Changeset 95307 in vbox for trunk/src

Timestamp:

Jun 19, 2022 8:37:16 PM (3 years ago)

Author:

vboxsync

Message:

VMM/IEMAll.cpp: Some data TLB tweaking. bugref:9898

File:

• trunk/src/VBox/VMM/VMMAll/IEMAll.cpp (modified) (5 diffs)

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

@@ -6090 +6090 @@
 {
     /*
-     * Check the input and figure out which mapping entry to use.
+     * Check the input, check segment access and adjust address
+     * with segment base.
      */
     Assert(cbMem <= 64 || cbMem == 512 || cbMem == 108 || cbMem == 104 || cbMem == 94); /* 512 is the max! */
@@ -6096 +6097 @@
     Assert(pVCpu->iem.s.cActiveMappings < RT_ELEMENTS(pVCpu->iem.s.aMemMappings));
 
+    VBOXSTRICTRC rcStrict = iemMemApplySegment(pVCpu, fAccess, iSegReg, cbMem, &GCPtrMem);
+    if (rcStrict == VINF_SUCCESS) { /*likely*/ }
+    else longjmp(*pVCpu->iem.s.CTX_SUFF(pJmpBuf), VBOXSTRICTRC_VAL(rcStrict));
+
+    /*
+     * Figure out which mapping entry to use.
+     */
     unsigned iMemMap = pVCpu->iem.s.iNextMapping;
     if (   iMemMap >= RT_ELEMENTS(pVCpu->iem.s.aMemMappings)
@@ -6109 +6117 @@
 
     /*
-     * Map the memory, checking that we can actually access it.  If something
-     * slightly complicated happens, fall back on bounce buffering.
+     * Crossing a page boundary?
      */
-    VBOXSTRICTRC rcStrict = iemMemApplySegment(pVCpu, fAccess, iSegReg, cbMem, &GCPtrMem);
-    if (rcStrict == VINF_SUCCESS) { /*likely*/ }
-    else longjmp(*pVCpu->iem.s.CTX_SUFF(pJmpBuf), VBOXSTRICTRC_VAL(rcStrict));
-
-    /* Crossing a page boundary? */
     if ((GCPtrMem & GUEST_PAGE_OFFSET_MASK) + cbMem <= GUEST_PAGE_SIZE)
     { /* No (likely). */ }
@@ -6583 +6585 @@
  * @param   GCPtrMem            The address of the guest memory.
  */
-static uint32_t iemMemFetchDataU32SafeJmp(PVMCPUCC pVCpu, uint8_t iSegReg, RTGCPTR GCPtrMem) RT_NOEXCEPT
+uint32_t iemMemFetchDataU32SafeJmp(PVMCPUCC pVCpu, uint8_t iSegReg, RTGCPTR GCPtrMem) RT_NOEXCEPT
 {
     uint32_t const *pu32Src = (uint32_t const *)iemMemMapJmp(pVCpu, sizeof(*pu32Src), iSegReg, GCPtrMem, IEM_ACCESS_DATA_R);
@@ -6652 +6654 @@
        outdated page pointer, or other troubles. */
     Log10(("iemMemFetchDataU32Jmp: %u:%RGv fallback\n", iSegReg, GCPtrMem));
+    return iemMemFetchDataU32SafeJmp(pVCpu, iSegReg, GCPtrMem);
+
+# else
+    uint32_t const *pu32Src = (uint32_t const *)iemMemMapJmp(pVCpu, sizeof(*pu32Src), iSegReg, GCPtrMem, IEM_ACCESS_DATA_R);
+    uint32_t const  u32Ret  = *pu32Src;
+    iemMemCommitAndUnmapJmp(pVCpu, (void *)pu32Src, IEM_ACCESS_DATA_R);
+    return u32Ret;
 # endif
-    return iemMemFetchDataU32SafeJmp(pVCpu, iSegReg, GCPtrMem);
 }
 #endif