arch/x86/include/asm/kvm_emulate.h - maze/linux - Git at Google

 /******************************************************************************
  * x86_emulate.h
  *
  * Generic x86 (32-bit and 64-bit) instruction decoder and emulator.
  *
  * Copyright (c) 2005 Keir Fraser
  *
  * From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4
  */

 #ifndef _ASM_X86_KVM_X86_EMULATE_H
 #define _ASM_X86_KVM_X86_EMULATE_H

 #include <asm/desc_defs.h>

 struct x86_emulate_ctxt;

 struct x86_exception {
 	u8 vector;
 	bool error_code_valid;
 	u16 error_code;
 	bool nested_page_fault;
 	u64 address; /* cr2 or nested page fault gpa */
 };

 /*
  * x86_emulate_ops:
  *
  * These operations represent the instruction emulator's interface to memory.
  * There are two categories of operation: those that act on ordinary memory
  * regions (*_std), and those that act on memory regions known to require
  * special treatment or emulation (*_emulated).
  *
  * The emulator assumes that an instruction accesses only one 'emulated memory'
  * location, that this location is the given linear faulting address (cr2), and
  * that this is one of the instruction's data operands. Instruction fetches and
  * stack operations are assumed never to access emulated memory. The emulator
  * automatically deduces which operand of a string-move operation is accessing
  * emulated memory, and assumes that the other operand accesses normal memory.
  *
  * NOTES:
  *  1. The emulator isn't very smart about emulated vs. standard memory.
  *     'Emulated memory' access addresses should be checked for sanity.
  *     'Normal memory' accesses may fault, and the caller must arrange to
  *     detect and handle reentrancy into the emulator via recursive faults.
  *     Accesses may be unaligned and may cross page boundaries.
  *  2. If the access fails (cannot emulate, or a standard access faults) then
  *     it is up to the memop to propagate the fault to the guest VM via
  *     some out-of-band mechanism, unknown to the emulator. The memop signals
  *     failure by returning X86EMUL_PROPAGATE_FAULT to the emulator, which will
  *     then immediately bail.
  *  3. Valid access sizes are 1, 2, 4 and 8 bytes. On x86/32 systems only
  *     cmpxchg8b_emulated need support 8-byte accesses.
  *  4. The emulator cannot handle 64-bit mode emulation on an x86/32 system.
  */
 /* Access completed successfully: continue emulation as normal. */
 #define X86EMUL_CONTINUE        0
 /* Access is unhandleable: bail from emulation and return error to caller. */
 #define X86EMUL_UNHANDLEABLE    1
 /* Terminate emulation but return success to the caller. */
 #define X86EMUL_PROPAGATE_FAULT 2 /* propagate a generated fault to guest */
 #define X86EMUL_RETRY_INSTR     3 /* retry the instruction for some reason */
 #define X86EMUL_CMPXCHG_FAILED  4 /* cmpxchg did not see expected value */
 #define X86EMUL_IO_NEEDED       5 /* IO is needed to complete emulation */

 struct x86_emulate_ops {
 	/*
 	 * read_std: Read bytes of standard (non-emulated/special) memory.
 	 *           Used for descriptor reading.
 	 *  @addr:  [IN ] Linear address from which to read.
 	 *  @val:   [OUT] Value read from memory, zero-extended to 'u_long'.
 	 *  @bytes: [IN ] Number of bytes to read from memory.
 	 */
 	int (*read_std)(unsigned long addr, void *val,
 			unsigned int bytes, struct kvm_vcpu *vcpu,
 			struct x86_exception *fault);

 	/*
 	 * write_std: Write bytes of standard (non-emulated/special) memory.
 	 *            Used for descriptor writing.
 	 *  @addr:  [IN ] Linear address to which to write.
 	 *  @val:   [OUT] Value write to memory, zero-extended to 'u_long'.
 	 *  @bytes: [IN ] Number of bytes to write to memory.
 	 */
 	int (*write_std)(unsigned long addr, void *val,
 			 unsigned int bytes, struct kvm_vcpu *vcpu,
 			 struct x86_exception *fault);
 	/*
 	 * fetch: Read bytes of standard (non-emulated/special) memory.
 	 *        Used for instruction fetch.
 	 *  @addr:  [IN ] Linear address from which to read.
 	 *  @val:   [OUT] Value read from memory, zero-extended to 'u_long'.
 	 *  @bytes: [IN ] Number of bytes to read from memory.
 	 */
 	int (*fetch)(unsigned long addr, void *val,
 		     unsigned int bytes, struct kvm_vcpu *vcpu,
 		     struct x86_exception *fault);

 	/*
 	 * read_emulated: Read bytes from emulated/special memory area.
 	 *  @addr:  [IN ] Linear address from which to read.
 	 *  @val:   [OUT] Value read from memory, zero-extended to 'u_long'.
 	 *  @bytes: [IN ] Number of bytes to read from memory.
 	 */
 	int (*read_emulated)(unsigned long addr,
 			     void *val,
 			     unsigned int bytes,
 			     struct x86_exception *fault,
 			     struct kvm_vcpu *vcpu);

 	/*
 	 * write_emulated: Write bytes to emulated/special memory area.
 	 *  @addr:  [IN ] Linear address to which to write.
 	 *  @val:   [IN ] Value to write to memory (low-order bytes used as
 	 *                required).
 	 *  @bytes: [IN ] Number of bytes to write to memory.
 	 */
 	int (*write_emulated)(unsigned long addr,
 			      const void *val,
 			      unsigned int bytes,
 			      struct x86_exception *fault,
 			      struct kvm_vcpu *vcpu);

 	/*
 	 * cmpxchg_emulated: Emulate an atomic (LOCKed) CMPXCHG operation on an
 	 *                   emulated/special memory area.
 	 *  @addr:  [IN ] Linear address to access.
 	 *  @old:   [IN ] Value expected to be current at @addr.
 	 *  @new:   [IN ] Value to write to @addr.
 	 *  @bytes: [IN ] Number of bytes to access using CMPXCHG.
 	 */
 	int (*cmpxchg_emulated)(unsigned long addr,
 				const void *old,
 				const void *new,
 				unsigned int bytes,
 				struct x86_exception *fault,
 				struct kvm_vcpu *vcpu);

 	int (*pio_in_emulated)(int size, unsigned short port, void *val,
 			       unsigned int count, struct kvm_vcpu *vcpu);

 	int (*pio_out_emulated)(int size, unsigned short port, const void *val,
 				unsigned int count, struct kvm_vcpu *vcpu);

 	bool (*get_cached_descriptor)(struct desc_struct *desc, u32 *base3,
 				      int seg, struct kvm_vcpu *vcpu);
 	void (*set_cached_descriptor)(struct desc_struct *desc, u32 base3,
 				      int seg, struct kvm_vcpu *vcpu);
 	u16 (*get_segment_selector)(int seg, struct kvm_vcpu *vcpu);
 	void (*set_segment_selector)(u16 sel, int seg, struct kvm_vcpu *vcpu);
 	unsigned long (*get_cached_segment_base)(int seg, struct kvm_vcpu *vcpu);
 	void (*get_gdt)(struct desc_ptr *dt, struct kvm_vcpu *vcpu);
 	void (*get_idt)(struct desc_ptr *dt, struct kvm_vcpu *vcpu);
 	ulong (*get_cr)(int cr, struct kvm_vcpu *vcpu);
 	int (*set_cr)(int cr, ulong val, struct kvm_vcpu *vcpu);
 	int (*cpl)(struct kvm_vcpu *vcpu);
 	int (*get_dr)(int dr, unsigned long *dest, struct kvm_vcpu *vcpu);
 	int (*set_dr)(int dr, unsigned long value, struct kvm_vcpu *vcpu);
 	int (*set_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 data);
 	int (*get_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata);
 };

 /* Type, address-of, and value of an instruction's operand. */
 struct operand {
 	enum { OP_REG, OP_MEM, OP_IMM, OP_NONE } type;
 	unsigned int bytes;
 	union {
 		unsigned long orig_val;
 		u64 orig_val64;
 	};
 	union {
 		unsigned long *reg;
 		struct segmented_address {
 			ulong ea;
 			unsigned seg;
 		} mem;
 	} addr;
 	union {
 		unsigned long val;
 		u64 val64;
 		char valptr[sizeof(unsigned long) + 2];
 	};
 };

 struct fetch_cache {
 	u8 data[15];
 	unsigned long start;
 	unsigned long end;
 };

 struct read_cache {
 	u8 data[1024];
 	unsigned long pos;
 	unsigned long end;
 };

 struct decode_cache {
 	u8 twobyte;
 	u8 b;
 	u8 lock_prefix;
 	u8 rep_prefix;
 	u8 op_bytes;
 	u8 ad_bytes;
 	u8 rex_prefix;
 	struct operand src;
 	struct operand src2;
 	struct operand dst;
 	bool has_seg_override;
 	u8 seg_override;
 	unsigned int d;
 	int (*execute)(struct x86_emulate_ctxt *ctxt);
 	unsigned long regs[NR_VCPU_REGS];
 	unsigned long eip;
 	/* modrm */
 	u8 modrm;
 	u8 modrm_mod;
 	u8 modrm_reg;
 	u8 modrm_rm;
 	u8 modrm_seg;
 	bool rip_relative;
 	struct fetch_cache fetch;
 	struct read_cache io_read;
 	struct read_cache mem_read;
 };

 struct x86_emulate_ctxt {
 	struct x86_emulate_ops *ops;

 	/* Register state before/after emulation. */
 	struct kvm_vcpu *vcpu;

 	unsigned long eflags;
 	unsigned long eip; /* eip before instruction emulation */
 	/* Emulated execution mode, represented by an X86EMUL_MODE value. */
 	int mode;
 	u32 cs_base;

 	/* interruptibility state, as a result of execution of STI or MOV SS */
 	int interruptibility;

 	bool perm_ok; /* do not check permissions if true */
 	bool only_vendor_specific_insn;

 	bool have_exception;
 	struct x86_exception exception;

 	/* decode cache */
 	struct decode_cache decode;
 };

 /* Repeat String Operation Prefix */
 #define REPE_PREFIX	1
 #define REPNE_PREFIX	2

 /* Execution mode, passed to the emulator. */
 #define X86EMUL_MODE_REAL     0	/* Real mode.             */
 #define X86EMUL_MODE_VM86     1	/* Virtual 8086 mode.     */
 #define X86EMUL_MODE_PROT16   2	/* 16-bit protected mode. */
 #define X86EMUL_MODE_PROT32   4	/* 32-bit protected mode. */
 #define X86EMUL_MODE_PROT64   8	/* 64-bit (long) mode.    */

 /* Host execution mode. */
 #if defined(CONFIG_X86_32)
 #define X86EMUL_MODE_HOST X86EMUL_MODE_PROT32
 #elif defined(CONFIG_X86_64)
 #define X86EMUL_MODE_HOST X86EMUL_MODE_PROT64
 #endif

 int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len);
 #define EMULATION_FAILED -1
 #define EMULATION_OK 0
 #define EMULATION_RESTART 1
 int x86_emulate_insn(struct x86_emulate_ctxt *ctxt);
 int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
 			 u16 tss_selector, int reason,
 			 bool has_error_code, u32 error_code);
 int emulate_int_real(struct x86_emulate_ctxt *ctxt,
 		     struct x86_emulate_ops *ops, int irq);
 #endif /* _ASM_X86_KVM_X86_EMULATE_H */
	/******************************************************************************
	* x86_emulate.h
	*
	* Generic x86 (32-bit and 64-bit) instruction decoder and emulator.
	*
	* Copyright (c) 2005 Keir Fraser
	*
	* From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4
	*/

	#ifndef _ASM_X86_KVM_X86_EMULATE_H
	#define _ASM_X86_KVM_X86_EMULATE_H

	#include <asm/desc_defs.h>

	struct x86_emulate_ctxt;

	struct x86_exception {
	u8 vector;
	bool error_code_valid;
	u16 error_code;
	bool nested_page_fault;
	u64 address; /* cr2 or nested page fault gpa */
	};

	/*
	* x86_emulate_ops:
	*
	* These operations represent the instruction emulator's interface to memory.
	* There are two categories of operation: those that act on ordinary memory
	* regions (*_std), and those that act on memory regions known to require
	* special treatment or emulation (*_emulated).
	*
	* The emulator assumes that an instruction accesses only one 'emulated memory'
	* location, that this location is the given linear faulting address (cr2), and
	* that this is one of the instruction's data operands. Instruction fetches and
	* stack operations are assumed never to access emulated memory. The emulator
	* automatically deduces which operand of a string-move operation is accessing
	* emulated memory, and assumes that the other operand accesses normal memory.
	*
	* NOTES:
	* 1. The emulator isn't very smart about emulated vs. standard memory.
	* 'Emulated memory' access addresses should be checked for sanity.
	* 'Normal memory' accesses may fault, and the caller must arrange to
	* detect and handle reentrancy into the emulator via recursive faults.
	* Accesses may be unaligned and may cross page boundaries.
	* 2. If the access fails (cannot emulate, or a standard access faults) then
	* it is up to the memop to propagate the fault to the guest VM via
	* some out-of-band mechanism, unknown to the emulator. The memop signals
	* failure by returning X86EMUL_PROPAGATE_FAULT to the emulator, which will
	* then immediately bail.
	* 3. Valid access sizes are 1, 2, 4 and 8 bytes. On x86/32 systems only
	* cmpxchg8b_emulated need support 8-byte accesses.
	* 4. The emulator cannot handle 64-bit mode emulation on an x86/32 system.
	*/
	/* Access completed successfully: continue emulation as normal. */
	#define X86EMUL_CONTINUE 0
	/* Access is unhandleable: bail from emulation and return error to caller. */
	#define X86EMUL_UNHANDLEABLE 1
	/* Terminate emulation but return success to the caller. */
	#define X86EMUL_PROPAGATE_FAULT 2 /* propagate a generated fault to guest */
	#define X86EMUL_RETRY_INSTR 3 /* retry the instruction for some reason */
	#define X86EMUL_CMPXCHG_FAILED 4 /* cmpxchg did not see expected value */
	#define X86EMUL_IO_NEEDED 5 /* IO is needed to complete emulation */

	struct x86_emulate_ops {
	/*
	* read_std: Read bytes of standard (non-emulated/special) memory.
	* Used for descriptor reading.
	* @addr: [IN ] Linear address from which to read.
	* @val: [OUT] Value read from memory, zero-extended to 'u_long'.
	* @bytes: [IN ] Number of bytes to read from memory.
	*/
	int (read_std)(unsigned long addr, void val,
	unsigned int bytes, struct kvm_vcpu *vcpu,
	struct x86_exception *fault);

	/*
	* write_std: Write bytes of standard (non-emulated/special) memory.
	* Used for descriptor writing.
	* @addr: [IN ] Linear address to which to write.
	* @val: [OUT] Value write to memory, zero-extended to 'u_long'.
	* @bytes: [IN ] Number of bytes to write to memory.
	*/
	int (write_std)(unsigned long addr, void val,
	unsigned int bytes, struct kvm_vcpu *vcpu,
	struct x86_exception *fault);
	/*
	* fetch: Read bytes of standard (non-emulated/special) memory.
	* Used for instruction fetch.
	* @addr: [IN ] Linear address from which to read.
	* @val: [OUT] Value read from memory, zero-extended to 'u_long'.
	* @bytes: [IN ] Number of bytes to read from memory.
	*/
	int (fetch)(unsigned long addr, void val,
	unsigned int bytes, struct kvm_vcpu *vcpu,
	struct x86_exception *fault);

	/*
	* read_emulated: Read bytes from emulated/special memory area.
	* @addr: [IN ] Linear address from which to read.
	* @val: [OUT] Value read from memory, zero-extended to 'u_long'.
	* @bytes: [IN ] Number of bytes to read from memory.
	*/
	int (*read_emulated)(unsigned long addr,
	void *val,
	unsigned int bytes,
	struct x86_exception *fault,
	struct kvm_vcpu *vcpu);

	/*
	* write_emulated: Write bytes to emulated/special memory area.
	* @addr: [IN ] Linear address to which to write.
	* @val: [IN ] Value to write to memory (low-order bytes used as
	* required).
	* @bytes: [IN ] Number of bytes to write to memory.
	*/
	int (*write_emulated)(unsigned long addr,
	const void *val,
	unsigned int bytes,
	struct x86_exception *fault,
	struct kvm_vcpu *vcpu);

	/*
	* cmpxchg_emulated: Emulate an atomic (LOCKed) CMPXCHG operation on an
	* emulated/special memory area.
	* @addr: [IN ] Linear address to access.
	* @old: [IN ] Value expected to be current at @addr.
	* @new: [IN ] Value to write to @addr.
	* @bytes: [IN ] Number of bytes to access using CMPXCHG.
	*/
	int (*cmpxchg_emulated)(unsigned long addr,
	const void *old,
	const void *new,
	unsigned int bytes,
	struct x86_exception *fault,
	struct kvm_vcpu *vcpu);

	int (pio_in_emulated)(int size, unsigned short port, void val,
	unsigned int count, struct kvm_vcpu *vcpu);

	int (pio_out_emulated)(int size, unsigned short port, const void val,
	unsigned int count, struct kvm_vcpu *vcpu);

	bool (get_cached_descriptor)(struct desc_struct desc, u32 *base3,
	int seg, struct kvm_vcpu *vcpu);
	void (set_cached_descriptor)(struct desc_struct desc, u32 base3,
	int seg, struct kvm_vcpu *vcpu);
	u16 (get_segment_selector)(int seg, struct kvm_vcpu vcpu);
	void (set_segment_selector)(u16 sel, int seg, struct kvm_vcpu vcpu);
	unsigned long (get_cached_segment_base)(int seg, struct kvm_vcpu vcpu);
	void (get_gdt)(struct desc_ptr dt, struct kvm_vcpu *vcpu);
	void (get_idt)(struct desc_ptr dt, struct kvm_vcpu *vcpu);
	ulong (get_cr)(int cr, struct kvm_vcpu vcpu);
	int (set_cr)(int cr, ulong val, struct kvm_vcpu vcpu);
	int (cpl)(struct kvm_vcpu vcpu);
	int (get_dr)(int dr, unsigned long dest, struct kvm_vcpu *vcpu);
	int (set_dr)(int dr, unsigned long value, struct kvm_vcpu vcpu);
	int (set_msr)(struct kvm_vcpu vcpu, u32 msr_index, u64 data);
	int (get_msr)(struct kvm_vcpu vcpu, u32 msr_index, u64 *pdata);
	};

	/* Type, address-of, and value of an instruction's operand. */
	struct operand {
	enum { OP_REG, OP_MEM, OP_IMM, OP_NONE } type;
	unsigned int bytes;
	union {
	unsigned long orig_val;
	u64 orig_val64;
	};
	union {
	unsigned long *reg;
	struct segmented_address {
	ulong ea;
	unsigned seg;
	} mem;
	} addr;
	union {
	unsigned long val;
	u64 val64;
	char valptr[sizeof(unsigned long) + 2];
	};
	};

	struct fetch_cache {
	u8 data[15];
	unsigned long start;
	unsigned long end;
	};

	struct read_cache {
	u8 data[1024];
	unsigned long pos;
	unsigned long end;
	};

	struct decode_cache {
	u8 twobyte;
	u8 b;
	u8 lock_prefix;
	u8 rep_prefix;
	u8 op_bytes;
	u8 ad_bytes;
	u8 rex_prefix;
	struct operand src;
	struct operand src2;
	struct operand dst;
	bool has_seg_override;
	u8 seg_override;
	unsigned int d;
	int (execute)(struct x86_emulate_ctxt ctxt);
	unsigned long regs[NR_VCPU_REGS];
	unsigned long eip;
	/* modrm */
	u8 modrm;
	u8 modrm_mod;
	u8 modrm_reg;
	u8 modrm_rm;
	u8 modrm_seg;
	bool rip_relative;
	struct fetch_cache fetch;
	struct read_cache io_read;
	struct read_cache mem_read;
	};

	struct x86_emulate_ctxt {
	struct x86_emulate_ops *ops;

	/* Register state before/after emulation. */
	struct kvm_vcpu *vcpu;

	unsigned long eflags;
	unsigned long eip; /* eip before instruction emulation */
	/* Emulated execution mode, represented by an X86EMUL_MODE value. */
	int mode;
	u32 cs_base;

	/* interruptibility state, as a result of execution of STI or MOV SS */
	int interruptibility;

	bool perm_ok; /* do not check permissions if true */
	bool only_vendor_specific_insn;

	bool have_exception;
	struct x86_exception exception;

	/* decode cache */
	struct decode_cache decode;
	};

	/* Repeat String Operation Prefix */
	#define REPE_PREFIX 1
	#define REPNE_PREFIX 2

	/* Execution mode, passed to the emulator. */
	#define X86EMUL_MODE_REAL 0 /* Real mode. */
	#define X86EMUL_MODE_VM86 1 /* Virtual 8086 mode. */
	#define X86EMUL_MODE_PROT16 2 /* 16-bit protected mode. */
	#define X86EMUL_MODE_PROT32 4 /* 32-bit protected mode. */
	#define X86EMUL_MODE_PROT64 8 /* 64-bit (long) mode. */

	/* Host execution mode. */
	#if defined(CONFIG_X86_32)
	#define X86EMUL_MODE_HOST X86EMUL_MODE_PROT32
	#elif defined(CONFIG_X86_64)
	#define X86EMUL_MODE_HOST X86EMUL_MODE_PROT64
	#endif

	int x86_decode_insn(struct x86_emulate_ctxt ctxt, void insn, int insn_len);
	#define EMULATION_FAILED -1
	#define EMULATION_OK 0
	#define EMULATION_RESTART 1
	int x86_emulate_insn(struct x86_emulate_ctxt *ctxt);
	int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
	u16 tss_selector, int reason,
	bool has_error_code, u32 error_code);
	int emulate_int_real(struct x86_emulate_ctxt *ctxt,
	struct x86_emulate_ops *ops, int irq);
	#endif /* _ASM_X86_KVM_X86_EMULATE_H */