Changeset 65501 in vbox for trunk/src/VBox/VMM

Timestamp:

Jan 28, 2017 10:36:58 PM (8 years ago)

Author:

vboxsync

Message:

IEM: some cmpxchg16b notes.

Location:

trunk/src/VBox/VMM

Files:

• VMMAll/IEMAllCImpl.cpp.h (modified) (1 diff)
• VMMAll/IEMAllInstructions.cpp.h (modified) (1 diff)
• include/IEMInternal.h (modified) (1 diff)

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

@@ -6362 +6362 @@
 
 
+/**
+ * Implements 'CMPXCHG16B' fallback using rendezvous.
+ */
+IEM_CIMPL_DEF_4(iemCImpl_cmpxchg16b_fallback_rendezvous, PRTUINT128U, pu128Dst, PRTUINT128U, pu64RaxRdx,
+                PRTUINT128U, pu64RbxRcx, uint32_t *, pEFlags)
+{
+    RT_NOREF(pVCpu, cbInstr, pu128Dst, pu64RaxRdx, pu64RbxRcx, pEFlags);
+#ifdef IN_RING3
+    /** @todo VMMR3EmtRendezvous() */
+    return VERR_NOT_IMPLEMENTED;
+#else
+    return VINF_EM_RAW_EMULATE_INSTR;
+#endif
+}
+
 
 /**

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

@@ -6833 +6833 @@
     if (IEM_GET_GUEST_CPU_FEATURES(pVCpu)->fMovCmpXchg16b)
     {
+#if 1
         RT_NOREF(bRm);
         IEMOP_BITCH_ABOUT_STUB();
         return VERR_IEM_INSTR_NOT_IMPLEMENTED;
+#else
+        IEM_MC_BEGIN(4, 3);
+        IEM_MC_ARG(PRTUINT128U, pu128MemDst,     0);
+        IEM_MC_ARG(PRTUINT128U, pu128RaxRdx,     1);
+        IEM_MC_ARG(PRTUINT128U, pu128RbxRcx,     2);
+        IEM_MC_ARG_LOCAL_EFLAGS(pEFlags, EFlags, 3);
+        IEM_MC_LOCAL(RTUINT128U, u128RaxRdx);
+        IEM_MC_LOCAL(RTUINT128U, u128RbxRcx);
+        IEM_MC_LOCAL(RTGCPTR, GCPtrEffDst);
+
+        IEM_MC_CALC_RM_EFF_ADDR(GCPtrEffDst, bRm, 0);
+        IEMOP_HLP_DONE_DECODING();
+        IEM_MC_MEM_MAP(pu128MemDst, IEM_ACCESS_DATA_RW, pVCpu->iem.s.iEffSeg, GCPtrEffDst, 0 /*arg*/);
+
+        IEM_MC_FETCH_GREG_U64(u128RaxRdx.s.Lo, X86_GREG_xAX);
+        IEM_MC_FETCH_GREG_U64(u128RaxRdx.s.Hi, X86_GREG_xDX);
+        IEM_MC_REF_LOCAL(pu128RaxRdx, u128RaxRdx);
+
+        IEM_MC_FETCH_GREG_U64(u128RbxRcx.s.Lo, X86_GREG_xBX);
+        IEM_MC_FETCH_GREG_U64(u128RbxRcx.s.Hi, X86_GREG_xCX);
+        IEM_MC_REF_LOCAL(pu128RbxRcx, u128RbxRcx);
+
+        IEM_MC_FETCH_EFLAGS(EFlags);
+# ifdef RT_ARCH_AMD64
+        if (IEM_GET_HOST_CPU_FEATURES(pVCpu)->fMovCmpXchg16b)
+        {
+            if (!(pVCpu->iem.s.fPrefixes & IEM_OP_PRF_LOCK))
+                IEM_MC_CALL_VOID_AIMPL_4(iemAImpl_cmpxchg16b, pu128MemDst, pu128RaxRdx, pu128RbxRcx, pEFlags);
+            else
+                IEM_MC_CALL_VOID_AIMPL_4(iemAImpl_cmpxchg16b_locked, pu128MemDst, pu128RaxRdx, pu128RbxRcx, pEFlags);
+        }
+        else
+# endif
+        {
+            /* Note! The fallback for 32-bit systems and systems without CX16 is to use
+                     SSE instructions for 16-byte loads and stores.  Since these aren't
+                     atomic and there are cycles between the loading and storing, this
+                     only works correctly in UNI CPU guests.  If guest SMP is active
+                     we have no choice but to use a rendezvous callback here.  Sigh. */
+            IEM_MC_ACTUALIZE_SSE_STATE_FOR_READ(); /* HACK ALERT! */
+            if (pVCpu->CTX_SUFF(pVM)->cCpus == 1)
+                IEM_MC_CALL_VOID_AIMPL_4(iemAImpl_cmpxchg16b_fallback_sse, pu128MemDst, pu128RaxRdx, pu128RbxRcx, pEFlags);
+            else
+                IEM_MC_CALL_CIMPL_4(iemCImpl_cmpxchg16b_fallback_rendezvous, pu128MemDst, pu128RaxRdx, pu128RbxRcx, pEFlags);
+        }
+
+        IEM_MC_MEM_COMMIT_AND_UNMAP(pu128MemDst, IEM_ACCESS_DATA_RW);
+        IEM_MC_COMMIT_EFLAGS(EFlags);
+        IEM_MC_IF_EFL_BIT_NOT_SET(X86_EFL_ZF)
+            IEM_MC_STORE_GREG_U64(X86_GREG_xAX, u128RaxRdx.s.Lo);
+            IEM_MC_STORE_GREG_U64(X86_GREG_xDX, u128RaxRdx.s.Hi);
+        IEM_MC_ENDIF();
+        IEM_MC_ADVANCE_RIP();
+
+        IEM_MC_END();
+        return VINF_SUCCESS;
+#endif
     }
     Log(("cmpxchg16b -> #UD\n"));

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

@@ -1102 +1102 @@
 IEM_DECL_IMPL_DEF(void, iemAImpl_cmpxchg8b_locked,(uint64_t *pu64Dst, PRTUINT64U pu64EaxEdx, PRTUINT64U pu64EbxEcx,
                                                    uint32_t *pEFlags));
-IEM_DECL_IMPL_DEF(void, iemAImpl_cmpxchg16b,(PRTUINT128U *pu128Dst, PRTUINT128U pu64RaxRdx, PRTUINT128U pu64RbxRcx,
+IEM_DECL_IMPL_DEF(void, iemAImpl_cmpxchg16b,(PRTUINT128U pu128Dst, PRTUINT128U pu64RaxRdx, PRTUINT128U pu64RbxRcx,
                                              uint32_t *pEFlags));
-IEM_DECL_IMPL_DEF(void, iemAImpl_cmpxchg16b_locked,(PRTUINT128U *pu128Dst, PRTUINT128U pu64RaxRdx, PRTUINT128U pu64RbxRcx,
+IEM_DECL_IMPL_DEF(void, iemAImpl_cmpxchg16b_locked,(PRTUINT128U pu128Dst, PRTUINT128U pu64RaxRdx, PRTUINT128U pu64RbxRcx,
                                                     uint32_t *pEFlags));
+IEM_DECL_IMPL_DEF(void, iemAImpl_cmpxchg16b_fallback_sse,(PRTUINT128U pu128Dst, PRTUINT128U pu64RaxRdx,
+                                                          PRTUINT128U pu64RbxRcx, uint32_t *pEFlags));
 /** @} */