Changeset 97156 in vbox

Timestamp:

Oct 14, 2022 12:10:26 PM (2 years ago)

Author:

vboxsync

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

154129

Message:

IEM: Quick fix to support PC/AT compatible math exception handling, analogous to what we do in HM. Required for DOS, OS/2, and other old guests.

File:

• trunk/src/VBox/VMM/VMMAll/IEMAll.cpp (modified) (1 diff)

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

@@ -4171 +4171 @@
 VBOXSTRICTRC iemRaiseMathFault(PVMCPUCC pVCpu)
 {
-    return iemRaiseXcptOrInt(pVCpu, 0, X86_XCPT_MF, IEM_XCPT_FLAGS_T_CPU_XCPT, 0, 0);
+    if (pVCpu->cpum.GstCtx.cr0 & X86_CR0_NE)
+        return iemRaiseXcptOrInt(pVCpu, 0, X86_XCPT_MF, IEM_XCPT_FLAGS_T_CPU_XCPT, 0, 0);
+    else
+    {
+        /* Convert a #MF into a FERR -> IRQ 13. See @bugref{6117}. */
+        PDMIsaSetIrq(pVCpu->CTX_SUFF(pVM), 13 /* u8Irq */, 1 /* u8Level */, 0 /* uTagSrc */);
+        iemRegUpdateRipAndClearRF(pVCpu);
+        return VINF_SUCCESS;
+    }
 }