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
);
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
);