Palacios Public Git Repository

To checkout Palacios execute

  git clone http://v3vee.org/palacios/palacios.web/palacios.git
This will give you the master branch. You probably want the devel branch or one of the release branches. To switch to the devel branch, simply execute
  cd palacios
  git checkout --track -b devel origin/devel
The other branches are similar.


more decoder work
Jack Lange [Tue, 8 Mar 2011 22:31:39 +0000 (16:31 -0600)]
palacios/include/palacios/vmm_decoder.h
palacios/include/palacios/vmm_instr_decoder.h
palacios/src/palacios/vm_guest.c
palacios/src/palacios/vmm_decoder.c
palacios/src/palacios/vmm_v3dec.c

index a6bee03..7f05064 100644 (file)
@@ -120,6 +120,8 @@ uint8_t v3_get_prefixes(uint8_t * instr, struct x86_prefixes * prefixes);
 
 
 
+void v3_print_instr(struct x86_instr * instr);
+
 
 #define PREFIX_LOCK         0xF0
 #define PREFIX_REPNE        0xF2
index 207da43..15d6271 100644 (file)
@@ -345,10 +345,12 @@ struct sib_byte {
 
 struct v3_gprs;
 
-static inline int decode_gpr(struct v3_gprs * gprs,                    
+static inline int decode_gpr(struct guest_info * core,
                             uint8_t reg_code,
                             struct x86_operand * reg) {
 
+    struct v3_gprs * gprs = &(core->vm_regs);
+
     switch (reg_code) {
        case 0:
            reg->operand = (addr_t)&(gprs->rax);
@@ -391,14 +393,47 @@ static inline int decode_gpr(struct v3_gprs * gprs,
            }
            break;
        default:
+           PrintError("Invalid Reg Code (%d)\n", reg_code);
            reg->operand = 0;
-           break;
+           return -1;
     }
 
     return 0;
 }
 
 
+
+
+static inline int decode_cr(struct guest_info * core,                  
+                            uint8_t reg_code,
+                            struct x86_operand * reg) {
+
+    struct v3_ctrl_regs * crs = &(core->ctrl_regs);
+
+    PrintDebug("\t Ctrl regs %d\n", reg_code);
+
+    switch (reg_code) {
+       case 0:
+           reg->operand = (addr_t)&(crs->cr0);
+           break;
+       case 2:
+           reg->operand = (addr_t)&(crs->cr2);
+           break;
+       case 3:
+           reg->operand = (addr_t)&(crs->cr3);
+           break;
+       case 4:
+           reg->operand = (addr_t)&(crs->cr4);
+           break;
+       default:
+           reg->operand = 0;
+           PrintError("Invalid Reg Code (%d)\n", reg_code);
+           return -1;
+    }
+
+    return 0;
+}
+
 // This converts the displacement into the appropriate masked value
 /* 
    QUESTION: Are the register Values signed ?????
@@ -413,7 +448,7 @@ static inline int decode_gpr(struct v3_gprs * gprs,
                val = (sint32_t)(reg & 0xffffffff);                     \
            } else {                                                    \
                PrintError("Error invalid displacement size (%d)\n", mode); \
-               V3_ASSERT(0);                                           \
+               /*V3_ASSERT(0);*/                                       \
            }                                                           \
            val;                                                        \
        })
@@ -440,7 +475,7 @@ static  int decode_rm_operand16(struct guest_info * core,
        //PrintDebug("first operand = Register (RM=%d)\n",modrm->rm);
        operand->type = REG_OPERAND;
 
-       decode_gpr(gprs, modrm->rm, operand);
+       decode_gpr(core, modrm->rm, operand);
 
     } else {
        struct v3_segment * seg = NULL;
@@ -544,7 +579,7 @@ static int decode_rm_operand32(struct guest_info * core,
        operand->type = REG_OPERAND;
        //    PrintDebug("first operand = Register (RM=%d)\n",modrm->rm);
 
-       decode_gpr(gprs, modrm->rm, operand);
+       decode_gpr(core, modrm->rm, operand);
 
     } else {
        struct v3_segment * seg = NULL;
@@ -1027,3 +1062,114 @@ static op_form_t op_code_to_form(uint8_t * instr, int * length) {
            return INVALID_INSTR;
     }
 }
+
+
+
+static char * op_form_to_str(op_form_t form) {
+
+    switch (form) {
+       case LMSW: return "LMSW";
+       case SMSW: return "SMSW";
+       case CLTS: return "CLTS";
+       case INVLPG: return "INVLPG";
+       case MOV_CR2: return "MOV_CR2";
+       case MOV_2CR: return "MOV_2CR";
+       case MOV_DR2: return "MOV_DR2";
+       case MOV_2DR: return "MOV_2DR";
+       case MOV_SR2: return "MOV_SR2";
+       case MOV_2SR: return "MOV_2SR";
+       case MOV_MEM2_8: return "MOV_MEM2_8";
+       case MOV_MEM2: return "MOV_MEM2";
+       case MOV_2MEM_8: return "MOV_2MEM_8";
+       case MOV_2MEM: return "MOV_2MEM";
+       case MOV_MEM2AL_8: return "MOV_MEM2AL_8";
+       case MOV_MEM2AX: return "MOV_MEM2AX";
+       case MOV_AL2MEM_8: return "MOV_AL2MEM_8";
+       case MOV_AX2MEM: return "MOV_AX2MEM";
+       case MOV_IMM2_8: return "MOV_IMM2_8";
+       case MOV_IMM2: return "MOV_IMM2";
+       case MOVS_8: return "MOVS_8";
+       case MOVS: return "MOVS";
+       case MOVSX_8: return "MOVSX_8";
+       case MOVSX: return "MOVSX";
+       case MOVZX_8: return "MOVZX_8";
+       case MOVZX: return "MOVZX";
+       case HLT: return "HLT";
+       case PUSHF: return "PUSHF";
+       case POPF: return "POPF";
+       case ADC_2MEM_8: return "ADC_2MEM_8";
+       case ADC_2MEM: return "ADC_2MEM";
+       case ADC_MEM2_8: return "ADC_MEM2_8";
+       case ADC_MEM2: return "ADC_MEM2";
+       case ADC_IMM2_8: return "ADC_IMM2_8";
+       case ADC_IMM2: return "ADC_IMM2";
+       case ADC_IMM2SX_8: return "ADC_IMM2SX_8";
+       case ADD_IMM2_8: return "ADD_IMM2_8";
+       case ADD_IMM2: return "ADD_IMM2";
+       case ADD_IMM2SX_8: return "ADD_IMM2SX_8";
+       case ADD_2MEM_8: return "ADD_2MEM_8";
+       case ADD_2MEM: return "ADD_2MEM";
+       case ADD_MEM2_8: return "ADD_MEM2_8";
+       case ADD_MEM2: return "ADD_MEM2";
+       case AND_MEM2_8: return "AND_MEM2_8";
+       case AND_MEM2: return "AND_MEM2";
+       case AND_2MEM_8: return "AND_2MEM_8";
+       case AND_2MEM: return "AND_2MEM";
+       case AND_IMM2_8: return "AND_IMM2_8";
+       case AND_IMM2: return "AND_IMM2";
+       case AND_IMM2SX_8: return "AND_IMM2SX_8";
+       case OR_2MEM_8: return "OR_2MEM_8";
+       case OR_2MEM: return "OR_2MEM";
+       case OR_MEM2_8: return "OR_MEM2_8";
+       case OR_MEM2: return "OR_MEM2";
+       case OR_IMM2_8: return "OR_IMM2_8";
+       case OR_IMM2: return "OR_IMM2";
+       case OR_IMM2SX_8: return "OR_IMM2SX_8";
+       case SUB_2MEM_8: return "SUB_2MEM_8";
+       case SUB_2MEM: return "SUB_2MEM";
+       case SUB_MEM2_8: return "SUB_MEM2_8";
+       case SUB_MEM2: return "SUB_MEM2";
+       case SUB_IMM2_8: return "SUB_IMM2_8";
+       case SUB_IMM2: return "SUB_IMM2";
+       case SUB_IMM2SX_8: return "SUB_IMM2SX_8";
+       case XOR_2MEM_8: return "XOR_2MEM_8";
+       case XOR_2MEM: return "XOR_2MEM";
+       case XOR_MEM2_8: return "XOR_MEM2_8";
+       case XOR_MEM2: return "XOR_MEM2";
+       case XOR_IMM2_8: return "XOR_IMM2_8";
+       case XOR_IMM2: return "XOR_IMM2";
+       case XOR_IMM2SX_8: return "XOR_IMM2SX_8";
+       case INC_8: return "INC_8";
+       case INC: return "INC";
+       case DEC_8: return "DEC_8";
+       case DEC: return "DEC";
+       case NEG_8: return "NEG_8";
+       case NEG: return "NEG"; 
+       case NOT_8: return "NOT_8";
+       case NOT: return "NOT";
+       case XCHG_8: return "XCHG_8";
+       case XCHG: return "XCHG";
+       case SETB: return "SETB";
+       case SETBE: return "SETBE";
+       case SETL: return "SETL";
+       case SETLE: return "SETLE";
+       case SETNB: return "SETNB";
+       case SETNBE: return "SETNBE";
+       case SETNL: return "SETNL";
+       case SETNLE: return "SETNLE";
+       case SETNO: return "SETNO";
+       case SETNP: return "SETNP";
+       case SETNS: return "SETNS";
+       case SETNZ: return "SETNZ";
+       case SETP: return "SETP";
+       case SETS: return "SETS";
+       case SETZ: return "SETZ";
+       case SETO: return "SETO";
+       case STOS_8: return "STOS_8";
+       case STOS: return "STOS";
+
+       case INVALID_INSTR:
+       default:
+           return "INVALID_INSTR";
+    }
+}
index 73926cc..7a10e66 100644 (file)
@@ -252,14 +252,14 @@ void v3_print_ctrl_regs(struct guest_info * info) {
     V3_Print("32 bit Ctrl Regs:\n");
 
     for (i = 0; reg_names[i] != NULL; i++) {
-       V3_Print("\t%s=0x%p\n", reg_names[i], (void *)(addr_t)reg_ptr[i]);  
+       V3_Print("\t%s=0x%p (at %p)\n", reg_names[i], (void *)(addr_t)reg_ptr[i], &(reg_ptr[i]));  
     }
 
     V3_Print("\tEFER=0x%p\n", (void*)(addr_t)(guest_state->efer));
 
 }
 
-
+#if 0
 static int safe_gva_to_hva(struct guest_info * info, addr_t linear_addr, addr_t * host_addr) {
     /* select the proper translation based on guest mode */
     if (info->mem_mode == PHYSICAL_MEM) {
@@ -282,6 +282,8 @@ static int v3_print_disassembly(struct guest_info * info) {
     /* start disassembly 64 bytes before current RIP, continue 32 bytes after */
     rip = (addr_t) info->rip - 64;
     while ((int) (rip - info->rip) < 32) {
+       V3_Print("disassembly step\n");
+
        /* always print RIP, even if the instructions before were bad */
        if (!passed_rip && rip >= info->rip) {
            if (rip != info->rip) {
@@ -303,11 +305,13 @@ static int v3_print_disassembly(struct guest_info * info) {
            rip++;
            continue;
        }
+
     }
 
     return 0;
 }
 
+#endif
 
 void v3_print_guest_state(struct guest_info * info) {
     addr_t linear_addr = 0; 
@@ -334,7 +338,7 @@ void v3_print_guest_state(struct guest_info * info) {
 
     v3_print_stack(info);
 
-    v3_print_disassembly(info);
+    //  v3_print_disassembly(info);
 }
 
 void v3_print_guest_state_all(struct v3_vm_info * vm) {
@@ -410,7 +414,7 @@ void v3_print_GPRs(struct guest_info * info) {
     V3_Print("32 bit GPRs:\n");
 
     for (i = 0; reg_names[i] != NULL; i++) {
-       V3_Print("\t%s=0x%p\n", reg_names[i], (void *)(addr_t)reg_ptr[i]);  
+       V3_Print("\t%s=0x%p (at %p)\n", reg_names[i], (void *)(addr_t)reg_ptr[i], &(reg_ptr[i]));  
     }
 }
 
@@ -428,7 +432,7 @@ void v3_print_GPRs(struct guest_info * info) {
     V3_Print("64 bit GPRs:\n");
 
     for (i = 0; reg_names[i] != NULL; i++) {
-       V3_Print("\t%s=0x%p\n", reg_names[i], (void *)(addr_t)reg_ptr[i]);  
+       V3_Print("\t%s=0x%p (at %p)\n", reg_names[i], (void *)(addr_t)reg_ptr[i], &(reg_ptr[i]));  
     }
 }
 
index 676fd6d..f70e784 100644 (file)
@@ -104,3 +104,128 @@ void v3_strip_rep_prefix(uchar_t * instr, int length) {
        }
     }
 }
+
+
+static char * op_type_to_str(v3_op_type_t type) {
+    switch (type) {
+       case V3_OP_MOVCR2: return "V3_OP_MOVCR2"; 
+       case V3_OP_MOV2CR: return "V3_OP_MOV2CR"; 
+       case V3_OP_SMSW: return "V3_OP_SMSW"; 
+       case V3_OP_LMSW: return "V3_OP_LMSW"; 
+       case V3_OP_CLTS: return "V3_OP_CLTS";
+       case V3_OP_INVLPG: return "V3_OP_INVLPG";
+       case V3_OP_ADC: return "V3_OP_ADC"; 
+       case V3_OP_ADD: return "V3_OP_ADD";
+       case V3_OP_AND: return "V3_OP_AND"; 
+       case V3_OP_OR: return "V3_OP_OR"; 
+       case V3_OP_XOR: return "V3_OP_XOR"; 
+       case V3_OP_SUB: return "V3_OP_SUB";
+       case V3_OP_INC: return "V3_OP_INC"; 
+       case V3_OP_DEC: return "V3_OP_DEC"; 
+       case V3_OP_NEG: return "V3_OP_NEG"; 
+       case V3_OP_MOV: return "V3_OP_MOV"; 
+       case V3_OP_NOT: return "V3_OP_NOT"; 
+       case V3_OP_XCHG: return "V3_OP_XCHG"; 
+       case V3_OP_SETB: return "V3_OP_SETB"; 
+       case V3_OP_SETBE: return "V3_OP_SETBE"; 
+       case V3_OP_SETL: return "V3_OP_SETL"; 
+       case V3_OP_SETLE: return "V3_OP_SETLE"; 
+       case V3_OP_SETNB: return "V3_OP_SETNB"; 
+       case V3_OP_SETNBE: return "V3_OP_SETNBE"; 
+       case V3_OP_SETNL: return "V3_OP_SETNL"; 
+       case V3_OP_SETNLE: return "V3_OP_SETNLE"; 
+       case V3_OP_SETNO: return "V3_OP_SETNO"; 
+       case V3_OP_SETNP: return "V3_OP_SETNP";
+       case V3_OP_SETNS: return "V3_OP_SETNS"; 
+       case V3_OP_SETNZ: return "V3_OP_SETNZ"; 
+       case V3_OP_SETO: return "V3_OP_SETO"; 
+       case V3_OP_SETP: return "V3_OP_SETP"; 
+       case V3_OP_SETS: return "V3_OP_SETS"; 
+       case V3_OP_SETZ: return "V3_OP_SETZ"; 
+       case V3_OP_MOVS: return "V3_OP_MOVS"; 
+       case V3_OP_STOS: return "V3_OP_STOS"; 
+       case V3_OP_MOVZX: return "V3_OP_MOVZX"; 
+       case V3_OP_MOVSX: return "V3_OP_MOVSX";
+       case V3_INVALID_OP: 
+       default:
+           return "V3_INVALID_OP";
+    }
+}
+
+
+static char * operand_type_to_str(v3_operand_type_t op) {
+    switch (op) {
+       case REG_OPERAND: return "REG_OPERAND";
+       case MEM_OPERAND: return "MEM_OPERAND";
+       case IMM_OPERAND: return "IMM_OPERAND";
+       default:
+           return "INVALID_OPERAND";
+    }
+}
+
+
+static const ullong_t mask_1 = 0x00000000000000ffLL;
+static const ullong_t mask_2 = 0x000000000000ffffLL;
+static const ullong_t mask_4 = 0x00000000ffffffffLL;
+static const ullong_t mask_8 = 0xffffffffffffffffLL;
+
+
+#define MASK(val, length) ({                   \
+           ullong_t mask = 0x0LL;              \
+           switch (length) {                   \
+               case 1:                         \
+                   mask = mask_1;              \
+                   break;                      \
+               case 2:                         \
+                   mask = mask_2;              \
+                   break;                      \
+               case 4:                         \
+                   mask = mask_4;              \
+                   break;                      \
+               case 8:                         \
+                   mask = mask_8;              \
+                   break;                      \
+           }                                   \
+           val & mask;                         \
+       })
+
+void v3_print_instr(struct x86_instr * instr) {
+    V3_Print("Instr: %s (Len: %d)\n", op_type_to_str(instr->op_type), instr->instr_length);
+
+    V3_Print("Prefixes= %x\n", *(uint32_t *)&(instr->prefixes));
+
+    if (instr->is_str_op) {
+       V3_Print("String OP (len=%d)\n", (uint32_t)instr->str_op_length);
+    }
+
+    V3_Print("Number of operands: %d\n", instr->num_operands);
+
+    if (instr->num_operands > 0) {
+       V3_Print("Src Operand (%s)\n", operand_type_to_str(instr->src_operand.type));
+       V3_Print("\tLen=%d (Addr: %p)\n", instr->src_operand.size, 
+                (void *)instr->src_operand.operand);
+       if (instr->src_operand.type == REG_OPERAND) {
+           V3_Print("\tVal: %p\n", (void *)MASK(*(uint64_t *)(instr->src_operand.operand), instr->src_operand.size));
+       }
+    }
+
+    if (instr->num_operands > 1) {
+       V3_Print("Dst Operand (%s)\n", operand_type_to_str(instr->dst_operand.type));
+       V3_Print("\tLen=%d (Addr: %p)\n", instr->dst_operand.size, 
+                (void *)instr->dst_operand.operand);
+       if (instr->dst_operand.type == REG_OPERAND) {
+           V3_Print("\tVal: %p\n", (void *)MASK(*(uint64_t *)(instr->dst_operand.operand), instr->dst_operand.size));
+       }
+    }
+
+    if (instr->num_operands > 2) {
+       V3_Print("Third Operand (%s)\n", operand_type_to_str(instr->third_operand.type));
+       V3_Print("\tLen=%d (Addr: %p)\n", instr->third_operand.size, 
+                (void *)instr->third_operand.operand);
+       if (instr->third_operand.type == REG_OPERAND) {
+           V3_Print("\tVal: %p\n", (void *)MASK(*(uint64_t *)(instr->third_operand.operand), instr->third_operand.size));
+       }
+    }
+}
+
+
index d3a59d1..f02d04b 100644 (file)
@@ -54,7 +54,7 @@ static int parse_operands(struct guest_info * core, uint8_t * instr_ptr, struct
 
 
 int v3_disasm(struct guest_info * info, void *instr_ptr, addr_t * rip, int mark) {
-    return 0;
+    return -1;
 }
 
 
@@ -69,7 +69,7 @@ int v3_deinit_decoder(struct guest_info * core) {
 
 
 int v3_encode(struct guest_info * info, struct x86_instr * instr, uint8_t * instr_buf) {
-    return 0;
+    return -1;
 }
 
 
@@ -78,6 +78,9 @@ int v3_decode(struct guest_info * core, addr_t instr_ptr, struct x86_instr * ins
     int ret = 0;
     int length = 0;
 
+
+    V3_Print("Decoding Instruction at %p\n", (void *)instr_ptr);
+
     memset(instr, 0, sizeof(struct x86_instr));
 
     // scan for prefixes
@@ -89,6 +92,9 @@ int v3_decode(struct guest_info * core, addr_t instr_ptr, struct x86_instr * ins
 
     form = op_code_to_form((uint8_t *)(instr_ptr + length), &length);
 
+
+    V3_Print("\t decoded as (%s)\n", op_form_to_str(form));
+
     if (form == INVALID_INSTR) {
        PrintError("Could not find instruction form (%x)\n", *(uint32_t *)(instr_ptr + length));
        return -1;
@@ -108,6 +114,8 @@ int v3_decode(struct guest_info * core, addr_t instr_ptr, struct x86_instr * ins
     instr->instr_length += length;
 
 
+    v3_print_instr(instr);
+
     return 0;
 }
 
@@ -116,11 +124,13 @@ static int parse_operands(struct guest_info * core, uint8_t * instr_ptr,
                          struct x86_instr * instr, op_form_t form) {
     // get operational mode of the guest for operand width
     uint8_t operand_width = get_operand_width(core, instr, form);
-    uint8_t addr_width = get_addr_width(core, instr, form);;
+    uint8_t addr_width = get_addr_width(core, instr, form);
     int ret = 0;
     uint8_t * instr_start = instr_ptr;
     
 
+    PrintDebug("\tOperand width=%d, Addr width=%d\n", operand_width, addr_width);
+
     switch (form) {
        case ADC_IMM2_8:
        case ADD_IMM2_8:
@@ -199,7 +209,7 @@ static int parse_operands(struct guest_info * core, uint8_t * instr_ptr,
            instr->src_operand.type = REG_OPERAND;
            instr->src_operand.size = operand_width;
 
-           decode_gpr(&(core->vm_regs), reg_code, &(instr->src_operand));
+           decode_gpr(core, reg_code, &(instr->src_operand));
 
            instr->num_operands = 2;
            break;
@@ -232,7 +242,7 @@ static int parse_operands(struct guest_info * core, uint8_t * instr_ptr,
 
            instr->dst_operand.size = operand_width;
            instr->dst_operand.type = REG_OPERAND;
-           decode_gpr(&(core->vm_regs), reg_code, &(instr->dst_operand));
+           decode_gpr(core, reg_code, &(instr->dst_operand));
 
            instr->num_operands = 2;
 
@@ -277,22 +287,113 @@ static int parse_operands(struct guest_info * core, uint8_t * instr_ptr,
            }
 
            // Source: DS:(E)SI
-           // Source: ES:(E)DI
+           // Destination: ES:(E)DI
 
            instr->src_operand.type = MEM_OPERAND;
            instr->src_operand.size = operand_width;
            instr->src_operand.operand = get_addr_linear(core,  MASK(core->vm_regs.rsi, addr_width), &(core->segments.ds));
 
-           instr->src_operand.type = MEM_OPERAND;
-           instr->src_operand.size = operand_width;
-           instr->src_operand.operand = get_addr_linear(core, MASK(core->vm_regs.rdi, addr_width), &(core->segments.es));
+           instr->dst_operand.type = MEM_OPERAND;
+           instr->dst_operand.size = operand_width;
+           instr->dst_operand.operand = get_addr_linear(core, MASK(core->vm_regs.rdi, addr_width), &(core->segments.es));
 
            instr->num_operands = 2;
 
            break;
+
+           case MOV_2CR: {
+               uint8_t reg_code = 0;
+
+               instr->src_operand.size = operand_width;
+
+               ret = decode_rm_operand(core, instr_ptr, instr, &(instr->src_operand),
+                                       &reg_code);
+
+               if (ret == -1) {
+                   PrintError("Error decoding operand for (%s)\n", op_form_to_str(form));
+                   return -1;
+               }
+               
+               instr_ptr += ret;
+
+               instr->dst_operand.type = REG_OPERAND;
+               instr->dst_operand.size = operand_width;
+               decode_cr(core, reg_code, &(instr->dst_operand));
+
+               instr->num_operands = 2;
+               break;
+           }
+           case MOV_CR2: {
+               uint8_t reg_code = 0;
+
+               instr->dst_operand.size = operand_width;
+
+               ret = decode_rm_operand(core, instr_ptr, instr, &(instr->dst_operand),
+                                       &reg_code);
+
+               if (ret == -1) {
+                   PrintError("Error decoding operand for (%s)\n", op_form_to_str(form));
+                   return -1;
+               }
+
+               instr_ptr += ret;
+               
+               instr->src_operand.type = REG_OPERAND;
+               instr->src_operand.size = operand_width;
+               decode_cr(core, reg_code, &(instr->src_operand));
+
+               instr->num_operands = 2;
+               break;
+           }
+           case STOS:
+           case STOS_8: {
+               instr->is_str_op = 1;
+               
+               if (instr->prefixes.rep == 1) {
+                   instr->str_op_length = MASK(core->vm_regs.rcx, operand_width);
+               } else {
+                   instr->str_op_length = 1;
+               }
+               
+               instr->src_operand.size = operand_width;
+               instr->src_operand.type = REG_OPERAND;
+               instr->src_operand.operand = (addr_t)&(core->vm_regs.rax);
+
+               instr->dst_operand.type = MEM_OPERAND;
+               instr->dst_operand.size = operand_width;
+               instr->dst_operand.operand = get_addr_linear(core, MASK(core->vm_regs.rdi, addr_width), &(core->segments.es));
+
+               instr->num_operands = 2;
+
+               break;
+           }
+           case INVLPG: {
+               uint8_t reg_code = 0;
+
+               // We use the dst operand here to maintain bug-for-bug compatibility with XED
+
+               instr->dst_operand.size = operand_width;
+
+               ret = decode_rm_operand(core, instr_ptr, instr, &(instr->dst_operand), &reg_code);
+
+               if (ret == -1) {
+                   PrintError("Error decoding operand for (%s)\n", op_form_to_str(form));
+                   return -1;
+               }
+
+               instr_ptr += ret;
+
+               instr->num_operands = 1;
+               break;
+           }
+           case CLTS: {
+               // no operands. 
+               break;
+
+           }
        }
        default:
-           PrintError("Invalid Instruction form: %d\n", form);
+           PrintError("Invalid Instruction form: %s\n", op_form_to_str(form));
            return -1;
     }