/*
* 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/hardirq.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 <linux/smp.h>
#include <xen/interface/xen.h>
#include <xen/interface/physdev.h>
#include <xen/interface/vcpu.h>
#include <xen/interface/sched.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 <asm/tlbflush.h>
#include <asm/reboot.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 /* __initdata */ struct shared_info dummy_shared_info;
/*
* Point at some empty memory to start with. We map the real shared_info
* page as soon as fixmap is up and running.
*/
struct shared_info *HYPERVISOR_shared_info = (void *)&dummy_shared_info;
/*
* Flag to determine whether vcpu info placement is available on all
* VCPUs. We assume it is to start with, and then set it to zero on
* the first failure. This is because it can succeed on some VCPUs
* and not others, since it can involve hypervisor memory allocation,
* or because the guest failed to guarantee all the appropriate
* constraints on all VCPUs (ie buffer can't cross a page boundary).
*
* Note that any particular CPU may be using a placed vcpu structure,
* but we can only optimise if the all are.
*
* 0: not available, 1: available
*/
static int have_vcpu_info_placement = 1;
static void __init xen_vcpu_setup(int cpu)
{
struct vcpu_register_vcpu_info info;
int err;
struct vcpu_info *vcpup;
per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
if (!have_vcpu_info_placement)
return; /* already tested, not available */
vcpup = &per_cpu(xen_vcpu_info, cpu);
info.mfn = virt_to_mfn(vcpup);
info.offset = offset_in_page(vcpup);
printk(KERN_DEBUG "trying to map vcpu_info %d at %p, mfn %x, offset %d\n",
cpu, vcpup, info.mfn, info.offset);
/* Check to see if the hypervisor will put the vcpu_info
structure where we want it, which allows direct access via
a percpu-variable. */
err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info);
if (err) {
printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
have_vcpu_info_placement = 0;
} else {
/* This cpu is using the registered vcpu info, even if
later ones fail to. */
per_cpu(xen_vcpu, cpu) = vcpup;
printk(KERN_DEBUG "cpu %d using vcpu_info at %p\n",
cpu, vcpup);
}
}
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;
vcpu = x86_read_percpu(xen_vcpu);
/* flag has opposite sense of mask */
flags = !vcpu->evtchn_upcall_mask;
/* 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;
/* convert from IF type flag */
flags = !(flags & X86_EFLAGS_IF);
/* There's a one instruction preempt window here. We need to
make sure we're don't switch CPUs between getting the vcpu
pointer and updating the mask. */
preempt_disable();
vcpu = x86_read_percpu(xen_vcpu);
vcpu->evtchn_upcall_mask = flags;
preempt_enable_no_resched();
/* Doesn't matter if we get preempted here, because any
pending event will get dealt with anyway. */
if (flags == 0) {
preempt_check_resched();
barrier(); /* unmask then check (avoid races) */
if (unlikely(vcpu->evtchn_upcall_pending))
force_evtchn_callback();
}
}
static void xen_irq_disable(void)
{
/* There's a one instruction preempt window here. We need to
make sure we're don't switch CPUs between getting the vcpu
pointer and updating the mask. */
preempt_disable();
x86_read_percpu(xen_vcpu)->evtchn_upcall_mask = 1;
preempt_enable_no_resched();
}
static void xen_irq_enable(void)
{
struct vcpu_info *vcpu;
/* There's a one instruction preempt window here. We need to
make sure we're don't switch CPUs between getting the vcpu
pointer and updating the mask. */
preempt_disable();
vcpu = x86_read_percpu(xen_vcpu);
vcpu->evtchn_upcall_mask = 0;
preempt_enable_no_resched();
/* Doesn't matter if we get preempted here, because any
pending event will get dealt with anyway. */
barrier(); /* unmask then check (avoid races) */
if (unlikely(vcpu->evtchn_upcall_pending))
force_evtchn_callback();
}
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)
{
BUG_ON(preemptible());
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);
/*
* XXX sleazy hack: If we're being called in a lazy-cpu zone,
* it means we're in a context switch, and %gs has just been
* saved. This means we can zero it out to prevent faults on
* exit from the hypervisor if the next process has no %gs.
* Either way, it has been saved, and the new value will get
* loaded properly. This will go away as soon as Xen has been
* modified to not save/restore %gs for normal hypercalls.
*/
if (xen_get_lazy_mode() == PARAVIRT_LAZY_CPU)
loadsegment(gs, 0);
}
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;
preempt_disable();
xen_mc_flush();
if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
BUG();
preempt_enable();
}
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)
{
unsigned long p = (unsigned long)&dt[entrynum];
unsigned long start, end;
preempt_disable();
start = __get_cpu_var(idt_desc).address;
end = start + __get_cpu_var(idt_desc).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();
}
preempt_enable();
}
static void xen_convert_trap_info(const struct Xgt_desc_struct *desc,
struct trap_info *traps)
{
unsigned in, out, count;
count = (desc->size+1) / 8;
BUG_ON(count > 256);
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;
}
void xen_copy_trap_info(struct trap_info *traps)
{
const struct Xgt_desc_struct *desc = &__get_cpu_var(idt_desc);
xen_convert_trap_info(desc, traps);
}
/* 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];
spin_lock(&lock);
__get_cpu_var(idt_desc) = *desc;
xen_convert_trap_info(desc, traps);
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)
{
preempt_disable();
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();
}
}
preempt_enable();
}
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;
}
static void xen_apic_write(unsigned long reg, unsigned long val)
{
/* Warn to see if there's any stray references */
WARN_ON(1);
}
#endif
static void xen_flush_tlb(void)
{
struct mmuext_op *op;
struct multicall_space mcs = xen_mc_entry(sizeof(*op));
op = mcs.args;
op->cmd = MMUEXT_TLB_FLUSH_LOCAL;
MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
xen_mc_issue(PARAVIRT_LAZY_MMU);
}
static void xen_flush_tlb_single(unsigned long addr)
{
struct mmuext_op *op;
struct multicall_space mcs = xen_mc_entry(sizeof(*op));
op = mcs.args;
op->cmd = MMUEXT_INVLPG_LOCAL;
op->arg1.linear_addr = addr & PAGE_MASK;
MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
xen_mc_issue(PARAVIRT_LAZY_MMU);
}
static void xen_flush_tlb_others(const cpumask_t *cpus, struct mm_struct *mm,
unsigned long va)
{
struct {
struct mmuext_op op;
cpumask_t mask;
} *args;
cpumask_t cpumask = *cpus;
struct multicall_space mcs;
/*
* A couple of (to be removed) sanity checks:
*
* - current CPU must not be in mask
* - mask must exist :)
*/
BUG_ON(cpus_empty(cpumask));
BUG_ON(cpu_isset(smp_processor_id(), cpumask));
BUG_ON(!mm);
/* If a CPU which we ran on has gone down, OK. */
cpus_and(cpumask, cpumask, cpu_online_map);
if (cpus_empty(cpumask))
return;
mcs = xen_mc_entry(sizeof(*args));
args = mcs.args;
args->mask = cpumask;
args->op.arg2.vcpumask = &args->mask;
if (va == TLB_FLUSH_ALL) {
args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
} else {
args->op.cmd = MMUEXT_INVLPG_MULTI;
args->op.arg1.linear_addr = va;
}
MULTI_mmuext_op(mcs.mc, &args->op, 1, NULL, DOMID_SELF);
xen_mc_issue(PARAVIRT_LAZY_MMU);
}
static void xen_write_cr2(unsigned long cr2)
{
x86_read_percpu(xen_vcpu)->arch.cr2 = cr2;
}
static unsigned long xen_read_cr2(void)
{
return x86_read_percpu(xen_vcpu)->arch.cr2;
}
static unsigned long xen_read_cr2_direct(void)
{
return x86_read_percpu(xen_vcpu_info.arch.cr2);
}
static void xen_write_cr4(unsigned long cr4)
{
/* Just ignore cr4 changes; Xen doesn't allow us to do
anything anyway. */
}
static unsigned long xen_read_cr3(void)
{
return x86_read_percpu(xen_cr3);
}
static void xen_write_cr3(unsigned long cr3)
{
BUG_ON(preemptible());
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();
}
}
/* This is called once we have the cpu_possible_map */
void __init xen_setup_vcpu_info_placement(void)
{
int cpu;
for_each_possible_cpu(cpu)
xen_vcpu_setup(cpu);
/* xen_vcpu_setup managed to place the vcpu_info within the
percpu area for all cpus, so make use of it */
if (have_vcpu_info_placement) {
printk(KERN_INFO "Xen: using vcpu_info placement\n");
paravirt_ops.save_fl = xen_save_fl_direct;
paravirt_ops.restore_fl = xen_restore_fl_direct;
paravirt_ops.irq_disable = xen_irq_disable_direct;
paravirt_ops.irq_enable = xen_irq_enable_direct;
paravirt_ops.read_cr2 = xen_read_cr2_direct;
paravirt_ops.iret = xen_iret_direct;
}
}
static unsigned xen_patch(u8 type, u16 clobbers, void *insnbuf,
unsigned long addr, unsigned len)
{
char *start, *end, *reloc;
unsigned ret;
start = end = reloc = NULL;
#define SITE(x) \
case PARAVIRT_PATCH(x): \
if (have_vcpu_info_placement) { \
start = (char *)xen_##x##_direct; \
end = xen_##x##_direct_end; \
reloc = xen_##x##_direct_reloc; \
} \
goto patch_site
switch (type) {
SITE(irq_enable);
SITE(irq_disable);
SITE(save_fl);
SITE(restore_fl);
#undef SITE
patch_site:
if (start == NULL || (end-start) > len)
goto default_patch;
ret = paravirt_patch_insns(insnbuf, len, start, end);
/* Note: because reloc is assigned from something that
appears to be an array, gcc assumes it's non-null,
but doesn't know its relationship with start and
end. */
if (reloc > start && reloc < end) {
int reloc_off = reloc - start;
long *relocp = (long *)(insnbuf + reloc_off);
long delta = start - (char *)addr;
*relocp += delta;
}
break;
default_patch:
default:
ret = paravirt_patch_default(type, clobbers, insnbuf,
addr, len);
break;
}
return ret;
}
static const struct paravirt_ops xen_paravirt_ops __initdata = {
.paravirt_enabled = 1,
.shared_kernel_pmd = 0,
.name = "Xen",
.banner = xen_banner,
.patch = xen_patch,
.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_sched_clock,
.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 = xen_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 = xen_apic_write,
.apic_write_atomic = xen_apic_write,
.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,
.flush_tlb_others = xen_flush_tlb_others,
.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,
};
#ifdef CONFIG_SMP
static const struct smp_ops xen_smp_ops __initdata = {
.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
.smp_prepare_cpus = xen_smp_prepare_cpus,
.cpu_up = xen_cpu_up,
.smp_cpus_done = xen_smp_cpus_done,
.smp_send_stop = xen_smp_send_stop,
.smp_send_reschedule = xen_smp_send_reschedule,
.smp_call_function_mask = xen_smp_call_function_mask,
};
#endif /* CONFIG_SMP */
static void xen_reboot(int reason)
{
#ifdef CONFIG_SMP
smp_send_stop();
#endif
if (HYPERVISOR_sched_op(SCHEDOP_shutdown, reason))
BUG();
}
static void xen_restart(char *msg)
{
xen_reboot(SHUTDOWN_reboot);
}
static void xen_emergency_restart(void)
{
xen_reboot(SHUTDOWN_reboot);
}
static void xen_machine_halt(void)
{
xen_reboot(SHUTDOWN_poweroff);
}
static void xen_crash_shutdown(struct pt_regs *regs)
{
xen_reboot(SHUTDOWN_crash);
}
static const struct machine_ops __initdata xen_machine_ops = {
.restart = xen_restart,
.halt = xen_machine_halt,
.power_off = xen_machine_halt,
.shutdown = xen_machine_halt,
.crash_shutdown = xen_crash_shutdown,
.emergency_restart = xen_emergency_restart,
};
/* 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;
machine_ops = xen_machine_ops;
#ifdef CONFIG_SMP
smp_ops = xen_smp_ops;
#endif
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));
#ifdef CONFIG_SMP
/* Don't do the full vcpu_info placement stuff until we have a
possible map. */
per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
#else
/* May as well do it now, since there's no good time to call
it later on UP. */
xen_setup_vcpu_info_placement();
#endif
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();
}
