Changeset 102549 in vbox

Timestamp:

Dec 8, 2023 3:57:39 PM (10 months ago)

Author:

vboxsync

Message:

VMM/IEM: Must truncate constant variable values according to the type size, since we're not getting any help from the C compiler here. bugref:10371

Location:

trunk/src/VBox/VMM

Files:

• Makefile.kmk (modified) (1 diff)
• VMMAll/IEMAllAImpl-arm64.S (added)
• VMMAll/IEMAllN8veRecompiler.cpp (modified) (5 diffs)
• testcase/Makefile.kmk (modified) (1 diff)

trunk/src/VBox/VMM/Makefile.kmk

@@ -233 +233 @@
         $(if-expr !defined(IEM_WITHOUT_ASSEMBLY),VMMAll/IEMAllAImpl.asm,) \
         VMMAll/VMMAllA.asm
+VBoxVMM_SOURCES.arm64 += \
+        VMMAll/IEMAllAImpl-arm64.S
 ifdef VBOX_WITH_VUSB
  VBoxVMM_SOURCES += VMMR3/PDMUsb.cpp

trunk/src/VBox/VMM/VMMAll/IEMAllN8veRecompiler.cpp

@@ -3381 +3381 @@
 {
     Assert(enmGstReg < kIemNativeGstReg_End && g_aGstShadowInfo[enmGstReg].cb != 0);
-#ifdef LOG_ENABLED
+#if defined(LOG_ENABLED) || defined(VBOX_STRICT)
     static const char * const s_pszIntendedUse[] = { "fetch", "update", "full write", "destructive calc" };
 #endif
@@ -6104 +6104 @@
 
     pReNative->Core.aVars[idxVar].u.uValue = uValue;
+    AssertMsg(   pReNative->Core.aVars[idxVar].cbVar >= sizeof(uint64_t)
+              || pReNative->Core.aVars[idxVar].u.uValue < RT_BIT_64(pReNative->Core.aVars[idxVar].cbVar * 8),
+              ("idxVar=%d cbVar=%u uValue=%#RX64\n", idxVar, pReNative->Core.aVars[idxVar].cbVar, uValue));
 }
 
@@ -6183 +6186 @@
 {
     uint8_t const idxVar = iemNativeArgAllocInt(pReNative, iArgNo, cbType);
+
+    /* Since we're using a generic uint64_t value type, we must truncate it if
+       the variable is smaller otherwise we may end up with too large value when
+       scaling up a imm8 w/ sign-extension.
+
+       This caused trouble with a "add bx, 0xffff" instruction (around f000:ac60
+       in the bios, bx=1) when running on arm, because clang expect 16-bit
+       register parameters to have bits 16 and up set to zero.  Instead of
+       setting x1 = 0xffff we ended up with x1 = 0xffffffffffffff and the wrong
+       CF value in the result.  */
+    switch (cbType)
+    {
+        case sizeof(uint8_t):   uValue &= UINT64_C(0xff); break;
+        case sizeof(uint16_t):  uValue &= UINT64_C(0xffff); break;
+        case sizeof(uint32_t):  uValue &= UINT64_C(0xffffffff); break;
+    }
     iemNativeVarSetKindToConst(pReNative, idxVar, uValue);
     return idxVar;
@@ -6213 +6232 @@
 {
     uint8_t const idxVar = iemNativeVarAllocInt(pReNative, cbType);
+
+    /* Since we're using a generic uint64_t value type, we must truncate it if
+       the variable is smaller otherwise we may end up with too large value when
+       scaling up a imm8 w/ sign-extension. */
+    switch (cbType)
+    {
+        case sizeof(uint8_t):   uValue &= UINT64_C(0xff); break;
+        case sizeof(uint16_t):  uValue &= UINT64_C(0xffff); break;
+        case sizeof(uint32_t):  uValue &= UINT64_C(0xffffffff); break;
+    }
     iemNativeVarSetKindToConst(pReNative, idxVar, uValue);
     return idxVar;
@@ -11112 +11141 @@
     }
 #endif
+    /*iemNativeDisassembleTb(pTb, DBGFR3InfoLogRelHlp());*/
 
     STAM_REL_PROFILE_STOP(&pVCpu->iem.s.StatNativeRecompilation, a);

trunk/src/VBox/VMM/testcase/Makefile.kmk

@@ -349 +349 @@
         $(TSTIEMAIMPL_TEST_DATA_DEPS)
 
-tstIEMAImpl_SOURCES.arm64 += tstIEMAImplDataSseBinary.S
+tstIEMAImpl_SOURCES.arm64  = \
+        tstIEMAImplDataSseBinary.S \
+        ../VMMAll/IEMAllAImpl-arm64.S
 tstIEMAImplDataSseBinary.S_DEPS   = \
         $(TSTIEMAIMPL_TEST_DATA_DEPS)