Changeset 104784 in vbox for trunk/src/VBox

Timestamp:

May 26, 2024 5:45:30 PM (6 months ago)

Author:

vboxsync

Message:

VMM/IEM: Add helper to ignore the VEX.W prefix for non 64-bit code as required by some instructions, fixes some bootsector testcases, bugref:9898

Location:

trunk/src/VBox/VMM

Files:

• VMMAll/IEMAllInstVexMap2.cpp.h (modified) (6 diffs)
• VMMAll/IEMAllInstVexMap3.cpp.h (modified) (1 diff)
• include/IEMOpHlp.h (modified) (1 diff)
• testcase/tstIEMCheckMc.cpp (modified) (1 diff)

trunk/src/VBox/VMM/VMMAll/IEMAllInstVexMap2.cpp.h

@@ -2275 +2275 @@
 {
     IEMOP_MNEMONIC3(VEX_RVM, ANDN, andn, Gy, By, Ey, DISOPTYPE_HARMLESS, IEMOPHINT_VEX_L_ZERO);
+    IEMOP_HLP_IGNORE_VEX_W_PREFIX_IF_NOT_IN_64BIT();
     IEMOP_VERIFICATION_UNDEFINED_EFLAGS(X86_EFL_AF | X86_EFL_PF);
     uint8_t bRm; IEM_OPCODE_GET_NEXT_U8(&bRm);
@@ -2377 +2378 @@
 /** Body for the vex group 17 instructions. */
 #define IEMOP_BODY_By_Ey(a_Instr) \
+    IEMOP_HLP_IGNORE_VEX_W_PREFIX_IF_NOT_IN_64BIT(); \
     IEMOP_VERIFICATION_UNDEFINED_EFLAGS(X86_EFL_AF | X86_EFL_PF); \
     if (IEM_IS_MODRM_REG_MODE(bRm)) \
@@ -2545 +2547 @@
 /** Body for BZHI, BEXTR, ++; assumes VEX.L must be 0. */
 #define IEMOP_BODY_Gy_Ey_By(a_Instr, a_fFeatureMember, a_fUndefFlags) \
+    IEMOP_HLP_IGNORE_VEX_W_PREFIX_IF_NOT_IN_64BIT(); \
     IEMOP_VERIFICATION_UNDEFINED_EFLAGS(a_fUndefFlags); \
     uint8_t bRm; IEM_OPCODE_GET_NEXT_U8(&bRm); \
@@ -2641 +2644 @@
 /** Body for SARX, SHLX, SHRX; assumes VEX.L must be 0. */
 #define IEMOP_BODY_Gy_Ey_By_NoEflags(a_Instr, a_fFeatureMember) \
+    IEMOP_HLP_IGNORE_VEX_W_PREFIX_IF_NOT_IN_64BIT(); \
     uint8_t bRm; IEM_OPCODE_GET_NEXT_U8(&bRm); \
     if (IEM_IS_MODRM_REG_MODE(bRm)) \
@@ -2740 +2744 @@
 /** Body for PDEP and PEXT (similar to ANDN, except no EFLAGS). */
 #define IEMOP_BODY_Gy_By_Ey_NoEflags(a_Instr, a_fFeatureMember) \
+    IEMOP_HLP_IGNORE_VEX_W_PREFIX_IF_NOT_IN_64BIT(); \
     uint8_t bRm; IEM_OPCODE_GET_NEXT_U8(&bRm); \
     if (IEM_IS_MODRM_REG_MODE(bRm)) \
@@ -2855 +2860 @@
 {
     IEMOP_MNEMONIC4(VEX_RVM, MULX, mulx, Gy, By, Ey, rDX, DISOPTYPE_HARMLESS, IEMOPHINT_VEX_L_ZERO);
+    IEMOP_HLP_IGNORE_VEX_W_PREFIX_IF_NOT_IN_64BIT();
     uint8_t bRm; IEM_OPCODE_GET_NEXT_U8(&bRm);
     if (IEM_IS_MODRM_REG_MODE(bRm))

trunk/src/VBox/VMM/VMMAll/IEMAllInstVexMap3.cpp.h

@@ -1786 +1786 @@
 {
     IEMOP_MNEMONIC3(VEX_RMI, RORX, rorx, Gy, Ey, Ib, DISOPTYPE_HARMLESS, IEMOPHINT_VEX_L_ZERO | IEMOPHINT_VEX_V_ZERO);
+    IEMOP_HLP_IGNORE_VEX_W_PREFIX_IF_NOT_IN_64BIT();
     uint8_t bRm; IEM_OPCODE_GET_NEXT_U8(&bRm);
     if (IEM_IS_MODRM_REG_MODE(bRm))

trunk/src/VBox/VMM/include/IEMOpHlp.h

@@ -411 +411 @@
     } while (0)
 
+/** The instruction ignores any REX.W/VEX.W prefix if not in 64-bit mode. */
+#define IEMOP_HLP_IGNORE_VEX_W_PREFIX_IF_NOT_IN_64BIT() \
+    do \
+    { \
+        if (!IEM_IS_64BIT_CODE(pVCpu)) \
+            pVCpu->iem.s.fPrefixes &= ~IEM_OP_PRF_SIZE_REX_W; \
+    } while (0)
+
 /**
  * Done decoding.

trunk/src/VBox/VMM/testcase/tstIEMCheckMc.cpp

@@ -164 +164 @@
 #define IEMOP_HLP_DEFAULT_64BIT_OP_SIZE_AND_INTEL_IGNORES_OP_SIZE_PREFIX()                          do { } while (0)
 #define IEMOP_HLP_CLEAR_REX_NOT_BEFORE_OPCODE(a_szPrf)      do { } while (0)
+#define IEMOP_HLP_IGNORE_VEX_W_PREFIX_IF_NOT_IN_64BIT()     do { } while (0)
 #define IEMOP_HLP_DONE_DECODING_NO_LOCK_PREFIX()            do { } while (0)
 #define IEMOP_HLP_DONE_DECODING_NO_LOCK_PREFIX_EX(a_fFeature)                                       do { } while (0)