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/kernel.h>
15 #include <linux/init.h>
16 #include <linux/smp.h>
17 #include <linux/preempt.h>
18 #include <linux/hardirq.h>
19 #include <linux/percpu.h>
20 #include <linux/delay.h>
21 #include <linux/start_kernel.h>
22 #include <linux/sched.h>
23 #include <linux/kprobes.h>
24 #include <linux/bootmem.h>
25 #include <linux/module.h>
27 #include <linux/page-flags.h>
28 #include <linux/highmem.h>
29 #include <linux/console.h>
30 #include <linux/pci.h>
33 #include <xen/interface/xen.h>
34 #include <xen/interface/version.h>
35 #include <xen/interface/physdev.h>
36 #include <xen/interface/vcpu.h>
37 #include <xen/features.h>
39 #include <xen/hvc-console.h>
41 #include <asm/paravirt.h>
44 #include <asm/xen/hypercall.h>
45 #include <asm/xen/hypervisor.h>
46 #include <asm/fixmap.h>
47 #include <asm/processor.h>
48 #include <asm/proto.h>
49 #include <asm/msr-index.h>
50 #include <asm/traps.h>
51 #include <asm/setup.h>
53 #include <asm/pgtable.h>
54 #include <asm/tlbflush.h>
55 #include <asm/reboot.h>
56 #include <asm/stackprotector.h>
60 #include "multicalls.h"
62 EXPORT_SYMBOL_GPL(hypercall_page);
64 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
65 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
67 enum xen_domain_type xen_domain_type = XEN_NATIVE;
68 EXPORT_SYMBOL_GPL(xen_domain_type);
70 struct start_info *xen_start_info;
71 EXPORT_SYMBOL_GPL(xen_start_info);
73 struct shared_info xen_dummy_shared_info;
75 void *xen_initial_gdt;
78 * Point at some empty memory to start with. We map the real shared_info
79 * page as soon as fixmap is up and running.
81 struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
84 * Flag to determine whether vcpu info placement is available on all
85 * VCPUs. We assume it is to start with, and then set it to zero on
86 * the first failure. This is because it can succeed on some VCPUs
87 * and not others, since it can involve hypervisor memory allocation,
88 * or because the guest failed to guarantee all the appropriate
89 * constraints on all VCPUs (ie buffer can't cross a page boundary).
91 * Note that any particular CPU may be using a placed vcpu structure,
92 * but we can only optimise if the all are.
94 * 0: not available, 1: available
96 static int have_vcpu_info_placement = 1;
98 static void xen_vcpu_setup(int cpu)
100 struct vcpu_register_vcpu_info info;
102 struct vcpu_info *vcpup;
104 BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
105 per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
107 if (!have_vcpu_info_placement)
108 return; /* already tested, not available */
110 vcpup = &per_cpu(xen_vcpu_info, cpu);
112 info.mfn = arbitrary_virt_to_mfn(vcpup);
113 info.offset = offset_in_page(vcpup);
115 printk(KERN_DEBUG "trying to map vcpu_info %d at %p, mfn %llx, offset %d\n",
116 cpu, vcpup, info.mfn, info.offset);
118 /* Check to see if the hypervisor will put the vcpu_info
119 structure where we want it, which allows direct access via
120 a percpu-variable. */
121 err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
124 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
125 have_vcpu_info_placement = 0;
127 /* This cpu is using the registered vcpu info, even if
128 later ones fail to. */
129 per_cpu(xen_vcpu, cpu) = vcpup;
131 printk(KERN_DEBUG "cpu %d using vcpu_info at %p\n",
137 * On restore, set the vcpu placement up again.
138 * If it fails, then we're in a bad state, since
139 * we can't back out from using it...
141 void xen_vcpu_restore(void)
145 for_each_online_cpu(cpu) {
146 bool other_cpu = (cpu != smp_processor_id());
149 HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL))
152 xen_setup_runstate_info(cpu);
154 if (have_vcpu_info_placement)
158 HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
163 static void __init xen_banner(void)
165 unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
166 struct xen_extraversion extra;
167 HYPERVISOR_xen_version(XENVER_extraversion, &extra);
169 printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
171 printk(KERN_INFO "Xen version: %d.%d%s%s\n",
172 version >> 16, version & 0xffff, extra.extraversion,
173 xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
176 static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
177 static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
179 static void xen_cpuid(unsigned int *ax, unsigned int *bx,
180 unsigned int *cx, unsigned int *dx)
182 unsigned maskebx = ~0;
183 unsigned maskecx = ~0;
184 unsigned maskedx = ~0;
187 * Mask out inconvenient features, to try and disable as many
188 * unsupported kernel subsystems as possible.
192 maskecx = cpuid_leaf1_ecx_mask;
193 maskedx = cpuid_leaf1_edx_mask;
197 /* Suppress extended topology stuff */
202 asm(XEN_EMULATE_PREFIX "cpuid"
207 : "0" (*ax), "2" (*cx));
214 static __init void xen_init_cpuid_mask(void)
216 unsigned int ax, bx, cx, dx;
218 cpuid_leaf1_edx_mask =
219 ~((1 << X86_FEATURE_MCE) | /* disable MCE */
220 (1 << X86_FEATURE_MCA) | /* disable MCA */
221 (1 << X86_FEATURE_ACC)); /* thermal monitoring */
223 if (!xen_initial_domain())
224 cpuid_leaf1_edx_mask &=
225 ~((1 << X86_FEATURE_APIC) | /* disable local APIC */
226 (1 << X86_FEATURE_ACPI)); /* disable ACPI */
230 xen_cpuid(&ax, &bx, &cx, &dx);
232 /* cpuid claims we support xsave; try enabling it to see what happens */
233 if (cx & (1 << (X86_FEATURE_XSAVE % 32))) {
236 set_in_cr4(X86_CR4_OSXSAVE);
240 if ((cr4 & X86_CR4_OSXSAVE) == 0)
241 cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_XSAVE % 32));
243 clear_in_cr4(X86_CR4_OSXSAVE);
247 static void xen_set_debugreg(int reg, unsigned long val)
249 HYPERVISOR_set_debugreg(reg, val);
252 static unsigned long xen_get_debugreg(int reg)
254 return HYPERVISOR_get_debugreg(reg);
257 static void xen_end_context_switch(struct task_struct *next)
260 paravirt_end_context_switch(next);
263 static unsigned long xen_store_tr(void)
269 * Set the page permissions for a particular virtual address. If the
270 * address is a vmalloc mapping (or other non-linear mapping), then
271 * find the linear mapping of the page and also set its protections to
274 static void set_aliased_prot(void *v, pgprot_t prot)
282 ptep = lookup_address((unsigned long)v, &level);
283 BUG_ON(ptep == NULL);
285 pfn = pte_pfn(*ptep);
286 page = pfn_to_page(pfn);
288 pte = pfn_pte(pfn, prot);
290 if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
293 if (!PageHighMem(page)) {
294 void *av = __va(PFN_PHYS(pfn));
297 if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
303 static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
305 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
308 for(i = 0; i < entries; i += entries_per_page)
309 set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
312 static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
314 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
317 for(i = 0; i < entries; i += entries_per_page)
318 set_aliased_prot(ldt + i, PAGE_KERNEL);
321 static void xen_set_ldt(const void *addr, unsigned entries)
323 struct mmuext_op *op;
324 struct multicall_space mcs = xen_mc_entry(sizeof(*op));
327 op->cmd = MMUEXT_SET_LDT;
328 op->arg1.linear_addr = (unsigned long)addr;
329 op->arg2.nr_ents = entries;
331 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
333 xen_mc_issue(PARAVIRT_LAZY_CPU);
336 static void xen_load_gdt(const struct desc_ptr *dtr)
338 unsigned long va = dtr->address;
339 unsigned int size = dtr->size + 1;
340 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
341 unsigned long frames[pages];
345 * A GDT can be up to 64k in size, which corresponds to 8192
346 * 8-byte entries, or 16 4k pages..
349 BUG_ON(size > 65536);
350 BUG_ON(va & ~PAGE_MASK);
352 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
355 unsigned long pfn, mfn;
359 * The GDT is per-cpu and is in the percpu data area.
360 * That can be virtually mapped, so we need to do a
361 * page-walk to get the underlying MFN for the
362 * hypercall. The page can also be in the kernel's
363 * linear range, so we need to RO that mapping too.
365 ptep = lookup_address(va, &level);
366 BUG_ON(ptep == NULL);
368 pfn = pte_pfn(*ptep);
369 mfn = pfn_to_mfn(pfn);
370 virt = __va(PFN_PHYS(pfn));
374 make_lowmem_page_readonly((void *)va);
375 make_lowmem_page_readonly(virt);
378 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
383 * load_gdt for early boot, when the gdt is only mapped once
385 static __init void xen_load_gdt_boot(const struct desc_ptr *dtr)
387 unsigned long va = dtr->address;
388 unsigned int size = dtr->size + 1;
389 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
390 unsigned long frames[pages];
394 * A GDT can be up to 64k in size, which corresponds to 8192
395 * 8-byte entries, or 16 4k pages..
398 BUG_ON(size > 65536);
399 BUG_ON(va & ~PAGE_MASK);
401 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
403 unsigned long pfn, mfn;
405 pfn = virt_to_pfn(va);
406 mfn = pfn_to_mfn(pfn);
408 pte = pfn_pte(pfn, PAGE_KERNEL_RO);
410 if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0))
416 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
420 static void load_TLS_descriptor(struct thread_struct *t,
421 unsigned int cpu, unsigned int i)
423 struct desc_struct *gdt = get_cpu_gdt_table(cpu);
424 xmaddr_t maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
425 struct multicall_space mc = __xen_mc_entry(0);
427 MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
430 static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
433 * XXX sleazy hack: If we're being called in a lazy-cpu zone
434 * and lazy gs handling is enabled, it means we're in a
435 * context switch, and %gs has just been saved. This means we
436 * can zero it out to prevent faults on exit from the
437 * hypervisor if the next process has no %gs. Either way, it
438 * has been saved, and the new value will get loaded properly.
439 * This will go away as soon as Xen has been modified to not
440 * save/restore %gs for normal hypercalls.
442 * On x86_64, this hack is not used for %gs, because gs points
443 * to KERNEL_GS_BASE (and uses it for PDA references), so we
444 * must not zero %gs on x86_64
446 * For x86_64, we need to zero %fs, otherwise we may get an
447 * exception between the new %fs descriptor being loaded and
448 * %fs being effectively cleared at __switch_to().
450 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
460 load_TLS_descriptor(t, cpu, 0);
461 load_TLS_descriptor(t, cpu, 1);
462 load_TLS_descriptor(t, cpu, 2);
464 xen_mc_issue(PARAVIRT_LAZY_CPU);
468 static void xen_load_gs_index(unsigned int idx)
470 if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
475 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
478 xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
479 u64 entry = *(u64 *)ptr;
484 if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
490 static int cvt_gate_to_trap(int vector, const gate_desc *val,
491 struct trap_info *info)
495 if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT)
498 info->vector = vector;
500 addr = gate_offset(*val);
503 * Look for known traps using IST, and substitute them
504 * appropriately. The debugger ones are the only ones we care
505 * about. Xen will handle faults like double_fault and
506 * machine_check, so we should never see them. Warn if
507 * there's an unexpected IST-using fault handler.
509 if (addr == (unsigned long)debug)
510 addr = (unsigned long)xen_debug;
511 else if (addr == (unsigned long)int3)
512 addr = (unsigned long)xen_int3;
513 else if (addr == (unsigned long)stack_segment)
514 addr = (unsigned long)xen_stack_segment;
515 else if (addr == (unsigned long)double_fault ||
516 addr == (unsigned long)nmi) {
517 /* Don't need to handle these */
519 #ifdef CONFIG_X86_MCE
520 } else if (addr == (unsigned long)machine_check) {
524 /* Some other trap using IST? */
525 if (WARN_ON(val->ist != 0))
528 #endif /* CONFIG_X86_64 */
529 info->address = addr;
531 info->cs = gate_segment(*val);
532 info->flags = val->dpl;
533 /* interrupt gates clear IF */
534 if (val->type == GATE_INTERRUPT)
535 info->flags |= 1 << 2;
540 /* Locations of each CPU's IDT */
541 static DEFINE_PER_CPU(struct desc_ptr, idt_desc);
543 /* Set an IDT entry. If the entry is part of the current IDT, then
545 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
547 unsigned long p = (unsigned long)&dt[entrynum];
548 unsigned long start, end;
552 start = __get_cpu_var(idt_desc).address;
553 end = start + __get_cpu_var(idt_desc).size + 1;
557 native_write_idt_entry(dt, entrynum, g);
559 if (p >= start && (p + 8) <= end) {
560 struct trap_info info[2];
564 if (cvt_gate_to_trap(entrynum, g, &info[0]))
565 if (HYPERVISOR_set_trap_table(info))
572 static void xen_convert_trap_info(const struct desc_ptr *desc,
573 struct trap_info *traps)
575 unsigned in, out, count;
577 count = (desc->size+1) / sizeof(gate_desc);
580 for (in = out = 0; in < count; in++) {
581 gate_desc *entry = (gate_desc*)(desc->address) + in;
583 if (cvt_gate_to_trap(in, entry, &traps[out]))
586 traps[out].address = 0;
589 void xen_copy_trap_info(struct trap_info *traps)
591 const struct desc_ptr *desc = &__get_cpu_var(idt_desc);
593 xen_convert_trap_info(desc, traps);
596 /* Load a new IDT into Xen. In principle this can be per-CPU, so we
597 hold a spinlock to protect the static traps[] array (static because
598 it avoids allocation, and saves stack space). */
599 static void xen_load_idt(const struct desc_ptr *desc)
601 static DEFINE_SPINLOCK(lock);
602 static struct trap_info traps[257];
606 __get_cpu_var(idt_desc) = *desc;
608 xen_convert_trap_info(desc, traps);
611 if (HYPERVISOR_set_trap_table(traps))
617 /* Write a GDT descriptor entry. Ignore LDT descriptors, since
618 they're handled differently. */
619 static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
620 const void *desc, int type)
631 xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]);
634 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
644 * Version of write_gdt_entry for use at early boot-time needed to
645 * update an entry as simply as possible.
647 static __init void xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
648 const void *desc, int type)
657 xmaddr_t maddr = virt_to_machine(&dt[entry]);
659 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
660 dt[entry] = *(struct desc_struct *)desc;
666 static void xen_load_sp0(struct tss_struct *tss,
667 struct thread_struct *thread)
669 struct multicall_space mcs = xen_mc_entry(0);
670 MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
671 xen_mc_issue(PARAVIRT_LAZY_CPU);
674 static void xen_set_iopl_mask(unsigned mask)
676 struct physdev_set_iopl set_iopl;
678 /* Force the change at ring 0. */
679 set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
680 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
683 static void xen_io_delay(void)
687 #ifdef CONFIG_X86_LOCAL_APIC
688 static u32 xen_apic_read(u32 reg)
693 static void xen_apic_write(u32 reg, u32 val)
695 /* Warn to see if there's any stray references */
699 static u64 xen_apic_icr_read(void)
704 static void xen_apic_icr_write(u32 low, u32 id)
706 /* Warn to see if there's any stray references */
710 static void xen_apic_wait_icr_idle(void)
715 static u32 xen_safe_apic_wait_icr_idle(void)
720 static void set_xen_basic_apic_ops(void)
722 apic->read = xen_apic_read;
723 apic->write = xen_apic_write;
724 apic->icr_read = xen_apic_icr_read;
725 apic->icr_write = xen_apic_icr_write;
726 apic->wait_icr_idle = xen_apic_wait_icr_idle;
727 apic->safe_wait_icr_idle = xen_safe_apic_wait_icr_idle;
733 static void xen_clts(void)
735 struct multicall_space mcs;
737 mcs = xen_mc_entry(0);
739 MULTI_fpu_taskswitch(mcs.mc, 0);
741 xen_mc_issue(PARAVIRT_LAZY_CPU);
744 static DEFINE_PER_CPU(unsigned long, xen_cr0_value);
746 static unsigned long xen_read_cr0(void)
748 unsigned long cr0 = percpu_read(xen_cr0_value);
750 if (unlikely(cr0 == 0)) {
751 cr0 = native_read_cr0();
752 percpu_write(xen_cr0_value, cr0);
758 static void xen_write_cr0(unsigned long cr0)
760 struct multicall_space mcs;
762 percpu_write(xen_cr0_value, cr0);
764 /* Only pay attention to cr0.TS; everything else is
766 mcs = xen_mc_entry(0);
768 MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
770 xen_mc_issue(PARAVIRT_LAZY_CPU);
773 static void xen_write_cr4(unsigned long cr4)
778 native_write_cr4(cr4);
781 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
792 case MSR_FS_BASE: which = SEGBASE_FS; goto set;
793 case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set;
794 case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set;
797 base = ((u64)high << 32) | low;
798 if (HYPERVISOR_set_segment_base(which, base) != 0)
806 case MSR_SYSCALL_MASK:
807 case MSR_IA32_SYSENTER_CS:
808 case MSR_IA32_SYSENTER_ESP:
809 case MSR_IA32_SYSENTER_EIP:
810 /* Fast syscall setup is all done in hypercalls, so
811 these are all ignored. Stub them out here to stop
812 Xen console noise. */
816 ret = native_write_msr_safe(msr, low, high);
822 void xen_setup_shared_info(void)
824 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
825 set_fixmap(FIX_PARAVIRT_BOOTMAP,
826 xen_start_info->shared_info);
828 HYPERVISOR_shared_info =
829 (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
831 HYPERVISOR_shared_info =
832 (struct shared_info *)__va(xen_start_info->shared_info);
835 /* In UP this is as good a place as any to set up shared info */
836 xen_setup_vcpu_info_placement();
839 xen_setup_mfn_list_list();
842 /* This is called once we have the cpu_possible_map */
843 void xen_setup_vcpu_info_placement(void)
847 for_each_possible_cpu(cpu)
850 /* xen_vcpu_setup managed to place the vcpu_info within the
851 percpu area for all cpus, so make use of it */
852 if (have_vcpu_info_placement) {
853 printk(KERN_INFO "Xen: using vcpu_info placement\n");
855 pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
856 pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct);
857 pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
858 pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
859 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
863 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
864 unsigned long addr, unsigned len)
866 char *start, *end, *reloc;
869 start = end = reloc = NULL;
871 #define SITE(op, x) \
872 case PARAVIRT_PATCH(op.x): \
873 if (have_vcpu_info_placement) { \
874 start = (char *)xen_##x##_direct; \
875 end = xen_##x##_direct_end; \
876 reloc = xen_##x##_direct_reloc; \
881 SITE(pv_irq_ops, irq_enable);
882 SITE(pv_irq_ops, irq_disable);
883 SITE(pv_irq_ops, save_fl);
884 SITE(pv_irq_ops, restore_fl);
888 if (start == NULL || (end-start) > len)
891 ret = paravirt_patch_insns(insnbuf, len, start, end);
893 /* Note: because reloc is assigned from something that
894 appears to be an array, gcc assumes it's non-null,
895 but doesn't know its relationship with start and
897 if (reloc > start && reloc < end) {
898 int reloc_off = reloc - start;
899 long *relocp = (long *)(insnbuf + reloc_off);
900 long delta = start - (char *)addr;
908 ret = paravirt_patch_default(type, clobbers, insnbuf,
916 static const struct pv_info xen_info __initdata = {
917 .paravirt_enabled = 1,
918 .shared_kernel_pmd = 0,
923 static const struct pv_init_ops xen_init_ops __initdata = {
927 static const struct pv_time_ops xen_time_ops __initdata = {
928 .sched_clock = xen_sched_clock,
931 static const struct pv_cpu_ops xen_cpu_ops __initdata = {
934 .set_debugreg = xen_set_debugreg,
935 .get_debugreg = xen_get_debugreg,
939 .read_cr0 = xen_read_cr0,
940 .write_cr0 = xen_write_cr0,
942 .read_cr4 = native_read_cr4,
943 .read_cr4_safe = native_read_cr4_safe,
944 .write_cr4 = xen_write_cr4,
946 .wbinvd = native_wbinvd,
948 .read_msr = native_read_msr_safe,
949 .write_msr = xen_write_msr_safe,
950 .read_tsc = native_read_tsc,
951 .read_pmc = native_read_pmc,
954 .irq_enable_sysexit = xen_sysexit,
956 .usergs_sysret32 = xen_sysret32,
957 .usergs_sysret64 = xen_sysret64,
960 .load_tr_desc = paravirt_nop,
961 .set_ldt = xen_set_ldt,
962 .load_gdt = xen_load_gdt,
963 .load_idt = xen_load_idt,
964 .load_tls = xen_load_tls,
966 .load_gs_index = xen_load_gs_index,
969 .alloc_ldt = xen_alloc_ldt,
970 .free_ldt = xen_free_ldt,
972 .store_gdt = native_store_gdt,
973 .store_idt = native_store_idt,
974 .store_tr = xen_store_tr,
976 .write_ldt_entry = xen_write_ldt_entry,
977 .write_gdt_entry = xen_write_gdt_entry,
978 .write_idt_entry = xen_write_idt_entry,
979 .load_sp0 = xen_load_sp0,
981 .set_iopl_mask = xen_set_iopl_mask,
982 .io_delay = xen_io_delay,
984 /* Xen takes care of %gs when switching to usermode for us */
985 .swapgs = paravirt_nop,
987 .start_context_switch = paravirt_start_context_switch,
988 .end_context_switch = xen_end_context_switch,
991 static const struct pv_apic_ops xen_apic_ops __initdata = {
992 #ifdef CONFIG_X86_LOCAL_APIC
993 .startup_ipi_hook = paravirt_nop,
997 static void xen_reboot(int reason)
999 struct sched_shutdown r = { .reason = reason };
1005 if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
1009 static void xen_restart(char *msg)
1011 xen_reboot(SHUTDOWN_reboot);
1014 static void xen_emergency_restart(void)
1016 xen_reboot(SHUTDOWN_reboot);
1019 static void xen_machine_halt(void)
1021 xen_reboot(SHUTDOWN_poweroff);
1024 static void xen_crash_shutdown(struct pt_regs *regs)
1026 xen_reboot(SHUTDOWN_crash);
1029 static const struct machine_ops __initdata xen_machine_ops = {
1030 .restart = xen_restart,
1031 .halt = xen_machine_halt,
1032 .power_off = xen_machine_halt,
1033 .shutdown = xen_machine_halt,
1034 .crash_shutdown = xen_crash_shutdown,
1035 .emergency_restart = xen_emergency_restart,
1039 * Set up the GDT and segment registers for -fstack-protector. Until
1040 * we do this, we have to be careful not to call any stack-protected
1041 * function, which is most of the kernel.
1043 static void __init xen_setup_stackprotector(void)
1045 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
1046 pv_cpu_ops.load_gdt = xen_load_gdt_boot;
1048 setup_stack_canary_segment(0);
1049 switch_to_new_gdt(0);
1051 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry;
1052 pv_cpu_ops.load_gdt = xen_load_gdt;
1055 /* First C function to be called on Xen boot */
1056 asmlinkage void __init xen_start_kernel(void)
1060 if (!xen_start_info)
1063 xen_domain_type = XEN_PV_DOMAIN;
1065 /* Install Xen paravirt ops */
1067 pv_init_ops = xen_init_ops;
1068 pv_time_ops = xen_time_ops;
1069 pv_cpu_ops = xen_cpu_ops;
1070 pv_apic_ops = xen_apic_ops;
1072 x86_init.resources.memory_setup = xen_memory_setup;
1073 x86_init.oem.arch_setup = xen_arch_setup;
1074 x86_init.oem.banner = xen_banner;
1076 x86_init.timers.timer_init = xen_time_init;
1077 x86_init.timers.setup_percpu_clockev = x86_init_noop;
1078 x86_cpuinit.setup_percpu_clockev = x86_init_noop;
1080 x86_platform.calibrate_tsc = xen_tsc_khz;
1081 x86_platform.get_wallclock = xen_get_wallclock;
1082 x86_platform.set_wallclock = xen_set_wallclock;
1085 * Set up some pagetable state before starting to set any ptes.
1090 /* Prevent unwanted bits from being set in PTEs. */
1091 __supported_pte_mask &= ~_PAGE_GLOBAL;
1092 if (!xen_initial_domain())
1093 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
1095 __supported_pte_mask |= _PAGE_IOMAP;
1097 /* Work out if we support NX */
1100 xen_setup_features();
1103 if (!xen_feature(XENFEAT_auto_translated_physmap))
1104 xen_build_dynamic_phys_to_machine();
1107 * Set up kernel GDT and segment registers, mainly so that
1108 * -fstack-protector code can be executed.
1110 xen_setup_stackprotector();
1113 xen_init_cpuid_mask();
1115 #ifdef CONFIG_X86_LOCAL_APIC
1117 * set up the basic apic ops.
1119 set_xen_basic_apic_ops();
1122 if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
1123 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
1124 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
1127 machine_ops = xen_machine_ops;
1130 * The only reliable way to retain the initial address of the
1131 * percpu gdt_page is to remember it here, so we can go and
1132 * mark it RW later, when the initial percpu area is freed.
1134 xen_initial_gdt = &per_cpu(gdt_page, 0);
1138 pgd = (pgd_t *)xen_start_info->pt_base;
1140 /* Don't do the full vcpu_info placement stuff until we have a
1141 possible map and a non-dummy shared_info. */
1142 per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1144 local_irq_disable();
1145 early_boot_irqs_off();
1147 xen_raw_console_write("mapping kernel into physical memory\n");
1148 pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages);
1152 /* keep using Xen gdt for now; no urgent need to change it */
1154 pv_info.kernel_rpl = 1;
1155 if (xen_feature(XENFEAT_supervisor_mode_kernel))
1156 pv_info.kernel_rpl = 0;
1158 /* set the limit of our address space */
1161 #ifdef CONFIG_X86_32
1162 /* set up basic CPUID stuff */
1163 cpu_detect(&new_cpu_data);
1164 new_cpu_data.hard_math = 1;
1165 new_cpu_data.wp_works_ok = 1;
1166 new_cpu_data.x86_capability[0] = cpuid_edx(1);
1169 /* Poke various useful things into boot_params */
1170 boot_params.hdr.type_of_loader = (9 << 4) | 0;
1171 boot_params.hdr.ramdisk_image = xen_start_info->mod_start
1172 ? __pa(xen_start_info->mod_start) : 0;
1173 boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
1174 boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
1176 if (!xen_initial_domain()) {
1177 add_preferred_console("xenboot", 0, NULL);
1178 add_preferred_console("tty", 0, NULL);
1179 add_preferred_console("hvc", 0, NULL);
1181 /* Make sure ACS will be enabled */
1186 xen_raw_console_write("about to get started...\n");
1188 xen_setup_runstate_info(0);
1190 /* Start the world */
1191 #ifdef CONFIG_X86_32
1192 i386_start_kernel();
1194 x86_64_start_reservations((char *)__pa_symbol(&boot_params));