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/interface/xen.h>
37 #include <xen/interface/version.h>
38 #include <xen/interface/physdev.h>
39 #include <xen/interface/vcpu.h>
40 #include <xen/interface/memory.h>
41 #include <xen/features.h>
44 #include <xen/hvc-console.h>
46 #include <asm/paravirt.h>
49 #include <asm/xen/hypercall.h>
50 #include <asm/xen/hypervisor.h>
51 #include <asm/fixmap.h>
52 #include <asm/processor.h>
53 #include <asm/proto.h>
54 #include <asm/msr-index.h>
55 #include <asm/traps.h>
56 #include <asm/setup.h>
58 #include <asm/pgalloc.h>
59 #include <asm/pgtable.h>
60 #include <asm/tlbflush.h>
61 #include <asm/reboot.h>
62 #include <asm/stackprotector.h>
63 #include <asm/hypervisor.h>
67 #include "multicalls.h"
69 EXPORT_SYMBOL_GPL(hypercall_page
);
71 DEFINE_PER_CPU(struct vcpu_info
*, xen_vcpu
);
72 DEFINE_PER_CPU(struct vcpu_info
, xen_vcpu_info
);
74 enum xen_domain_type xen_domain_type
= XEN_NATIVE
;
75 EXPORT_SYMBOL_GPL(xen_domain_type
);
77 struct start_info
*xen_start_info
;
78 EXPORT_SYMBOL_GPL(xen_start_info
);
80 struct shared_info xen_dummy_shared_info
;
82 void *xen_initial_gdt
;
84 RESERVE_BRK(shared_info_page_brk
, PAGE_SIZE
);
85 __read_mostly
int xen_have_vector_callback
;
86 EXPORT_SYMBOL_GPL(xen_have_vector_callback
);
89 * Point at some empty memory to start with. We map the real shared_info
90 * page as soon as fixmap is up and running.
92 struct shared_info
*HYPERVISOR_shared_info
= (void *)&xen_dummy_shared_info
;
95 * Flag to determine whether vcpu info placement is available on all
96 * VCPUs. We assume it is to start with, and then set it to zero on
97 * the first failure. This is because it can succeed on some VCPUs
98 * and not others, since it can involve hypervisor memory allocation,
99 * or because the guest failed to guarantee all the appropriate
100 * constraints on all VCPUs (ie buffer can't cross a page boundary).
102 * Note that any particular CPU may be using a placed vcpu structure,
103 * but we can only optimise if the all are.
105 * 0: not available, 1: available
107 static int have_vcpu_info_placement
= 1;
109 static void clamp_max_cpus(void)
112 if (setup_max_cpus
> MAX_VIRT_CPUS
)
113 setup_max_cpus
= MAX_VIRT_CPUS
;
117 static void xen_vcpu_setup(int cpu
)
119 struct vcpu_register_vcpu_info info
;
121 struct vcpu_info
*vcpup
;
123 BUG_ON(HYPERVISOR_shared_info
== &xen_dummy_shared_info
);
125 if (cpu
< MAX_VIRT_CPUS
)
126 per_cpu(xen_vcpu
,cpu
) = &HYPERVISOR_shared_info
->vcpu_info
[cpu
];
128 if (!have_vcpu_info_placement
) {
129 if (cpu
>= MAX_VIRT_CPUS
)
134 vcpup
= &per_cpu(xen_vcpu_info
, cpu
);
135 info
.mfn
= arbitrary_virt_to_mfn(vcpup
);
136 info
.offset
= offset_in_page(vcpup
);
138 /* Check to see if the hypervisor will put the vcpu_info
139 structure where we want it, which allows direct access via
140 a percpu-variable. */
141 err
= HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info
, cpu
, &info
);
144 printk(KERN_DEBUG
"register_vcpu_info failed: err=%d\n", err
);
145 have_vcpu_info_placement
= 0;
148 /* This cpu is using the registered vcpu info, even if
149 later ones fail to. */
150 per_cpu(xen_vcpu
, cpu
) = vcpup
;
155 * On restore, set the vcpu placement up again.
156 * If it fails, then we're in a bad state, since
157 * we can't back out from using it...
159 void xen_vcpu_restore(void)
163 for_each_online_cpu(cpu
) {
164 bool other_cpu
= (cpu
!= smp_processor_id());
167 HYPERVISOR_vcpu_op(VCPUOP_down
, cpu
, NULL
))
170 xen_setup_runstate_info(cpu
);
172 if (have_vcpu_info_placement
)
176 HYPERVISOR_vcpu_op(VCPUOP_up
, cpu
, NULL
))
181 static void __init
xen_banner(void)
183 unsigned version
= HYPERVISOR_xen_version(XENVER_version
, NULL
);
184 struct xen_extraversion extra
;
185 HYPERVISOR_xen_version(XENVER_extraversion
, &extra
);
187 printk(KERN_INFO
"Booting paravirtualized kernel on %s\n",
189 printk(KERN_INFO
"Xen version: %d.%d%s%s\n",
190 version
>> 16, version
& 0xffff, extra
.extraversion
,
191 xen_feature(XENFEAT_mmu_pt_update_preserve_ad
) ? " (preserve-AD)" : "");
194 static __read_mostly
unsigned int cpuid_leaf1_edx_mask
= ~0;
195 static __read_mostly
unsigned int cpuid_leaf1_ecx_mask
= ~0;
197 static void xen_cpuid(unsigned int *ax
, unsigned int *bx
,
198 unsigned int *cx
, unsigned int *dx
)
200 unsigned maskebx
= ~0;
201 unsigned maskecx
= ~0;
202 unsigned maskedx
= ~0;
205 * Mask out inconvenient features, to try and disable as many
206 * unsupported kernel subsystems as possible.
210 maskecx
= cpuid_leaf1_ecx_mask
;
211 maskedx
= cpuid_leaf1_edx_mask
;
215 /* Suppress extended topology stuff */
220 asm(XEN_EMULATE_PREFIX
"cpuid"
225 : "0" (*ax
), "2" (*cx
));
232 static __init
void xen_init_cpuid_mask(void)
234 unsigned int ax
, bx
, cx
, dx
;
236 cpuid_leaf1_edx_mask
=
237 ~((1 << X86_FEATURE_MCE
) | /* disable MCE */
238 (1 << X86_FEATURE_MCA
) | /* disable MCA */
239 (1 << X86_FEATURE_ACC
)); /* thermal monitoring */
241 if (!xen_initial_domain())
242 cpuid_leaf1_edx_mask
&=
243 ~((1 << X86_FEATURE_APIC
) | /* disable local APIC */
244 (1 << X86_FEATURE_ACPI
)); /* disable ACPI */
248 xen_cpuid(&ax
, &bx
, &cx
, &dx
);
250 /* cpuid claims we support xsave; try enabling it to see what happens */
251 if (cx
& (1 << (X86_FEATURE_XSAVE
% 32))) {
254 set_in_cr4(X86_CR4_OSXSAVE
);
258 if ((cr4
& X86_CR4_OSXSAVE
) == 0)
259 cpuid_leaf1_ecx_mask
&= ~(1 << (X86_FEATURE_XSAVE
% 32));
261 clear_in_cr4(X86_CR4_OSXSAVE
);
265 static void xen_set_debugreg(int reg
, unsigned long val
)
267 HYPERVISOR_set_debugreg(reg
, val
);
270 static unsigned long xen_get_debugreg(int reg
)
272 return HYPERVISOR_get_debugreg(reg
);
275 static void xen_end_context_switch(struct task_struct
*next
)
278 paravirt_end_context_switch(next
);
281 static unsigned long xen_store_tr(void)
287 * Set the page permissions for a particular virtual address. If the
288 * address is a vmalloc mapping (or other non-linear mapping), then
289 * find the linear mapping of the page and also set its protections to
292 static void set_aliased_prot(void *v
, pgprot_t prot
)
300 ptep
= lookup_address((unsigned long)v
, &level
);
301 BUG_ON(ptep
== NULL
);
303 pfn
= pte_pfn(*ptep
);
304 page
= pfn_to_page(pfn
);
306 pte
= pfn_pte(pfn
, prot
);
308 if (HYPERVISOR_update_va_mapping((unsigned long)v
, pte
, 0))
311 if (!PageHighMem(page
)) {
312 void *av
= __va(PFN_PHYS(pfn
));
315 if (HYPERVISOR_update_va_mapping((unsigned long)av
, pte
, 0))
321 static void xen_alloc_ldt(struct desc_struct
*ldt
, unsigned entries
)
323 const unsigned entries_per_page
= PAGE_SIZE
/ LDT_ENTRY_SIZE
;
326 for(i
= 0; i
< entries
; i
+= entries_per_page
)
327 set_aliased_prot(ldt
+ i
, PAGE_KERNEL_RO
);
330 static void xen_free_ldt(struct desc_struct
*ldt
, unsigned entries
)
332 const unsigned entries_per_page
= PAGE_SIZE
/ LDT_ENTRY_SIZE
;
335 for(i
= 0; i
< entries
; i
+= entries_per_page
)
336 set_aliased_prot(ldt
+ i
, PAGE_KERNEL
);
339 static void xen_set_ldt(const void *addr
, unsigned entries
)
341 struct mmuext_op
*op
;
342 struct multicall_space mcs
= xen_mc_entry(sizeof(*op
));
345 op
->cmd
= MMUEXT_SET_LDT
;
346 op
->arg1
.linear_addr
= (unsigned long)addr
;
347 op
->arg2
.nr_ents
= entries
;
349 MULTI_mmuext_op(mcs
.mc
, op
, 1, NULL
, DOMID_SELF
);
351 xen_mc_issue(PARAVIRT_LAZY_CPU
);
354 static void xen_load_gdt(const struct desc_ptr
*dtr
)
356 unsigned long va
= dtr
->address
;
357 unsigned int size
= dtr
->size
+ 1;
358 unsigned pages
= (size
+ PAGE_SIZE
- 1) / PAGE_SIZE
;
359 unsigned long frames
[pages
];
363 * A GDT can be up to 64k in size, which corresponds to 8192
364 * 8-byte entries, or 16 4k pages..
367 BUG_ON(size
> 65536);
368 BUG_ON(va
& ~PAGE_MASK
);
370 for (f
= 0; va
< dtr
->address
+ size
; va
+= PAGE_SIZE
, f
++) {
373 unsigned long pfn
, mfn
;
377 * The GDT is per-cpu and is in the percpu data area.
378 * That can be virtually mapped, so we need to do a
379 * page-walk to get the underlying MFN for the
380 * hypercall. The page can also be in the kernel's
381 * linear range, so we need to RO that mapping too.
383 ptep
= lookup_address(va
, &level
);
384 BUG_ON(ptep
== NULL
);
386 pfn
= pte_pfn(*ptep
);
387 mfn
= pfn_to_mfn(pfn
);
388 virt
= __va(PFN_PHYS(pfn
));
392 make_lowmem_page_readonly((void *)va
);
393 make_lowmem_page_readonly(virt
);
396 if (HYPERVISOR_set_gdt(frames
, size
/ sizeof(struct desc_struct
)))
401 * load_gdt for early boot, when the gdt is only mapped once
403 static __init
void xen_load_gdt_boot(const struct desc_ptr
*dtr
)
405 unsigned long va
= dtr
->address
;
406 unsigned int size
= dtr
->size
+ 1;
407 unsigned pages
= (size
+ PAGE_SIZE
- 1) / PAGE_SIZE
;
408 unsigned long frames
[pages
];
412 * A GDT can be up to 64k in size, which corresponds to 8192
413 * 8-byte entries, or 16 4k pages..
416 BUG_ON(size
> 65536);
417 BUG_ON(va
& ~PAGE_MASK
);
419 for (f
= 0; va
< dtr
->address
+ size
; va
+= PAGE_SIZE
, f
++) {
421 unsigned long pfn
, mfn
;
423 pfn
= virt_to_pfn(va
);
424 mfn
= pfn_to_mfn(pfn
);
426 pte
= pfn_pte(pfn
, PAGE_KERNEL_RO
);
428 if (HYPERVISOR_update_va_mapping((unsigned long)va
, pte
, 0))
434 if (HYPERVISOR_set_gdt(frames
, size
/ sizeof(struct desc_struct
)))
438 static void load_TLS_descriptor(struct thread_struct
*t
,
439 unsigned int cpu
, unsigned int i
)
441 struct desc_struct
*gdt
= get_cpu_gdt_table(cpu
);
442 xmaddr_t maddr
= arbitrary_virt_to_machine(&gdt
[GDT_ENTRY_TLS_MIN
+i
]);
443 struct multicall_space mc
= __xen_mc_entry(0);
445 MULTI_update_descriptor(mc
.mc
, maddr
.maddr
, t
->tls_array
[i
]);
448 static void xen_load_tls(struct thread_struct
*t
, unsigned int cpu
)
451 * XXX sleazy hack: If we're being called in a lazy-cpu zone
452 * and lazy gs handling is enabled, it means we're in a
453 * context switch, and %gs has just been saved. This means we
454 * can zero it out to prevent faults on exit from the
455 * hypervisor if the next process has no %gs. Either way, it
456 * has been saved, and the new value will get loaded properly.
457 * This will go away as soon as Xen has been modified to not
458 * save/restore %gs for normal hypercalls.
460 * On x86_64, this hack is not used for %gs, because gs points
461 * to KERNEL_GS_BASE (and uses it for PDA references), so we
462 * must not zero %gs on x86_64
464 * For x86_64, we need to zero %fs, otherwise we may get an
465 * exception between the new %fs descriptor being loaded and
466 * %fs being effectively cleared at __switch_to().
468 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU
) {
478 load_TLS_descriptor(t
, cpu
, 0);
479 load_TLS_descriptor(t
, cpu
, 1);
480 load_TLS_descriptor(t
, cpu
, 2);
482 xen_mc_issue(PARAVIRT_LAZY_CPU
);
486 static void xen_load_gs_index(unsigned int idx
)
488 if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL
, idx
))
493 static void xen_write_ldt_entry(struct desc_struct
*dt
, int entrynum
,
496 xmaddr_t mach_lp
= arbitrary_virt_to_machine(&dt
[entrynum
]);
497 u64 entry
= *(u64
*)ptr
;
502 if (HYPERVISOR_update_descriptor(mach_lp
.maddr
, entry
))
508 static int cvt_gate_to_trap(int vector
, const gate_desc
*val
,
509 struct trap_info
*info
)
513 if (val
->type
!= GATE_TRAP
&& val
->type
!= GATE_INTERRUPT
)
516 info
->vector
= vector
;
518 addr
= gate_offset(*val
);
521 * Look for known traps using IST, and substitute them
522 * appropriately. The debugger ones are the only ones we care
523 * about. Xen will handle faults like double_fault and
524 * machine_check, so we should never see them. Warn if
525 * there's an unexpected IST-using fault handler.
527 if (addr
== (unsigned long)debug
)
528 addr
= (unsigned long)xen_debug
;
529 else if (addr
== (unsigned long)int3
)
530 addr
= (unsigned long)xen_int3
;
531 else if (addr
== (unsigned long)stack_segment
)
532 addr
= (unsigned long)xen_stack_segment
;
533 else if (addr
== (unsigned long)double_fault
||
534 addr
== (unsigned long)nmi
) {
535 /* Don't need to handle these */
537 #ifdef CONFIG_X86_MCE
538 } else if (addr
== (unsigned long)machine_check
) {
542 /* Some other trap using IST? */
543 if (WARN_ON(val
->ist
!= 0))
546 #endif /* CONFIG_X86_64 */
547 info
->address
= addr
;
549 info
->cs
= gate_segment(*val
);
550 info
->flags
= val
->dpl
;
551 /* interrupt gates clear IF */
552 if (val
->type
== GATE_INTERRUPT
)
553 info
->flags
|= 1 << 2;
558 /* Locations of each CPU's IDT */
559 static DEFINE_PER_CPU(struct desc_ptr
, idt_desc
);
561 /* Set an IDT entry. If the entry is part of the current IDT, then
563 static void xen_write_idt_entry(gate_desc
*dt
, int entrynum
, const gate_desc
*g
)
565 unsigned long p
= (unsigned long)&dt
[entrynum
];
566 unsigned long start
, end
;
570 start
= __get_cpu_var(idt_desc
).address
;
571 end
= start
+ __get_cpu_var(idt_desc
).size
+ 1;
575 native_write_idt_entry(dt
, entrynum
, g
);
577 if (p
>= start
&& (p
+ 8) <= end
) {
578 struct trap_info info
[2];
582 if (cvt_gate_to_trap(entrynum
, g
, &info
[0]))
583 if (HYPERVISOR_set_trap_table(info
))
590 static void xen_convert_trap_info(const struct desc_ptr
*desc
,
591 struct trap_info
*traps
)
593 unsigned in
, out
, count
;
595 count
= (desc
->size
+1) / sizeof(gate_desc
);
598 for (in
= out
= 0; in
< count
; in
++) {
599 gate_desc
*entry
= (gate_desc
*)(desc
->address
) + in
;
601 if (cvt_gate_to_trap(in
, entry
, &traps
[out
]))
604 traps
[out
].address
= 0;
607 void xen_copy_trap_info(struct trap_info
*traps
)
609 const struct desc_ptr
*desc
= &__get_cpu_var(idt_desc
);
611 xen_convert_trap_info(desc
, traps
);
614 /* Load a new IDT into Xen. In principle this can be per-CPU, so we
615 hold a spinlock to protect the static traps[] array (static because
616 it avoids allocation, and saves stack space). */
617 static void xen_load_idt(const struct desc_ptr
*desc
)
619 static DEFINE_SPINLOCK(lock
);
620 static struct trap_info traps
[257];
624 __get_cpu_var(idt_desc
) = *desc
;
626 xen_convert_trap_info(desc
, traps
);
629 if (HYPERVISOR_set_trap_table(traps
))
635 /* Write a GDT descriptor entry. Ignore LDT descriptors, since
636 they're handled differently. */
637 static void xen_write_gdt_entry(struct desc_struct
*dt
, int entry
,
638 const void *desc
, int type
)
649 xmaddr_t maddr
= arbitrary_virt_to_machine(&dt
[entry
]);
652 if (HYPERVISOR_update_descriptor(maddr
.maddr
, *(u64
*)desc
))
662 * Version of write_gdt_entry for use at early boot-time needed to
663 * update an entry as simply as possible.
665 static __init
void xen_write_gdt_entry_boot(struct desc_struct
*dt
, int entry
,
666 const void *desc
, int type
)
675 xmaddr_t maddr
= virt_to_machine(&dt
[entry
]);
677 if (HYPERVISOR_update_descriptor(maddr
.maddr
, *(u64
*)desc
))
678 dt
[entry
] = *(struct desc_struct
*)desc
;
684 static void xen_load_sp0(struct tss_struct
*tss
,
685 struct thread_struct
*thread
)
687 struct multicall_space mcs
= xen_mc_entry(0);
688 MULTI_stack_switch(mcs
.mc
, __KERNEL_DS
, thread
->sp0
);
689 xen_mc_issue(PARAVIRT_LAZY_CPU
);
692 static void xen_set_iopl_mask(unsigned mask
)
694 struct physdev_set_iopl set_iopl
;
696 /* Force the change at ring 0. */
697 set_iopl
.iopl
= (mask
== 0) ? 1 : (mask
>> 12) & 3;
698 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl
, &set_iopl
);
701 static void xen_io_delay(void)
705 #ifdef CONFIG_X86_LOCAL_APIC
706 static u32
xen_apic_read(u32 reg
)
711 static void xen_apic_write(u32 reg
, u32 val
)
713 /* Warn to see if there's any stray references */
717 static u64
xen_apic_icr_read(void)
722 static void xen_apic_icr_write(u32 low
, u32 id
)
724 /* Warn to see if there's any stray references */
728 static void xen_apic_wait_icr_idle(void)
733 static u32
xen_safe_apic_wait_icr_idle(void)
738 static void set_xen_basic_apic_ops(void)
740 apic
->read
= xen_apic_read
;
741 apic
->write
= xen_apic_write
;
742 apic
->icr_read
= xen_apic_icr_read
;
743 apic
->icr_write
= xen_apic_icr_write
;
744 apic
->wait_icr_idle
= xen_apic_wait_icr_idle
;
745 apic
->safe_wait_icr_idle
= xen_safe_apic_wait_icr_idle
;
750 static void xen_clts(void)
752 struct multicall_space mcs
;
754 mcs
= xen_mc_entry(0);
756 MULTI_fpu_taskswitch(mcs
.mc
, 0);
758 xen_mc_issue(PARAVIRT_LAZY_CPU
);
761 static DEFINE_PER_CPU(unsigned long, xen_cr0_value
);
763 static unsigned long xen_read_cr0(void)
765 unsigned long cr0
= percpu_read(xen_cr0_value
);
767 if (unlikely(cr0
== 0)) {
768 cr0
= native_read_cr0();
769 percpu_write(xen_cr0_value
, cr0
);
775 static void xen_write_cr0(unsigned long cr0
)
777 struct multicall_space mcs
;
779 percpu_write(xen_cr0_value
, cr0
);
781 /* Only pay attention to cr0.TS; everything else is
783 mcs
= xen_mc_entry(0);
785 MULTI_fpu_taskswitch(mcs
.mc
, (cr0
& X86_CR0_TS
) != 0);
787 xen_mc_issue(PARAVIRT_LAZY_CPU
);
790 static void xen_write_cr4(unsigned long cr4
)
795 native_write_cr4(cr4
);
798 static int xen_write_msr_safe(unsigned int msr
, unsigned low
, unsigned high
)
809 case MSR_FS_BASE
: which
= SEGBASE_FS
; goto set
;
810 case MSR_KERNEL_GS_BASE
: which
= SEGBASE_GS_USER
; goto set
;
811 case MSR_GS_BASE
: which
= SEGBASE_GS_KERNEL
; goto set
;
814 base
= ((u64
)high
<< 32) | low
;
815 if (HYPERVISOR_set_segment_base(which
, base
) != 0)
823 case MSR_SYSCALL_MASK
:
824 case MSR_IA32_SYSENTER_CS
:
825 case MSR_IA32_SYSENTER_ESP
:
826 case MSR_IA32_SYSENTER_EIP
:
827 /* Fast syscall setup is all done in hypercalls, so
828 these are all ignored. Stub them out here to stop
829 Xen console noise. */
832 case MSR_IA32_CR_PAT
:
833 if (smp_processor_id() == 0)
834 xen_set_pat(((u64
)high
<< 32) | low
);
838 ret
= native_write_msr_safe(msr
, low
, high
);
844 void xen_setup_shared_info(void)
846 if (!xen_feature(XENFEAT_auto_translated_physmap
)) {
847 set_fixmap(FIX_PARAVIRT_BOOTMAP
,
848 xen_start_info
->shared_info
);
850 HYPERVISOR_shared_info
=
851 (struct shared_info
*)fix_to_virt(FIX_PARAVIRT_BOOTMAP
);
853 HYPERVISOR_shared_info
=
854 (struct shared_info
*)__va(xen_start_info
->shared_info
);
857 /* In UP this is as good a place as any to set up shared info */
858 xen_setup_vcpu_info_placement();
861 xen_setup_mfn_list_list();
864 /* This is called once we have the cpu_possible_map */
865 void xen_setup_vcpu_info_placement(void)
869 for_each_possible_cpu(cpu
)
872 /* xen_vcpu_setup managed to place the vcpu_info within the
873 percpu area for all cpus, so make use of it */
874 if (have_vcpu_info_placement
) {
875 pv_irq_ops
.save_fl
= __PV_IS_CALLEE_SAVE(xen_save_fl_direct
);
876 pv_irq_ops
.restore_fl
= __PV_IS_CALLEE_SAVE(xen_restore_fl_direct
);
877 pv_irq_ops
.irq_disable
= __PV_IS_CALLEE_SAVE(xen_irq_disable_direct
);
878 pv_irq_ops
.irq_enable
= __PV_IS_CALLEE_SAVE(xen_irq_enable_direct
);
879 pv_mmu_ops
.read_cr2
= xen_read_cr2_direct
;
883 static unsigned xen_patch(u8 type
, u16 clobbers
, void *insnbuf
,
884 unsigned long addr
, unsigned len
)
886 char *start
, *end
, *reloc
;
889 start
= end
= reloc
= NULL
;
891 #define SITE(op, x) \
892 case PARAVIRT_PATCH(op.x): \
893 if (have_vcpu_info_placement) { \
894 start = (char *)xen_##x##_direct; \
895 end = xen_##x##_direct_end; \
896 reloc = xen_##x##_direct_reloc; \
901 SITE(pv_irq_ops
, irq_enable
);
902 SITE(pv_irq_ops
, irq_disable
);
903 SITE(pv_irq_ops
, save_fl
);
904 SITE(pv_irq_ops
, restore_fl
);
908 if (start
== NULL
|| (end
-start
) > len
)
911 ret
= paravirt_patch_insns(insnbuf
, len
, start
, end
);
913 /* Note: because reloc is assigned from something that
914 appears to be an array, gcc assumes it's non-null,
915 but doesn't know its relationship with start and
917 if (reloc
> start
&& reloc
< end
) {
918 int reloc_off
= reloc
- start
;
919 long *relocp
= (long *)(insnbuf
+ reloc_off
);
920 long delta
= start
- (char *)addr
;
928 ret
= paravirt_patch_default(type
, clobbers
, insnbuf
,
936 static const struct pv_info xen_info __initdata
= {
937 .paravirt_enabled
= 1,
938 .shared_kernel_pmd
= 0,
943 static const struct pv_init_ops xen_init_ops __initdata
= {
947 static const struct pv_cpu_ops xen_cpu_ops __initdata
= {
950 .set_debugreg
= xen_set_debugreg
,
951 .get_debugreg
= xen_get_debugreg
,
955 .read_cr0
= xen_read_cr0
,
956 .write_cr0
= xen_write_cr0
,
958 .read_cr4
= native_read_cr4
,
959 .read_cr4_safe
= native_read_cr4_safe
,
960 .write_cr4
= xen_write_cr4
,
962 .wbinvd
= native_wbinvd
,
964 .read_msr
= native_read_msr_safe
,
965 .write_msr
= xen_write_msr_safe
,
966 .read_tsc
= native_read_tsc
,
967 .read_pmc
= native_read_pmc
,
970 .irq_enable_sysexit
= xen_sysexit
,
972 .usergs_sysret32
= xen_sysret32
,
973 .usergs_sysret64
= xen_sysret64
,
976 .load_tr_desc
= paravirt_nop
,
977 .set_ldt
= xen_set_ldt
,
978 .load_gdt
= xen_load_gdt
,
979 .load_idt
= xen_load_idt
,
980 .load_tls
= xen_load_tls
,
982 .load_gs_index
= xen_load_gs_index
,
985 .alloc_ldt
= xen_alloc_ldt
,
986 .free_ldt
= xen_free_ldt
,
988 .store_gdt
= native_store_gdt
,
989 .store_idt
= native_store_idt
,
990 .store_tr
= xen_store_tr
,
992 .write_ldt_entry
= xen_write_ldt_entry
,
993 .write_gdt_entry
= xen_write_gdt_entry
,
994 .write_idt_entry
= xen_write_idt_entry
,
995 .load_sp0
= xen_load_sp0
,
997 .set_iopl_mask
= xen_set_iopl_mask
,
998 .io_delay
= xen_io_delay
,
1000 /* Xen takes care of %gs when switching to usermode for us */
1001 .swapgs
= paravirt_nop
,
1003 .start_context_switch
= paravirt_start_context_switch
,
1004 .end_context_switch
= xen_end_context_switch
,
1007 static const struct pv_apic_ops xen_apic_ops __initdata
= {
1008 #ifdef CONFIG_X86_LOCAL_APIC
1009 .startup_ipi_hook
= paravirt_nop
,
1013 static void xen_reboot(int reason
)
1015 struct sched_shutdown r
= { .reason
= reason
};
1021 if (HYPERVISOR_sched_op(SCHEDOP_shutdown
, &r
))
1025 static void xen_restart(char *msg
)
1027 xen_reboot(SHUTDOWN_reboot
);
1030 static void xen_emergency_restart(void)
1032 xen_reboot(SHUTDOWN_reboot
);
1035 static void xen_machine_halt(void)
1037 xen_reboot(SHUTDOWN_poweroff
);
1040 static void xen_crash_shutdown(struct pt_regs
*regs
)
1042 xen_reboot(SHUTDOWN_crash
);
1046 xen_panic_event(struct notifier_block
*this, unsigned long event
, void *ptr
)
1048 xen_reboot(SHUTDOWN_crash
);
1052 static struct notifier_block xen_panic_block
= {
1053 .notifier_call
= xen_panic_event
,
1056 int xen_panic_handler_init(void)
1058 atomic_notifier_chain_register(&panic_notifier_list
, &xen_panic_block
);
1062 static const struct machine_ops __initdata xen_machine_ops
= {
1063 .restart
= xen_restart
,
1064 .halt
= xen_machine_halt
,
1065 .power_off
= xen_machine_halt
,
1066 .shutdown
= xen_machine_halt
,
1067 .crash_shutdown
= xen_crash_shutdown
,
1068 .emergency_restart
= xen_emergency_restart
,
1072 * Set up the GDT and segment registers for -fstack-protector. Until
1073 * we do this, we have to be careful not to call any stack-protected
1074 * function, which is most of the kernel.
1076 static void __init
xen_setup_stackprotector(void)
1078 pv_cpu_ops
.write_gdt_entry
= xen_write_gdt_entry_boot
;
1079 pv_cpu_ops
.load_gdt
= xen_load_gdt_boot
;
1081 setup_stack_canary_segment(0);
1082 switch_to_new_gdt(0);
1084 pv_cpu_ops
.write_gdt_entry
= xen_write_gdt_entry
;
1085 pv_cpu_ops
.load_gdt
= xen_load_gdt
;
1088 /* First C function to be called on Xen boot */
1089 asmlinkage
void __init
xen_start_kernel(void)
1093 if (!xen_start_info
)
1096 xen_domain_type
= XEN_PV_DOMAIN
;
1098 /* Install Xen paravirt ops */
1100 pv_init_ops
= xen_init_ops
;
1101 pv_cpu_ops
= xen_cpu_ops
;
1102 pv_apic_ops
= xen_apic_ops
;
1104 x86_init
.resources
.memory_setup
= xen_memory_setup
;
1105 x86_init
.oem
.arch_setup
= xen_arch_setup
;
1106 x86_init
.oem
.banner
= xen_banner
;
1108 xen_init_time_ops();
1111 * Set up some pagetable state before starting to set any ptes.
1116 /* Prevent unwanted bits from being set in PTEs. */
1117 __supported_pte_mask
&= ~_PAGE_GLOBAL
;
1118 if (!xen_initial_domain())
1119 __supported_pte_mask
&= ~(_PAGE_PWT
| _PAGE_PCD
);
1121 __supported_pte_mask
|= _PAGE_IOMAP
;
1124 * Prevent page tables from being allocated in highmem, even
1125 * if CONFIG_HIGHPTE is enabled.
1127 __userpte_alloc_gfp
&= ~__GFP_HIGHMEM
;
1129 /* Work out if we support NX */
1132 xen_setup_features();
1135 if (!xen_feature(XENFEAT_auto_translated_physmap
))
1136 xen_build_dynamic_phys_to_machine();
1139 * Set up kernel GDT and segment registers, mainly so that
1140 * -fstack-protector code can be executed.
1142 xen_setup_stackprotector();
1145 xen_init_cpuid_mask();
1147 #ifdef CONFIG_X86_LOCAL_APIC
1149 * set up the basic apic ops.
1151 set_xen_basic_apic_ops();
1154 if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad
)) {
1155 pv_mmu_ops
.ptep_modify_prot_start
= xen_ptep_modify_prot_start
;
1156 pv_mmu_ops
.ptep_modify_prot_commit
= xen_ptep_modify_prot_commit
;
1159 machine_ops
= xen_machine_ops
;
1162 * The only reliable way to retain the initial address of the
1163 * percpu gdt_page is to remember it here, so we can go and
1164 * mark it RW later, when the initial percpu area is freed.
1166 xen_initial_gdt
= &per_cpu(gdt_page
, 0);
1170 pgd
= (pgd_t
*)xen_start_info
->pt_base
;
1172 if (!xen_initial_domain())
1173 __supported_pte_mask
&= ~(_PAGE_PWT
| _PAGE_PCD
);
1175 __supported_pte_mask
|= _PAGE_IOMAP
;
1176 /* Don't do the full vcpu_info placement stuff until we have a
1177 possible map and a non-dummy shared_info. */
1178 per_cpu(xen_vcpu
, 0) = &HYPERVISOR_shared_info
->vcpu_info
[0];
1180 local_irq_disable();
1181 early_boot_irqs_off();
1185 xen_raw_console_write("mapping kernel into physical memory\n");
1186 pgd
= xen_setup_kernel_pagetable(pgd
, xen_start_info
->nr_pages
);
1188 /* Allocate and initialize top and mid mfn levels for p2m structure */
1189 xen_build_mfn_list_list();
1193 /* keep using Xen gdt for now; no urgent need to change it */
1195 #ifdef CONFIG_X86_32
1196 pv_info
.kernel_rpl
= 1;
1197 if (xen_feature(XENFEAT_supervisor_mode_kernel
))
1198 pv_info
.kernel_rpl
= 0;
1200 pv_info
.kernel_rpl
= 0;
1203 /* set the limit of our address space */
1206 #ifdef CONFIG_X86_32
1207 /* set up basic CPUID stuff */
1208 cpu_detect(&new_cpu_data
);
1209 new_cpu_data
.hard_math
= 1;
1210 new_cpu_data
.wp_works_ok
= 1;
1211 new_cpu_data
.x86_capability
[0] = cpuid_edx(1);
1214 /* Poke various useful things into boot_params */
1215 boot_params
.hdr
.type_of_loader
= (9 << 4) | 0;
1216 boot_params
.hdr
.ramdisk_image
= xen_start_info
->mod_start
1217 ? __pa(xen_start_info
->mod_start
) : 0;
1218 boot_params
.hdr
.ramdisk_size
= xen_start_info
->mod_len
;
1219 boot_params
.hdr
.cmd_line_ptr
= __pa(xen_start_info
->cmd_line
);
1221 if (!xen_initial_domain()) {
1222 add_preferred_console("xenboot", 0, NULL
);
1223 add_preferred_console("tty", 0, NULL
);
1224 add_preferred_console("hvc", 0, NULL
);
1226 /* Make sure ACS will be enabled */
1231 xen_raw_console_write("about to get started...\n");
1233 xen_setup_runstate_info(0);
1235 /* Start the world */
1236 #ifdef CONFIG_X86_32
1237 i386_start_kernel();
1239 x86_64_start_reservations((char *)__pa_symbol(&boot_params
));
1243 static uint32_t xen_cpuid_base(void)
1245 uint32_t base
, eax
, ebx
, ecx
, edx
;
1248 for (base
= 0x40000000; base
< 0x40010000; base
+= 0x100) {
1249 cpuid(base
, &eax
, &ebx
, &ecx
, &edx
);
1250 *(uint32_t *)(signature
+ 0) = ebx
;
1251 *(uint32_t *)(signature
+ 4) = ecx
;
1252 *(uint32_t *)(signature
+ 8) = edx
;
1255 if (!strcmp("XenVMMXenVMM", signature
) && ((eax
- base
) >= 2))
1262 static int init_hvm_pv_info(int *major
, int *minor
)
1264 uint32_t eax
, ebx
, ecx
, edx
, pages
, msr
, base
;
1267 base
= xen_cpuid_base();
1268 cpuid(base
+ 1, &eax
, &ebx
, &ecx
, &edx
);
1271 *minor
= eax
& 0xffff;
1272 printk(KERN_INFO
"Xen version %d.%d.\n", *major
, *minor
);
1274 cpuid(base
+ 2, &pages
, &msr
, &ecx
, &edx
);
1276 pfn
= __pa(hypercall_page
);
1277 wrmsr_safe(msr
, (u32
)pfn
, (u32
)(pfn
>> 32));
1279 xen_setup_features();
1282 pv_info
.kernel_rpl
= 0;
1284 xen_domain_type
= XEN_HVM_DOMAIN
;
1289 void xen_hvm_init_shared_info(void)
1292 struct xen_add_to_physmap xatp
;
1293 static struct shared_info
*shared_info_page
= 0;
1295 if (!shared_info_page
)
1296 shared_info_page
= (struct shared_info
*)
1297 extend_brk(PAGE_SIZE
, PAGE_SIZE
);
1298 xatp
.domid
= DOMID_SELF
;
1300 xatp
.space
= XENMAPSPACE_shared_info
;
1301 xatp
.gpfn
= __pa(shared_info_page
) >> PAGE_SHIFT
;
1302 if (HYPERVISOR_memory_op(XENMEM_add_to_physmap
, &xatp
))
1305 HYPERVISOR_shared_info
= (struct shared_info
*)shared_info_page
;
1307 /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
1308 * page, we use it in the event channel upcall and in some pvclock
1309 * related functions. We don't need the vcpu_info placement
1310 * optimizations because we don't use any pv_mmu or pv_irq op on
1312 * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
1313 * online but xen_hvm_init_shared_info is run at resume time too and
1314 * in that case multiple vcpus might be online. */
1315 for_each_online_cpu(cpu
) {
1316 per_cpu(xen_vcpu
, cpu
) = &HYPERVISOR_shared_info
->vcpu_info
[cpu
];
1320 #ifdef CONFIG_XEN_PVHVM
1321 static int __cpuinit
xen_hvm_cpu_notify(struct notifier_block
*self
,
1322 unsigned long action
, void *hcpu
)
1324 int cpu
= (long)hcpu
;
1326 case CPU_UP_PREPARE
:
1327 per_cpu(xen_vcpu
, cpu
) = &HYPERVISOR_shared_info
->vcpu_info
[cpu
];
1335 static struct notifier_block __cpuinitdata xen_hvm_cpu_notifier
= {
1336 .notifier_call
= xen_hvm_cpu_notify
,
1339 static void __init
xen_hvm_guest_init(void)
1344 r
= init_hvm_pv_info(&major
, &minor
);
1348 xen_hvm_init_shared_info();
1350 if (xen_feature(XENFEAT_hvm_callback_vector
))
1351 xen_have_vector_callback
= 1;
1352 register_cpu_notifier(&xen_hvm_cpu_notifier
);
1353 xen_unplug_emulated_devices();
1354 have_vcpu_info_placement
= 0;
1355 x86_init
.irqs
.intr_init
= xen_init_IRQ
;
1356 xen_hvm_init_time_ops();
1357 xen_hvm_init_mmu_ops();
1360 static bool __init
xen_hvm_platform(void)
1362 if (xen_pv_domain())
1365 if (!xen_cpuid_base())
1371 const __refconst
struct hypervisor_x86 x86_hyper_xen_hvm
= {
1373 .detect
= xen_hvm_platform
,
1374 .init_platform
= xen_hvm_guest_init
,
1376 EXPORT_SYMBOL(x86_hyper_xen_hvm
);