#include <palacios/vmm_mem_hook.h>
#include <palacios/vmm_emulator.h>
#include <palacios/vm_guest_mem.h>
+#include <palacios/vmm_hashtable.h>
+#include <palacios/vmm_decoder.h>
struct mem_hook {
int (*read)(struct guest_info * core, addr_t guest_addr, void * dst, uint_t length, void * priv_data);
// Called when data is written to a memory page
int (*write)(struct guest_info * core, addr_t guest_addr, void * src, uint_t length, void * priv_data);
+ // Called when memory page is accessed
+ int (*access)(struct guest_info *core, addr_t guest_va, addr_t guest_pa, struct v3_mem_region *region, pf_error_t access_info, void *priv_data);
void * priv_data;
- addr_t hook_hva;
-
+ struct v3_mem_region * region;
+
+ struct list_head hook_node;
};
+static int free_hook(struct v3_vm_info * vm, struct mem_hook * hook);
+
+static uint_t mem_hash_fn(addr_t key) {
+ return v3_hash_long(key, sizeof(void *) * 8);
+}
+
+static int mem_eq_fn(addr_t key1, addr_t key2) {
+ return (key1 == key2);
+}
+
int v3_init_mem_hooks(struct v3_vm_info * vm) {
+ void *temp;
+
struct v3_mem_hooks * hooks = &(vm->mem_hooks);
- hooks->hook_hvas = V3_VAddr(V3_AllocPages(vm->num_cores));
+ temp = V3_AllocPages(vm->num_cores);
+
+ if (!temp) {
+ PrintError(vm, VCORE_NONE, "Cannot allocate space for mem hooks\n");
+ return -1;
+ }
+
+ hooks->hook_hvas_1 = V3_VAddr(temp);
+
+ temp = V3_AllocPages(vm->num_cores);
+
+ if (!temp) {
+ PrintError(vm, VCORE_NONE,"Cannot allocate space for mem hooks\n");
+ V3_FreePages(hooks->hook_hvas_1,vm->num_cores);
+ return -1;
+ }
+
+ hooks->hook_hvas_2 = V3_VAddr(temp);
INIT_LIST_HEAD(&(hooks->hook_list));
+ hooks->reg_table = v3_create_htable(0, mem_hash_fn, mem_eq_fn);
+
+ hooks->inited=1;
+
return 0;
}
+// We'll assume the actual hooks were either already cleared,
+// or will be cleared by the memory map
+int v3_deinit_mem_hooks(struct v3_vm_info * vm) {
+ struct v3_mem_hooks * hooks = &(vm->mem_hooks);
+ struct mem_hook * hook = NULL;
+ struct mem_hook * tmp = NULL;
-static int handle_mem_hook(struct guest_info * info, addr_t guest_va, addr_t guest_pa,
- struct v3_mem_region * reg, pf_error_t access_info) {
- struct mem_hook * hook = reg->priv_data;
- addr_t op_addr = 0;
+ if (!hooks->inited) {
+ return 0;
+ }
- if (reg->flags.alloced == 0) {
- op_addr = hook->hook_hva;
+ // This is nasty...
+ // We delete the hook info but leave its memory region intact
+ // We rely on the memory map to clean up any orphaned regions as a result of this
+ // This needs to be fixed at some point...
+ list_for_each_entry_safe(hook, tmp, &(hooks->hook_list), hook_node) {
+ free_hook(vm, hook);
+ }
+
+
+ v3_free_htable(hooks->reg_table, 0, 0);
+
+ V3_FreePages(V3_PAddr(hooks->hook_hvas_1), vm->num_cores);
+ V3_FreePages(V3_PAddr(hooks->hook_hvas_2), vm->num_cores);
+
+ return 0;
+}
+
+
+
+static inline int get_op_length(struct x86_instr * instr, struct x86_operand * operand, addr_t tgt_addr) {
+
+ if (instr->is_str_op) {
+ if ((instr->str_op_length * operand->size) < (0x1000 - PAGE_OFFSET_4KB(tgt_addr))) {
+ return (instr->str_op_length * operand->size);
+ } else {
+ return (0x1000 - PAGE_OFFSET_4KB(tgt_addr));
+ }
} else {
- if (v3_gpa_to_hva(info, guest_pa, &op_addr) == -1) {
- PrintError("Could not translate hook address (%p)\n", (void *)guest_pa);
+ return instr->src_operand.size;
+ }
+
+}
+
+
+
+static int handle_mem_hook(struct guest_info * core, addr_t guest_va, addr_t guest_pa,
+ struct v3_mem_region * reg, pf_error_t access_info) {
+ struct v3_mem_hooks * hooks = &(core->vm_info->mem_hooks);
+ struct x86_instr instr;
+ void * instr_ptr = NULL;
+ int bytes_emulated = 0;
+ int mem_op_size = 0;
+ int ret = 0;
+
+ struct mem_hook * src_hook = NULL;
+ addr_t src_mem_op_hva = 0;
+ addr_t src_mem_op_gpa = 0;
+ int src_req_size = -1;
+
+ struct mem_hook * dst_hook = NULL;
+ addr_t dst_mem_op_hva = 0;
+ addr_t dst_mem_op_gpa = 0;
+ int dst_req_size = -1;
+
+
+ struct mem_hook *access_hook = NULL;
+
+ // Let access hooks take priority
+ access_hook = (struct mem_hook *) reg->priv_data;
+ if (access_hook && access_hook->access) {
+ return access_hook->access(core, guest_va, guest_pa, reg, access_info, access_hook->priv_data);
+ }
+
+
+ /* Find and decode hooked instruction */
+ if (core->mem_mode == PHYSICAL_MEM) {
+ ret = v3_gpa_to_hva(core, get_addr_linear(core, core->rip, &(core->segments.cs)), (addr_t *)&instr_ptr);
+ } else {
+ ret = v3_gva_to_hva(core, get_addr_linear(core, core->rip, &(core->segments.cs)), (addr_t *)&instr_ptr);
+ }
+
+ if (ret == -1) {
+ PrintError(core->vm_info, core, "Could not translate Instruction Address (%p)\n", (void *)(addr_t)core->rip);
+ return -1;
+ }
+
+ if (v3_decode(core, (addr_t)instr_ptr, &instr) == -1) {
+ PrintError(core->vm_info, core, "Decoding Error\n");
+ return -1;
+ }
+
+
+
+ // Test source operand, if it's memory we need to do some translations, and handle a possible hook
+ if (instr.src_operand.type == MEM_OPERAND) {
+ struct v3_mem_region * src_reg = NULL;
+
+ if (core->mem_mode == PHYSICAL_MEM) {
+ src_mem_op_gpa = instr.src_operand.operand;
+ } else {
+ if (v3_gva_to_gpa(core, instr.src_operand.operand, &src_mem_op_gpa) == -1) {
+ pf_error_t error = access_info;
+
+ error.present = 0;
+ v3_inject_guest_pf(core, instr.src_operand.operand, error);
+
+ return 0;
+ }
+ }
+
+ if ((src_mem_op_gpa >= reg->guest_start) &&
+ (src_mem_op_gpa < reg->guest_end)) {
+ // Src address corresponds to faulted region
+ src_reg = reg;
+ } else {
+ // Note that this should only trigger for string operations
+ src_reg = v3_get_mem_region(core->vm_info, core->vcpu_id, src_mem_op_gpa);
+ }
+
+ if (src_reg == NULL) {
+ PrintError(core->vm_info, core, "Error finding Source region (addr=%p)\n", (void *)src_mem_op_gpa);
return -1;
}
+
+ src_hook = (struct mem_hook *)v3_htable_search(hooks->reg_table, (addr_t)src_reg);
+
+ // We don't check whether the region is a hook here because it doesn't yet matter.
+ // These hva calculations will be true regardless
+ if (src_reg->flags.alloced == 0) {
+ src_mem_op_hva = (addr_t)(hooks->hook_hvas_1 + (PAGE_SIZE * core->vcpu_id));
+ } else {
+ // We already have the region so we can do the conversion ourselves
+ src_mem_op_hva = (addr_t)V3_VAddr((void *)((src_mem_op_gpa - src_reg->guest_start) + src_reg->host_addr));
+ }
+
+ src_req_size = get_op_length(&instr, &(instr.src_operand), src_mem_op_hva);
}
-
- if (access_info.write == 1) {
- // Write Operation
+ // Now do the same translation / hook handling for the second operand
+ if (instr.dst_operand.type == MEM_OPERAND) {
+ struct v3_mem_region * dst_reg = NULL;
+
+
+ if (core->mem_mode == PHYSICAL_MEM) {
+ dst_mem_op_gpa = instr.dst_operand.operand;
+ } else {
+ if (v3_gva_to_gpa(core, instr.dst_operand.operand, &dst_mem_op_gpa) == -1) {
+ pf_error_t error = access_info;
+
+ error.present = 0;
+ v3_inject_guest_pf(core, instr.dst_operand.operand, error);
+
+ return 0;
+ }
+ }
+
+ if ((dst_mem_op_gpa >= reg->guest_start) &&
+ (dst_mem_op_gpa < reg->guest_end)) {
+ // Dst address corresponds to faulted region
+ dst_reg = reg;
+ } else {
+ // Note that this should only trigger for string operations
+ dst_reg = v3_get_mem_region(core->vm_info, core->vcpu_id, dst_mem_op_gpa);
+ }
- if (v3_emulate_write_op(info, guest_va, guest_pa, op_addr,
- hook->write, hook->priv_data) == -1) {
- PrintError("Write Full Hook emulation failed\n");
+ if (dst_reg == NULL) {
+ PrintError(core->vm_info, core, "Error finding Source region (addr=%p)\n", (void *)dst_mem_op_gpa);
return -1;
}
- } else {
- // Read Operation
- if (reg->flags.read == 1) {
- PrintError("Tried to emulate read for a guest Readable page\n");
+ dst_hook = (struct mem_hook *)v3_htable_search(hooks->reg_table, (addr_t)dst_reg);
+
+ // We don't check whether the region is a hook here because it doesn't yet matter.
+ // These hva calculations will be true regardless
+ if (dst_reg->flags.alloced == 0) {
+ dst_mem_op_hva = (addr_t)(hooks->hook_hvas_2 + (PAGE_SIZE * core->vcpu_id));
+ } else {
+ // We already have the region so we can do the conversion ourselves
+ dst_mem_op_hva = (addr_t)V3_VAddr((void *)((dst_mem_op_gpa - dst_reg->guest_start) + dst_reg->host_addr));
+ }
+
+ dst_req_size = get_op_length(&instr, &(instr.dst_operand), dst_mem_op_hva);
+ }
+
+
+ mem_op_size = ((uint_t)src_req_size < (uint_t)dst_req_size) ? src_req_size : dst_req_size;
+
+ if (mem_op_size == -1) {
+ PrintError(core->vm_info, core, "Error: Did not detect any memory operands...\n");
+ return -1;
+ }
+
+
+ /* Now handle the hooks if necessary */
+ if ( (src_hook != NULL) && (src_hook->read != NULL) &&
+ (instr.src_operand.read == 1) ) {
+
+ // Read in data from hook
+
+ if (src_hook->read(core, src_mem_op_gpa, (void *)src_mem_op_hva, mem_op_size, src_hook->priv_data) == -1) {
+ PrintError(core->vm_info, core, "Read hook error at src_mem_op_gpa=%p\n", (void *)src_mem_op_gpa);
return -1;
}
+ }
- if (v3_emulate_read_op(info, guest_va, guest_pa, op_addr,
- hook->read, hook->write,
- hook->priv_data) == -1) {
- PrintError("Read Full Hook emulation failed\n");
+ if ( (dst_hook != NULL) && (dst_hook->read != NULL) &&
+ (instr.dst_operand.read == 1) ) {
+
+ // Read in data from hook
+
+ if (dst_hook->read(core, dst_mem_op_gpa, (void *)dst_mem_op_hva, mem_op_size, dst_hook->priv_data) == -1) {
+ PrintError(core->vm_info, core, "Read hook error at dst_mem_op_gpa=%p\n", (void *)dst_mem_op_gpa);
return -1;
}
+ }
+
+ bytes_emulated = v3_emulate(core, &instr, mem_op_size, src_mem_op_hva, dst_mem_op_hva);
+ if (bytes_emulated == -1) {
+ PrintError(core->vm_info, core, "Error emulating instruction\n");
+ return -1;
+ }
+
+
+ if ( (src_hook != NULL) && (src_hook->write != NULL) &&
+ (instr.src_operand.write == 1) ) {
+
+ if (src_hook->write(core, src_mem_op_gpa, (void *)src_mem_op_hva, bytes_emulated, src_hook->priv_data) == -1) {
+ PrintError(core->vm_info, core, "Write hook error at src_mem_op_gpa=%p\n", (void *)src_mem_op_gpa);
+ return -1;
+ }
+
+ }
+
+
+ if ( (dst_hook != NULL) && (dst_hook->write != NULL) &&
+ (instr.dst_operand.write == 1) ) {
+
+ if (dst_hook->write(core, dst_mem_op_gpa, (void *)dst_mem_op_hva, bytes_emulated, dst_hook->priv_data) == -1) {
+ PrintError(core->vm_info, core, "Write hook error at dst_mem_op_gpa=%p\n", (void *)dst_mem_op_gpa);
+ return -1;
+ }
+ }
+
+
+ if (instr.is_str_op == 0) {
+ core->rip += instr.instr_length;
}
-
int v3_hook_write_mem(struct v3_vm_info * vm, uint16_t core_id,
addr_t guest_addr_start, addr_t guest_addr_end, addr_t host_addr,
int (*write)(struct guest_info * core, addr_t guest_addr, void * src, uint_t length, void * priv_data),
void * priv_data) {
struct v3_mem_region * entry = NULL;
struct mem_hook * hook = V3_Malloc(sizeof(struct mem_hook));
- // struct v3_mem_hooks * hooks = &(vm->mem_hooks);
+ struct v3_mem_hooks * hooks = &(vm->mem_hooks);
+
+ if (!hook) {
+ PrintError(vm, VCORE_NONE, "Cannot allocate in hooking memory for full access\n");
+ return -1;
+ }
memset(hook, 0, sizeof(struct mem_hook));
hook->write = write;
hook->read = NULL;
hook->priv_data = priv_data;
- hook->hook_hva = (addr_t)V3_VAddr((void *)host_addr);
entry = v3_create_mem_region(vm, core_id, guest_addr_start, guest_addr_end);
-
+
+ if (!entry) {
+ PrintError(vm, VCORE_NONE, "Cannot allocate a memory region\n");
+ V3_Free(hook);
+ return -1;
+ }
+
+ hook->region = entry;
+
entry->host_addr = host_addr;
entry->unhandled = handle_mem_hook;
entry->priv_data = hook;
entry->flags.alloced = 1;
if (v3_insert_mem_region(vm, entry) == -1) {
+ PrintError(vm, VCORE_NONE, "Cannot insert memory region\n");
V3_Free(entry);
V3_Free(hook);
return -1;
}
+ v3_htable_insert(hooks->reg_table, (addr_t)entry, (addr_t)hook);
+ list_add(&(hook->hook_node), &(hooks->hook_list));
+
return 0;
}
struct mem_hook * hook = V3_Malloc(sizeof(struct mem_hook));
struct v3_mem_hooks * hooks = &(vm->mem_hooks);
+ if (!hook) {
+ PrintError(vm, VCORE_NONE, "Cannot allocate in hooking memory for writing\n");
+ return -1;
+ }
+
memset(hook, 0, sizeof(struct mem_hook));
hook->write = write;
hook->read = read;
hook->priv_data = priv_data;
- hook->hook_hva = (addr_t)hooks->hook_hvas + (PAGE_SIZE_4KB * core_id);
entry = v3_create_mem_region(vm, core_id, guest_addr_start, guest_addr_end);
+ if (!entry) {
+ PrintError(vm, VCORE_NONE, "Cannot create memory region\n");
+ V3_Free(hook);
+ return -1;
+ }
+
+ hook->region = entry;
+
+ entry->unhandled = handle_mem_hook;
+ entry->priv_data = hook;
+
+ if (v3_insert_mem_region(vm, entry)) {
+ PrintError(vm, VCORE_NONE, "Cannot insert memory region\n");
+ V3_Free(entry);
+ V3_Free(hook);
+ return -1;
+ }
+
+ list_add(&(hook->hook_node), &(hooks->hook_list));
+ v3_htable_insert(hooks->reg_table, (addr_t)entry, (addr_t)hook);
+
+
+ return 0;
+}
+
+
+int v3_hook_access_mem(struct v3_vm_info * vm, uint16_t core_id,
+ addr_t guest_addr_start, addr_t guest_addr_end,
+ int (*access)(struct guest_info * core,
+ addr_t guest_va,
+ addr_t guest_pa,
+ struct v3_mem_region *reg,
+ pf_error_t access_info,
+ void *priv_data),
+ void * priv_data)
+{
+
+ struct v3_mem_region * entry = NULL;
+ struct mem_hook * hook = V3_Malloc(sizeof(struct mem_hook));
+ struct v3_mem_hooks * hooks = &(vm->mem_hooks);
+
+ if (!hook) {
+ PrintError(vm, VCORE_NONE,"Cannot allocate in hooking memory for access\n");
+ return -1;
+ }
+
+ memset(hook, 0, sizeof(struct mem_hook));
+
+ hook->access = access;
+ hook->priv_data = priv_data;
+
+ entry = v3_create_mem_region(vm, core_id, guest_addr_start, guest_addr_end);
+
+ if (!entry) {
+ PrintError(vm, VCORE_NONE, "Cannot create memory region\n");
+ V3_Free(hook);
+ return -1;
+ }
+
+ hook->region = entry;
+
entry->unhandled = handle_mem_hook;
entry->priv_data = hook;
if (v3_insert_mem_region(vm, entry)) {
+ PrintError(vm, VCORE_NONE, "Cannot insert memory region\n");
V3_Free(entry);
V3_Free(hook);
return -1;
}
+ list_add(&(hook->hook_node), &(hooks->hook_list));
+ v3_htable_insert(hooks->reg_table, (addr_t)entry, (addr_t)hook);
+
return 0;
}
+static int free_hook(struct v3_vm_info * vm, struct mem_hook * hook) {
+ v3_delete_mem_region(vm, hook->region);
+ list_del(&(hook->hook_node));
+
+ V3_Free(hook);
+
+ return 0;
+}
+
// This will unhook the memory hook registered at start address
// We do not support unhooking subregions
int v3_unhook_mem(struct v3_vm_info * vm, uint16_t core_id, addr_t guest_addr_start) {
struct v3_mem_region * reg = v3_get_mem_region(vm, core_id, guest_addr_start);
- struct mem_hook * hook = reg->priv_data;
+ struct v3_mem_hooks * hooks = &(vm->mem_hooks);
+ struct mem_hook * hook = NULL;
- V3_Free(hook);
-
- v3_delete_mem_region(vm, reg);
+ if (reg == NULL) {
+ PrintError(vm, VCORE_NONE, "Could not find region at %p\n", (void *)guest_addr_start);
+ return -1;
+ }
+
+ hook = reg->priv_data;
+
+ if (hook == NULL) {
+ PrintError(vm, VCORE_NONE, "Trying to unhook region that is not a hook at %p\n", (void *)guest_addr_start);
+ return -1;
+ }
+
+
+ free_hook(vm, hook);
+
+ v3_htable_remove(hooks->reg_table, (addr_t)reg, 0);
return 0;
}
