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(uint32_t, xen_vcpu_id);
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);
141 static int xen_cpu_up_prepare(unsigned int cpu);
142 static int xen_cpu_up_online(unsigned int cpu);
143 static int xen_cpu_dead(unsigned int cpu);
146 * Point at some empty memory to start with. We map the real shared_info
147 * page as soon as fixmap is up and running.
149 struct shared_info *HYPERVISOR_shared_info = &xen_dummy_shared_info;
152 * Flag to determine whether vcpu info placement is available on all
153 * VCPUs. We assume it is to start with, and then set it to zero on
154 * the first failure. This is because it can succeed on some VCPUs
155 * and not others, since it can involve hypervisor memory allocation,
156 * or because the guest failed to guarantee all the appropriate
157 * constraints on all VCPUs (ie buffer can't cross a page boundary).
159 * Note that any particular CPU may be using a placed vcpu structure,
160 * but we can only optimise if the all are.
162 * 0: not available, 1: available
164 static int have_vcpu_info_placement = 1;
167 struct desc_struct desc[3];
171 * Updating the 3 TLS descriptors in the GDT on every task switch is
172 * surprisingly expensive so we avoid updating them if they haven't
173 * changed. Since Xen writes different descriptors than the one
174 * passed in the update_descriptor hypercall we keep shadow copies to
177 static DEFINE_PER_CPU(struct tls_descs, shadow_tls_desc);
179 static void clamp_max_cpus(void)
182 if (setup_max_cpus > MAX_VIRT_CPUS)
183 setup_max_cpus = MAX_VIRT_CPUS;
187 void xen_vcpu_setup(int cpu)
189 struct vcpu_register_vcpu_info info;
191 struct vcpu_info *vcpup;
193 BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
196 * This path is called twice on PVHVM - first during bootup via
197 * smp_init -> xen_hvm_cpu_notify, and then if the VCPU is being
198 * hotplugged: cpu_up -> xen_hvm_cpu_notify.
199 * As we can only do the VCPUOP_register_vcpu_info once lets
200 * not over-write its result.
202 * For PV it is called during restore (xen_vcpu_restore) and bootup
203 * (xen_setup_vcpu_info_placement). The hotplug mechanism does not
206 if (xen_hvm_domain()) {
207 if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu))
210 if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS)
211 per_cpu(xen_vcpu, cpu) =
212 &HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
214 if (!have_vcpu_info_placement) {
215 if (cpu >= MAX_VIRT_CPUS)
220 vcpup = &per_cpu(xen_vcpu_info, cpu);
221 info.mfn = arbitrary_virt_to_mfn(vcpup);
222 info.offset = offset_in_page(vcpup);
224 /* Check to see if the hypervisor will put the vcpu_info
225 structure where we want it, which allows direct access via
227 N.B. This hypercall can _only_ be called once per CPU. Subsequent
228 calls will error out with -EINVAL. This is due to the fact that
229 hypervisor has no unregister variant and this hypercall does not
230 allow to over-write info.mfn and info.offset.
232 err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
236 printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
237 have_vcpu_info_placement = 0;
240 /* This cpu is using the registered vcpu info, even if
241 later ones fail to. */
242 per_cpu(xen_vcpu, cpu) = vcpup;
247 * On restore, set the vcpu placement up again.
248 * If it fails, then we're in a bad state, since
249 * we can't back out from using it...
251 void xen_vcpu_restore(void)
255 for_each_possible_cpu(cpu) {
256 bool other_cpu = (cpu != smp_processor_id());
257 bool is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up, xen_vcpu_nr(cpu),
260 if (other_cpu && is_up &&
261 HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(cpu), NULL))
264 xen_setup_runstate_info(cpu);
266 if (have_vcpu_info_placement)
269 if (other_cpu && is_up &&
270 HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL))
275 static void __init xen_banner(void)
277 unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
278 struct xen_extraversion extra;
279 HYPERVISOR_xen_version(XENVER_extraversion, &extra);
281 pr_info("Booting paravirtualized kernel %son %s\n",
282 xen_feature(XENFEAT_auto_translated_physmap) ?
283 "with PVH extensions " : "", pv_info.name);
284 printk(KERN_INFO "Xen version: %d.%d%s%s\n",
285 version >> 16, version & 0xffff, extra.extraversion,
286 xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
288 /* Check if running on Xen version (major, minor) or later */
290 xen_running_on_version_or_later(unsigned int major, unsigned int minor)
292 unsigned int version;
297 version = HYPERVISOR_xen_version(XENVER_version, NULL);
298 if ((((version >> 16) == major) && ((version & 0xffff) >= minor)) ||
299 ((version >> 16) > major))
304 #define CPUID_THERM_POWER_LEAF 6
305 #define APERFMPERF_PRESENT 0
307 static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
308 static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
310 static __read_mostly unsigned int cpuid_leaf1_ecx_set_mask;
311 static __read_mostly unsigned int cpuid_leaf5_ecx_val;
312 static __read_mostly unsigned int cpuid_leaf5_edx_val;
314 static void xen_cpuid(unsigned int *ax, unsigned int *bx,
315 unsigned int *cx, unsigned int *dx)
317 unsigned maskebx = ~0;
318 unsigned maskecx = ~0;
319 unsigned maskedx = ~0;
322 * Mask out inconvenient features, to try and disable as many
323 * unsupported kernel subsystems as possible.
327 maskecx = cpuid_leaf1_ecx_mask;
328 setecx = cpuid_leaf1_ecx_set_mask;
329 maskedx = cpuid_leaf1_edx_mask;
332 case CPUID_MWAIT_LEAF:
333 /* Synthesize the values.. */
336 *cx = cpuid_leaf5_ecx_val;
337 *dx = cpuid_leaf5_edx_val;
340 case CPUID_THERM_POWER_LEAF:
341 /* Disabling APERFMPERF for kernel usage */
342 maskecx = ~(1 << APERFMPERF_PRESENT);
346 /* Suppress extended topology stuff */
351 asm(XEN_EMULATE_PREFIX "cpuid"
356 : "0" (*ax), "2" (*cx));
363 STACK_FRAME_NON_STANDARD(xen_cpuid); /* XEN_EMULATE_PREFIX */
365 static bool __init xen_check_mwait(void)
368 struct xen_platform_op op = {
369 .cmd = XENPF_set_processor_pminfo,
370 .u.set_pminfo.id = -1,
371 .u.set_pminfo.type = XEN_PM_PDC,
374 unsigned int ax, bx, cx, dx;
375 unsigned int mwait_mask;
377 /* We need to determine whether it is OK to expose the MWAIT
378 * capability to the kernel to harvest deeper than C3 states from ACPI
379 * _CST using the processor_harvest_xen.c module. For this to work, we
380 * need to gather the MWAIT_LEAF values (which the cstate.c code
381 * checks against). The hypervisor won't expose the MWAIT flag because
382 * it would break backwards compatibility; so we will find out directly
383 * from the hardware and hypercall.
385 if (!xen_initial_domain())
389 * When running under platform earlier than Xen4.2, do not expose
390 * mwait, to avoid the risk of loading native acpi pad driver
392 if (!xen_running_on_version_or_later(4, 2))
398 native_cpuid(&ax, &bx, &cx, &dx);
400 mwait_mask = (1 << (X86_FEATURE_EST % 32)) |
401 (1 << (X86_FEATURE_MWAIT % 32));
403 if ((cx & mwait_mask) != mwait_mask)
406 /* We need to emulate the MWAIT_LEAF and for that we need both
407 * ecx and edx. The hypercall provides only partial information.
410 ax = CPUID_MWAIT_LEAF;
415 native_cpuid(&ax, &bx, &cx, &dx);
417 /* Ask the Hypervisor whether to clear ACPI_PDC_C_C2C3_FFH. If so,
418 * don't expose MWAIT_LEAF and let ACPI pick the IOPORT version of C3.
420 buf[0] = ACPI_PDC_REVISION_ID;
422 buf[2] = (ACPI_PDC_C_CAPABILITY_SMP | ACPI_PDC_EST_CAPABILITY_SWSMP);
424 set_xen_guest_handle(op.u.set_pminfo.pdc, buf);
426 if ((HYPERVISOR_platform_op(&op) == 0) &&
427 (buf[2] & (ACPI_PDC_C_C1_FFH | ACPI_PDC_C_C2C3_FFH))) {
428 cpuid_leaf5_ecx_val = cx;
429 cpuid_leaf5_edx_val = dx;
436 static void __init xen_init_cpuid_mask(void)
438 unsigned int ax, bx, cx, dx;
439 unsigned int xsave_mask;
441 cpuid_leaf1_edx_mask =
442 ~((1 << X86_FEATURE_MTRR) | /* disable MTRR */
443 (1 << X86_FEATURE_ACC)); /* thermal monitoring */
445 if (!xen_initial_domain())
446 cpuid_leaf1_edx_mask &=
447 ~((1 << X86_FEATURE_ACPI)); /* disable ACPI */
449 cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_X2APIC % 32));
453 cpuid(1, &ax, &bx, &cx, &dx);
456 (1 << (X86_FEATURE_XSAVE % 32)) |
457 (1 << (X86_FEATURE_OSXSAVE % 32));
459 /* Xen will set CR4.OSXSAVE if supported and not disabled by force */
460 if ((cx & xsave_mask) != xsave_mask)
461 cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */
462 if (xen_check_mwait())
463 cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32));
466 static void xen_set_debugreg(int reg, unsigned long val)
468 HYPERVISOR_set_debugreg(reg, val);
471 static unsigned long xen_get_debugreg(int reg)
473 return HYPERVISOR_get_debugreg(reg);
476 static void xen_end_context_switch(struct task_struct *next)
479 paravirt_end_context_switch(next);
482 static unsigned long xen_store_tr(void)
488 * Set the page permissions for a particular virtual address. If the
489 * address is a vmalloc mapping (or other non-linear mapping), then
490 * find the linear mapping of the page and also set its protections to
493 static void set_aliased_prot(void *v, pgprot_t prot)
502 ptep = lookup_address((unsigned long)v, &level);
503 BUG_ON(ptep == NULL);
505 pfn = pte_pfn(*ptep);
506 page = pfn_to_page(pfn);
508 pte = pfn_pte(pfn, prot);
511 * Careful: update_va_mapping() will fail if the virtual address
512 * we're poking isn't populated in the page tables. We don't
513 * need to worry about the direct map (that's always in the page
514 * tables), but we need to be careful about vmap space. In
515 * particular, the top level page table can lazily propagate
516 * entries between processes, so if we've switched mms since we
517 * vmapped the target in the first place, we might not have the
518 * top-level page table entry populated.
520 * We disable preemption because we want the same mm active when
521 * we probe the target and when we issue the hypercall. We'll
522 * have the same nominal mm, but if we're a kernel thread, lazy
523 * mm dropping could change our pgd.
525 * Out of an abundance of caution, this uses __get_user() to fault
526 * in the target address just in case there's some obscure case
527 * in which the target address isn't readable.
532 probe_kernel_read(&dummy, v, 1);
534 if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
537 if (!PageHighMem(page)) {
538 void *av = __va(PFN_PHYS(pfn));
541 if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
549 static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
551 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
555 * We need to mark the all aliases of the LDT pages RO. We
556 * don't need to call vm_flush_aliases(), though, since that's
557 * only responsible for flushing aliases out the TLBs, not the
558 * page tables, and Xen will flush the TLB for us if needed.
560 * To avoid confusing future readers: none of this is necessary
561 * to load the LDT. The hypervisor only checks this when the
562 * LDT is faulted in due to subsequent descriptor access.
565 for(i = 0; i < entries; i += entries_per_page)
566 set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
569 static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
571 const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
574 for(i = 0; i < entries; i += entries_per_page)
575 set_aliased_prot(ldt + i, PAGE_KERNEL);
578 static void xen_set_ldt(const void *addr, unsigned entries)
580 struct mmuext_op *op;
581 struct multicall_space mcs = xen_mc_entry(sizeof(*op));
583 trace_xen_cpu_set_ldt(addr, entries);
586 op->cmd = MMUEXT_SET_LDT;
587 op->arg1.linear_addr = (unsigned long)addr;
588 op->arg2.nr_ents = entries;
590 MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
592 xen_mc_issue(PARAVIRT_LAZY_CPU);
595 static void xen_load_gdt(const struct desc_ptr *dtr)
597 unsigned long va = dtr->address;
598 unsigned int size = dtr->size + 1;
599 unsigned pages = DIV_ROUND_UP(size, PAGE_SIZE);
600 unsigned long frames[pages];
604 * A GDT can be up to 64k in size, which corresponds to 8192
605 * 8-byte entries, or 16 4k pages..
608 BUG_ON(size > 65536);
609 BUG_ON(va & ~PAGE_MASK);
611 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
614 unsigned long pfn, mfn;
618 * The GDT is per-cpu and is in the percpu data area.
619 * That can be virtually mapped, so we need to do a
620 * page-walk to get the underlying MFN for the
621 * hypercall. The page can also be in the kernel's
622 * linear range, so we need to RO that mapping too.
624 ptep = lookup_address(va, &level);
625 BUG_ON(ptep == NULL);
627 pfn = pte_pfn(*ptep);
628 mfn = pfn_to_mfn(pfn);
629 virt = __va(PFN_PHYS(pfn));
633 make_lowmem_page_readonly((void *)va);
634 make_lowmem_page_readonly(virt);
637 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
642 * load_gdt for early boot, when the gdt is only mapped once
644 static void __init xen_load_gdt_boot(const struct desc_ptr *dtr)
646 unsigned long va = dtr->address;
647 unsigned int size = dtr->size + 1;
648 unsigned pages = DIV_ROUND_UP(size, PAGE_SIZE);
649 unsigned long frames[pages];
653 * A GDT can be up to 64k in size, which corresponds to 8192
654 * 8-byte entries, or 16 4k pages..
657 BUG_ON(size > 65536);
658 BUG_ON(va & ~PAGE_MASK);
660 for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
662 unsigned long pfn, mfn;
664 pfn = virt_to_pfn(va);
665 mfn = pfn_to_mfn(pfn);
667 pte = pfn_pte(pfn, PAGE_KERNEL_RO);
669 if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0))
675 if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
679 static inline bool desc_equal(const struct desc_struct *d1,
680 const struct desc_struct *d2)
682 return d1->a == d2->a && d1->b == d2->b;
685 static void load_TLS_descriptor(struct thread_struct *t,
686 unsigned int cpu, unsigned int i)
688 struct desc_struct *shadow = &per_cpu(shadow_tls_desc, cpu).desc[i];
689 struct desc_struct *gdt;
691 struct multicall_space mc;
693 if (desc_equal(shadow, &t->tls_array[i]))
696 *shadow = t->tls_array[i];
698 gdt = get_cpu_gdt_table(cpu);
699 maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
700 mc = __xen_mc_entry(0);
702 MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
705 static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
708 * XXX sleazy hack: If we're being called in a lazy-cpu zone
709 * and lazy gs handling is enabled, it means we're in a
710 * context switch, and %gs has just been saved. This means we
711 * can zero it out to prevent faults on exit from the
712 * hypervisor if the next process has no %gs. Either way, it
713 * has been saved, and the new value will get loaded properly.
714 * This will go away as soon as Xen has been modified to not
715 * save/restore %gs for normal hypercalls.
717 * On x86_64, this hack is not used for %gs, because gs points
718 * to KERNEL_GS_BASE (and uses it for PDA references), so we
719 * must not zero %gs on x86_64
721 * For x86_64, we need to zero %fs, otherwise we may get an
722 * exception between the new %fs descriptor being loaded and
723 * %fs being effectively cleared at __switch_to().
725 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
735 load_TLS_descriptor(t, cpu, 0);
736 load_TLS_descriptor(t, cpu, 1);
737 load_TLS_descriptor(t, cpu, 2);
739 xen_mc_issue(PARAVIRT_LAZY_CPU);
743 static void xen_load_gs_index(unsigned int idx)
745 if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
750 static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
753 xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
754 u64 entry = *(u64 *)ptr;
756 trace_xen_cpu_write_ldt_entry(dt, entrynum, entry);
761 if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
767 static int cvt_gate_to_trap(int vector, const gate_desc *val,
768 struct trap_info *info)
772 if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT)
775 info->vector = vector;
777 addr = gate_offset(*val);
780 * Look for known traps using IST, and substitute them
781 * appropriately. The debugger ones are the only ones we care
782 * about. Xen will handle faults like double_fault,
783 * so we should never see them. Warn if
784 * there's an unexpected IST-using fault handler.
786 if (addr == (unsigned long)debug)
787 addr = (unsigned long)xen_debug;
788 else if (addr == (unsigned long)int3)
789 addr = (unsigned long)xen_int3;
790 else if (addr == (unsigned long)stack_segment)
791 addr = (unsigned long)xen_stack_segment;
792 else if (addr == (unsigned long)double_fault) {
793 /* Don't need to handle these */
795 #ifdef CONFIG_X86_MCE
796 } else if (addr == (unsigned long)machine_check) {
798 * when xen hypervisor inject vMCE to guest,
799 * use native mce handler to handle it
803 } else if (addr == (unsigned long)nmi)
805 * Use the native version as well.
809 /* Some other trap using IST? */
810 if (WARN_ON(val->ist != 0))
813 #endif /* CONFIG_X86_64 */
814 info->address = addr;
816 info->cs = gate_segment(*val);
817 info->flags = val->dpl;
818 /* interrupt gates clear IF */
819 if (val->type == GATE_INTERRUPT)
820 info->flags |= 1 << 2;
825 /* Locations of each CPU's IDT */
826 static DEFINE_PER_CPU(struct desc_ptr, idt_desc);
828 /* Set an IDT entry. If the entry is part of the current IDT, then
830 static void xen_write_idt_entry(gate_desc *dt, int entrynum, const gate_desc *g)
832 unsigned long p = (unsigned long)&dt[entrynum];
833 unsigned long start, end;
835 trace_xen_cpu_write_idt_entry(dt, entrynum, g);
839 start = __this_cpu_read(idt_desc.address);
840 end = start + __this_cpu_read(idt_desc.size) + 1;
844 native_write_idt_entry(dt, entrynum, g);
846 if (p >= start && (p + 8) <= end) {
847 struct trap_info info[2];
851 if (cvt_gate_to_trap(entrynum, g, &info[0]))
852 if (HYPERVISOR_set_trap_table(info))
859 static void xen_convert_trap_info(const struct desc_ptr *desc,
860 struct trap_info *traps)
862 unsigned in, out, count;
864 count = (desc->size+1) / sizeof(gate_desc);
867 for (in = out = 0; in < count; in++) {
868 gate_desc *entry = (gate_desc*)(desc->address) + in;
870 if (cvt_gate_to_trap(in, entry, &traps[out]))
873 traps[out].address = 0;
876 void xen_copy_trap_info(struct trap_info *traps)
878 const struct desc_ptr *desc = this_cpu_ptr(&idt_desc);
880 xen_convert_trap_info(desc, traps);
883 /* Load a new IDT into Xen. In principle this can be per-CPU, so we
884 hold a spinlock to protect the static traps[] array (static because
885 it avoids allocation, and saves stack space). */
886 static void xen_load_idt(const struct desc_ptr *desc)
888 static DEFINE_SPINLOCK(lock);
889 static struct trap_info traps[257];
891 trace_xen_cpu_load_idt(desc);
895 memcpy(this_cpu_ptr(&idt_desc), desc, sizeof(idt_desc));
897 xen_convert_trap_info(desc, traps);
900 if (HYPERVISOR_set_trap_table(traps))
906 /* Write a GDT descriptor entry. Ignore LDT descriptors, since
907 they're handled differently. */
908 static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
909 const void *desc, int type)
911 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
922 xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]);
925 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
935 * Version of write_gdt_entry for use at early boot-time needed to
936 * update an entry as simply as possible.
938 static void __init xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
939 const void *desc, int type)
941 trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
950 xmaddr_t maddr = virt_to_machine(&dt[entry]);
952 if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
953 dt[entry] = *(struct desc_struct *)desc;
959 static void xen_load_sp0(struct tss_struct *tss,
960 struct thread_struct *thread)
962 struct multicall_space mcs;
964 mcs = xen_mc_entry(0);
965 MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
966 xen_mc_issue(PARAVIRT_LAZY_CPU);
967 tss->x86_tss.sp0 = thread->sp0;
970 void xen_set_iopl_mask(unsigned mask)
972 struct physdev_set_iopl set_iopl;
974 /* Force the change at ring 0. */
975 set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
976 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
979 static void xen_io_delay(void)
983 static DEFINE_PER_CPU(unsigned long, xen_cr0_value);
985 static unsigned long xen_read_cr0(void)
987 unsigned long cr0 = this_cpu_read(xen_cr0_value);
989 if (unlikely(cr0 == 0)) {
990 cr0 = native_read_cr0();
991 this_cpu_write(xen_cr0_value, cr0);
997 static void xen_write_cr0(unsigned long cr0)
999 struct multicall_space mcs;
1001 this_cpu_write(xen_cr0_value, cr0);
1003 /* Only pay attention to cr0.TS; everything else is
1005 mcs = xen_mc_entry(0);
1007 MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
1009 xen_mc_issue(PARAVIRT_LAZY_CPU);
1012 static void xen_write_cr4(unsigned long cr4)
1014 cr4 &= ~(X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PCE);
1016 native_write_cr4(cr4);
1018 #ifdef CONFIG_X86_64
1019 static inline unsigned long xen_read_cr8(void)
1023 static inline void xen_write_cr8(unsigned long val)
1029 static u64 xen_read_msr_safe(unsigned int msr, int *err)
1033 if (pmu_msr_read(msr, &val, err))
1036 val = native_read_msr_safe(msr, err);
1038 case MSR_IA32_APICBASE:
1039 #ifdef CONFIG_X86_X2APIC
1040 if (!(cpuid_ecx(1) & (1 << (X86_FEATURE_X2APIC & 31))))
1042 val &= ~X2APIC_ENABLE;
1048 static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
1055 #ifdef CONFIG_X86_64
1059 case MSR_FS_BASE: which = SEGBASE_FS; goto set;
1060 case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set;
1061 case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set;
1064 base = ((u64)high << 32) | low;
1065 if (HYPERVISOR_set_segment_base(which, base) != 0)
1073 case MSR_SYSCALL_MASK:
1074 case MSR_IA32_SYSENTER_CS:
1075 case MSR_IA32_SYSENTER_ESP:
1076 case MSR_IA32_SYSENTER_EIP:
1077 /* Fast syscall setup is all done in hypercalls, so
1078 these are all ignored. Stub them out here to stop
1079 Xen console noise. */
1083 if (!pmu_msr_write(msr, low, high, &ret))
1084 ret = native_write_msr_safe(msr, low, high);
1090 static u64 xen_read_msr(unsigned int msr)
1093 * This will silently swallow a #GP from RDMSR. It may be worth
1098 return xen_read_msr_safe(msr, &err);
1101 static void xen_write_msr(unsigned int msr, unsigned low, unsigned high)
1104 * This will silently swallow a #GP from WRMSR. It may be worth
1107 xen_write_msr_safe(msr, low, high);
1110 void xen_setup_shared_info(void)
1112 if (!xen_feature(XENFEAT_auto_translated_physmap)) {
1113 set_fixmap(FIX_PARAVIRT_BOOTMAP,
1114 xen_start_info->shared_info);
1116 HYPERVISOR_shared_info =
1117 (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
1119 HYPERVISOR_shared_info =
1120 (struct shared_info *)__va(xen_start_info->shared_info);
1123 /* In UP this is as good a place as any to set up shared info */
1124 xen_setup_vcpu_info_placement();
1127 xen_setup_mfn_list_list();
1130 /* This is called once we have the cpu_possible_mask */
1131 void xen_setup_vcpu_info_placement(void)
1135 for_each_possible_cpu(cpu) {
1136 /* Set up direct vCPU id mapping for PV guests. */
1137 per_cpu(xen_vcpu_id, cpu) = cpu;
1138 xen_vcpu_setup(cpu);
1141 /* xen_vcpu_setup managed to place the vcpu_info within the
1142 * percpu area for all cpus, so make use of it. Note that for
1143 * PVH we want to use native IRQ mechanism. */
1144 if (have_vcpu_info_placement && !xen_pvh_domain()) {
1145 pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
1146 pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct);
1147 pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
1148 pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
1149 pv_mmu_ops.read_cr2 = xen_read_cr2_direct;
1153 static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
1154 unsigned long addr, unsigned len)
1156 char *start, *end, *reloc;
1159 start = end = reloc = NULL;
1161 #define SITE(op, x) \
1162 case PARAVIRT_PATCH(op.x): \
1163 if (have_vcpu_info_placement) { \
1164 start = (char *)xen_##x##_direct; \
1165 end = xen_##x##_direct_end; \
1166 reloc = xen_##x##_direct_reloc; \
1171 SITE(pv_irq_ops, irq_enable);
1172 SITE(pv_irq_ops, irq_disable);
1173 SITE(pv_irq_ops, save_fl);
1174 SITE(pv_irq_ops, restore_fl);
1178 if (start == NULL || (end-start) > len)
1181 ret = paravirt_patch_insns(insnbuf, len, start, end);
1183 /* Note: because reloc is assigned from something that
1184 appears to be an array, gcc assumes it's non-null,
1185 but doesn't know its relationship with start and
1187 if (reloc > start && reloc < end) {
1188 int reloc_off = reloc - start;
1189 long *relocp = (long *)(insnbuf + reloc_off);
1190 long delta = start - (char *)addr;
1198 ret = paravirt_patch_default(type, clobbers, insnbuf,
1206 static const struct pv_info xen_info __initconst = {
1207 .shared_kernel_pmd = 0,
1209 #ifdef CONFIG_X86_64
1210 .extra_user_64bit_cs = FLAT_USER_CS64,
1215 static const struct pv_init_ops xen_init_ops __initconst = {
1219 static const struct pv_cpu_ops xen_cpu_ops __initconst = {
1222 .set_debugreg = xen_set_debugreg,
1223 .get_debugreg = xen_get_debugreg,
1225 .read_cr0 = xen_read_cr0,
1226 .write_cr0 = xen_write_cr0,
1228 .read_cr4 = native_read_cr4,
1229 .write_cr4 = xen_write_cr4,
1231 #ifdef CONFIG_X86_64
1232 .read_cr8 = xen_read_cr8,
1233 .write_cr8 = xen_write_cr8,
1236 .wbinvd = native_wbinvd,
1238 .read_msr = xen_read_msr,
1239 .write_msr = xen_write_msr,
1241 .read_msr_safe = xen_read_msr_safe,
1242 .write_msr_safe = xen_write_msr_safe,
1244 .read_pmc = xen_read_pmc,
1247 #ifdef CONFIG_X86_64
1248 .usergs_sysret64 = xen_sysret64,
1251 .load_tr_desc = paravirt_nop,
1252 .set_ldt = xen_set_ldt,
1253 .load_gdt = xen_load_gdt,
1254 .load_idt = xen_load_idt,
1255 .load_tls = xen_load_tls,
1256 #ifdef CONFIG_X86_64
1257 .load_gs_index = xen_load_gs_index,
1260 .alloc_ldt = xen_alloc_ldt,
1261 .free_ldt = xen_free_ldt,
1263 .store_idt = native_store_idt,
1264 .store_tr = xen_store_tr,
1266 .write_ldt_entry = xen_write_ldt_entry,
1267 .write_gdt_entry = xen_write_gdt_entry,
1268 .write_idt_entry = xen_write_idt_entry,
1269 .load_sp0 = xen_load_sp0,
1271 .set_iopl_mask = xen_set_iopl_mask,
1272 .io_delay = xen_io_delay,
1274 /* Xen takes care of %gs when switching to usermode for us */
1275 .swapgs = paravirt_nop,
1277 .start_context_switch = paravirt_start_context_switch,
1278 .end_context_switch = xen_end_context_switch,
1281 static void xen_reboot(int reason)
1283 struct sched_shutdown r = { .reason = reason };
1286 for_each_online_cpu(cpu)
1287 xen_pmu_finish(cpu);
1289 if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
1293 static void xen_restart(char *msg)
1295 xen_reboot(SHUTDOWN_reboot);
1298 static void xen_emergency_restart(void)
1300 xen_reboot(SHUTDOWN_reboot);
1303 static void xen_machine_halt(void)
1305 xen_reboot(SHUTDOWN_poweroff);
1308 static void xen_machine_power_off(void)
1312 xen_reboot(SHUTDOWN_poweroff);
1315 static void xen_crash_shutdown(struct pt_regs *regs)
1317 xen_reboot(SHUTDOWN_crash);
1321 xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
1323 if (!kexec_crash_loaded())
1324 xen_reboot(SHUTDOWN_crash);
1328 static struct notifier_block xen_panic_block = {
1329 .notifier_call= xen_panic_event,
1333 int xen_panic_handler_init(void)
1335 atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block);
1339 static const struct machine_ops xen_machine_ops __initconst = {
1340 .restart = xen_restart,
1341 .halt = xen_machine_halt,
1342 .power_off = xen_machine_power_off,
1343 .shutdown = xen_machine_halt,
1344 .crash_shutdown = xen_crash_shutdown,
1345 .emergency_restart = xen_emergency_restart,
1348 static unsigned char xen_get_nmi_reason(void)
1350 unsigned char reason = 0;
1352 /* Construct a value which looks like it came from port 0x61. */
1353 if (test_bit(_XEN_NMIREASON_io_error,
1354 &HYPERVISOR_shared_info->arch.nmi_reason))
1355 reason |= NMI_REASON_IOCHK;
1356 if (test_bit(_XEN_NMIREASON_pci_serr,
1357 &HYPERVISOR_shared_info->arch.nmi_reason))
1358 reason |= NMI_REASON_SERR;
1363 static void __init xen_boot_params_init_edd(void)
1365 #if IS_ENABLED(CONFIG_EDD)
1366 struct xen_platform_op op;
1367 struct edd_info *edd_info;
1372 edd_info = boot_params.eddbuf;
1373 mbr_signature = boot_params.edd_mbr_sig_buffer;
1375 op.cmd = XENPF_firmware_info;
1377 op.u.firmware_info.type = XEN_FW_DISK_INFO;
1378 for (nr = 0; nr < EDDMAXNR; nr++) {
1379 struct edd_info *info = edd_info + nr;
1381 op.u.firmware_info.index = nr;
1382 info->params.length = sizeof(info->params);
1383 set_xen_guest_handle(op.u.firmware_info.u.disk_info.edd_params,
1385 ret = HYPERVISOR_platform_op(&op);
1389 #define C(x) info->x = op.u.firmware_info.u.disk_info.x
1392 C(interface_support);
1393 C(legacy_max_cylinder);
1395 C(legacy_sectors_per_track);
1398 boot_params.eddbuf_entries = nr;
1400 op.u.firmware_info.type = XEN_FW_DISK_MBR_SIGNATURE;
1401 for (nr = 0; nr < EDD_MBR_SIG_MAX; nr++) {
1402 op.u.firmware_info.index = nr;
1403 ret = HYPERVISOR_platform_op(&op);
1406 mbr_signature[nr] = op.u.firmware_info.u.disk_mbr_signature.mbr_signature;
1408 boot_params.edd_mbr_sig_buf_entries = nr;
1413 * Set up the GDT and segment registers for -fstack-protector. Until
1414 * we do this, we have to be careful not to call any stack-protected
1415 * function, which is most of the kernel.
1417 * Note, that it is __ref because the only caller of this after init
1418 * is PVH which is not going to use xen_load_gdt_boot or other
1421 static void __ref xen_setup_gdt(int cpu)
1423 if (xen_feature(XENFEAT_auto_translated_physmap)) {
1424 #ifdef CONFIG_X86_64
1425 unsigned long dummy;
1427 load_percpu_segment(cpu); /* We need to access per-cpu area */
1428 switch_to_new_gdt(cpu); /* GDT and GS set */
1430 /* We are switching of the Xen provided GDT to our HVM mode
1431 * GDT. The new GDT has __KERNEL_CS with CS.L = 1
1432 * and we are jumping to reload it.
1434 asm volatile ("pushq %0\n"
1435 "leaq 1f(%%rip),%0\n"
1439 : "=&r" (dummy) : "0" (__KERNEL_CS));
1442 * While not needed, we also set the %es, %ds, and %fs
1443 * to zero. We don't care about %ss as it is NULL.
1444 * Strictly speaking this is not needed as Xen zeros those
1445 * out (and also MSR_FS_BASE, MSR_GS_BASE, MSR_KERNEL_GS_BASE)
1447 * Linux zeros them in cpu_init() and in secondary_startup_64
1454 /* PVH: TODO Implement. */
1457 return; /* PVH does not need any PV GDT ops. */
1459 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
1460 pv_cpu_ops.load_gdt = xen_load_gdt_boot;
1462 setup_stack_canary_segment(0);
1463 switch_to_new_gdt(0);
1465 pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry;
1466 pv_cpu_ops.load_gdt = xen_load_gdt;
1469 #ifdef CONFIG_XEN_PVH
1471 * A PV guest starts with default flags that are not set for PVH, set them
1474 static void xen_pvh_set_cr_flags(int cpu)
1477 /* Some of these are setup in 'secondary_startup_64'. The others:
1478 * X86_CR0_TS, X86_CR0_PE, X86_CR0_ET are set by Xen for HVM guests
1479 * (which PVH shared codepaths), while X86_CR0_PG is for PVH. */
1480 write_cr0(read_cr0() | X86_CR0_MP | X86_CR0_NE | X86_CR0_WP | X86_CR0_AM);
1485 * For BSP, PSE PGE are set in probe_page_size_mask(), for APs
1486 * set them here. For all, OSFXSR OSXMMEXCPT are set in fpu__init_cpu().
1488 if (boot_cpu_has(X86_FEATURE_PSE))
1489 cr4_set_bits_and_update_boot(X86_CR4_PSE);
1491 if (boot_cpu_has(X86_FEATURE_PGE))
1492 cr4_set_bits_and_update_boot(X86_CR4_PGE);
1496 * Note, that it is ref - because the only caller of this after init
1497 * is PVH which is not going to use xen_load_gdt_boot or other
1500 void __ref xen_pvh_secondary_vcpu_init(int cpu)
1503 xen_pvh_set_cr_flags(cpu);
1506 static void __init xen_pvh_early_guest_init(void)
1508 if (!xen_feature(XENFEAT_auto_translated_physmap))
1511 BUG_ON(!xen_feature(XENFEAT_hvm_callback_vector));
1513 xen_pvh_early_cpu_init(0, false);
1514 xen_pvh_set_cr_flags(0);
1516 #ifdef CONFIG_X86_32
1517 BUG(); /* PVH: Implement proper support. */
1520 #endif /* CONFIG_XEN_PVH */
1522 static void __init xen_dom0_set_legacy_features(void)
1524 x86_platform.legacy.rtc = 1;
1527 static int xen_cpuhp_setup(void)
1531 rc = cpuhp_setup_state_nocalls(CPUHP_XEN_PREPARE,
1532 "x86/xen/hvm_guest:prepare",
1533 xen_cpu_up_prepare, xen_cpu_dead);
1535 rc = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
1536 "x86/xen/hvm_guest:online",
1537 xen_cpu_up_online, NULL);
1539 cpuhp_remove_state_nocalls(CPUHP_XEN_PREPARE);
1542 return rc >= 0 ? 0 : rc;
1545 /* First C function to be called on Xen boot */
1546 asmlinkage __visible void __init xen_start_kernel(void)
1548 struct physdev_set_iopl set_iopl;
1549 unsigned long initrd_start = 0;
1552 if (!xen_start_info)
1555 xen_domain_type = XEN_PV_DOMAIN;
1557 xen_setup_features();
1558 #ifdef CONFIG_XEN_PVH
1559 xen_pvh_early_guest_init();
1561 xen_setup_machphys_mapping();
1563 /* Install Xen paravirt ops */
1565 pv_init_ops = xen_init_ops;
1566 if (!xen_pvh_domain()) {
1567 pv_cpu_ops = xen_cpu_ops;
1569 x86_platform.get_nmi_reason = xen_get_nmi_reason;
1572 if (xen_feature(XENFEAT_auto_translated_physmap))
1573 x86_init.resources.memory_setup = xen_auto_xlated_memory_setup;
1575 x86_init.resources.memory_setup = xen_memory_setup;
1576 x86_init.oem.arch_setup = xen_arch_setup;
1577 x86_init.oem.banner = xen_banner;
1579 xen_init_time_ops();
1582 * Set up some pagetable state before starting to set any ptes.
1587 /* Prevent unwanted bits from being set in PTEs. */
1588 __supported_pte_mask &= ~_PAGE_GLOBAL;
1591 * Prevent page tables from being allocated in highmem, even
1592 * if CONFIG_HIGHPTE is enabled.
1594 __userpte_alloc_gfp &= ~__GFP_HIGHMEM;
1596 /* Work out if we support NX */
1600 xen_build_dynamic_phys_to_machine();
1603 * Set up kernel GDT and segment registers, mainly so that
1604 * -fstack-protector code can be executed.
1609 xen_init_cpuid_mask();
1611 #ifdef CONFIG_X86_LOCAL_APIC
1613 * set up the basic apic ops.
1618 if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
1619 pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
1620 pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
1623 machine_ops = xen_machine_ops;
1626 * The only reliable way to retain the initial address of the
1627 * percpu gdt_page is to remember it here, so we can go and
1628 * mark it RW later, when the initial percpu area is freed.
1630 xen_initial_gdt = &per_cpu(gdt_page, 0);
1634 #ifdef CONFIG_ACPI_NUMA
1636 * The pages we from Xen are not related to machine pages, so
1637 * any NUMA information the kernel tries to get from ACPI will
1638 * be meaningless. Prevent it from trying.
1642 /* Don't do the full vcpu_info placement stuff until we have a
1643 possible map and a non-dummy shared_info. */
1644 per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
1646 WARN_ON(xen_cpuhp_setup());
1648 local_irq_disable();
1649 early_boot_irqs_disabled = true;
1651 xen_raw_console_write("mapping kernel into physical memory\n");
1652 xen_setup_kernel_pagetable((pgd_t *)xen_start_info->pt_base,
1653 xen_start_info->nr_pages);
1654 xen_reserve_special_pages();
1656 /* keep using Xen gdt for now; no urgent need to change it */
1658 #ifdef CONFIG_X86_32
1659 pv_info.kernel_rpl = 1;
1660 if (xen_feature(XENFEAT_supervisor_mode_kernel))
1661 pv_info.kernel_rpl = 0;
1663 pv_info.kernel_rpl = 0;
1665 /* set the limit of our address space */
1668 /* PVH: runs at default kernel iopl of 0 */
1669 if (!xen_pvh_domain()) {
1671 * We used to do this in xen_arch_setup, but that is too late
1672 * on AMD were early_cpu_init (run before ->arch_setup()) calls
1673 * early_amd_init which pokes 0xcf8 port.
1676 rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
1678 xen_raw_printk("physdev_op failed %d\n", rc);
1681 #ifdef CONFIG_X86_32
1682 /* set up basic CPUID stuff */
1683 cpu_detect(&new_cpu_data);
1684 set_cpu_cap(&new_cpu_data, X86_FEATURE_FPU);
1685 new_cpu_data.wp_works_ok = 1;
1686 new_cpu_data.x86_capability[CPUID_1_EDX] = cpuid_edx(1);
1689 if (xen_start_info->mod_start) {
1690 if (xen_start_info->flags & SIF_MOD_START_PFN)
1691 initrd_start = PFN_PHYS(xen_start_info->mod_start);
1693 initrd_start = __pa(xen_start_info->mod_start);
1696 /* Poke various useful things into boot_params */
1697 boot_params.hdr.type_of_loader = (9 << 4) | 0;
1698 boot_params.hdr.ramdisk_image = initrd_start;
1699 boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
1700 boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
1701 boot_params.hdr.hardware_subarch = X86_SUBARCH_XEN;
1703 if (!xen_initial_domain()) {
1704 add_preferred_console("xenboot", 0, NULL);
1705 add_preferred_console("tty", 0, NULL);
1706 add_preferred_console("hvc", 0, NULL);
1708 x86_init.pci.arch_init = pci_xen_init;
1710 const struct dom0_vga_console_info *info =
1711 (void *)((char *)xen_start_info +
1712 xen_start_info->console.dom0.info_off);
1713 struct xen_platform_op op = {
1714 .cmd = XENPF_firmware_info,
1715 .interface_version = XENPF_INTERFACE_VERSION,
1716 .u.firmware_info.type = XEN_FW_KBD_SHIFT_FLAGS,
1719 x86_platform.set_legacy_features =
1720 xen_dom0_set_legacy_features;
1721 xen_init_vga(info, xen_start_info->console.dom0.info_size);
1722 xen_start_info->console.domU.mfn = 0;
1723 xen_start_info->console.domU.evtchn = 0;
1725 if (HYPERVISOR_platform_op(&op) == 0)
1726 boot_params.kbd_status = op.u.firmware_info.u.kbd_shift_flags;
1728 /* Make sure ACS will be enabled */
1731 xen_acpi_sleep_register();
1733 /* Avoid searching for BIOS MP tables */
1734 x86_init.mpparse.find_smp_config = x86_init_noop;
1735 x86_init.mpparse.get_smp_config = x86_init_uint_noop;
1737 xen_boot_params_init_edd();
1740 /* PCI BIOS service won't work from a PV guest. */
1741 pci_probe &= ~PCI_PROBE_BIOS;
1743 xen_raw_console_write("about to get started...\n");
1745 /* Let's presume PV guests always boot on vCPU with id 0. */
1746 per_cpu(xen_vcpu_id, 0) = 0;
1748 xen_setup_runstate_info(0);
1752 /* Start the world */
1753 #ifdef CONFIG_X86_32
1754 i386_start_kernel();
1756 cr4_init_shadow(); /* 32b kernel does this in i386_start_kernel() */
1757 x86_64_start_reservations((char *)__pa_symbol(&boot_params));
1761 void __ref xen_hvm_init_shared_info(void)
1764 struct xen_add_to_physmap xatp;
1765 static struct shared_info *shared_info_page = 0;
1767 if (!shared_info_page)
1768 shared_info_page = (struct shared_info *)
1769 extend_brk(PAGE_SIZE, PAGE_SIZE);
1770 xatp.domid = DOMID_SELF;
1772 xatp.space = XENMAPSPACE_shared_info;
1773 xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
1774 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
1777 HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
1779 /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
1780 * page, we use it in the event channel upcall and in some pvclock
1781 * related functions. We don't need the vcpu_info placement
1782 * optimizations because we don't use any pv_mmu or pv_irq op on
1784 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
1785 * online but xen_hvm_init_shared_info is run at resume time too and
1786 * in that case multiple vcpus might be online. */
1787 for_each_online_cpu(cpu) {
1788 /* Leave it to be NULL. */
1789 if (xen_vcpu_nr(cpu) >= MAX_VIRT_CPUS)
1791 per_cpu(xen_vcpu, cpu) =
1792 &HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
1796 #ifdef CONFIG_XEN_PVHVM
1797 static void __init init_hvm_pv_info(void)
1800 uint32_t eax, ebx, ecx, edx, pages, msr, base;
1803 base = xen_cpuid_base();
1804 cpuid(base + 1, &eax, &ebx, &ecx, &edx);
1807 minor = eax & 0xffff;
1808 printk(KERN_INFO "Xen version %d.%d.\n", major, minor);
1810 cpuid(base + 2, &pages, &msr, &ecx, &edx);
1812 pfn = __pa(hypercall_page);
1813 wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
1815 xen_setup_features();
1817 cpuid(base + 4, &eax, &ebx, &ecx, &edx);
1818 if (eax & XEN_HVM_CPUID_VCPU_ID_PRESENT)
1819 this_cpu_write(xen_vcpu_id, ebx);
1821 this_cpu_write(xen_vcpu_id, smp_processor_id());
1823 pv_info.name = "Xen HVM";
1825 xen_domain_type = XEN_HVM_DOMAIN;
1829 static int xen_cpu_up_prepare(unsigned int cpu)
1833 if (xen_hvm_domain()) {
1835 * This can happen if CPU was offlined earlier and
1836 * offlining timed out in common_cpu_die().
1838 if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) {
1839 xen_smp_intr_free(cpu);
1840 xen_uninit_lock_cpu(cpu);
1843 if (cpu_acpi_id(cpu) != U32_MAX)
1844 per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);
1846 per_cpu(xen_vcpu_id, cpu) = cpu;
1847 xen_vcpu_setup(cpu);
1850 if (xen_pv_domain() || xen_feature(XENFEAT_hvm_safe_pvclock))
1851 xen_setup_timer(cpu);
1853 rc = xen_smp_intr_init(cpu);
1855 WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n",
1862 static int xen_cpu_dead(unsigned int cpu)
1864 xen_smp_intr_free(cpu);
1866 if (xen_pv_domain() || xen_feature(XENFEAT_hvm_safe_pvclock))
1867 xen_teardown_timer(cpu);
1872 static int xen_cpu_up_online(unsigned int cpu)
1874 xen_init_lock_cpu(cpu);
1878 #ifdef CONFIG_XEN_PVHVM
1879 #ifdef CONFIG_KEXEC_CORE
1880 static void xen_hvm_shutdown(void)
1882 native_machine_shutdown();
1883 if (kexec_in_progress)
1884 xen_reboot(SHUTDOWN_soft_reset);
1887 static void xen_hvm_crash_shutdown(struct pt_regs *regs)
1889 native_machine_crash_shutdown(regs);
1890 xen_reboot(SHUTDOWN_soft_reset);
1894 static void __init xen_hvm_guest_init(void)
1896 if (xen_pv_domain())
1901 xen_hvm_init_shared_info();
1903 xen_panic_handler_init();
1905 BUG_ON(!xen_feature(XENFEAT_hvm_callback_vector));
1908 WARN_ON(xen_cpuhp_setup());
1909 xen_unplug_emulated_devices();
1910 x86_init.irqs.intr_init = xen_init_IRQ;
1911 xen_hvm_init_time_ops();
1912 xen_hvm_init_mmu_ops();
1913 #ifdef CONFIG_KEXEC_CORE
1914 machine_ops.shutdown = xen_hvm_shutdown;
1915 machine_ops.crash_shutdown = xen_hvm_crash_shutdown;
1920 static bool xen_nopv = false;
1921 static __init int xen_parse_nopv(char *arg)
1926 early_param("xen_nopv", xen_parse_nopv);
1928 static uint32_t __init xen_platform(void)
1933 return xen_cpuid_base();
1936 bool xen_hvm_need_lapic(void)
1940 if (xen_pv_domain())
1942 if (!xen_hvm_domain())
1944 if (xen_feature(XENFEAT_hvm_pirqs))
1948 EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
1950 static void xen_set_cpu_features(struct cpuinfo_x86 *c)
1952 if (xen_pv_domain()) {
1953 clear_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
1954 set_cpu_cap(c, X86_FEATURE_XENPV);
1958 static void xen_pin_vcpu(int cpu)
1960 static bool disable_pinning;
1961 struct sched_pin_override pin_override;
1964 if (disable_pinning)
1967 pin_override.pcpu = cpu;
1968 ret = HYPERVISOR_sched_op(SCHEDOP_pin_override, &pin_override);
1970 /* Ignore errors when removing override. */
1976 pr_warn("Unable to pin on physical cpu %d. In case of problems consider vcpu pinning.\n",
1978 disable_pinning = true;
1981 WARN(1, "Trying to pin vcpu without having privilege to do so\n");
1982 disable_pinning = true;
1986 pr_warn("Physical cpu %d not available for pinning. Check Xen cpu configuration.\n",
1992 WARN(1, "rc %d while trying to pin vcpu\n", ret);
1993 disable_pinning = true;
1997 const struct hypervisor_x86 x86_hyper_xen = {
1999 .detect = xen_platform,
2000 #ifdef CONFIG_XEN_PVHVM
2001 .init_platform = xen_hvm_guest_init,
2003 .x2apic_available = xen_x2apic_para_available,
2004 .set_cpu_features = xen_set_cpu_features,
2005 .pin_vcpu = xen_pin_vcpu,
2007 EXPORT_SYMBOL(x86_hyper_xen);
2009 #ifdef CONFIG_HOTPLUG_CPU
2010 void xen_arch_register_cpu(int num)
2012 arch_register_cpu(num);
2014 EXPORT_SYMBOL(xen_arch_register_cpu);
2016 void xen_arch_unregister_cpu(int num)
2018 arch_unregister_cpu(num);
2020 EXPORT_SYMBOL(xen_arch_unregister_cpu);