#include <geekos/vmm.h>
#include <geekos/vmcb.h>
#include <geekos/vmm_emulate.h>
+#include <geekos/vm_guest_mem.h>
+#include <geekos/vmm_ctrl_regs.h>
-int handle_cr0_write(guest_info_t * info, ullong_t * new_cr0) {
- // vmcb_ctrl_t * ctrl_area = GET_VMCB_CTRL_AREA((vmcb_t *)(info->vmm_data));
- //vmcb_saved_state_t * guest_state = GET_VMCB_SAVE_STATE_AREA((vmcb_t*)(info->vmm_data));
+int handle_cr0_write(struct guest_info * info) {
+ //vmcb_ctrl_t * ctrl_area = GET_VMCB_CTRL_AREA((vmcb_t *)(info->vmm_data));
+ vmcb_saved_state_t * guest_state = GET_VMCB_SAVE_STATE_AREA((vmcb_t*)(info->vmm_data));
+ char instr[15];
-
- /*
+
if (info->cpu_mode == REAL) {
- addr_t host_addr;
- shadow_region_t * region = get_shadow_region_by_addr(&(info->mem_map), (addr_t)(info->rip));
- if (!region || (region->host_type != HOST_REGION_PHYSICAL_MEMORY)) {
- //PANIC
+ int index = 0;
+ int ret;
+
+ // The real rip address is actually a combination of the rip + CS base
+ ret = read_guest_pa_memory(info, (addr_t)guest_state->rip, 15, instr);
+ if (ret != 0) {
+ // I think we should inject a GPF into the guest
+ PrintDebug("Could not read instruction (ret=%d)\n", ret);
return -1;
}
- guest_paddr_to_host_paddr(region, (addr_t)(info->rip), &host_addr);
- // pa to va
+ while (is_prefix_byte(instr[index])) {
+ PrintDebug("instr(%d): 0x%x\n", index, instr[index]);
+ index++;
+ }
+ PrintDebug("instr(%d): 0x%x\n", index, instr[index]);
+ PrintDebug("instr(%d): 0x%x\n", index+1, instr[index + 1]);
+
+ if ((instr[index] == cr_access_byte) &&
+ (instr[index + 1] == lmsw_byte) &&
+ (MODRM_REG(instr[index + 2]) == lmsw_reg_byte)) {
+
+ addr_t first_operand;
+ addr_t second_operand;
+ struct cr0_real *old_cr0;
+ struct cr0_real *new_cr0;
+
+ // LMSW
+ // decode mod/RM
+ index += 2;
+
+ old_cr0 = (struct cr0_real*)&(guest_state->cr0);
+
+ if (decode_operands16(&(info->vm_regs), instr + index, &first_operand, &second_operand, REG16) != 0) {
+ // error... don't know what to do
+ return -1;
+ }
+
+ index += 3;
+ new_cr0 = (struct cr0_real *)first_operand;
- PrintDebug("Instr: %.4x\n", *(ushort_t*)host_addr);
-
- if ((*(ushort_t*)host_addr) == LMSW_EAX) {
- PrintDebug("lmsw from eax (0x%x)\n", guest_state->rax);
+ if ((new_cr0->pe == 1) && (old_cr0->pe == 0)) {
+ info->cpu_mode = PROTECTED;
+ }
+
+
+ if (info->page_mode == SHADOW_PAGING) {
+ struct cr0_real * virt_cr0 = (struct cr0_real*)&(info->shdw_pg_state.guest_cr0);
+
+ /* struct cr0_real is only 4 bits wide,
+ * so we can overwrite the old_cr0 without worrying about the shadow fields
+ */
+ *old_cr0 = *new_cr0;
+ *virt_cr0 = *new_cr0;
+ } else {
+ // for now we just pass through....
+ *old_cr0 = *new_cr0;
+ }
+
+ PrintDebug("index = %d, rip = %x\n", index, (ulong_t)(info->rip));
+ info->rip += index;
+ PrintDebug("new_rip = %x\n", (ulong_t)(info->rip));
+ } else if ((instr[index] == cr_access_byte) &&
+ (instr[index + 1] == clts_byte)) {
+ // CLTS
+ } else {
+ // unsupported instruction, UD the guest
+ return -1;
}
- }*/
+
+
+ } else if (info->cpu_mode == PROTECTED) {
+ PrintDebug("Protected Mode write to CR0\n");
+ while(1);
+ } else {
+ PrintDebug("Unknown Mode write to CR0\n");
+ while(1);
+ }
return 0;
}