Changeset 47673 in vbox for trunk

Timestamp:

Aug 12, 2013 2:03:08 PM (11 years ago)

Author:

vboxsync

Message:

HMVMXR0: Fixed copy&past from SVM code with fDr6=false in CPUMR0DebugStateMaybeSaveGuestAndRestoreHost call, causing DR6 to be lost upon ring-3 returns. I also think we must intercept #DB when doing lazy DRx loading, otherwise the #DB will update the host DR6 and the guess will be missing the debug event.

File:

• trunk/src/VBox/VMM/VMMR0/HMVMXR0.cpp (modified) (4 diffs)

trunk/src/VBox/VMM/VMMR0/HMVMXR0.cpp

@@ -3380 +3380 @@
         }
         /*
-         * If no debugging enabled, we'll lazy load DR0-3.
+         * If no debugging enabled, we'll lazy load DR0-3.  Unlike on AMD-V, we
+         * must intercept #DB in order to maintain a correct DR6 guest value.
          */
         else if (!CPUMIsGuestDebugStateActive(pVCpu))
+        {
             fInterceptMovDRx = true;
+            fInterceptDB = true;
+        }
 
         rc = VMXWriteVmcs32(VMX_VMCS_GUEST_DR7, pMixedCtx->dr[7]);
@@ -6037 +6041 @@
 
     /* Restore host debug registers if necessary and resync on next R0 reentry. */
-    if (CPUMIsGuestDebugStateActive(pVCpu))
-    {
-        CPUMR0DebugStateMaybeSaveGuestAndRestoreHost(pVCpu, false /* save DR6 */);
+#ifdef VBOX_STRICT
+    if (CPUMIsHyperDebugStateActive(pVCpu))
+        Assert(pVCpu->hm.s.vmx.u32ProcCtls & VMX_VMCS_CTRL_PROC_EXEC_MOV_DR_EXIT);
+#endif
+    if (CPUMR0DebugStateMaybeSaveGuestAndRestoreHost(pVCpu, true /* save DR6 */))
         pVCpu->hm.s.fContextUseFlags |= HM_CHANGED_GUEST_DEBUG;
-    }
-    else if (CPUMIsHyperDebugStateActive(pVCpu))
-    {
-        CPUMR0DebugStateMaybeSaveGuestAndRestoreHost(pVCpu, false /* save DR6 */);
-        Assert(pVCpu->hm.s.vmx.u32ProcCtls & VMX_VMCS_CTRL_PROC_EXEC_MOV_DR_EXIT);
-    }
     Assert(!CPUMIsGuestDebugStateActive(pVCpu));
     Assert(!CPUMIsHyperDebugStateActive(pVCpu));
@@ -9373 +9373 @@
         && !CPUMIsHyperDebugStateActive(pVCpu))
     {
-        /* Don't intercept MOV DRx. */
+        /* Don't intercept MOV DRx and #DB any more. */
         pVCpu->hm.s.vmx.u32ProcCtls &= ~VMX_VMCS_CTRL_PROC_EXEC_MOV_DR_EXIT;
         rc = VMXWriteVmcs32(VMX_VMCS32_CTRL_PROC_EXEC, pVCpu->hm.s.vmx.u32ProcCtls);
         AssertRCReturn(rc, rc);
+
+        if (!pVCpu->hm.s.vmx.RealMode.fRealOnV86Active)
+        {
+#ifndef HMVMX_ALWAYS_TRAP_ALL_XCPTS
+            pVCpu->hm.s.vmx.u32XcptBitmap &= ~RT_BIT(X86_XCPT_DB);
+            rc = VMXWriteVmcs32(VMX_VMCS32_CTRL_EXCEPTION_BITMAP, pVCpu->hm.s.vmx.u32XcptBitmap);
+            AssertRCReturn(rc, rc);
+#endif
+        }
 
         /* Save the host & load the guest debug state, restart execution of the MOV DRx instruction. */
@@ -9621 +9630 @@
     HMVMX_VALIDATE_EXIT_XCPT_HANDLER_PARAMS();
     STAM_COUNTER_INC(&pVCpu->hm.s.StatExitGuestDB);
+    Log6(("XcptDB\n"));
 
     /*