more decoder fixes to handle incorrect long mode register decoding

diff --git a/palacios/include/palacios/vmm_decoder.h b/palacios/include/palacios/vmm_decoder.h
index 767fe25..03c5edb 100644 (file)
--- a/palacios/include/palacios/vmm_decoder.h
+++ b/palacios/include/palacios/vmm_decoder.h
@@ -216,11 +216,18 @@ static inline addr_t get_addr_linear(struct guest_info * info, addr_t addr, stru
            return addr + seg->base;
            break;
 
-       case LONG:
+       case LONG: {
+           uint64_t seg_base = 0;
+
            // In long mode the segment bases are disregarded (forced to 0), unless using 
            // FS or GS, then the base addresses are added
-           return addr + seg->base;
 
+           if (seg) {
+               seg_base = seg->base;
+           }
+
+           return addr + seg_base;
+       }
        case LONG_16_COMPAT:
        default:
            PrintError("Unsupported CPU Mode: %d\n", info->cpu_mode);

diff --git a/palacios/include/palacios/vmm_instr_decoder.h b/palacios/include/palacios/vmm_instr_decoder.h
index 3fe838b..6e33c46 100644 (file)
--- a/palacios/include/palacios/vmm_instr_decoder.h
+++ b/palacios/include/palacios/vmm_instr_decoder.h
@@ -1017,23 +1017,24 @@ int decode_rm_operand64(struct guest_info * core, uint8_t * modrm_instr,
        }
     
 
-       /* 
-          Segments should be ignored 
-          // get appropriate segment
-          if (instr->prefixes.cs_override) {
-          seg = &(core->segments.cs);
-          } else if (instr->prefixes.es_override) {
-          seg = &(core->segments.es);
-          } else if (instr->prefixes.ss_override) {
-          seg = &(core->segments.ss);
-          } else if (instr->prefixes.fs_override) {
-          seg = &(core->segments.fs);
-          } else if (instr->prefixes.gs_override) {
-          seg = &(core->segments.gs);
-          } else {
-          seg = &(core->segments.ds);
-          }
-       */
+       
+       //Segments should be ignored 
+       // get appropriate segment
+
+       if (instr->prefixes.cs_override) {
+           seg = &(core->segments.cs);
+       } else if (instr->prefixes.es_override) {
+           seg = &(core->segments.es);
+       } else if (instr->prefixes.ss_override) {
+           seg = &(core->segments.ss);
+       } else if (instr->prefixes.fs_override) {
+           seg = &(core->segments.fs);
+       } else if (instr->prefixes.gs_override) {
+           seg = &(core->segments.gs);
+       } else {
+           seg = &(core->segments.ds);
+       }
+       
 
        operand->operand = ADDR_MASK(get_addr_linear(core, base_addr, seg), 
                                     get_addr_width(core, instr));
@@ -1061,7 +1062,7 @@ static int decode_rm_operand(struct guest_info * core,
        case REAL:
            return decode_rm_operand16(core, instr_ptr, instr, operand, reg_code);
        case LONG:
-           if (instr->prefixes.rex_op_size) {
+           if (instr->prefixes.rex) {
                return decode_rm_operand64(core, instr_ptr, instr, operand, reg_code);
            }
        case PROTECTED: