Changeset 23513 in vbox for trunk/src/VBox

Timestamp:

Oct 2, 2009 1:21:27 PM (16 years ago)

Author:

vboxsync

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

53152

Message:

PGMSavedState: MMIO2 optimizations in the works.

Location:

trunk/src/VBox/VMM

Files:

• PGMInternal.h (modified) (3 diffs)
• PGMSavedState.cpp (modified) (8 diffs)
• testcase/tstCompressionBenchmark.cpp (modified) (2 diffs)

trunk/src/VBox/VMM/PGMInternal.h

@@ -41 +41 @@
 #include <iprt/avl.h>
 #include <iprt/critsect.h>
+#include <iprt/sha.h>
 
 
@@ -1256 +1257 @@
 
 /**
+ * Live save per page data for an MMIO2 page.
+ *
+ * Not using PGMLIVESAVEPAGE here because we cannot use normal write monitoring
+ * of MMIO2 pages.  The current approach is using some optimisitic SHA-1 +
+ * CRC-32 for detecting changes as well as special handling of zero pages.  This
+ * is a TEMPORARY measure which isn't perfect, but hopefully it is good enough
+ * for speeding things up.  (We're using SHA-1 and not SHA-256 or SHA-512
+ * because of speed (2.5x and 6x slower).)
+ *
+ * @todo Implement dirty MMIO2 page reporting that can be enabled during live
+ *       save but normally is disabled.  Since we can write monitore guest
+ *       accesses on our own, we only need this for host accesses.  Shouldn't be
+ *       too difficult for DevVGA, VMMDev might be doable, the planned
+ *       networking fun will be fun since it involves ring-0.
+ */
+typedef struct PGMLIVESAVEMMIO2PAGE
+{
+    /** Set if the page is considered dirty. */
+    bool        fDirty;
+    /** The number of scans this page has remained unchanged for.
+     * Only updated for dirty pages. */
+    uint8_t     cUnchangedScans;
+   /** Whether this page was zero at the last scan. */
+    bool        fZero;
+     /** Alignment padding. */
+    uint8_t     u8Padding;
+    /** CRC-32 for the first half of the page.
+     * This is used together with u32CrcH2 to quickly detect changes in the page
+     * during the non-final passes.  */
+    uint32_t    u32CrcH1;
+    /** CRC-32 for the second half of the page. */
+    uint32_t    u32CrcH2;
+    /** SHA-1 for the saved page.
+     * This is used in the final pass to skip pages without changes. */
+    uint8_t     abSha1Saved[RTSHA1_HASH_SIZE];
+} PGMLIVESAVEMMIO2PAGE;
+/** Pointer to a live save status data for an MMIO2 page. */
+typedef PGMLIVESAVEMMIO2PAGE *PPGMLIVESAVEMMIO2PAGE;
+
+/**
  * A registered MMIO2 (= Device RAM) range.
  *
@@ -1287 +1328 @@
     /** The saved state range ID. */
     uint8_t                             idSavedState;
-#if HC_ARCH_BITS != 32
     /** Alignment padding for putting the ram range on a PGMPAGE alignment boundrary. */
-    uint8_t                             abAlignemnt[HC_ARCH_BITS == 32 ? 0 : 4];
-#endif
+    uint8_t                             abAlignemnt[HC_ARCH_BITS == 32 ? 12 : 12];
+    /** Live save per page tracking data. */
+    PPGMLIVESAVEMMIO2PAGE               paLSPages;
     /** The associated RAM range. */
     PGMRAMRANGE                         RamRange;

trunk/src/VBox/VMM/PGMSavedState.cpp

@@ -90 +90 @@
 /** @} */
 
+/** The CRC-32 for a zero half page. */
+#define PGM_STATE_CRC32_ZERO_HALF_PAGE  UINT32_C(0xf1e8ba9e)
+
 
 /*******************************************************************************
@@ -207 +210 @@
     /*
      * Initialize the live save tracking in the MMIO2 ranges.
+     * ASSUME nothing changes here.
      */
     pgmLock(pVM);
     for (PPGMMMIO2RANGE pMmio2 = pVM->pgm.s.pMmio2RangesR3; pMmio2; pMmio2 = pMmio2->pNextR3)
     {
-        uint32_t const  cPages   = pMmio2->RamRange.cb >> PAGE_SHIFT;
-
-#if 0 /** @todo MMIO2 dirty page tracking for live save. */
+        uint32_t const  cPages = pMmio2->RamRange.cb >> PAGE_SHIFT;
+        pgmUnlock(pVM);
+
+        PPGMLIVESAVEMMIO2PAGE paLSPages = (PPGMLIVESAVEMMIO2PAGE)MMR3HeapAllocZ(pVM, MM_TAG_PGM, sizeof(PGMLIVESAVEMMIO2PAGE) * cPages);
+        if (!paLSPages)
+            return VERR_NO_MEMORY;
         for (uint32_t iPage = 0; iPage < cPages; iPage++)
         {
-        }
-#endif
+            paLSPages[iPage].fDirty          = true;
+            paLSPages[iPage].cUnchangedScans = 0;
+            paLSPages[iPage].fZero           = false;
+            paLSPages[iPage].u32CrcH1        = PGM_STATE_CRC32_ZERO_HALF_PAGE;
+            paLSPages[iPage].u32CrcH2        = PGM_STATE_CRC32_ZERO_HALF_PAGE;
+        }
+
+        pgmLock(pVM);
+        pMmio2->paLSPages = paLSPages;
         pVM->pgm.s.LiveSave.cMmio2Pages += cPages;
     }
@@ -767 +781 @@
  * @param   pSSM                The SSM handle.
  * @param   fLiveSave           Whether it's a live save or not.
- * @param   fFinalPass          Whether this is the final pass or not.
- */
-static int pgmR3SaveMmio2Pages(PVM pVM, PSSMHANDLE pSSM, bool fLiveSave, bool fFinalPass)
+ * @param   uPass               The pass number.
+ */
+static int pgmR3SaveMmio2Pages(PVM pVM, PSSMHANDLE pSSM, bool fLiveSave, uint32_t uPass)
 {
     int rc = VINF_SUCCESS;
     /** @todo implement live saving of MMIO2 pages. (Need some way of telling the
      *        device that we wish to know about changes.) */
-    if (fFinalPass)
-    {
+
+    if (uPass == SSM_PASS_FINAL)
+    {
+        /*
+         * Save all non-zero pages.
+         */
         pgmLock(pVM);
         for (PPGMMMIO2RANGE pMmio2 = pVM->pgm.s.pMmio2RangesR3;
@@ -814 +832 @@
  * @param   pSSM                The SSM handle.
  * @param   fLiveSave           Whether it's a live save or not.
- * @param   fFinalPass          Whether this is the final pass or not.
+ * @param   uPass               The pass number.
  */
 static int pgmR3SaveRamPages(PVM pVM, PSSMHANDLE pSSM, bool fLiveSave, uint32_t uPass)
@@ -1217 +1235 @@
         rc = pgmR3SaveShadowedRomPages(pVM, pSSM, true /*fLiveSave*/, false /*fFinalPass*/);
     if (RT_SUCCESS(rc))
-        rc = pgmR3SaveMmio2Pages(      pVM, pSSM, true /*fLiveSave*/, false /*fFinalPass*/);
+        rc = pgmR3SaveMmio2Pages(      pVM, pSSM, true /*fLiveSave*/, uPass);
     if (RT_SUCCESS(rc))
         rc = pgmR3SaveRamPages(        pVM, pSSM, true /*fLiveSave*/, uPass);
@@ -1369 +1387 @@
             rc = pgmR3SaveShadowedRomPages(    pVM, pSSM, true /*fLiveSave*/, true /*fFinalPass*/);
             if (RT_SUCCESS(rc))
-                rc = pgmR3SaveMmio2Pages(      pVM, pSSM, true /*fLiveSave*/, true /*fFinalPass*/);
+                rc = pgmR3SaveMmio2Pages(      pVM, pSSM, true /*fLiveSave*/, SSM_PASS_FINAL);
             if (RT_SUCCESS(rc))
                 rc = pgmR3SaveRamPages(        pVM, pSSM, true /*fLiveSave*/, SSM_PASS_FINAL);
@@ -1383 +1401 @@
                 rc = pgmR3SaveShadowedRomPages(pVM, pSSM, false /*fLiveSave*/, true /*fFinalPass*/);
             if (RT_SUCCESS(rc))
-                rc = pgmR3SaveMmio2Pages(      pVM, pSSM, false /*fLiveSave*/, true /*fFinalPass*/);
+                rc = pgmR3SaveMmio2Pages(      pVM, pSSM, false /*fLiveSave*/, SSM_PASS_FINAL);
             if (RT_SUCCESS(rc))
                 rc = pgmR3SaveRamPages(        pVM, pSSM, false /*fLiveSave*/, SSM_PASS_FINAL);
@@ -1501 +1519 @@
     } while (pCur);
 
+    /* Ditto for MMIO2 (ASSUME no runtime MMIO2 changes). */
+    for (PPGMMMIO2RANGE pMmio2 = pVM->pgm.s.pMmio2RangesR3; pMmio2; pMmio2 = pMmio2->pNextR3)
+    {
+        void *pvMmio2ToFree = pMmio2->paLSPages;
+        if (pvMmio2ToFree)
+        {
+            pMmio2->paLSPages = NULL;
+            pgmUnlock(pVM);
+            MMR3HeapFree(pvMmio2ToFree);
+            pgmLock(pVM);
+        }
+    }
+
+    /* Update PGM state. */
     pVM->pgm.s.LiveSave.fActive = false;
 

trunk/src/VBox/VMM/testcase/tstCompressionBenchmark.cpp

@@ -151 +151 @@
     RTPrintf("SHA-512   %'9u KB/s  %'15llu ns - %s\n", uSpeed, NanoTS, szDigest);
 }
+
 
 /**
@@ -631 +632 @@
      */
     RTPrintf("\n"
-             "tstCompressionBenchmark: Checksum/CRC - All In One\n");
+             "tstCompressionBenchmark: Hash/CRC - All In One\n");
     tstBenchmarkCRCsAllInOne(g_pabSrc, g_cbPages);
 
     RTPrintf("\n"
-             "tstCompressionBenchmark: Checksum/CRC - Page by Page\n");
+             "tstCompressionBenchmark: Hash/CRC - Page by Page\n");
     tstBenchmarkCRCsPageByPage(g_pabSrc, g_cbPages);
+
+    RTPrintf("\n"
+             "tstCompressionBenchmark: Hash/CRC - Zero Page Digest\n");
+    static uint8_t s_abZeroPg[PAGE_SIZE];
+    RT_ZERO(s_abZeroPg);
+    tstBenchmarkCRCsAllInOne(s_abZeroPg, PAGE_SIZE);
+
+    RTPrintf("\n"
+             "tstCompressionBenchmark: Hash/CRC - Zero Half Page Digest\n");
+    tstBenchmarkCRCsAllInOne(s_abZeroPg, PAGE_SIZE / 2);
 
     RTPrintf("tstCompressionBenchmark: END RESULTS\n");