/* $Id: mpnotification-r0drv-linux.c 100191 2023-06-16 08:04:11Z vboxsync $ */ /** @file * IPRT - Multiprocessor Event Notifications, Ring-0 Driver, Linux. */ /* * Copyright (C) 2008-2023 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 . * * 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 "the-linux-kernel.h" #include "internal/iprt.h" #if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86) # include #endif #include #include #include #include "r0drv/mp-r0drv.h" #if RTLNX_VER_MIN(4,10,0) static enum cpuhp_state g_rtR0MpOnline; /* * Linux 4.10 completely removed CPU notifiers. So let's switch to CPU hotplug * notification. */ static int rtR0MpNotificationLinuxOnline(unsigned int cpu) { RTCPUID idCpu = RTMpCpuIdFromSetIndex(cpu); rtMpNotificationDoCallbacks(RTMPEVENT_ONLINE, idCpu); return 0; } static int rtR0MpNotificationLinuxOffline(unsigned int cpu) { RTCPUID idCpu = RTMpCpuIdFromSetIndex(cpu); rtMpNotificationDoCallbacks(RTMPEVENT_OFFLINE, idCpu); return 0; } DECLHIDDEN(int) rtR0MpNotificationNativeInit(void) { int rc; IPRT_LINUX_SAVE_EFL_AC(); rc = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "vboxdrv:online", rtR0MpNotificationLinuxOnline, rtR0MpNotificationLinuxOffline); IPRT_LINUX_RESTORE_EFL_AC(); /* * cpuhp_setup_state_nocalls() returns a positive state number for * CPUHP_AP_ONLINE_DYN or -ENOSPC if there is no free slot available * (see cpuhp_reserve_state / definition of CPUHP_AP_ONLINE_DYN). */ AssertMsgReturn(rc > 0, ("%d\n", rc), RTErrConvertFromErrno(rc)); g_rtR0MpOnline = rc; return VINF_SUCCESS; } DECLHIDDEN(void) rtR0MpNotificationNativeTerm(void) { IPRT_LINUX_SAVE_EFL_AC(); cpuhp_remove_state_nocalls(g_rtR0MpOnline); IPRT_LINUX_RESTORE_EFL_AC(); } #elif RTLNX_VER_MIN(2,5,71) && defined(CONFIG_SMP) static int rtMpNotificationLinuxCallback(struct notifier_block *pNotifierBlock, unsigned long ulNativeEvent, void *pvCpu); /** * The notifier block we use for registering the callback. */ static struct notifier_block g_NotifierBlock = { .notifier_call = rtMpNotificationLinuxCallback, .next = NULL, .priority = 0 }; # ifdef CPU_DOWN_FAILED /** * The set of CPUs we've seen going offline recently. */ static RTCPUSET g_MpPendingOfflineSet; # endif /** * The native callback. * * @returns NOTIFY_DONE. * @param pNotifierBlock Pointer to g_NotifierBlock. * @param ulNativeEvent The native event. * @param pvCpu The cpu id cast into a pointer value. * * @remarks This can fire with preemption enabled and on any CPU. */ static int rtMpNotificationLinuxCallback(struct notifier_block *pNotifierBlock, unsigned long ulNativeEvent, void *pvCpu) { bool fProcessEvent = false; RTCPUID idCpu = (uintptr_t)pvCpu; NOREF(pNotifierBlock); /* * Note that redhat/CentOS ported _some_ of the FROZEN macros * back to their 2.6.18-92.1.10.el5 kernel but actually don't * use them. Thus we have to test for both CPU_TASKS_FROZEN and * the individual event variants. */ switch (ulNativeEvent) { /* * Pick up online events or failures to go offline. * Ignore failure events for CPUs we didn't see go offline. */ # ifdef CPU_DOWN_FAILED case CPU_DOWN_FAILED: # if defined(CPU_TASKS_FROZEN) && defined(CPU_DOWN_FAILED_FROZEN) case CPU_DOWN_FAILED_FROZEN: # endif if (!RTCpuSetIsMember(&g_MpPendingOfflineSet, idCpu)) break; /* fProcessEvents = false */ /* fall thru */ # endif case CPU_ONLINE: # if defined(CPU_TASKS_FROZEN) && defined(CPU_ONLINE_FROZEN) case CPU_ONLINE_FROZEN: # endif # ifdef CPU_DOWN_FAILED RTCpuSetDel(&g_MpPendingOfflineSet, idCpu); # endif fProcessEvent = true; break; /* * Pick the earliest possible offline event. * The only important thing here is that we get the event and that * it's exactly one. */ # ifdef CPU_DOWN_PREPARE case CPU_DOWN_PREPARE: # if defined(CPU_TASKS_FROZEN) && defined(CPU_DOWN_PREPARE_FROZEN) case CPU_DOWN_PREPARE_FROZEN: # endif fProcessEvent = true; # else case CPU_DEAD: # if defined(CPU_TASKS_FROZEN) && defined(CPU_DEAD_FROZEN) case CPU_DEAD_FROZEN: # endif /* Don't process CPU_DEAD notifications. */ # endif # ifdef CPU_DOWN_FAILED RTCpuSetAdd(&g_MpPendingOfflineSet, idCpu); # endif break; } if (!fProcessEvent) return NOTIFY_DONE; switch (ulNativeEvent) { # ifdef CPU_DOWN_FAILED case CPU_DOWN_FAILED: # if defined(CPU_TASKS_FROZEN) && defined(CPU_DOWN_FAILED_FROZEN) case CPU_DOWN_FAILED_FROZEN: # endif # endif case CPU_ONLINE: # if defined(CPU_TASKS_FROZEN) && defined(CPU_ONLINE_FROZEN) case CPU_ONLINE_FROZEN: # endif rtMpNotificationDoCallbacks(RTMPEVENT_ONLINE, idCpu); break; # ifdef CPU_DOWN_PREPARE case CPU_DOWN_PREPARE: # if defined(CPU_TASKS_FROZEN) && defined(CPU_DOWN_PREPARE_FROZEN) case CPU_DOWN_PREPARE_FROZEN: # endif rtMpNotificationDoCallbacks(RTMPEVENT_OFFLINE, idCpu); break; # endif } return NOTIFY_DONE; } DECLHIDDEN(int) rtR0MpNotificationNativeInit(void) { int rc; IPRT_LINUX_SAVE_EFL_AC(); # ifdef CPU_DOWN_FAILED RTCpuSetEmpty(&g_MpPendingOfflineSet); # endif rc = register_cpu_notifier(&g_NotifierBlock); IPRT_LINUX_RESTORE_EFL_AC(); AssertMsgReturn(!rc, ("%d\n", rc), RTErrConvertFromErrno(rc)); return VINF_SUCCESS; } DECLHIDDEN(void) rtR0MpNotificationNativeTerm(void) { IPRT_LINUX_SAVE_EFL_AC(); unregister_cpu_notifier(&g_NotifierBlock); IPRT_LINUX_RESTORE_EFL_AC(); } #else /* Not supported / Not needed */ DECLHIDDEN(int) rtR0MpNotificationNativeInit(void) { return VINF_SUCCESS; } DECLHIDDEN(void) rtR0MpNotificationNativeTerm(void) { } #endif /* Not supported / Not needed */