Changeset 86191 in vbox for trunk/src/VBox

Timestamp:

Sep 21, 2020 9:59:04 AM (4 years ago)

Author:

vboxsync

Message:

Runtime/mp-r0drv-nt.cpp: Dynamically determine the size of the KAFFINITY_EX structure as it is not static across Windows versions (increased lately with W10 20H2) [2nd attempt]

File:

• trunk/src/VBox/Runtime/r0drv/nt/mp-r0drv-nt.cpp (modified) (3 diffs)

trunk/src/VBox/Runtime/r0drv/nt/mp-r0drv-nt.cpp

@@ -122 +122 @@
 /** The handle of the rtR0NtMpProcessorChangeCallback registration. */
 static PVOID                            g_pvMpCpuChangeCallback = NULL;
+/** Size of the KAFFINITY_EX structure.
+ * This increased from 20 to 32 bitmap words in the 2020 H2 windows 10 release
+ * (i.e. 1280 to 2048 CPUs).  We expect this to increase in the future. */
+static size_t                           g_cbRtMpNtKaffinityEx = RT_UOFFSETOF(KAFFINITY_EX, Bitmap)
+                                                              + RT_SIZEOFMEMB(KAFFINITY_EX, Bitmap[0]) * 256;
+/** The size value of the KAFFINITY_EX structure. */
+static uint16_t                         g_cRtMpNtKaffinityExEntries = 256;
 
 
@@ -598 +605 @@
         && g_pfnrtKeGetProcessorIndexFromNumber)
     {
-        g_pfnrtMpPokeCpuWorker = rtMpPokeCpuUsingHalRequestIpiW7Plus;
-        DbgPrint("IPRT: RTMpPoke => rtMpPokeCpuUsingHalRequestIpiW7Plus\n");
-    }
-    else if (pOsVerInfo->uMajorVer >= 6 && g_pfnrtKeIpiGenericCall)
+        /* Determine the real size of the KAFFINITY_EX structure. */
+        size_t const  cbAffinity = _8K;
+        PKAFFINITY_EX pAffinity  = (PKAFFINITY_EX)RTMemAllocZ(cbAffinity);
+        AssertReturn(pAffinity, VERR_NO_MEMORY);
+        size_t const cMaxEntries = (cbAffinity - RT_UOFFSETOF(KAFFINITY_EX, Bitmap[0])) / sizeof(pAffinity->Bitmap[0]);
+        g_pfnrtKeInitializeAffinityEx(pAffinity);
+        if (pAffinity->Size > 1 && pAffinity->Size <= cMaxEntries)
+        {
+            g_cRtMpNtKaffinityExEntries = pAffinity->Size;
+            g_cbRtMpNtKaffinityEx       = pAffinity->Size * sizeof(pAffinity->Bitmap[0]) + RT_UOFFSETOF(KAFFINITY_EX, Bitmap[0]);
+            g_pfnrtMpPokeCpuWorker      = rtMpPokeCpuUsingHalRequestIpiW7Plus;
+            RTMemFree(pAffinity);
+            DbgPrint("IPRT: RTMpPoke => rtMpPokeCpuUsingHalRequestIpiW7Plus\n");
+            return VINF_SUCCESS;
+        }
+        DbgPrint("IPRT: RTMpPoke can't use rtMpPokeCpuUsingHalRequestIpiW7Plus! pAffinity->Size=%u\n", pAffinity->Size);
+        AssertReleaseMsg(pAffinity->Size <= cMaxEntries, ("%#x\n", pAffinity->Size)); /* stack is toast if larger (32768 CPUs). */
+        RTMemFree(pAffinity);
+    }
+
+    if (pOsVerInfo->uMajorVer >= 6 && g_pfnrtKeIpiGenericCall)
     {
         DbgPrint("IPRT: RTMpPoke => rtMpPokeCpuUsingBroadcastIpi\n");
@@ -1861 +1885 @@
 {
     /* idCpu is an HAL processor index, so we can use it directly. */
-    KAFFINITY_EX Target;
-    g_pfnrtKeInitializeAffinityEx(&Target);
-    g_pfnrtKeAddProcessorAffinityEx(&Target, idCpu);
-
-    g_pfnrtHalRequestIpiW7Plus(0, &Target);
+    PKAFFINITY_EX pTarget = (PKAFFINITY_EX)alloca(g_cbRtMpNtKaffinityEx);
+    pTarget->Size = g_cRtMpNtKaffinityExEntries; /* (just in case KeInitializeAffinityEx starts using it) */
+    g_pfnrtKeInitializeAffinityEx(pTarget);
+    g_pfnrtKeAddProcessorAffinityEx(pTarget, idCpu);
+
+    g_pfnrtHalRequestIpiW7Plus(0, pTarget);
     return VINF_SUCCESS;
 }