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/kernel.h>
15 #include <linux/init.h>
16 #include <linux/smp.h>
17 #include <linux/preempt.h>
18 #include <linux/hardirq.h>
19 #include <linux/percpu.h>
20 #include <linux/delay.h>
21 #include <linux/start_kernel.h>
22 #include <linux/sched.h>
23 #include <linux/bootmem.h>
24 #include <linux/module.h>
26 #include <linux/page-flags.h>
27 #include <linux/highmem.h>
28 #include <linux/console.h>
30 #include <xen/interface/xen.h>
31 #include <xen/interface/physdev.h>
32 #include <xen/interface/vcpu.h>
33 #include <xen/interface/sched.h>
34 #include <xen/features.h>
37 #include <asm/paravirt.h>
39 #include <asm/xen/hypercall.h>
40 #include <asm/xen/hypervisor.h>
41 #include <asm/fixmap.h>
42 #include <asm/processor.h>
43 #include <asm/setup.h>
45 #include <asm/pgtable.h>
46 #include <asm/tlbflush.h>
47 #include <asm/reboot.h>
51 #include "multicalls.h"
53 EXPORT_SYMBOL_GPL(hypercall_page
);
55 DEFINE_PER_CPU(struct vcpu_info
*, xen_vcpu
);
56 DEFINE_PER_CPU(struct vcpu_info
, xen_vcpu_info
);
59 * Note about cr3 (pagetable base) values:
61 * xen_cr3 contains the current logical cr3 value; it contains the
62 * last set cr3. This may not be the current effective cr3, because
63 * its update may be being lazily deferred. However, a vcpu looking
64 * at its own cr3 can use this value knowing that it everything will
67 * xen_current_cr3 contains the actual vcpu cr3; it is set once the
68 * hypercall to set the vcpu cr3 is complete (so it may be a little
69 * out of date, but it will never be set early). If one vcpu is
70 * looking at another vcpu's cr3 value, it should use this variable.
72 DEFINE_PER_CPU(unsigned long, xen_cr3
); /* cr3 stored as physaddr */
73 DEFINE_PER_CPU(unsigned long, xen_current_cr3
); /* actual vcpu cr3 */
75 struct start_info
*xen_start_info
;
76 EXPORT_SYMBOL_GPL(xen_start_info
);
78 static /* __initdata */ struct shared_info dummy_shared_info
;
81 * Point at some empty memory to start with. We map the real shared_info
82 * page as soon as fixmap is up and running.
84 struct shared_info
*HYPERVISOR_shared_info
= (void *)&dummy_shared_info
;
87 * Flag to determine whether vcpu info placement is available on all
88 * VCPUs. We assume it is to start with, and then set it to zero on
89 * the first failure. This is because it can succeed on some VCPUs
90 * and not others, since it can involve hypervisor memory allocation,
91 * or because the guest failed to guarantee all the appropriate
92 * constraints on all VCPUs (ie buffer can't cross a page boundary).
94 * Note that any particular CPU may be using a placed vcpu structure,
95 * but we can only optimise if the all are.
97 * 0: not available, 1: available
99 static int have_vcpu_info_placement
= 1;
101 static void __init
xen_vcpu_setup(int cpu
)
103 struct vcpu_register_vcpu_info info
;
105 struct vcpu_info
*vcpup
;
107 BUG_ON(HYPERVISOR_shared_info
== &dummy_shared_info
);
108 per_cpu(xen_vcpu
, cpu
) = &HYPERVISOR_shared_info
->vcpu_info
[cpu
];
110 if (!have_vcpu_info_placement
)
111 return; /* already tested, not available */
113 vcpup
= &per_cpu(xen_vcpu_info
, cpu
);
115 info
.mfn
= virt_to_mfn(vcpup
);
116 info
.offset
= offset_in_page(vcpup
);
118 printk(KERN_DEBUG
"trying to map vcpu_info %d at %p, mfn %llx, offset %d\n",
119 cpu
, vcpup
, info
.mfn
, info
.offset
);
121 /* Check to see if the hypervisor will put the vcpu_info
122 structure where we want it, which allows direct access via
123 a percpu-variable. */
124 err
= HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info
, cpu
, &info
);
127 printk(KERN_DEBUG
"register_vcpu_info failed: err=%d\n", err
);
128 have_vcpu_info_placement
= 0;
130 /* This cpu is using the registered vcpu info, even if
131 later ones fail to. */
132 per_cpu(xen_vcpu
, cpu
) = vcpup
;
134 printk(KERN_DEBUG
"cpu %d using vcpu_info at %p\n",
139 static void __init
xen_banner(void)
141 printk(KERN_INFO
"Booting paravirtualized kernel on %s\n",
143 printk(KERN_INFO
"Hypervisor signature: %s\n", xen_start_info
->magic
);
146 static void xen_cpuid(unsigned int *ax
, unsigned int *bx
,
147 unsigned int *cx
, unsigned int *dx
)
149 unsigned maskedx
= ~0;
152 * Mask out inconvenient features, to try and disable as many
153 * unsupported kernel subsystems as possible.
156 maskedx
= ~((1 << X86_FEATURE_APIC
) | /* disable APIC */
157 (1 << X86_FEATURE_ACPI
) | /* disable ACPI */
158 (1 << X86_FEATURE_MCE
) | /* disable MCE */
159 (1 << X86_FEATURE_MCA
) | /* disable MCA */
160 (1 << X86_FEATURE_ACC
)); /* thermal monitoring */
162 asm(XEN_EMULATE_PREFIX
"cpuid"
167 : "0" (*ax
), "2" (*cx
));
171 static void xen_set_debugreg(int reg
, unsigned long val
)
173 HYPERVISOR_set_debugreg(reg
, val
);
176 static unsigned long xen_get_debugreg(int reg
)
178 return HYPERVISOR_get_debugreg(reg
);
181 static unsigned long xen_save_fl(void)
183 struct vcpu_info
*vcpu
;
186 vcpu
= x86_read_percpu(xen_vcpu
);
188 /* flag has opposite sense of mask */
189 flags
= !vcpu
->evtchn_upcall_mask
;
191 /* convert to IF type flag
195 return (-flags
) & X86_EFLAGS_IF
;
198 static void xen_restore_fl(unsigned long flags
)
200 struct vcpu_info
*vcpu
;
202 /* convert from IF type flag */
203 flags
= !(flags
& X86_EFLAGS_IF
);
205 /* There's a one instruction preempt window here. We need to
206 make sure we're don't switch CPUs between getting the vcpu
207 pointer and updating the mask. */
209 vcpu
= x86_read_percpu(xen_vcpu
);
210 vcpu
->evtchn_upcall_mask
= flags
;
211 preempt_enable_no_resched();
213 /* Doesn't matter if we get preempted here, because any
214 pending event will get dealt with anyway. */
217 preempt_check_resched();
218 barrier(); /* unmask then check (avoid races) */
219 if (unlikely(vcpu
->evtchn_upcall_pending
))
220 force_evtchn_callback();
224 static void xen_irq_disable(void)
226 /* There's a one instruction preempt window here. We need to
227 make sure we're don't switch CPUs between getting the vcpu
228 pointer and updating the mask. */
230 x86_read_percpu(xen_vcpu
)->evtchn_upcall_mask
= 1;
231 preempt_enable_no_resched();
234 static void xen_irq_enable(void)
236 struct vcpu_info
*vcpu
;
238 /* There's a one instruction preempt window here. We need to
239 make sure we're don't switch CPUs between getting the vcpu
240 pointer and updating the mask. */
242 vcpu
= x86_read_percpu(xen_vcpu
);
243 vcpu
->evtchn_upcall_mask
= 0;
244 preempt_enable_no_resched();
246 /* Doesn't matter if we get preempted here, because any
247 pending event will get dealt with anyway. */
249 barrier(); /* unmask then check (avoid races) */
250 if (unlikely(vcpu
->evtchn_upcall_pending
))
251 force_evtchn_callback();
254 static void xen_safe_halt(void)
256 /* Blocking includes an implicit local_irq_enable(). */
257 if (HYPERVISOR_sched_op(SCHEDOP_block
, 0) != 0)
261 static void xen_halt(void)
264 HYPERVISOR_vcpu_op(VCPUOP_down
, smp_processor_id(), NULL
);
269 static void xen_leave_lazy(void)
271 paravirt_leave_lazy(paravirt_get_lazy_mode());
275 static unsigned long xen_store_tr(void)
280 static void xen_set_ldt(const void *addr
, unsigned entries
)
282 struct mmuext_op
*op
;
283 struct multicall_space mcs
= xen_mc_entry(sizeof(*op
));
286 op
->cmd
= MMUEXT_SET_LDT
;
287 op
->arg1
.linear_addr
= (unsigned long)addr
;
288 op
->arg2
.nr_ents
= entries
;
290 MULTI_mmuext_op(mcs
.mc
, op
, 1, NULL
, DOMID_SELF
);
292 xen_mc_issue(PARAVIRT_LAZY_CPU
);
295 static void xen_load_gdt(const struct desc_ptr
*dtr
)
297 unsigned long *frames
;
298 unsigned long va
= dtr
->address
;
299 unsigned int size
= dtr
->size
+ 1;
300 unsigned pages
= (size
+ PAGE_SIZE
- 1) / PAGE_SIZE
;
302 struct multicall_space mcs
;
304 /* A GDT can be up to 64k in size, which corresponds to 8192
305 8-byte entries, or 16 4k pages.. */
307 BUG_ON(size
> 65536);
308 BUG_ON(va
& ~PAGE_MASK
);
310 mcs
= xen_mc_entry(sizeof(*frames
) * pages
);
313 for (f
= 0; va
< dtr
->address
+ size
; va
+= PAGE_SIZE
, f
++) {
314 frames
[f
] = virt_to_mfn(va
);
315 make_lowmem_page_readonly((void *)va
);
318 MULTI_set_gdt(mcs
.mc
, frames
, size
/ sizeof(struct desc_struct
));
320 xen_mc_issue(PARAVIRT_LAZY_CPU
);
323 static void load_TLS_descriptor(struct thread_struct
*t
,
324 unsigned int cpu
, unsigned int i
)
326 struct desc_struct
*gdt
= get_cpu_gdt_table(cpu
);
327 xmaddr_t maddr
= virt_to_machine(&gdt
[GDT_ENTRY_TLS_MIN
+i
]);
328 struct multicall_space mc
= __xen_mc_entry(0);
330 MULTI_update_descriptor(mc
.mc
, maddr
.maddr
, t
->tls_array
[i
]);
333 static void xen_load_tls(struct thread_struct
*t
, unsigned int cpu
)
337 load_TLS_descriptor(t
, cpu
, 0);
338 load_TLS_descriptor(t
, cpu
, 1);
339 load_TLS_descriptor(t
, cpu
, 2);
341 xen_mc_issue(PARAVIRT_LAZY_CPU
);
344 * XXX sleazy hack: If we're being called in a lazy-cpu zone,
345 * it means we're in a context switch, and %gs has just been
346 * saved. This means we can zero it out to prevent faults on
347 * exit from the hypervisor if the next process has no %gs.
348 * Either way, it has been saved, and the new value will get
349 * loaded properly. This will go away as soon as Xen has been
350 * modified to not save/restore %gs for normal hypercalls.
352 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU
)
356 static void xen_write_ldt_entry(struct desc_struct
*dt
, int entrynum
,
359 unsigned long lp
= (unsigned long)&dt
[entrynum
];
360 xmaddr_t mach_lp
= virt_to_machine(lp
);
361 u64 entry
= *(u64
*)ptr
;
366 if (HYPERVISOR_update_descriptor(mach_lp
.maddr
, entry
))
372 static int cvt_gate_to_trap(int vector
, u32 low
, u32 high
,
373 struct trap_info
*info
)
377 type
= (high
>> 8) & 0x1f;
378 dpl
= (high
>> 13) & 3;
380 if (type
!= 0xf && type
!= 0xe)
383 info
->vector
= vector
;
384 info
->address
= (high
& 0xffff0000) | (low
& 0x0000ffff);
385 info
->cs
= low
>> 16;
387 /* interrupt gates clear IF */
394 /* Locations of each CPU's IDT */
395 static DEFINE_PER_CPU(struct desc_ptr
, idt_desc
);
397 /* Set an IDT entry. If the entry is part of the current IDT, then
399 static void xen_write_idt_entry(gate_desc
*dt
, int entrynum
, const gate_desc
*g
)
401 unsigned long p
= (unsigned long)&dt
[entrynum
];
402 unsigned long start
, end
;
406 start
= __get_cpu_var(idt_desc
).address
;
407 end
= start
+ __get_cpu_var(idt_desc
).size
+ 1;
411 native_write_idt_entry(dt
, entrynum
, g
);
413 if (p
>= start
&& (p
+ 8) <= end
) {
414 struct trap_info info
[2];
415 u32
*desc
= (u32
*)g
;
419 if (cvt_gate_to_trap(entrynum
, desc
[0], desc
[1], &info
[0]))
420 if (HYPERVISOR_set_trap_table(info
))
427 static void xen_convert_trap_info(const struct desc_ptr
*desc
,
428 struct trap_info
*traps
)
430 unsigned in
, out
, count
;
432 count
= (desc
->size
+1) / 8;
435 for (in
= out
= 0; in
< count
; in
++) {
436 const u32
*entry
= (u32
*)(desc
->address
+ in
* 8);
438 if (cvt_gate_to_trap(in
, entry
[0], entry
[1], &traps
[out
]))
441 traps
[out
].address
= 0;
444 void xen_copy_trap_info(struct trap_info
*traps
)
446 const struct desc_ptr
*desc
= &__get_cpu_var(idt_desc
);
448 xen_convert_trap_info(desc
, traps
);
451 /* Load a new IDT into Xen. In principle this can be per-CPU, so we
452 hold a spinlock to protect the static traps[] array (static because
453 it avoids allocation, and saves stack space). */
454 static void xen_load_idt(const struct desc_ptr
*desc
)
456 static DEFINE_SPINLOCK(lock
);
457 static struct trap_info traps
[257];
461 __get_cpu_var(idt_desc
) = *desc
;
463 xen_convert_trap_info(desc
, traps
);
466 if (HYPERVISOR_set_trap_table(traps
))
472 /* Write a GDT descriptor entry. Ignore LDT descriptors, since
473 they're handled differently. */
474 static void xen_write_gdt_entry(struct desc_struct
*dt
, int entry
,
475 const void *desc
, int type
)
486 xmaddr_t maddr
= virt_to_machine(&dt
[entry
]);
489 if (HYPERVISOR_update_descriptor(maddr
.maddr
, *(u64
*)desc
))
498 static void xen_load_sp0(struct tss_struct
*tss
,
499 struct thread_struct
*thread
)
501 struct multicall_space mcs
= xen_mc_entry(0);
502 MULTI_stack_switch(mcs
.mc
, __KERNEL_DS
, thread
->sp0
);
503 xen_mc_issue(PARAVIRT_LAZY_CPU
);
506 static void xen_set_iopl_mask(unsigned mask
)
508 struct physdev_set_iopl set_iopl
;
510 /* Force the change at ring 0. */
511 set_iopl
.iopl
= (mask
== 0) ? 1 : (mask
>> 12) & 3;
512 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl
, &set_iopl
);
515 static void xen_io_delay(void)
519 #ifdef CONFIG_X86_LOCAL_APIC
520 static u32
xen_apic_read(unsigned long reg
)
525 static void xen_apic_write(unsigned long reg
, u32 val
)
527 /* Warn to see if there's any stray references */
532 static void xen_flush_tlb(void)
534 struct mmuext_op
*op
;
535 struct multicall_space mcs
;
539 mcs
= xen_mc_entry(sizeof(*op
));
542 op
->cmd
= MMUEXT_TLB_FLUSH_LOCAL
;
543 MULTI_mmuext_op(mcs
.mc
, op
, 1, NULL
, DOMID_SELF
);
545 xen_mc_issue(PARAVIRT_LAZY_MMU
);
550 static void xen_flush_tlb_single(unsigned long addr
)
552 struct mmuext_op
*op
;
553 struct multicall_space mcs
;
557 mcs
= xen_mc_entry(sizeof(*op
));
559 op
->cmd
= MMUEXT_INVLPG_LOCAL
;
560 op
->arg1
.linear_addr
= addr
& PAGE_MASK
;
561 MULTI_mmuext_op(mcs
.mc
, op
, 1, NULL
, DOMID_SELF
);
563 xen_mc_issue(PARAVIRT_LAZY_MMU
);
568 static void xen_flush_tlb_others(const cpumask_t
*cpus
, struct mm_struct
*mm
,
575 cpumask_t cpumask
= *cpus
;
576 struct multicall_space mcs
;
579 * A couple of (to be removed) sanity checks:
581 * - current CPU must not be in mask
582 * - mask must exist :)
584 BUG_ON(cpus_empty(cpumask
));
585 BUG_ON(cpu_isset(smp_processor_id(), cpumask
));
588 /* If a CPU which we ran on has gone down, OK. */
589 cpus_and(cpumask
, cpumask
, cpu_online_map
);
590 if (cpus_empty(cpumask
))
593 mcs
= xen_mc_entry(sizeof(*args
));
595 args
->mask
= cpumask
;
596 args
->op
.arg2
.vcpumask
= &args
->mask
;
598 if (va
== TLB_FLUSH_ALL
) {
599 args
->op
.cmd
= MMUEXT_TLB_FLUSH_MULTI
;
601 args
->op
.cmd
= MMUEXT_INVLPG_MULTI
;
602 args
->op
.arg1
.linear_addr
= va
;
605 MULTI_mmuext_op(mcs
.mc
, &args
->op
, 1, NULL
, DOMID_SELF
);
607 xen_mc_issue(PARAVIRT_LAZY_MMU
);
610 static void xen_write_cr2(unsigned long cr2
)
612 x86_read_percpu(xen_vcpu
)->arch
.cr2
= cr2
;
615 static unsigned long xen_read_cr2(void)
617 return x86_read_percpu(xen_vcpu
)->arch
.cr2
;
620 static unsigned long xen_read_cr2_direct(void)
622 return x86_read_percpu(xen_vcpu_info
.arch
.cr2
);
625 static void xen_write_cr4(unsigned long cr4
)
627 /* Just ignore cr4 changes; Xen doesn't allow us to do
631 static unsigned long xen_read_cr3(void)
633 return x86_read_percpu(xen_cr3
);
636 static void set_current_cr3(void *v
)
638 x86_write_percpu(xen_current_cr3
, (unsigned long)v
);
641 static void xen_write_cr3(unsigned long cr3
)
643 struct mmuext_op
*op
;
644 struct multicall_space mcs
;
645 unsigned long mfn
= pfn_to_mfn(PFN_DOWN(cr3
));
647 BUG_ON(preemptible());
649 mcs
= xen_mc_entry(sizeof(*op
)); /* disables interrupts */
651 /* Update while interrupts are disabled, so its atomic with
653 x86_write_percpu(xen_cr3
, cr3
);
656 op
->cmd
= MMUEXT_NEW_BASEPTR
;
659 MULTI_mmuext_op(mcs
.mc
, op
, 1, NULL
, DOMID_SELF
);
661 /* Update xen_update_cr3 once the batch has actually
663 xen_mc_callback(set_current_cr3
, (void *)cr3
);
665 xen_mc_issue(PARAVIRT_LAZY_CPU
); /* interrupts restored */
668 /* Early in boot, while setting up the initial pagetable, assume
669 everything is pinned. */
670 static __init
void xen_alloc_pte_init(struct mm_struct
*mm
, u32 pfn
)
672 #ifdef CONFIG_FLATMEM
673 BUG_ON(mem_map
); /* should only be used early */
675 make_lowmem_page_readonly(__va(PFN_PHYS(pfn
)));
678 /* Early release_pte assumes that all pts are pinned, since there's
679 only init_mm and anything attached to that is pinned. */
680 static void xen_release_pte_init(u32 pfn
)
682 make_lowmem_page_readwrite(__va(PFN_PHYS(pfn
)));
685 static void pin_pagetable_pfn(unsigned cmd
, unsigned long pfn
)
689 op
.arg1
.mfn
= pfn_to_mfn(pfn
);
690 if (HYPERVISOR_mmuext_op(&op
, 1, NULL
, DOMID_SELF
))
694 /* This needs to make sure the new pte page is pinned iff its being
695 attached to a pinned pagetable. */
696 static void xen_alloc_ptpage(struct mm_struct
*mm
, u32 pfn
, unsigned level
)
698 struct page
*page
= pfn_to_page(pfn
);
700 if (PagePinned(virt_to_page(mm
->pgd
))) {
703 if (!PageHighMem(page
)) {
704 make_lowmem_page_readonly(__va(PFN_PHYS(pfn
)));
706 pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE
, pfn
);
708 /* make sure there are no stray mappings of
714 static void xen_alloc_pte(struct mm_struct
*mm
, u32 pfn
)
716 xen_alloc_ptpage(mm
, pfn
, PT_PTE
);
719 static void xen_alloc_pmd(struct mm_struct
*mm
, u32 pfn
)
721 xen_alloc_ptpage(mm
, pfn
, PT_PMD
);
724 /* This should never happen until we're OK to use struct page */
725 static void xen_release_ptpage(u32 pfn
, unsigned level
)
727 struct page
*page
= pfn_to_page(pfn
);
729 if (PagePinned(page
)) {
730 if (!PageHighMem(page
)) {
732 pin_pagetable_pfn(MMUEXT_UNPIN_TABLE
, pfn
);
733 make_lowmem_page_readwrite(__va(PFN_PHYS(pfn
)));
735 ClearPagePinned(page
);
739 static void xen_release_pte(u32 pfn
)
741 xen_release_ptpage(pfn
, PT_PTE
);
744 static void xen_release_pmd(u32 pfn
)
746 xen_release_ptpage(pfn
, PT_PMD
);
749 #ifdef CONFIG_HIGHPTE
750 static void *xen_kmap_atomic_pte(struct page
*page
, enum km_type type
)
752 pgprot_t prot
= PAGE_KERNEL
;
754 if (PagePinned(page
))
755 prot
= PAGE_KERNEL_RO
;
757 if (0 && PageHighMem(page
))
758 printk("mapping highpte %lx type %d prot %s\n",
759 page_to_pfn(page
), type
,
760 (unsigned long)pgprot_val(prot
) & _PAGE_RW
? "WRITE" : "READ");
762 return kmap_atomic_prot(page
, type
, prot
);
766 static __init pte_t
mask_rw_pte(pte_t
*ptep
, pte_t pte
)
768 /* If there's an existing pte, then don't allow _PAGE_RW to be set */
769 if (pte_val_ma(*ptep
) & _PAGE_PRESENT
)
770 pte
= __pte_ma(((pte_val_ma(*ptep
) & _PAGE_RW
) | ~_PAGE_RW
) &
776 /* Init-time set_pte while constructing initial pagetables, which
777 doesn't allow RO pagetable pages to be remapped RW */
778 static __init
void xen_set_pte_init(pte_t
*ptep
, pte_t pte
)
780 pte
= mask_rw_pte(ptep
, pte
);
782 xen_set_pte(ptep
, pte
);
785 static __init
void xen_pagetable_setup_start(pgd_t
*base
)
787 pgd_t
*xen_pgd
= (pgd_t
*)xen_start_info
->pt_base
;
789 /* special set_pte for pagetable initialization */
790 pv_mmu_ops
.set_pte
= xen_set_pte_init
;
794 * copy top-level of Xen-supplied pagetable into place. For
795 * !PAE we can use this as-is, but for PAE it is a stand-in
796 * while we copy the pmd pages.
798 memcpy(base
, xen_pgd
, PTRS_PER_PGD
* sizeof(pgd_t
));
800 if (PTRS_PER_PMD
> 1) {
803 * For PAE, need to allocate new pmds, rather than
804 * share Xen's, since Xen doesn't like pmd's being
805 * shared between address spaces.
807 for (i
= 0; i
< PTRS_PER_PGD
; i
++) {
808 if (pgd_val_ma(xen_pgd
[i
]) & _PAGE_PRESENT
) {
809 pmd_t
*pmd
= (pmd_t
*)alloc_bootmem_low_pages(PAGE_SIZE
);
811 memcpy(pmd
, (void *)pgd_page_vaddr(xen_pgd
[i
]),
814 make_lowmem_page_readonly(pmd
);
816 set_pgd(&base
[i
], __pgd(1 + __pa(pmd
)));
822 /* make sure zero_page is mapped RO so we can use it in pagetables */
823 make_lowmem_page_readonly(empty_zero_page
);
824 make_lowmem_page_readonly(base
);
826 * Switch to new pagetable. This is done before
827 * pagetable_init has done anything so that the new pages
828 * added to the table can be prepared properly for Xen.
830 xen_write_cr3(__pa(base
));
832 /* Unpin initial Xen pagetable */
833 pin_pagetable_pfn(MMUEXT_UNPIN_TABLE
,
834 PFN_DOWN(__pa(xen_start_info
->pt_base
)));
837 static __init
void setup_shared_info(void)
839 if (!xen_feature(XENFEAT_auto_translated_physmap
)) {
840 unsigned long addr
= fix_to_virt(FIX_PARAVIRT_BOOTMAP
);
843 * Create a mapping for the shared info page.
844 * Should be set_fixmap(), but shared_info is a machine
845 * address with no corresponding pseudo-phys address.
848 PFN_DOWN(xen_start_info
->shared_info
),
851 HYPERVISOR_shared_info
= (struct shared_info
*)addr
;
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();
862 static __init
void xen_pagetable_setup_done(pgd_t
*base
)
864 /* This will work as long as patching hasn't happened yet
866 pv_mmu_ops
.alloc_pte
= xen_alloc_pte
;
867 pv_mmu_ops
.alloc_pmd
= xen_alloc_pmd
;
868 pv_mmu_ops
.release_pte
= xen_release_pte
;
869 pv_mmu_ops
.release_pmd
= xen_release_pmd
;
870 pv_mmu_ops
.set_pte
= xen_set_pte
;
874 /* Actually pin the pagetable down, but we can't set PG_pinned
875 yet because the page structures don't exist yet. */
879 #ifdef CONFIG_X86_PAE
880 level
= MMUEXT_PIN_L3_TABLE
;
882 level
= MMUEXT_PIN_L2_TABLE
;
885 pin_pagetable_pfn(level
, PFN_DOWN(__pa(base
)));
889 /* This is called once we have the cpu_possible_map */
890 void __init
xen_setup_vcpu_info_placement(void)
894 for_each_possible_cpu(cpu
)
897 /* xen_vcpu_setup managed to place the vcpu_info within the
898 percpu area for all cpus, so make use of it */
899 if (have_vcpu_info_placement
) {
900 printk(KERN_INFO
"Xen: using vcpu_info placement\n");
902 pv_irq_ops
.save_fl
= xen_save_fl_direct
;
903 pv_irq_ops
.restore_fl
= xen_restore_fl_direct
;
904 pv_irq_ops
.irq_disable
= xen_irq_disable_direct
;
905 pv_irq_ops
.irq_enable
= xen_irq_enable_direct
;
906 pv_mmu_ops
.read_cr2
= xen_read_cr2_direct
;
910 static unsigned xen_patch(u8 type
, u16 clobbers
, void *insnbuf
,
911 unsigned long addr
, unsigned len
)
913 char *start
, *end
, *reloc
;
916 start
= end
= reloc
= NULL
;
918 #define SITE(op, x) \
919 case PARAVIRT_PATCH(op.x): \
920 if (have_vcpu_info_placement) { \
921 start = (char *)xen_##x##_direct; \
922 end = xen_##x##_direct_end; \
923 reloc = xen_##x##_direct_reloc; \
928 SITE(pv_irq_ops
, irq_enable
);
929 SITE(pv_irq_ops
, irq_disable
);
930 SITE(pv_irq_ops
, save_fl
);
931 SITE(pv_irq_ops
, restore_fl
);
935 if (start
== NULL
|| (end
-start
) > len
)
938 ret
= paravirt_patch_insns(insnbuf
, len
, start
, end
);
940 /* Note: because reloc is assigned from something that
941 appears to be an array, gcc assumes it's non-null,
942 but doesn't know its relationship with start and
944 if (reloc
> start
&& reloc
< end
) {
945 int reloc_off
= reloc
- start
;
946 long *relocp
= (long *)(insnbuf
+ reloc_off
);
947 long delta
= start
- (char *)addr
;
955 ret
= paravirt_patch_default(type
, clobbers
, insnbuf
,
963 static const struct pv_info xen_info __initdata
= {
964 .paravirt_enabled
= 1,
965 .shared_kernel_pmd
= 0,
970 static const struct pv_init_ops xen_init_ops __initdata
= {
973 .banner
= xen_banner
,
974 .memory_setup
= xen_memory_setup
,
975 .arch_setup
= xen_arch_setup
,
976 .post_allocator_init
= xen_mark_init_mm_pinned
,
979 static const struct pv_time_ops xen_time_ops __initdata
= {
980 .time_init
= xen_time_init
,
982 .set_wallclock
= xen_set_wallclock
,
983 .get_wallclock
= xen_get_wallclock
,
984 .get_cpu_khz
= xen_cpu_khz
,
985 .sched_clock
= xen_sched_clock
,
988 static const struct pv_cpu_ops xen_cpu_ops __initdata
= {
991 .set_debugreg
= xen_set_debugreg
,
992 .get_debugreg
= xen_get_debugreg
,
996 .read_cr0
= native_read_cr0
,
997 .write_cr0
= native_write_cr0
,
999 .read_cr4
= native_read_cr4
,
1000 .read_cr4_safe
= native_read_cr4_safe
,
1001 .write_cr4
= xen_write_cr4
,
1003 .wbinvd
= native_wbinvd
,
1005 .read_msr
= native_read_msr_safe
,
1006 .write_msr
= native_write_msr_safe
,
1007 .read_tsc
= native_read_tsc
,
1008 .read_pmc
= native_read_pmc
,
1011 .irq_enable_syscall_ret
= xen_sysexit
,
1013 .load_tr_desc
= paravirt_nop
,
1014 .set_ldt
= xen_set_ldt
,
1015 .load_gdt
= xen_load_gdt
,
1016 .load_idt
= xen_load_idt
,
1017 .load_tls
= xen_load_tls
,
1019 .store_gdt
= native_store_gdt
,
1020 .store_idt
= native_store_idt
,
1021 .store_tr
= xen_store_tr
,
1023 .write_ldt_entry
= xen_write_ldt_entry
,
1024 .write_gdt_entry
= xen_write_gdt_entry
,
1025 .write_idt_entry
= xen_write_idt_entry
,
1026 .load_sp0
= xen_load_sp0
,
1028 .set_iopl_mask
= xen_set_iopl_mask
,
1029 .io_delay
= xen_io_delay
,
1032 .enter
= paravirt_enter_lazy_cpu
,
1033 .leave
= xen_leave_lazy
,
1037 static const struct pv_irq_ops xen_irq_ops __initdata
= {
1038 .init_IRQ
= xen_init_IRQ
,
1039 .save_fl
= xen_save_fl
,
1040 .restore_fl
= xen_restore_fl
,
1041 .irq_disable
= xen_irq_disable
,
1042 .irq_enable
= xen_irq_enable
,
1043 .safe_halt
= xen_safe_halt
,
1047 static const struct pv_apic_ops xen_apic_ops __initdata
= {
1048 #ifdef CONFIG_X86_LOCAL_APIC
1049 .apic_write
= xen_apic_write
,
1050 .apic_write_atomic
= xen_apic_write
,
1051 .apic_read
= xen_apic_read
,
1052 .setup_boot_clock
= paravirt_nop
,
1053 .setup_secondary_clock
= paravirt_nop
,
1054 .startup_ipi_hook
= paravirt_nop
,
1058 static const struct pv_mmu_ops xen_mmu_ops __initdata
= {
1059 .pagetable_setup_start
= xen_pagetable_setup_start
,
1060 .pagetable_setup_done
= xen_pagetable_setup_done
,
1062 .read_cr2
= xen_read_cr2
,
1063 .write_cr2
= xen_write_cr2
,
1065 .read_cr3
= xen_read_cr3
,
1066 .write_cr3
= xen_write_cr3
,
1068 .flush_tlb_user
= xen_flush_tlb
,
1069 .flush_tlb_kernel
= xen_flush_tlb
,
1070 .flush_tlb_single
= xen_flush_tlb_single
,
1071 .flush_tlb_others
= xen_flush_tlb_others
,
1073 .pte_update
= paravirt_nop
,
1074 .pte_update_defer
= paravirt_nop
,
1076 .alloc_pte
= xen_alloc_pte_init
,
1077 .release_pte
= xen_release_pte_init
,
1078 .alloc_pmd
= xen_alloc_pte_init
,
1079 .alloc_pmd_clone
= paravirt_nop
,
1080 .release_pmd
= xen_release_pte_init
,
1082 #ifdef CONFIG_HIGHPTE
1083 .kmap_atomic_pte
= xen_kmap_atomic_pte
,
1086 .set_pte
= NULL
, /* see xen_pagetable_setup_* */
1087 .set_pte_at
= xen_set_pte_at
,
1088 .set_pmd
= xen_set_pmd
,
1090 .pte_val
= xen_pte_val
,
1091 .pgd_val
= xen_pgd_val
,
1093 .make_pte
= xen_make_pte
,
1094 .make_pgd
= xen_make_pgd
,
1096 #ifdef CONFIG_X86_PAE
1097 .set_pte_atomic
= xen_set_pte_atomic
,
1098 .set_pte_present
= xen_set_pte_at
,
1099 .set_pud
= xen_set_pud
,
1100 .pte_clear
= xen_pte_clear
,
1101 .pmd_clear
= xen_pmd_clear
,
1103 .make_pmd
= xen_make_pmd
,
1104 .pmd_val
= xen_pmd_val
,
1107 .activate_mm
= xen_activate_mm
,
1108 .dup_mmap
= xen_dup_mmap
,
1109 .exit_mmap
= xen_exit_mmap
,
1112 .enter
= paravirt_enter_lazy_mmu
,
1113 .leave
= xen_leave_lazy
,
1118 static const struct smp_ops xen_smp_ops __initdata
= {
1119 .smp_prepare_boot_cpu
= xen_smp_prepare_boot_cpu
,
1120 .smp_prepare_cpus
= xen_smp_prepare_cpus
,
1121 .cpu_up
= xen_cpu_up
,
1122 .smp_cpus_done
= xen_smp_cpus_done
,
1124 .smp_send_stop
= xen_smp_send_stop
,
1125 .smp_send_reschedule
= xen_smp_send_reschedule
,
1126 .smp_call_function_mask
= xen_smp_call_function_mask
,
1128 #endif /* CONFIG_SMP */
1130 static void xen_reboot(int reason
)
1136 if (HYPERVISOR_sched_op(SCHEDOP_shutdown
, reason
))
1140 static void xen_restart(char *msg
)
1142 xen_reboot(SHUTDOWN_reboot
);
1145 static void xen_emergency_restart(void)
1147 xen_reboot(SHUTDOWN_reboot
);
1150 static void xen_machine_halt(void)
1152 xen_reboot(SHUTDOWN_poweroff
);
1155 static void xen_crash_shutdown(struct pt_regs
*regs
)
1157 xen_reboot(SHUTDOWN_crash
);
1160 static const struct machine_ops __initdata xen_machine_ops
= {
1161 .restart
= xen_restart
,
1162 .halt
= xen_machine_halt
,
1163 .power_off
= xen_machine_halt
,
1164 .shutdown
= xen_machine_halt
,
1165 .crash_shutdown
= xen_crash_shutdown
,
1166 .emergency_restart
= xen_emergency_restart
,
1170 static void __init
xen_reserve_top(void)
1172 unsigned long top
= HYPERVISOR_VIRT_START
;
1173 struct xen_platform_parameters pp
;
1175 if (HYPERVISOR_xen_version(XENVER_platform_parameters
, &pp
) == 0)
1176 top
= pp
.virt_start
;
1178 reserve_top_address(-top
+ 2 * PAGE_SIZE
);
1181 /* First C function to be called on Xen boot */
1182 asmlinkage
void __init
xen_start_kernel(void)
1186 if (!xen_start_info
)
1189 BUG_ON(memcmp(xen_start_info
->magic
, "xen-3", 5) != 0);
1191 /* Install Xen paravirt ops */
1193 pv_init_ops
= xen_init_ops
;
1194 pv_time_ops
= xen_time_ops
;
1195 pv_cpu_ops
= xen_cpu_ops
;
1196 pv_irq_ops
= xen_irq_ops
;
1197 pv_apic_ops
= xen_apic_ops
;
1198 pv_mmu_ops
= xen_mmu_ops
;
1200 machine_ops
= xen_machine_ops
;
1203 smp_ops
= xen_smp_ops
;
1206 xen_setup_features();
1209 if (!xen_feature(XENFEAT_auto_translated_physmap
))
1210 phys_to_machine_mapping
= (unsigned long *)xen_start_info
->mfn_list
;
1212 pgd
= (pgd_t
*)xen_start_info
->pt_base
;
1214 init_pg_tables_end
= __pa(pgd
) + xen_start_info
->nr_pt_frames
*PAGE_SIZE
;
1216 init_mm
.pgd
= pgd
; /* use the Xen pagetables to start */
1218 /* keep using Xen gdt for now; no urgent need to change it */
1220 x86_write_percpu(xen_cr3
, __pa(pgd
));
1221 x86_write_percpu(xen_current_cr3
, __pa(pgd
));
1223 /* Don't do the full vcpu_info placement stuff until we have a
1224 possible map and a non-dummy shared_info. */
1225 per_cpu(xen_vcpu
, 0) = &HYPERVISOR_shared_info
->vcpu_info
[0];
1227 pv_info
.kernel_rpl
= 1;
1228 if (xen_feature(XENFEAT_supervisor_mode_kernel
))
1229 pv_info
.kernel_rpl
= 0;
1231 /* set the limit of our address space */
1234 /* set up basic CPUID stuff */
1235 cpu_detect(&new_cpu_data
);
1236 new_cpu_data
.hard_math
= 1;
1237 new_cpu_data
.x86_capability
[0] = cpuid_edx(1);
1239 /* Poke various useful things into boot_params */
1240 boot_params
.hdr
.type_of_loader
= (9 << 4) | 0;
1241 boot_params
.hdr
.ramdisk_image
= xen_start_info
->mod_start
1242 ? __pa(xen_start_info
->mod_start
) : 0;
1243 boot_params
.hdr
.ramdisk_size
= xen_start_info
->mod_len
;
1245 if (!is_initial_xendomain())
1246 add_preferred_console("hvc", 0, NULL
);
1248 /* Start the world */