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>
80 #include <linux/acpi.h>
82 #include <acpi/pdc_intel.h>
83 #include <acpi/processor.h>
84 #include <xen/interface/platform.h>
90 #include "multicalls.h"
93 EXPORT_SYMBOL_GPL(hypercall_page);
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.
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
111 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
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.
118 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
120 enum xen_domain_type xen_domain_type = XEN_NATIVE;
121 EXPORT_SYMBOL_GPL(xen_domain_type);
123 unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START;
124 EXPORT_SYMBOL(machine_to_phys_mapping);
125 unsigned long machine_to_phys_nr;
126 EXPORT_SYMBOL(machine_to_phys_nr);
128 struct start_info *xen_start_info;
129 EXPORT_SYMBOL_GPL(xen_start_info);
131 struct shared_info xen_dummy_shared_info;
133 void *xen_initial_gdt;
135 RESERVE_BRK(shared_info_page_brk, PAGE_SIZE);
136 __read_mostly int xen_have_vector_callback;
137 EXPORT_SYMBOL_GPL(xen_have_vector_callback);
140 * Point at some empty memory to start with. We map the real shared_info
141 * page as soon as fixmap is up and running.
143 struct shared_info *HYPERVISOR_shared_info = &xen_dummy_shared_info;
146 * Flag to determine whether vcpu info placement is available on all
147 * VCPUs. We assume it is to start with, and then set it to zero on
148 * the first failure. This is because it can succeed on some VCPUs
149 * and not others, since it can involve hypervisor memory allocation,
150 * or because the guest failed to guarantee all the appropriate
151 * constraints on all VCPUs (ie buffer can't cross a page boundary).
153 * Note that any particular CPU may be using a placed vcpu structure,
154 * but we can only optimise if the all are.
156 * 0: not available, 1: available
158 static int have_vcpu_info_placement = 1;
161 struct desc_struct desc[3];
165 * Updating the 3 TLS descriptors in the GDT on every task switch is
166 * surprisingly expensive so we avoid updating them if they haven't
167 * changed. Since Xen writes different descriptors than the one
168 * passed in the update_descriptor hypercall we keep shadow copies to
171 static DEFINE_PER_CPU(struct tls_descs, shadow_tls_desc);
173 static void clamp_max_cpus(void)
176 if (setup_max_cpus > MAX_VIRT_CPUS)
177 setup_max_cpus = MAX_VIRT_CPUS;
181 static void xen_vcpu_setup(int cpu)
183 struct vcpu_register_vcpu_info info;
185 struct vcpu_info *vcpup;
187 BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
190 * This path is called twice on PVHVM - first during bootup via
191 * smp_init -> xen_hvm_cpu_notify, and then if the VCPU is being
192 * hotplugged: cpu_up -> xen_hvm_cpu_notify.
193 * As we can only do the VCPUOP_register_vcpu_info once lets
194 * not over-write its result.
196 * For PV it is called during restore (xen_vcpu_restore) and bootup
197 * (xen_setup_vcpu_info_placement). The hotplug mechanism does not
200 if (xen_hvm_domain()) {
201 if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu))
204 if (cpu < MAX_VIRT_CPUS)
205 per_cpu(xen_vcpu,cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
207 if (!have_vcpu_info_placement) {
208 if (cpu >= MAX_VIRT_CPUS)
213 vcpup = &per_cpu(xen_vcpu_info, cpu);
214 info.mfn = arbitrary_virt_to_mfn(vcpup);
215 info.offset = offset_in_page(vcpup);
217 /* Check to see if the hypervisor will put the vcpu_info
218 structure where we want it, which allows direct access via
220 N.B. This hypercall can _only_ be called once per CPU. Subsequent
221 calls will error out with -EINVAL. This is due to the fact that
222 hypervisor has no unregister variant and this hypercall does not
223 allow to over-write info.mfn and info.offset.
225 err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
228 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
229 have_vcpu_info_placement = 0;
232 /* This cpu is using the registered vcpu info, even if
233 later ones fail to. */
234 per_cpu(xen_vcpu, cpu) = vcpup;
239 * On restore, set the vcpu placement up again.
240 * If it fails, then we're in a bad state, since
241 * we can't back out from using it...
243 void xen_vcpu_restore(void)
247 for_each_possible_cpu(cpu) {
248 bool other_cpu = (cpu != smp_processor_id());
249 bool is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL);
251 if (other_cpu && is_up &&
252 HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL))
255 xen_setup_runstate_info(cpu);
257 if (have_vcpu_info_placement)
260 if (other_cpu && is_up &&
261 HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
266 static void __init xen_banner(void)
268 unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
269 struct xen_extraversion extra;
270 HYPERVISOR_xen_version(XENVER_extraversion, &extra);
272 pr_info("Booting paravirtualized kernel %son %s\n",
273 xen_feature(XENFEAT_auto_translated_physmap) ?
274 "with PVH extensions " : "", pv_info.name);
275 printk(KERN_INFO "Xen version: %d.%d%s%s\n",
276 version >> 16, version & 0xffff, extra.extraversion,
277 xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
279 /* Check if running on Xen version (major, minor) or later */
281 xen_running_on_version_or_later(unsigned int major, unsigned int minor)
283 unsigned int version;
288 version = HYPERVISOR_xen_version(XENVER_version, NULL);
289 if ((((version >> 16) == major) && ((version & 0xffff) >= minor)) ||
290 ((version >> 16) > major))
295 #define CPUID_THERM_POWER_LEAF 6
296 #define APERFMPERF_PRESENT 0
298 static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
299 static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
301 static __read_mostly unsigned int cpuid_leaf1_ecx_set_mask;
302 static __read_mostly unsigned int cpuid_leaf5_ecx_val;
303 static __read_mostly unsigned int cpuid_leaf5_edx_val;
305 static void xen_cpuid(unsigned int *ax, unsigned int *bx,
306 unsigned int *cx, unsigned int *dx)
308 unsigned maskebx = ~0;
309 unsigned maskecx = ~0;
310 unsigned maskedx = ~0;
313 * Mask out inconvenient features, to try and disable as many
314 * unsupported kernel subsystems as possible.
318 maskecx = cpuid_leaf1_ecx_mask;
319 setecx = cpuid_leaf1_ecx_set_mask;
320 maskedx = cpuid_leaf1_edx_mask;
323 case CPUID_MWAIT_LEAF:
324 /* Synthesize the values.. */
327 *cx = cpuid_leaf5_ecx_val;
328 *dx = cpuid_leaf5_edx_val;
331 case CPUID_THERM_POWER_LEAF:
332 /* Disabling APERFMPERF for kernel usage */
333 maskecx = ~(1 << APERFMPERF_PRESENT);
337 /* Suppress extended topology stuff */
342 asm(XEN_EMULATE_PREFIX "cpuid"
347 : "0" (*ax), "2" (*cx));
356 static bool __init xen_check_mwait(void)
359 struct xen_platform_op op = {
360 .cmd = XENPF_set_processor_pminfo,
361 .u.set_pminfo.id = -1,
362 .u.set_pminfo.type = XEN_PM_PDC,
365 unsigned int ax, bx, cx, dx;
366 unsigned int mwait_mask;
368 /* We need to determine whether it is OK to expose the MWAIT
369 * capability to the kernel to harvest deeper than C3 states from ACPI
370 * _CST using the processor_harvest_xen.c module. For this to work, we
371 * need to gather the MWAIT_LEAF values (which the cstate.c code
372 * checks against). The hypervisor won't expose the MWAIT flag because
373 * it would break backwards compatibility; so we will find out directly
374 * from the hardware and hypercall.
376 if (!xen_initial_domain())
380 * When running under platform earlier than Xen4.2, do not expose
381 * mwait, to avoid the risk of loading native acpi pad driver
383 if (!xen_running_on_version_or_later(4, 2))
389 native_cpuid(&ax, &bx, &cx, &dx);
391 mwait_mask = (1 << (X86_FEATURE_EST % 32)) |
392 (1 << (X86_FEATURE_MWAIT % 32));
394 if ((cx & mwait_mask) != mwait_mask)
397 /* We need to emulate the MWAIT_LEAF and for that we need both
398 * ecx and edx. The hypercall provides only partial information.
401 ax = CPUID_MWAIT_LEAF;
406 native_cpuid(&ax, &bx, &cx, &dx);
408 /* Ask the Hypervisor whether to clear ACPI_PDC_C_C2C3_FFH. If so,
409 * don't expose MWAIT_LEAF and let ACPI pick the IOPORT version of C3.
411 buf[0] = ACPI_PDC_REVISION_ID;
413 buf[2] = (ACPI_PDC_C_CAPABILITY_SMP | ACPI_PDC_EST_CAPABILITY_SWSMP);
415 set_xen_guest_handle(op.u.set_pminfo.pdc, buf);
417 if ((HYPERVISOR_dom0_op(&op) == 0) &&
418 (buf[2] & (ACPI_PDC_C_C1_FFH | ACPI_PDC_C_C2C3_FFH))) {
419 cpuid_leaf5_ecx_val = cx;
420 cpuid_leaf5_edx_val = dx;
427 static void __init xen_init_cpuid_mask(void)
429 unsigned int ax, bx, cx, dx;
430 unsigned int xsave_mask;
432 cpuid_leaf1_edx_mask =
433 ~((1 << X86_FEATURE_MTRR) | /* disable MTRR */
434 (1 << X86_FEATURE_ACC)); /* thermal monitoring */
436 if (!xen_initial_domain())
437 cpuid_leaf1_edx_mask &=
438 ~((1 << X86_FEATURE_ACPI)); /* disable ACPI */
440 cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_X2APIC % 32));
444 cpuid(1, &ax, &bx, &cx, &dx);
447 (1 << (X86_FEATURE_XSAVE % 32)) |
448 (1 << (X86_FEATURE_OSXSAVE % 32));
450 /* Xen will set CR4.OSXSAVE if supported and not disabled by force */
451 if ((cx & xsave_mask) != xsave_mask)
452 cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */
453 if (xen_check_mwait())
454 cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32));
457 static void xen_set_debugreg(int reg, unsigned long val)
459 HYPERVISOR_set_debugreg(reg, val);
462 static unsigned long xen_get_debugreg(int reg)
464 return HYPERVISOR_get_debugreg(reg);
467 static void xen_end_context_switch(struct task_struct *next)
470 paravirt_end_context_switch(next);
473 static unsigned long xen_store_tr(void)
479 * Set the page permissions for a particular virtual address. If the
480 * address is a vmalloc mapping (or other non-linear mapping), then
481 * find the linear mapping of the page and also set its protections to
484 static void set_aliased_prot(void *v, pgprot_t prot)
493 ptep = lookup_address((unsigned long)v, &level);
494 BUG_ON(ptep == NULL);
496 pfn = pte_pfn(*ptep);
497 page = pfn_to_page(pfn);
499 pte = pfn_pte(pfn, prot);
502 * Careful: update_va_mapping() will fail if the virtual address
503 * we're poking isn't populated in the page tables. We don't
504 * need to worry about the direct map (that's always in the page
505 * tables), but we need to be careful about vmap space. In
506 * particular, the top level page table can lazily propagate
507 * entries between processes, so if we've switched mms since we
508 * vmapped the target in the first place, we might not have the
509 * top-level page table entry populated.
511 * We disable preemption because we want the same mm active when
512 * we probe the target and when we issue the hypercall. We'll
513 * have the same nominal mm, but if we're a kernel thread, lazy
514 * mm dropping could change our pgd.
516 * Out of an abundance of caution, this uses __get_user() to fault
517 * in the target address just in case there's some obscure case
518 * in which the target address isn't readable.
523 pagefault_disable(); /* Avoid warnings due to being atomic. */
524 __get_user(dummy, (unsigned char __user __force *)v);
527 if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
530 if (!PageHighMem(page)) {
531 void *av = __va(PFN_PHYS(pfn));
534 if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
542 static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
544 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
548 * We need to mark the all aliases of the LDT pages RO. We
549 * don't need to call vm_flush_aliases(), though, since that's
550 * only responsible for flushing aliases out the TLBs, not the
551 * page tables, and Xen will flush the TLB for us if needed.
553 * To avoid confusing future readers: none of this is necessary
554 * to load the LDT. The hypervisor only checks this when the
555 * LDT is faulted in due to subsequent descriptor access.
558 for(i = 0; i < entries; i += entries_per_page)
559 set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
562 static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
564 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
567 for(i = 0; i < entries; i += entries_per_page)
568 set_aliased_prot(ldt + i, PAGE_KERNEL);
571 static void xen_set_ldt(const void *addr, unsigned entries)
573 struct mmuext_op *op;
574 struct multicall_space mcs = xen_mc_entry(sizeof(*op));
576 trace_xen_cpu_set_ldt(addr, entries);
579 op->cmd = MMUEXT_SET_LDT;
580 op->arg1.linear_addr = (unsigned long)addr;
581 op->arg2.nr_ents = entries;
583 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
585 xen_mc_issue(PARAVIRT_LAZY_CPU);
588 static void xen_load_gdt(const struct desc_ptr *dtr)
590 unsigned long va = dtr->address;
591 unsigned int size = dtr->size + 1;
592 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
593 unsigned long frames[pages];
597 * A GDT can be up to 64k in size, which corresponds to 8192
598 * 8-byte entries, or 16 4k pages..
601 BUG_ON(size > 65536);
602 BUG_ON(va & ~PAGE_MASK);
604 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
607 unsigned long pfn, mfn;
611 * The GDT is per-cpu and is in the percpu data area.
612 * That can be virtually mapped, so we need to do a
613 * page-walk to get the underlying MFN for the
614 * hypercall. The page can also be in the kernel's
615 * linear range, so we need to RO that mapping too.
617 ptep = lookup_address(va, &level);
618 BUG_ON(ptep == NULL);
620 pfn = pte_pfn(*ptep);
621 mfn = pfn_to_mfn(pfn);
622 virt = __va(PFN_PHYS(pfn));
626 make_lowmem_page_readonly((void *)va);
627 make_lowmem_page_readonly(virt);
630 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
635 * load_gdt for early boot, when the gdt is only mapped once
637 static void __init xen_load_gdt_boot(const struct desc_ptr *dtr)
639 unsigned long va = dtr->address;
640 unsigned int size = dtr->size + 1;
641 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
642 unsigned long frames[pages];
646 * A GDT can be up to 64k in size, which corresponds to 8192
647 * 8-byte entries, or 16 4k pages..
650 BUG_ON(size > 65536);
651 BUG_ON(va & ~PAGE_MASK);
653 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
655 unsigned long pfn, mfn;
657 pfn = virt_to_pfn(va);
658 mfn = pfn_to_mfn(pfn);
660 pte = pfn_pte(pfn, PAGE_KERNEL_RO);
662 if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0))
668 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
672 static inline bool desc_equal(const struct desc_struct *d1,
673 const struct desc_struct *d2)
675 return d1->a == d2->a && d1->b == d2->b;
678 static void load_TLS_descriptor(struct thread_struct *t,
679 unsigned int cpu, unsigned int i)
681 struct desc_struct *shadow = &per_cpu(shadow_tls_desc, cpu).desc[i];
682 struct desc_struct *gdt;
684 struct multicall_space mc;
686 if (desc_equal(shadow, &t->tls_array[i]))
689 *shadow = t->tls_array[i];
691 gdt = get_cpu_gdt_table(cpu);
692 maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
693 mc = __xen_mc_entry(0);
695 MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
698 static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
701 * XXX sleazy hack: If we're being called in a lazy-cpu zone
702 * and lazy gs handling is enabled, it means we're in a
703 * context switch, and %gs has just been saved. This means we
704 * can zero it out to prevent faults on exit from the
705 * hypervisor if the next process has no %gs. Either way, it
706 * has been saved, and the new value will get loaded properly.
707 * This will go away as soon as Xen has been modified to not
708 * save/restore %gs for normal hypercalls.
710 * On x86_64, this hack is not used for %gs, because gs points
711 * to KERNEL_GS_BASE (and uses it for PDA references), so we
712 * must not zero %gs on x86_64
714 * For x86_64, we need to zero %fs, otherwise we may get an
715 * exception between the new %fs descriptor being loaded and
716 * %fs being effectively cleared at __switch_to().
718 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
728 load_TLS_descriptor(t, cpu, 0);
729 load_TLS_descriptor(t, cpu, 1);
730 load_TLS_descriptor(t, cpu, 2);
732 xen_mc_issue(PARAVIRT_LAZY_CPU);
736 static void xen_load_gs_index(unsigned int idx)
738 if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
743 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
746 xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
747 u64 entry = *(u64 *)ptr;
749 trace_xen_cpu_write_ldt_entry(dt, entrynum, entry);
754 if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
760 static int cvt_gate_to_trap(int vector, const gate_desc *val,
761 struct trap_info *info)
765 if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT)
768 info->vector = vector;
770 addr = gate_offset(*val);
773 * Look for known traps using IST, and substitute them
774 * appropriately. The debugger ones are the only ones we care
775 * about. Xen will handle faults like double_fault,
776 * so we should never see them. Warn if
777 * there's an unexpected IST-using fault handler.
779 if (addr == (unsigned long)debug)
780 addr = (unsigned long)xen_debug;
781 else if (addr == (unsigned long)int3)
782 addr = (unsigned long)xen_int3;
783 else if (addr == (unsigned long)stack_segment)
784 addr = (unsigned long)xen_stack_segment;
785 else if (addr == (unsigned long)double_fault) {
786 /* Don't need to handle these */
788 #ifdef CONFIG_X86_MCE
789 } else if (addr == (unsigned long)machine_check) {
791 * when xen hypervisor inject vMCE to guest,
792 * use native mce handler to handle it
796 } else if (addr == (unsigned long)nmi)
798 * Use the native version as well.
802 /* Some other trap using IST? */
803 if (WARN_ON(val->ist != 0))
806 #endif /* CONFIG_X86_64 */
807 info->address = addr;
809 info->cs = gate_segment(*val);
810 info->flags = val->dpl;
811 /* interrupt gates clear IF */
812 if (val->type == GATE_INTERRUPT)
813 info->flags |= 1 << 2;
818 /* Locations of each CPU's IDT */
819 static DEFINE_PER_CPU(struct desc_ptr, idt_desc);
821 /* Set an IDT entry. If the entry is part of the current IDT, then
823 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
825 unsigned long p = (unsigned long)&dt[entrynum];
826 unsigned long start, end;
828 trace_xen_cpu_write_idt_entry(dt, entrynum, g);
832 start = __this_cpu_read(idt_desc.address);
833 end = start + __this_cpu_read(idt_desc.size) + 1;
837 native_write_idt_entry(dt, entrynum, g);
839 if (p >= start && (p + 8) <= end) {
840 struct trap_info info[2];
844 if (cvt_gate_to_trap(entrynum, g, &info[0]))
845 if (HYPERVISOR_set_trap_table(info))
852 static void xen_convert_trap_info(const struct desc_ptr *desc,
853 struct trap_info *traps)
855 unsigned in, out, count;
857 count = (desc->size+1) / sizeof(gate_desc);
860 for (in = out = 0; in < count; in++) {
861 gate_desc *entry = (gate_desc*)(desc->address) + in;
863 if (cvt_gate_to_trap(in, entry, &traps[out]))
866 traps[out].address = 0;
869 void xen_copy_trap_info(struct trap_info *traps)
871 const struct desc_ptr *desc = this_cpu_ptr(&idt_desc);
873 xen_convert_trap_info(desc, traps);
876 /* Load a new IDT into Xen. In principle this can be per-CPU, so we
877 hold a spinlock to protect the static traps[] array (static because
878 it avoids allocation, and saves stack space). */
879 static void xen_load_idt(const struct desc_ptr *desc)
881 static DEFINE_SPINLOCK(lock);
882 static struct trap_info traps[257];
884 trace_xen_cpu_load_idt(desc);
888 memcpy(this_cpu_ptr(&idt_desc), desc, sizeof(idt_desc));
890 xen_convert_trap_info(desc, traps);
893 if (HYPERVISOR_set_trap_table(traps))
899 /* Write a GDT descriptor entry. Ignore LDT descriptors, since
900 they're handled differently. */
901 static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
902 const void *desc, int type)
904 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
915 xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]);
918 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
928 * Version of write_gdt_entry for use at early boot-time needed to
929 * update an entry as simply as possible.
931 static void __init xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
932 const void *desc, int type)
934 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
943 xmaddr_t maddr = virt_to_machine(&dt[entry]);
945 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
946 dt[entry] = *(struct desc_struct *)desc;
952 static void xen_load_sp0(struct tss_struct *tss,
953 struct thread_struct *thread)
955 struct multicall_space mcs;
957 mcs = xen_mc_entry(0);
958 MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
959 xen_mc_issue(PARAVIRT_LAZY_CPU);
960 tss->x86_tss.sp0 = thread->sp0;
963 static void xen_set_iopl_mask(unsigned mask)
965 struct physdev_set_iopl set_iopl;
967 /* Force the change at ring 0. */
968 set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
969 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
972 static void xen_io_delay(void)
976 static void xen_clts(void)
978 struct multicall_space mcs;
980 mcs = xen_mc_entry(0);
982 MULTI_fpu_taskswitch(mcs.mc, 0);
984 xen_mc_issue(PARAVIRT_LAZY_CPU);
987 static DEFINE_PER_CPU(unsigned long, xen_cr0_value);
989 static unsigned long xen_read_cr0(void)
991 unsigned long cr0 = this_cpu_read(xen_cr0_value);
993 if (unlikely(cr0 == 0)) {
994 cr0 = native_read_cr0();
995 this_cpu_write(xen_cr0_value, cr0);
1001 static void xen_write_cr0(unsigned long cr0)
1003 struct multicall_space mcs;
1005 this_cpu_write(xen_cr0_value, cr0);
1007 /* Only pay attention to cr0.TS; everything else is
1009 mcs = xen_mc_entry(0);
1011 MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
1013 xen_mc_issue(PARAVIRT_LAZY_CPU);
1016 static void xen_write_cr4(unsigned long cr4)
1018 cr4 &= ~(X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PCE);
1020 native_write_cr4(cr4);
1022 #ifdef CONFIG_X86_64
1023 static inline unsigned long xen_read_cr8(void)
1027 static inline void xen_write_cr8(unsigned long val)
1033 static u64 xen_read_msr_safe(unsigned int msr, int *err)
1037 if (pmu_msr_read(msr, &val, err))
1040 val = native_read_msr_safe(msr, err);
1042 case MSR_IA32_APICBASE:
1043 #ifdef CONFIG_X86_X2APIC
1044 if (!(cpuid_ecx(1) & (1 << (X86_FEATURE_X2APIC & 31))))
1046 val &= ~X2APIC_ENABLE;
1052 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
1059 #ifdef CONFIG_X86_64
1063 case MSR_FS_BASE: which = SEGBASE_FS; goto set;
1064 case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set;
1065 case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set;
1068 base = ((u64)high << 32) | low;
1069 if (HYPERVISOR_set_segment_base(which, base) != 0)
1077 case MSR_SYSCALL_MASK:
1078 case MSR_IA32_SYSENTER_CS:
1079 case MSR_IA32_SYSENTER_ESP:
1080 case MSR_IA32_SYSENTER_EIP:
1081 /* Fast syscall setup is all done in hypercalls, so
1082 these are all ignored. Stub them out here to stop
1083 Xen console noise. */
1087 if (!pmu_msr_write(msr, low, high, &ret))
1088 ret = native_write_msr_safe(msr, low, high);
1094 void xen_setup_shared_info(void)
1096 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1097 set_fixmap(FIX_PARAVIRT_BOOTMAP,
1098 xen_start_info->shared_info);
1100 HYPERVISOR_shared_info =
1101 (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
1103 HYPERVISOR_shared_info =
1104 (struct shared_info *)__va(xen_start_info->shared_info);
1107 /* In UP this is as good a place as any to set up shared info */
1108 xen_setup_vcpu_info_placement();
1111 xen_setup_mfn_list_list();
1114 /* This is called once we have the cpu_possible_mask */
1115 void xen_setup_vcpu_info_placement(void)
1119 for_each_possible_cpu(cpu)
1120 xen_vcpu_setup(cpu);
1122 /* xen_vcpu_setup managed to place the vcpu_info within the
1123 * percpu area for all cpus, so make use of it. Note that for
1124 * PVH we want to use native IRQ mechanism. */
1125 if (have_vcpu_info_placement && !xen_pvh_domain()) {
1126 pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
1127 pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct);
1128 pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
1129 pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
1130 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
1134 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
1135 unsigned long addr, unsigned len)
1137 char *start, *end, *reloc;
1140 start = end = reloc = NULL;
1142 #define SITE(op, x) \
1143 case PARAVIRT_PATCH(op.x): \
1144 if (have_vcpu_info_placement) { \
1145 start = (char *)xen_##x##_direct; \
1146 end = xen_##x##_direct_end; \
1147 reloc = xen_##x##_direct_reloc; \
1152 SITE(pv_irq_ops, irq_enable);
1153 SITE(pv_irq_ops, irq_disable);
1154 SITE(pv_irq_ops, save_fl);
1155 SITE(pv_irq_ops, restore_fl);
1159 if (start == NULL || (end-start) > len)
1162 ret = paravirt_patch_insns(insnbuf, len, start, end);
1164 /* Note: because reloc is assigned from something that
1165 appears to be an array, gcc assumes it's non-null,
1166 but doesn't know its relationship with start and
1168 if (reloc > start && reloc < end) {
1169 int reloc_off = reloc - start;
1170 long *relocp = (long *)(insnbuf + reloc_off);
1171 long delta = start - (char *)addr;
1179 ret = paravirt_patch_default(type, clobbers, insnbuf,
1187 static const struct pv_info xen_info __initconst = {
1188 .paravirt_enabled = 1,
1189 .shared_kernel_pmd = 0,
1191 #ifdef CONFIG_X86_64
1192 .extra_user_64bit_cs = FLAT_USER_CS64,
1198 static const struct pv_init_ops xen_init_ops __initconst = {
1202 static const struct pv_cpu_ops xen_cpu_ops __initconst = {
1205 .set_debugreg = xen_set_debugreg,
1206 .get_debugreg = xen_get_debugreg,
1210 .read_cr0 = xen_read_cr0,
1211 .write_cr0 = xen_write_cr0,
1213 .read_cr4 = native_read_cr4,
1214 .read_cr4_safe = native_read_cr4_safe,
1215 .write_cr4 = xen_write_cr4,
1217 #ifdef CONFIG_X86_64
1218 .read_cr8 = xen_read_cr8,
1219 .write_cr8 = xen_write_cr8,
1222 .wbinvd = native_wbinvd,
1224 .read_msr = xen_read_msr_safe,
1225 .write_msr = xen_write_msr_safe,
1227 .read_pmc = xen_read_pmc,
1230 #ifdef CONFIG_X86_64
1231 .usergs_sysret32 = xen_sysret32,
1232 .usergs_sysret64 = xen_sysret64,
1234 .irq_enable_sysexit = xen_sysexit,
1237 .load_tr_desc = paravirt_nop,
1238 .set_ldt = xen_set_ldt,
1239 .load_gdt = xen_load_gdt,
1240 .load_idt = xen_load_idt,
1241 .load_tls = xen_load_tls,
1242 #ifdef CONFIG_X86_64
1243 .load_gs_index = xen_load_gs_index,
1246 .alloc_ldt = xen_alloc_ldt,
1247 .free_ldt = xen_free_ldt,
1249 .store_idt = native_store_idt,
1250 .store_tr = xen_store_tr,
1252 .write_ldt_entry = xen_write_ldt_entry,
1253 .write_gdt_entry = xen_write_gdt_entry,
1254 .write_idt_entry = xen_write_idt_entry,
1255 .load_sp0 = xen_load_sp0,
1257 .set_iopl_mask = xen_set_iopl_mask,
1258 .io_delay = xen_io_delay,
1260 /* Xen takes care of %gs when switching to usermode for us */
1261 .swapgs = paravirt_nop,
1263 .start_context_switch = paravirt_start_context_switch,
1264 .end_context_switch = xen_end_context_switch,
1267 static const struct pv_apic_ops xen_apic_ops __initconst = {
1268 #ifdef CONFIG_X86_LOCAL_APIC
1269 .startup_ipi_hook = paravirt_nop,
1273 static void xen_reboot(int reason)
1275 struct sched_shutdown r = { .reason = reason };
1278 for_each_online_cpu(cpu)
1279 xen_pmu_finish(cpu);
1281 if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
1285 static void xen_restart(char *msg)
1287 xen_reboot(SHUTDOWN_reboot);
1290 static void xen_emergency_restart(void)
1292 xen_reboot(SHUTDOWN_reboot);
1295 static void xen_machine_halt(void)
1297 xen_reboot(SHUTDOWN_poweroff);
1300 static void xen_machine_power_off(void)
1304 xen_reboot(SHUTDOWN_poweroff);
1307 static void xen_crash_shutdown(struct pt_regs *regs)
1309 xen_reboot(SHUTDOWN_crash);
1313 xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
1315 xen_reboot(SHUTDOWN_crash);
1319 static struct notifier_block xen_panic_block = {
1320 .notifier_call= xen_panic_event,
1324 int xen_panic_handler_init(void)
1326 atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block);
1330 static const struct machine_ops xen_machine_ops __initconst = {
1331 .restart = xen_restart,
1332 .halt = xen_machine_halt,
1333 .power_off = xen_machine_power_off,
1334 .shutdown = xen_machine_halt,
1335 .crash_shutdown = xen_crash_shutdown,
1336 .emergency_restart = xen_emergency_restart,
1339 static unsigned char xen_get_nmi_reason(void)
1341 unsigned char reason = 0;
1343 /* Construct a value which looks like it came from port 0x61. */
1344 if (test_bit(_XEN_NMIREASON_io_error,
1345 &HYPERVISOR_shared_info->arch.nmi_reason))
1346 reason |= NMI_REASON_IOCHK;
1347 if (test_bit(_XEN_NMIREASON_pci_serr,
1348 &HYPERVISOR_shared_info->arch.nmi_reason))
1349 reason |= NMI_REASON_SERR;
1354 static void __init xen_boot_params_init_edd(void)
1356 #if IS_ENABLED(CONFIG_EDD)
1357 struct xen_platform_op op;
1358 struct edd_info *edd_info;
1363 edd_info = boot_params.eddbuf;
1364 mbr_signature = boot_params.edd_mbr_sig_buffer;
1366 op.cmd = XENPF_firmware_info;
1368 op.u.firmware_info.type = XEN_FW_DISK_INFO;
1369 for (nr = 0; nr < EDDMAXNR; nr++) {
1370 struct edd_info *info = edd_info + nr;
1372 op.u.firmware_info.index = nr;
1373 info->params.length = sizeof(info->params);
1374 set_xen_guest_handle(op.u.firmware_info.u.disk_info.edd_params,
1376 ret = HYPERVISOR_dom0_op(&op);
1380 #define C(x) info->x = op.u.firmware_info.u.disk_info.x
1383 C(interface_support);
1384 C(legacy_max_cylinder);
1386 C(legacy_sectors_per_track);
1389 boot_params.eddbuf_entries = nr;
1391 op.u.firmware_info.type = XEN_FW_DISK_MBR_SIGNATURE;
1392 for (nr = 0; nr < EDD_MBR_SIG_MAX; nr++) {
1393 op.u.firmware_info.index = nr;
1394 ret = HYPERVISOR_dom0_op(&op);
1397 mbr_signature[nr] = op.u.firmware_info.u.disk_mbr_signature.mbr_signature;
1399 boot_params.edd_mbr_sig_buf_entries = nr;
1404 * Set up the GDT and segment registers for -fstack-protector. Until
1405 * we do this, we have to be careful not to call any stack-protected
1406 * function, which is most of the kernel.
1408 * Note, that it is __ref because the only caller of this after init
1409 * is PVH which is not going to use xen_load_gdt_boot or other
1412 static void __ref xen_setup_gdt(int cpu)
1414 if (xen_feature(XENFEAT_auto_translated_physmap)) {
1415 #ifdef CONFIG_X86_64
1416 unsigned long dummy;
1418 load_percpu_segment(cpu); /* We need to access per-cpu area */
1419 switch_to_new_gdt(cpu); /* GDT and GS set */
1421 /* We are switching of the Xen provided GDT to our HVM mode
1422 * GDT. The new GDT has __KERNEL_CS with CS.L = 1
1423 * and we are jumping to reload it.
1425 asm volatile ("pushq %0\n"
1426 "leaq 1f(%%rip),%0\n"
1430 : "=&r" (dummy) : "0" (__KERNEL_CS));
1433 * While not needed, we also set the %es, %ds, and %fs
1434 * to zero. We don't care about %ss as it is NULL.
1435 * Strictly speaking this is not needed as Xen zeros those
1436 * out (and also MSR_FS_BASE, MSR_GS_BASE, MSR_KERNEL_GS_BASE)
1438 * Linux zeros them in cpu_init() and in secondary_startup_64
1445 /* PVH: TODO Implement. */
1448 return; /* PVH does not need any PV GDT ops. */
1450 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
1451 pv_cpu_ops.load_gdt = xen_load_gdt_boot;
1453 setup_stack_canary_segment(0);
1454 switch_to_new_gdt(0);
1456 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry;
1457 pv_cpu_ops.load_gdt = xen_load_gdt;
1460 #ifdef CONFIG_XEN_PVH
1462 * A PV guest starts with default flags that are not set for PVH, set them
1465 static void xen_pvh_set_cr_flags(int cpu)
1468 /* Some of these are setup in 'secondary_startup_64'. The others:
1469 * X86_CR0_TS, X86_CR0_PE, X86_CR0_ET are set by Xen for HVM guests
1470 * (which PVH shared codepaths), while X86_CR0_PG is for PVH. */
1471 write_cr0(read_cr0() | X86_CR0_MP | X86_CR0_NE | X86_CR0_WP | X86_CR0_AM);
1476 * For BSP, PSE PGE are set in probe_page_size_mask(), for APs
1477 * set them here. For all, OSFXSR OSXMMEXCPT are set in fpu__init_cpu().
1480 cr4_set_bits_and_update_boot(X86_CR4_PSE);
1483 cr4_set_bits_and_update_boot(X86_CR4_PGE);
1487 * Note, that it is ref - because the only caller of this after init
1488 * is PVH which is not going to use xen_load_gdt_boot or other
1491 void __ref xen_pvh_secondary_vcpu_init(int cpu)
1494 xen_pvh_set_cr_flags(cpu);
1497 static void __init xen_pvh_early_guest_init(void)
1499 if (!xen_feature(XENFEAT_auto_translated_physmap))
1502 if (!xen_feature(XENFEAT_hvm_callback_vector))
1505 xen_have_vector_callback = 1;
1507 xen_pvh_early_cpu_init(0, false);
1508 xen_pvh_set_cr_flags(0);
1510 #ifdef CONFIG_X86_32
1511 BUG(); /* PVH: Implement proper support. */
1514 #endif /* CONFIG_XEN_PVH */
1516 /* First C function to be called on Xen boot */
1517 asmlinkage __visible void __init xen_start_kernel(void)
1519 struct physdev_set_iopl set_iopl;
1520 unsigned long initrd_start = 0;
1524 if (!xen_start_info)
1527 xen_domain_type = XEN_PV_DOMAIN;
1529 xen_setup_features();
1530 #ifdef CONFIG_XEN_PVH
1531 xen_pvh_early_guest_init();
1533 xen_setup_machphys_mapping();
1535 /* Install Xen paravirt ops */
1537 pv_init_ops = xen_init_ops;
1538 pv_apic_ops = xen_apic_ops;
1539 if (!xen_pvh_domain()) {
1540 pv_cpu_ops = xen_cpu_ops;
1542 x86_platform.get_nmi_reason = xen_get_nmi_reason;
1545 if (xen_feature(XENFEAT_auto_translated_physmap))
1546 x86_init.resources.memory_setup = xen_auto_xlated_memory_setup;
1548 x86_init.resources.memory_setup = xen_memory_setup;
1549 x86_init.oem.arch_setup = xen_arch_setup;
1550 x86_init.oem.banner = xen_banner;
1552 xen_init_time_ops();
1555 * Set up some pagetable state before starting to set any ptes.
1560 /* Prevent unwanted bits from being set in PTEs. */
1561 __supported_pte_mask &= ~_PAGE_GLOBAL;
1564 * Prevent page tables from being allocated in highmem, even
1565 * if CONFIG_HIGHPTE is enabled.
1567 __userpte_alloc_gfp &= ~__GFP_HIGHMEM;
1569 /* Work out if we support NX */
1573 xen_build_dynamic_phys_to_machine();
1576 * Set up kernel GDT and segment registers, mainly so that
1577 * -fstack-protector code can be executed.
1582 xen_init_cpuid_mask();
1584 #ifdef CONFIG_X86_LOCAL_APIC
1586 * set up the basic apic ops.
1591 if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
1592 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
1593 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
1596 machine_ops = xen_machine_ops;
1599 * The only reliable way to retain the initial address of the
1600 * percpu gdt_page is to remember it here, so we can go and
1601 * mark it RW later, when the initial percpu area is freed.
1603 xen_initial_gdt = &per_cpu(gdt_page, 0);
1607 #ifdef CONFIG_ACPI_NUMA
1609 * The pages we from Xen are not related to machine pages, so
1610 * any NUMA information the kernel tries to get from ACPI will
1611 * be meaningless. Prevent it from trying.
1615 /* Don't do the full vcpu_info placement stuff until we have a
1616 possible map and a non-dummy shared_info. */
1617 per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1619 local_irq_disable();
1620 early_boot_irqs_disabled = true;
1622 xen_raw_console_write("mapping kernel into physical memory\n");
1623 xen_setup_kernel_pagetable((pgd_t *)xen_start_info->pt_base,
1624 xen_start_info->nr_pages);
1625 xen_reserve_special_pages();
1628 * Modify the cache mode translation tables to match Xen's PAT
1631 rdmsrl(MSR_IA32_CR_PAT, pat);
1632 pat_init_cache_modes(pat);
1634 /* keep using Xen gdt for now; no urgent need to change it */
1636 #ifdef CONFIG_X86_32
1637 pv_info.kernel_rpl = 1;
1638 if (xen_feature(XENFEAT_supervisor_mode_kernel))
1639 pv_info.kernel_rpl = 0;
1641 pv_info.kernel_rpl = 0;
1643 /* set the limit of our address space */
1646 /* PVH: runs at default kernel iopl of 0 */
1647 if (!xen_pvh_domain()) {
1649 * We used to do this in xen_arch_setup, but that is too late
1650 * on AMD were early_cpu_init (run before ->arch_setup()) calls
1651 * early_amd_init which pokes 0xcf8 port.
1654 rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
1656 xen_raw_printk("physdev_op failed %d\n", rc);
1659 #ifdef CONFIG_X86_32
1660 /* set up basic CPUID stuff */
1661 cpu_detect(&new_cpu_data);
1662 set_cpu_cap(&new_cpu_data, X86_FEATURE_FPU);
1663 new_cpu_data.wp_works_ok = 1;
1664 new_cpu_data.x86_capability[0] = cpuid_edx(1);
1667 if (xen_start_info->mod_start) {
1668 if (xen_start_info->flags & SIF_MOD_START_PFN)
1669 initrd_start = PFN_PHYS(xen_start_info->mod_start);
1671 initrd_start = __pa(xen_start_info->mod_start);
1674 /* Poke various useful things into boot_params */
1675 boot_params.hdr.type_of_loader = (9 << 4) | 0;
1676 boot_params.hdr.ramdisk_image = initrd_start;
1677 boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
1678 boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
1680 if (!xen_initial_domain()) {
1681 add_preferred_console("xenboot", 0, NULL);
1682 add_preferred_console("tty", 0, NULL);
1683 add_preferred_console("hvc", 0, NULL);
1685 x86_init.pci.arch_init = pci_xen_init;
1687 const struct dom0_vga_console_info *info =
1688 (void *)((char *)xen_start_info +
1689 xen_start_info->console.dom0.info_off);
1690 struct xen_platform_op op = {
1691 .cmd = XENPF_firmware_info,
1692 .interface_version = XENPF_INTERFACE_VERSION,
1693 .u.firmware_info.type = XEN_FW_KBD_SHIFT_FLAGS,
1696 xen_init_vga(info, xen_start_info->console.dom0.info_size);
1697 xen_start_info->console.domU.mfn = 0;
1698 xen_start_info->console.domU.evtchn = 0;
1700 if (HYPERVISOR_dom0_op(&op) == 0)
1701 boot_params.kbd_status = op.u.firmware_info.u.kbd_shift_flags;
1703 /* Make sure ACS will be enabled */
1706 xen_acpi_sleep_register();
1708 /* Avoid searching for BIOS MP tables */
1709 x86_init.mpparse.find_smp_config = x86_init_noop;
1710 x86_init.mpparse.get_smp_config = x86_init_uint_noop;
1712 xen_boot_params_init_edd();
1715 /* PCI BIOS service won't work from a PV guest. */
1716 pci_probe &= ~PCI_PROBE_BIOS;
1718 xen_raw_console_write("about to get started...\n");
1720 xen_setup_runstate_info(0);
1724 /* Start the world */
1725 #ifdef CONFIG_X86_32
1726 i386_start_kernel();
1728 cr4_init_shadow(); /* 32b kernel does this in i386_start_kernel() */
1729 x86_64_start_reservations((char *)__pa_symbol(&boot_params));
1733 void __ref xen_hvm_init_shared_info(void)
1736 struct xen_add_to_physmap xatp;
1737 static struct shared_info *shared_info_page = 0;
1739 if (!shared_info_page)
1740 shared_info_page = (struct shared_info *)
1741 extend_brk(PAGE_SIZE, PAGE_SIZE);
1742 xatp.domid = DOMID_SELF;
1744 xatp.space = XENMAPSPACE_shared_info;
1745 xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
1746 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
1749 HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
1751 /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
1752 * page, we use it in the event channel upcall and in some pvclock
1753 * related functions. We don't need the vcpu_info placement
1754 * optimizations because we don't use any pv_mmu or pv_irq op on
1756 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
1757 * online but xen_hvm_init_shared_info is run at resume time too and
1758 * in that case multiple vcpus might be online. */
1759 for_each_online_cpu(cpu) {
1760 /* Leave it to be NULL. */
1761 if (cpu >= MAX_VIRT_CPUS)
1763 per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
1767 #ifdef CONFIG_XEN_PVHVM
1768 static void __init init_hvm_pv_info(void)
1771 uint32_t eax, ebx, ecx, edx, pages, msr, base;
1774 base = xen_cpuid_base();
1775 cpuid(base + 1, &eax, &ebx, &ecx, &edx);
1778 minor = eax & 0xffff;
1779 printk(KERN_INFO "Xen version %d.%d.\n", major, minor);
1781 cpuid(base + 2, &pages, &msr, &ecx, &edx);
1783 pfn = __pa(hypercall_page);
1784 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
1786 xen_setup_features();
1788 pv_info.name = "Xen HVM";
1790 xen_domain_type = XEN_HVM_DOMAIN;
1793 static int xen_hvm_cpu_notify(struct notifier_block *self, unsigned long action,
1796 int cpu = (long)hcpu;
1798 case CPU_UP_PREPARE:
1799 xen_vcpu_setup(cpu);
1800 if (xen_have_vector_callback) {
1801 if (xen_feature(XENFEAT_hvm_safe_pvclock))
1802 xen_setup_timer(cpu);
1811 static struct notifier_block xen_hvm_cpu_notifier = {
1812 .notifier_call = xen_hvm_cpu_notify,
1815 #ifdef CONFIG_KEXEC_CORE
1816 static void xen_hvm_shutdown(void)
1818 native_machine_shutdown();
1819 if (kexec_in_progress)
1820 xen_reboot(SHUTDOWN_soft_reset);
1823 static void xen_hvm_crash_shutdown(struct pt_regs *regs)
1825 native_machine_crash_shutdown(regs);
1826 xen_reboot(SHUTDOWN_soft_reset);
1830 static void __init xen_hvm_guest_init(void)
1832 if (xen_pv_domain())
1837 xen_hvm_init_shared_info();
1839 xen_panic_handler_init();
1841 if (xen_feature(XENFEAT_hvm_callback_vector))
1842 xen_have_vector_callback = 1;
1844 register_cpu_notifier(&xen_hvm_cpu_notifier);
1845 xen_unplug_emulated_devices();
1846 x86_init.irqs.intr_init = xen_init_IRQ;
1847 xen_hvm_init_time_ops();
1848 xen_hvm_init_mmu_ops();
1849 #ifdef CONFIG_KEXEC_CORE
1850 machine_ops.shutdown = xen_hvm_shutdown;
1851 machine_ops.crash_shutdown = xen_hvm_crash_shutdown;
1856 static bool xen_nopv = false;
1857 static __init int xen_parse_nopv(char *arg)
1862 early_param("xen_nopv", xen_parse_nopv);
1864 static uint32_t __init xen_platform(void)
1869 return xen_cpuid_base();
1872 bool xen_hvm_need_lapic(void)
1876 if (xen_pv_domain())
1878 if (!xen_hvm_domain())
1880 if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
1884 EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
1886 static void xen_set_cpu_features(struct cpuinfo_x86 *c)
1888 if (xen_pv_domain())
1889 clear_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
1892 const struct hypervisor_x86 x86_hyper_xen = {
1894 .detect = xen_platform,
1895 #ifdef CONFIG_XEN_PVHVM
1896 .init_platform = xen_hvm_guest_init,
1898 .x2apic_available = xen_x2apic_para_available,
1899 .set_cpu_features = xen_set_cpu_features,
1901 EXPORT_SYMBOL(x86_hyper_xen);