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/percpu.h>
19 #include <linux/delay.h>
20 #include <linux/start_kernel.h>
21 #include <linux/sched.h>
22 #include <linux/bootmem.h>
23 #include <linux/module.h>
25 #include <linux/page-flags.h>
26 #include <linux/highmem.h>
28 #include <xen/interface/xen.h>
29 #include <xen/interface/physdev.h>
30 #include <xen/interface/vcpu.h>
31 #include <xen/features.h>
34 #include <asm/paravirt.h>
36 #include <asm/xen/hypercall.h>
37 #include <asm/xen/hypervisor.h>
38 #include <asm/fixmap.h>
39 #include <asm/processor.h>
40 #include <asm/setup.h>
42 #include <asm/pgtable.h>
46 #include "multicalls.h"
48 EXPORT_SYMBOL_GPL(hypercall_page
);
50 DEFINE_PER_CPU(enum paravirt_lazy_mode
, xen_lazy_mode
);
52 DEFINE_PER_CPU(struct vcpu_info
*, xen_vcpu
);
53 DEFINE_PER_CPU(struct vcpu_info
, xen_vcpu_info
);
54 DEFINE_PER_CPU(unsigned long, xen_cr3
);
56 struct start_info
*xen_start_info
;
57 EXPORT_SYMBOL_GPL(xen_start_info
);
59 static void xen_vcpu_setup(int cpu
)
61 per_cpu(xen_vcpu
, cpu
) = &HYPERVISOR_shared_info
->vcpu_info
[cpu
];
64 static void __init
xen_banner(void)
66 printk(KERN_INFO
"Booting paravirtualized kernel on %s\n",
68 printk(KERN_INFO
"Hypervisor signature: %s\n", xen_start_info
->magic
);
71 static void xen_cpuid(unsigned int *eax
, unsigned int *ebx
,
72 unsigned int *ecx
, unsigned int *edx
)
74 unsigned maskedx
= ~0;
77 * Mask out inconvenient features, to try and disable as many
78 * unsupported kernel subsystems as possible.
81 maskedx
= ~((1 << X86_FEATURE_APIC
) | /* disable APIC */
82 (1 << X86_FEATURE_ACPI
) | /* disable ACPI */
83 (1 << X86_FEATURE_ACC
)); /* thermal monitoring */
85 asm(XEN_EMULATE_PREFIX
"cpuid"
90 : "0" (*eax
), "2" (*ecx
));
94 static void xen_set_debugreg(int reg
, unsigned long val
)
96 HYPERVISOR_set_debugreg(reg
, val
);
99 static unsigned long xen_get_debugreg(int reg
)
101 return HYPERVISOR_get_debugreg(reg
);
104 static unsigned long xen_save_fl(void)
106 struct vcpu_info
*vcpu
;
110 vcpu
= x86_read_percpu(xen_vcpu
);
111 /* flag has opposite sense of mask */
112 flags
= !vcpu
->evtchn_upcall_mask
;
115 /* convert to IF type flag
119 return (-flags
) & X86_EFLAGS_IF
;
122 static void xen_restore_fl(unsigned long flags
)
124 struct vcpu_info
*vcpu
;
128 /* convert from IF type flag */
129 flags
= !(flags
& X86_EFLAGS_IF
);
130 vcpu
= x86_read_percpu(xen_vcpu
);
131 vcpu
->evtchn_upcall_mask
= flags
;
134 /* Unmask then check (avoid races). We're only protecting
135 against updates by this CPU, so there's no need for
136 anything stronger. */
139 if (unlikely(vcpu
->evtchn_upcall_pending
))
140 force_evtchn_callback();
143 preempt_enable_no_resched();
146 static void xen_irq_disable(void)
148 struct vcpu_info
*vcpu
;
150 vcpu
= x86_read_percpu(xen_vcpu
);
151 vcpu
->evtchn_upcall_mask
= 1;
152 preempt_enable_no_resched();
155 static void xen_irq_enable(void)
157 struct vcpu_info
*vcpu
;
160 vcpu
= x86_read_percpu(xen_vcpu
);
161 vcpu
->evtchn_upcall_mask
= 0;
163 /* Unmask then check (avoid races). We're only protecting
164 against updates by this CPU, so there's no need for
165 anything stronger. */
168 if (unlikely(vcpu
->evtchn_upcall_pending
))
169 force_evtchn_callback();
173 static void xen_safe_halt(void)
175 /* Blocking includes an implicit local_irq_enable(). */
176 if (HYPERVISOR_sched_op(SCHEDOP_block
, 0) != 0)
180 static void xen_halt(void)
183 HYPERVISOR_vcpu_op(VCPUOP_down
, smp_processor_id(), NULL
);
188 static void xen_set_lazy_mode(enum paravirt_lazy_mode mode
)
191 case PARAVIRT_LAZY_NONE
:
192 BUG_ON(x86_read_percpu(xen_lazy_mode
) == PARAVIRT_LAZY_NONE
);
195 case PARAVIRT_LAZY_MMU
:
196 case PARAVIRT_LAZY_CPU
:
197 BUG_ON(x86_read_percpu(xen_lazy_mode
) != PARAVIRT_LAZY_NONE
);
200 case PARAVIRT_LAZY_FLUSH
:
201 /* flush if necessary, but don't change state */
202 if (x86_read_percpu(xen_lazy_mode
) != PARAVIRT_LAZY_NONE
)
208 x86_write_percpu(xen_lazy_mode
, mode
);
211 static unsigned long xen_store_tr(void)
216 static void xen_set_ldt(const void *addr
, unsigned entries
)
218 unsigned long linear_addr
= (unsigned long)addr
;
219 struct mmuext_op
*op
;
220 struct multicall_space mcs
= xen_mc_entry(sizeof(*op
));
223 op
->cmd
= MMUEXT_SET_LDT
;
225 /* ldt my be vmalloced, use arbitrary_virt_to_machine */
227 maddr
= arbitrary_virt_to_machine((unsigned long)addr
);
228 linear_addr
= (unsigned long)maddr
.maddr
;
230 op
->arg1
.linear_addr
= linear_addr
;
231 op
->arg2
.nr_ents
= entries
;
233 MULTI_mmuext_op(mcs
.mc
, op
, 1, NULL
, DOMID_SELF
);
235 xen_mc_issue(PARAVIRT_LAZY_CPU
);
238 static void xen_load_gdt(const struct Xgt_desc_struct
*dtr
)
240 unsigned long *frames
;
241 unsigned long va
= dtr
->address
;
242 unsigned int size
= dtr
->size
+ 1;
243 unsigned pages
= (size
+ PAGE_SIZE
- 1) / PAGE_SIZE
;
245 struct multicall_space mcs
;
247 /* A GDT can be up to 64k in size, which corresponds to 8192
248 8-byte entries, or 16 4k pages.. */
250 BUG_ON(size
> 65536);
251 BUG_ON(va
& ~PAGE_MASK
);
253 mcs
= xen_mc_entry(sizeof(*frames
) * pages
);
256 for (f
= 0; va
< dtr
->address
+ size
; va
+= PAGE_SIZE
, f
++) {
257 frames
[f
] = virt_to_mfn(va
);
258 make_lowmem_page_readonly((void *)va
);
261 MULTI_set_gdt(mcs
.mc
, frames
, size
/ sizeof(struct desc_struct
));
263 xen_mc_issue(PARAVIRT_LAZY_CPU
);
266 static void load_TLS_descriptor(struct thread_struct
*t
,
267 unsigned int cpu
, unsigned int i
)
269 struct desc_struct
*gdt
= get_cpu_gdt_table(cpu
);
270 xmaddr_t maddr
= virt_to_machine(&gdt
[GDT_ENTRY_TLS_MIN
+i
]);
271 struct multicall_space mc
= __xen_mc_entry(0);
273 MULTI_update_descriptor(mc
.mc
, maddr
.maddr
, t
->tls_array
[i
]);
276 static void xen_load_tls(struct thread_struct
*t
, unsigned int cpu
)
280 load_TLS_descriptor(t
, cpu
, 0);
281 load_TLS_descriptor(t
, cpu
, 1);
282 load_TLS_descriptor(t
, cpu
, 2);
284 xen_mc_issue(PARAVIRT_LAZY_CPU
);
287 static void xen_write_ldt_entry(struct desc_struct
*dt
, int entrynum
,
290 unsigned long lp
= (unsigned long)&dt
[entrynum
];
291 xmaddr_t mach_lp
= virt_to_machine(lp
);
292 u64 entry
= (u64
)high
<< 32 | low
;
295 if (HYPERVISOR_update_descriptor(mach_lp
.maddr
, entry
))
299 static int cvt_gate_to_trap(int vector
, u32 low
, u32 high
,
300 struct trap_info
*info
)
304 type
= (high
>> 8) & 0x1f;
305 dpl
= (high
>> 13) & 3;
307 if (type
!= 0xf && type
!= 0xe)
310 info
->vector
= vector
;
311 info
->address
= (high
& 0xffff0000) | (low
& 0x0000ffff);
312 info
->cs
= low
>> 16;
314 /* interrupt gates clear IF */
321 /* Locations of each CPU's IDT */
322 static DEFINE_PER_CPU(struct Xgt_desc_struct
, idt_desc
);
324 /* Set an IDT entry. If the entry is part of the current IDT, then
326 static void xen_write_idt_entry(struct desc_struct
*dt
, int entrynum
,
330 int cpu
= smp_processor_id();
331 unsigned long p
= (unsigned long)&dt
[entrynum
];
332 unsigned long start
= per_cpu(idt_desc
, cpu
).address
;
333 unsigned long end
= start
+ per_cpu(idt_desc
, cpu
).size
+ 1;
337 write_dt_entry(dt
, entrynum
, low
, high
);
339 if (p
>= start
&& (p
+ 8) <= end
) {
340 struct trap_info info
[2];
344 if (cvt_gate_to_trap(entrynum
, low
, high
, &info
[0]))
345 if (HYPERVISOR_set_trap_table(info
))
350 /* Load a new IDT into Xen. In principle this can be per-CPU, so we
351 hold a spinlock to protect the static traps[] array (static because
352 it avoids allocation, and saves stack space). */
353 static void xen_load_idt(const struct Xgt_desc_struct
*desc
)
355 static DEFINE_SPINLOCK(lock
);
356 static struct trap_info traps
[257];
358 int cpu
= smp_processor_id();
359 unsigned in
, out
, count
;
361 per_cpu(idt_desc
, cpu
) = *desc
;
363 count
= (desc
->size
+1) / 8;
367 for (in
= out
= 0; in
< count
; in
++) {
368 const u32
*entry
= (u32
*)(desc
->address
+ in
* 8);
370 if (cvt_gate_to_trap(in
, entry
[0], entry
[1], &traps
[out
]))
373 traps
[out
].address
= 0;
376 if (HYPERVISOR_set_trap_table(traps
))
382 /* Write a GDT descriptor entry. Ignore LDT descriptors, since
383 they're handled differently. */
384 static void xen_write_gdt_entry(struct desc_struct
*dt
, int entry
,
387 switch ((high
>> 8) & 0xff) {
394 xmaddr_t maddr
= virt_to_machine(&dt
[entry
]);
395 u64 desc
= (u64
)high
<< 32 | low
;
398 if (HYPERVISOR_update_descriptor(maddr
.maddr
, desc
))
405 static void xen_load_esp0(struct tss_struct
*tss
,
406 struct thread_struct
*thread
)
408 struct multicall_space mcs
= xen_mc_entry(0);
409 MULTI_stack_switch(mcs
.mc
, __KERNEL_DS
, thread
->esp0
);
410 xen_mc_issue(PARAVIRT_LAZY_CPU
);
413 static void xen_set_iopl_mask(unsigned mask
)
415 struct physdev_set_iopl set_iopl
;
417 /* Force the change at ring 0. */
418 set_iopl
.iopl
= (mask
== 0) ? 1 : (mask
>> 12) & 3;
419 HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl
, &set_iopl
);
422 static void xen_io_delay(void)
426 #ifdef CONFIG_X86_LOCAL_APIC
427 static unsigned long xen_apic_read(unsigned long reg
)
433 static void xen_flush_tlb(void)
437 op
.cmd
= MMUEXT_TLB_FLUSH_LOCAL
;
438 if (HYPERVISOR_mmuext_op(&op
, 1, NULL
, DOMID_SELF
))
442 static void xen_flush_tlb_single(unsigned long addr
)
446 op
.cmd
= MMUEXT_INVLPG_LOCAL
;
447 op
.arg1
.linear_addr
= addr
& PAGE_MASK
;
448 if (HYPERVISOR_mmuext_op(&op
, 1, NULL
, DOMID_SELF
))
452 static unsigned long xen_read_cr2(void)
454 return x86_read_percpu(xen_vcpu
)->arch
.cr2
;
457 static void xen_write_cr4(unsigned long cr4
)
459 /* never allow TSC to be disabled */
460 native_write_cr4(cr4
& ~X86_CR4_TSD
);
464 * Page-directory addresses above 4GB do not fit into architectural %cr3.
465 * When accessing %cr3, or equivalent field in vcpu_guest_context, guests
466 * must use the following accessor macros to pack/unpack valid MFNs.
468 * Note that Xen is using the fact that the pagetable base is always
469 * page-aligned, and putting the 12 MSB of the address into the 12 LSB
472 #define xen_pfn_to_cr3(pfn) (((unsigned)(pfn) << 12) | ((unsigned)(pfn) >> 20))
473 #define xen_cr3_to_pfn(cr3) (((unsigned)(cr3) >> 12) | ((unsigned)(cr3) << 20))
475 static unsigned long xen_read_cr3(void)
477 return x86_read_percpu(xen_cr3
);
480 static void xen_write_cr3(unsigned long cr3
)
482 if (cr3
== x86_read_percpu(xen_cr3
)) {
483 /* just a simple tlb flush */
488 x86_write_percpu(xen_cr3
, cr3
);
492 struct mmuext_op
*op
;
493 struct multicall_space mcs
= xen_mc_entry(sizeof(*op
));
494 unsigned long mfn
= pfn_to_mfn(PFN_DOWN(cr3
));
497 op
->cmd
= MMUEXT_NEW_BASEPTR
;
500 MULTI_mmuext_op(mcs
.mc
, op
, 1, NULL
, DOMID_SELF
);
502 xen_mc_issue(PARAVIRT_LAZY_CPU
);
506 /* Early in boot, while setting up the initial pagetable, assume
507 everything is pinned. */
508 static void xen_alloc_pt_init(struct mm_struct
*mm
, u32 pfn
)
510 BUG_ON(mem_map
); /* should only be used early */
511 make_lowmem_page_readonly(__va(PFN_PHYS(pfn
)));
514 /* This needs to make sure the new pte page is pinned iff its being
515 attached to a pinned pagetable. */
516 static void xen_alloc_pt(struct mm_struct
*mm
, u32 pfn
)
518 struct page
*page
= pfn_to_page(pfn
);
520 if (PagePinned(virt_to_page(mm
->pgd
))) {
523 if (!PageHighMem(page
))
524 make_lowmem_page_readonly(__va(PFN_PHYS(pfn
)));
526 /* make sure there are no stray mappings of
532 /* This should never happen until we're OK to use struct page */
533 static void xen_release_pt(u32 pfn
)
535 struct page
*page
= pfn_to_page(pfn
);
537 if (PagePinned(page
)) {
538 if (!PageHighMem(page
))
539 make_lowmem_page_readwrite(__va(PFN_PHYS(pfn
)));
543 #ifdef CONFIG_HIGHPTE
544 static void *xen_kmap_atomic_pte(struct page
*page
, enum km_type type
)
546 pgprot_t prot
= PAGE_KERNEL
;
548 if (PagePinned(page
))
549 prot
= PAGE_KERNEL_RO
;
551 if (0 && PageHighMem(page
))
552 printk("mapping highpte %lx type %d prot %s\n",
553 page_to_pfn(page
), type
,
554 (unsigned long)pgprot_val(prot
) & _PAGE_RW
? "WRITE" : "READ");
556 return kmap_atomic_prot(page
, type
, prot
);
560 static __init
void xen_pagetable_setup_start(pgd_t
*base
)
562 pgd_t
*xen_pgd
= (pgd_t
*)xen_start_info
->pt_base
;
566 * copy top-level of Xen-supplied pagetable into place. For
567 * !PAE we can use this as-is, but for PAE it is a stand-in
568 * while we copy the pmd pages.
570 memcpy(base
, xen_pgd
, PTRS_PER_PGD
* sizeof(pgd_t
));
572 if (PTRS_PER_PMD
> 1) {
575 * For PAE, need to allocate new pmds, rather than
576 * share Xen's, since Xen doesn't like pmd's being
577 * shared between address spaces.
579 for (i
= 0; i
< PTRS_PER_PGD
; i
++) {
580 if (pgd_val_ma(xen_pgd
[i
]) & _PAGE_PRESENT
) {
581 pmd_t
*pmd
= (pmd_t
*)alloc_bootmem_low_pages(PAGE_SIZE
);
583 memcpy(pmd
, (void *)pgd_page_vaddr(xen_pgd
[i
]),
586 make_lowmem_page_readonly(pmd
);
588 set_pgd(&base
[i
], __pgd(1 + __pa(pmd
)));
594 /* make sure zero_page is mapped RO so we can use it in pagetables */
595 make_lowmem_page_readonly(empty_zero_page
);
596 make_lowmem_page_readonly(base
);
598 * Switch to new pagetable. This is done before
599 * pagetable_init has done anything so that the new pages
600 * added to the table can be prepared properly for Xen.
602 xen_write_cr3(__pa(base
));
605 static __init
void xen_pagetable_setup_done(pgd_t
*base
)
607 /* This will work as long as patching hasn't happened yet
609 paravirt_ops
.alloc_pt
= xen_alloc_pt
;
611 if (!xen_feature(XENFEAT_auto_translated_physmap
)) {
613 * Create a mapping for the shared info page.
614 * Should be set_fixmap(), but shared_info is a machine
615 * address with no corresponding pseudo-phys address.
617 set_pte_mfn(fix_to_virt(FIX_PARAVIRT_BOOTMAP
),
618 PFN_DOWN(xen_start_info
->shared_info
),
621 HYPERVISOR_shared_info
=
622 (struct shared_info
*)fix_to_virt(FIX_PARAVIRT_BOOTMAP
);
625 HYPERVISOR_shared_info
=
626 (struct shared_info
*)__va(xen_start_info
->shared_info
);
628 /* Actually pin the pagetable down, but we can't set PG_pinned
629 yet because the page structures don't exist yet. */
632 #ifdef CONFIG_X86_PAE
633 op
.cmd
= MMUEXT_PIN_L3_TABLE
;
635 op
.cmd
= MMUEXT_PIN_L3_TABLE
;
637 op
.arg1
.mfn
= pfn_to_mfn(PFN_DOWN(__pa(base
)));
638 if (HYPERVISOR_mmuext_op(&op
, 1, NULL
, DOMID_SELF
))
642 xen_vcpu_setup(smp_processor_id());
645 static const struct paravirt_ops xen_paravirt_ops __initdata
= {
646 .paravirt_enabled
= 1,
647 .shared_kernel_pmd
= 0,
650 .banner
= xen_banner
,
652 .patch
= paravirt_patch_default
,
654 .memory_setup
= xen_memory_setup
,
655 .arch_setup
= xen_arch_setup
,
656 .init_IRQ
= xen_init_IRQ
,
657 .post_allocator_init
= xen_mark_init_mm_pinned
,
659 .time_init
= xen_time_init
,
660 .set_wallclock
= xen_set_wallclock
,
661 .get_wallclock
= xen_get_wallclock
,
662 .get_cpu_khz
= xen_cpu_khz
,
663 .sched_clock
= xen_clocksource_read
,
667 .set_debugreg
= xen_set_debugreg
,
668 .get_debugreg
= xen_get_debugreg
,
672 .read_cr0
= native_read_cr0
,
673 .write_cr0
= native_write_cr0
,
675 .read_cr2
= xen_read_cr2
,
676 .write_cr2
= native_write_cr2
,
678 .read_cr3
= xen_read_cr3
,
679 .write_cr3
= xen_write_cr3
,
681 .read_cr4
= native_read_cr4
,
682 .read_cr4_safe
= native_read_cr4_safe
,
683 .write_cr4
= xen_write_cr4
,
685 .save_fl
= xen_save_fl
,
686 .restore_fl
= xen_restore_fl
,
687 .irq_disable
= xen_irq_disable
,
688 .irq_enable
= xen_irq_enable
,
689 .safe_halt
= xen_safe_halt
,
691 .wbinvd
= native_wbinvd
,
693 .read_msr
= native_read_msr_safe
,
694 .write_msr
= native_write_msr_safe
,
695 .read_tsc
= native_read_tsc
,
696 .read_pmc
= native_read_pmc
,
698 .iret
= (void *)&hypercall_page
[__HYPERVISOR_iret
],
699 .irq_enable_sysexit
= NULL
, /* never called */
701 .load_tr_desc
= paravirt_nop
,
702 .set_ldt
= xen_set_ldt
,
703 .load_gdt
= xen_load_gdt
,
704 .load_idt
= xen_load_idt
,
705 .load_tls
= xen_load_tls
,
707 .store_gdt
= native_store_gdt
,
708 .store_idt
= native_store_idt
,
709 .store_tr
= xen_store_tr
,
711 .write_ldt_entry
= xen_write_ldt_entry
,
712 .write_gdt_entry
= xen_write_gdt_entry
,
713 .write_idt_entry
= xen_write_idt_entry
,
714 .load_esp0
= xen_load_esp0
,
716 .set_iopl_mask
= xen_set_iopl_mask
,
717 .io_delay
= xen_io_delay
,
719 #ifdef CONFIG_X86_LOCAL_APIC
720 .apic_write
= paravirt_nop
,
721 .apic_write_atomic
= paravirt_nop
,
722 .apic_read
= xen_apic_read
,
723 .setup_boot_clock
= paravirt_nop
,
724 .setup_secondary_clock
= paravirt_nop
,
725 .startup_ipi_hook
= paravirt_nop
,
728 .flush_tlb_user
= xen_flush_tlb
,
729 .flush_tlb_kernel
= xen_flush_tlb
,
730 .flush_tlb_single
= xen_flush_tlb_single
,
732 .pte_update
= paravirt_nop
,
733 .pte_update_defer
= paravirt_nop
,
735 .pagetable_setup_start
= xen_pagetable_setup_start
,
736 .pagetable_setup_done
= xen_pagetable_setup_done
,
738 .alloc_pt
= xen_alloc_pt_init
,
739 .release_pt
= xen_release_pt
,
740 .alloc_pd
= paravirt_nop
,
741 .alloc_pd_clone
= paravirt_nop
,
742 .release_pd
= paravirt_nop
,
744 #ifdef CONFIG_HIGHPTE
745 .kmap_atomic_pte
= xen_kmap_atomic_pte
,
748 .set_pte
= xen_set_pte
,
749 .set_pte_at
= xen_set_pte_at
,
750 .set_pmd
= xen_set_pmd
,
752 .pte_val
= xen_pte_val
,
753 .pgd_val
= xen_pgd_val
,
755 .make_pte
= xen_make_pte
,
756 .make_pgd
= xen_make_pgd
,
758 #ifdef CONFIG_X86_PAE
759 .set_pte_atomic
= xen_set_pte_atomic
,
760 .set_pte_present
= xen_set_pte_at
,
761 .set_pud
= xen_set_pud
,
762 .pte_clear
= xen_pte_clear
,
763 .pmd_clear
= xen_pmd_clear
,
765 .make_pmd
= xen_make_pmd
,
766 .pmd_val
= xen_pmd_val
,
769 .activate_mm
= xen_activate_mm
,
770 .dup_mmap
= xen_dup_mmap
,
771 .exit_mmap
= xen_exit_mmap
,
773 .set_lazy_mode
= xen_set_lazy_mode
,
776 /* First C function to be called on Xen boot */
777 asmlinkage
void __init
xen_start_kernel(void)
784 BUG_ON(memcmp(xen_start_info
->magic
, "xen-3.0", 7) != 0);
786 /* Install Xen paravirt ops */
787 paravirt_ops
= xen_paravirt_ops
;
789 xen_setup_features();
792 if (!xen_feature(XENFEAT_auto_translated_physmap
))
793 phys_to_machine_mapping
= (unsigned long *)xen_start_info
->mfn_list
;
795 pgd
= (pgd_t
*)xen_start_info
->pt_base
;
797 init_pg_tables_end
= __pa(pgd
) + xen_start_info
->nr_pt_frames
*PAGE_SIZE
;
799 init_mm
.pgd
= pgd
; /* use the Xen pagetables to start */
801 /* keep using Xen gdt for now; no urgent need to change it */
803 x86_write_percpu(xen_cr3
, __pa(pgd
));
806 paravirt_ops
.kernel_rpl
= 1;
807 if (xen_feature(XENFEAT_supervisor_mode_kernel
))
808 paravirt_ops
.kernel_rpl
= 0;
810 /* set the limit of our address space */
811 reserve_top_address(-HYPERVISOR_VIRT_START
+ 2 * PAGE_SIZE
);
813 /* set up basic CPUID stuff */
814 cpu_detect(&new_cpu_data
);
815 new_cpu_data
.hard_math
= 1;
816 new_cpu_data
.x86_capability
[0] = cpuid_edx(1);
818 /* Poke various useful things into boot_params */
819 LOADER_TYPE
= (9 << 4) | 0;
820 INITRD_START
= xen_start_info
->mod_start
? __pa(xen_start_info
->mod_start
) : 0;
821 INITRD_SIZE
= xen_start_info
->mod_len
;
823 /* Start the world */