* Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org>
* All rights reserved.
*
- * Author: Jack Lange <jarusl@cs.northwestern.edu>
+ * Authors: Jack Lange <jarusl@cs.northwestern.edu>
+ * Peter Dinda <pdinda@northwestern.edu> (full hook/string ops)
*
* This is free software. You are permitted to use,
* redistribute, and modify it as specified in the file "V3VEE_LICENSE".
#include <palacios/vmm.h>
#include <palacios/vmm_emulator.h>
-#include <palacios/vm_guest_mem.h>
#include <palacios/vmm_decoder.h>
-#include <palacios/vmm_paging.h>
#include <palacios/vmm_instr_emulator.h>
+#include <palacios/vmm_ctrl_regs.h>
-#ifndef CONFIG_DEBUG_EMULATOR
+#ifndef V3_CONFIG_DEBUG_EMULATOR
#undef PrintDebug
#define PrintDebug(fmt, args...)
#endif
-static int run_op(struct guest_info * info, v3_op_type_t op_type, addr_t src_addr, addr_t dst_addr, int src_op_size, int dst_op_size);
-
-// We emulate up to the next 4KB page boundry
-static int emulate_string_write_op(struct guest_info * info, struct x86_instr * dec_instr,
- addr_t write_gva, addr_t write_gpa, addr_t dst_addr,
- int (*write_fn)(struct guest_info * core, addr_t guest_addr, void * src, uint_t length, void * priv_data),
- void * priv_data) {
- uint_t emulation_length = 0;
- uint_t emulation_iter_cnt = 0;
- addr_t tmp_rcx = 0;
- addr_t src_addr = 0;
-
- if (info->shdw_pg_mode == SHADOW_PAGING) {
- if (dec_instr->dst_operand.operand != write_gva) {
- PrintError("Inconsistency between Pagefault and Instruction Decode XED_ADDR=%p, PF_ADDR=%p\n",
- (void *)dec_instr->dst_operand.operand, (void *)write_gva);
- return -1;
- }
- } else {
- // Nested paging (Need check??)
- }
-
- /*emulation_length = ( (dec_instr->str_op_length < (0x1000 - PAGE_OFFSET_4KB(write_gva))) ?
- dec_instr->str_op_length :
- (0x1000 - PAGE_OFFSET_4KB(write_gva)));*/
-
- if ((dec_instr->str_op_length * (dec_instr->dst_operand.size)) < (0x1000 - PAGE_OFFSET_4KB(write_gva))) {
- emulation_length = dec_instr->str_op_length * dec_instr->dst_operand.size;
- } else {
- emulation_length = (0x1000 - PAGE_OFFSET_4KB(write_gva));
- PrintError("Warning: emulate_string_write_op emulating %u length operation, but request is for %u length\n",
- emulation_length, (uint32_t)(dec_instr->str_op_length*(dec_instr->dst_operand.size)));
- }
-
- /* ** Fix emulation length so that it doesn't overrun over the src page either ** */
- emulation_iter_cnt = emulation_length / dec_instr->dst_operand.size;
- tmp_rcx = emulation_iter_cnt;
-
- if (dec_instr->op_type == V3_OP_MOVS) {
-
- // figure out addresses here....
- if (info->mem_mode == PHYSICAL_MEM) {
- if (v3_gpa_to_hva(info, dec_instr->src_operand.operand, &src_addr) == -1) {
- PrintError("Could not translate write Source (Physical) to host VA\n");
- return -1;
- }
- } else {
- if (v3_gva_to_hva(info, dec_instr->src_operand.operand, &src_addr) == -1) {
- PrintError("Could not translate write Source (Virtual) to host VA\n");
- return -1;
- }
- }
-
- if (dec_instr->dst_operand.size == 1) {
- movs8((addr_t *)&dst_addr, &src_addr, &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
- } else if (dec_instr->dst_operand.size == 2) {
- movs16((addr_t *)&dst_addr, &src_addr, &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
- } else if (dec_instr->dst_operand.size == 4) {
- movs32((addr_t *)&dst_addr, &src_addr, &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
-#ifdef __V3_64BIT__
- } else if (dec_instr->dst_operand.size == 8) {
- movs64((addr_t *)&dst_addr, &src_addr, &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
-#endif
- } else {
- PrintError("Invalid operand length\n");
- return -1;
- }
-
- info->vm_regs.rdi += emulation_length;
- info->vm_regs.rsi += emulation_length;
-
- // RCX is only modified if the rep prefix is present
- if (dec_instr->prefixes.rep == 1) {
- info->vm_regs.rcx -= emulation_iter_cnt;
- }
-
- } else if (dec_instr->op_type == V3_OP_STOS) {
-
- if (dec_instr->dst_operand.size == 1) {
- stos8((addr_t *)&dst_addr, (addr_t *)&(info->vm_regs.rax), &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
- } else if (dec_instr->dst_operand.size == 2) {
- stos16((addr_t *)&dst_addr, (addr_t *)&(info->vm_regs.rax), &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
- } else if (dec_instr->dst_operand.size == 4) {
- stos32((addr_t *)&dst_addr, (addr_t *)&(info->vm_regs.rax), &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
-#ifdef __V3_64BIT__
- } else if (dec_instr->dst_operand.size == 8) {
- stos64((addr_t *)&dst_addr, (addr_t *)&(info->vm_regs.rax), &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
-#endif
- } else {
- PrintError("Invalid operand length\n");
- return -1;
- }
-
- info->vm_regs.rdi += emulation_length;
-
- // RCX is only modified if the rep prefix is present
- if (dec_instr->prefixes.rep == 1) {
- info->vm_regs.rcx -= emulation_iter_cnt;
- }
-
- } else {
- PrintError("Unimplemented String operation\n");
- return -1;
- }
-
- if (write_fn(info, write_gpa, (void *)dst_addr, emulation_length, priv_data) != emulation_length) {
- PrintError("Did not fully read hooked data\n");
- return -1;
- }
-
- if (emulation_length == dec_instr->str_op_length) {
- info->rip += dec_instr->instr_length;
- }
-
- return emulation_length;
-}
-
-
-
-/*
- This function is intended to handle pure read hooks, pure write hook, and full hooks,
- with and without backing memory for writes
-
- read_fn == NULL
- orig_src_addr == NULL => data at read_gpa is read
- orig_src_addr != NULL => data at orig_src_addr is read
- read_fn != NULL data is collected using read_fn
-
- write_fn == NULL
- orig_dst_addr == NULL => data is written to write_gpa
- orig_dst_addr != NULL => data is written to orig_dst_addr
- write_fn != NULL
- orig_dst_addr == NULL => data is sent to write_fn
- orig_dst_addr != NULL => data is written to orig_dst_addr, then via write_fn
-
-
-*/
-static int emulate_string_op(struct guest_info * info, struct x86_instr * dec_instr,
- addr_t read_gva, addr_t read_gpa, addr_t orig_src_addr,
- addr_t write_gva, addr_t write_gpa, addr_t orig_dst_addr,
- int (*read_fn)(struct guest_info * core, addr_t guest_addr, void * src, uint_t length, void * priv_data),
- int (*write_fn)(struct guest_info * core, addr_t guest_addr, void * dst, uint_t length, void * priv_data),
- void * priv_data)
-{
- uint_t src_emulation_length = 0;
- uint_t dst_emulation_length = 0;
- uint_t emulation_length = 0;
- uint_t emulation_iter_cnt = 0;
- addr_t tmp_rcx = 0;
- addr_t src_addr, dst_addr;
-
-
- // Sanity check the decoded instruction
-
- if (info->shdw_pg_mode == SHADOW_PAGING) {
- if (!read_fn && (dec_instr->src_operand.operand != read_gva)) {
- PrintError("Inconsistency between Pagefault and Instruction Decode XED_ADDR=%p, PF_ADDR=%p (Read)\n",
- (void *)dec_instr->src_operand.operand, (void *)read_gva);
- return -1;
- }
- if (!write_fn && (dec_instr->dst_operand.operand != write_gva)) {
- PrintError("Inconsistency between Pagefault and Instruction Decode XED_ADDR=%p, PF_ADDR=%p (Write)\n",
- (void *)dec_instr->dst_operand.operand, (void *)write_gva);
- return -1;
- }
- } else {
- // Nested paging (Need check??)
- }
-
-
- if (dec_instr->src_operand.size != dec_instr->dst_operand.size) {
- PrintError("Source and Destination Operands are of different sizes\n");
- return -1;
- }
-
-
- // We will only read up to the next page boundary
-
- if ((dec_instr->str_op_length * (dec_instr->src_operand.size)) < (0x1000 - PAGE_OFFSET_4KB(read_gva))) {
- src_emulation_length = dec_instr->str_op_length * dec_instr->src_operand.size;
- } else {
- src_emulation_length = (0x1000 - PAGE_OFFSET_4KB(read_gva));
- PrintError("Warning: emulate_string_op emulating src of %u length operation, but request is for %u length\n",
- src_emulation_length, (uint32_t) (dec_instr->str_op_length*(dec_instr->src_operand.size)));
- }
-
- // We will only write up to the next page boundary
-
- if ((dec_instr->str_op_length * (dec_instr->dst_operand.size)) < (0x1000 - PAGE_OFFSET_4KB(write_gva))) {
- dst_emulation_length = dec_instr->str_op_length * dec_instr->dst_operand.size;
- } else {
- dst_emulation_length = (0x1000 - PAGE_OFFSET_4KB(write_gva));
- PrintError("Warning: emulate_string_op emulating dst of %u length operation, but request is for %u length\n",
- dst_emulation_length, (uint32_t) (dec_instr->str_op_length*(dec_instr->dst_operand.size)));
- }
-
- // We will only copy the minimum of what is available to be read or written
-
- if (src_emulation_length<dst_emulation_length) {
- emulation_length=src_emulation_length;
- PrintError("Warning: emulate_string_op has src length %u but dst length %u\n", src_emulation_length, dst_emulation_length);
- } else if (src_emulation_length>dst_emulation_length) {
- emulation_length=dst_emulation_length;
- PrintError("Warning: emulate_string_op has src length %u but dst length %u\n", src_emulation_length, dst_emulation_length);
- } else {
- // equal
- emulation_length=src_emulation_length;
- }
-
-
- // Fetch the data
-
- if (read_fn) {
- src_addr = (addr_t) V3_Malloc(emulation_length); // hideous - should reuse memory
- if (!src_addr) {
- PrintError("Unable to allocate space for read operation in emulate_string_read_op\n");
- return -1;
- }
- if (read_fn(info, read_gpa, (void *)src_addr, emulation_length, priv_data) != emulation_length) {
- PrintError("Did not fully read hooked data in emulate_string_op\n");
- return -1;
- }
- } else {
- if (orig_src_addr) {
- src_addr=orig_src_addr;
- } else {
- if (info->mem_mode == PHYSICAL_MEM) {
- if (v3_gpa_to_hva(info, dec_instr->src_operand.operand, &src_addr) == -1) {
- PrintError("Could not translate write Source (Physical) to host VA\n");
- return -1;
- }
- } else {
- if (v3_gva_to_hva(info, dec_instr->src_operand.operand, &src_addr) == -1) {
- PrintError("Could not translate write Source (Virtual) to host VA\n");
- return -1;
- }
- }
- }
- }
-
- // Now src_addr points to the fetched data in HVA
-
- // Allocate space for the write, in case we need to copy out later
- if (write_fn) {
- if (orig_dst_addr) {
- dst_addr=orig_dst_addr;
- } else {
- dst_addr = (addr_t) V3_Malloc(emulation_length); // yuck
- if (!dst_addr) {
- PrintError("Unable to allocate space for write operation in emulate_string_op\n");
- if (read_fn) {
- V3_Free((void*)src_addr);
- }
- return -1;
- }
- }
- } else {
- if (orig_dst_addr) {
- dst_addr=orig_dst_addr;
- } else {
- if (info->mem_mode == PHYSICAL_MEM) {
- if (v3_gpa_to_hva(info, dec_instr->dst_operand.operand, &dst_addr) == -1) {
- PrintError("Could not translate write Dest (Physical) to host VA\n");
- return -1;
- }
- } else {
- if (v3_gva_to_hva(info, dec_instr->dst_operand.operand, &dst_addr) == -1) {
- PrintError("Could not translate write Dest (Virtual) to host VA\n");
- return -1;
- }
- }
- }
- }
-
- // Now dst_addr points to where we will copy the data
-
- // How many items to copy
- emulation_iter_cnt = emulation_length / dec_instr->dst_operand.size;
- tmp_rcx = emulation_iter_cnt;
-
-
- switch (dec_instr->op_type) {
-
- case V3_OP_MOVS: {
-
- if (dec_instr->dst_operand.size == 1) {
- movs8((addr_t *)&dst_addr, &src_addr, &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
- } else if (dec_instr->dst_operand.size == 2) {
- movs16((addr_t *)&dst_addr, &src_addr, &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
- } else if (dec_instr->dst_operand.size == 4) {
- movs32((addr_t *)&dst_addr, &src_addr, &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
-#ifdef __V3_64BIT__
- } else if (dec_instr->dst_operand.size == 8) {
- movs64((addr_t *)&dst_addr, &src_addr, &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
-#endif
- } else {
- PrintError("Invalid operand length\n");
- return -1;
- }
-
- // Can't these count down too? - PAD
-
- info->vm_regs.rdi += emulation_length;
- info->vm_regs.rsi += emulation_length;
-
- // RCX is only modified if the rep prefix is present
- if (dec_instr->prefixes.rep == 1) {
- info->vm_regs.rcx -= emulation_iter_cnt;
- }
-
- }
- break;
-
- case V3_OP_STOS: {
-
- if (dec_instr->dst_operand.size == 1) {
- stos8((addr_t *)&dst_addr, (addr_t *)&(info->vm_regs.rax), &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
- } else if (dec_instr->dst_operand.size == 2) {
- stos16((addr_t *)&dst_addr, (addr_t *)&(info->vm_regs.rax), &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
- } else if (dec_instr->dst_operand.size == 4) {
- stos32((addr_t *)&dst_addr, (addr_t *)&(info->vm_regs.rax), &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
-#ifdef __V3_64BIT__
- } else if (dec_instr->dst_operand.size == 8) {
- stos64((addr_t *)&dst_addr, (addr_t *)&(info->vm_regs.rax), &tmp_rcx, (addr_t *)&(info->ctrl_regs.rflags));
-#endif
- } else {
- PrintError("Invalid operand length\n");
- return -1;
- }
-
- info->vm_regs.rdi += emulation_length;
-
- // RCX is only modified if the rep prefix is present
- if (dec_instr->prefixes.rep == 1) {
- info->vm_regs.rcx -= emulation_iter_cnt;
- }
-
- }
- break;
-
- default: {
- PrintError("Unimplemented String operation\n");
- return -1;
- }
- break;
- }
-
- // At this point, the data has been written over dst_addr, which
- // is either our temporary buffer, or it's the requested target in orig_dst_addr
-
- if (write_fn) {
- if (write_fn(info, write_gpa, (void *)dst_addr, emulation_length, priv_data) != emulation_length) {
- PrintError("Did not fully write hooked data\n");
- return -1;
- }
- }
-
- if (emulation_length == dec_instr->str_op_length) {
- info->rip += dec_instr->instr_length;
- }
-
-
- // Delete temporary buffers
- if (read_fn) {
- V3_Free((void*)src_addr);
- }
- if (write_fn && !orig_dst_addr) {
- V3_Free((void*)dst_addr);
- }
-
-
- return emulation_length;
-}
-
-
-
-
-
-static int emulate_xchg_write_op(struct guest_info * info, struct x86_instr * dec_instr,
- addr_t write_gva, addr_t write_gpa, addr_t dst_addr,
- int (*write_fn)(struct guest_info * core, addr_t guest_addr, void * src, uint_t length, void * priv_data),
- void * priv_data) {
- addr_t src_addr = 0;
- addr_t em_dst_addr = 0;
- int src_op_len = 0;
- int dst_op_len = 0;
- PrintDebug("Emulating XCHG write\n");
-
- if (dec_instr->src_operand.type == MEM_OPERAND) {
- if (info->shdw_pg_mode == SHADOW_PAGING) {
- if (dec_instr->src_operand.operand != write_gva) {
- PrintError("XCHG: Inconsistency between Pagefault and Instruction Decode XED_ADDR=%p, PF_ADDR=%p\n",
- (void *)dec_instr->src_operand.operand, (void *)write_gva);
- return -1;
- }
- }
-
- src_addr = dst_addr;
- } else if (dec_instr->src_operand.type == REG_OPERAND) {
- src_addr = dec_instr->src_operand.operand;
- } else {
- src_addr = (addr_t)&(dec_instr->src_operand.operand);
- }
-
-
-
- if (dec_instr->dst_operand.type == MEM_OPERAND) {
- if (info->shdw_pg_mode == SHADOW_PAGING) {
- if (dec_instr->dst_operand.operand != write_gva) {
- PrintError("XCHG: Inconsistency between Pagefault and Instruction Decode XED_ADDR=%p, PF_ADDR=%p\n",
- (void *)dec_instr->dst_operand.operand, (void *)write_gva);
- return -1;
- }
- } else {
- //check that the operand (GVA) maps to the the faulting GPA
- }
-
- em_dst_addr = dst_addr;
- } else if (dec_instr->src_operand.type == REG_OPERAND) {
- em_dst_addr = dec_instr->src_operand.operand;
- } else {
- em_dst_addr = (addr_t)&(dec_instr->src_operand.operand);
- }
-
- dst_op_len = dec_instr->dst_operand.size;
- src_op_len = dec_instr->src_operand.size;
-
- PrintDebug("Dst_Addr = %p, SRC operand = %p\n",
- (void *)dst_addr, (void *)src_addr);
-
-
- if (run_op(info, dec_instr->op_type, src_addr, em_dst_addr, src_op_len, dst_op_len) == -1) {
- PrintError("Instruction Emulation Failed\n");
- return -1;
- }
-
- if (write_fn(info, write_gpa, (void *)dst_addr, dst_op_len, priv_data) != dst_op_len) {
- PrintError("Did not fully write hooked data\n");
- return -1;
- }
-
- info->rip += dec_instr->instr_length;
-
- return dst_op_len;
-}
-
-
-
-static int emulate_xchg_read_op(struct guest_info * info, struct x86_instr * dec_instr,
- addr_t read_gva, addr_t read_gpa, addr_t src_addr,
- int (*read_fn)(struct guest_info * core, addr_t guest_addr, void * dst, uint_t length, void * priv_data),
- int (*write_fn)(struct guest_info * core, addr_t guest_addr, void * src, uint_t length, void * priv_data),
- void * priv_data) {
- addr_t em_src_addr = 0;
- addr_t em_dst_addr = 0;
- int src_op_len = 0;
- int dst_op_len = 0;
-
- PrintDebug("Emulating XCHG Read\n");
-
- if (dec_instr->src_operand.type == MEM_OPERAND) {
- if (dec_instr->src_operand.operand != read_gva) {
- PrintError("XCHG: Inconsistency between Pagefault and Instruction Decode XED_ADDR=%p, PF_ADDR=%p\n",
- (void *)dec_instr->src_operand.operand, (void *)read_gva);
- return -1;
- }
-
- em_src_addr = src_addr;
- } else if (dec_instr->src_operand.type == REG_OPERAND) {
- em_src_addr = dec_instr->src_operand.operand;
- } else {
- em_src_addr = (addr_t)&(dec_instr->src_operand.operand);
- }
-
-
-
- if (dec_instr->dst_operand.type == MEM_OPERAND) {
- if (info->shdw_pg_mode == SHADOW_PAGING) {
- if (dec_instr->dst_operand.operand != read_gva) {
- PrintError("XCHG: Inconsistency between Pagefault and Instruction Decode XED_ADDR=%p, PF_ADDR=%p\n",
- (void *)dec_instr->dst_operand.operand, (void *)read_gva);
- return -1;
- }
- } else {
- //check that the operand (GVA) maps to the the faulting GPA
- }
-
- em_dst_addr = src_addr;
- } else if (dec_instr->src_operand.type == REG_OPERAND) {
- em_dst_addr = dec_instr->src_operand.operand;
- } else {
- em_dst_addr = (addr_t)&(dec_instr->src_operand.operand);
- }
-
- dst_op_len = dec_instr->dst_operand.size;
- src_op_len = dec_instr->src_operand.size;
-
- PrintDebug("Dst_Addr = %p, SRC operand = %p\n",
- (void *)em_dst_addr, (void *)em_src_addr);
-
-
- if (read_fn(info, read_gpa, (void *)src_addr, src_op_len, priv_data) != src_op_len) {
- PrintError("Did not fully read hooked data\n");
- return -1;
- }
-
- if (run_op(info, dec_instr->op_type, em_src_addr, em_dst_addr, src_op_len, dst_op_len) == -1) {
- PrintError("Instruction Emulation Failed\n");
- return -1;
- }
-
- if (write_fn(info, read_gpa, (void *)src_addr, dst_op_len, priv_data) != dst_op_len) {
- PrintError("Did not fully write hooked data\n");
- return -1;
- }
-
- info->rip += dec_instr->instr_length;
-
- return dst_op_len;
-}
-
-
-
-
-int v3_emulate_write_op(struct guest_info * info, addr_t write_gva, addr_t write_gpa, addr_t dst_addr,
- int (*write_fn)(struct guest_info * core, addr_t guest_addr, void * src, uint_t length, void * priv_data),
- void * priv_data) {
- struct x86_instr dec_instr;
- uchar_t instr[15];
- int ret = 0;
- addr_t src_addr = 0;
- int src_op_len = 0;
- int dst_op_len = 0;
-
- PrintDebug("Emulating Write for instruction at %p\n", (void *)(addr_t)(info->rip));
- PrintDebug("GVA=%p Dst_Addr=%p\n", (void *)write_gva, (void *)dst_addr);
-
- if (info->mem_mode == PHYSICAL_MEM) {
- ret = v3_read_gpa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
- } else {
- ret = v3_read_gva_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
- }
-
- if (ret == -1) {
- return -1;
- }
-
- if (v3_decode(info, (addr_t)instr, &dec_instr) == -1) {
- PrintError("Decoding Error\n");
- // Kick off single step emulator
- return -1;
- }
-
- /*
- * Instructions needing to be special cased.... *
- */
- if (dec_instr.is_str_op) {
- return emulate_string_write_op(info, &dec_instr, write_gva, write_gpa, dst_addr, write_fn, priv_data);
- } else if (dec_instr.op_type == V3_OP_XCHG) {
- return emulate_xchg_write_op(info, &dec_instr, write_gva, write_gpa, dst_addr, write_fn, priv_data);
- }
-
-
- if (info->shdw_pg_mode == SHADOW_PAGING) {
- if ((dec_instr.dst_operand.type != MEM_OPERAND) ||
- (dec_instr.dst_operand.operand != write_gva)) {
- PrintError("Inconsistency between Pagefault and Instruction Decode XED_ADDR=%p, PF_ADDR=%p\n",
- (void *)dec_instr.dst_operand.operand, (void *)write_gva);
- return -1;
- }
- } else {
- //check that the operand (GVA) maps to the the faulting GPA
- }
-
-
- if (dec_instr.src_operand.type == MEM_OPERAND) {
- if (info->mem_mode == PHYSICAL_MEM) {
- if (v3_gpa_to_hva(info, dec_instr.src_operand.operand, &src_addr) == -1) {
- PrintError("Could not translate write Source (Physical) to host VA\n");
- return -1;
- }
- } else {
- if (v3_gva_to_hva(info, dec_instr.src_operand.operand, &src_addr) == -1) {
- PrintError("Could not translate write Source (Virtual) to host VA\n");
- return -1;
- }
- }
- } else if (dec_instr.src_operand.type == REG_OPERAND) {
- src_addr = dec_instr.src_operand.operand;
- } else {
- src_addr = (addr_t)&(dec_instr.src_operand.operand);
- }
-
- dst_op_len = dec_instr.dst_operand.size;
- src_op_len = dec_instr.src_operand.size;
-
- PrintDebug("Dst_Addr = %p, SRC operand = %p\n",
- (void *)dst_addr, (void *)src_addr);
-
-
- if (run_op(info, dec_instr.op_type, src_addr, dst_addr, src_op_len, dst_op_len) == -1) {
- PrintError("Instruction Emulation Failed\n");
- return -1;
- }
-
- if (write_fn(info, write_gpa, (void *)dst_addr, dst_op_len, priv_data) != dst_op_len) {
- PrintError("Did not fully write hooked data\n");
- return -1;
- }
-
- info->rip += dec_instr.instr_length;
-
- return dst_op_len;
-}
-
-
-int v3_emulate_read_op(struct guest_info * info, addr_t read_gva, addr_t read_gpa, addr_t src_addr,
- int (*read_fn)(struct guest_info * core, addr_t guest_addr, void * dst, uint_t length, void * priv_data),
- int (*write_fn)(struct guest_info * core, addr_t guest_addr, void * src, uint_t length, void * priv_data),
- void * priv_data) {
- struct x86_instr dec_instr;
- uchar_t instr[15];
- int ret = 0;
- addr_t dst_addr = 0;
- int src_op_len = 0;
- int dst_op_len = 0;
-
- PrintDebug("Emulating Read for instruction at %p\n", (void *)(addr_t)(info->rip));
- PrintDebug("GVA=%p\n", (void *)read_gva);
-
- if (info->mem_mode == PHYSICAL_MEM) {
- ret = v3_read_gpa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
- } else {
- ret = v3_read_gva_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
- }
-
- if (ret == -1) {
- PrintError("Could not read instruction for Emulated Read at %p\n", (void *)(addr_t)(info->rip));
- return -1;
- }
-
-
- if (v3_decode(info, (addr_t)instr, &dec_instr) == -1) {
- PrintError("Decoding Error\n");
- // Kick off single step emulator
- return -1;
- }
-
- if (dec_instr.is_str_op) {
- return emulate_string_op(info,&dec_instr,
- read_gva,read_gpa,0,
- 0, 0, 0,
- read_fn,write_fn,
- priv_data);
- } else if (dec_instr.op_type == V3_OP_XCHG) {
- return emulate_xchg_read_op(info, &dec_instr, read_gva, read_gpa, src_addr, read_fn, write_fn, priv_data);
- }
-
- if (info->shdw_pg_mode == SHADOW_PAGING) {
- if ((dec_instr.src_operand.type != MEM_OPERAND) ||
- (dec_instr.src_operand.operand != read_gva)) {
- PrintError("Inconsistency between Pagefault and Instruction Decode XED_ADDR=%p, PF_ADDR=%p operand_type=%d\n",
- (void *)dec_instr.src_operand.operand, (void *)read_gva, dec_instr.src_operand.type);
- return -1;
- }
- } else {
- //check that the operand (GVA) maps to the the faulting GPA
- }
-
- if (dec_instr.dst_operand.type == MEM_OPERAND) {
- if (info->mem_mode == PHYSICAL_MEM) {
- if (v3_gpa_to_hva(info, dec_instr.dst_operand.operand, &dst_addr) == -1) {
- PrintError("Could not translate Read Destination (Physical) to host VA\n");
- return -1;
- }
- } else {
- if (v3_gva_to_hva(info, dec_instr.dst_operand.operand, &dst_addr) == -1) {
- PrintError("Could not translate Read Destination (Virtual) to host VA\n");
- return -1;
- }
- }
- } else if (dec_instr.dst_operand.type == REG_OPERAND) {
- dst_addr = dec_instr.dst_operand.operand;
- } else {
- dst_addr = (addr_t)&(dec_instr.dst_operand.operand);
- }
-
- src_op_len = dec_instr.src_operand.size;
- dst_op_len = dec_instr.dst_operand.size;
-
- PrintDebug("Dst_Addr = %p, SRC Addr = %p\n",
- (void *)dst_addr, (void *)src_addr);
-
- if (read_fn(info, read_gpa, (void *)src_addr, src_op_len, priv_data) != src_op_len) {
- PrintError("Did not fully read hooked data\n");
- return -1;
- }
-
- if (run_op(info, dec_instr.op_type, src_addr, dst_addr, src_op_len, dst_op_len) == -1) {
- PrintError("Instruction Emulation Failed\n");
- return -1;
- }
-
- info->rip += dec_instr.instr_length;
-
- return src_op_len;
-}
-
-
-
-
-
-
-static int run_op(struct guest_info * info, v3_op_type_t op_type, addr_t src_addr, addr_t dst_addr, int src_op_size, int dst_op_size) {
+static int run_op(struct guest_info * info, v3_op_type_t op_type,
+ addr_t src_addr, addr_t dst_addr,
+ int src_op_size, int dst_op_size) {
if (src_op_size == 1) {
- PrintDebug("Executing 8 bit instruction\n");
+ PrintDebug(info->vm_info, info, "Executing 8 bit instruction\n");
switch (op_type) {
case V3_OP_ADC:
break;
default:
- PrintError("Unknown 8 bit instruction\n");
+ PrintError(info->vm_info, info, "Unknown 8 bit instruction\n");
return -1;
}
} else if (src_op_size == 2) {
- PrintDebug("Executing 16 bit instruction\n");
+ PrintDebug(info->vm_info, info, "Executing 16 bit instruction\n");
switch (op_type) {
case V3_OP_ADC:
break;
default:
- PrintError("Unknown 16 bit instruction\n");
+ PrintError(info->vm_info, info, "Unknown 16 bit instruction\n");
return -1;
}
} else if (src_op_size == 4) {
- PrintDebug("Executing 32 bit instruction\n");
+ PrintDebug(info->vm_info, info, "Executing 32 bit instruction\n");
switch (op_type) {
case V3_OP_ADC:
break;
default:
- PrintError("Unknown 32 bit instruction\n");
+ PrintError(info->vm_info, info, "Unknown 32 bit instruction\n");
return -1;
}
#ifdef __V3_64BIT__
} else if (src_op_size == 8) {
- PrintDebug("Executing 64 bit instruction\n");
+ PrintDebug(info->vm_info, info, "Executing 64 bit instruction\n");
switch (op_type) {
case V3_OP_ADC:
break;
default:
- PrintError("Unknown 64 bit instruction\n");
+ PrintError(info->vm_info, info, "Unknown 64 bit instruction\n");
return -1;
}
#endif
} else {
- PrintError("Invalid Operation Size\n");
+ PrintError(info->vm_info, info, "Invalid Operation Size\n");
return -1;
}
return 0;
}
+
+
+
+/* Returns the number of bytes written, or -1 if there is an error */
+static int run_str_op(struct guest_info * core, struct x86_instr * instr,
+ addr_t src_addr, addr_t dst_addr,
+ int op_size, int rep_cnt) {
+
+ addr_t tmp_rcx = rep_cnt;
+ int emulation_length = op_size * rep_cnt;
+ struct rflags * flags_reg = (struct rflags *)&(core->ctrl_regs.rflags);
+
+
+ PrintDebug(core->vm_info, core, "Emulation_len=%d, tmp_rcx=%d\n", emulation_length, (uint_t)tmp_rcx);
+
+
+ if (instr->op_type == V3_OP_MOVS) {
+ if (op_size== 1) {
+ movs8((addr_t *)&dst_addr, &src_addr, &tmp_rcx, (addr_t *)&(core->ctrl_regs.rflags));
+ } else if (op_size == 2) {
+ movs16((addr_t *)&dst_addr, &src_addr, &tmp_rcx, (addr_t *)&(core->ctrl_regs.rflags));
+ } else if (op_size == 4) {
+ movs32((addr_t *)&dst_addr, &src_addr, &tmp_rcx, (addr_t *)&(core->ctrl_regs.rflags));
+#ifdef __V3_64BIT__
+ } else if (op_size == 8) {
+ movs64((addr_t *)&dst_addr, &src_addr, &tmp_rcx, (addr_t *)&(core->ctrl_regs.rflags));
+#endif
+ } else {
+ PrintError(core->vm_info, core, "Invalid operand length\n");
+ return -1;
+ }
+
+ if (flags_reg->df == 0) {
+ core->vm_regs.rdi += emulation_length;
+ core->vm_regs.rsi += emulation_length;
+ } else {
+ core->vm_regs.rdi -= emulation_length;
+ core->vm_regs.rsi -= emulation_length;
+ }
+
+ // RCX is only modified if the rep prefix is present
+ if (instr->prefixes.rep == 1) {
+ core->vm_regs.rcx -= rep_cnt;
+ }
+
+ } else if (instr->op_type == V3_OP_STOS) {
+ if (op_size == 1) {
+ stos8((addr_t *)&dst_addr, (addr_t *)&(core->vm_regs.rax), &tmp_rcx, (addr_t *)&(core->ctrl_regs.rflags));
+ } else if (op_size == 2) {
+ stos16((addr_t *)&dst_addr, (addr_t *)&(core->vm_regs.rax), &tmp_rcx, (addr_t *)&(core->ctrl_regs.rflags));
+ } else if (op_size == 4) {
+ stos32((addr_t *)&dst_addr, (addr_t *)&(core->vm_regs.rax), &tmp_rcx, (addr_t *)&(core->ctrl_regs.rflags));
+#ifdef __V3_64BIT__
+ } else if (op_size == 8) {
+ stos64((addr_t *)&dst_addr, (addr_t *)&(core->vm_regs.rax), &tmp_rcx, (addr_t *)&(core->ctrl_regs.rflags));
+#endif
+ } else {
+ PrintError(core->vm_info, core, "Invalid operand length\n");
+ return -1;
+ }
+
+
+
+ if (flags_reg->df == 0) {
+ core->vm_regs.rdi += emulation_length;
+ } else {
+ core->vm_regs.rdi -= emulation_length;
+ }
+
+ // RCX is only modified if the rep prefix is present
+ if (instr->prefixes.rep == 1) {
+ core->vm_regs.rcx -= rep_cnt;
+ }
+ } else {
+ PrintError(core->vm_info, core, "Unimplemented String operation\n");
+ return -1;
+ }
+
+ return emulation_length;
+}
+
+
+
+int v3_emulate(struct guest_info * core, struct x86_instr * instr,
+ int mem_op_size, addr_t mem_hva_src, addr_t mem_hva_dst) {
+
+ addr_t src_hva = 0;
+ addr_t dst_hva = 0;
+
+
+ if (instr->src_operand.type == MEM_OPERAND) {
+ src_hva = mem_hva_src;
+ } else if (instr->src_operand.type == REG_OPERAND) {
+ src_hva = instr->src_operand.operand;
+ } else {
+ src_hva = (addr_t)&(instr->src_operand.operand);
+ }
+
+ if (instr->dst_operand.type == MEM_OPERAND) {
+ dst_hva = mem_hva_dst;
+ } else if (instr->dst_operand.type == REG_OPERAND) {
+ dst_hva = instr->dst_operand.operand;
+ } else {
+ dst_hva = (addr_t)&(instr->dst_operand.operand);
+ }
+
+
+ if (instr->is_str_op == 0) {
+ int src_op_len = instr->src_operand.size;
+ int dst_op_len = instr->dst_operand.size;
+
+ run_op(core, instr->op_type, src_hva, dst_hva, src_op_len, dst_op_len);
+
+ return dst_op_len;
+ } else {
+ // String Operation
+ int rep_cnt = 0;
+
+ /* Both src and dst operand sizes should be identical */
+ rep_cnt = mem_op_size / instr->src_operand.size;
+
+ return run_str_op(core, instr, src_hva, dst_hva, instr->src_operand.size, rep_cnt);
+ }
+
+
+ return -1;
+}
