2 * Core of Xen paravirt_ops implementation.
4 * This file contains the xen_paravirt_ops structure itself, and the
6 * - privileged instructions
11 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
14 #include <linux/cpu.h>
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/smp.h>
18 #include <linux/preempt.h>
19 #include <linux/hardirq.h>
20 #include <linux/percpu.h>
21 #include <linux/delay.h>
22 #include <linux/start_kernel.h>
23 #include <linux/sched.h>
24 #include <linux/kprobes.h>
25 #include <linux/bootmem.h>
26 #include <linux/module.h>
28 #include <linux/page-flags.h>
29 #include <linux/highmem.h>
30 #include <linux/console.h>
31 #include <linux/pci.h>
32 #include <linux/gfp.h>
33 #include <linux/memblock.h>
36 #include <xen/events.h>
37 #include <xen/interface/xen.h>
38 #include <xen/interface/version.h>
39 #include <xen/interface/physdev.h>
40 #include <xen/interface/vcpu.h>
41 #include <xen/interface/memory.h>
42 #include <xen/interface/xen-mca.h>
43 #include <xen/features.h>
46 #include <xen/hvc-console.h>
49 #include <asm/paravirt.h>
52 #include <asm/xen/pci.h>
53 #include <asm/xen/hypercall.h>
54 #include <asm/xen/hypervisor.h>
55 #include <asm/fixmap.h>
56 #include <asm/processor.h>
57 #include <asm/proto.h>
58 #include <asm/msr-index.h>
59 #include <asm/traps.h>
60 #include <asm/setup.h>
62 #include <asm/pgalloc.h>
63 #include <asm/pgtable.h>
64 #include <asm/tlbflush.h>
65 #include <asm/reboot.h>
66 #include <asm/stackprotector.h>
67 #include <asm/hypervisor.h>
68 #include <asm/mwait.h>
69 #include <asm/pci_x86.h>
72 #include <linux/acpi.h>
74 #include <acpi/pdc_intel.h>
75 #include <acpi/processor.h>
76 #include <xen/interface/platform.h>
82 #include "multicalls.h"
84 #include <xen/events.h>
86 EXPORT_SYMBOL_GPL(hypercall_page
);
88 DEFINE_PER_CPU(struct vcpu_info
*, xen_vcpu
);
89 DEFINE_PER_CPU(struct vcpu_info
, xen_vcpu_info
);
91 enum xen_domain_type xen_domain_type
= XEN_NATIVE
;
92 EXPORT_SYMBOL_GPL(xen_domain_type
);
94 unsigned long *machine_to_phys_mapping
= (void *)MACH2PHYS_VIRT_START
;
95 EXPORT_SYMBOL(machine_to_phys_mapping
);
96 unsigned long machine_to_phys_nr
;
97 EXPORT_SYMBOL(machine_to_phys_nr
);
99 struct start_info
*xen_start_info
;
100 EXPORT_SYMBOL_GPL(xen_start_info
);
102 struct shared_info xen_dummy_shared_info
;
104 void *xen_initial_gdt
;
106 RESERVE_BRK(shared_info_page_brk
, PAGE_SIZE
);
107 __read_mostly
int xen_have_vector_callback
;
108 EXPORT_SYMBOL_GPL(xen_have_vector_callback
);
111 * Point at some empty memory to start with. We map the real shared_info
112 * page as soon as fixmap is up and running.
114 struct shared_info
*HYPERVISOR_shared_info
= &xen_dummy_shared_info
;
117 * Flag to determine whether vcpu info placement is available on all
118 * VCPUs. We assume it is to start with, and then set it to zero on
119 * the first failure. This is because it can succeed on some VCPUs
120 * and not others, since it can involve hypervisor memory allocation,
121 * or because the guest failed to guarantee all the appropriate
122 * constraints on all VCPUs (ie buffer can't cross a page boundary).
124 * Note that any particular CPU may be using a placed vcpu structure,
125 * but we can only optimise if the all are.
127 * 0: not available, 1: available
129 static int have_vcpu_info_placement
= 1;
132 struct desc_struct desc
[3];
136 * Updating the 3 TLS descriptors in the GDT on every task switch is
137 * surprisingly expensive so we avoid updating them if they haven't
138 * changed. Since Xen writes different descriptors than the one
139 * passed in the update_descriptor hypercall we keep shadow copies to
142 static DEFINE_PER_CPU(struct tls_descs
, shadow_tls_desc
);
144 static void clamp_max_cpus(void)
147 if (setup_max_cpus
> MAX_VIRT_CPUS
)
148 setup_max_cpus
= MAX_VIRT_CPUS
;
152 static void xen_vcpu_setup(int cpu
)
154 struct vcpu_register_vcpu_info info
;
156 struct vcpu_info
*vcpup
;
158 BUG_ON(HYPERVISOR_shared_info
== &xen_dummy_shared_info
);
160 if (cpu
< MAX_VIRT_CPUS
)
161 per_cpu(xen_vcpu
,cpu
) = &HYPERVISOR_shared_info
->vcpu_info
[cpu
];
163 if (!have_vcpu_info_placement
) {
164 if (cpu
>= MAX_VIRT_CPUS
)
169 vcpup
= &per_cpu(xen_vcpu_info
, cpu
);
170 info
.mfn
= arbitrary_virt_to_mfn(vcpup
);
171 info
.offset
= offset_in_page(vcpup
);
173 /* Check to see if the hypervisor will put the vcpu_info
174 structure where we want it, which allows direct access via
175 a percpu-variable. */
176 err
= HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info
, cpu
, &info
);
179 printk(KERN_DEBUG
"register_vcpu_info failed: err=%d\n", err
);
180 have_vcpu_info_placement
= 0;
183 /* This cpu is using the registered vcpu info, even if
184 later ones fail to. */
185 per_cpu(xen_vcpu
, cpu
) = vcpup
;
190 * On restore, set the vcpu placement up again.
191 * If it fails, then we're in a bad state, since
192 * we can't back out from using it...
194 void xen_vcpu_restore(void)
198 for_each_online_cpu(cpu
) {
199 bool other_cpu
= (cpu
!= smp_processor_id());
202 HYPERVISOR_vcpu_op(VCPUOP_down
, cpu
, NULL
))
205 xen_setup_runstate_info(cpu
);
207 if (have_vcpu_info_placement
)
211 HYPERVISOR_vcpu_op(VCPUOP_up
, cpu
, NULL
))
216 static void __init
xen_banner(void)
218 unsigned version
= HYPERVISOR_xen_version(XENVER_version
, NULL
);
219 struct xen_extraversion extra
;
220 HYPERVISOR_xen_version(XENVER_extraversion
, &extra
);
222 printk(KERN_INFO
"Booting paravirtualized kernel on %s\n",
224 printk(KERN_INFO
"Xen version: %d.%d%s%s\n",
225 version
>> 16, version
& 0xffff, extra
.extraversion
,
226 xen_feature(XENFEAT_mmu_pt_update_preserve_ad
) ? " (preserve-AD)" : "");
229 #define CPUID_THERM_POWER_LEAF 6
230 #define APERFMPERF_PRESENT 0
232 static __read_mostly
unsigned int cpuid_leaf1_edx_mask
= ~0;
233 static __read_mostly
unsigned int cpuid_leaf1_ecx_mask
= ~0;
235 static __read_mostly
unsigned int cpuid_leaf1_ecx_set_mask
;
236 static __read_mostly
unsigned int cpuid_leaf5_ecx_val
;
237 static __read_mostly
unsigned int cpuid_leaf5_edx_val
;
239 static void xen_cpuid(unsigned int *ax
, unsigned int *bx
,
240 unsigned int *cx
, unsigned int *dx
)
242 unsigned maskebx
= ~0;
243 unsigned maskecx
= ~0;
244 unsigned maskedx
= ~0;
247 * Mask out inconvenient features, to try and disable as many
248 * unsupported kernel subsystems as possible.
252 maskecx
= cpuid_leaf1_ecx_mask
;
253 setecx
= cpuid_leaf1_ecx_set_mask
;
254 maskedx
= cpuid_leaf1_edx_mask
;
257 case CPUID_MWAIT_LEAF
:
258 /* Synthesize the values.. */
261 *cx
= cpuid_leaf5_ecx_val
;
262 *dx
= cpuid_leaf5_edx_val
;
265 case CPUID_THERM_POWER_LEAF
:
266 /* Disabling APERFMPERF for kernel usage */
267 maskecx
= ~(1 << APERFMPERF_PRESENT
);
271 /* Suppress extended topology stuff */
276 asm(XEN_EMULATE_PREFIX
"cpuid"
281 : "0" (*ax
), "2" (*cx
));
290 static bool __init
xen_check_mwait(void)
292 #if defined(CONFIG_ACPI) && !defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR) && \
293 !defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR_MODULE)
294 struct xen_platform_op op
= {
295 .cmd
= XENPF_set_processor_pminfo
,
296 .u
.set_pminfo
.id
= -1,
297 .u
.set_pminfo
.type
= XEN_PM_PDC
,
300 unsigned int ax
, bx
, cx
, dx
;
301 unsigned int mwait_mask
;
303 /* We need to determine whether it is OK to expose the MWAIT
304 * capability to the kernel to harvest deeper than C3 states from ACPI
305 * _CST using the processor_harvest_xen.c module. For this to work, we
306 * need to gather the MWAIT_LEAF values (which the cstate.c code
307 * checks against). The hypervisor won't expose the MWAIT flag because
308 * it would break backwards compatibility; so we will find out directly
309 * from the hardware and hypercall.
311 if (!xen_initial_domain())
317 native_cpuid(&ax
, &bx
, &cx
, &dx
);
319 mwait_mask
= (1 << (X86_FEATURE_EST
% 32)) |
320 (1 << (X86_FEATURE_MWAIT
% 32));
322 if ((cx
& mwait_mask
) != mwait_mask
)
325 /* We need to emulate the MWAIT_LEAF and for that we need both
326 * ecx and edx. The hypercall provides only partial information.
329 ax
= CPUID_MWAIT_LEAF
;
334 native_cpuid(&ax
, &bx
, &cx
, &dx
);
336 /* Ask the Hypervisor whether to clear ACPI_PDC_C_C2C3_FFH. If so,
337 * don't expose MWAIT_LEAF and let ACPI pick the IOPORT version of C3.
339 buf
[0] = ACPI_PDC_REVISION_ID
;
341 buf
[2] = (ACPI_PDC_C_CAPABILITY_SMP
| ACPI_PDC_EST_CAPABILITY_SWSMP
);
343 set_xen_guest_handle(op
.u
.set_pminfo
.pdc
, buf
);
345 if ((HYPERVISOR_dom0_op(&op
) == 0) &&
346 (buf
[2] & (ACPI_PDC_C_C1_FFH
| ACPI_PDC_C_C2C3_FFH
))) {
347 cpuid_leaf5_ecx_val
= cx
;
348 cpuid_leaf5_edx_val
= dx
;
355 static void __init
xen_init_cpuid_mask(void)
357 unsigned int ax
, bx
, cx
, dx
;
358 unsigned int xsave_mask
;
360 cpuid_leaf1_edx_mask
=
361 ~((1 << X86_FEATURE_MTRR
) | /* disable MTRR */
362 (1 << X86_FEATURE_ACC
)); /* thermal monitoring */
364 if (!xen_initial_domain())
365 cpuid_leaf1_edx_mask
&=
366 ~((1 << X86_FEATURE_APIC
) | /* disable local APIC */
367 (1 << X86_FEATURE_ACPI
)); /* disable ACPI */
370 xen_cpuid(&ax
, &bx
, &cx
, &dx
);
373 (1 << (X86_FEATURE_XSAVE
% 32)) |
374 (1 << (X86_FEATURE_OSXSAVE
% 32));
376 /* Xen will set CR4.OSXSAVE if supported and not disabled by force */
377 if ((cx
& xsave_mask
) != xsave_mask
)
378 cpuid_leaf1_ecx_mask
&= ~xsave_mask
; /* disable XSAVE & OSXSAVE */
379 if (xen_check_mwait())
380 cpuid_leaf1_ecx_set_mask
= (1 << (X86_FEATURE_MWAIT
% 32));
383 static void xen_set_debugreg(int reg
, unsigned long val
)
385 HYPERVISOR_set_debugreg(reg
, val
);
388 static unsigned long xen_get_debugreg(int reg
)
390 return HYPERVISOR_get_debugreg(reg
);
393 static void xen_end_context_switch(struct task_struct
*next
)
396 paravirt_end_context_switch(next
);
399 static unsigned long xen_store_tr(void)
405 * Set the page permissions for a particular virtual address. If the
406 * address is a vmalloc mapping (or other non-linear mapping), then
407 * find the linear mapping of the page and also set its protections to
410 static void set_aliased_prot(void *v
, pgprot_t prot
)
418 ptep
= lookup_address((unsigned long)v
, &level
);
419 BUG_ON(ptep
== NULL
);
421 pfn
= pte_pfn(*ptep
);
422 page
= pfn_to_page(pfn
);
424 pte
= pfn_pte(pfn
, prot
);
426 if (HYPERVISOR_update_va_mapping((unsigned long)v
, pte
, 0))
429 if (!PageHighMem(page
)) {
430 void *av
= __va(PFN_PHYS(pfn
));
433 if (HYPERVISOR_update_va_mapping((unsigned long)av
, pte
, 0))
439 static void xen_alloc_ldt(struct desc_struct
*ldt
, unsigned entries
)
441 const unsigned entries_per_page
= PAGE_SIZE
/ LDT_ENTRY_SIZE
;
444 for(i
= 0; i
< entries
; i
+= entries_per_page
)
445 set_aliased_prot(ldt
+ i
, PAGE_KERNEL_RO
);
448 static void xen_free_ldt(struct desc_struct
*ldt
, unsigned entries
)
450 const unsigned entries_per_page
= PAGE_SIZE
/ LDT_ENTRY_SIZE
;
453 for(i
= 0; i
< entries
; i
+= entries_per_page
)
454 set_aliased_prot(ldt
+ i
, PAGE_KERNEL
);
457 static void xen_set_ldt(const void *addr
, unsigned entries
)
459 struct mmuext_op
*op
;
460 struct multicall_space mcs
= xen_mc_entry(sizeof(*op
));
462 trace_xen_cpu_set_ldt(addr
, entries
);
465 op
->cmd
= MMUEXT_SET_LDT
;
466 op
->arg1
.linear_addr
= (unsigned long)addr
;
467 op
->arg2
.nr_ents
= entries
;
469 MULTI_mmuext_op(mcs
.mc
, op
, 1, NULL
, DOMID_SELF
);
471 xen_mc_issue(PARAVIRT_LAZY_CPU
);
474 static void xen_load_gdt(const struct desc_ptr
*dtr
)
476 unsigned long va
= dtr
->address
;
477 unsigned int size
= dtr
->size
+ 1;
478 unsigned pages
= (size
+ PAGE_SIZE
- 1) / PAGE_SIZE
;
479 unsigned long frames
[pages
];
483 * A GDT can be up to 64k in size, which corresponds to 8192
484 * 8-byte entries, or 16 4k pages..
487 BUG_ON(size
> 65536);
488 BUG_ON(va
& ~PAGE_MASK
);
490 for (f
= 0; va
< dtr
->address
+ size
; va
+= PAGE_SIZE
, f
++) {
493 unsigned long pfn
, mfn
;
497 * The GDT is per-cpu and is in the percpu data area.
498 * That can be virtually mapped, so we need to do a
499 * page-walk to get the underlying MFN for the
500 * hypercall. The page can also be in the kernel's
501 * linear range, so we need to RO that mapping too.
503 ptep
= lookup_address(va
, &level
);
504 BUG_ON(ptep
== NULL
);
506 pfn
= pte_pfn(*ptep
);
507 mfn
= pfn_to_mfn(pfn
);
508 virt
= __va(PFN_PHYS(pfn
));
512 make_lowmem_page_readonly((void *)va
);
513 make_lowmem_page_readonly(virt
);
516 if (HYPERVISOR_set_gdt(frames
, size
/ sizeof(struct desc_struct
)))
521 * load_gdt for early boot, when the gdt is only mapped once
523 static void __init
xen_load_gdt_boot(const struct desc_ptr
*dtr
)
525 unsigned long va
= dtr
->address
;
526 unsigned int size
= dtr
->size
+ 1;
527 unsigned pages
= (size
+ PAGE_SIZE
- 1) / PAGE_SIZE
;
528 unsigned long frames
[pages
];
532 * A GDT can be up to 64k in size, which corresponds to 8192
533 * 8-byte entries, or 16 4k pages..
536 BUG_ON(size
> 65536);
537 BUG_ON(va
& ~PAGE_MASK
);
539 for (f
= 0; va
< dtr
->address
+ size
; va
+= PAGE_SIZE
, f
++) {
541 unsigned long pfn
, mfn
;
543 pfn
= virt_to_pfn(va
);
544 mfn
= pfn_to_mfn(pfn
);
546 pte
= pfn_pte(pfn
, PAGE_KERNEL_RO
);
548 if (HYPERVISOR_update_va_mapping((unsigned long)va
, pte
, 0))
554 if (HYPERVISOR_set_gdt(frames
, size
/ sizeof(struct desc_struct
)))
558 static inline bool desc_equal(const struct desc_struct
*d1
,
559 const struct desc_struct
*d2
)
561 return d1
->a
== d2
->a
&& d1
->b
== d2
->b
;
564 static void load_TLS_descriptor(struct thread_struct
*t
,
565 unsigned int cpu
, unsigned int i
)
567 struct desc_struct
*shadow
= &per_cpu(shadow_tls_desc
, cpu
).desc
[i
];
568 struct desc_struct
*gdt
;
570 struct multicall_space mc
;
572 if (desc_equal(shadow
, &t
->tls_array
[i
]))
575 *shadow
= t
->tls_array
[i
];
577 gdt
= get_cpu_gdt_table(cpu
);
578 maddr
= arbitrary_virt_to_machine(&gdt
[GDT_ENTRY_TLS_MIN
+i
]);
579 mc
= __xen_mc_entry(0);
581 MULTI_update_descriptor(mc
.mc
, maddr
.maddr
, t
->tls_array
[i
]);
584 static void xen_load_tls(struct thread_struct
*t
, unsigned int cpu
)
587 * XXX sleazy hack: If we're being called in a lazy-cpu zone
588 * and lazy gs handling is enabled, it means we're in a
589 * context switch, and %gs has just been saved. This means we
590 * can zero it out to prevent faults on exit from the
591 * hypervisor if the next process has no %gs. Either way, it
592 * has been saved, and the new value will get loaded properly.
593 * This will go away as soon as Xen has been modified to not
594 * save/restore %gs for normal hypercalls.
596 * On x86_64, this hack is not used for %gs, because gs points
597 * to KERNEL_GS_BASE (and uses it for PDA references), so we
598 * must not zero %gs on x86_64
600 * For x86_64, we need to zero %fs, otherwise we may get an
601 * exception between the new %fs descriptor being loaded and
602 * %fs being effectively cleared at __switch_to().
604 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU
) {
614 load_TLS_descriptor(t
, cpu
, 0);
615 load_TLS_descriptor(t
, cpu
, 1);
616 load_TLS_descriptor(t
, cpu
, 2);
618 xen_mc_issue(PARAVIRT_LAZY_CPU
);
622 static void xen_load_gs_index(unsigned int idx
)
624 if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL
, idx
))
629 static void xen_write_ldt_entry(struct desc_struct
*dt
, int entrynum
,
632 xmaddr_t mach_lp
= arbitrary_virt_to_machine(&dt
[entrynum
]);
633 u64 entry
= *(u64
*)ptr
;
635 trace_xen_cpu_write_ldt_entry(dt
, entrynum
, entry
);
640 if (HYPERVISOR_update_descriptor(mach_lp
.maddr
, entry
))
646 static int cvt_gate_to_trap(int vector
, const gate_desc
*val
,
647 struct trap_info
*info
)
651 if (val
->type
!= GATE_TRAP
&& val
->type
!= GATE_INTERRUPT
)
654 info
->vector
= vector
;
656 addr
= gate_offset(*val
);
659 * Look for known traps using IST, and substitute them
660 * appropriately. The debugger ones are the only ones we care
661 * about. Xen will handle faults like double_fault,
662 * so we should never see them. Warn if
663 * there's an unexpected IST-using fault handler.
665 if (addr
== (unsigned long)debug
)
666 addr
= (unsigned long)xen_debug
;
667 else if (addr
== (unsigned long)int3
)
668 addr
= (unsigned long)xen_int3
;
669 else if (addr
== (unsigned long)stack_segment
)
670 addr
= (unsigned long)xen_stack_segment
;
671 else if (addr
== (unsigned long)double_fault
||
672 addr
== (unsigned long)nmi
) {
673 /* Don't need to handle these */
675 #ifdef CONFIG_X86_MCE
676 } else if (addr
== (unsigned long)machine_check
) {
678 * when xen hypervisor inject vMCE to guest,
679 * use native mce handler to handle it
684 /* Some other trap using IST? */
685 if (WARN_ON(val
->ist
!= 0))
688 #endif /* CONFIG_X86_64 */
689 info
->address
= addr
;
691 info
->cs
= gate_segment(*val
);
692 info
->flags
= val
->dpl
;
693 /* interrupt gates clear IF */
694 if (val
->type
== GATE_INTERRUPT
)
695 info
->flags
|= 1 << 2;
700 /* Locations of each CPU's IDT */
701 static DEFINE_PER_CPU(struct desc_ptr
, idt_desc
);
703 /* Set an IDT entry. If the entry is part of the current IDT, then
705 static void xen_write_idt_entry(gate_desc
*dt
, int entrynum
, const gate_desc
*g
)
707 unsigned long p
= (unsigned long)&dt
[entrynum
];
708 unsigned long start
, end
;
710 trace_xen_cpu_write_idt_entry(dt
, entrynum
, g
);
714 start
= __this_cpu_read(idt_desc
.address
);
715 end
= start
+ __this_cpu_read(idt_desc
.size
) + 1;
719 native_write_idt_entry(dt
, entrynum
, g
);
721 if (p
>= start
&& (p
+ 8) <= end
) {
722 struct trap_info info
[2];
726 if (cvt_gate_to_trap(entrynum
, g
, &info
[0]))
727 if (HYPERVISOR_set_trap_table(info
))
734 static void xen_convert_trap_info(const struct desc_ptr
*desc
,
735 struct trap_info
*traps
)
737 unsigned in
, out
, count
;
739 count
= (desc
->size
+1) / sizeof(gate_desc
);
742 for (in
= out
= 0; in
< count
; in
++) {
743 gate_desc
*entry
= (gate_desc
*)(desc
->address
) + in
;
745 if (cvt_gate_to_trap(in
, entry
, &traps
[out
]))
748 traps
[out
].address
= 0;
751 void xen_copy_trap_info(struct trap_info
*traps
)
753 const struct desc_ptr
*desc
= &__get_cpu_var(idt_desc
);
755 xen_convert_trap_info(desc
, traps
);
758 /* Load a new IDT into Xen. In principle this can be per-CPU, so we
759 hold a spinlock to protect the static traps[] array (static because
760 it avoids allocation, and saves stack space). */
761 static void xen_load_idt(const struct desc_ptr
*desc
)
763 static DEFINE_SPINLOCK(lock
);
764 static struct trap_info traps
[257];
766 trace_xen_cpu_load_idt(desc
);
770 __get_cpu_var(idt_desc
) = *desc
;
772 xen_convert_trap_info(desc
, traps
);
775 if (HYPERVISOR_set_trap_table(traps
))
781 /* Write a GDT descriptor entry. Ignore LDT descriptors, since
782 they're handled differently. */
783 static void xen_write_gdt_entry(struct desc_struct
*dt
, int entry
,
784 const void *desc
, int type
)
786 trace_xen_cpu_write_gdt_entry(dt
, entry
, desc
, type
);
797 xmaddr_t maddr
= arbitrary_virt_to_machine(&dt
[entry
]);
800 if (HYPERVISOR_update_descriptor(maddr
.maddr
, *(u64
*)desc
))
810 * Version of write_gdt_entry for use at early boot-time needed to
811 * update an entry as simply as possible.
813 static void __init
xen_write_gdt_entry_boot(struct desc_struct
*dt
, int entry
,
814 const void *desc
, int type
)
816 trace_xen_cpu_write_gdt_entry(dt
, entry
, desc
, type
);
825 xmaddr_t maddr
= virt_to_machine(&dt
[entry
]);
827 if (HYPERVISOR_update_descriptor(maddr
.maddr
, *(u64
*)desc
))
828 dt
[entry
] = *(struct desc_struct
*)desc
;
834 static void xen_load_sp0(struct tss_struct
*tss
,
835 struct thread_struct
*thread
)
837 struct multicall_space mcs
;
839 mcs
= xen_mc_entry(0);
840 MULTI_stack_switch(mcs
.mc
, __KERNEL_DS
, thread
->sp0
);
841 xen_mc_issue(PARAVIRT_LAZY_CPU
);
844 static void xen_set_iopl_mask(unsigned mask
)
846 struct physdev_set_iopl set_iopl
;
848 /* Force the change at ring 0. */
849 set_iopl
.iopl
= (mask
== 0) ? 1 : (mask
>> 12) & 3;
850 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl
, &set_iopl
);
853 static void xen_io_delay(void)
857 #ifdef CONFIG_X86_LOCAL_APIC
858 static unsigned long xen_set_apic_id(unsigned int x
)
863 static unsigned int xen_get_apic_id(unsigned long x
)
865 return ((x
)>>24) & 0xFFu
;
867 static u32
xen_apic_read(u32 reg
)
869 struct xen_platform_op op
= {
870 .cmd
= XENPF_get_cpuinfo
,
871 .interface_version
= XENPF_INTERFACE_VERSION
,
872 .u
.pcpu_info
.xen_cpuid
= 0,
876 /* Shouldn't need this as APIC is turned off for PV, and we only
877 * get called on the bootup processor. But just in case. */
878 if (!xen_initial_domain() || smp_processor_id())
887 ret
= HYPERVISOR_dom0_op(&op
);
891 return op
.u
.pcpu_info
.apic_id
<< 24;
894 static void xen_apic_write(u32 reg
, u32 val
)
896 /* Warn to see if there's any stray references */
900 static u64
xen_apic_icr_read(void)
905 static void xen_apic_icr_write(u32 low
, u32 id
)
907 /* Warn to see if there's any stray references */
911 static void xen_apic_wait_icr_idle(void)
916 static u32
xen_safe_apic_wait_icr_idle(void)
921 static void set_xen_basic_apic_ops(void)
923 apic
->read
= xen_apic_read
;
924 apic
->write
= xen_apic_write
;
925 apic
->icr_read
= xen_apic_icr_read
;
926 apic
->icr_write
= xen_apic_icr_write
;
927 apic
->wait_icr_idle
= xen_apic_wait_icr_idle
;
928 apic
->safe_wait_icr_idle
= xen_safe_apic_wait_icr_idle
;
929 apic
->set_apic_id
= xen_set_apic_id
;
930 apic
->get_apic_id
= xen_get_apic_id
;
933 apic
->send_IPI_allbutself
= xen_send_IPI_allbutself
;
934 apic
->send_IPI_mask_allbutself
= xen_send_IPI_mask_allbutself
;
935 apic
->send_IPI_mask
= xen_send_IPI_mask
;
936 apic
->send_IPI_all
= xen_send_IPI_all
;
937 apic
->send_IPI_self
= xen_send_IPI_self
;
943 static void xen_clts(void)
945 struct multicall_space mcs
;
947 mcs
= xen_mc_entry(0);
949 MULTI_fpu_taskswitch(mcs
.mc
, 0);
951 xen_mc_issue(PARAVIRT_LAZY_CPU
);
954 static DEFINE_PER_CPU(unsigned long, xen_cr0_value
);
956 static unsigned long xen_read_cr0(void)
958 unsigned long cr0
= this_cpu_read(xen_cr0_value
);
960 if (unlikely(cr0
== 0)) {
961 cr0
= native_read_cr0();
962 this_cpu_write(xen_cr0_value
, cr0
);
968 static void xen_write_cr0(unsigned long cr0
)
970 struct multicall_space mcs
;
972 this_cpu_write(xen_cr0_value
, cr0
);
974 /* Only pay attention to cr0.TS; everything else is
976 mcs
= xen_mc_entry(0);
978 MULTI_fpu_taskswitch(mcs
.mc
, (cr0
& X86_CR0_TS
) != 0);
980 xen_mc_issue(PARAVIRT_LAZY_CPU
);
983 static void xen_write_cr4(unsigned long cr4
)
988 native_write_cr4(cr4
);
991 static inline unsigned long xen_read_cr8(void)
995 static inline void xen_write_cr8(unsigned long val
)
1000 static int xen_write_msr_safe(unsigned int msr
, unsigned low
, unsigned high
)
1007 #ifdef CONFIG_X86_64
1011 case MSR_FS_BASE
: which
= SEGBASE_FS
; goto set
;
1012 case MSR_KERNEL_GS_BASE
: which
= SEGBASE_GS_USER
; goto set
;
1013 case MSR_GS_BASE
: which
= SEGBASE_GS_KERNEL
; goto set
;
1016 base
= ((u64
)high
<< 32) | low
;
1017 if (HYPERVISOR_set_segment_base(which
, base
) != 0)
1025 case MSR_SYSCALL_MASK
:
1026 case MSR_IA32_SYSENTER_CS
:
1027 case MSR_IA32_SYSENTER_ESP
:
1028 case MSR_IA32_SYSENTER_EIP
:
1029 /* Fast syscall setup is all done in hypercalls, so
1030 these are all ignored. Stub them out here to stop
1031 Xen console noise. */
1034 case MSR_IA32_CR_PAT
:
1035 if (smp_processor_id() == 0)
1036 xen_set_pat(((u64
)high
<< 32) | low
);
1040 ret
= native_write_msr_safe(msr
, low
, high
);
1046 void xen_setup_shared_info(void)
1048 if (!xen_feature(XENFEAT_auto_translated_physmap
)) {
1049 set_fixmap(FIX_PARAVIRT_BOOTMAP
,
1050 xen_start_info
->shared_info
);
1052 HYPERVISOR_shared_info
=
1053 (struct shared_info
*)fix_to_virt(FIX_PARAVIRT_BOOTMAP
);
1055 HYPERVISOR_shared_info
=
1056 (struct shared_info
*)__va(xen_start_info
->shared_info
);
1059 /* In UP this is as good a place as any to set up shared info */
1060 xen_setup_vcpu_info_placement();
1063 xen_setup_mfn_list_list();
1066 /* This is called once we have the cpu_possible_mask */
1067 void xen_setup_vcpu_info_placement(void)
1071 for_each_possible_cpu(cpu
)
1072 xen_vcpu_setup(cpu
);
1074 /* xen_vcpu_setup managed to place the vcpu_info within the
1075 percpu area for all cpus, so make use of it */
1076 if (have_vcpu_info_placement
) {
1077 pv_irq_ops
.save_fl
= __PV_IS_CALLEE_SAVE(xen_save_fl_direct
);
1078 pv_irq_ops
.restore_fl
= __PV_IS_CALLEE_SAVE(xen_restore_fl_direct
);
1079 pv_irq_ops
.irq_disable
= __PV_IS_CALLEE_SAVE(xen_irq_disable_direct
);
1080 pv_irq_ops
.irq_enable
= __PV_IS_CALLEE_SAVE(xen_irq_enable_direct
);
1081 pv_mmu_ops
.read_cr2
= xen_read_cr2_direct
;
1085 static unsigned xen_patch(u8 type
, u16 clobbers
, void *insnbuf
,
1086 unsigned long addr
, unsigned len
)
1088 char *start
, *end
, *reloc
;
1091 start
= end
= reloc
= NULL
;
1093 #define SITE(op, x) \
1094 case PARAVIRT_PATCH(op.x): \
1095 if (have_vcpu_info_placement) { \
1096 start = (char *)xen_##x##_direct; \
1097 end = xen_##x##_direct_end; \
1098 reloc = xen_##x##_direct_reloc; \
1103 SITE(pv_irq_ops
, irq_enable
);
1104 SITE(pv_irq_ops
, irq_disable
);
1105 SITE(pv_irq_ops
, save_fl
);
1106 SITE(pv_irq_ops
, restore_fl
);
1110 if (start
== NULL
|| (end
-start
) > len
)
1113 ret
= paravirt_patch_insns(insnbuf
, len
, start
, end
);
1115 /* Note: because reloc is assigned from something that
1116 appears to be an array, gcc assumes it's non-null,
1117 but doesn't know its relationship with start and
1119 if (reloc
> start
&& reloc
< end
) {
1120 int reloc_off
= reloc
- start
;
1121 long *relocp
= (long *)(insnbuf
+ reloc_off
);
1122 long delta
= start
- (char *)addr
;
1130 ret
= paravirt_patch_default(type
, clobbers
, insnbuf
,
1138 static const struct pv_info xen_info __initconst
= {
1139 .paravirt_enabled
= 1,
1140 .shared_kernel_pmd
= 0,
1142 #ifdef CONFIG_X86_64
1143 .extra_user_64bit_cs
= FLAT_USER_CS64
,
1149 static const struct pv_init_ops xen_init_ops __initconst
= {
1153 static const struct pv_cpu_ops xen_cpu_ops __initconst
= {
1156 .set_debugreg
= xen_set_debugreg
,
1157 .get_debugreg
= xen_get_debugreg
,
1161 .read_cr0
= xen_read_cr0
,
1162 .write_cr0
= xen_write_cr0
,
1164 .read_cr4
= native_read_cr4
,
1165 .read_cr4_safe
= native_read_cr4_safe
,
1166 .write_cr4
= xen_write_cr4
,
1168 #ifdef CONFIG_X86_64
1169 .read_cr8
= xen_read_cr8
,
1170 .write_cr8
= xen_write_cr8
,
1173 .wbinvd
= native_wbinvd
,
1175 .read_msr
= native_read_msr_safe
,
1176 .write_msr
= xen_write_msr_safe
,
1178 .read_tsc
= native_read_tsc
,
1179 .read_pmc
= native_read_pmc
,
1181 .read_tscp
= native_read_tscp
,
1184 .irq_enable_sysexit
= xen_sysexit
,
1185 #ifdef CONFIG_X86_64
1186 .usergs_sysret32
= xen_sysret32
,
1187 .usergs_sysret64
= xen_sysret64
,
1190 .load_tr_desc
= paravirt_nop
,
1191 .set_ldt
= xen_set_ldt
,
1192 .load_gdt
= xen_load_gdt
,
1193 .load_idt
= xen_load_idt
,
1194 .load_tls
= xen_load_tls
,
1195 #ifdef CONFIG_X86_64
1196 .load_gs_index
= xen_load_gs_index
,
1199 .alloc_ldt
= xen_alloc_ldt
,
1200 .free_ldt
= xen_free_ldt
,
1202 .store_gdt
= native_store_gdt
,
1203 .store_idt
= native_store_idt
,
1204 .store_tr
= xen_store_tr
,
1206 .write_ldt_entry
= xen_write_ldt_entry
,
1207 .write_gdt_entry
= xen_write_gdt_entry
,
1208 .write_idt_entry
= xen_write_idt_entry
,
1209 .load_sp0
= xen_load_sp0
,
1211 .set_iopl_mask
= xen_set_iopl_mask
,
1212 .io_delay
= xen_io_delay
,
1214 /* Xen takes care of %gs when switching to usermode for us */
1215 .swapgs
= paravirt_nop
,
1217 .start_context_switch
= paravirt_start_context_switch
,
1218 .end_context_switch
= xen_end_context_switch
,
1221 static const struct pv_apic_ops xen_apic_ops __initconst
= {
1222 #ifdef CONFIG_X86_LOCAL_APIC
1223 .startup_ipi_hook
= paravirt_nop
,
1227 static void xen_reboot(int reason
)
1229 struct sched_shutdown r
= { .reason
= reason
};
1231 if (HYPERVISOR_sched_op(SCHEDOP_shutdown
, &r
))
1235 static void xen_restart(char *msg
)
1237 xen_reboot(SHUTDOWN_reboot
);
1240 static void xen_emergency_restart(void)
1242 xen_reboot(SHUTDOWN_reboot
);
1245 static void xen_machine_halt(void)
1247 xen_reboot(SHUTDOWN_poweroff
);
1250 static void xen_machine_power_off(void)
1254 xen_reboot(SHUTDOWN_poweroff
);
1257 static void xen_crash_shutdown(struct pt_regs
*regs
)
1259 xen_reboot(SHUTDOWN_crash
);
1263 xen_panic_event(struct notifier_block
*this, unsigned long event
, void *ptr
)
1265 xen_reboot(SHUTDOWN_crash
);
1269 static struct notifier_block xen_panic_block
= {
1270 .notifier_call
= xen_panic_event
,
1273 int xen_panic_handler_init(void)
1275 atomic_notifier_chain_register(&panic_notifier_list
, &xen_panic_block
);
1279 static const struct machine_ops xen_machine_ops __initconst
= {
1280 .restart
= xen_restart
,
1281 .halt
= xen_machine_halt
,
1282 .power_off
= xen_machine_power_off
,
1283 .shutdown
= xen_machine_halt
,
1284 .crash_shutdown
= xen_crash_shutdown
,
1285 .emergency_restart
= xen_emergency_restart
,
1289 * Set up the GDT and segment registers for -fstack-protector. Until
1290 * we do this, we have to be careful not to call any stack-protected
1291 * function, which is most of the kernel.
1293 static void __init
xen_setup_stackprotector(void)
1295 pv_cpu_ops
.write_gdt_entry
= xen_write_gdt_entry_boot
;
1296 pv_cpu_ops
.load_gdt
= xen_load_gdt_boot
;
1298 setup_stack_canary_segment(0);
1299 switch_to_new_gdt(0);
1301 pv_cpu_ops
.write_gdt_entry
= xen_write_gdt_entry
;
1302 pv_cpu_ops
.load_gdt
= xen_load_gdt
;
1305 /* First C function to be called on Xen boot */
1306 asmlinkage
void __init
xen_start_kernel(void)
1308 struct physdev_set_iopl set_iopl
;
1311 if (!xen_start_info
)
1314 xen_domain_type
= XEN_PV_DOMAIN
;
1316 xen_setup_machphys_mapping();
1318 /* Install Xen paravirt ops */
1320 pv_init_ops
= xen_init_ops
;
1321 pv_cpu_ops
= xen_cpu_ops
;
1322 pv_apic_ops
= xen_apic_ops
;
1324 x86_init
.resources
.memory_setup
= xen_memory_setup
;
1325 x86_init
.oem
.arch_setup
= xen_arch_setup
;
1326 x86_init
.oem
.banner
= xen_banner
;
1328 xen_init_time_ops();
1331 * Set up some pagetable state before starting to set any ptes.
1336 /* Prevent unwanted bits from being set in PTEs. */
1337 __supported_pte_mask
&= ~_PAGE_GLOBAL
;
1339 if (!xen_initial_domain())
1341 __supported_pte_mask
&= ~(_PAGE_PWT
| _PAGE_PCD
);
1343 __supported_pte_mask
|= _PAGE_IOMAP
;
1346 * Prevent page tables from being allocated in highmem, even
1347 * if CONFIG_HIGHPTE is enabled.
1349 __userpte_alloc_gfp
&= ~__GFP_HIGHMEM
;
1351 /* Work out if we support NX */
1354 xen_setup_features();
1357 if (!xen_feature(XENFEAT_auto_translated_physmap
))
1358 xen_build_dynamic_phys_to_machine();
1361 * Set up kernel GDT and segment registers, mainly so that
1362 * -fstack-protector code can be executed.
1364 xen_setup_stackprotector();
1367 xen_init_cpuid_mask();
1369 #ifdef CONFIG_X86_LOCAL_APIC
1371 * set up the basic apic ops.
1373 set_xen_basic_apic_ops();
1376 if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad
)) {
1377 pv_mmu_ops
.ptep_modify_prot_start
= xen_ptep_modify_prot_start
;
1378 pv_mmu_ops
.ptep_modify_prot_commit
= xen_ptep_modify_prot_commit
;
1381 machine_ops
= xen_machine_ops
;
1384 * The only reliable way to retain the initial address of the
1385 * percpu gdt_page is to remember it here, so we can go and
1386 * mark it RW later, when the initial percpu area is freed.
1388 xen_initial_gdt
= &per_cpu(gdt_page
, 0);
1392 #ifdef CONFIG_ACPI_NUMA
1394 * The pages we from Xen are not related to machine pages, so
1395 * any NUMA information the kernel tries to get from ACPI will
1396 * be meaningless. Prevent it from trying.
1401 /* Don't do the full vcpu_info placement stuff until we have a
1402 possible map and a non-dummy shared_info. */
1403 per_cpu(xen_vcpu
, 0) = &HYPERVISOR_shared_info
->vcpu_info
[0];
1405 local_irq_disable();
1406 early_boot_irqs_disabled
= true;
1408 xen_raw_console_write("mapping kernel into physical memory\n");
1409 xen_setup_kernel_pagetable((pgd_t
*)xen_start_info
->pt_base
, xen_start_info
->nr_pages
);
1411 /* Allocate and initialize top and mid mfn levels for p2m structure */
1412 xen_build_mfn_list_list();
1414 /* keep using Xen gdt for now; no urgent need to change it */
1416 #ifdef CONFIG_X86_32
1417 pv_info
.kernel_rpl
= 1;
1418 if (xen_feature(XENFEAT_supervisor_mode_kernel
))
1419 pv_info
.kernel_rpl
= 0;
1421 pv_info
.kernel_rpl
= 0;
1423 /* set the limit of our address space */
1426 /* We used to do this in xen_arch_setup, but that is too late on AMD
1427 * were early_cpu_init (run before ->arch_setup()) calls early_amd_init
1428 * which pokes 0xcf8 port.
1431 rc
= HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl
, &set_iopl
);
1433 xen_raw_printk("physdev_op failed %d\n", rc
);
1435 #ifdef CONFIG_X86_32
1436 /* set up basic CPUID stuff */
1437 cpu_detect(&new_cpu_data
);
1438 new_cpu_data
.hard_math
= 1;
1439 new_cpu_data
.wp_works_ok
= 1;
1440 new_cpu_data
.x86_capability
[0] = cpuid_edx(1);
1443 /* Poke various useful things into boot_params */
1444 boot_params
.hdr
.type_of_loader
= (9 << 4) | 0;
1445 boot_params
.hdr
.ramdisk_image
= xen_start_info
->mod_start
1446 ? __pa(xen_start_info
->mod_start
) : 0;
1447 boot_params
.hdr
.ramdisk_size
= xen_start_info
->mod_len
;
1448 boot_params
.hdr
.cmd_line_ptr
= __pa(xen_start_info
->cmd_line
);
1450 if (!xen_initial_domain()) {
1451 add_preferred_console("xenboot", 0, NULL
);
1452 add_preferred_console("tty", 0, NULL
);
1453 add_preferred_console("hvc", 0, NULL
);
1455 x86_init
.pci
.arch_init
= pci_xen_init
;
1457 const struct dom0_vga_console_info
*info
=
1458 (void *)((char *)xen_start_info
+
1459 xen_start_info
->console
.dom0
.info_off
);
1460 struct xen_platform_op op
= {
1461 .cmd
= XENPF_firmware_info
,
1462 .interface_version
= XENPF_INTERFACE_VERSION
,
1463 .u
.firmware_info
.type
= XEN_FW_KBD_SHIFT_FLAGS
,
1466 xen_init_vga(info
, xen_start_info
->console
.dom0
.info_size
);
1467 xen_start_info
->console
.domU
.mfn
= 0;
1468 xen_start_info
->console
.domU
.evtchn
= 0;
1470 if (HYPERVISOR_dom0_op(&op
) == 0)
1471 boot_params
.kbd_status
= op
.u
.firmware_info
.u
.kbd_shift_flags
;
1475 /* Make sure ACS will be enabled */
1478 xen_acpi_sleep_register();
1480 /* Avoid searching for BIOS MP tables */
1481 x86_init
.mpparse
.find_smp_config
= x86_init_noop
;
1482 x86_init
.mpparse
.get_smp_config
= x86_init_uint_noop
;
1485 /* PCI BIOS service won't work from a PV guest. */
1486 pci_probe
&= ~PCI_PROBE_BIOS
;
1488 xen_raw_console_write("about to get started...\n");
1490 xen_setup_runstate_info(0);
1492 /* Start the world */
1493 #ifdef CONFIG_X86_32
1494 i386_start_kernel();
1496 x86_64_start_reservations((char *)__pa_symbol(&boot_params
));
1500 void __ref
xen_hvm_init_shared_info(void)
1503 struct xen_add_to_physmap xatp
;
1504 static struct shared_info
*shared_info_page
= 0;
1506 if (!shared_info_page
)
1507 shared_info_page
= (struct shared_info
*)
1508 extend_brk(PAGE_SIZE
, PAGE_SIZE
);
1509 xatp
.domid
= DOMID_SELF
;
1511 xatp
.space
= XENMAPSPACE_shared_info
;
1512 xatp
.gpfn
= __pa(shared_info_page
) >> PAGE_SHIFT
;
1513 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap
, &xatp
))
1516 HYPERVISOR_shared_info
= (struct shared_info
*)shared_info_page
;
1518 /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
1519 * page, we use it in the event channel upcall and in some pvclock
1520 * related functions. We don't need the vcpu_info placement
1521 * optimizations because we don't use any pv_mmu or pv_irq op on
1523 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
1524 * online but xen_hvm_init_shared_info is run at resume time too and
1525 * in that case multiple vcpus might be online. */
1526 for_each_online_cpu(cpu
) {
1527 per_cpu(xen_vcpu
, cpu
) = &HYPERVISOR_shared_info
->vcpu_info
[cpu
];
1531 #ifdef CONFIG_XEN_PVHVM
1532 static void __init
init_hvm_pv_info(void)
1535 uint32_t eax
, ebx
, ecx
, edx
, pages
, msr
, base
;
1538 base
= xen_cpuid_base();
1539 cpuid(base
+ 1, &eax
, &ebx
, &ecx
, &edx
);
1542 minor
= eax
& 0xffff;
1543 printk(KERN_INFO
"Xen version %d.%d.\n", major
, minor
);
1545 cpuid(base
+ 2, &pages
, &msr
, &ecx
, &edx
);
1547 pfn
= __pa(hypercall_page
);
1548 wrmsr_safe(msr
, (u32
)pfn
, (u32
)(pfn
>> 32));
1550 xen_setup_features();
1552 pv_info
.name
= "Xen HVM";
1554 xen_domain_type
= XEN_HVM_DOMAIN
;
1557 static int __cpuinit
xen_hvm_cpu_notify(struct notifier_block
*self
,
1558 unsigned long action
, void *hcpu
)
1560 int cpu
= (long)hcpu
;
1562 case CPU_UP_PREPARE
:
1563 xen_vcpu_setup(cpu
);
1564 if (xen_have_vector_callback
)
1565 xen_init_lock_cpu(cpu
);
1573 static struct notifier_block xen_hvm_cpu_notifier __cpuinitdata
= {
1574 .notifier_call
= xen_hvm_cpu_notify
,
1577 static void __init
xen_hvm_guest_init(void)
1581 xen_hvm_init_shared_info();
1583 if (xen_feature(XENFEAT_hvm_callback_vector
))
1584 xen_have_vector_callback
= 1;
1586 register_cpu_notifier(&xen_hvm_cpu_notifier
);
1587 xen_unplug_emulated_devices();
1588 x86_init
.irqs
.intr_init
= xen_init_IRQ
;
1589 xen_hvm_init_time_ops();
1590 xen_hvm_init_mmu_ops();
1593 static bool __init
xen_hvm_platform(void)
1595 if (xen_pv_domain())
1598 if (!xen_cpuid_base())
1604 bool xen_hvm_need_lapic(void)
1606 if (xen_pv_domain())
1608 if (!xen_hvm_domain())
1610 if (xen_feature(XENFEAT_hvm_pirqs
) && xen_have_vector_callback
)
1614 EXPORT_SYMBOL_GPL(xen_hvm_need_lapic
);
1616 const struct hypervisor_x86 x86_hyper_xen_hvm __refconst
= {
1618 .detect
= xen_hvm_platform
,
1619 .init_platform
= xen_hvm_guest_init
,
1621 EXPORT_SYMBOL(x86_hyper_xen_hvm
);