}
-// We don't need to virtualize CR4, all we need is to detect the activation of PAE
+//return guest cr4 - shadow PAE is always on
int v3_handle_cr4_read(struct guest_info * info) {
- PrintError(info->vm_info, info, "CR4 Read not handled\n");
- // Do nothing...
+ uchar_t instr[15];
+ int ret;
+ struct x86_instr dec_instr;
+
+ 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 (v3_decode(info, (addr_t)instr, &dec_instr) == -1) {
+ PrintError(info->vm_info, info, "Could not decode instruction\n");
+ return -1;
+ }
+ if (dec_instr.op_type != V3_OP_MOVCR2) {
+ PrintError(info->vm_info, info, "Invalid opcode in read CR4\n");
+ return -1;
+ }
+
+ if (info->shdw_pg_mode == SHADOW_PAGING) {
+
+ if ((v3_get_vm_cpu_mode(info) == LONG) ||
+ (v3_get_vm_cpu_mode(info) == LONG_32_COMPAT)) {
+ struct cr4_64 * dst_reg = (struct cr4_64 *)(dec_instr.dst_operand.operand);
+ struct cr4_64 * guest_cr4 = (struct cr4_64 *)&(info->ctrl_regs.cr4);
+ *dst_reg = *guest_cr4;
+ }
+ else {
+ struct cr4_32 * dst_reg = (struct cr4_32 *)(dec_instr.dst_operand.operand);
+ struct cr4_32 * guest_cr4 = (struct cr4_32 *)&(info->shdw_pg_state.guest_cr4);
+ *dst_reg = *guest_cr4;
+ }
+
+ } else if (info->shdw_pg_mode == NESTED_PAGING) {
+
+
+ if ((v3_get_vm_cpu_mode(info) == LONG) ||
+ (v3_get_vm_cpu_mode(info) == LONG_32_COMPAT)) {
+ struct cr4_64 * dst_reg = (struct cr4_64 *)(dec_instr.dst_operand.operand);
+ struct cr4_64 * guest_cr4 = (struct cr4_64 *)&(info->ctrl_regs.cr4);
+ *dst_reg = *guest_cr4;
+ } else {
+ struct cr4_32 * dst_reg = (struct cr4_32 *)(dec_instr.dst_operand.operand);
+ struct cr4_32 * guest_cr4 = (struct cr4_32 *)&(info->ctrl_regs.cr4);
+ *dst_reg = *guest_cr4;
+ }
+ }
+
+ info->rip += dec_instr.instr_length;
return 0;
}
+
int v3_handle_cr4_write(struct guest_info * info) {
uchar_t instr[15];
int ret;
if (v3_get_vm_mem_mode(info) == VIRTUAL_MEM) {
struct cr4_32 * new_cr4 = (struct cr4_32 *)(dec_instr.src_operand.operand);
- struct cr4_32 * cr4 = (struct cr4_32 *)&(info->ctrl_regs.cr4);
+ struct cr4_32 * cr4 = (struct cr4_32 *)&(info->shdw_pg_state.guest_cr4);
// if pse, pge, or pae have changed while PG (in any mode) is on
// the side effect is a TLB flush, which means we need to
if ((cpu_mode == PROTECTED) || (cpu_mode == PROTECTED_PAE)) {
struct cr4_32 * new_cr4 = (struct cr4_32 *)(dec_instr.src_operand.operand);
- struct cr4_32 * cr4 = (struct cr4_32 *)&(info->ctrl_regs.cr4);
-
+ struct cr4_32 * shadow_cr4 = (struct cr4_32 *)&(info->ctrl_regs.cr4);
+ struct cr4_32 * guest_cr4 = (struct cr4_32 *)&(info->shdw_pg_state.guest_cr4);
PrintDebug(info->vm_info, info, "OperandVal = %x, length = %d\n", *(uint_t *)new_cr4, dec_instr.src_operand.size);
- PrintDebug(info->vm_info, info, "Old CR4=%x\n", *(uint_t *)cr4);
+ PrintDebug(info->vm_info, info, "Old guest CR4=%x\n", *(uint_t *)guest_cr4);
if ((info->shdw_pg_mode == SHADOW_PAGING)) {
if (v3_get_vm_mem_mode(info) == PHYSICAL_MEM) {
- if ((cr4->pae == 0) && (new_cr4->pae == 1)) {
+ if ((guest_cr4->pae == 0) && (new_cr4->pae == 1)) {
PrintDebug(info->vm_info, info, "Creating PAE passthrough tables\n");
// create 32 bit PAE direct map page table
// reset cr3 to new page tables
info->ctrl_regs.cr3 = *(addr_t*)&(info->direct_map_pt);
- } else if ((cr4->pae == 1) && (new_cr4->pae == 0)) {
+ } else if ((guest_cr4->pae == 1) && (new_cr4->pae == 0)) {
// Create passthrough standard 32bit pagetables
PrintError(info->vm_info, info, "Switching From PAE to Protected mode not supported\n");
return -1;
}
}
- *cr4 = *new_cr4;
- PrintDebug(info->vm_info, info, "New CR4=%x\n", *(uint_t *)cr4);
+ *guest_cr4 = *new_cr4;
+ *shadow_cr4 = *guest_cr4;
+ shadow_cr4->pae = 1; // always on for the shadow pager
+ PrintDebug(info->vm_info, info, "New guest CR4=%x and shadow CR4=%x\n", *(uint_t *)guest_cr4,*(uint_t*)shadow_cr4);
} else if ((cpu_mode == LONG) || (cpu_mode == LONG_32_COMPAT)) {
struct cr4_64 * new_cr4 = (struct cr4_64 *)(dec_instr.src_operand.operand);