2 * This file is part of the Palacios Virtual Machine Monitor developed
3 * by the V3VEE Project with funding from the United States National
4 * Science Foundation and the Department of Energy.
6 * The V3VEE Project is a joint project between Northwestern University
7 * and the University of New Mexico. You can find out more at
10 * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu>
11 * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org>
12 * All rights reserved.
14 * Author: Jack Lange <jarusl@cs.northwestern.edu>
16 * This is free software. You are permitted to use,
17 * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
20 #include <palacios/vmm.h>
21 #include <palacios/vm_guest.h>
22 #include <palacios/vmm_mem_hook.h>
23 #include <palacios/vmm_emulator.h>
24 #include <palacios/vm_guest_mem.h>
25 #include <palacios/vmm_hashtable.h>
26 #include <palacios/vmm_decoder.h>
30 // Called when data is read from a memory page
31 int (*read)(struct guest_info * core, addr_t guest_addr, void * dst, uint_t length, void * priv_data);
32 // Called when data is written to a memory page
33 int (*write)(struct guest_info * core, addr_t guest_addr, void * src, uint_t length, void * priv_data);
36 struct v3_mem_region * region;
39 struct list_head hook_node;
44 static int free_hook(struct v3_vm_info * vm, struct mem_hook * hook);
46 static uint_t mem_hash_fn(addr_t key) {
47 return v3_hash_long(key, sizeof(void *) * 8);
50 static int mem_eq_fn(addr_t key1, addr_t key2) {
51 return (key1 == key2);
54 int v3_init_mem_hooks(struct v3_vm_info * vm) {
55 struct v3_mem_hooks * hooks = &(vm->mem_hooks);
57 hooks->hook_hvas_1 = V3_VAddr(V3_AllocPages(vm->num_cores));
58 hooks->hook_hvas_2 = V3_VAddr(V3_AllocPages(vm->num_cores));
60 INIT_LIST_HEAD(&(hooks->hook_list));
62 hooks->reg_table = v3_create_htable(0, mem_hash_fn, mem_eq_fn);
68 // We'll assume the actual hooks were either already cleared,
69 // or will be cleared by the memory map
70 int v3_deinit_mem_hooks(struct v3_vm_info * vm) {
71 struct v3_mem_hooks * hooks = &(vm->mem_hooks);
72 struct mem_hook * hook = NULL;
73 struct mem_hook * tmp = NULL;
77 // We delete the hook info but leave its memory region intact
78 // We rely on the memory map to clean up any orphaned regions as a result of this
79 // This needs to be fixed at some point...
80 list_for_each_entry_safe(hook, tmp, &(hooks->hook_list), hook_node) {
85 v3_free_htable(hooks->reg_table, 0, 0);
87 V3_FreePages(V3_PAddr(hooks->hook_hvas_1), vm->num_cores);
88 V3_FreePages(V3_PAddr(hooks->hook_hvas_2), vm->num_cores);
95 static inline int get_op_length(struct x86_instr * instr, struct x86_operand * operand, addr_t tgt_addr) {
97 if (instr->is_str_op) {
98 if ((instr->str_op_length * operand->size) < (0x1000 - PAGE_OFFSET_4KB(tgt_addr))) {
99 return (instr->str_op_length * operand->size);
101 return (0x1000 - PAGE_OFFSET_4KB(tgt_addr));
104 return instr->src_operand.size;
111 static int handle_mem_hook(struct guest_info * core, addr_t guest_va, addr_t guest_pa,
112 struct v3_mem_region * reg, pf_error_t access_info) {
113 struct v3_mem_hooks * hooks = &(core->vm_info->mem_hooks);
114 struct x86_instr instr;
115 void * instr_ptr = NULL;
116 int bytes_emulated = 0;
120 struct mem_hook * src_hook = NULL;
121 addr_t src_mem_op_hva = 0;
122 addr_t src_mem_op_gpa = 0;
123 int src_req_size = -1;
125 struct mem_hook * dst_hook = NULL;
126 addr_t dst_mem_op_hva = 0;
127 addr_t dst_mem_op_gpa = 0;
128 int dst_req_size = -1;
130 /* Find and decode hooked instruction */
131 if (core->mem_mode == PHYSICAL_MEM) {
132 ret = v3_gpa_to_hva(core, get_addr_linear(core, core->rip, &(core->segments.cs)), (addr_t *)&instr_ptr);
134 ret = v3_gva_to_hva(core, get_addr_linear(core, core->rip, &(core->segments.cs)), (addr_t *)&instr_ptr);
138 PrintError("Could not translate Instruction Address (%p)\n", (void *)core->rip);
142 if (v3_decode(core, (addr_t)instr_ptr, &instr) == -1) {
143 PrintError("Decoding Error\n");
149 // Test source operand, if it's memory we need to do some translations, and handle a possible hook
150 if (instr.src_operand.type == MEM_OPERAND) {
151 struct v3_mem_region * src_reg = NULL;
153 if (core->mem_mode == PHYSICAL_MEM) {
154 src_mem_op_gpa = instr.src_operand.operand;
156 if (v3_gva_to_gpa(core, instr.src_operand.operand, &src_mem_op_gpa) == -1) {
157 pf_error_t error = access_info;
160 v3_inject_guest_pf(core, instr.src_operand.operand, error);
166 if ((src_mem_op_gpa >= reg->guest_start) &&
167 (src_mem_op_gpa < reg->guest_end)) {
168 // Src address corresponds to faulted region
171 // Note that this should only trigger for string operations
172 src_reg = v3_get_mem_region(core->vm_info, core->cpu_id, src_mem_op_gpa);
175 if (src_reg == NULL) {
176 PrintError("Error finding Source region (addr=%p)\n", (void *)src_mem_op_gpa);
180 src_hook = (struct mem_hook *)v3_htable_search(hooks->reg_table, (addr_t)src_reg);
182 // We don't check whether the region is a hook here because it doesn't yet matter.
183 // These hva calculations will be true regardless
184 if (src_reg->flags.alloced == 0) {
185 src_mem_op_hva = (addr_t)(hooks->hook_hvas_1 + (PAGE_SIZE * core->cpu_id));
187 // We already have the region so we can do the conversion ourselves
188 src_mem_op_hva = (addr_t)V3_VAddr((void *)((src_mem_op_gpa - src_reg->guest_start) + src_reg->host_addr));
191 src_req_size = get_op_length(&instr, &(instr.src_operand), src_mem_op_hva);
194 // Now do the same translation / hook handling for the second operand
195 if (instr.dst_operand.type == MEM_OPERAND) {
196 struct v3_mem_region * dst_reg = NULL;
199 if (core->mem_mode == PHYSICAL_MEM) {
200 dst_mem_op_gpa = instr.dst_operand.operand;
202 if (v3_gva_to_gpa(core, instr.dst_operand.operand, &dst_mem_op_gpa) == -1) {
203 pf_error_t error = access_info;
206 v3_inject_guest_pf(core, instr.dst_operand.operand, error);
212 if ((dst_mem_op_gpa >= reg->guest_start) &&
213 (dst_mem_op_gpa < reg->guest_end)) {
214 // Dst address corresponds to faulted region
217 // Note that this should only trigger for string operations
218 dst_reg = v3_get_mem_region(core->vm_info, core->cpu_id, dst_mem_op_gpa);
221 if (dst_reg == NULL) {
222 PrintError("Error finding Source region (addr=%p)\n", (void *)dst_mem_op_gpa);
226 dst_hook = (struct mem_hook *)v3_htable_search(hooks->reg_table, (addr_t)dst_reg);
228 // We don't check whether the region is a hook here because it doesn't yet matter.
229 // These hva calculations will be true regardless
230 if (dst_reg->flags.alloced == 0) {
231 dst_mem_op_hva = (addr_t)(hooks->hook_hvas_2 + (PAGE_SIZE * core->cpu_id));
233 // We already have the region so we can do the conversion ourselves
234 dst_mem_op_hva = (addr_t)V3_VAddr((void *)((dst_mem_op_gpa - dst_reg->guest_start) + dst_reg->host_addr));
237 dst_req_size = get_op_length(&instr, &(instr.dst_operand), dst_mem_op_hva);
241 mem_op_size = ((uint_t)src_req_size < (uint_t)dst_req_size) ? src_req_size : dst_req_size;
244 /* Now handle the hooks if necessary */
245 if ( (src_hook != NULL) && (src_hook->read != NULL) &&
246 (instr.src_operand.read == 1) ) {
248 // Read in data from hook
250 if (src_hook->read(core, src_mem_op_gpa, (void *)src_mem_op_hva, mem_op_size, src_hook->priv_data) == -1) {
251 PrintError("Read hook error at src_mem_op_gpa=%p\n", (void *)src_mem_op_gpa);
256 if ( (dst_hook != NULL) && (dst_hook->read != NULL) &&
257 (instr.dst_operand.read == 1) ) {
259 // Read in data from hook
261 if (dst_hook->read(core, dst_mem_op_gpa, (void *)dst_mem_op_hva, mem_op_size, dst_hook->priv_data) == -1) {
262 PrintError("Read hook error at dst_mem_op_gpa=%p\n", (void *)dst_mem_op_gpa);
267 bytes_emulated = v3_emulate(core, &instr, mem_op_size, src_mem_op_hva, dst_mem_op_hva);
269 if (bytes_emulated == -1) {
270 PrintError("Error emulating instruction\n");
275 if ( (src_hook != NULL) && (src_hook->write != NULL) &&
276 (instr.src_operand.write == 1) ) {
278 if (src_hook->write(core, src_mem_op_gpa, (void *)src_mem_op_hva, bytes_emulated, src_hook->priv_data) == -1) {
279 PrintError("Write hook error at src_mem_op_gpa=%p\n", (void *)src_mem_op_gpa);
286 if ( (dst_hook != NULL) && (dst_hook->write != NULL) &&
287 (instr.dst_operand.write == 1) ) {
289 if (dst_hook->write(core, dst_mem_op_gpa, (void *)dst_mem_op_hva, bytes_emulated, dst_hook->priv_data) == -1) {
290 PrintError("Write hook error at dst_mem_op_gpa=%p\n", (void *)dst_mem_op_gpa);
296 if (instr.is_str_op == 0) {
297 core->rip += instr.instr_length;
307 int v3_hook_write_mem(struct v3_vm_info * vm, uint16_t core_id,
308 addr_t guest_addr_start, addr_t guest_addr_end, addr_t host_addr,
309 int (*write)(struct guest_info * core, addr_t guest_addr, void * src, uint_t length, void * priv_data),
311 struct v3_mem_region * entry = NULL;
312 struct mem_hook * hook = V3_Malloc(sizeof(struct mem_hook));
313 struct v3_mem_hooks * hooks = &(vm->mem_hooks);
315 memset(hook, 0, sizeof(struct mem_hook));
319 hook->priv_data = priv_data;
321 entry = v3_create_mem_region(vm, core_id, guest_addr_start, guest_addr_end);
323 hook->region = entry;
325 entry->host_addr = host_addr;
326 entry->unhandled = handle_mem_hook;
327 entry->priv_data = hook;
329 entry->flags.read = 1;
330 entry->flags.exec = 1;
331 entry->flags.alloced = 1;
333 if (v3_insert_mem_region(vm, entry) == -1) {
339 v3_htable_insert(hooks->reg_table, (addr_t)entry, (addr_t)hook);
340 list_add(&(hook->hook_node), &(hooks->hook_list));
347 int v3_hook_full_mem(struct v3_vm_info * vm, uint16_t core_id,
348 addr_t guest_addr_start, addr_t guest_addr_end,
349 int (*read)(struct guest_info * core, addr_t guest_addr, void * dst, uint_t length, void * priv_data),
350 int (*write)(struct guest_info * core, addr_t guest_addr, void * src, uint_t length, void * priv_data),
353 struct v3_mem_region * entry = NULL;
354 struct mem_hook * hook = V3_Malloc(sizeof(struct mem_hook));
355 struct v3_mem_hooks * hooks = &(vm->mem_hooks);
357 memset(hook, 0, sizeof(struct mem_hook));
361 hook->priv_data = priv_data;
363 entry = v3_create_mem_region(vm, core_id, guest_addr_start, guest_addr_end);
364 hook->region = entry;
366 entry->unhandled = handle_mem_hook;
367 entry->priv_data = hook;
369 if (v3_insert_mem_region(vm, entry)) {
375 list_add(&(hook->hook_node), &(hooks->hook_list));
376 v3_htable_insert(hooks->reg_table, (addr_t)entry, (addr_t)hook);
383 static int free_hook(struct v3_vm_info * vm, struct mem_hook * hook) {
384 v3_delete_mem_region(vm, hook->region);
385 list_del(&(hook->hook_node));
393 // This will unhook the memory hook registered at start address
394 // We do not support unhooking subregions
395 int v3_unhook_mem(struct v3_vm_info * vm, uint16_t core_id, addr_t guest_addr_start) {
396 struct v3_mem_region * reg = v3_get_mem_region(vm, core_id, guest_addr_start);
397 struct mem_hook * hook = reg->priv_data;