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/export.h>
28 #include <linux/page-flags.h>
29 #include <linux/highmem.h>
30 #include <linux/console.h>
31 #include <linux/pci.h>
32 #include <linux/gfp.h>
33 #include <linux/memblock.h>
34 #include <linux/edd.h>
35 #include <linux/frame.h>
37 #include <linux/kexec.h>
40 #include <xen/events.h>
41 #include <xen/interface/xen.h>
42 #include <xen/interface/version.h>
43 #include <xen/interface/physdev.h>
44 #include <xen/interface/vcpu.h>
45 #include <xen/interface/memory.h>
46 #include <xen/interface/nmi.h>
47 #include <xen/interface/xen-mca.h>
48 #include <xen/features.h>
51 #include <xen/hvc-console.h>
54 #include <asm/paravirt.h>
57 #include <asm/xen/pci.h>
58 #include <asm/xen/hypercall.h>
59 #include <asm/xen/hypervisor.h>
60 #include <asm/xen/cpuid.h>
61 #include <asm/fixmap.h>
62 #include <asm/processor.h>
63 #include <asm/proto.h>
64 #include <asm/msr-index.h>
65 #include <asm/traps.h>
66 #include <asm/setup.h>
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 /* Linux <-> Xen vCPU id mapping */
121 DEFINE_PER_CPU(int, xen_vcpu_id) = -1;
122 EXPORT_PER_CPU_SYMBOL(xen_vcpu_id);
124 enum xen_domain_type xen_domain_type = XEN_NATIVE;
125 EXPORT_SYMBOL_GPL(xen_domain_type);
127 unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START;
128 EXPORT_SYMBOL(machine_to_phys_mapping);
129 unsigned long machine_to_phys_nr;
130 EXPORT_SYMBOL(machine_to_phys_nr);
132 struct start_info *xen_start_info;
133 EXPORT_SYMBOL_GPL(xen_start_info);
135 struct shared_info xen_dummy_shared_info;
137 void *xen_initial_gdt;
139 RESERVE_BRK(shared_info_page_brk, PAGE_SIZE);
140 __read_mostly int xen_have_vector_callback;
141 EXPORT_SYMBOL_GPL(xen_have_vector_callback);
144 * Point at some empty memory to start with. We map the real shared_info
145 * page as soon as fixmap is up and running.
147 struct shared_info *HYPERVISOR_shared_info = &xen_dummy_shared_info;
150 * Flag to determine whether vcpu info placement is available on all
151 * VCPUs. We assume it is to start with, and then set it to zero on
152 * the first failure. This is because it can succeed on some VCPUs
153 * and not others, since it can involve hypervisor memory allocation,
154 * or because the guest failed to guarantee all the appropriate
155 * constraints on all VCPUs (ie buffer can't cross a page boundary).
157 * Note that any particular CPU may be using a placed vcpu structure,
158 * but we can only optimise if the all are.
160 * 0: not available, 1: available
162 static int have_vcpu_info_placement = 1;
165 struct desc_struct desc[3];
169 * Updating the 3 TLS descriptors in the GDT on every task switch is
170 * surprisingly expensive so we avoid updating them if they haven't
171 * changed. Since Xen writes different descriptors than the one
172 * passed in the update_descriptor hypercall we keep shadow copies to
175 static DEFINE_PER_CPU(struct tls_descs, shadow_tls_desc);
177 static void clamp_max_cpus(void)
180 if (setup_max_cpus > MAX_VIRT_CPUS)
181 setup_max_cpus = MAX_VIRT_CPUS;
185 void xen_vcpu_setup(int cpu)
187 struct vcpu_register_vcpu_info info;
189 struct vcpu_info *vcpup;
191 BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
194 * This path is called twice on PVHVM - first during bootup via
195 * smp_init -> xen_hvm_cpu_notify, and then if the VCPU is being
196 * hotplugged: cpu_up -> xen_hvm_cpu_notify.
197 * As we can only do the VCPUOP_register_vcpu_info once lets
198 * not over-write its result.
200 * For PV it is called during restore (xen_vcpu_restore) and bootup
201 * (xen_setup_vcpu_info_placement). The hotplug mechanism does not
204 if (xen_hvm_domain()) {
205 if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu))
208 if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS)
209 per_cpu(xen_vcpu, cpu) =
210 &HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
212 if (!have_vcpu_info_placement) {
213 if (cpu >= MAX_VIRT_CPUS)
218 vcpup = &per_cpu(xen_vcpu_info, cpu);
219 info.mfn = arbitrary_virt_to_mfn(vcpup);
220 info.offset = offset_in_page(vcpup);
222 /* Check to see if the hypervisor will put the vcpu_info
223 structure where we want it, which allows direct access via
225 N.B. This hypercall can _only_ be called once per CPU. Subsequent
226 calls will error out with -EINVAL. This is due to the fact that
227 hypervisor has no unregister variant and this hypercall does not
228 allow to over-write info.mfn and info.offset.
230 err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
234 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
235 have_vcpu_info_placement = 0;
238 /* This cpu is using the registered vcpu info, even if
239 later ones fail to. */
240 per_cpu(xen_vcpu, cpu) = vcpup;
245 * On restore, set the vcpu placement up again.
246 * If it fails, then we're in a bad state, since
247 * we can't back out from using it...
249 void xen_vcpu_restore(void)
253 for_each_possible_cpu(cpu) {
254 bool other_cpu = (cpu != smp_processor_id());
255 bool is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up, xen_vcpu_nr(cpu),
258 if (other_cpu && is_up &&
259 HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(cpu), NULL))
262 xen_setup_runstate_info(cpu);
264 if (have_vcpu_info_placement)
267 if (other_cpu && is_up &&
268 HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL))
273 static void __init xen_banner(void)
275 unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
276 struct xen_extraversion extra;
277 HYPERVISOR_xen_version(XENVER_extraversion, &extra);
279 pr_info("Booting paravirtualized kernel %son %s\n",
280 xen_feature(XENFEAT_auto_translated_physmap) ?
281 "with PVH extensions " : "", pv_info.name);
282 printk(KERN_INFO "Xen version: %d.%d%s%s\n",
283 version >> 16, version & 0xffff, extra.extraversion,
284 xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
286 /* Check if running on Xen version (major, minor) or later */
288 xen_running_on_version_or_later(unsigned int major, unsigned int minor)
290 unsigned int version;
295 version = HYPERVISOR_xen_version(XENVER_version, NULL);
296 if ((((version >> 16) == major) && ((version & 0xffff) >= minor)) ||
297 ((version >> 16) > major))
302 #define CPUID_THERM_POWER_LEAF 6
303 #define APERFMPERF_PRESENT 0
305 static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
306 static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
308 static __read_mostly unsigned int cpuid_leaf1_ecx_set_mask;
309 static __read_mostly unsigned int cpuid_leaf5_ecx_val;
310 static __read_mostly unsigned int cpuid_leaf5_edx_val;
312 static void xen_cpuid(unsigned int *ax, unsigned int *bx,
313 unsigned int *cx, unsigned int *dx)
315 unsigned maskebx = ~0;
316 unsigned maskecx = ~0;
317 unsigned maskedx = ~0;
320 * Mask out inconvenient features, to try and disable as many
321 * unsupported kernel subsystems as possible.
325 maskecx = cpuid_leaf1_ecx_mask;
326 setecx = cpuid_leaf1_ecx_set_mask;
327 maskedx = cpuid_leaf1_edx_mask;
330 case CPUID_MWAIT_LEAF:
331 /* Synthesize the values.. */
334 *cx = cpuid_leaf5_ecx_val;
335 *dx = cpuid_leaf5_edx_val;
338 case CPUID_THERM_POWER_LEAF:
339 /* Disabling APERFMPERF for kernel usage */
340 maskecx = ~(1 << APERFMPERF_PRESENT);
344 /* Suppress extended topology stuff */
349 asm(XEN_EMULATE_PREFIX "cpuid"
354 : "0" (*ax), "2" (*cx));
361 STACK_FRAME_NON_STANDARD(xen_cpuid); /* XEN_EMULATE_PREFIX */
363 static bool __init xen_check_mwait(void)
366 struct xen_platform_op op = {
367 .cmd = XENPF_set_processor_pminfo,
368 .u.set_pminfo.id = -1,
369 .u.set_pminfo.type = XEN_PM_PDC,
372 unsigned int ax, bx, cx, dx;
373 unsigned int mwait_mask;
375 /* We need to determine whether it is OK to expose the MWAIT
376 * capability to the kernel to harvest deeper than C3 states from ACPI
377 * _CST using the processor_harvest_xen.c module. For this to work, we
378 * need to gather the MWAIT_LEAF values (which the cstate.c code
379 * checks against). The hypervisor won't expose the MWAIT flag because
380 * it would break backwards compatibility; so we will find out directly
381 * from the hardware and hypercall.
383 if (!xen_initial_domain())
387 * When running under platform earlier than Xen4.2, do not expose
388 * mwait, to avoid the risk of loading native acpi pad driver
390 if (!xen_running_on_version_or_later(4, 2))
396 native_cpuid(&ax, &bx, &cx, &dx);
398 mwait_mask = (1 << (X86_FEATURE_EST % 32)) |
399 (1 << (X86_FEATURE_MWAIT % 32));
401 if ((cx & mwait_mask) != mwait_mask)
404 /* We need to emulate the MWAIT_LEAF and for that we need both
405 * ecx and edx. The hypercall provides only partial information.
408 ax = CPUID_MWAIT_LEAF;
413 native_cpuid(&ax, &bx, &cx, &dx);
415 /* Ask the Hypervisor whether to clear ACPI_PDC_C_C2C3_FFH. If so,
416 * don't expose MWAIT_LEAF and let ACPI pick the IOPORT version of C3.
418 buf[0] = ACPI_PDC_REVISION_ID;
420 buf[2] = (ACPI_PDC_C_CAPABILITY_SMP | ACPI_PDC_EST_CAPABILITY_SWSMP);
422 set_xen_guest_handle(op.u.set_pminfo.pdc, buf);
424 if ((HYPERVISOR_platform_op(&op) == 0) &&
425 (buf[2] & (ACPI_PDC_C_C1_FFH | ACPI_PDC_C_C2C3_FFH))) {
426 cpuid_leaf5_ecx_val = cx;
427 cpuid_leaf5_edx_val = dx;
434 static void __init xen_init_cpuid_mask(void)
436 unsigned int ax, bx, cx, dx;
437 unsigned int xsave_mask;
439 cpuid_leaf1_edx_mask =
440 ~((1 << X86_FEATURE_MTRR) | /* disable MTRR */
441 (1 << X86_FEATURE_ACC)); /* thermal monitoring */
443 if (!xen_initial_domain())
444 cpuid_leaf1_edx_mask &=
445 ~((1 << X86_FEATURE_ACPI)); /* disable ACPI */
447 cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_X2APIC % 32));
451 cpuid(1, &ax, &bx, &cx, &dx);
454 (1 << (X86_FEATURE_XSAVE % 32)) |
455 (1 << (X86_FEATURE_OSXSAVE % 32));
457 /* Xen will set CR4.OSXSAVE if supported and not disabled by force */
458 if ((cx & xsave_mask) != xsave_mask)
459 cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */
460 if (xen_check_mwait())
461 cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32));
464 static void xen_set_debugreg(int reg, unsigned long val)
466 HYPERVISOR_set_debugreg(reg, val);
469 static unsigned long xen_get_debugreg(int reg)
471 return HYPERVISOR_get_debugreg(reg);
474 static void xen_end_context_switch(struct task_struct *next)
477 paravirt_end_context_switch(next);
480 static unsigned long xen_store_tr(void)
486 * Set the page permissions for a particular virtual address. If the
487 * address is a vmalloc mapping (or other non-linear mapping), then
488 * find the linear mapping of the page and also set its protections to
491 static void set_aliased_prot(void *v, pgprot_t prot)
500 ptep = lookup_address((unsigned long)v, &level);
501 BUG_ON(ptep == NULL);
503 pfn = pte_pfn(*ptep);
504 page = pfn_to_page(pfn);
506 pte = pfn_pte(pfn, prot);
509 * Careful: update_va_mapping() will fail if the virtual address
510 * we're poking isn't populated in the page tables. We don't
511 * need to worry about the direct map (that's always in the page
512 * tables), but we need to be careful about vmap space. In
513 * particular, the top level page table can lazily propagate
514 * entries between processes, so if we've switched mms since we
515 * vmapped the target in the first place, we might not have the
516 * top-level page table entry populated.
518 * We disable preemption because we want the same mm active when
519 * we probe the target and when we issue the hypercall. We'll
520 * have the same nominal mm, but if we're a kernel thread, lazy
521 * mm dropping could change our pgd.
523 * Out of an abundance of caution, this uses __get_user() to fault
524 * in the target address just in case there's some obscure case
525 * in which the target address isn't readable.
530 probe_kernel_read(&dummy, v, 1);
532 if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
535 if (!PageHighMem(page)) {
536 void *av = __va(PFN_PHYS(pfn));
539 if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
547 static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
549 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
553 * We need to mark the all aliases of the LDT pages RO. We
554 * don't need to call vm_flush_aliases(), though, since that's
555 * only responsible for flushing aliases out the TLBs, not the
556 * page tables, and Xen will flush the TLB for us if needed.
558 * To avoid confusing future readers: none of this is necessary
559 * to load the LDT. The hypervisor only checks this when the
560 * LDT is faulted in due to subsequent descriptor access.
563 for(i = 0; i < entries; i += entries_per_page)
564 set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
567 static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
569 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
572 for(i = 0; i < entries; i += entries_per_page)
573 set_aliased_prot(ldt + i, PAGE_KERNEL);
576 static void xen_set_ldt(const void *addr, unsigned entries)
578 struct mmuext_op *op;
579 struct multicall_space mcs = xen_mc_entry(sizeof(*op));
581 trace_xen_cpu_set_ldt(addr, entries);
584 op->cmd = MMUEXT_SET_LDT;
585 op->arg1.linear_addr = (unsigned long)addr;
586 op->arg2.nr_ents = entries;
588 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
590 xen_mc_issue(PARAVIRT_LAZY_CPU);
593 static void xen_load_gdt(const struct desc_ptr *dtr)
595 unsigned long va = dtr->address;
596 unsigned int size = dtr->size + 1;
597 unsigned pages = DIV_ROUND_UP(size, PAGE_SIZE);
598 unsigned long frames[pages];
602 * A GDT can be up to 64k in size, which corresponds to 8192
603 * 8-byte entries, or 16 4k pages..
606 BUG_ON(size > 65536);
607 BUG_ON(va & ~PAGE_MASK);
609 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
612 unsigned long pfn, mfn;
616 * The GDT is per-cpu and is in the percpu data area.
617 * That can be virtually mapped, so we need to do a
618 * page-walk to get the underlying MFN for the
619 * hypercall. The page can also be in the kernel's
620 * linear range, so we need to RO that mapping too.
622 ptep = lookup_address(va, &level);
623 BUG_ON(ptep == NULL);
625 pfn = pte_pfn(*ptep);
626 mfn = pfn_to_mfn(pfn);
627 virt = __va(PFN_PHYS(pfn));
631 make_lowmem_page_readonly((void *)va);
632 make_lowmem_page_readonly(virt);
635 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
640 * load_gdt for early boot, when the gdt is only mapped once
642 static void __init xen_load_gdt_boot(const struct desc_ptr *dtr)
644 unsigned long va = dtr->address;
645 unsigned int size = dtr->size + 1;
646 unsigned pages = DIV_ROUND_UP(size, PAGE_SIZE);
647 unsigned long frames[pages];
651 * A GDT can be up to 64k in size, which corresponds to 8192
652 * 8-byte entries, or 16 4k pages..
655 BUG_ON(size > 65536);
656 BUG_ON(va & ~PAGE_MASK);
658 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
660 unsigned long pfn, mfn;
662 pfn = virt_to_pfn(va);
663 mfn = pfn_to_mfn(pfn);
665 pte = pfn_pte(pfn, PAGE_KERNEL_RO);
667 if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0))
673 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
677 static inline bool desc_equal(const struct desc_struct *d1,
678 const struct desc_struct *d2)
680 return d1->a == d2->a && d1->b == d2->b;
683 static void load_TLS_descriptor(struct thread_struct *t,
684 unsigned int cpu, unsigned int i)
686 struct desc_struct *shadow = &per_cpu(shadow_tls_desc, cpu).desc[i];
687 struct desc_struct *gdt;
689 struct multicall_space mc;
691 if (desc_equal(shadow, &t->tls_array[i]))
694 *shadow = t->tls_array[i];
696 gdt = get_cpu_gdt_table(cpu);
697 maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
698 mc = __xen_mc_entry(0);
700 MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
703 static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
706 * XXX sleazy hack: If we're being called in a lazy-cpu zone
707 * and lazy gs handling is enabled, it means we're in a
708 * context switch, and %gs has just been saved. This means we
709 * can zero it out to prevent faults on exit from the
710 * hypervisor if the next process has no %gs. Either way, it
711 * has been saved, and the new value will get loaded properly.
712 * This will go away as soon as Xen has been modified to not
713 * save/restore %gs for normal hypercalls.
715 * On x86_64, this hack is not used for %gs, because gs points
716 * to KERNEL_GS_BASE (and uses it for PDA references), so we
717 * must not zero %gs on x86_64
719 * For x86_64, we need to zero %fs, otherwise we may get an
720 * exception between the new %fs descriptor being loaded and
721 * %fs being effectively cleared at __switch_to().
723 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
733 load_TLS_descriptor(t, cpu, 0);
734 load_TLS_descriptor(t, cpu, 1);
735 load_TLS_descriptor(t, cpu, 2);
737 xen_mc_issue(PARAVIRT_LAZY_CPU);
741 static void xen_load_gs_index(unsigned int idx)
743 if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
748 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
751 xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
752 u64 entry = *(u64 *)ptr;
754 trace_xen_cpu_write_ldt_entry(dt, entrynum, entry);
759 if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
765 static int cvt_gate_to_trap(int vector, const gate_desc *val,
766 struct trap_info *info)
770 if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT)
773 info->vector = vector;
775 addr = gate_offset(*val);
778 * Look for known traps using IST, and substitute them
779 * appropriately. The debugger ones are the only ones we care
780 * about. Xen will handle faults like double_fault,
781 * so we should never see them. Warn if
782 * there's an unexpected IST-using fault handler.
784 if (addr == (unsigned long)debug)
785 addr = (unsigned long)xen_debug;
786 else if (addr == (unsigned long)int3)
787 addr = (unsigned long)xen_int3;
788 else if (addr == (unsigned long)stack_segment)
789 addr = (unsigned long)xen_stack_segment;
790 else if (addr == (unsigned long)double_fault) {
791 /* Don't need to handle these */
793 #ifdef CONFIG_X86_MCE
794 } else if (addr == (unsigned long)machine_check) {
796 * when xen hypervisor inject vMCE to guest,
797 * use native mce handler to handle it
801 } else if (addr == (unsigned long)nmi)
803 * Use the native version as well.
807 /* Some other trap using IST? */
808 if (WARN_ON(val->ist != 0))
811 #endif /* CONFIG_X86_64 */
812 info->address = addr;
814 info->cs = gate_segment(*val);
815 info->flags = val->dpl;
816 /* interrupt gates clear IF */
817 if (val->type == GATE_INTERRUPT)
818 info->flags |= 1 << 2;
823 /* Locations of each CPU's IDT */
824 static DEFINE_PER_CPU(struct desc_ptr, idt_desc);
826 /* Set an IDT entry. If the entry is part of the current IDT, then
828 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
830 unsigned long p = (unsigned long)&dt[entrynum];
831 unsigned long start, end;
833 trace_xen_cpu_write_idt_entry(dt, entrynum, g);
837 start = __this_cpu_read(idt_desc.address);
838 end = start + __this_cpu_read(idt_desc.size) + 1;
842 native_write_idt_entry(dt, entrynum, g);
844 if (p >= start && (p + 8) <= end) {
845 struct trap_info info[2];
849 if (cvt_gate_to_trap(entrynum, g, &info[0]))
850 if (HYPERVISOR_set_trap_table(info))
857 static void xen_convert_trap_info(const struct desc_ptr *desc,
858 struct trap_info *traps)
860 unsigned in, out, count;
862 count = (desc->size+1) / sizeof(gate_desc);
865 for (in = out = 0; in < count; in++) {
866 gate_desc *entry = (gate_desc*)(desc->address) + in;
868 if (cvt_gate_to_trap(in, entry, &traps[out]))
871 traps[out].address = 0;
874 void xen_copy_trap_info(struct trap_info *traps)
876 const struct desc_ptr *desc = this_cpu_ptr(&idt_desc);
878 xen_convert_trap_info(desc, traps);
881 /* Load a new IDT into Xen. In principle this can be per-CPU, so we
882 hold a spinlock to protect the static traps[] array (static because
883 it avoids allocation, and saves stack space). */
884 static void xen_load_idt(const struct desc_ptr *desc)
886 static DEFINE_SPINLOCK(lock);
887 static struct trap_info traps[257];
889 trace_xen_cpu_load_idt(desc);
893 memcpy(this_cpu_ptr(&idt_desc), desc, sizeof(idt_desc));
895 xen_convert_trap_info(desc, traps);
898 if (HYPERVISOR_set_trap_table(traps))
904 /* Write a GDT descriptor entry. Ignore LDT descriptors, since
905 they're handled differently. */
906 static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
907 const void *desc, int type)
909 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
920 xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]);
923 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
933 * Version of write_gdt_entry for use at early boot-time needed to
934 * update an entry as simply as possible.
936 static void __init xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
937 const void *desc, int type)
939 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
948 xmaddr_t maddr = virt_to_machine(&dt[entry]);
950 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
951 dt[entry] = *(struct desc_struct *)desc;
957 static void xen_load_sp0(struct tss_struct *tss,
958 struct thread_struct *thread)
960 struct multicall_space mcs;
962 mcs = xen_mc_entry(0);
963 MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
964 xen_mc_issue(PARAVIRT_LAZY_CPU);
965 tss->x86_tss.sp0 = thread->sp0;
968 void xen_set_iopl_mask(unsigned mask)
970 struct physdev_set_iopl set_iopl;
972 /* Force the change at ring 0. */
973 set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
974 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
977 static void xen_io_delay(void)
981 static void xen_clts(void)
983 struct multicall_space mcs;
985 mcs = xen_mc_entry(0);
987 MULTI_fpu_taskswitch(mcs.mc, 0);
989 xen_mc_issue(PARAVIRT_LAZY_CPU);
992 static DEFINE_PER_CPU(unsigned long, xen_cr0_value);
994 static unsigned long xen_read_cr0(void)
996 unsigned long cr0 = this_cpu_read(xen_cr0_value);
998 if (unlikely(cr0 == 0)) {
999 cr0 = native_read_cr0();
1000 this_cpu_write(xen_cr0_value, cr0);
1006 static void xen_write_cr0(unsigned long cr0)
1008 struct multicall_space mcs;
1010 this_cpu_write(xen_cr0_value, cr0);
1012 /* Only pay attention to cr0.TS; everything else is
1014 mcs = xen_mc_entry(0);
1016 MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
1018 xen_mc_issue(PARAVIRT_LAZY_CPU);
1021 static void xen_write_cr4(unsigned long cr4)
1023 cr4 &= ~(X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PCE);
1025 native_write_cr4(cr4);
1027 #ifdef CONFIG_X86_64
1028 static inline unsigned long xen_read_cr8(void)
1032 static inline void xen_write_cr8(unsigned long val)
1038 static u64 xen_read_msr_safe(unsigned int msr, int *err)
1042 if (pmu_msr_read(msr, &val, err))
1045 val = native_read_msr_safe(msr, err);
1047 case MSR_IA32_APICBASE:
1048 #ifdef CONFIG_X86_X2APIC
1049 if (!(cpuid_ecx(1) & (1 << (X86_FEATURE_X2APIC & 31))))
1051 val &= ~X2APIC_ENABLE;
1057 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
1064 #ifdef CONFIG_X86_64
1068 case MSR_FS_BASE: which = SEGBASE_FS; goto set;
1069 case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set;
1070 case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set;
1073 base = ((u64)high << 32) | low;
1074 if (HYPERVISOR_set_segment_base(which, base) != 0)
1082 case MSR_SYSCALL_MASK:
1083 case MSR_IA32_SYSENTER_CS:
1084 case MSR_IA32_SYSENTER_ESP:
1085 case MSR_IA32_SYSENTER_EIP:
1086 /* Fast syscall setup is all done in hypercalls, so
1087 these are all ignored. Stub them out here to stop
1088 Xen console noise. */
1092 if (!pmu_msr_write(msr, low, high, &ret))
1093 ret = native_write_msr_safe(msr, low, high);
1099 static u64 xen_read_msr(unsigned int msr)
1102 * This will silently swallow a #GP from RDMSR. It may be worth
1107 return xen_read_msr_safe(msr, &err);
1110 static void xen_write_msr(unsigned int msr, unsigned low, unsigned high)
1113 * This will silently swallow a #GP from WRMSR. It may be worth
1116 xen_write_msr_safe(msr, low, high);
1119 void xen_setup_shared_info(void)
1121 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1122 set_fixmap(FIX_PARAVIRT_BOOTMAP,
1123 xen_start_info->shared_info);
1125 HYPERVISOR_shared_info =
1126 (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
1128 HYPERVISOR_shared_info =
1129 (struct shared_info *)__va(xen_start_info->shared_info);
1132 /* In UP this is as good a place as any to set up shared info */
1133 xen_setup_vcpu_info_placement();
1136 xen_setup_mfn_list_list();
1139 /* This is called once we have the cpu_possible_mask */
1140 void xen_setup_vcpu_info_placement(void)
1144 for_each_possible_cpu(cpu) {
1145 /* Set up direct vCPU id mapping for PV guests. */
1146 per_cpu(xen_vcpu_id, cpu) = cpu;
1147 xen_vcpu_setup(cpu);
1150 /* xen_vcpu_setup managed to place the vcpu_info within the
1151 * percpu area for all cpus, so make use of it. Note that for
1152 * PVH we want to use native IRQ mechanism. */
1153 if (have_vcpu_info_placement && !xen_pvh_domain()) {
1154 pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
1155 pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct);
1156 pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
1157 pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
1158 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
1162 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
1163 unsigned long addr, unsigned len)
1165 char *start, *end, *reloc;
1168 start = end = reloc = NULL;
1170 #define SITE(op, x) \
1171 case PARAVIRT_PATCH(op.x): \
1172 if (have_vcpu_info_placement) { \
1173 start = (char *)xen_##x##_direct; \
1174 end = xen_##x##_direct_end; \
1175 reloc = xen_##x##_direct_reloc; \
1180 SITE(pv_irq_ops, irq_enable);
1181 SITE(pv_irq_ops, irq_disable);
1182 SITE(pv_irq_ops, save_fl);
1183 SITE(pv_irq_ops, restore_fl);
1187 if (start == NULL || (end-start) > len)
1190 ret = paravirt_patch_insns(insnbuf, len, start, end);
1192 /* Note: because reloc is assigned from something that
1193 appears to be an array, gcc assumes it's non-null,
1194 but doesn't know its relationship with start and
1196 if (reloc > start && reloc < end) {
1197 int reloc_off = reloc - start;
1198 long *relocp = (long *)(insnbuf + reloc_off);
1199 long delta = start - (char *)addr;
1207 ret = paravirt_patch_default(type, clobbers, insnbuf,
1215 static const struct pv_info xen_info __initconst = {
1216 .shared_kernel_pmd = 0,
1218 #ifdef CONFIG_X86_64
1219 .extra_user_64bit_cs = FLAT_USER_CS64,
1224 static const struct pv_init_ops xen_init_ops __initconst = {
1228 static const struct pv_cpu_ops xen_cpu_ops __initconst = {
1231 .set_debugreg = xen_set_debugreg,
1232 .get_debugreg = xen_get_debugreg,
1236 .read_cr0 = xen_read_cr0,
1237 .write_cr0 = xen_write_cr0,
1239 .read_cr4 = native_read_cr4,
1240 .read_cr4_safe = native_read_cr4_safe,
1241 .write_cr4 = xen_write_cr4,
1243 #ifdef CONFIG_X86_64
1244 .read_cr8 = xen_read_cr8,
1245 .write_cr8 = xen_write_cr8,
1248 .wbinvd = native_wbinvd,
1250 .read_msr = xen_read_msr,
1251 .write_msr = xen_write_msr,
1253 .read_msr_safe = xen_read_msr_safe,
1254 .write_msr_safe = xen_write_msr_safe,
1256 .read_pmc = xen_read_pmc,
1259 #ifdef CONFIG_X86_64
1260 .usergs_sysret64 = xen_sysret64,
1263 .load_tr_desc = paravirt_nop,
1264 .set_ldt = xen_set_ldt,
1265 .load_gdt = xen_load_gdt,
1266 .load_idt = xen_load_idt,
1267 .load_tls = xen_load_tls,
1268 #ifdef CONFIG_X86_64
1269 .load_gs_index = xen_load_gs_index,
1272 .alloc_ldt = xen_alloc_ldt,
1273 .free_ldt = xen_free_ldt,
1275 .store_idt = native_store_idt,
1276 .store_tr = xen_store_tr,
1278 .write_ldt_entry = xen_write_ldt_entry,
1279 .write_gdt_entry = xen_write_gdt_entry,
1280 .write_idt_entry = xen_write_idt_entry,
1281 .load_sp0 = xen_load_sp0,
1283 .set_iopl_mask = xen_set_iopl_mask,
1284 .io_delay = xen_io_delay,
1286 /* Xen takes care of %gs when switching to usermode for us */
1287 .swapgs = paravirt_nop,
1289 .start_context_switch = paravirt_start_context_switch,
1290 .end_context_switch = xen_end_context_switch,
1293 static void xen_reboot(int reason)
1295 struct sched_shutdown r = { .reason = reason };
1298 for_each_online_cpu(cpu)
1299 xen_pmu_finish(cpu);
1301 if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
1305 static void xen_restart(char *msg)
1307 xen_reboot(SHUTDOWN_reboot);
1310 static void xen_emergency_restart(void)
1312 xen_reboot(SHUTDOWN_reboot);
1315 static void xen_machine_halt(void)
1317 xen_reboot(SHUTDOWN_poweroff);
1320 static void xen_machine_power_off(void)
1324 xen_reboot(SHUTDOWN_poweroff);
1327 static void xen_crash_shutdown(struct pt_regs *regs)
1329 xen_reboot(SHUTDOWN_crash);
1333 xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
1335 if (!kexec_crash_loaded())
1336 xen_reboot(SHUTDOWN_crash);
1340 static struct notifier_block xen_panic_block = {
1341 .notifier_call= xen_panic_event,
1345 int xen_panic_handler_init(void)
1347 atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block);
1351 static const struct machine_ops xen_machine_ops __initconst = {
1352 .restart = xen_restart,
1353 .halt = xen_machine_halt,
1354 .power_off = xen_machine_power_off,
1355 .shutdown = xen_machine_halt,
1356 .crash_shutdown = xen_crash_shutdown,
1357 .emergency_restart = xen_emergency_restart,
1360 static unsigned char xen_get_nmi_reason(void)
1362 unsigned char reason = 0;
1364 /* Construct a value which looks like it came from port 0x61. */
1365 if (test_bit(_XEN_NMIREASON_io_error,
1366 &HYPERVISOR_shared_info->arch.nmi_reason))
1367 reason |= NMI_REASON_IOCHK;
1368 if (test_bit(_XEN_NMIREASON_pci_serr,
1369 &HYPERVISOR_shared_info->arch.nmi_reason))
1370 reason |= NMI_REASON_SERR;
1375 static void __init xen_boot_params_init_edd(void)
1377 #if IS_ENABLED(CONFIG_EDD)
1378 struct xen_platform_op op;
1379 struct edd_info *edd_info;
1384 edd_info = boot_params.eddbuf;
1385 mbr_signature = boot_params.edd_mbr_sig_buffer;
1387 op.cmd = XENPF_firmware_info;
1389 op.u.firmware_info.type = XEN_FW_DISK_INFO;
1390 for (nr = 0; nr < EDDMAXNR; nr++) {
1391 struct edd_info *info = edd_info + nr;
1393 op.u.firmware_info.index = nr;
1394 info->params.length = sizeof(info->params);
1395 set_xen_guest_handle(op.u.firmware_info.u.disk_info.edd_params,
1397 ret = HYPERVISOR_platform_op(&op);
1401 #define C(x) info->x = op.u.firmware_info.u.disk_info.x
1404 C(interface_support);
1405 C(legacy_max_cylinder);
1407 C(legacy_sectors_per_track);
1410 boot_params.eddbuf_entries = nr;
1412 op.u.firmware_info.type = XEN_FW_DISK_MBR_SIGNATURE;
1413 for (nr = 0; nr < EDD_MBR_SIG_MAX; nr++) {
1414 op.u.firmware_info.index = nr;
1415 ret = HYPERVISOR_platform_op(&op);
1418 mbr_signature[nr] = op.u.firmware_info.u.disk_mbr_signature.mbr_signature;
1420 boot_params.edd_mbr_sig_buf_entries = nr;
1425 * Set up the GDT and segment registers for -fstack-protector. Until
1426 * we do this, we have to be careful not to call any stack-protected
1427 * function, which is most of the kernel.
1429 * Note, that it is __ref because the only caller of this after init
1430 * is PVH which is not going to use xen_load_gdt_boot or other
1433 static void __ref xen_setup_gdt(int cpu)
1435 if (xen_feature(XENFEAT_auto_translated_physmap)) {
1436 #ifdef CONFIG_X86_64
1437 unsigned long dummy;
1439 load_percpu_segment(cpu); /* We need to access per-cpu area */
1440 switch_to_new_gdt(cpu); /* GDT and GS set */
1442 /* We are switching of the Xen provided GDT to our HVM mode
1443 * GDT. The new GDT has __KERNEL_CS with CS.L = 1
1444 * and we are jumping to reload it.
1446 asm volatile ("pushq %0\n"
1447 "leaq 1f(%%rip),%0\n"
1451 : "=&r" (dummy) : "0" (__KERNEL_CS));
1454 * While not needed, we also set the %es, %ds, and %fs
1455 * to zero. We don't care about %ss as it is NULL.
1456 * Strictly speaking this is not needed as Xen zeros those
1457 * out (and also MSR_FS_BASE, MSR_GS_BASE, MSR_KERNEL_GS_BASE)
1459 * Linux zeros them in cpu_init() and in secondary_startup_64
1466 /* PVH: TODO Implement. */
1469 return; /* PVH does not need any PV GDT ops. */
1471 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
1472 pv_cpu_ops.load_gdt = xen_load_gdt_boot;
1474 setup_stack_canary_segment(0);
1475 switch_to_new_gdt(0);
1477 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry;
1478 pv_cpu_ops.load_gdt = xen_load_gdt;
1481 #ifdef CONFIG_XEN_PVH
1483 * A PV guest starts with default flags that are not set for PVH, set them
1486 static void xen_pvh_set_cr_flags(int cpu)
1489 /* Some of these are setup in 'secondary_startup_64'. The others:
1490 * X86_CR0_TS, X86_CR0_PE, X86_CR0_ET are set by Xen for HVM guests
1491 * (which PVH shared codepaths), while X86_CR0_PG is for PVH. */
1492 write_cr0(read_cr0() | X86_CR0_MP | X86_CR0_NE | X86_CR0_WP | X86_CR0_AM);
1497 * For BSP, PSE PGE are set in probe_page_size_mask(), for APs
1498 * set them here. For all, OSFXSR OSXMMEXCPT are set in fpu__init_cpu().
1500 if (boot_cpu_has(X86_FEATURE_PSE))
1501 cr4_set_bits_and_update_boot(X86_CR4_PSE);
1503 if (boot_cpu_has(X86_FEATURE_PGE))
1504 cr4_set_bits_and_update_boot(X86_CR4_PGE);
1508 * Note, that it is ref - because the only caller of this after init
1509 * is PVH which is not going to use xen_load_gdt_boot or other
1512 void __ref xen_pvh_secondary_vcpu_init(int cpu)
1515 xen_pvh_set_cr_flags(cpu);
1518 static void __init xen_pvh_early_guest_init(void)
1520 if (!xen_feature(XENFEAT_auto_translated_physmap))
1523 if (!xen_feature(XENFEAT_hvm_callback_vector))
1526 xen_have_vector_callback = 1;
1528 xen_pvh_early_cpu_init(0, false);
1529 xen_pvh_set_cr_flags(0);
1531 #ifdef CONFIG_X86_32
1532 BUG(); /* PVH: Implement proper support. */
1535 #endif /* CONFIG_XEN_PVH */
1537 static void __init xen_dom0_set_legacy_features(void)
1539 x86_platform.legacy.rtc = 1;
1542 /* First C function to be called on Xen boot */
1543 asmlinkage __visible void __init xen_start_kernel(void)
1545 struct physdev_set_iopl set_iopl;
1546 unsigned long initrd_start = 0;
1549 if (!xen_start_info)
1552 xen_domain_type = XEN_PV_DOMAIN;
1554 xen_setup_features();
1555 #ifdef CONFIG_XEN_PVH
1556 xen_pvh_early_guest_init();
1558 xen_setup_machphys_mapping();
1560 /* Install Xen paravirt ops */
1562 pv_init_ops = xen_init_ops;
1563 if (!xen_pvh_domain()) {
1564 pv_cpu_ops = xen_cpu_ops;
1566 x86_platform.get_nmi_reason = xen_get_nmi_reason;
1569 if (xen_feature(XENFEAT_auto_translated_physmap))
1570 x86_init.resources.memory_setup = xen_auto_xlated_memory_setup;
1572 x86_init.resources.memory_setup = xen_memory_setup;
1573 x86_init.oem.arch_setup = xen_arch_setup;
1574 x86_init.oem.banner = xen_banner;
1576 xen_init_time_ops();
1579 * Set up some pagetable state before starting to set any ptes.
1584 /* Prevent unwanted bits from being set in PTEs. */
1585 __supported_pte_mask &= ~_PAGE_GLOBAL;
1588 * Prevent page tables from being allocated in highmem, even
1589 * if CONFIG_HIGHPTE is enabled.
1591 __userpte_alloc_gfp &= ~__GFP_HIGHMEM;
1593 /* Work out if we support NX */
1597 xen_build_dynamic_phys_to_machine();
1600 * Set up kernel GDT and segment registers, mainly so that
1601 * -fstack-protector code can be executed.
1606 xen_init_cpuid_mask();
1608 #ifdef CONFIG_X86_LOCAL_APIC
1610 * set up the basic apic ops.
1615 if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
1616 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
1617 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
1620 machine_ops = xen_machine_ops;
1623 * The only reliable way to retain the initial address of the
1624 * percpu gdt_page is to remember it here, so we can go and
1625 * mark it RW later, when the initial percpu area is freed.
1627 xen_initial_gdt = &per_cpu(gdt_page, 0);
1631 #ifdef CONFIG_ACPI_NUMA
1633 * The pages we from Xen are not related to machine pages, so
1634 * any NUMA information the kernel tries to get from ACPI will
1635 * be meaningless. Prevent it from trying.
1639 /* Don't do the full vcpu_info placement stuff until we have a
1640 possible map and a non-dummy shared_info. */
1641 per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1643 local_irq_disable();
1644 early_boot_irqs_disabled = true;
1646 xen_raw_console_write("mapping kernel into physical memory\n");
1647 xen_setup_kernel_pagetable((pgd_t *)xen_start_info->pt_base,
1648 xen_start_info->nr_pages);
1649 xen_reserve_special_pages();
1651 /* keep using Xen gdt for now; no urgent need to change it */
1653 #ifdef CONFIG_X86_32
1654 pv_info.kernel_rpl = 1;
1655 if (xen_feature(XENFEAT_supervisor_mode_kernel))
1656 pv_info.kernel_rpl = 0;
1658 pv_info.kernel_rpl = 0;
1660 /* set the limit of our address space */
1663 /* PVH: runs at default kernel iopl of 0 */
1664 if (!xen_pvh_domain()) {
1666 * We used to do this in xen_arch_setup, but that is too late
1667 * on AMD were early_cpu_init (run before ->arch_setup()) calls
1668 * early_amd_init which pokes 0xcf8 port.
1671 rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
1673 xen_raw_printk("physdev_op failed %d\n", rc);
1676 #ifdef CONFIG_X86_32
1677 /* set up basic CPUID stuff */
1678 cpu_detect(&new_cpu_data);
1679 set_cpu_cap(&new_cpu_data, X86_FEATURE_FPU);
1680 new_cpu_data.wp_works_ok = 1;
1681 new_cpu_data.x86_capability[CPUID_1_EDX] = cpuid_edx(1);
1684 if (xen_start_info->mod_start) {
1685 if (xen_start_info->flags & SIF_MOD_START_PFN)
1686 initrd_start = PFN_PHYS(xen_start_info->mod_start);
1688 initrd_start = __pa(xen_start_info->mod_start);
1691 /* Poke various useful things into boot_params */
1692 boot_params.hdr.type_of_loader = (9 << 4) | 0;
1693 boot_params.hdr.ramdisk_image = initrd_start;
1694 boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
1695 boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
1696 boot_params.hdr.hardware_subarch = X86_SUBARCH_XEN;
1698 if (!xen_initial_domain()) {
1699 add_preferred_console("xenboot", 0, NULL);
1700 add_preferred_console("tty", 0, NULL);
1701 add_preferred_console("hvc", 0, NULL);
1703 x86_init.pci.arch_init = pci_xen_init;
1705 const struct dom0_vga_console_info *info =
1706 (void *)((char *)xen_start_info +
1707 xen_start_info->console.dom0.info_off);
1708 struct xen_platform_op op = {
1709 .cmd = XENPF_firmware_info,
1710 .interface_version = XENPF_INTERFACE_VERSION,
1711 .u.firmware_info.type = XEN_FW_KBD_SHIFT_FLAGS,
1714 x86_platform.set_legacy_features =
1715 xen_dom0_set_legacy_features;
1716 xen_init_vga(info, xen_start_info->console.dom0.info_size);
1717 xen_start_info->console.domU.mfn = 0;
1718 xen_start_info->console.domU.evtchn = 0;
1720 if (HYPERVISOR_platform_op(&op) == 0)
1721 boot_params.kbd_status = op.u.firmware_info.u.kbd_shift_flags;
1723 /* Make sure ACS will be enabled */
1726 xen_acpi_sleep_register();
1728 /* Avoid searching for BIOS MP tables */
1729 x86_init.mpparse.find_smp_config = x86_init_noop;
1730 x86_init.mpparse.get_smp_config = x86_init_uint_noop;
1732 xen_boot_params_init_edd();
1735 /* PCI BIOS service won't work from a PV guest. */
1736 pci_probe &= ~PCI_PROBE_BIOS;
1738 xen_raw_console_write("about to get started...\n");
1740 /* Let's presume PV guests always boot on vCPU with id 0. */
1741 per_cpu(xen_vcpu_id, 0) = 0;
1743 xen_setup_runstate_info(0);
1747 /* Start the world */
1748 #ifdef CONFIG_X86_32
1749 i386_start_kernel();
1751 cr4_init_shadow(); /* 32b kernel does this in i386_start_kernel() */
1752 x86_64_start_reservations((char *)__pa_symbol(&boot_params));
1756 void __ref xen_hvm_init_shared_info(void)
1759 struct xen_add_to_physmap xatp;
1760 static struct shared_info *shared_info_page = 0;
1762 if (!shared_info_page)
1763 shared_info_page = (struct shared_info *)
1764 extend_brk(PAGE_SIZE, PAGE_SIZE);
1765 xatp.domid = DOMID_SELF;
1767 xatp.space = XENMAPSPACE_shared_info;
1768 xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
1769 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
1772 HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
1774 /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
1775 * page, we use it in the event channel upcall and in some pvclock
1776 * related functions. We don't need the vcpu_info placement
1777 * optimizations because we don't use any pv_mmu or pv_irq op on
1779 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
1780 * online but xen_hvm_init_shared_info is run at resume time too and
1781 * in that case multiple vcpus might be online. */
1782 for_each_online_cpu(cpu) {
1783 /* Leave it to be NULL. */
1784 if (xen_vcpu_nr(cpu) >= MAX_VIRT_CPUS)
1786 per_cpu(xen_vcpu, cpu) =
1787 &HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
1791 #ifdef CONFIG_XEN_PVHVM
1792 static void __init init_hvm_pv_info(void)
1795 uint32_t eax, ebx, ecx, edx, pages, msr, base;
1798 base = xen_cpuid_base();
1799 cpuid(base + 1, &eax, &ebx, &ecx, &edx);
1802 minor = eax & 0xffff;
1803 printk(KERN_INFO "Xen version %d.%d.\n", major, minor);
1805 cpuid(base + 2, &pages, &msr, &ecx, &edx);
1807 pfn = __pa(hypercall_page);
1808 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
1810 xen_setup_features();
1812 cpuid(base + 4, &eax, &ebx, &ecx, &edx);
1813 if (eax & XEN_HVM_CPUID_VCPU_ID_PRESENT)
1814 this_cpu_write(xen_vcpu_id, ebx);
1816 this_cpu_write(xen_vcpu_id, smp_processor_id());
1818 pv_info.name = "Xen HVM";
1820 xen_domain_type = XEN_HVM_DOMAIN;
1823 static int xen_hvm_cpu_notify(struct notifier_block *self, unsigned long action,
1826 int cpu = (long)hcpu;
1828 case CPU_UP_PREPARE:
1829 if (cpu_acpi_id(cpu) != U32_MAX)
1830 per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);
1832 per_cpu(xen_vcpu_id, cpu) = cpu;
1833 xen_vcpu_setup(cpu);
1834 if (xen_have_vector_callback) {
1835 if (xen_feature(XENFEAT_hvm_safe_pvclock))
1836 xen_setup_timer(cpu);
1845 static struct notifier_block xen_hvm_cpu_notifier = {
1846 .notifier_call = xen_hvm_cpu_notify,
1849 #ifdef CONFIG_KEXEC_CORE
1850 static void xen_hvm_shutdown(void)
1852 native_machine_shutdown();
1853 if (kexec_in_progress)
1854 xen_reboot(SHUTDOWN_soft_reset);
1857 static void xen_hvm_crash_shutdown(struct pt_regs *regs)
1859 native_machine_crash_shutdown(regs);
1860 xen_reboot(SHUTDOWN_soft_reset);
1864 static void __init xen_hvm_guest_init(void)
1866 if (xen_pv_domain())
1871 xen_hvm_init_shared_info();
1873 xen_panic_handler_init();
1875 if (xen_feature(XENFEAT_hvm_callback_vector))
1876 xen_have_vector_callback = 1;
1878 register_cpu_notifier(&xen_hvm_cpu_notifier);
1879 xen_unplug_emulated_devices();
1880 x86_init.irqs.intr_init = xen_init_IRQ;
1881 xen_hvm_init_time_ops();
1882 xen_hvm_init_mmu_ops();
1883 #ifdef CONFIG_KEXEC_CORE
1884 machine_ops.shutdown = xen_hvm_shutdown;
1885 machine_ops.crash_shutdown = xen_hvm_crash_shutdown;
1890 static bool xen_nopv = false;
1891 static __init int xen_parse_nopv(char *arg)
1896 early_param("xen_nopv", xen_parse_nopv);
1898 static uint32_t __init xen_platform(void)
1903 return xen_cpuid_base();
1906 bool xen_hvm_need_lapic(void)
1910 if (xen_pv_domain())
1912 if (!xen_hvm_domain())
1914 if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
1918 EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
1920 static void xen_set_cpu_features(struct cpuinfo_x86 *c)
1922 if (xen_pv_domain()) {
1923 clear_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
1924 set_cpu_cap(c, X86_FEATURE_XENPV);
1928 const struct hypervisor_x86 x86_hyper_xen = {
1930 .detect = xen_platform,
1931 #ifdef CONFIG_XEN_PVHVM
1932 .init_platform = xen_hvm_guest_init,
1934 .x2apic_available = xen_x2apic_para_available,
1935 .set_cpu_features = xen_set_cpu_features,
1937 EXPORT_SYMBOL(x86_hyper_xen);
1939 #ifdef CONFIG_HOTPLUG_CPU
1940 void xen_arch_register_cpu(int num)
1942 arch_register_cpu(num);
1944 EXPORT_SYMBOL(xen_arch_register_cpu);
1946 void xen_arch_unregister_cpu(int num)
1948 arch_unregister_cpu(num);
1950 EXPORT_SYMBOL(xen_arch_unregister_cpu);