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/*
* 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/cpu.h>
#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/kprobes.h>
#include <linux/bootmem.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/page-flags.h>
#include <linux/highmem.h>
#include <linux/console.h>
#include <linux/pci.h>
#include <linux/gfp.h>
#include <linux/memblock.h>
#include <xen/xen.h>
#include <xen/events.h>
#include <xen/interface/xen.h>
#include <xen/interface/version.h>
#include <xen/interface/physdev.h>
#include <xen/interface/vcpu.h>
#include <xen/interface/memory.h>
#include <xen/interface/xen-mca.h>
#include <xen/features.h>
#include <xen/page.h>
#include <xen/hvm.h>
#include <xen/hvc-console.h>
#include <xen/acpi.h>
#include <asm/paravirt.h>
#include <asm/apic.h>
#include <asm/page.h>
#include <asm/xen/pci.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>
#include <asm/fixmap.h>
#include <asm/processor.h>
#include <asm/proto.h>
#include <asm/msr-index.h>
#include <asm/traps.h>
#include <asm/setup.h>
#include <asm/desc.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/reboot.h>
#include <asm/stackprotector.h>
#include <asm/hypervisor.h>
#include <asm/mwait.h>
#include <asm/pci_x86.h>
#ifdef CONFIG_ACPI
#include <linux/acpi.h>
#include <asm/acpi.h>
#include <acpi/pdc_intel.h>
#include <acpi/processor.h>
#include <xen/interface/platform.h>
#endif
#include "xen-ops.h"
#include "mmu.h"
#include "smp.h"
#include "multicalls.h"
EXPORT_SYMBOL_GPL(hypercall_page);
DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
enum xen_domain_type xen_domain_type = XEN_NATIVE;
EXPORT_SYMBOL_GPL(xen_domain_type);
unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START;
EXPORT_SYMBOL(machine_to_phys_mapping);
unsigned long machine_to_phys_nr;
EXPORT_SYMBOL(machine_to_phys_nr);
struct start_info *xen_start_info;
EXPORT_SYMBOL_GPL(xen_start_info);
struct shared_info xen_dummy_shared_info;
void *xen_initial_gdt;
RESERVE_BRK(shared_info_page_brk, PAGE_SIZE);
__read_mostly int xen_have_vector_callback;
EXPORT_SYMBOL_GPL(xen_have_vector_callback);
/*
* 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 = &xen_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;
struct tls_descs {
struct desc_struct desc[3];
};
/*
* Updating the 3 TLS descriptors in the GDT on every task switch is
* surprisingly expensive so we avoid updating them if they haven't
* changed. Since Xen writes different descriptors than the one
* passed in the update_descriptor hypercall we keep shadow copies to
* compare against.
*/
static DEFINE_PER_CPU(struct tls_descs, shadow_tls_desc);
static void clamp_max_cpus(void)
{
#ifdef CONFIG_SMP
if (setup_max_cpus > MAX_VIRT_CPUS)
setup_max_cpus = MAX_VIRT_CPUS;
#endif
}
static void xen_vcpu_setup(int cpu)
{
struct vcpu_register_vcpu_info info;
int err;
struct vcpu_info *vcpup;
BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info);
if (cpu < MAX_VIRT_CPUS)
per_cpu(xen_vcpu,cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
if (!have_vcpu_info_placement) {
if (cpu >= MAX_VIRT_CPUS)
clamp_max_cpus();
return;
}
vcpup = &per_cpu(xen_vcpu_info, cpu);
info.mfn = arbitrary_virt_to_mfn(vcpup);
info.offset = offset_in_page(vcpup);
/* 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;
clamp_max_cpus();
} else {
/* This cpu is using the registered vcpu info, even if
later ones fail to. */
per_cpu(xen_vcpu, cpu) = vcpup;
}
}
/*
* On restore, set the vcpu placement up again.
* If it fails, then we're in a bad state, since
* we can't back out from using it...
*/
void xen_vcpu_restore(void)
{
int cpu;
for_each_possible_cpu(cpu) {
bool other_cpu = (cpu != smp_processor_id());
bool is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL);
if (other_cpu && is_up &&
HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL))
BUG();
xen_setup_runstate_info(cpu);
if (have_vcpu_info_placement)
xen_vcpu_setup(cpu);
if (other_cpu && is_up &&
HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL))
BUG();
}
}
static void __init xen_banner(void)
{
unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL);
struct xen_extraversion extra;
HYPERVISOR_xen_version(XENVER_extraversion, &extra);
printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
pv_info.name);
printk(KERN_INFO "Xen version: %d.%d%s%s\n",
version >> 16, version & 0xffff, extra.extraversion,
xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : "");
}
/* Check if running on Xen version (major, minor) or later */
bool
xen_running_on_version_or_later(unsigned int major, unsigned int minor)
{
unsigned int version;
if (!xen_domain())
return false;
version = HYPERVISOR_xen_version(XENVER_version, NULL);
if ((((version >> 16) == major) && ((version & 0xffff) >= minor)) ||
((version >> 16) > major))
return true;
return false;
}
#define CPUID_THERM_POWER_LEAF 6
#define APERFMPERF_PRESENT 0
static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
static __read_mostly unsigned int cpuid_leaf1_ecx_set_mask;
static __read_mostly unsigned int cpuid_leaf5_ecx_val;
static __read_mostly unsigned int cpuid_leaf5_edx_val;
static void xen_cpuid(unsigned int *ax, unsigned int *bx,
unsigned int *cx, unsigned int *dx)
{
unsigned maskebx = ~0;
unsigned maskecx = ~0;
unsigned maskedx = ~0;
unsigned setecx = 0;
/*
* Mask out inconvenient features, to try and disable as many
* unsupported kernel subsystems as possible.
*/
switch (*ax) {
case 1:
maskecx = cpuid_leaf1_ecx_mask;
setecx = cpuid_leaf1_ecx_set_mask;
maskedx = cpuid_leaf1_edx_mask;
break;
case CPUID_MWAIT_LEAF:
/* Synthesize the values.. */
*ax = 0;
*bx = 0;
*cx = cpuid_leaf5_ecx_val;
*dx = cpuid_leaf5_edx_val;
return;
case CPUID_THERM_POWER_LEAF:
/* Disabling APERFMPERF for kernel usage */
maskecx = ~(1 << APERFMPERF_PRESENT);
break;
case 0xb:
/* Suppress extended topology stuff */
maskebx = 0;
break;
}
asm(XEN_EMULATE_PREFIX "cpuid"
: "=a" (*ax),
"=b" (*bx),
"=c" (*cx),
"=d" (*dx)
: "0" (*ax), "2" (*cx));
*bx &= maskebx;
*cx &= maskecx;
*cx |= setecx;
*dx &= maskedx;
}
static bool __init xen_check_mwait(void)
{
#ifdef CONFIG_ACPI
struct xen_platform_op op = {
.cmd = XENPF_set_processor_pminfo,
.u.set_pminfo.id = -1,
.u.set_pminfo.type = XEN_PM_PDC,
};
uint32_t buf[3];
unsigned int ax, bx, cx, dx;
unsigned int mwait_mask;
/* We need to determine whether it is OK to expose the MWAIT
* capability to the kernel to harvest deeper than C3 states from ACPI
* _CST using the processor_harvest_xen.c module. For this to work, we
* need to gather the MWAIT_LEAF values (which the cstate.c code
* checks against). The hypervisor won't expose the MWAIT flag because
* it would break backwards compatibility; so we will find out directly
* from the hardware and hypercall.
*/
if (!xen_initial_domain())
return false;
/*
* When running under platform earlier than Xen4.2, do not expose
* mwait, to avoid the risk of loading native acpi pad driver
*/
if (!xen_running_on_version_or_later(4, 2))
return false;
ax = 1;
cx = 0;
native_cpuid(&ax, &bx, &cx, &dx);
mwait_mask = (1 << (X86_FEATURE_EST % 32)) |
(1 << (X86_FEATURE_MWAIT % 32));
if ((cx & mwait_mask) != mwait_mask)
return false;
/* We need to emulate the MWAIT_LEAF and for that we need both
* ecx and edx. The hypercall provides only partial information.
*/
ax = CPUID_MWAIT_LEAF;
bx = 0;
cx = 0;
dx = 0;
native_cpuid(&ax, &bx, &cx, &dx);
/* Ask the Hypervisor whether to clear ACPI_PDC_C_C2C3_FFH. If so,
* don't expose MWAIT_LEAF and let ACPI pick the IOPORT version of C3.
*/
buf[0] = ACPI_PDC_REVISION_ID;
buf[1] = 1;
buf[2] = (ACPI_PDC_C_CAPABILITY_SMP | ACPI_PDC_EST_CAPABILITY_SWSMP);
set_xen_guest_handle(op.u.set_pminfo.pdc, buf);
if ((HYPERVISOR_dom0_op(&op) == 0) &&
(buf[2] & (ACPI_PDC_C_C1_FFH | ACPI_PDC_C_C2C3_FFH))) {
cpuid_leaf5_ecx_val = cx;
cpuid_leaf5_edx_val = dx;
}
return true;
#else
return false;
#endif
}
static void __init xen_init_cpuid_mask(void)
{
unsigned int ax, bx, cx, dx;
unsigned int xsave_mask;
cpuid_leaf1_edx_mask =
~((1 << X86_FEATURE_MTRR) | /* disable MTRR */
(1 << X86_FEATURE_ACC)); /* thermal monitoring */
if (!xen_initial_domain())
cpuid_leaf1_edx_mask &=
~((1 << X86_FEATURE_APIC) | /* disable local APIC */
(1 << X86_FEATURE_ACPI)); /* disable ACPI */
ax = 1;
cx = 0;
xen_cpuid(&ax, &bx, &cx, &dx);
xsave_mask =
(1 << (X86_FEATURE_XSAVE % 32)) |
(1 << (X86_FEATURE_OSXSAVE % 32));
/* Xen will set CR4.OSXSAVE if supported and not disabled by force */
if ((cx & xsave_mask) != xsave_mask)
cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */
if (xen_check_mwait())
cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32));
}
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 void xen_end_context_switch(struct task_struct *next)
{
xen_mc_flush();
paravirt_end_context_switch(next);
}
static unsigned long xen_store_tr(void)
{
return 0;
}
/*
* Set the page permissions for a particular virtual address. If the
* address is a vmalloc mapping (or other non-linear mapping), then
* find the linear mapping of the page and also set its protections to
* match.
*/
static void set_aliased_prot(void *v, pgprot_t prot)
{
int level;
pte_t *ptep;
pte_t pte;
unsigned long pfn;
struct page *page;
ptep = lookup_address((unsigned long)v, &level);
BUG_ON(ptep == NULL);
pfn = pte_pfn(*ptep);
page = pfn_to_page(pfn);
pte = pfn_pte(pfn, prot);
if (HYPERVISOR_update_va_mapping((unsigned long)v, pte, 0))
BUG();
if (!PageHighMem(page)) {
void *av = __va(PFN_PHYS(pfn));
if (av != v)
if (HYPERVISOR_update_va_mapping((unsigned long)av, pte, 0))
BUG();
} else
kmap_flush_unused();
}
static void xen_alloc_ldt(struct desc_struct *ldt, unsigned entries)
{
const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
int i;
for(i = 0; i < entries; i += entries_per_page)
set_aliased_prot(ldt + i, PAGE_KERNEL_RO);
}
static void xen_free_ldt(struct desc_struct *ldt, unsigned entries)
{
const unsigned entries_per_page = PAGE_SIZE / LDT_ENTRY_SIZE;
int i;
for(i = 0; i < entries; i += entries_per_page)
set_aliased_prot(ldt + i, PAGE_KERNEL);
}
static void xen_set_ldt(const void *addr, unsigned entries)
{
struct mmuext_op *op;
struct multicall_space mcs = xen_mc_entry(sizeof(*op));
trace_xen_cpu_set_ldt(addr, entries);
op = mcs.args;
op->cmd = MMUEXT_SET_LDT;
op->arg1.linear_addr = (unsigned long)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 desc_ptr *dtr)
{
unsigned long va = dtr->address;
unsigned int size = dtr->size + 1;
unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
unsigned long frames[pages];
int f;
/*
* 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);
for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
int level;
pte_t *ptep;
unsigned long pfn, mfn;
void *virt;
/*
* The GDT is per-cpu and is in the percpu data area.
* That can be virtually mapped, so we need to do a
* page-walk to get the underlying MFN for the
* hypercall. The page can also be in the kernel's
* linear range, so we need to RO that mapping too.
*/
ptep = lookup_address(va, &level);
BUG_ON(ptep == NULL);
pfn = pte_pfn(*ptep);
mfn = pfn_to_mfn(pfn);
virt = __va(PFN_PHYS(pfn));
frames[f] = mfn;
make_lowmem_page_readonly((void *)va);
make_lowmem_page_readonly(virt);
}
if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
BUG();
}
/*
* load_gdt for early boot, when the gdt is only mapped once
*/
static void __init xen_load_gdt_boot(const struct desc_ptr *dtr)
{
unsigned long va = dtr->address;
unsigned int size = dtr->size + 1;
unsigned pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
unsigned long frames[pages];
int f;
/*
* 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);
for (f = 0; va < dtr->address + size; va += PAGE_SIZE, f++) {
pte_t pte;
unsigned long pfn, mfn;
pfn = virt_to_pfn(va);
mfn = pfn_to_mfn(pfn);
pte = pfn_pte(pfn, PAGE_KERNEL_RO);
if (HYPERVISOR_update_va_mapping((unsigned long)va, pte, 0))
BUG();
frames[f] = mfn;
}
if (HYPERVISOR_set_gdt(frames, size / sizeof(struct desc_struct)))
BUG();
}
static inline bool desc_equal(const struct desc_struct *d1,
const struct desc_struct *d2)
{
return d1->a == d2->a && d1->b == d2->b;
}
static void load_TLS_descriptor(struct thread_struct *t,
unsigned int cpu, unsigned int i)
{
struct desc_struct *shadow = &per_cpu(shadow_tls_desc, cpu).desc[i];
struct desc_struct *gdt;
xmaddr_t maddr;
struct multicall_space mc;
if (desc_equal(shadow, &t->tls_array[i]))
return;
*shadow = t->tls_array[i];
gdt = get_cpu_gdt_table(cpu);
maddr = arbitrary_virt_to_machine(&gdt[GDT_ENTRY_TLS_MIN+i]);
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)
{
/*
* XXX sleazy hack: If we're being called in a lazy-cpu zone
* and lazy gs handling is enabled, 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.
*
* On x86_64, this hack is not used for %gs, because gs points
* to KERNEL_GS_BASE (and uses it for PDA references), so we
* must not zero %gs on x86_64
*
* For x86_64, we need to zero %fs, otherwise we may get an
* exception between the new %fs descriptor being loaded and
* %fs being effectively cleared at __switch_to().
*/
if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) {
#ifdef CONFIG_X86_32
lazy_load_gs(0);
#else
loadsegment(fs, 0);
#endif
}
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);
}
#ifdef CONFIG_X86_64
static void xen_load_gs_index(unsigned int idx)
{
if (HYPERVISOR_set_segment_base(SEGBASE_GS_USER_SEL, idx))
BUG();
}
#endif
static void xen_write_ldt_entry(struct desc_struct *dt, int entrynum,
const void *ptr)
{
xmaddr_t mach_lp = arbitrary_virt_to_machine(&dt[entrynum]);
u64 entry = *(u64 *)ptr;
trace_xen_cpu_write_ldt_entry(dt, entrynum, entry);
preempt_disable();
xen_mc_flush();
if (HYPERVISOR_update_descriptor(mach_lp.maddr, entry))
BUG();
preempt_enable();
}
static int cvt_gate_to_trap(int vector, const gate_desc *val,
struct trap_info *info)
{
unsigned long addr;
if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT)
return 0;
info->vector = vector;
addr = gate_offset(*val);
#ifdef CONFIG_X86_64
/*
* Look for known traps using IST, and substitute them
* appropriately. The debugger ones are the only ones we care
* about. Xen will handle faults like double_fault,
* so we should never see them. Warn if
* there's an unexpected IST-using fault handler.
*/
if (addr == (unsigned long)debug)
addr = (unsigned long)xen_debug;
else if (addr == (unsigned long)int3)
addr = (unsigned long)xen_int3;
else if (addr == (unsigned long)stack_segment)
addr = (unsigned long)xen_stack_segment;
else if (addr == (unsigned long)double_fault ||
addr == (unsigned long)nmi) {
/* Don't need to handle these */
return 0;
#ifdef CONFIG_X86_MCE
} else if (addr == (unsigned long)machine_check) {
/*
* when xen hypervisor inject vMCE to guest,
* use native mce handler to handle it
*/
;
#endif
} else {
/* Some other trap using IST? */
if (WARN_ON(val->ist != 0))
return 0;
}
#endif /* CONFIG_X86_64 */
info->address = addr;
info->cs = gate_segment(*val);
info->flags = val->dpl;
/* interrupt gates clear IF */
if (val->type == GATE_INTERRUPT)
info->flags |= 1 << 2;
return 1;
}
/* Locations of each CPU's IDT */
static DEFINE_PER_CPU(struct desc_ptr, 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(gate_desc *dt, int entrynum, const gate_desc *g)
{
unsigned long p = (unsigned long)&dt[entrynum];
unsigned long start, end;
trace_xen_cpu_write_idt_entry(dt, entrynum, g);
preempt_disable();
start = __this_cpu_read(idt_desc.address);
end = start + __this_cpu_read(idt_desc.size) + 1;
xen_mc_flush();
native_write_idt_entry(dt, entrynum, g);
if (p >= start && (p + 8) <= end) {
struct trap_info info[2];
info[1].address = 0;
if (cvt_gate_to_trap(entrynum, g, &info[0]))
if (HYPERVISOR_set_trap_table(info))
BUG();
}
preempt_enable();
}
static void xen_convert_trap_info(const struct desc_ptr *desc,
struct trap_info *traps)
{
unsigned in, out, count;
count = (desc->size+1) / sizeof(gate_desc);
BUG_ON(count > 256);
for (in = out = 0; in < count; in++) {
gate_desc *entry = (gate_desc*)(desc->address) + in;
if (cvt_gate_to_trap(in, entry, &traps[out]))
out++;
}
traps[out].address = 0;
}
void xen_copy_trap_info(struct trap_info *traps)
{
const struct desc_ptr *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 desc_ptr *desc)
{
static DEFINE_SPINLOCK(lock);
static struct trap_info traps[257];
trace_xen_cpu_load_idt(desc);
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,
const void *desc, int type)
{
trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
preempt_disable();
switch (type) {
case DESC_LDT:
case DESC_TSS:
/* ignore */
break;
default: {
xmaddr_t maddr = arbitrary_virt_to_machine(&dt[entry]);
xen_mc_flush();
if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
BUG();
}
}
preempt_enable();
}
/*
* Version of write_gdt_entry for use at early boot-time needed to
* update an entry as simply as possible.
*/
static void __init xen_write_gdt_entry_boot(struct desc_struct *dt, int entry,
const void *desc, int type)
{
trace_xen_cpu_write_gdt_entry(dt, entry, desc, type);
switch (type) {
case DESC_LDT:
case DESC_TSS:
/* ignore */
break;
default: {
xmaddr_t maddr = virt_to_machine(&dt[entry]);
if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
dt[entry] = *(struct desc_struct *)desc;
}
}
}
static void xen_load_sp0(struct tss_struct *tss,
struct thread_struct *thread)
{
struct multicall_space mcs;
mcs = xen_mc_entry(0);
MULTI_stack_switch(mcs.mc, __KERNEL_DS, thread->sp0);
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_set_apic_id(unsigned int x)
{
WARN_ON(1);
return x;
}
static unsigned int xen_get_apic_id(unsigned long x)
{
return ((x)>>24) & 0xFFu;
}
static u32 xen_apic_read(u32 reg)
{
struct xen_platform_op op = {
.cmd = XENPF_get_cpuinfo,
.interface_version = XENPF_INTERFACE_VERSION,
.u.pcpu_info.xen_cpuid = 0,
};
int ret = 0;
/* Shouldn't need this as APIC is turned off for PV, and we only
* get called on the bootup processor. But just in case. */
if (!xen_initial_domain() || smp_processor_id())
return 0;
if (reg == APIC_LVR)
return 0x10;
if (reg != APIC_ID)
return 0;
ret = HYPERVISOR_dom0_op(&op);
if (ret)
return 0;
return op.u.pcpu_info.apic_id << 24;
}
static void xen_apic_write(u32 reg, u32 val)
{
/* Warn to see if there's any stray references */
WARN_ON(1);
}
static u64 xen_apic_icr_read(void)
{
return 0;
}
static void xen_apic_icr_write(u32 low, u32 id)
{
/* Warn to see if there's any stray references */
WARN_ON(1);
}
static void xen_apic_wait_icr_idle(void)
{
return;
}
static u32 xen_safe_apic_wait_icr_idle(void)
{
return 0;
}
static void set_xen_basic_apic_ops(void)
{
apic->read = xen_apic_read;
apic->write = xen_apic_write;
apic->icr_read = xen_apic_icr_read;
apic->icr_write = xen_apic_icr_write;
apic->wait_icr_idle = xen_apic_wait_icr_idle;
apic->safe_wait_icr_idle = xen_safe_apic_wait_icr_idle;
apic->set_apic_id = xen_set_apic_id;
apic->get_apic_id = xen_get_apic_id;
#ifdef CONFIG_SMP
apic->send_IPI_allbutself = xen_send_IPI_allbutself;
apic->send_IPI_mask_allbutself = xen_send_IPI_mask_allbutself;
apic->send_IPI_mask = xen_send_IPI_mask;
apic->send_IPI_all = xen_send_IPI_all;
apic->send_IPI_self = xen_send_IPI_self;
#endif
}
#endif
static void xen_clts(void)
{
struct multicall_space mcs;
mcs = xen_mc_entry(0);
MULTI_fpu_taskswitch(mcs.mc, 0);
xen_mc_issue(PARAVIRT_LAZY_CPU);
}
static DEFINE_PER_CPU(unsigned long, xen_cr0_value);
static unsigned long xen_read_cr0(void)
{
unsigned long cr0 = this_cpu_read(xen_cr0_value);
if (unlikely(cr0 == 0)) {
cr0 = native_read_cr0();
this_cpu_write(xen_cr0_value, cr0);
}
return cr0;
}
static void xen_write_cr0(unsigned long cr0)
{
struct multicall_space mcs;
this_cpu_write(xen_cr0_value, cr0);
/* Only pay attention to cr0.TS; everything else is
ignored. */
mcs = xen_mc_entry(0);
MULTI_fpu_taskswitch(mcs.mc, (cr0 & X86_CR0_TS) != 0);
xen_mc_issue(PARAVIRT_LAZY_CPU);
}
static void xen_write_cr4(unsigned long cr4)
{
cr4 &= ~X86_CR4_PGE;
cr4 &= ~X86_CR4_PSE;
native_write_cr4(cr4);
}
#ifdef CONFIG_X86_64
static inline unsigned long xen_read_cr8(void)
{
return 0;
}
static inline void xen_write_cr8(unsigned long val)
{
BUG_ON(val);
}
#endif
static int xen_write_msr_safe(unsigned int msr, unsigned low, unsigned high)
{
int ret;
ret = 0;
switch (msr) {
#ifdef CONFIG_X86_64
unsigned which;
u64 base;
case MSR_FS_BASE: which = SEGBASE_FS; goto set;
case MSR_KERNEL_GS_BASE: which = SEGBASE_GS_USER; goto set;
case MSR_GS_BASE: which = SEGBASE_GS_KERNEL; goto set;
set:
base = ((u64)high << 32) | low;
if (HYPERVISOR_set_segment_base(which, base) != 0)
ret = -EIO;
break;
#endif
case MSR_STAR:
case MSR_CSTAR:
case MSR_LSTAR:
case MSR_SYSCALL_MASK:
case MSR_IA32_SYSENTER_CS:
case MSR_IA32_SYSENTER_ESP:
case MSR_IA32_SYSENTER_EIP:
/* Fast syscall setup is all done in hypercalls, so
these are all ignored. Stub them out here to stop
Xen console noise. */
break;
case MSR_IA32_CR_PAT:
if (smp_processor_id() == 0)
xen_set_pat(((u64)high << 32) | low);
break;
default:
ret = native_write_msr_safe(msr, low, high);
}
return ret;
}
void xen_setup_shared_info(void)
{
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
set_fixmap(FIX_PARAVIRT_BOOTMAP,
xen_start_info->shared_info);
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);
#ifndef CONFIG_SMP
/* In UP this is as good a place as any to set up shared info */
xen_setup_vcpu_info_placement();
#endif
xen_setup_mfn_list_list();
}
/* This is called once we have the cpu_possible_mask */
void 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) {
pv_irq_ops.save_fl = __PV_IS_CALLEE_SAVE(xen_save_fl_direct);
pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(xen_restore_fl_direct);
pv_irq_ops.irq_disable = __PV_IS_CALLEE_SAVE(xen_irq_disable_direct);
pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct);
pv_mmu_ops.read_cr2 = xen_read_cr2_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(op, x) \
case PARAVIRT_PATCH(op.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(pv_irq_ops, irq_enable);
SITE(pv_irq_ops, irq_disable);
SITE(pv_irq_ops, save_fl);
SITE(pv_irq_ops, 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 pv_info xen_info __initconst = {
.paravirt_enabled = 1,
.shared_kernel_pmd = 0,
#ifdef CONFIG_X86_64
.extra_user_64bit_cs = FLAT_USER_CS64,
#endif
.name = "Xen",
};
static const struct pv_init_ops xen_init_ops __initconst = {
.patch = xen_patch,
};
static const struct pv_cpu_ops xen_cpu_ops __initconst = {
.cpuid = xen_cpuid,
.set_debugreg = xen_set_debugreg,
.get_debugreg = xen_get_debugreg,
.clts = xen_clts,
.read_cr0 = xen_read_cr0,
.write_cr0 = xen_write_cr0,
.read_cr4 = native_read_cr4,
.read_cr4_safe = native_read_cr4_safe,
.write_cr4 = xen_write_cr4,
#ifdef CONFIG_X86_64
.read_cr8 = xen_read_cr8,
.write_cr8 = xen_write_cr8,
#endif
.wbinvd = native_wbinvd,
.read_msr = native_read_msr_safe,
.write_msr = xen_write_msr_safe,
.read_tsc = native_read_tsc,
.read_pmc = native_read_pmc,
.read_tscp = native_read_tscp,
.iret = xen_iret,
.irq_enable_sysexit = xen_sysexit,
#ifdef CONFIG_X86_64
.usergs_sysret32 = xen_sysret32,
.usergs_sysret64 = xen_sysret64,
#endif
.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,
#ifdef CONFIG_X86_64
.load_gs_index = xen_load_gs_index,
#endif
.alloc_ldt = xen_alloc_ldt,
.free_ldt = xen_free_ldt,
.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_sp0 = xen_load_sp0,
.set_iopl_mask = xen_set_iopl_mask,
.io_delay = xen_io_delay,
/* Xen takes care of %gs when switching to usermode for us */
.swapgs = paravirt_nop,
.start_context_switch = paravirt_start_context_switch,
.end_context_switch = xen_end_context_switch,
};
static const struct pv_apic_ops xen_apic_ops __initconst = {
#ifdef CONFIG_X86_LOCAL_APIC
.startup_ipi_hook = paravirt_nop,
#endif
};
static void xen_reboot(int reason)
{
struct sched_shutdown r = { .reason = reason };
if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r))
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_machine_power_off(void)
{
if (pm_power_off)
pm_power_off();
xen_reboot(SHUTDOWN_poweroff);
}
static void xen_crash_shutdown(struct pt_regs *regs)
{
xen_reboot(SHUTDOWN_crash);
}
static int
xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr)
{
xen_reboot(SHUTDOWN_crash);
return NOTIFY_DONE;
}
static struct notifier_block xen_panic_block = {
.notifier_call= xen_panic_event,
};
int xen_panic_handler_init(void)
{
atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block);
return 0;
}
static const struct machine_ops xen_machine_ops __initconst = {
.restart = xen_restart,
.halt = xen_machine_halt,
.power_off = xen_machine_power_off,
.shutdown = xen_machine_halt,
.crash_shutdown = xen_crash_shutdown,
.emergency_restart = xen_emergency_restart,
};
/*
* Set up the GDT and segment registers for -fstack-protector. Until
* we do this, we have to be careful not to call any stack-protected
* function, which is most of the kernel.
*/
static void __init xen_setup_stackprotector(void)
{
pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry_boot;
pv_cpu_ops.load_gdt = xen_load_gdt_boot;
setup_stack_canary_segment(0);
switch_to_new_gdt(0);
pv_cpu_ops.write_gdt_entry = xen_write_gdt_entry;
pv_cpu_ops.load_gdt = xen_load_gdt;
}
/* First C function to be called on Xen boot */
asmlinkage void __init xen_start_kernel(void)
{
struct physdev_set_iopl set_iopl;
int rc;
if (!xen_start_info)
return;
xen_domain_type = XEN_PV_DOMAIN;
xen_setup_machphys_mapping();
/* Install Xen paravirt ops */
pv_info = xen_info;
pv_init_ops = xen_init_ops;
pv_cpu_ops = xen_cpu_ops;
pv_apic_ops = xen_apic_ops;
x86_init.resources.memory_setup = xen_memory_setup;
x86_init.oem.arch_setup = xen_arch_setup;
x86_init.oem.banner = xen_banner;
xen_init_time_ops();
/*
* Set up some pagetable state before starting to set any ptes.
*/
xen_init_mmu_ops();
/* Prevent unwanted bits from being set in PTEs. */
__supported_pte_mask &= ~_PAGE_GLOBAL;
#if 0
if (!xen_initial_domain())
#endif
__supported_pte_mask &= ~(_PAGE_PWT | _PAGE_PCD);
__supported_pte_mask |= _PAGE_IOMAP;
/*
* Prevent page tables from being allocated in highmem, even
* if CONFIG_HIGHPTE is enabled.
*/
__userpte_alloc_gfp &= ~__GFP_HIGHMEM;
/* Work out if we support NX */
x86_configure_nx();
xen_setup_features();
/* Get mfn list */
if (!xen_feature(XENFEAT_auto_translated_physmap))
xen_build_dynamic_phys_to_machine();
/*
* Set up kernel GDT and segment registers, mainly so that
* -fstack-protector code can be executed.
*/
xen_setup_stackprotector();
xen_init_irq_ops();
xen_init_cpuid_mask();
#ifdef CONFIG_X86_LOCAL_APIC
/*
* set up the basic apic ops.
*/
set_xen_basic_apic_ops();
#endif
if (xen_feature(XENFEAT_mmu_pt_update_preserve_ad)) {
pv_mmu_ops.ptep_modify_prot_start = xen_ptep_modify_prot_start;
pv_mmu_ops.ptep_modify_prot_commit = xen_ptep_modify_prot_commit;
}
machine_ops = xen_machine_ops;
/*
* The only reliable way to retain the initial address of the
* percpu gdt_page is to remember it here, so we can go and
* mark it RW later, when the initial percpu area is freed.
*/
xen_initial_gdt = &per_cpu(gdt_page, 0);
xen_smp_init();
#ifdef CONFIG_ACPI_NUMA
/*
* The pages we from Xen are not related to machine pages, so
* any NUMA information the kernel tries to get from ACPI will
* be meaningless. Prevent it from trying.
*/
acpi_numa = -1;
#endif
/* Don't do the full vcpu_info placement stuff until we have a
possible map and a non-dummy shared_info. */
per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
local_irq_disable();
early_boot_irqs_disabled = true;
xen_raw_console_write("mapping kernel into physical memory\n");
xen_setup_kernel_pagetable((pgd_t *)xen_start_info->pt_base, xen_start_info->nr_pages);
/* Allocate and initialize top and mid mfn levels for p2m structure */
xen_build_mfn_list_list();
/* keep using Xen gdt for now; no urgent need to change it */
#ifdef CONFIG_X86_32
pv_info.kernel_rpl = 1;
if (xen_feature(XENFEAT_supervisor_mode_kernel))
pv_info.kernel_rpl = 0;
#else
pv_info.kernel_rpl = 0;
#endif
/* set the limit of our address space */
xen_reserve_top();
/* We used to do this in xen_arch_setup, but that is too late on AMD
* were early_cpu_init (run before ->arch_setup()) calls early_amd_init
* which pokes 0xcf8 port.
*/
set_iopl.iopl = 1;
rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl);
if (rc != 0)
xen_raw_printk("physdev_op failed %d\n", rc);
#ifdef CONFIG_X86_32
/* set up basic CPUID stuff */
cpu_detect(&new_cpu_data);
new_cpu_data.hard_math = 1;
new_cpu_data.wp_works_ok = 1;
new_cpu_data.x86_capability[0] = cpuid_edx(1);
#endif
/* Poke various useful things into boot_params */
boot_params.hdr.type_of_loader = (9 << 4) | 0;
boot_params.hdr.ramdisk_image = xen_start_info->mod_start
? __pa(xen_start_info->mod_start) : 0;
boot_params.hdr.ramdisk_size = xen_start_info->mod_len;
boot_params.hdr.cmd_line_ptr = __pa(xen_start_info->cmd_line);
if (!xen_initial_domain()) {
add_preferred_console("xenboot", 0, NULL);
add_preferred_console("tty", 0, NULL);
add_preferred_console("hvc", 0, NULL);
if (pci_xen)
x86_init.pci.arch_init = pci_xen_init;
} else {
const struct dom0_vga_console_info *info =
(void *)((char *)xen_start_info +
xen_start_info->console.dom0.info_off);
struct xen_platform_op op = {
.cmd = XENPF_firmware_info,
.interface_version = XENPF_INTERFACE_VERSION,
.u.firmware_info.type = XEN_FW_KBD_SHIFT_FLAGS,
};
xen_init_vga(info, xen_start_info->console.dom0.info_size);
xen_start_info->console.domU.mfn = 0;
xen_start_info->console.domU.evtchn = 0;
if (HYPERVISOR_dom0_op(&op) == 0)
boot_params.kbd_status = op.u.firmware_info.u.kbd_shift_flags;
xen_init_apic();
/* Make sure ACS will be enabled */
pci_request_acs();
xen_acpi_sleep_register();
/* Avoid searching for BIOS MP tables */
x86_init.mpparse.find_smp_config = x86_init_noop;
x86_init.mpparse.get_smp_config = x86_init_uint_noop;
}
#ifdef CONFIG_PCI
/* PCI BIOS service won't work from a PV guest. */
pci_probe &= ~PCI_PROBE_BIOS;
#endif
xen_raw_console_write("about to get started...\n");
xen_setup_runstate_info(0);
/* Start the world */
#ifdef CONFIG_X86_32
i386_start_kernel();
#else
x86_64_start_reservations((char *)__pa_symbol(&boot_params));
#endif
}
void __ref xen_hvm_init_shared_info(void)
{
int cpu;
struct xen_add_to_physmap xatp;
static struct shared_info *shared_info_page = 0;
if (!shared_info_page)
shared_info_page = (struct shared_info *)
extend_brk(PAGE_SIZE, PAGE_SIZE);
xatp.domid = DOMID_SELF;
xatp.idx = 0;
xatp.space = XENMAPSPACE_shared_info;
xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
BUG();
HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
/* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
* page, we use it in the event channel upcall and in some pvclock
* related functions. We don't need the vcpu_info placement
* optimizations because we don't use any pv_mmu or pv_irq op on
* HVM.
* When xen_hvm_init_shared_info is run at boot time only vcpu 0 is
* online but xen_hvm_init_shared_info is run at resume time too and
* in that case multiple vcpus might be online. */
for_each_online_cpu(cpu) {
per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
}
}
#ifdef CONFIG_XEN_PVHVM
static void __init init_hvm_pv_info(void)
{
int major, minor;
uint32_t eax, ebx, ecx, edx, pages, msr, base;
u64 pfn;
base = xen_cpuid_base();
cpuid(base + 1, &eax, &ebx, &ecx, &edx);
major = eax >> 16;
minor = eax & 0xffff;
printk(KERN_INFO "Xen version %d.%d.\n", major, minor);
cpuid(base + 2, &pages, &msr, &ecx, &edx);
pfn = __pa(hypercall_page);
wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32));
xen_setup_features();
pv_info.name = "Xen HVM";
xen_domain_type = XEN_HVM_DOMAIN;
}
static int __cpuinit xen_hvm_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
int cpu = (long)hcpu;
switch (action) {
case CPU_UP_PREPARE:
xen_vcpu_setup(cpu);
if (xen_have_vector_callback)
xen_init_lock_cpu(cpu);
break;
default:
break;
}
return NOTIFY_OK;
}
static struct notifier_block xen_hvm_cpu_notifier __cpuinitdata = {
.notifier_call = xen_hvm_cpu_notify,
};
static void __init xen_hvm_guest_init(void)
{
init_hvm_pv_info();
xen_hvm_init_shared_info();
if (xen_feature(XENFEAT_hvm_callback_vector))
xen_have_vector_callback = 1;
xen_hvm_smp_init();
register_cpu_notifier(&xen_hvm_cpu_notifier);
xen_unplug_emulated_devices();
x86_init.irqs.intr_init = xen_init_IRQ;
xen_hvm_init_time_ops();
xen_hvm_init_mmu_ops();
}
static bool __init xen_hvm_platform(void)
{
if (xen_pv_domain())
return false;
if (!xen_cpuid_base())
return false;
return true;
}
bool xen_hvm_need_lapic(void)
{
if (xen_pv_domain())
return false;
if (!xen_hvm_domain())
return false;
if (xen_feature(XENFEAT_hvm_pirqs) && xen_have_vector_callback)
return false;
return true;
}
EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);
const struct hypervisor_x86 x86_hyper_xen_hvm __refconst = {
.name = "Xen HVM",
.detect = xen_hvm_platform,
.init_platform = xen_hvm_guest_init,
};
EXPORT_SYMBOL(x86_hyper_xen_hvm);
#endif
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