linux/arch/i386/xen/enlighten.c
Jeremy Fitzhardinge 9a4029fd34 xen: ignore RW mapping of RO pages in pagetable_init
When setting up the initial pagetable, which includes mappings of all
low physical memory, ignore a mapping which tries to set the RW bit on
an RO pte.  An RO pte indicates a page which is part of the current
pagetable, and so it cannot be allowed to become RW.

Once xen_pagetable_setup_done is called, set_pte reverts to its normal
behaviour.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Cc: ebiederm@xmission.com (Eric W. Biederman)
2007-07-18 08:47:43 -07:00

849 lines
20 KiB
C

/*
* Core of Xen paravirt_ops implementation.
*
* This file contains the xen_paravirt_ops structure itself, and the
* implementations for:
* - privileged instructions
* - interrupt flags
* - segment operations
* - booting and setup
*
* Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/preempt.h>
#include <linux/percpu.h>
#include <linux/delay.h>
#include <linux/start_kernel.h>
#include <linux/sched.h>
#include <linux/bootmem.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/page-flags.h>
#include <linux/highmem.h>
#include <xen/interface/xen.h>
#include <xen/interface/physdev.h>
#include <xen/interface/vcpu.h>
#include <xen/features.h>
#include <xen/page.h>
#include <asm/paravirt.h>
#include <asm/page.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>
#include <asm/fixmap.h>
#include <asm/processor.h>
#include <asm/setup.h>
#include <asm/desc.h>
#include <asm/pgtable.h>
#include "xen-ops.h"
#include "mmu.h"
#include "multicalls.h"
EXPORT_SYMBOL_GPL(hypercall_page);
DEFINE_PER_CPU(enum paravirt_lazy_mode, xen_lazy_mode);
DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
DEFINE_PER_CPU(unsigned long, xen_cr3);
struct start_info *xen_start_info;
EXPORT_SYMBOL_GPL(xen_start_info);
static void xen_vcpu_setup(int cpu)
{
per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
}
static void __init xen_banner(void)
{
printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
paravirt_ops.name);
printk(KERN_INFO "Hypervisor signature: %s\n", xen_start_info->magic);
}
static void xen_cpuid(unsigned int *eax, unsigned int *ebx,
unsigned int *ecx, unsigned int *edx)
{
unsigned maskedx = ~0;
/*
* Mask out inconvenient features, to try and disable as many
* unsupported kernel subsystems as possible.
*/
if (*eax == 1)
maskedx = ~((1 << X86_FEATURE_APIC) | /* disable APIC */
(1 << X86_FEATURE_ACPI) | /* disable ACPI */
(1 << X86_FEATURE_ACC)); /* thermal monitoring */
asm(XEN_EMULATE_PREFIX "cpuid"
: "=a" (*eax),
"=b" (*ebx),
"=c" (*ecx),
"=d" (*edx)
: "0" (*eax), "2" (*ecx));
*edx &= maskedx;
}
static void xen_set_debugreg(int reg, unsigned long val)
{
HYPERVISOR_set_debugreg(reg, val);
}
static unsigned long xen_get_debugreg(int reg)
{
return HYPERVISOR_get_debugreg(reg);
}
static unsigned long xen_save_fl(void)
{
struct vcpu_info *vcpu;
unsigned long flags;
preempt_disable();
vcpu = x86_read_percpu(xen_vcpu);
/* flag has opposite sense of mask */
flags = !vcpu->evtchn_upcall_mask;
preempt_enable();
/* convert to IF type flag
-0 -> 0x00000000
-1 -> 0xffffffff
*/
return (-flags) & X86_EFLAGS_IF;
}
static void xen_restore_fl(unsigned long flags)
{
struct vcpu_info *vcpu;
preempt_disable();
/* convert from IF type flag */
flags = !(flags & X86_EFLAGS_IF);
vcpu = x86_read_percpu(xen_vcpu);
vcpu->evtchn_upcall_mask = flags;
if (flags == 0) {
/* Unmask then check (avoid races). We're only protecting
against updates by this CPU, so there's no need for
anything stronger. */
barrier();
if (unlikely(vcpu->evtchn_upcall_pending))
force_evtchn_callback();
preempt_enable();
} else
preempt_enable_no_resched();
}
static void xen_irq_disable(void)
{
struct vcpu_info *vcpu;
preempt_disable();
vcpu = x86_read_percpu(xen_vcpu);
vcpu->evtchn_upcall_mask = 1;
preempt_enable_no_resched();
}
static void xen_irq_enable(void)
{
struct vcpu_info *vcpu;
preempt_disable();
vcpu = x86_read_percpu(xen_vcpu);
vcpu->evtchn_upcall_mask = 0;
/* Unmask then check (avoid races). We're only protecting
against updates by this CPU, so there's no need for
anything stronger. */
barrier();
if (unlikely(vcpu->evtchn_upcall_pending))
force_evtchn_callback();
preempt_enable();
}
static void xen_safe_halt(void)
{
/* Blocking includes an implicit local_irq_enable(). */
if (HYPERVISOR_sched_op(SCHEDOP_block, 0) != 0)
BUG();
}
static void xen_halt(void)
{
if (irqs_disabled())
HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
else
xen_safe_halt();
}
static void xen_set_lazy_mode(enum paravirt_lazy_mode mode)
{
switch (mode) {
case PARAVIRT_LAZY_NONE:
BUG_ON(x86_read_percpu(xen_lazy_mode) == PARAVIRT_LAZY_NONE);
break;
case PARAVIRT_LAZY_MMU:
case PARAVIRT_LAZY_CPU:
BUG_ON(x86_read_percpu(xen_lazy_mode) != PARAVIRT_LAZY_NONE);
break;
case PARAVIRT_LAZY_FLUSH:
/* flush if necessary, but don't change state */
if (x86_read_percpu(xen_lazy_mode) != PARAVIRT_LAZY_NONE)
xen_mc_flush();
return;
}
xen_mc_flush();
x86_write_percpu(xen_lazy_mode, mode);
}
static unsigned long xen_store_tr(void)
{
return 0;
}
static void xen_set_ldt(const void *addr, unsigned entries)
{
unsigned long linear_addr = (unsigned long)addr;
struct mmuext_op *op;
struct multicall_space mcs = xen_mc_entry(sizeof(*op));
op = mcs.args;
op->cmd = MMUEXT_SET_LDT;
if (linear_addr) {
/* ldt my be vmalloced, use arbitrary_virt_to_machine */
xmaddr_t maddr;
maddr = arbitrary_virt_to_machine((unsigned long)addr);
linear_addr = (unsigned long)maddr.maddr;
}
op->arg1.linear_addr = linear_addr;
op->arg2.nr_ents = entries;
MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
xen_mc_issue(PARAVIRT_LAZY_CPU);
}
static void xen_load_gdt(const struct Xgt_desc_struct *dtr)
{
unsigned long *frames;
unsigned long va = dtr->address;
unsigned int size = dtr->size + 1;
unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
int f;
struct multicall_space mcs;
/* A GDT can be up to 64k in size, which corresponds to 8192
8-byte entries, or 16 4k pages.. */
BUG_ON(size > 65536);
BUG_ON(va & ~PAGE_MASK);
mcs = xen_mc_entry(sizeof(*frames) * pages);
frames = mcs.args;
for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
frames[f] = virt_to_mfn(va);
make_lowmem_page_readonly((void *)va);
}
MULTI_set_gdt(mcs.mc, frames, size / sizeof(struct desc_struct));
xen_mc_issue(PARAVIRT_LAZY_CPU);
}
static void load_TLS_descriptor(struct thread_struct *t,
unsigned int cpu, unsigned int i)
{
struct desc_struct *gdt = get_cpu_gdt_table(cpu);
xmaddr_t maddr = virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
struct multicall_space mc = __xen_mc_entry(0);
MULTI_update_descriptor(mc.mc, maddr.maddr, t->tls_array[i]);
}
static void xen_load_tls(struct thread_struct *t, unsigned int cpu)
{
xen_mc_batch();
load_TLS_descriptor(t, cpu, 0);
load_TLS_descriptor(t, cpu, 1);
load_TLS_descriptor(t, cpu, 2);
xen_mc_issue(PARAVIRT_LAZY_CPU);
}
static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
u32 low, u32 high)
{
unsigned long lp = (unsigned long)&dt[entrynum];
xmaddr_t mach_lp = virt_to_machine(lp);
u64 entry = (u64)high << 32 | low;
xen_mc_flush();
if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
BUG();
}
static int cvt_gate_to_trap(int vector, u32 low, u32 high,
struct trap_info *info)
{
u8 type, dpl;
type = (high >> 8) & 0x1f;
dpl = (high >> 13) & 3;
if (type != 0xf && type != 0xe)
return 0;
info->vector = vector;
info->address = (high & 0xffff0000) | (low & 0x0000ffff);
info->cs = low >> 16;
info->flags = dpl;
/* interrupt gates clear IF */
if (type == 0xe)
info->flags |= 4;
return 1;
}
/* Locations of each CPU's IDT */
static DEFINE_PER_CPU(struct Xgt_desc_struct, idt_desc);
/* Set an IDT entry. If the entry is part of the current IDT, then
also update Xen. */
static void xen_write_idt_entry(struct desc_struct *dt, int entrynum,
u32 low, u32 high)
{
int cpu = smp_processor_id();
unsigned long p = (unsigned long)&dt[entrynum];
unsigned long start = per_cpu(idt_desc, cpu).address;
unsigned long end = start + per_cpu(idt_desc, cpu).size + 1;
xen_mc_flush();
write_dt_entry(dt, entrynum, low, high);
if (p >= start && (p + 8) <= end) {
struct trap_info info[2];
info[1].address = 0;
if (cvt_gate_to_trap(entrynum, low, high, &info[0]))
if (HYPERVISOR_set_trap_table(info))
BUG();
}
}
/* Load a new IDT into Xen. In principle this can be per-CPU, so we
hold a spinlock to protect the static traps[] array (static because
it avoids allocation, and saves stack space). */
static void xen_load_idt(const struct Xgt_desc_struct *desc)
{
static DEFINE_SPINLOCK(lock);
static struct trap_info traps[257];
int cpu = smp_processor_id();
unsigned in, out, count;
per_cpu(idt_desc, cpu) = *desc;
count = (desc->size+1) / 8;
BUG_ON(count > 256);
spin_lock(&lock);
for (in = out = 0; in < count; in++) {
const u32 *entry = (u32 *)(desc->address + in * 8);
if (cvt_gate_to_trap(in, entry[0], entry[1], &traps[out]))
out++;
}
traps[out].address = 0;
xen_mc_flush();
if (HYPERVISOR_set_trap_table(traps))
BUG();
spin_unlock(&lock);
}
/* Write a GDT descriptor entry. Ignore LDT descriptors, since
they're handled differently. */
static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
u32 low, u32 high)
{
switch ((high >> 8) & 0xff) {
case DESCTYPE_LDT:
case DESCTYPE_TSS:
/* ignore */
break;
default: {
xmaddr_t maddr = virt_to_machine(&dt[entry]);
u64 desc = (u64)high << 32 | low;
xen_mc_flush();
if (HYPERVISOR_update_descriptor(maddr.maddr, desc))
BUG();
}
}
}
static void xen_load_esp0(struct tss_struct *tss,
struct thread_struct *thread)
{
struct multicall_space mcs = xen_mc_entry(0);
MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->esp0);
xen_mc_issue(PARAVIRT_LAZY_CPU);
}
static void xen_set_iopl_mask(unsigned mask)
{
struct physdev_set_iopl set_iopl;
/* Force the change at ring 0. */
set_iopl.iopl = (mask == 0) ? 1 : (mask >> 12) & 3;
HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
}
static void xen_io_delay(void)
{
}
#ifdef CONFIG_X86_LOCAL_APIC
static unsigned long xen_apic_read(unsigned long reg)
{
return 0;
}
#endif
static void xen_flush_tlb(void)
{
struct mmuext_op op;
op.cmd = MMUEXT_TLB_FLUSH_LOCAL;
if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
BUG();
}
static void xen_flush_tlb_single(unsigned long addr)
{
struct mmuext_op op;
op.cmd = MMUEXT_INVLPG_LOCAL;
op.arg1.linear_addr = addr & PAGE_MASK;
if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
BUG();
}
static unsigned long xen_read_cr2(void)
{
return x86_read_percpu(xen_vcpu)->arch.cr2;
}
static void xen_write_cr4(unsigned long cr4)
{
/* never allow TSC to be disabled */
native_write_cr4(cr4 & ~X86_CR4_TSD);
}
/*
* Page-directory addresses above 4GB do not fit into architectural %cr3.
* When accessing %cr3, or equivalent field in vcpu_guest_context, guests
* must use the following accessor macros to pack/unpack valid MFNs.
*
* Note that Xen is using the fact that the pagetable base is always
* page-aligned, and putting the 12 MSB of the address into the 12 LSB
* of cr3.
*/
#define xen_pfn_to_cr3(pfn) (((unsigned)(pfn) << 12) | ((unsigned)(pfn) >> 20))
#define xen_cr3_to_pfn(cr3) (((unsigned)(cr3) >> 12) | ((unsigned)(cr3) << 20))
static unsigned long xen_read_cr3(void)
{
return x86_read_percpu(xen_cr3);
}
static void xen_write_cr3(unsigned long cr3)
{
if (cr3 == x86_read_percpu(xen_cr3)) {
/* just a simple tlb flush */
xen_flush_tlb();
return;
}
x86_write_percpu(xen_cr3, cr3);
{
struct mmuext_op *op;
struct multicall_space mcs = xen_mc_entry(sizeof(*op));
unsigned long mfn = pfn_to_mfn(PFN_DOWN(cr3));
op = mcs.args;
op->cmd = MMUEXT_NEW_BASEPTR;
op->arg1.mfn = mfn;
MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
xen_mc_issue(PARAVIRT_LAZY_CPU);
}
}
/* Early in boot, while setting up the initial pagetable, assume
everything is pinned. */
static __init void xen_alloc_pt_init(struct mm_struct *mm, u32 pfn)
{
BUG_ON(mem_map); /* should only be used early */
make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
}
/* This needs to make sure the new pte page is pinned iff its being
attached to a pinned pagetable. */
static void xen_alloc_pt(struct mm_struct *mm, u32 pfn)
{
struct page *page = pfn_to_page(pfn);
if (PagePinned(virt_to_page(mm->pgd))) {
SetPagePinned(page);
if (!PageHighMem(page))
make_lowmem_page_readonly(__va(PFN_PHYS(pfn)));
else
/* make sure there are no stray mappings of
this page */
kmap_flush_unused();
}
}
/* This should never happen until we're OK to use struct page */
static void xen_release_pt(u32 pfn)
{
struct page *page = pfn_to_page(pfn);
if (PagePinned(page)) {
if (!PageHighMem(page))
make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));
}
}
#ifdef CONFIG_HIGHPTE
static void *xen_kmap_atomic_pte(struct page *page, enum km_type type)
{
pgprot_t prot = PAGE_KERNEL;
if (PagePinned(page))
prot = PAGE_KERNEL_RO;
if (0 && PageHighMem(page))
printk("mapping highpte %lx type %d prot %s\n",
page_to_pfn(page), type,
(unsigned long)pgprot_val(prot) & _PAGE_RW ? "WRITE" : "READ");
return kmap_atomic_prot(page, type, prot);
}
#endif
static __init pte_t mask_rw_pte(pte_t *ptep, pte_t pte)
{
/* If there's an existing pte, then don't allow _PAGE_RW to be set */
if (pte_val_ma(*ptep) & _PAGE_PRESENT)
pte = __pte_ma(((pte_val_ma(*ptep) & _PAGE_RW) | ~_PAGE_RW) &
pte_val_ma(pte));
return pte;
}
/* Init-time set_pte while constructing initial pagetables, which
doesn't allow RO pagetable pages to be remapped RW */
static __init void xen_set_pte_init(pte_t *ptep, pte_t pte)
{
pte = mask_rw_pte(ptep, pte);
xen_set_pte(ptep, pte);
}
static __init void xen_pagetable_setup_start(pgd_t *base)
{
pgd_t *xen_pgd = (pgd_t *)xen_start_info->pt_base;
/* special set_pte for pagetable initialization */
paravirt_ops.set_pte = xen_set_pte_init;
init_mm.pgd = base;
/*
* copy top-level of Xen-supplied pagetable into place. For
* !PAE we can use this as-is, but for PAE it is a stand-in
* while we copy the pmd pages.
*/
memcpy(base, xen_pgd, PTRS_PER_PGD * sizeof(pgd_t));
if (PTRS_PER_PMD > 1) {
int i;
/*
* For PAE, need to allocate new pmds, rather than
* share Xen's, since Xen doesn't like pmd's being
* shared between address spaces.
*/
for (i = 0; i < PTRS_PER_PGD; i++) {
if (pgd_val_ma(xen_pgd[i]) & _PAGE_PRESENT) {
pmd_t *pmd = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);
memcpy(pmd, (void *)pgd_page_vaddr(xen_pgd[i]),
PAGE_SIZE);
make_lowmem_page_readonly(pmd);
set_pgd(&base[i], __pgd(1 + __pa(pmd)));
} else
pgd_clear(&base[i]);
}
}
/* make sure zero_page is mapped RO so we can use it in pagetables */
make_lowmem_page_readonly(empty_zero_page);
make_lowmem_page_readonly(base);
/*
* Switch to new pagetable. This is done before
* pagetable_init has done anything so that the new pages
* added to the table can be prepared properly for Xen.
*/
xen_write_cr3(__pa(base));
}
static __init void xen_pagetable_setup_done(pgd_t *base)
{
/* This will work as long as patching hasn't happened yet
(which it hasn't) */
paravirt_ops.alloc_pt = xen_alloc_pt;
paravirt_ops.set_pte = xen_set_pte;
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
/*
* Create a mapping for the shared info page.
* Should be set_fixmap(), but shared_info is a machine
* address with no corresponding pseudo-phys address.
*/
set_pte_mfn(fix_to_virt(FIX_PARAVIRT_BOOTMAP),
PFN_DOWN(xen_start_info->shared_info),
PAGE_KERNEL);
HYPERVISOR_shared_info =
(struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP);
} else
HYPERVISOR_shared_info =
(struct shared_info *)__va(xen_start_info->shared_info);
/* Actually pin the pagetable down, but we can't set PG_pinned
yet because the page structures don't exist yet. */
{
struct mmuext_op op;
#ifdef CONFIG_X86_PAE
op.cmd = MMUEXT_PIN_L3_TABLE;
#else
op.cmd = MMUEXT_PIN_L3_TABLE;
#endif
op.arg1.mfn = pfn_to_mfn(PFN_DOWN(__pa(base)));
if (HYPERVISOR_mmuext_op(&op, 1, NULL, DOMID_SELF))
BUG();
}
xen_vcpu_setup(smp_processor_id());
}
static const struct paravirt_ops xen_paravirt_ops __initdata = {
.paravirt_enabled = 1,
.shared_kernel_pmd = 0,
.name = "Xen",
.banner = xen_banner,
.patch = paravirt_patch_default,
.memory_setup = xen_memory_setup,
.arch_setup = xen_arch_setup,
.init_IRQ = xen_init_IRQ,
.post_allocator_init = xen_mark_init_mm_pinned,
.time_init = xen_time_init,
.set_wallclock = xen_set_wallclock,
.get_wallclock = xen_get_wallclock,
.get_cpu_khz = xen_cpu_khz,
.sched_clock = xen_clocksource_read,
.cpuid = xen_cpuid,
.set_debugreg = xen_set_debugreg,
.get_debugreg = xen_get_debugreg,
.clts = native_clts,
.read_cr0 = native_read_cr0,
.write_cr0 = native_write_cr0,
.read_cr2 = xen_read_cr2,
.write_cr2 = native_write_cr2,
.read_cr3 = xen_read_cr3,
.write_cr3 = xen_write_cr3,
.read_cr4 = native_read_cr4,
.read_cr4_safe = native_read_cr4_safe,
.write_cr4 = xen_write_cr4,
.save_fl = xen_save_fl,
.restore_fl = xen_restore_fl,
.irq_disable = xen_irq_disable,
.irq_enable = xen_irq_enable,
.safe_halt = xen_safe_halt,
.halt = xen_halt,
.wbinvd = native_wbinvd,
.read_msr = native_read_msr_safe,
.write_msr = native_write_msr_safe,
.read_tsc = native_read_tsc,
.read_pmc = native_read_pmc,
.iret = (void *)&hypercall_page[__HYPERVISOR_iret],
.irq_enable_sysexit = NULL, /* never called */
.load_tr_desc = paravirt_nop,
.set_ldt = xen_set_ldt,
.load_gdt = xen_load_gdt,
.load_idt = xen_load_idt,
.load_tls = xen_load_tls,
.store_gdt = native_store_gdt,
.store_idt = native_store_idt,
.store_tr = xen_store_tr,
.write_ldt_entry = xen_write_ldt_entry,
.write_gdt_entry = xen_write_gdt_entry,
.write_idt_entry = xen_write_idt_entry,
.load_esp0 = xen_load_esp0,
.set_iopl_mask = xen_set_iopl_mask,
.io_delay = xen_io_delay,
#ifdef CONFIG_X86_LOCAL_APIC
.apic_write = paravirt_nop,
.apic_write_atomic = paravirt_nop,
.apic_read = xen_apic_read,
.setup_boot_clock = paravirt_nop,
.setup_secondary_clock = paravirt_nop,
.startup_ipi_hook = paravirt_nop,
#endif
.flush_tlb_user = xen_flush_tlb,
.flush_tlb_kernel = xen_flush_tlb,
.flush_tlb_single = xen_flush_tlb_single,
.pte_update = paravirt_nop,
.pte_update_defer = paravirt_nop,
.pagetable_setup_start = xen_pagetable_setup_start,
.pagetable_setup_done = xen_pagetable_setup_done,
.alloc_pt = xen_alloc_pt_init,
.release_pt = xen_release_pt,
.alloc_pd = paravirt_nop,
.alloc_pd_clone = paravirt_nop,
.release_pd = paravirt_nop,
#ifdef CONFIG_HIGHPTE
.kmap_atomic_pte = xen_kmap_atomic_pte,
#endif
.set_pte = NULL, /* see xen_pagetable_setup_* */
.set_pte_at = xen_set_pte_at,
.set_pmd = xen_set_pmd,
.pte_val = xen_pte_val,
.pgd_val = xen_pgd_val,
.make_pte = xen_make_pte,
.make_pgd = xen_make_pgd,
#ifdef CONFIG_X86_PAE
.set_pte_atomic = xen_set_pte_atomic,
.set_pte_present = xen_set_pte_at,
.set_pud = xen_set_pud,
.pte_clear = xen_pte_clear,
.pmd_clear = xen_pmd_clear,
.make_pmd = xen_make_pmd,
.pmd_val = xen_pmd_val,
#endif /* PAE */
.activate_mm = xen_activate_mm,
.dup_mmap = xen_dup_mmap,
.exit_mmap = xen_exit_mmap,
.set_lazy_mode = xen_set_lazy_mode,
};
/* First C function to be called on Xen boot */
asmlinkage void __init xen_start_kernel(void)
{
pgd_t *pgd;
if (!xen_start_info)
return;
BUG_ON(memcmp(xen_start_info->magic, "xen-3.0", 7) != 0);
/* Install Xen paravirt ops */
paravirt_ops = xen_paravirt_ops;
xen_setup_features();
/* Get mfn list */
if (!xen_feature(XENFEAT_auto_translated_physmap))
phys_to_machine_mapping = (unsigned long *)xen_start_info->mfn_list;
pgd = (pgd_t *)xen_start_info->pt_base;
init_pg_tables_end = __pa(pgd) + xen_start_info->nr_pt_frames*PAGE_SIZE;
init_mm.pgd = pgd; /* use the Xen pagetables to start */
/* keep using Xen gdt for now; no urgent need to change it */
x86_write_percpu(xen_cr3, __pa(pgd));
xen_vcpu_setup(0);
paravirt_ops.kernel_rpl = 1;
if (xen_feature(XENFEAT_supervisor_mode_kernel))
paravirt_ops.kernel_rpl = 0;
/* set the limit of our address space */
reserve_top_address(-HYPERVISOR_VIRT_START + 2 * PAGE_SIZE);
/* set up basic CPUID stuff */
cpu_detect(&new_cpu_data);
new_cpu_data.hard_math = 1;
new_cpu_data.x86_capability[0] = cpuid_edx(1);
/* Poke various useful things into boot_params */
LOADER_TYPE = (9 << 4) | 0;
INITRD_START = xen_start_info->mod_start ? __pa(xen_start_info->mod_start) : 0;
INITRD_SIZE = xen_start_info->mod_len;
/* Start the world */
start_kernel();
}