Changeset 104877 in vbox

Timestamp:

Jun 10, 2024 3:15:11 PM (10 months ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

163477

Message:

VMM/IEM: Removed double checking of the physical TLB revision in iemOpcodeFetchBytesJmp as it introduces an unnecessary race condition and the fallback for the 2nd check is completely wrong. This was causing the DBGFSTOP in the main IEM loop to hit among other things. Also corrected the incorrect throwing of VINF_IEM_REEXEC_BREAK from iemNativeHlpMemCodeNewPageTlbMiss. bugref:10371

Location:

trunk/src/VBox/VMM/VMMAll

Files:

• IEMAll.cpp (modified) (1 diff)
• IEMAllN8veRecompBltIn.cpp (modified) (2 diffs)
• IEMAllThrdRecompiler.cpp (modified) (1 diff)

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

@@ -1015 +1015 @@
         /*
          * Try do a direct read using the pbMappingR3 pointer.
+         * Note! Do not recheck the physical TLB revision number here as we have the
+         *       wrong response to changes in the else case.  If someone is updating
+         *       pVCpu->iem.s.CodeTlb.uTlbPhysRev in parallel to us, we should be fine
+         *       pretending we always won the race.
          */
-        if (    (pTlbe->fFlagsAndPhysRev & (IEMTLBE_F_PHYS_REV | IEMTLBE_F_NO_MAPPINGR3 | IEMTLBE_F_PG_NO_READ))
-             == pVCpu->iem.s.CodeTlb.uTlbPhysRev)
+        if (    (pTlbe->fFlagsAndPhysRev & (/*IEMTLBE_F_PHYS_REV |*/ IEMTLBE_F_NO_MAPPINGR3 | IEMTLBE_F_PG_NO_READ))
+             == /*pVCpu->iem.s.CodeTlb.uTlbPhysRev*/ 0U)
         {
             uint32_t const offPg = (GCPtrFirst & X86_PAGE_OFFSET_MASK);

trunk/src/VBox/VMM/VMMAll/IEMAllN8veRecompBltIn.cpp

@@ -81 +81 @@
     else
     {
-        IEM_DO_LONGJMP(pVCpu, VINF_IEM_REEXEC_BREAK);
+        AssertMsgFailed(("cs:rip=%04x:%08RX64\n", pVCpu->cpum.GstCtx.cs.Sel, pVCpu->cpum.GstCtx.rip));
+        IEM_DO_LONGJMP(pVCpu, VINF_SUCCESS);
     }
 }
@@ -96 +97 @@
     pVCpu->iem.s.offInstrNextByte = GUEST_PAGE_SIZE;
     iemOpcodeFetchBytesJmp(pVCpu, 0, NULL);
+    AssertMsg(pVCpu->iem.s.pbInstrBuf, ("cs:rip=%04x:%08RX64\n", pVCpu->cpum.GstCtx.cs.Sel, pVCpu->cpum.GstCtx.rip));
     return pVCpu->iem.s.pbInstrBuf ? pVCpu->iem.s.GCPhysInstrBuf : NIL_RTGCPHYS;
 }

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

@@ -3159 +3159 @@
         IEM_CATCH_LONGJMP_BEGIN(pVCpu, rcStrict);
         {
+            Assert(rcStrict != VINF_IEM_REEXEC_BREAK);
             pVCpu->iem.s.cLongJumps++;
 #ifdef VBOX_WITH_IEM_NATIVE_RECOMPILER_LONGJMP