1 files changed, 148 insertions, 0 deletions
diff --git a/src/VBox/Runtime/generic/RTMpOnPair-generic.cpp b/src/VBox/Runtime/generic/RTMpOnPair-generic.cpp
new file mode 100644
index 00000000..f6000b0c
--- /dev/null
+++ b/src/VBox/Runtime/generic/RTMpOnPair-generic.cpp
@@ -0,0 +1,148 @@
+/* $Id: RTMpOnPair-generic.cpp $ */
+/** @file
+ * IPRT - RTMpOnPair, generic implementation using RTMpOnAll.
+ */
+
+/*
+ * Copyright (C) 2015-2023 Oracle and/or its affiliates.
+ *
+ * This file is part of VirtualBox base platform packages, as
+ * available from https://www.virtualbox.org.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, in version 3 of the
+ * License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses>.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
+ * in the VirtualBox distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ *
+ * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#include "internal/iprt.h"
+#include <iprt/mp.h>
+
+#include <iprt/asm.h>
+#include <iprt/assert.h>
+#include <iprt/err.h>
+
+
+/*********************************************************************************************************************************
+*   Structures and Typedefs                                                                                                      *
+*********************************************************************************************************************************/
+/**
+ * Argument package for the generic RTMpOnPair implemenetation.
+ */
+typedef struct RTMPONPAIRGENERIC
+{
+    RTCPUID             idCpu1;
+    RTCPUID             idCpu2;
+    PFNRTMPWORKER       pfnWorker;
+    void               *pvUser1;
+    void               *pvUser2;
+    /** Count of how many CPUs actually showed up. */
+    uint32_t volatile   cPresent;
+} RTMPONPAIRGENERIC;
+/** Pointer to the an argument package for the generic RTMpOnPair
+ *  implemenation. */
+typedef RTMPONPAIRGENERIC *PRTMPONPAIRGENERIC;
+
+
+/**
+ * @callback_method_impl{FNRTMPWORKER,
+ *      Used by RTMpOnPair to call the worker on the two specified CPUs.}
+ */
+static DECLCALLBACK(void) rtMpOnPairGenericWorker(RTCPUID idCpu, void *pvUser1, void *pvUser2)
+{
+    RT_NOREF(pvUser2);
+    PRTMPONPAIRGENERIC pArgs = (PRTMPONPAIRGENERIC)pvUser1;
+
+    /*
+     * Only the two choosen CPUs should call the worker function, count how
+     * many of them that showed up.
+     */
+    if (   idCpu == pArgs->idCpu1
+        || idCpu == pArgs->idCpu2)
+    {
+        ASMAtomicIncU32(&pArgs->cPresent);
+        pArgs->pfnWorker(idCpu, pArgs->pvUser1, pArgs->pvUser2);
+    }
+}
+
+
+RTDECL(int) RTMpOnPair(RTCPUID idCpu1, RTCPUID idCpu2, uint32_t fFlags, PFNRTMPWORKER pfnWorker, void *pvUser1, void *pvUser2)
+{
+    int rc;
+    AssertReturn(idCpu1 != idCpu2, VERR_INVALID_PARAMETER);
+    AssertReturn(!(fFlags & RTMPON_F_VALID_MASK), VERR_INVALID_FLAGS);
+    if ((fFlags & RTMPON_F_CONCURRENT_EXEC) && !RTMpOnAllIsConcurrentSafe())
+        return VERR_NOT_SUPPORTED;
+
+    /*
+     * Check that both CPUs are online before doing the broadcast call.
+     */
+    if (   RTMpIsCpuOnline(idCpu1)
+        && RTMpIsCpuOnline(idCpu2))
+    {
+        RTMPONPAIRGENERIC Args;
+        Args.idCpu1    = idCpu1;
+        Args.idCpu2    = idCpu2;
+        Args.pfnWorker = pfnWorker;
+        Args.pvUser1   = pvUser1;
+        Args.pvUser2   = pvUser2;
+        Args.cPresent  = 0;
+        rc = RTMpOnAll(rtMpOnPairGenericWorker, &Args, pvUser2);
+        if (RT_SUCCESS(rc))
+        {
+            /*
+             * Let's see if both of the CPUs showed up.
+             */
+            if (RT_LIKELY(Args.cPresent == 2))
+            { /* likely */ }
+            else if (Args.cPresent == 0)
+                rc = VERR_CPU_OFFLINE;
+            else if (Args.cPresent == 1)
+                rc = VERR_NOT_ALL_CPUS_SHOWED;
+            else
+            {
+                rc = VERR_CPU_IPE_1;
+                AssertMsgFailed(("cPresent=%#x\n", Args.cPresent));
+            }
+        }
+    }
+    /*
+     * A CPU must be present to be considered just offline.
+     */
+    else if (   RTMpIsCpuPresent(idCpu1)
+             && RTMpIsCpuPresent(idCpu2))
+        rc = VERR_CPU_OFFLINE;
+    else
+        rc = VERR_CPU_NOT_FOUND;
+    return rc;
+}
+
+
+RTDECL(bool) RTMpOnPairIsConcurrentExecSupported(void)
+{
+    return RTMpOnAllIsConcurrentSafe();
+}
+