paravirt.h

#ifndef _ASM_X86_PARAVIRT_H
#define _ASM_X86_PARAVIRT_H
/* Various instructions on x86 need to be replaced for
 * para-virtualization: those hooks are defined here. */

#ifdef CONFIG_PARAVIRT
#include <asm/page.h>
#include <asm/asm.h>

/* Bitmask of what can be clobbered: usually at least eax. */
#define CLBR_NONE 0
#define CLBR_EAX  (1 << 0)
#define CLBR_ECX  (1 << 1)
#define CLBR_EDX  (1 << 2)
#define CLBR_EDI  (1 << 3)

#ifdef CONFIG_X86_32
/* CLBR_ANY should match all regs platform has. For i386, that's just it */
#define CLBR_ANY  ((1 << 4) - 1)
#else
#define CLBR_RAX  CLBR_EAX
#define CLBR_RCX  CLBR_ECX
#define CLBR_RDX  CLBR_EDX
#define CLBR_RDI  CLBR_EDI
#define CLBR_RSI  (1 << 4)
#define CLBR_R8   (1 << 5)
#define CLBR_R9   (1 << 6)
#define CLBR_R10  (1 << 7)
#define CLBR_R11  (1 << 8)
#define CLBR_ANY  ((1 << 9) - 1)

#define CLBR_ARG_REGS	(CLBR_RDI | CLBR_RSI | CLBR_RDX | \
			 CLBR_RCX | CLBR_R8 | CLBR_R9)
#define CLBR_RET_REG	(CLBR_RAX | CLBR_RDX)
#define CLBR_SCRATCH	(CLBR_R10 | CLBR_R11)

#include <asm/desc_defs.h>
#endif /* X86_64 */

#ifndef __ASSEMBLY__
#include <linux/types.h>
#include <linux/cpumask.h>
#include <asm/kmap_types.h>
#include <asm/desc_defs.h>

struct page;
struct thread_struct;
struct desc_ptr;
struct tss_struct;
struct mm_struct;
struct desc_struct;

/* general info */
struct pv_info {
	unsigned int kernel_rpl;
	int shared_kernel_pmd;
	int paravirt_enabled;
	const char *name;
};

struct pv_init_ops {
	/*
	 * Patch may replace one of the defined code sequences with
	 * arbitrary code, subject to the same register constraints.
	 * This generally means the code is not free to clobber any
	 * registers other than EAX.  The patch function should return
	 * the number of bytes of code generated, as we nop pad the
	 * rest in generic code.
	 */
	unsigned (*patch)(u8 type, u16 clobber, void *insnbuf,
			  unsigned long addr, unsigned len);

	/* Basic arch-specific setup */
	void (*arch_setup)(void);
	char *(*memory_setup)(void);
	void (*post_allocator_init)(void);

	/* Print a banner to identify the environment */
	void (*banner)(void);
};


struct pv_lazy_ops {
	/* Set deferred update mode, used for batching operations. */
	void (*enter)(void);
	void (*leave)(void);
};

struct pv_time_ops {
	void (*time_init)(void);

	/* Set and set time of day */
	unsigned long (*get_wallclock)(void);
	int (*set_wallclock)(unsigned long);

	unsigned long long (*sched_clock)(void);
	unsigned long (*get_tsc_khz)(void);
};

struct pv_cpu_ops {
	/* hooks for various privileged instructions */
	unsigned long (*get_debugreg)(int regno);
	void (*set_debugreg)(int regno, unsigned long value);

	void (*clts)(void);

	unsigned long (*read_cr0)(void);
	void (*write_cr0)(unsigned long);

	unsigned long (*read_cr4_safe)(void);
	unsigned long (*read_cr4)(void);
	void (*write_cr4)(unsigned long);

#ifdef CONFIG_X86_64
	unsigned long (*read_cr8)(void);
	void (*write_cr8)(unsigned long);
#endif

	/* Segment descriptor handling */
	void (*load_tr_desc)(void);
	void (*load_gdt)(const struct desc_ptr *);
	void (*load_idt)(const struct desc_ptr *);
	void (*store_gdt)(struct desc_ptr *);
	void (*store_idt)(struct desc_ptr *);
	void (*set_ldt)(const void *desc, unsigned entries);
	unsigned long (*store_tr)(void);
	void (*load_tls)(struct thread_struct *t, unsigned int cpu);
#ifdef CONFIG_X86_64
	void (*load_gs_index)(unsigned int idx);
#endif
	void (*write_ldt_entry)(struct desc_struct *ldt, int entrynum,
				const void *desc);
	void (*write_gdt_entry)(struct desc_struct *,
				int entrynum, const void *desc, int size);
	void (*write_idt_entry)(gate_desc *,
				int entrynum, const gate_desc *gate);
	void (*alloc_ldt)(struct desc_struct *ldt, unsigned entries);
	void (*free_ldt)(struct desc_struct *ldt, unsigned entries);

	void (*load_sp0)(struct tss_struct *tss, struct thread_struct *t);

	void (*set_iopl_mask)(unsigned mask);

	void (*wbinvd)(void);
	void (*io_delay)(void);

	/* cpuid emulation, mostly so that caps bits can be disabled */
	void (*cpuid)(unsigned int *eax, unsigned int *ebx,
		      unsigned int *ecx, unsigned int *edx);

	/* MSR, PMC and TSR operations.
	   err = 0/-EFAULT.  wrmsr returns 0/-EFAULT. */
	u64 (*read_msr_amd)(unsigned int msr, int *err);
	u64 (*read_msr)(unsigned int msr, int *err);
	int (*write_msr)(unsigned int msr, unsigned low, unsigned high);

	u64 (*read_tsc)(void);
	u64 (*read_pmc)(int counter);
	unsigned long long (*read_tscp)(unsigned int *aux);

	/*
	 * Atomically enable interrupts and return to userspace.  This
	 * is only ever used to return to 32-bit processes; in a
	 * 64-bit kernel, it's used for 32-on-64 compat processes, but
	 * never native 64-bit processes.  (Jump, not call.)
	 */
	void (*irq_enable_sysexit)(void);

	/*
	 * Switch to usermode gs and return to 64-bit usermode using
	 * sysret.  Only used in 64-bit kernels to return to 64-bit
	 * processes.  Usermode register state, including %rsp, must
	 * already be restored.
	 */
	void (*usergs_sysret64)(void);

	/*
	 * Switch to usermode gs and return to 32-bit usermode using
	 * sysret.  Used to return to 32-on-64 compat processes.
	 * Other usermode register state, including %esp, must already
	 * be restored.
	 */
	void (*usergs_sysret32)(void);

	/* Normal iret.  Jump to this with the standard iret stack
	   frame set up. */
	void (*iret)(void);

	void (*swapgs)(void);

	struct pv_lazy_ops lazy_mode;
};

struct pv_irq_ops {
	void (*init_IRQ)(void);

	/*
	 * Get/set interrupt state.  save_fl and restore_fl are only
	 * expected to use X86_EFLAGS_IF; all other bits
	 * returned from save_fl are undefined, and may be ignored by