Changeset 57126 in vbox

Timestamp:

Jul 30, 2015 10:17:57 AM (10 years ago)

Author:

vboxsync

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

101864

Message:

VMM: Optimizations for memory scanning, trying to make 'detect' run faster against 64-bit guest systems.

Location:

trunk/src/VBox/VMM

Files:

• Makefile.kmk (modified) (1 diff)
• VMMR3/PGMDbg.cpp (modified) (10 diffs)
• VMMR3/PGMR3DbgA.asm (added)

trunk/src/VBox/VMM/Makefile.kmk

@@ -180 +180 @@
         VMMR3/PGM.cpp \
         VMMR3/PGMDbg.cpp \
+        VMMR3/PGMR3DbgA.asm \
         VMMR3/PGMHandler.cpp \
         VMMR3/PGMMap.cpp \

trunk/src/VBox/VMM/VMMR3/PGMDbg.cpp

@@ -94 +94 @@
 
 
+/**
+ * Assembly scanning function.
+ *
+ * @returns Pointer to possible match or NULL.
+ * @param   pvHaystack      Pointer to what we search in.
+ * @param   cbHaystack      Number of bytes to search.
+ * @param   pvNeedle        Pointer to what we search for.
+ * @param   cbNeedle        Size of what we're searching for.
+ */
+typedef DECLCALLBACK(uint8_t const *) FNPGMR3DBGFIXEDMEMSCAN(void const *pvHaystack, uint32_t cbHaystack,
+                                                             void const *pvNeedle, size_t cbNeedle);
+/** Pointer to an fixed size and step assembly scanner function. */
+typedef FNPGMR3DBGFIXEDMEMSCAN *PFNPGMR3DBGFIXEDMEMSCAN;
+
+
+/*******************************************************************************
+*   Internal Functions                                                         *
+*******************************************************************************/
+DECLASM(uint8_t const *) pgmR3DbgFixedMemScan8Wide8Step(void const *, uint32_t, void const *, size_t cbNeedle);
+DECLASM(uint8_t const *) pgmR3DbgFixedMemScan4Wide4Step(void const *, uint32_t, void const *, size_t cbNeedle);
+DECLASM(uint8_t const *) pgmR3DbgFixedMemScan2Wide2Step(void const *, uint32_t, void const *, size_t cbNeedle);
+DECLASM(uint8_t const *) pgmR3DbgFixedMemScan1Wide1Step(void const *, uint32_t, void const *, size_t cbNeedle);
+DECLASM(uint8_t const *) pgmR3DbgFixedMemScan4Wide1Step(void const *, uint32_t, void const *, size_t cbNeedle);
+DECLASM(uint8_t const *) pgmR3DbgFixedMemScan8Wide1Step(void const *, uint32_t, void const *, size_t cbNeedle);
+
 
 /**
@@ -470 +495 @@
  */
 static bool pgmR3DbgScanPage(const uint8_t *pbPage, int32_t *poff, uint32_t cb, uint32_t uAlign,
-                             const uint8_t *pabNeedle, size_t cbNeedle,
+                             const uint8_t *pabNeedle, size_t cbNeedle, PFNPGMR3DBGFIXEDMEMSCAN pfnFixedMemScan,
                              uint8_t *pabPrev, size_t *pcbPrev)
 {
@@ -517 +542 @@
      */
     const uint8_t *pb = pbPage + *poff;
-    const uint8_t *pbEnd = pb + cb;
+    const uint8_t * const pbEnd = pb + cb;
     for (;;)
     {
-        pb = pgmR3DbgAlignedMemChr(pb, *pabNeedle, cb, uAlign);
+        AssertMsg(((uintptr_t)pb & (uAlign - 1)) == 0, ("%#p %#x\n", pb, uAlign));
+        if (pfnFixedMemScan)
+            pb = pfnFixedMemScan(pb, cb, pabNeedle, cbNeedle);
+        else
+            pb = pgmR3DbgAlignedMemChr(pb, *pabNeedle, cb, uAlign);
         if (!pb)
             break;
@@ -554 +583 @@
     return false;
 }
+
+
+static void pgmR3DbgSelectMemScanFunction(PFNPGMR3DBGFIXEDMEMSCAN *ppfnMemScan, uint32_t GCPhysAlign, size_t cbNeedle)
+{
+    *ppfnMemScan = NULL;
+    switch (GCPhysAlign)
+    {
+        case 1:
+            if (cbNeedle >= 8)
+                *ppfnMemScan = pgmR3DbgFixedMemScan8Wide1Step;
+            else if (cbNeedle >= 4)
+                *ppfnMemScan = pgmR3DbgFixedMemScan8Wide1Step;
+            else
+                *ppfnMemScan = pgmR3DbgFixedMemScan1Wide1Step;
+            break;
+        case 2:
+            if (cbNeedle >= 2)
+                *ppfnMemScan = pgmR3DbgFixedMemScan2Wide2Step;
+            break;
+        case 4:
+            if (cbNeedle >= 4)
+                *ppfnMemScan = pgmR3DbgFixedMemScan4Wide4Step;
+            break;
+        case 8:
+            if (cbNeedle >= 8)
+                *ppfnMemScan = pgmR3DbgFixedMemScan8Wide8Step;
+            break;
+    }
+}
+
 
 
@@ -621 +680 @@
                                ? GCPhys + cbRange - 1
                                : ~(RTGCPHYS)0;
+
+    PFNPGMR3DBGFIXEDMEMSCAN pfnMemScan;
+    pgmR3DbgSelectMemScanFunction(&pfnMemScan, (uint32_t)GCPhysAlign, cbNeedle);
 
     /*
@@ -677 +739 @@
                                               : (GCPhysLast & PAGE_OFFSET_MASK) + 1 - (uint32_t)offPage;
                             fRc = pgmR3DbgScanPage((uint8_t const *)pvPage, &offHit, cbSearch, (uint32_t)GCPhysAlign,
-                                                   pabNeedle, cbNeedle, &abPrev[0], &cbPrev);
+                                                   pabNeedle, cbNeedle, pfnMemScan, &abPrev[0], &cbPrev);
                         }
                         else
@@ -796 +858 @@
     uint32_t        offPage   = GCPtr & PAGE_OFFSET_MASK;
     GCPtr &= ~(RTGCPTR)PAGE_OFFSET_MASK;
+
+    PFNPGMR3DBGFIXEDMEMSCAN pfnMemScan;
+    pgmR3DbgSelectMemScanFunction(&pfnMemScan, (uint32_t)GCPtrAlign, cbNeedle);
+
+    uint32_t        cYieldCountDown = 4096;
+    pgmLock(pVM);
     for (;; offPage = 0)
     {
@@ -822 +890 @@
                                           : (GCPtrLast & PAGE_OFFSET_MASK) + 1 - (uint32_t)offPage;
                         fRc = pgmR3DbgScanPage((uint8_t const *)pvPage, &offHit, cbSearch, (uint32_t)GCPtrAlign,
-                                               pabNeedle, cbNeedle, &abPrev[0], &cbPrev);
+                                               pabNeedle, cbNeedle, pfnMemScan, &abPrev[0], &cbPrev);
                     }
                     else
@@ -831 +899 @@
                     {
                         *pGCPtrHit = GCPtr + offHit;
+                        pgmUnlock(pVM);
                         return VINF_SUCCESS;
                     }
@@ -905 +974 @@
         cPages -= cIncPages;
         GCPtr += (RTGCPTR)cIncPages << X86_PT_PAE_SHIFT;
-    }
+
+        /* Yield the PGM lock every now and then. */
+        if (!--cYieldCountDown)
+        {
+            PDMR3CritSectYield(&pVM->pgm.s.CritSectX);
+            cYieldCountDown = 4096;
+        }
+    }
+    pgmUnlock(pVM);
     return VERR_DBGF_MEM_NOT_FOUND;
 }