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>
35 #include <xen/interface/xen.h>
36 #include <xen/interface/version.h>
37 #include <xen/interface/physdev.h>
38 #include <xen/interface/vcpu.h>
39 #include <xen/interface/memory.h>
40 #include <xen/features.h>
43 #include <xen/hvc-console.h>
45 #include <asm/paravirt.h>
48 #include <asm/xen/hypercall.h>
49 #include <asm/xen/hypervisor.h>
50 #include <asm/fixmap.h>
51 #include <asm/processor.h>
52 #include <asm/proto.h>
53 #include <asm/msr-index.h>
54 #include <asm/traps.h>
55 #include <asm/setup.h>
57 #include <asm/pgalloc.h>
58 #include <asm/pgtable.h>
59 #include <asm/tlbflush.h>
60 #include <asm/reboot.h>
61 #include <asm/setup.h>
62 #include <asm/stackprotector.h>
63 #include <asm/hypervisor.h>
67 #include "multicalls.h"
69 EXPORT_SYMBOL_GPL(hypercall_page);
71 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
72 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
74 enum xen_domain_type xen_domain_type = XEN_NATIVE;
75 EXPORT_SYMBOL_GPL(xen_domain_type);
77 struct start_info *xen_start_info;
78 EXPORT_SYMBOL_GPL(xen_start_info);
80 struct shared_info xen_dummy_shared_info;
82 void *xen_initial_gdt;
84 RESERVE_BRK(shared_info_page_brk, PAGE_SIZE);
85 __read_mostly int xen_have_vector_callback;
86 EXPORT_SYMBOL_GPL(xen_have_vector_callback);
89 * Point at some empty memory to start with. We map the real shared_info
90 * page as soon as fixmap is up and running.
92 struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
95 * Flag to determine whether vcpu info placement is available on all
96 * VCPUs. We assume it is to start with, and then set it to zero on
97 * the first failure. This is because it can succeed on some VCPUs
98 * and not others, since it can involve hypervisor memory allocation,
99 * or because the guest failed to guarantee all the appropriate
100 * constraints on all VCPUs (ie buffer can't cross a page boundary).
102 * Note that any particular CPU may be using a placed vcpu structure,
103 * but we can only optimise if the all are.
105 * 0: not available, 1: available
107 static int have_vcpu_info_placement = 1;
109 static void clamp_max_cpus(void)
112 if (setup_max_cpus > MAX_VIRT_CPUS)
113 setup_max_cpus = MAX_VIRT_CPUS;
117 static void xen_vcpu_setup(int cpu)
119 struct vcpu_register_vcpu_info info;
121 struct vcpu_info *vcpup;
123 BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
125 if (cpu < MAX_VIRT_CPUS)
126 per_cpu(xen_vcpu,cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
128 if (!have_vcpu_info_placement) {
129 if (cpu >= MAX_VIRT_CPUS)
134 vcpup = &per_cpu(xen_vcpu_info, cpu);
135 info.mfn = arbitrary_virt_to_mfn(vcpup);
136 info.offset = offset_in_page(vcpup);
138 printk(KERN_DEBUG "trying to map vcpu_info %d at %p, mfn %llx, offset %d\n",
139 cpu, vcpup, info.mfn, info.offset);
141 /* Check to see if the hypervisor will put the vcpu_info
142 structure where we want it, which allows direct access via
143 a percpu-variable. */
144 err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
147 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
148 have_vcpu_info_placement = 0;
151 /* This cpu is using the registered vcpu info, even if
152 later ones fail to. */
153 per_cpu(xen_vcpu, cpu) = vcpup;
155 printk(KERN_DEBUG "cpu %d using vcpu_info at %p\n",
161 * On restore, set the vcpu placement up again.
162 * If it fails, then we're in a bad state, since
163 * we can't back out from using it...
165 void xen_vcpu_restore(void)
169 for_each_online_cpu(cpu) {
170 bool other_cpu = (cpu != smp_processor_id());
173 HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL))
176 xen_setup_runstate_info(cpu);
178 if (have_vcpu_info_placement)
182 HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
187 static void __init xen_banner(void)
189 unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
190 struct xen_extraversion extra;
191 HYPERVISOR_xen_version(XENVER_extraversion, &extra);
193 printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
195 printk(KERN_INFO "Xen version: %d.%d%s%s\n",
196 version >> 16, version & 0xffff, extra.extraversion,
197 xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
200 static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
201 static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
203 static void xen_cpuid(unsigned int *ax, unsigned int *bx,
204 unsigned int *cx, unsigned int *dx)
206 unsigned maskebx = ~0;
207 unsigned maskecx = ~0;
208 unsigned maskedx = ~0;
211 * Mask out inconvenient features, to try and disable as many
212 * unsupported kernel subsystems as possible.
216 maskecx = cpuid_leaf1_ecx_mask;
217 maskedx = cpuid_leaf1_edx_mask;
221 /* Suppress extended topology stuff */
226 asm(XEN_EMULATE_PREFIX "cpuid"
231 : "0" (*ax), "2" (*cx));
238 static __init void xen_init_cpuid_mask(void)
240 unsigned int ax, bx, cx, dx;
242 cpuid_leaf1_edx_mask =
243 ~((1 << X86_FEATURE_MCE) | /* disable MCE */
244 (1 << X86_FEATURE_MCA) | /* disable MCA */
245 (1 << X86_FEATURE_ACC)); /* thermal monitoring */
247 if (!xen_initial_domain())
248 cpuid_leaf1_edx_mask &=
249 ~((1 << X86_FEATURE_APIC) | /* disable local APIC */
250 (1 << X86_FEATURE_ACPI)); /* disable ACPI */
254 xen_cpuid(&ax, &bx, &cx, &dx);
256 /* cpuid claims we support xsave; try enabling it to see what happens */
257 if (cx & (1 << (X86_FEATURE_XSAVE % 32))) {
260 set_in_cr4(X86_CR4_OSXSAVE);
264 if ((cr4 & X86_CR4_OSXSAVE) == 0)
265 cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_XSAVE % 32));
267 clear_in_cr4(X86_CR4_OSXSAVE);
271 static void xen_set_debugreg(int reg, unsigned long val)
273 HYPERVISOR_set_debugreg(reg, val);
276 static unsigned long xen_get_debugreg(int reg)
278 return HYPERVISOR_get_debugreg(reg);
281 static void xen_end_context_switch(struct task_struct *next)
284 paravirt_end_context_switch(next);
287 static unsigned long xen_store_tr(void)
293 * Set the page permissions for a particular virtual address. If the
294 * address is a vmalloc mapping (or other non-linear mapping), then
295 * find the linear mapping of the page and also set its protections to
298 static void set_aliased_prot(void *v, pgprot_t prot)
306 ptep = lookup_address((unsigned long)v, &level);
307 BUG_ON(ptep == NULL);
309 pfn = pte_pfn(*ptep);
310 page = pfn_to_page(pfn);
312 pte = pfn_pte(pfn, prot);
314 if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
317 if (!PageHighMem(page)) {
318 void *av = __va(PFN_PHYS(pfn));
321 if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
327 static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
329 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
332 for(i = 0; i < entries; i += entries_per_page)
333 set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
336 static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
338 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
341 for(i = 0; i < entries; i += entries_per_page)
342 set_aliased_prot(ldt + i, PAGE_KERNEL);
345 static void xen_set_ldt(const void *addr, unsigned entries)
347 struct mmuext_op *op;
348 struct multicall_space mcs = xen_mc_entry(sizeof(*op));
351 op->cmd = MMUEXT_SET_LDT;
352 op->arg1.linear_addr = (unsigned long)addr;
353 op->arg2.nr_ents = entries;
355 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
357 xen_mc_issue(PARAVIRT_LAZY_CPU);
360 static void xen_load_gdt(const struct desc_ptr *dtr)
362 unsigned long va = dtr->address;
363 unsigned int size = dtr->size + 1;
364 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
365 unsigned long frames[pages];
369 * A GDT can be up to 64k in size, which corresponds to 8192
370 * 8-byte entries, or 16 4k pages..
373 BUG_ON(size > 65536);
374 BUG_ON(va & ~PAGE_MASK);
376 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
379 unsigned long pfn, mfn;
383 * The GDT is per-cpu and is in the percpu data area.
384 * That can be virtually mapped, so we need to do a
385 * page-walk to get the underlying MFN for the
386 * hypercall. The page can also be in the kernel's
387 * linear range, so we need to RO that mapping too.
389 ptep = lookup_address(va, &level);
390 BUG_ON(ptep == NULL);
392 pfn = pte_pfn(*ptep);
393 mfn = pfn_to_mfn(pfn);
394 virt = __va(PFN_PHYS(pfn));
398 make_lowmem_page_readonly((void *)va);
399 make_lowmem_page_readonly(virt);
402 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
407 * load_gdt for early boot, when the gdt is only mapped once
409 static __init void xen_load_gdt_boot(const struct desc_ptr *dtr)
411 unsigned long va = dtr->address;
412 unsigned int size = dtr->size + 1;
413 unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
414 unsigned long frames[pages];
418 * A GDT can be up to 64k in size, which corresponds to 8192
419 * 8-byte entries, or 16 4k pages..
422 BUG_ON(size > 65536);
423 BUG_ON(va & ~PAGE_MASK);
425 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
427 unsigned long pfn, mfn;
429 pfn = virt_to_pfn(va);
430 mfn = pfn_to_mfn(pfn);
432 pte = pfn_pte(pfn, PAGE_KERNEL_RO);
434 if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0))
440 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
444 static void load_TLS_descriptor(struct thread_struct *t,
445 unsigned int cpu, unsigned int i)
447 struct desc_struct *gdt = get_cpu_gdt_table(cpu);
448 xmaddr_t maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
449 struct multicall_space mc = __xen_mc_entry(0);
451 MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
454 static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
457 * XXX sleazy hack: If we're being called in a lazy-cpu zone
458 * and lazy gs handling is enabled, it means we're in a
459 * context switch, and %gs has just been saved. This means we
460 * can zero it out to prevent faults on exit from the
461 * hypervisor if the next process has no %gs. Either way, it
462 * has been saved, and the new value will get loaded properly.
463 * This will go away as soon as Xen has been modified to not
464 * save/restore %gs for normal hypercalls.
466 * On x86_64, this hack is not used for %gs, because gs points
467 * to KERNEL_GS_BASE (and uses it for PDA references), so we
468 * must not zero %gs on x86_64
470 * For x86_64, we need to zero %fs, otherwise we may get an
471 * exception between the new %fs descriptor being loaded and
472 * %fs being effectively cleared at __switch_to().
474 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
484 load_TLS_descriptor(t, cpu, 0);
485 load_TLS_descriptor(t, cpu, 1);
486 load_TLS_descriptor(t, cpu, 2);
488 xen_mc_issue(PARAVIRT_LAZY_CPU);
492 static void xen_load_gs_index(unsigned int idx)
494 if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
499 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
502 xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
503 u64 entry = *(u64 *)ptr;
508 if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
514 static int cvt_gate_to_trap(int vector, const gate_desc *val,
515 struct trap_info *info)
519 if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT)
522 info->vector = vector;
524 addr = gate_offset(*val);
527 * Look for known traps using IST, and substitute them
528 * appropriately. The debugger ones are the only ones we care
529 * about. Xen will handle faults like double_fault and
530 * machine_check, so we should never see them. Warn if
531 * there's an unexpected IST-using fault handler.
533 if (addr == (unsigned long)debug)
534 addr = (unsigned long)xen_debug;
535 else if (addr == (unsigned long)int3)
536 addr = (unsigned long)xen_int3;
537 else if (addr == (unsigned long)stack_segment)
538 addr = (unsigned long)xen_stack_segment;
539 else if (addr == (unsigned long)double_fault ||
540 addr == (unsigned long)nmi) {
541 /* Don't need to handle these */
543 #ifdef CONFIG_X86_MCE
544 } else if (addr == (unsigned long)machine_check) {
548 /* Some other trap using IST? */
549 if (WARN_ON(val->ist != 0))
552 #endif /* CONFIG_X86_64 */
553 info->address = addr;
555 info->cs = gate_segment(*val);
556 info->flags = val->dpl;
557 /* interrupt gates clear IF */
558 if (val->type == GATE_INTERRUPT)
559 info->flags |= 1 << 2;
564 /* Locations of each CPU's IDT */
565 static DEFINE_PER_CPU(struct desc_ptr, idt_desc);
567 /* Set an IDT entry. If the entry is part of the current IDT, then
569 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
571 unsigned long p = (unsigned long)&dt[entrynum];
572 unsigned long start, end;
576 start = __get_cpu_var(idt_desc).address;
577 end = start + __get_cpu_var(idt_desc).size + 1;
581 native_write_idt_entry(dt, entrynum, g);
583 if (p >= start && (p + 8) <= end) {
584 struct trap_info info[2];
588 if (cvt_gate_to_trap(entrynum, g, &info[0]))
589 if (HYPERVISOR_set_trap_table(info))
596 static void xen_convert_trap_info(const struct desc_ptr *desc,
597 struct trap_info *traps)
599 unsigned in, out, count;
601 count = (desc->size+1) / sizeof(gate_desc);
604 for (in = out = 0; in < count; in++) {
605 gate_desc *entry = (gate_desc*)(desc->address) + in;
607 if (cvt_gate_to_trap(in, entry, &traps[out]))
610 traps[out].address = 0;
613 void xen_copy_trap_info(struct trap_info *traps)
615 const struct desc_ptr *desc = &__get_cpu_var(idt_desc);
617 xen_convert_trap_info(desc, traps);
620 /* Load a new IDT into Xen. In principle this can be per-CPU, so we
621 hold a spinlock to protect the static traps[] array (static because
622 it avoids allocation, and saves stack space). */
623 static void xen_load_idt(const struct desc_ptr *desc)
625 static DEFINE_SPINLOCK(lock);
626 static struct trap_info traps[257];
630 __get_cpu_var(idt_desc) = *desc;
632 xen_convert_trap_info(desc, traps);
635 if (HYPERVISOR_set_trap_table(traps))
641 /* Write a GDT descriptor entry. Ignore LDT descriptors, since
642 they're handled differently. */
643 static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
644 const void *desc, int type)
655 xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]);
658 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
668 * Version of write_gdt_entry for use at early boot-time needed to
669 * update an entry as simply as possible.
671 static __init void xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
672 const void *desc, int type)
681 xmaddr_t maddr = virt_to_machine(&dt[entry]);
683 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
684 dt[entry] = *(struct desc_struct *)desc;
690 static void xen_load_sp0(struct tss_struct *tss,
691 struct thread_struct *thread)
693 struct multicall_space mcs = xen_mc_entry(0);
694 MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
695 xen_mc_issue(PARAVIRT_LAZY_CPU);
698 static void xen_set_iopl_mask(unsigned mask)
700 struct physdev_set_iopl set_iopl;
702 /* Force the change at ring 0. */
703 set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
704 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
707 static void xen_io_delay(void)
711 #ifdef CONFIG_X86_LOCAL_APIC
712 static u32 xen_apic_read(u32 reg)
717 static void xen_apic_write(u32 reg, u32 val)
719 /* Warn to see if there's any stray references */
723 static u64 xen_apic_icr_read(void)
728 static void xen_apic_icr_write(u32 low, u32 id)
730 /* Warn to see if there's any stray references */
734 static void xen_apic_wait_icr_idle(void)
739 static u32 xen_safe_apic_wait_icr_idle(void)
744 static void set_xen_basic_apic_ops(void)
746 apic->read = xen_apic_read;
747 apic->write = xen_apic_write;
748 apic->icr_read = xen_apic_icr_read;
749 apic->icr_write = xen_apic_icr_write;
750 apic->wait_icr_idle = xen_apic_wait_icr_idle;
751 apic->safe_wait_icr_idle = xen_safe_apic_wait_icr_idle;
756 static void xen_clts(void)
758 struct multicall_space mcs;
760 mcs = xen_mc_entry(0);
762 MULTI_fpu_taskswitch(mcs.mc, 0);
764 xen_mc_issue(PARAVIRT_LAZY_CPU);
767 static DEFINE_PER_CPU(unsigned long, xen_cr0_value);
769 static unsigned long xen_read_cr0(void)
771 unsigned long cr0 = percpu_read(xen_cr0_value);
773 if (unlikely(cr0 == 0)) {
774 cr0 = native_read_cr0();
775 percpu_write(xen_cr0_value, cr0);
781 static void xen_write_cr0(unsigned long cr0)
783 struct multicall_space mcs;
785 percpu_write(xen_cr0_value, cr0);
787 /* Only pay attention to cr0.TS; everything else is
789 mcs = xen_mc_entry(0);
791 MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
793 xen_mc_issue(PARAVIRT_LAZY_CPU);
796 static void xen_write_cr4(unsigned long cr4)
801 native_write_cr4(cr4);
804 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
815 case MSR_FS_BASE: which = SEGBASE_FS; goto set;
816 case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set;
817 case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set;
820 base = ((u64)high << 32) | low;
821 if (HYPERVISOR_set_segment_base(which, base) != 0)
829 case MSR_SYSCALL_MASK:
830 case MSR_IA32_SYSENTER_CS:
831 case MSR_IA32_SYSENTER_ESP:
832 case MSR_IA32_SYSENTER_EIP:
833 /* Fast syscall setup is all done in hypercalls, so
834 these are all ignored. Stub them out here to stop
835 Xen console noise. */
839 ret = native_write_msr_safe(msr, low, high);
845 void xen_setup_shared_info(void)
847 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
848 set_fixmap(FIX_PARAVIRT_BOOTMAP,
849 xen_start_info->shared_info);
851 HYPERVISOR_shared_info =
852 (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
854 HYPERVISOR_shared_info =
855 (struct shared_info *)__va(xen_start_info->shared_info);
858 /* In UP this is as good a place as any to set up shared info */
859 xen_setup_vcpu_info_placement();
862 xen_setup_mfn_list_list();
865 /* This is called once we have the cpu_possible_map */
866 void xen_setup_vcpu_info_placement(void)
870 for_each_possible_cpu(cpu)
873 /* xen_vcpu_setup managed to place the vcpu_info within the
874 percpu area for all cpus, so make use of it */
875 if (have_vcpu_info_placement) {
876 printk(KERN_INFO "Xen: using vcpu_info placement\n");
878 pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
879 pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct);
880 pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
881 pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
882 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
886 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
887 unsigned long addr, unsigned len)
889 char *start, *end, *reloc;
892 start = end = reloc = NULL;
894 #define SITE(op, x) \
895 case PARAVIRT_PATCH(op.x): \
896 if (have_vcpu_info_placement) { \
897 start = (char *)xen_##x##_direct; \
898 end = xen_##x##_direct_end; \
899 reloc = xen_##x##_direct_reloc; \
904 SITE(pv_irq_ops, irq_enable);
905 SITE(pv_irq_ops, irq_disable);
906 SITE(pv_irq_ops, save_fl);
907 SITE(pv_irq_ops, restore_fl);
911 if (start == NULL || (end-start) > len)
914 ret = paravirt_patch_insns(insnbuf, len, start, end);
916 /* Note: because reloc is assigned from something that
917 appears to be an array, gcc assumes it's non-null,
918 but doesn't know its relationship with start and
920 if (reloc > start && reloc < end) {
921 int reloc_off = reloc - start;
922 long *relocp = (long *)(insnbuf + reloc_off);
923 long delta = start - (char *)addr;
931 ret = paravirt_patch_default(type, clobbers, insnbuf,
939 static const struct pv_info xen_info __initdata = {
940 .paravirt_enabled = 1,
941 .shared_kernel_pmd = 0,
946 static const struct pv_init_ops xen_init_ops __initdata = {
950 static const struct pv_cpu_ops xen_cpu_ops __initdata = {
953 .set_debugreg = xen_set_debugreg,
954 .get_debugreg = xen_get_debugreg,
958 .read_cr0 = xen_read_cr0,
959 .write_cr0 = xen_write_cr0,
961 .read_cr4 = native_read_cr4,
962 .read_cr4_safe = native_read_cr4_safe,
963 .write_cr4 = xen_write_cr4,
965 .wbinvd = native_wbinvd,
967 .read_msr = native_read_msr_safe,
968 .write_msr = xen_write_msr_safe,
969 .read_tsc = native_read_tsc,
970 .read_pmc = native_read_pmc,
973 .irq_enable_sysexit = xen_sysexit,
975 .usergs_sysret32 = xen_sysret32,
976 .usergs_sysret64 = xen_sysret64,
979 .load_tr_desc = paravirt_nop,
980 .set_ldt = xen_set_ldt,
981 .load_gdt = xen_load_gdt,
982 .load_idt = xen_load_idt,
983 .load_tls = xen_load_tls,
985 .load_gs_index = xen_load_gs_index,
988 .alloc_ldt = xen_alloc_ldt,
989 .free_ldt = xen_free_ldt,
991 .store_gdt = native_store_gdt,
992 .store_idt = native_store_idt,
993 .store_tr = xen_store_tr,
995 .write_ldt_entry = xen_write_ldt_entry,
996 .write_gdt_entry = xen_write_gdt_entry,
997 .write_idt_entry = xen_write_idt_entry,
998 .load_sp0 = xen_load_sp0,
1000 .set_iopl_mask = xen_set_iopl_mask,
1001 .io_delay = xen_io_delay,
1003 /* Xen takes care of %gs when switching to usermode for us */
1004 .swapgs = paravirt_nop,
1006 .start_context_switch = paravirt_start_context_switch,
1007 .end_context_switch = xen_end_context_switch,
1010 static const struct pv_apic_ops xen_apic_ops __initdata = {
1011 #ifdef CONFIG_X86_LOCAL_APIC
1012 .startup_ipi_hook = paravirt_nop,
1016 static void xen_reboot(int reason)
1018 struct sched_shutdown r = { .reason = reason };
1024 if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
1028 static void xen_restart(char *msg)
1030 xen_reboot(SHUTDOWN_reboot);
1033 static void xen_emergency_restart(void)
1035 xen_reboot(SHUTDOWN_reboot);
1038 static void xen_machine_halt(void)
1040 xen_reboot(SHUTDOWN_poweroff);
1043 static void xen_crash_shutdown(struct pt_regs *regs)
1045 xen_reboot(SHUTDOWN_crash);
1049 xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
1051 xen_reboot(SHUTDOWN_crash);
1055 static struct notifier_block xen_panic_block = {
1056 .notifier_call= xen_panic_event,
1059 int xen_panic_handler_init(void)
1061 atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block);
1065 static const struct machine_ops __initdata xen_machine_ops = {
1066 .restart = xen_restart,
1067 .halt = xen_machine_halt,
1068 .power_off = xen_machine_halt,
1069 .shutdown = xen_machine_halt,
1070 .crash_shutdown = xen_crash_shutdown,
1071 .emergency_restart = xen_emergency_restart,
1075 * Set up the GDT and segment registers for -fstack-protector. Until
1076 * we do this, we have to be careful not to call any stack-protected
1077 * function, which is most of the kernel.
1079 static void __init xen_setup_stackprotector(void)
1081 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
1082 pv_cpu_ops.load_gdt = xen_load_gdt_boot;
1084 setup_stack_canary_segment(0);
1085 switch_to_new_gdt(0);
1087 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry;
1088 pv_cpu_ops.load_gdt = xen_load_gdt;
1091 /* First C function to be called on Xen boot */
1092 asmlinkage void __init xen_start_kernel(void)
1096 if (!xen_start_info)
1099 xen_domain_type = XEN_PV_DOMAIN;
1101 /* Install Xen paravirt ops */
1103 pv_init_ops = xen_init_ops;
1104 pv_cpu_ops = xen_cpu_ops;
1105 pv_apic_ops = xen_apic_ops;
1107 x86_init.resources.memory_setup = xen_memory_setup;
1108 x86_init.oem.arch_setup = xen_arch_setup;
1109 x86_init.oem.banner = xen_banner;
1111 xen_init_time_ops();
1114 * Set up some pagetable state before starting to set any ptes.
1119 /* Prevent unwanted bits from being set in PTEs. */
1120 __supported_pte_mask &= ~_PAGE_GLOBAL;
1121 if (!xen_initial_domain())
1122 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
1124 __supported_pte_mask |= _PAGE_IOMAP;
1127 * Prevent page tables from being allocated in highmem, even
1128 * if CONFIG_HIGHPTE is enabled.
1130 __userpte_alloc_gfp &= ~__GFP_HIGHMEM;
1132 /* Work out if we support NX */
1135 xen_setup_features();
1138 if (!xen_feature(XENFEAT_auto_translated_physmap))
1139 xen_build_dynamic_phys_to_machine();
1142 * Set up kernel GDT and segment registers, mainly so that
1143 * -fstack-protector code can be executed.
1145 xen_setup_stackprotector();
1148 xen_init_cpuid_mask();
1150 #ifdef CONFIG_X86_LOCAL_APIC
1152 * set up the basic apic ops.
1154 set_xen_basic_apic_ops();
1157 if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
1158 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
1159 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
1162 machine_ops = xen_machine_ops;
1165 * The only reliable way to retain the initial address of the
1166 * percpu gdt_page is to remember it here, so we can go and
1167 * mark it RW later, when the initial percpu area is freed.
1169 xen_initial_gdt = &per_cpu(gdt_page, 0);
1173 pgd = (pgd_t *)xen_start_info->pt_base;
1175 if (!xen_initial_domain())
1176 __supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
1178 __supported_pte_mask |= _PAGE_IOMAP;
1179 /* Don't do the full vcpu_info placement stuff until we have a
1180 possible map and a non-dummy shared_info. */
1181 per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1183 local_irq_disable();
1184 early_boot_irqs_off();
1186 xen_raw_console_write("mapping kernel into physical memory\n");
1187 pgd = xen_setup_kernel_pagetable(pgd, xen_start_info->nr_pages);
1191 /* keep using Xen gdt for now; no urgent need to change it */
1193 #ifdef CONFIG_X86_32
1194 pv_info.kernel_rpl = 1;
1195 if (xen_feature(XENFEAT_supervisor_mode_kernel))
1196 pv_info.kernel_rpl = 0;
1198 pv_info.kernel_rpl = 0;
1201 /* set the limit of our address space */
1204 #ifdef CONFIG_X86_32
1205 /* set up basic CPUID stuff */
1206 cpu_detect(&new_cpu_data);
1207 new_cpu_data.hard_math = 1;
1208 new_cpu_data.wp_works_ok = 1;
1209 new_cpu_data.x86_capability[0] = cpuid_edx(1);
1212 /* Poke various useful things into boot_params */
1213 boot_params.hdr.type_of_loader = (9 << 4) | 0;
1214 boot_params.hdr.ramdisk_image = xen_start_info->mod_start
1215 ? __pa(xen_start_info->mod_start) : 0;
1216 boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
1217 boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
1219 if (!xen_initial_domain()) {
1220 add_preferred_console("xenboot", 0, NULL);
1221 add_preferred_console("tty", 0, NULL);
1222 add_preferred_console("hvc", 0, NULL);
1224 /* Make sure ACS will be enabled */
1229 xen_raw_console_write("about to get started...\n");
1231 xen_setup_runstate_info(0);
1233 /* Start the world */
1234 #ifdef CONFIG_X86_32
1235 i386_start_kernel();
1237 x86_64_start_reservations((char *)__pa_symbol(&boot_params));
1241 static uint32_t xen_cpuid_base(void)
1243 uint32_t base, eax, ebx, ecx, edx;
1246 for (base = 0x40000000; base < 0x40010000; base += 0x100) {
1247 cpuid(base, &eax, &ebx, &ecx, &edx);
1248 *(uint32_t *)(signature + 0) = ebx;
1249 *(uint32_t *)(signature + 4) = ecx;
1250 *(uint32_t *)(signature + 8) = edx;
1253 if (!strcmp("XenVMMXenVMM", signature) && ((eax - base) >= 2))
1260 static int init_hvm_pv_info(int *major, int *minor)
1262 uint32_t eax, ebx, ecx, edx, pages, msr, base;
1265 base = xen_cpuid_base();
1266 cpuid(base + 1, &eax, &ebx, &ecx, &edx);
1269 *minor = eax & 0xffff;
1270 printk(KERN_INFO "Xen version %d.%d.\n", *major, *minor);
1272 cpuid(base + 2, &pages, &msr, &ecx, &edx);
1274 pfn = __pa(hypercall_page);
1275 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
1277 xen_setup_features();
1280 pv_info.kernel_rpl = 0;
1282 xen_domain_type = XEN_HVM_DOMAIN;
1287 void xen_hvm_init_shared_info(void)
1290 struct xen_add_to_physmap xatp;
1291 static struct shared_info *shared_info_page = 0;
1293 if (!shared_info_page)
1294 shared_info_page = (struct shared_info *)
1295 extend_brk(PAGE_SIZE, PAGE_SIZE);
1296 xatp.domid = DOMID_SELF;
1298 xatp.space = XENMAPSPACE_shared_info;
1299 xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
1300 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
1303 HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
1305 /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
1306 * page, we use it in the event channel upcall and in some pvclock
1307 * related functions. We don't need the vcpu_info placement
1308 * optimizations because we don't use any pv_mmu or pv_irq op on
1310 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
1311 * online but xen_hvm_init_shared_info is run at resume time too and
1312 * in that case multiple vcpus might be online. */
1313 for_each_online_cpu(cpu) {
1314 per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
1318 #ifdef CONFIG_XEN_PVHVM
1319 static int __cpuinit xen_hvm_cpu_notify(struct notifier_block *self,
1320 unsigned long action, void *hcpu)
1322 int cpu = (long)hcpu;
1324 case CPU_UP_PREPARE:
1325 per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
1333 static struct notifier_block __cpuinitdata xen_hvm_cpu_notifier = {
1334 .notifier_call = xen_hvm_cpu_notify,
1337 static void __init xen_hvm_guest_init(void)
1342 r = init_hvm_pv_info(&major, &minor);
1346 xen_hvm_init_shared_info();
1348 if (xen_feature(XENFEAT_hvm_callback_vector))
1349 xen_have_vector_callback = 1;
1350 register_cpu_notifier(&xen_hvm_cpu_notifier);
1351 xen_unplug_emulated_devices();
1352 have_vcpu_info_placement = 0;
1353 x86_init.irqs.intr_init = xen_init_IRQ;
1354 xen_hvm_init_time_ops();
1355 xen_hvm_init_mmu_ops();
1358 static bool __init xen_hvm_platform(void)
1360 if (xen_pv_domain())
1363 if (!xen_cpuid_base())
1369 const __refconst struct hypervisor_x86 x86_hyper_xen_hvm = {
1371 .detect = xen_hvm_platform,
1372 .init_platform = xen_hvm_guest_init,
1374 EXPORT_SYMBOL(x86_hyper_xen_hvm);