[deliverable/linux.git] / arch / x86 / kernel / paravirt.c

/*  Paravirtualization interfaces
    Copyright (C) 2006 Rusty Russell IBM Corporation

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    2007 - x86_64 support added by Glauber de Oliveira Costa, Red Hat Inc
*/

#include <linux/errno.h>
#include <linux/module.h>
#include <linux/efi.h>
#include <linux/bcd.h>
#include <linux/highmem.h>
#include <linux/kprobes.h>

#include <asm/bug.h>
#include <asm/paravirt.h>
#include <asm/debugreg.h>
#include <asm/desc.h>
#include <asm/setup.h>
#include <asm/pgtable.h>
#include <asm/time.h>
#include <asm/pgalloc.h>
#include <asm/irq.h>
#include <asm/delay.h>
#include <asm/fixmap.h>
#include <asm/apic.h>
#include <asm/tlbflush.h>
#include <asm/timer.h>
#include <asm/special_insns.h>

/* nop stub */
void _paravirt_nop(void)
{
}

/* identity function, which can be inlined */
u32 _paravirt_ident_32(u32 x)
{
	return x;
}

u64 _paravirt_ident_64(u64 x)
{
	return x;
}

void __init default_banner(void)
{
	printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
	       pv_info.name);
}

/* Undefined instruction for dealing with missing ops pointers. */
static const unsigned char ud2a[] = { 0x0f, 0x0b };

unsigned paravirt_patch_nop(void)
{
	return 0;
}

unsigned paravirt_patch_ignore(unsigned len)
{
	return len;
}

struct branch {
	unsigned char opcode;
	u32 delta;
} __attribute__((packed));

unsigned paravirt_patch_call(void *insnbuf,
			     const void *target, u16 tgt_clobbers,
			     unsigned long addr, u16 site_clobbers,
			     unsigned len)
{
	struct branch *b = insnbuf;
	unsigned long delta = (unsigned long)target - (addr+5);

	if (tgt_clobbers & ~site_clobbers)
		return len;	/* target would clobber too much for this site */
	if (len < 5)
		return len;	/* call too long for patch site */

	b->opcode = 0xe8; /* call */
	b->delta = delta;
	BUILD_BUG_ON(sizeof(*b) != 5);

	return 5;
}

unsigned paravirt_patch_jmp(void *insnbuf, const void *target,
			    unsigned long addr, unsigned len)
{
	struct branch *b = insnbuf;
	unsigned long delta = (unsigned long)target - (addr+5);

	if (len < 5)
		return len;	/* call too long for patch site */

	b->opcode = 0xe9;	/* jmp */
	b->delta = delta;

	return 5;
}

/* Neat trick to map patch type back to the call within the
 * corresponding structure. */
static void *get_call_destination(u8 type)
{
	struct paravirt_patch_template tmpl = {
		.pv_init_ops = pv_init_ops,
		.pv_time_ops = pv_time_ops,
		.pv_cpu_ops = pv_cpu_ops,
		.pv_irq_ops = pv_irq_ops,
		.pv_apic_ops = pv_apic_ops,
		.pv_mmu_ops = pv_mmu_ops,
#ifdef CONFIG_PARAVIRT_SPINLOCKS
		.pv_lock_ops = pv_lock_ops,
#endif
	};
	return *((void **)&tmpl + type);
}

unsigned paravirt_patch_default(u8 type, u16 clobbers, void *insnbuf,
				unsigned long addr, unsigned len)
{
	void *opfunc = get_call_destination(type);
	unsigned ret;

	if (opfunc == NULL)
		/* If there's no function, patch it with a ud2a (BUG) */
		ret = paravirt_patch_insns(insnbuf, len, ud2a, ud2a+sizeof(ud2a));
	else if (opfunc == _paravirt_nop)
		/* If the operation is a nop, then nop the callsite */
		ret = paravirt_patch_nop();

	/* identity functions just return their single argument */
	else if (opfunc == _paravirt_ident_32)
		ret = paravirt_patch_ident_32(insnbuf, len);
	else if (opfunc == _paravirt_ident_64)
		ret = paravirt_patch_ident_64(insnbuf, len);

	else if (type == PARAVIRT_PATCH(pv_cpu_ops.iret) ||
#ifdef CONFIG_X86_32
		 type == PARAVIRT_PATCH(pv_cpu_ops.irq_enable_sysexit) ||
#endif
		 type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret32) ||
		 type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret64))
		/* If operation requires a jmp, then jmp */
		ret = paravirt_patch_jmp(insnbuf, opfunc, addr, len);
	else
		/* Otherwise call the function; assume target could
		   clobber any caller-save reg */
		ret = paravirt_patch_call(insnbuf, opfunc, CLBR_ANY,
					  addr, clobbers, len);

	return ret;
}

unsigned paravirt_patch_insns(void *insnbuf, unsigned len,
			      const char *start, const char *end)
{
	unsigned insn_len = end - start;

	if (insn_len > len || start == NULL)
		insn_len = len;
	else
		memcpy(insnbuf, start, insn_len);

	return insn_len;
}

static void native_flush_tlb(void)
{
	__native_flush_tlb();
}

/*
 * Global pages have to be flushed a bit differently. Not a real
 * performance problem because this does not happen often.
 */
static void native_flush_tlb_global(void)
{
	__native_flush_tlb_global();
}

static void native_flush_tlb_single(unsigned long addr)
{
	__native_flush_tlb_single(addr);
}

struct static_key paravirt_steal_enabled;
struct static_key paravirt_steal_rq_enabled;

static u64 native_steal_clock(int cpu)
{
	return 0;
}

/* These are in entry.S */
extern void native_iret(void);
extern void native_irq_enable_sysexit(void);
extern void native_usergs_sysret32(void);
extern void native_usergs_sysret64(void);

static struct resource reserve_ioports = {
	.start = 0,
	.end = IO_SPACE_LIMIT,
	.name = "paravirt-ioport",
	.flags = IORESOURCE_IO | IORESOURCE_BUSY,
};

/*
 * Reserve the whole legacy IO space to prevent any legacy drivers
 * from wasting time probing for their hardware.  This is a fairly
 * brute-force approach to disabling all non-virtual drivers.
 *
 * Note that this must be called very early to have any effect.
 */
int paravirt_disable_iospace(void)
{
	return request_resource(&ioport_resource, &reserve_ioports);
}

static DEFINE_PER_CPU(enum paravirt_lazy_mode, paravirt_lazy_mode) = PARAVIRT_LAZY_NONE;

static inline void enter_lazy(enum paravirt_lazy_mode mode)
{
	BUG_ON(this_cpu_read(paravirt_lazy_mode) != PARAVIRT_LAZY_NONE);

	this_cpu_write(paravirt_lazy_mode, mode);
}

static void leave_lazy(enum paravirt_lazy_mode mode)
{
	BUG_ON(this_cpu_read(paravirt_lazy_mode) != mode);

	this_cpu_write(paravirt_lazy_mode, PARAVIRT_LAZY_NONE);
}

void paravirt_enter_lazy_mmu(void)
{
	enter_lazy(PARAVIRT_LAZY_MMU);
}

void paravirt_leave_lazy_mmu(void)
{
	leave_lazy(PARAVIRT_LAZY_MMU);
}

void paravirt_flush_lazy_mmu(void)
{
	preempt_disable();

	if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) {
		arch_leave_lazy_mmu_mode();
		arch_enter_lazy_mmu_mode();
	}

	preempt_enable();
}

void paravirt_start_context_switch(struct task_struct *prev)
{
	BUG_ON(preemptible());

	if (this_cpu_read(paravirt_lazy_mode) == PARAVIRT_LAZY_MMU) {
		arch_leave_lazy_mmu_mode();
		set_ti_thread_flag(task_thread_info(prev), TIF_LAZY_MMU_UPDATES);
	}
	enter_lazy(PARAVIRT_LAZY_CPU);
}

void paravirt_end_context_switch(struct task_struct *next)
{
	BUG_ON(preemptible());

	leave_lazy(PARAVIRT_LAZY_CPU);

	if (test_and_clear_ti_thread_flag(task_thread_info(next), TIF_LAZY_MMU_UPDATES))
		arch_enter_lazy_mmu_mode();
}

enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
{
	if (in_interrupt())
		return PARAVIRT_LAZY_NONE;

	return this_cpu_read(paravirt_lazy_mode);
}

struct pv_info pv_info = {
	.name = "bare hardware",
	.paravirt_enabled = 0,
	.kernel_rpl = 0,
	.shared_kernel_pmd = 1,	/* Only used when CONFIG_X86_PAE is set */

#ifdef CONFIG_X86_64
	.extra_user_64bit_cs = __USER_CS,
#endif
};

struct pv_init_ops pv_init_ops = {
	.patch = native_patch,
};

struct pv_time_ops pv_time_ops = {
	.sched_clock = native_sched_clock,
	.steal_clock = native_steal_clock,
};

__visible struct pv_irq_ops pv_irq_ops = {
	.save_fl = __PV_IS_CALLEE_SAVE(native_save_fl),
	.restore_fl = __PV_IS_CALLEE_SAVE(native_restore_fl),
	.irq_disable = __PV_IS_CALLEE_SAVE(native_irq_disable),
	.irq_enable = __PV_IS_CALLEE_SAVE(native_irq_enable),
	.safe_halt = native_safe_halt,
	.halt = native_halt,
#ifdef CONFIG_X86_64
	.adjust_exception_frame = paravirt_nop,
#endif
};

__visible struct pv_cpu_ops pv_cpu_ops = {
	.cpuid = native_cpuid,
	.get_debugreg = native_get_debugreg,
	.set_debugreg = native_set_debugreg,
	.clts = native_clts,
	.read_cr0 = native_read_cr0,
	.write_cr0 = native_write_cr0,
	.read_cr4 = native_read_cr4,
	.read_cr4_safe = native_read_cr4_safe,
	.write_cr4 = native_write_cr4,
#ifdef CONFIG_X86_64
	.read_cr8 = native_read_cr8,
	.write_cr8 = native_write_cr8,
#endif
	.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,
	.read_tscp = native_read_tscp,
	.load_tr_desc = native_load_tr_desc,
	.set_ldt = native_set_ldt,
	.load_gdt = native_load_gdt,
	.load_idt = native_load_idt,
	.store_idt = native_store_idt,
	.store_tr = native_store_tr,
	.load_tls = native_load_tls,
#ifdef CONFIG_X86_64
	.load_gs_index = native_load_gs_index,
#endif
	.write_ldt_entry = native_write_ldt_entry,
	.write_gdt_entry = native_write_gdt_entry,
	.write_idt_entry = native_write_idt_entry,

	.alloc_ldt = paravirt_nop,
	.free_ldt = paravirt_nop,

	.load_sp0 = native_load_sp0,

#if defined(CONFIG_X86_32)
	.irq_enable_sysexit = native_irq_enable_sysexit,
#endif
#ifdef CONFIG_X86_64
#ifdef CONFIG_IA32_EMULATION
	.usergs_sysret32 = native_usergs_sysret32,
#endif
	.usergs_sysret64 = native_usergs_sysret64,
#endif
	.iret = native_iret,
	.swapgs = native_swapgs,

	.set_iopl_mask = native_set_iopl_mask,
	.io_delay = native_io_delay,

	.start_context_switch = paravirt_nop,
	.end_context_switch = paravirt_nop,
};

/* At this point, native_get/set_debugreg has real function entries */
NOKPROBE_SYMBOL(native_get_debugreg);
NOKPROBE_SYMBOL(native_set_debugreg);
NOKPROBE_SYMBOL(native_load_idt);

struct pv_apic_ops pv_apic_ops = {
#ifdef CONFIG_X86_LOCAL_APIC
	.startup_ipi_hook = paravirt_nop,
#endif
};

#if defined(CONFIG_X86_32) && !defined(CONFIG_X86_PAE)
/* 32-bit pagetable entries */
#define PTE_IDENT	__PV_IS_CALLEE_SAVE(_paravirt_ident_32)
#else
/* 64-bit pagetable entries */
#define PTE_IDENT	__PV_IS_CALLEE_SAVE(_paravirt_ident_64)
#endif

struct pv_mmu_ops pv_mmu_ops = {

	.read_cr2 = native_read_cr2,
	.write_cr2 = native_write_cr2,
	.read_cr3 = native_read_cr3,
	.write_cr3 = native_write_cr3,

	.flush_tlb_user = native_flush_tlb,
	.flush_tlb_kernel = native_flush_tlb_global,
	.flush_tlb_single = native_flush_tlb_single,
	.flush_tlb_others = native_flush_tlb_others,

	.pgd_alloc = __paravirt_pgd_alloc,
	.pgd_free = paravirt_nop,

	.alloc_pte = paravirt_nop,
	.alloc_pmd = paravirt_nop,
	.alloc_pud = paravirt_nop,
	.release_pte = paravirt_nop,
	.release_pmd = paravirt_nop,
	.release_pud = paravirt_nop,

	.set_pte = native_set_pte,
	.set_pte_at = native_set_pte_at,
	.set_pmd = native_set_pmd,
	.set_pmd_at = native_set_pmd_at,
	.pte_update = paravirt_nop,
	.pte_update_defer = paravirt_nop,
	.pmd_update = paravirt_nop,
	.pmd_update_defer = paravirt_nop,

	.ptep_modify_prot_start = __ptep_modify_prot_start,
	.ptep_modify_prot_commit = __ptep_modify_prot_commit,

#if CONFIG_PGTABLE_LEVELS >= 3
#ifdef CONFIG_X86_PAE
	.set_pte_atomic = native_set_pte_atomic,
	.pte_clear = native_pte_clear,
	.pmd_clear = native_pmd_clear,
#endif
	.set_pud = native_set_pud,

	.pmd_val = PTE_IDENT,
	.make_pmd = PTE_IDENT,

#if CONFIG_PGTABLE_LEVELS == 4
	.pud_val = PTE_IDENT,
	.make_pud = PTE_IDENT,

	.set_pgd = native_set_pgd,
#endif
#endif /* CONFIG_PGTABLE_LEVELS >= 3 */

	.pte_val = PTE_IDENT,
	.pgd_val = PTE_IDENT,

	.make_pte = PTE_IDENT,
	.make_pgd = PTE_IDENT,

	.dup_mmap = paravirt_nop,
	.exit_mmap = paravirt_nop,
	.activate_mm = paravirt_nop,

	.lazy_mode = {
		.enter = paravirt_nop,
		.leave = paravirt_nop,
		.flush = paravirt_nop,
	},

	.set_fixmap = native_set_fixmap,
};

EXPORT_SYMBOL_GPL(pv_time_ops);
EXPORT_SYMBOL    (pv_cpu_ops);
EXPORT_SYMBOL    (pv_mmu_ops);
EXPORT_SYMBOL_GPL(pv_apic_ops);
EXPORT_SYMBOL_GPL(pv_info);
EXPORT_SYMBOL    (pv_irq_ops);
Commit	Line	Data
	1	/* Paravirtualization interfaces
	2	Copyright (C) 2006 Rusty Russell IBM Corporation
	3
	4	This program is free software; you can redistribute it and/or modify
	5	it under the terms of the GNU General Public License as published by
	6	the Free Software Foundation; either version 2 of the License, or
	7	(at your option) any later version.
	8
	9	This program is distributed in the hope that it will be useful,
	10	but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	GNU General Public License for more details.
	13
	14	You should have received a copy of the GNU General Public License
	15	along with this program; if not, write to the Free Software
	16	Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	17
	18	2007 - x86_64 support added by Glauber de Oliveira Costa, Red Hat Inc
	19	*/
	20
	21	#include <linux/errno.h>
	22	#include <linux/module.h>
	23	#include <linux/efi.h>
	24	#include <linux/bcd.h>
	25	#include <linux/highmem.h>
	26	#include <linux/kprobes.h>
	27
	28	#include <asm/bug.h>
	29	#include <asm/paravirt.h>
	30	#include <asm/debugreg.h>
	31	#include <asm/desc.h>
	32	#include <asm/setup.h>
	33	#include <asm/pgtable.h>
	34	#include <asm/time.h>
	35	#include <asm/pgalloc.h>
	36	#include <asm/irq.h>
	37	#include <asm/delay.h>
	38	#include <asm/fixmap.h>
	39	#include <asm/apic.h>
	40	#include <asm/tlbflush.h>
	41	#include <asm/timer.h>
	42	#include <asm/special_insns.h>
	43
	44	/* nop stub */
	45	void _paravirt_nop(void)
	46	{
	47	}
	48
	49	/* identity function, which can be inlined */
	50	u32 _paravirt_ident_32(u32 x)
	51	{
	52	return x;
	53	}
	54
	55	u64 _paravirt_ident_64(u64 x)
	56	{
	57	return x;
	58	}
	59
	60	void __init default_banner(void)
	61	{
	62	printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
	63	pv_info.name);
	64	}
	65
	66	/* Undefined instruction for dealing with missing ops pointers. */
	67	static const unsigned char ud2a[] = { 0x0f, 0x0b };
	68
	69	unsigned paravirt_patch_nop(void)
	70	{
	71	return 0;
	72	}
	73
	74	unsigned paravirt_patch_ignore(unsigned len)
	75	{
	76	return len;
	77	}
	78
	79	struct branch {
	80	unsigned char opcode;
	81	u32 delta;
	82	} __attribute__((packed));
	83
	84	unsigned paravirt_patch_call(void *insnbuf,
	85	const void *target, u16 tgt_clobbers,
	86	unsigned long addr, u16 site_clobbers,
	87	unsigned len)
	88	{
	89	struct branch *b = insnbuf;
	90	unsigned long delta = (unsigned long)target - (addr+5);
	91
	92	if (tgt_clobbers & ~site_clobbers)
	93	return len; /* target would clobber too much for this site */
	94	if (len < 5)
	95	return len; /* call too long for patch site */
	96
	97	b->opcode = 0xe8; /* call */
	98	b->delta = delta;
	99	BUILD_BUG_ON(sizeof(*b) != 5);
	100
	101	return 5;
	102	}
	103
	104	unsigned paravirt_patch_jmp(void insnbuf, const void target,
	105	unsigned long addr, unsigned len)
	106	{
	107	struct branch *b = insnbuf;
	108	unsigned long delta = (unsigned long)target - (addr+5);
	109
	110	if (len < 5)
	111	return len; /* call too long for patch site */
	112
	113	b->opcode = 0xe9; /* jmp */
	114	b->delta = delta;
	115
	116	return 5;
	117	}
	118
	119	/* Neat trick to map patch type back to the call within the
	120	* corresponding structure. */
	121	static void *get_call_destination(u8 type)
	122	{
	123	struct paravirt_patch_template tmpl = {
	124	.pv_init_ops = pv_init_ops,
	125	.pv_time_ops = pv_time_ops,
	126	.pv_cpu_ops = pv_cpu_ops,
	127	.pv_irq_ops = pv_irq_ops,
	128	.pv_apic_ops = pv_apic_ops,
	129	.pv_mmu_ops = pv_mmu_ops,
	130	#ifdef CONFIG_PARAVIRT_SPINLOCKS
	131	.pv_lock_ops = pv_lock_ops,
	132	#endif
	133	};
	134	return ((void *)&tmpl + type);
	135	}
	136
	137	unsigned paravirt_patch_default(u8 type, u16 clobbers, void *insnbuf,
	138	unsigned long addr, unsigned len)
	139	{
	140	void *opfunc = get_call_destination(type);
	141	unsigned ret;
	142
	143	if (opfunc == NULL)
	144	/* If there's no function, patch it with a ud2a (BUG) */
	145	ret = paravirt_patch_insns(insnbuf, len, ud2a, ud2a+sizeof(ud2a));
	146	else if (opfunc == _paravirt_nop)
	147	/* If the operation is a nop, then nop the callsite */
	148	ret = paravirt_patch_nop();
	149
	150	/* identity functions just return their single argument */
	151	else if (opfunc == _paravirt_ident_32)
	152	ret = paravirt_patch_ident_32(insnbuf, len);
	153	else if (opfunc == _paravirt_ident_64)
	154	ret = paravirt_patch_ident_64(insnbuf, len);
	155
	156	else if (type == PARAVIRT_PATCH(pv_cpu_ops.iret) \|\|
	157	#ifdef CONFIG_X86_32
	158	type == PARAVIRT_PATCH(pv_cpu_ops.irq_enable_sysexit) \|\|
	159	#endif
	160	type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret32) \|\|
	161	type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret64))
	162	/* If operation requires a jmp, then jmp */
	163	ret = paravirt_patch_jmp(insnbuf, opfunc, addr, len);
	164	else
	165	/* Otherwise call the function; assume target could
	166	clobber any caller-save reg */
	167	ret = paravirt_patch_call(insnbuf, opfunc, CLBR_ANY,
	168	addr, clobbers, len);
	169
	170	return ret;
	171	}
	172
	173	unsigned paravirt_patch_insns(void *insnbuf, unsigned len,
	174	const char start, const char end)
	175	{
	176	unsigned insn_len = end - start;
	177
	178	if (insn_len > len \|\| start == NULL)
	179	insn_len = len;
	180	else
	181	memcpy(insnbuf, start, insn_len);
	182
	183	return insn_len;
	184	}
	185
	186	static void native_flush_tlb(void)
	187	{
	188	__native_flush_tlb();
	189	}
	190
	191	/*
	192	* Global pages have to be flushed a bit differently. Not a real
	193	* performance problem because this does not happen often.
	194	*/
	195	static void native_flush_tlb_global(void)
	196	{
	197	__native_flush_tlb_global();
	198	}
	199
	200	static void native_flush_tlb_single(unsigned long addr)
	201	{
	202	__native_flush_tlb_single(addr);
	203	}
	204
	205	struct static_key paravirt_steal_enabled;
	206	struct static_key paravirt_steal_rq_enabled;
	207
	208	static u64 native_steal_clock(int cpu)
	209	{
	210	return 0;
	211	}
	212
	213	/* These are in entry.S */
	214	extern void native_iret(void);
	215	extern void native_irq_enable_sysexit(void);
	216	extern void native_usergs_sysret32(void);
	217	extern void native_usergs_sysret64(void);
	218
	219	static struct resource reserve_ioports = {
	220	.start = 0,
	221	.end = IO_SPACE_LIMIT,
	222	.name = "paravirt-ioport",
	223	.flags = IORESOURCE_IO \| IORESOURCE_BUSY,
	224	};
	225
	226	/*
	227	* Reserve the whole legacy IO space to prevent any legacy drivers
	228	* from wasting time probing for their hardware. This is a fairly
	229	* brute-force approach to disabling all non-virtual drivers.
	230	*
	231	* Note that this must be called very early to have any effect.
	232	*/
	233	int paravirt_disable_iospace(void)
	234	{
	235	return request_resource(&ioport_resource, &reserve_ioports);
	236	}
	237
	238	static DEFINE_PER_CPU(enum paravirt_lazy_mode, paravirt_lazy_mode) = PARAVIRT_LAZY_NONE;
	239
	240	static inline void enter_lazy(enum paravirt_lazy_mode mode)
	241	{
	242	BUG_ON(this_cpu_read(paravirt_lazy_mode) != PARAVIRT_LAZY_NONE);
	243
	244	this_cpu_write(paravirt_lazy_mode, mode);
	245	}
	246
	247	static void leave_lazy(enum paravirt_lazy_mode mode)
	248	{
	249	BUG_ON(this_cpu_read(paravirt_lazy_mode) != mode);
	250
	251	this_cpu_write(paravirt_lazy_mode, PARAVIRT_LAZY_NONE);
	252	}
	253
	254	void paravirt_enter_lazy_mmu(void)
	255	{
	256	enter_lazy(PARAVIRT_LAZY_MMU);
	257	}
	258
	259	void paravirt_leave_lazy_mmu(void)
	260	{
	261	leave_lazy(PARAVIRT_LAZY_MMU);
	262	}
	263
	264	void paravirt_flush_lazy_mmu(void)
	265	{
	266	preempt_disable();
	267
	268	if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) {
	269	arch_leave_lazy_mmu_mode();
	270	arch_enter_lazy_mmu_mode();
	271	}
	272
	273	preempt_enable();
	274	}
	275
	276	void paravirt_start_context_switch(struct task_struct *prev)
	277	{
	278	BUG_ON(preemptible());
	279
	280	if (this_cpu_read(paravirt_lazy_mode) == PARAVIRT_LAZY_MMU) {
	281	arch_leave_lazy_mmu_mode();
	282	set_ti_thread_flag(task_thread_info(prev), TIF_LAZY_MMU_UPDATES);
	283	}
	284	enter_lazy(PARAVIRT_LAZY_CPU);
	285	}
	286
	287	void paravirt_end_context_switch(struct task_struct *next)
	288	{
	289	BUG_ON(preemptible());
	290
	291	leave_lazy(PARAVIRT_LAZY_CPU);
	292
	293	if (test_and_clear_ti_thread_flag(task_thread_info(next), TIF_LAZY_MMU_UPDATES))
	294	arch_enter_lazy_mmu_mode();
	295	}
	296
	297	enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
	298	{
	299	if (in_interrupt())
	300	return PARAVIRT_LAZY_NONE;
	301
	302	return this_cpu_read(paravirt_lazy_mode);
	303	}
	304
	305	struct pv_info pv_info = {
	306	.name = "bare hardware",
	307	.paravirt_enabled = 0,
	308	.kernel_rpl = 0,
	309	.shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */
	310
	311	#ifdef CONFIG_X86_64
	312	.extra_user_64bit_cs = __USER_CS,
	313	#endif
	314	};
	315
	316	struct pv_init_ops pv_init_ops = {
	317	.patch = native_patch,
	318	};
	319
	320	struct pv_time_ops pv_time_ops = {
	321	.sched_clock = native_sched_clock,
	322	.steal_clock = native_steal_clock,
	323	};
	324
	325	__visible struct pv_irq_ops pv_irq_ops = {
	326	.save_fl = __PV_IS_CALLEE_SAVE(native_save_fl),
	327	.restore_fl = __PV_IS_CALLEE_SAVE(native_restore_fl),
	328	.irq_disable = __PV_IS_CALLEE_SAVE(native_irq_disable),
	329	.irq_enable = __PV_IS_CALLEE_SAVE(native_irq_enable),
	330	.safe_halt = native_safe_halt,
	331	.halt = native_halt,
	332	#ifdef CONFIG_X86_64
	333	.adjust_exception_frame = paravirt_nop,
	334	#endif
	335	};
	336
	337	__visible struct pv_cpu_ops pv_cpu_ops = {
	338	.cpuid = native_cpuid,
	339	.get_debugreg = native_get_debugreg,
	340	.set_debugreg = native_set_debugreg,
	341	.clts = native_clts,
	342	.read_cr0 = native_read_cr0,
	343	.write_cr0 = native_write_cr0,
	344	.read_cr4 = native_read_cr4,
	345	.read_cr4_safe = native_read_cr4_safe,
	346	.write_cr4 = native_write_cr4,
	347	#ifdef CONFIG_X86_64
	348	.read_cr8 = native_read_cr8,
	349	.write_cr8 = native_write_cr8,
	350	#endif
	351	.wbinvd = native_wbinvd,
	352	.read_msr = native_read_msr_safe,
	353	.write_msr = native_write_msr_safe,
	354	.read_tsc = native_read_tsc,
	355	.read_pmc = native_read_pmc,
	356	.read_tscp = native_read_tscp,
	357	.load_tr_desc = native_load_tr_desc,
	358	.set_ldt = native_set_ldt,
	359	.load_gdt = native_load_gdt,
	360	.load_idt = native_load_idt,
	361	.store_idt = native_store_idt,
	362	.store_tr = native_store_tr,
	363	.load_tls = native_load_tls,
	364	#ifdef CONFIG_X86_64
	365	.load_gs_index = native_load_gs_index,
	366	#endif
	367	.write_ldt_entry = native_write_ldt_entry,
	368	.write_gdt_entry = native_write_gdt_entry,
	369	.write_idt_entry = native_write_idt_entry,
	370
	371	.alloc_ldt = paravirt_nop,
	372	.free_ldt = paravirt_nop,
	373
	374	.load_sp0 = native_load_sp0,
	375
	376	#if defined(CONFIG_X86_32)
	377	.irq_enable_sysexit = native_irq_enable_sysexit,
	378	#endif
	379	#ifdef CONFIG_X86_64
	380	#ifdef CONFIG_IA32_EMULATION
	381	.usergs_sysret32 = native_usergs_sysret32,
	382	#endif
	383	.usergs_sysret64 = native_usergs_sysret64,
	384	#endif
	385	.iret = native_iret,
	386	.swapgs = native_swapgs,
	387
	388	.set_iopl_mask = native_set_iopl_mask,
	389	.io_delay = native_io_delay,
	390
	391	.start_context_switch = paravirt_nop,
	392	.end_context_switch = paravirt_nop,
	393	};
	394
	395	/* At this point, native_get/set_debugreg has real function entries */
	396	NOKPROBE_SYMBOL(native_get_debugreg);
	397	NOKPROBE_SYMBOL(native_set_debugreg);
	398	NOKPROBE_SYMBOL(native_load_idt);
	399
	400	struct pv_apic_ops pv_apic_ops = {
	401	#ifdef CONFIG_X86_LOCAL_APIC
	402	.startup_ipi_hook = paravirt_nop,
	403	#endif
	404	};
	405
	406	#if defined(CONFIG_X86_32) && !defined(CONFIG_X86_PAE)
	407	/* 32-bit pagetable entries */
	408	#define PTE_IDENT __PV_IS_CALLEE_SAVE(_paravirt_ident_32)
	409	#else
	410	/* 64-bit pagetable entries */
	411	#define PTE_IDENT __PV_IS_CALLEE_SAVE(_paravirt_ident_64)
	412	#endif
	413
	414	struct pv_mmu_ops pv_mmu_ops = {
	415
	416	.read_cr2 = native_read_cr2,
	417	.write_cr2 = native_write_cr2,
	418	.read_cr3 = native_read_cr3,
	419	.write_cr3 = native_write_cr3,
	420
	421	.flush_tlb_user = native_flush_tlb,
	422	.flush_tlb_kernel = native_flush_tlb_global,
	423	.flush_tlb_single = native_flush_tlb_single,
	424	.flush_tlb_others = native_flush_tlb_others,
	425
	426	.pgd_alloc = __paravirt_pgd_alloc,
	427	.pgd_free = paravirt_nop,
	428
	429	.alloc_pte = paravirt_nop,
	430	.alloc_pmd = paravirt_nop,
	431	.alloc_pud = paravirt_nop,
	432	.release_pte = paravirt_nop,
	433	.release_pmd = paravirt_nop,
	434	.release_pud = paravirt_nop,
	435
	436	.set_pte = native_set_pte,
	437	.set_pte_at = native_set_pte_at,
	438	.set_pmd = native_set_pmd,
	439	.set_pmd_at = native_set_pmd_at,
	440	.pte_update = paravirt_nop,
	441	.pte_update_defer = paravirt_nop,
	442	.pmd_update = paravirt_nop,
	443	.pmd_update_defer = paravirt_nop,
	444
	445	.ptep_modify_prot_start = __ptep_modify_prot_start,
	446	.ptep_modify_prot_commit = __ptep_modify_prot_commit,
	447
	448	#if CONFIG_PGTABLE_LEVELS >= 3
	449	#ifdef CONFIG_X86_PAE
	450	.set_pte_atomic = native_set_pte_atomic,
	451	.pte_clear = native_pte_clear,
	452	.pmd_clear = native_pmd_clear,
	453	#endif
	454	.set_pud = native_set_pud,
	455
	456	.pmd_val = PTE_IDENT,
	457	.make_pmd = PTE_IDENT,
	458
	459	#if CONFIG_PGTABLE_LEVELS == 4
	460	.pud_val = PTE_IDENT,
	461	.make_pud = PTE_IDENT,
	462
	463	.set_pgd = native_set_pgd,
	464	#endif
	465	#endif /* CONFIG_PGTABLE_LEVELS >= 3 */
	466
	467	.pte_val = PTE_IDENT,
	468	.pgd_val = PTE_IDENT,
	469
	470	.make_pte = PTE_IDENT,
	471	.make_pgd = PTE_IDENT,
	472
	473	.dup_mmap = paravirt_nop,
	474	.exit_mmap = paravirt_nop,
	475	.activate_mm = paravirt_nop,
	476
	477	.lazy_mode = {
	478	.enter = paravirt_nop,
	479	.leave = paravirt_nop,
	480	.flush = paravirt_nop,
	481	},
	482
	483	.set_fixmap = native_set_fixmap,
	484	};
	485
	486	EXPORT_SYMBOL_GPL(pv_time_ops);
	487	EXPORT_SYMBOL (pv_cpu_ops);
	488	EXPORT_SYMBOL (pv_mmu_ops);
	489	EXPORT_SYMBOL_GPL(pv_apic_ops);
	490	EXPORT_SYMBOL_GPL(pv_info);
	491	EXPORT_SYMBOL (pv_irq_ops);