x86, um: ... and asm-x86 move

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 184 insertions, 0 deletions

diff --git a/arch/x86/include/asm/kvm_x86_emulate.h b/arch/x86/include/asm/kvm_x86_emulate.h
new file mode 100644
index 000000000000..e2d9b030c1ac
--- /dev/null
+++ b/arch/x86/include/asm/kvm_x86_emulate.h
@@ -0,0 +1,184 @@
+/******************************************************************************
+ * 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
+
+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, void *val,
+			unsigned int bytes, struct kvm_vcpu *vcpu);
+
+	/*
+	 * 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 kvm_vcpu *vcpu);
+
+	/*
+	 * 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,
+			      const void *val,
+			      unsigned int bytes,
+			      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 kvm_vcpu *vcpu);
+
+};
+
+/* 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;
+	unsigned long val, orig_val, *ptr;
+};
+
+struct fetch_cache {
+	u8 data[15];
+	unsigned long start;
+	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 dst;
+	bool has_seg_override;
+	u8 seg_override;
+	unsigned int d;
+	unsigned long regs[NR_VCPU_REGS];
+	unsigned long eip;
+	/* modrm */
+	u8 modrm;
+	u8 modrm_mod;
+	u8 modrm_reg;
+	u8 modrm_rm;
+	u8 use_modrm_ea;
+	bool rip_relative;
+	unsigned long modrm_ea;
+	void *modrm_ptr;
+	unsigned long modrm_val;
+	struct fetch_cache fetch;
+};
+
+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;
+
+	/* Emulated execution mode, represented by an X86EMUL_MODE value. */
+	int mode;
+
+	u32 cs_base;
+
+	/* 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_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
+
+int x86_decode_insn(struct x86_emulate_ctxt *ctxt,
+		    struct x86_emulate_ops *ops);
+int x86_emulate_insn(struct x86_emulate_ctxt *ctxt,
+		     struct x86_emulate_ops *ops);
+
+#endif /* ASM_X86__KVM_X86_EMULATE_H */