cpu(int num)
1907 arch_register_cpu(num);
1909 EXPORT_SYMBOL(xen_arch_register_cpu);
1911 void xen_arch_unregister_cpu(int num)
1913 arch_unregister_cpu(num);
1915 EXPORT_SYMBOL(xen_arch_unregister_cpu);