--- /dev/null
+/******************************************************************************
+ * 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 __X86_EMULATE_H__
+#define __X86_EMULATE_H__
+
+struct x86_emulate_ctxt;
+
+/*
+ * 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 2 /* retry the instruction for some reason */
+#define X86EMUL_CMPXCHG_FAILED 2 /* cmpxchg did not see expected value */
+struct x86_emulate_ops {
+ /*
+ * read_std: Read bytes of standard (non-emulated/special) memory.
+ * Used for instruction fetch, stack operations, and others.
+ * @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,
+ unsigned long *val,
+ unsigned int bytes, struct x86_emulate_ctxt * ctxt);
+
+ /*
+ * write_std: Write bytes of standard (non-emulated/special) memory.
+ * Used for stack operations, and others.
+ * @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_std)(unsigned long addr,
+ unsigned long val,
+ unsigned int bytes, struct x86_emulate_ctxt * ctxt);
+
+ /*
+ * 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,
+ unsigned long *val,
+ unsigned int bytes,
+ struct x86_emulate_ctxt * ctxt);
+
+ /*
+ * write_emulated: Read bytes from 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,
+ unsigned long val,
+ unsigned int bytes,
+ struct x86_emulate_ctxt * ctxt);
+
+ /*
+ * 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,
+ unsigned long old,
+ unsigned long new,
+ unsigned int bytes,
+ struct x86_emulate_ctxt * ctxt);
+
+ /*
+ * cmpxchg8b_emulated: Emulate an atomic (LOCKed) CMPXCHG8B 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.
+ * NOTES:
+ * 1. This function is only ever called when emulating a real CMPXCHG8B.
+ * 2. This function is *never* called on x86/64 systems.
+ * 2. Not defining this function (i.e., specifying NULL) is equivalent
+ * to defining a function that always returns X86EMUL_UNHANDLEABLE.
+ */
+ int (*cmpxchg8b_emulated) (unsigned long addr,
+ unsigned long old_lo,
+ unsigned long old_hi,
+ unsigned long new_lo,
+ unsigned long new_hi,
+ struct x86_emulate_ctxt * ctxt);
+};
+
+struct cpu_user_regs;
+
+struct x86_emulate_ctxt {
+ /* Register state before/after emulation. */
+ struct kvm_vcpu *vcpu;
+
+ /* Linear faulting address (if emulating a page-faulting instruction). */
+ unsigned long eflags;
+ unsigned long cr2;
+
+ /* Emulated execution mode, represented by an X86EMUL_MODE value. */
+ int mode;
+
+ unsigned long cs_base;
+ unsigned long ds_base;
+ unsigned long es_base;
+ unsigned long ss_base;
+ unsigned long gs_base;
+ unsigned long fs_base;
+};
+
+/* Execution mode, passed to the emulator. */
+#define X86EMUL_MODE_REAL 0 /* Real 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(__i386__)
+#define X86EMUL_MODE_HOST X86EMUL_MODE_PROT32
+#elif defined(CONFIG_X86_64)
+#define X86EMUL_MODE_HOST X86EMUL_MODE_PROT64
+#endif
+
+/*
+ * x86_emulate_memop: Emulate an instruction that faulted attempting to
+ * read/write a 'special' memory area.
+ * Returns -1 on failure, 0 on success.
+ */
+int x86_emulate_memop(struct x86_emulate_ctxt *ctxt,
+ struct x86_emulate_ops *ops);
+
+/*
+ * Given the 'reg' portion of a ModRM byte, and a register block, return a
+ * pointer into the block that addresses the relevant register.
+ * @highbyte_regs specifies whether to decode AH,CH,DH,BH.
+ */
+void *decode_register(u8 modrm_reg, unsigned long *regs,
+ int highbyte_regs);
+
+#endif /* __X86_EMULATE_H__ */
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