Changeset 15852 in vbox for trunk/src/VBox

Timestamp:

Jan 8, 2009 10:56:11 AM (16 years ago)

Author:

vboxsync

Message:

Another experiment with limiting the time spent in ring 0.

Location:

trunk/src/VBox/VMM

Files:

• HWACCMInternal.h (modified) (1 diff)
• VMM.cpp (modified) (1 diff)
• VMMR0/HWVMXR0.cpp (modified) (9 diffs)

trunk/src/VBox/VMM/HWACCMInternal.h

@@ -435 +435 @@
 typedef struct HWACCMCPU
 {
+    /** Time of entry into the ring 0 world switcher code. */
+    uint64_t                    u64TimeEntry;
+
     /** Old style FPU reporting trap mask override performed (optimization) */
     bool                        fFPUOldStyleOverride;

trunk/src/VBox/VMM/VMM.cpp

@@ -1426 +1426 @@
             LogRel((pVM->vmm.s.szRing0AssertMsg2));
             return VERR_VMM_RING0_ASSERTION;
+
+        /* 
+         * A forced switch to ring 0 for preemption purposes. 
+         */
+        case VMMCALLHOST_VM_R0_PREEMPT:
+            pVM->vmm.s.rcCallHost = VINF_SUCCESS;
+            break;
 
         default:

trunk/src/VBox/VMM/VMMR0/HWVMXR0.cpp

@@ -39 +39 @@
 #include <iprt/asm.h>
 #include <iprt/string.h>
+#include <iprt/time.h>
 #include "HWVMXR0.h"
 
@@ -1893 +1894 @@
     RTGCUINTPTR errCode, instrInfo;
     bool        fSyncTPR = false;
+    bool        fPreemptPending = false;
     PHWACCM_CPUINFO pCpu = 0;
     unsigned    cResume = 0;
@@ -1966 +1968 @@
     }
 #endif
+
+    /* Fetch the current time so we can bail out when necessary. */
+    pVCpu->hwaccm.s.u64TimeEntry = RTTimeNanoTS();
 
     /* We can jump to this point to resume execution after determining that a VM-exit is innocent.
@@ -1980 +1985 @@
 
     /* Safety precaution; looping for too long here can have a very bad effect on the host */
-    if (++cResume > HWACCM_MAX_RESUME_LOOPS)
+    if (    ++cResume > HWACCM_MAX_RESUME_LOOPS
+        ||  RTTimeNanoTS() - pVCpu->hwaccm.s.u64TimeEntry >= 2000000)
     {
         STAM_COUNTER_INC(&pVCpu->hwaccm.s.StatExitMaxResume);
@@ -2157 +2163 @@
     STAM_PROFILE_ADV_START(&pVCpu->hwaccm.s.StatExit1, v);
 
-    if (rc != VINF_SUCCESS)
+    if (VBOX_FAILURE(rc))
     {
         VMXR0ReportWorldSwitchError(pVM, pVCpu, rc, pCtx);
         goto end;
     }
+    if (rc == VINF_VMX_PREEMPT_PENDING)
+        fPreemptPending = true;
+
     /* Success. Query the guest state and figure out what has happened. */
 
@@ -2236 +2245 @@
     {
         rc = PDMApicSetTPR(pVM, pVM->hwaccm.s.vmx.pAPIC[0x80] >> 4);
+        AssertRC(rc);
+    }
+
+    if (fPreemptPending)
+    {
+        fPreemptPending = false;
+        rc = VMMR0CallHost(pVM, VMMCALLHOST_VM_R0_PREEMPT, 0);
         AssertRC(rc);
     }
@@ -3009 +3025 @@
 
     case VMX_EXIT_PREEMPTION_TIMER:     /* 52 VMX-preemption timer expired. The preemption timer counted down to zero. */
-#ifdef RT_OS_WINDOWS
         goto ResumeExecution;
-#else
-        break; /* enable interrupts again */
-#endif
 
     default:
@@ -3583 +3595 @@
     aParam[5] = 0;
 
-    if (pVM->hwaccm.s.vmx.msr.vmx_pin_ctls.n.allowed1 & VMX_VMCS_CTRL_PIN_EXEC_CONTROLS_PREEMPT_TIMER)
-    {
-        uint32_t uBit, val;
-
-        rc = VMXReadVMCS32(VMX_VMCS_CTRL_PIN_EXEC_CONTROLS, &val);
-        AssertRC(rc);
-        val  = val | VMX_VMCS_CTRL_PIN_EXEC_CONTROLS_PREEMPT_TIMER;
-        rc = VMXWriteVMCS(VMX_VMCS_CTRL_PIN_EXEC_CONTROLS, val);
-        AssertRC(rc);
-
-        uBit = MSR_IA32_VMX_MISC_PREEMPT_TSC_BIT(pVM->hwaccm.s.vmx.msr.vmx_misc);
-        val = 1000000 / RT_BIT(uBit);
-        VMXWriteVMCS(VMX_VMCS32_GUEST_PREEMPTION_TIMER_VALUE, val);
-    }
-
     rc = VMXR0Execute64BitsHandler(pVM, pVCpu, pCtx, pVM->hwaccm.s.pfnVMXGCStartVM64, 6, &aParam[0]);
-
-    if (pVM->hwaccm.s.vmx.msr.vmx_pin_ctls.n.allowed1 & VMX_VMCS_CTRL_PIN_EXEC_CONTROLS_PREEMPT_TIMER)
-    {
-        uint32_t val;
-
-        rc = VMXReadVMCS32(VMX_VMCS_CTRL_PIN_EXEC_CONTROLS, &val);
-        AssertRC(rc);
-        val  = val & ~VMX_VMCS_CTRL_PIN_EXEC_CONTROLS_PREEMPT_TIMER;
-        rc = VMXWriteVMCS(VMX_VMCS_CTRL_PIN_EXEC_CONTROLS, val);
-        AssertRC(rc);
-    }
 
 #ifdef DEBUG
@@ -3621 +3607 @@
 #endif
 
+    /* Check if we've been running too long. */
+    if (    rc == VINF_SUCCESS
+        &&  RTTimeNanoTS() - pVM->hwaccm.s.u64TimeEntry >= 2000000
+    {
+        return VINF_VMX_PREEMPT_PENDING;
+    }
     return rc;
 }