1 /*- 2 * Copyright (c) 2012 NetApp, Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #ifndef _VMM_INSTRUCTION_EMUL_H_ 30 #define _VMM_INSTRUCTION_EMUL_H_ 31 32 /* 33 * The data structures 'vie' and 'vie_op' are meant to be opaque to the 34 * consumers of instruction decoding. The only reason why their contents 35 * need to be exposed is because they are part of the 'vm_exit' structure. 36 */ 37 struct vie_op { 38 uint8_t op_byte; /* actual opcode byte */ 39 uint8_t op_type; /* type of operation (e.g. MOV) */ 40 uint16_t op_flags; 41 }; 42 43 #define VIE_INST_SIZE 15 44 struct vie { 45 uint8_t inst[VIE_INST_SIZE]; /* instruction bytes */ 46 uint8_t num_valid; /* size of the instruction */ 47 uint8_t num_processed; 48 49 uint8_t rex_w:1, /* REX prefix */ 50 rex_r:1, 51 rex_x:1, 52 rex_b:1, 53 rex_present:1; 54 55 uint8_t mod:2, /* ModRM byte */ 56 reg:4, 57 rm:4; 58 59 uint8_t ss:2, /* SIB byte */ 60 index:4, 61 base:4; 62 63 uint8_t disp_bytes; 64 uint8_t imm_bytes; 65 66 uint8_t scale; 67 int base_register; /* VM_REG_GUEST_xyz */ 68 int index_register; /* VM_REG_GUEST_xyz */ 69 70 int64_t displacement; /* optional addr displacement */ 71 int64_t immediate; /* optional immediate operand */ 72 73 uint8_t decoded; /* set to 1 if successfully decoded */ 74 75 struct vie_op op; /* opcode description */ 76 }; 77 78 /* 79 * Callback functions to read and write memory regions. 80 */ 81 typedef int (*mem_region_read_t)(void *vm, int cpuid, uint64_t gpa, 82 uint64_t *rval, int rsize, void *arg); 83 84 typedef int (*mem_region_write_t)(void *vm, int cpuid, uint64_t gpa, 85 uint64_t wval, int wsize, void *arg); 86 87 /* 88 * Emulate the decoded 'vie' instruction. 89 * 90 * The callbacks 'mrr' and 'mrw' emulate reads and writes to the memory region 91 * containing 'gpa'. 'mrarg' is an opaque argument that is passed into the 92 * callback functions. 93 * 94 * 'void *vm' should be 'struct vm *' when called from kernel context and 95 * 'struct vmctx *' when called from user context. 96 * s 97 */ 98 int vmm_emulate_instruction(void *vm, int cpuid, uint64_t gpa, struct vie *vie, 99 mem_region_read_t mrr, mem_region_write_t mrw, 100 void *mrarg); 101 102 #ifdef _KERNEL 103 /* 104 * APIs to fetch and decode the instruction from nested page fault handler. 105 */ 106 int vmm_fetch_instruction(struct vm *vm, int cpuid, 107 uint64_t rip, int inst_length, uint64_t cr3, 108 struct vie *vie); 109 110 /* 111 * Decode the instruction fetched into 'vie' so it can be emulated. 112 * 113 * 'gla' is the guest linear address provided by the hardware assist 114 * that caused the nested page table fault. It is used to verify that 115 * the software instruction decoding is in agreement with the hardware. 116 * 117 * Some hardware assists do not provide the 'gla' to the hypervisor. 118 * To skip the 'gla' verification for this or any other reason pass 119 * in VIE_INVALID_GLA instead. 120 */ 121 #define VIE_INVALID_GLA (1UL << 63) /* a non-canonical address */ 122 int vmm_decode_instruction(struct vm *vm, int cpuid, 123 uint64_t gla, struct vie *vie); 124 #endif /* _KERNEL */ 125 126 #endif /* _VMM_INSTRUCTION_EMUL_H_ */ 127