Changeset 10858 in vbox for trunk/src/VBox/VMM

Timestamp:

Jul 24, 2008 4:21:42 PM (17 years ago)

Author:

vboxsync

Message:

We can't rely on #NM handling in kernel mode, so do what we did before (change cr0, save host, restore guest)

File:

• trunk/src/VBox/VMM/VMMR0/CPUMR0.cpp (modified) (4 diffs)

trunk/src/VBox/VMM/VMMR0/CPUMR0.cpp

@@ -163 +163 @@
         break;
     }
+
+#ifndef CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE
+    uint64_t oldMsrEFERHost;
+        uint32_t oldCR0 = ASMGetCR0(); 
+
+    /* Clear MSR_K6_EFER_FFXSR or else we'll be unable to save/restore the XMM state with fxsave/fxrstor. */
+    if (pVM->cpum.s.CPUFeaturesExt.edx & X86_CPUID_AMD_FEATURE_EDX_FFXSR)
+    {
+        /* @todo Do we really need to read this every time?? The host could change this on the fly though. */
+        oldMsrEFERHost = ASMRdMsr(MSR_K6_EFER);
+
+        if (oldMsrEFERHost & MSR_K6_EFER_FFXSR)
+        {
+            ASMWrMsr(MSR_K6_EFER, oldMsrEFERHost & ~MSR_K6_EFER_FFXSR);
+            pVM->cpum.s.fUseFlags |= CPUM_MANUAL_XMM_RESTORE;
+        }
+    }
+
+    /* If we sync the FPU/XMM state on-demand, then we can continue execution as if nothing has happened. */ 
+    int rc = CPUMHandleLazyFPU(pVM);
+    AssertRC(rc);
+    Assert(CPUMIsGuestFPUStateActive(pVM)); 
+
+    /* Restore EFER MSR */
+    if (pVM->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
+        ASMWrMsr(MSR_K6_EFER, oldMsrEFERHost);
+
+        /* CPUMHandleLazyFPU could have changed CR0; restore it. */ 
+    ASMSetCR0(oldCR0); 
+#else
     /* Save the FPU control word and MXCSR, so we can restore the properly afterwards. 
      * We don't want the guest to be able to trigger floating point/SSE exceptions on the host.
@@ -188 +218 @@
         }
     }
+#endif
 
     pVM->cpum.s.fUseFlags |= CPUM_USED_FPU;
@@ -207 +238 @@
     AssertReturn((pVM->cpum.s.fUseFlags & CPUM_USED_FPU), VINF_SUCCESS);
 
+#ifndef CPUM_CAN_HANDLE_NM_TRAPS_IN_KERNEL_MODE
+    uint64_t oldMsrEFERHost;
+
+    /* Clear MSR_K6_EFER_FFXSR or else we'll be unable to save/restore the XMM state with fxsave/fxrstor. */
+    if (pVM->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
+    {
+        oldMsrEFERHost = ASMRdMsr(MSR_K6_EFER);
+        ASMWrMsr(MSR_K6_EFER, oldMsrEFERHost & ~MSR_K6_EFER_FFXSR);
+    }
+    CPUMRestoreHostFPUState(pVM);
+
+    /* Restore EFER MSR */
+    if (pVM->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
+        ASMWrMsr(MSR_K6_EFER, oldMsrEFERHost | MSR_K6_EFER_FFXSR);
+
+#else
     CPUMSaveFPUAsm(pCtx);
     if (pVM->cpum.s.fUseFlags & CPUM_MANUAL_XMM_RESTORE)
@@ -219 +266 @@
     if (pVM->cpum.s.CPUFeatures.edx.u1SSE)
         CPUMSetMXCSR(pVM->cpum.s.Host.fpu.MXCSR);
+#endif
 
     pVM->cpum.s.fUseFlags &= ~(CPUM_USED_FPU|CPUM_MANUAL_XMM_RESTORE);