/* $Id: VMReq.cpp 26491 2010-02-14 07:47:12Z vboxsync $ */ /** @file * VM - Virtual Machine */ /* * Copyright (C) 2006-2007 Sun Microsystems, Inc. * * This file is part of VirtualBox Open Source Edition (OSE), as * available from http://www.virtualbox.org. This file is free software; * you can redistribute it and/or modify it under the terms of the GNU * General Public License (GPL) as published by the Free Software * Foundation, in version 2 as it comes in the "COPYING" file of the * VirtualBox OSE distribution. VirtualBox OSE is distributed in the * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa * Clara, CA 95054 USA or visit http://www.sun.com if you need * additional information or have any questions. */ /******************************************************************************* * Header Files * *******************************************************************************/ #define LOG_GROUP LOG_GROUP_VM #include #include #include "VMInternal.h" #include #include #include #include #include #include #include #include #include #include #include /******************************************************************************* * Internal Functions * *******************************************************************************/ static int vmR3ReqProcessOneU(PUVM pUVM, PVMREQ pReq); /** * Allocate and queue a call request. * * If it's desired to poll on the completion of the request set cMillies * to 0 and use VMR3ReqWait() to check for completation. In the other case * use RT_INDEFINITE_WAIT. * The returned request packet must be freed using VMR3ReqFree(). * * @returns VBox status code. * Will not return VERR_INTERRUPTED. * @returns VERR_TIMEOUT if cMillies was reached without the packet being completed. * * @param pVM The VM handle. * @param idDstCpu The destination CPU(s). Either a specific CPU ID or * one of the following special values: * VMCPUID_ANY, VMCPUID_ANY_QUEUE, VMCPUID_ALL or VMCPUID_ALL_REVERSE. * @param ppReq Where to store the pointer to the request. * This will be NULL or a valid request pointer not matter what happends. * @param cMillies Number of milliseconds to wait for the request to * be completed. Use RT_INDEFINITE_WAIT to only * wait till it's completed. * @param fFlags A combination of the VMREQFLAGS values. * @param pfnFunction Pointer to the function to call. * @param cArgs Number of arguments following in the ellipsis. * @param ... Function arguments. * * @remarks See remarks on VMR3ReqCallVU. */ VMMR3DECL(int) VMR3ReqCall(PVM pVM, VMCPUID idDstCpu, PVMREQ *ppReq, RTMSINTERVAL cMillies, uint32_t fFlags, PFNRT pfnFunction, unsigned cArgs, ...) { va_list va; va_start(va, cArgs); int rc = VMR3ReqCallVU(pVM->pUVM, idDstCpu, ppReq, cMillies, fFlags, pfnFunction, cArgs, va); va_end(va); return rc; } /** * Convenience wrapper for VMR3ReqCallU. * * This assumes (1) you're calling a function that returns an VBox status code, * (2) that you want it's return code on success, and (3) that you wish to wait * for ever for it to return. * * @returns VBox status code. In the unlikely event that VMR3ReqCallVU fails, * its status code is return. Otherwise, the status of pfnFunction is * returned. * * @param pVM Pointer to the shared VM structure. * @param idDstCpu The destination CPU(s). Either a specific CPU ID or * one of the following special values: * VMCPUID_ANY, VMCPUID_ANY_QUEUE, VMCPUID_ALL or VMCPUID_ALL_REVERSE. * @param pfnFunction Pointer to the function to call. * @param cArgs Number of arguments following in the ellipsis. * @param ... Function arguments. * * @remarks See remarks on VMR3ReqCallVU. */ VMMR3DECL(int) VMR3ReqCallWait(PVM pVM, VMCPUID idDstCpu, PFNRT pfnFunction, unsigned cArgs, ...) { PVMREQ pReq; va_list va; va_start(va, cArgs); int rc = VMR3ReqCallVU(pVM->pUVM, idDstCpu, &pReq, RT_INDEFINITE_WAIT, VMREQFLAGS_VBOX_STATUS, pfnFunction, cArgs, va); va_end(va); if (RT_SUCCESS(rc)) rc = pReq->iStatus; VMR3ReqFree(pReq); return rc; } /** * Convenience wrapper for VMR3ReqCallU. * * This assumes (1) you're calling a function that returns an VBox status code, * (2) that you want it's return code on success, and (3) that you wish to wait * for ever for it to return. * * @returns VBox status code. In the unlikely event that VMR3ReqCallVU fails, * its status code is return. Otherwise, the status of pfnFunction is * returned. * * @param pUVM Pointer to the user mode VM structure. * @param idDstCpu The destination CPU(s). Either a specific CPU ID or * one of the following special values: * VMCPUID_ANY, VMCPUID_ANY_QUEUE, VMCPUID_ALL or VMCPUID_ALL_REVERSE. * @param pfnFunction Pointer to the function to call. * @param cArgs Number of arguments following in the ellipsis. * @param ... Function arguments. * * @remarks See remarks on VMR3ReqCallVU. */ VMMR3DECL(int) VMR3ReqCallWaitU(PUVM pUVM, VMCPUID idDstCpu, PFNRT pfnFunction, unsigned cArgs, ...) { PVMREQ pReq; va_list va; va_start(va, cArgs); int rc = VMR3ReqCallVU(pUVM, idDstCpu, &pReq, RT_INDEFINITE_WAIT, VMREQFLAGS_VBOX_STATUS, pfnFunction, cArgs, va); va_end(va); if (RT_SUCCESS(rc)) rc = pReq->iStatus; VMR3ReqFree(pReq); return rc; } /** * Convenience wrapper for VMR3ReqCallU. * * This assumes (1) you're calling a function that returns an VBox status code * and that you do not wish to wait for it to complete. * * @returns VBox status code returned by VMR3ReqCallVU. * * @param pVM Pointer to the shared VM structure. * @param idDstCpu The destination CPU(s). Either a specific CPU ID or * one of the following special values: * VMCPUID_ANY, VMCPUID_ANY_QUEUE, VMCPUID_ALL or VMCPUID_ALL_REVERSE. * @param pfnFunction Pointer to the function to call. * @param cArgs Number of arguments following in the ellipsis. * @param ... Function arguments. * * @remarks See remarks on VMR3ReqCallVU. */ VMMR3DECL(int) VMR3ReqCallNoWait(PVM pVM, VMCPUID idDstCpu, PFNRT pfnFunction, unsigned cArgs, ...) { va_list va; va_start(va, cArgs); int rc = VMR3ReqCallVU(pVM->pUVM, idDstCpu, NULL, 0, VMREQFLAGS_VBOX_STATUS | VMREQFLAGS_NO_WAIT, pfnFunction, cArgs, va); va_end(va); return rc; } /** * Convenience wrapper for VMR3ReqCallU. * * This assumes (1) you're calling a function that returns an VBox status code * and that you do not wish to wait for it to complete. * * @returns VBox status code returned by VMR3ReqCallVU. * * @param pUVM Pointer to the user mode VM structure. * @param idDstCpu The destination CPU(s). Either a specific CPU ID or * one of the following special values: * VMCPUID_ANY, VMCPUID_ANY_QUEUE, VMCPUID_ALL or VMCPUID_ALL_REVERSE. * @param pfnFunction Pointer to the function to call. * @param cArgs Number of arguments following in the ellipsis. * @param ... Function arguments. * * @remarks See remarks on VMR3ReqCallVU. */ VMMR3DECL(int) VMR3ReqCallNoWaitU(PUVM pUVM, VMCPUID idDstCpu, PFNRT pfnFunction, unsigned cArgs, ...) { va_list va; va_start(va, cArgs); int rc = VMR3ReqCallVU(pUVM, idDstCpu, NULL, 0, VMREQFLAGS_VBOX_STATUS | VMREQFLAGS_NO_WAIT, pfnFunction, cArgs, va); va_end(va); return rc; } /** * Convenience wrapper for VMR3ReqCallU. * * This assumes (1) you're calling a function that returns void, and (2) that * you wish to wait for ever for it to return. * * @returns VBox status code of VMR3ReqCallVU. * * @param pVM Pointer to the shared VM structure. * @param idDstCpu The destination CPU(s). Either a specific CPU ID or * one of the following special values: * VMCPUID_ANY, VMCPUID_ANY_QUEUE, VMCPUID_ALL or VMCPUID_ALL_REVERSE. * @param pfnFunction Pointer to the function to call. * @param cArgs Number of arguments following in the ellipsis. * @param ... Function arguments. * * @remarks See remarks on VMR3ReqCallVU. */ VMMR3DECL(int) VMR3ReqCallVoidWait(PVM pVM, VMCPUID idDstCpu, PFNRT pfnFunction, unsigned cArgs, ...) { PVMREQ pReq; va_list va; va_start(va, cArgs); int rc = VMR3ReqCallVU(pVM->pUVM, idDstCpu, &pReq, RT_INDEFINITE_WAIT, VMREQFLAGS_VOID, pfnFunction, cArgs, va); va_end(va); VMR3ReqFree(pReq); return rc; } /** * Convenience wrapper for VMR3ReqCallU. * * This assumes (1) you're calling a function that returns void, and (2) that * you wish to wait for ever for it to return. * * @returns VBox status code of VMR3ReqCallVU. * * @param pUVM Pointer to the user mode VM structure. * @param idDstCpu The destination CPU(s). Either a specific CPU ID or * one of the following special values: * VMCPUID_ANY, VMCPUID_ANY_QUEUE, VMCPUID_ALL or VMCPUID_ALL_REVERSE. * @param pfnFunction Pointer to the function to call. * @param cArgs Number of arguments following in the ellipsis. * @param ... Function arguments. * * @remarks See remarks on VMR3ReqCallVU. */ VMMR3DECL(int) VMR3ReqCallVoidWaitU(PUVM pUVM, VMCPUID idDstCpu, PFNRT pfnFunction, unsigned cArgs, ...) { PVMREQ pReq; va_list va; va_start(va, cArgs); int rc = VMR3ReqCallVU(pUVM, idDstCpu, &pReq, RT_INDEFINITE_WAIT, VMREQFLAGS_VOID, pfnFunction, cArgs, va); va_end(va); VMR3ReqFree(pReq); return rc; } /** * Convenience wrapper for VMR3ReqCallU. * * This assumes (1) you're calling a function that returns void, and (2) that * you do not wish to wait for it to complete. * * @returns VBox status code of VMR3ReqCallVU. * * @param pVM Pointer to the shared VM structure. * @param idDstCpu The destination CPU(s). Either a specific CPU ID or * one of the following special values: * VMCPUID_ANY, VMCPUID_ANY_QUEUE, VMCPUID_ALL or VMCPUID_ALL_REVERSE. * @param pfnFunction Pointer to the function to call. * @param cArgs Number of arguments following in the ellipsis. * @param ... Function arguments. * * @remarks See remarks on VMR3ReqCallVU. */ VMMR3DECL(int) VMR3ReqCallVoidNoWait(PVM pVM, VMCPUID idDstCpu, PFNRT pfnFunction, unsigned cArgs, ...) { PVMREQ pReq; va_list va; va_start(va, cArgs); int rc = VMR3ReqCallVU(pVM->pUVM, idDstCpu, &pReq, RT_INDEFINITE_WAIT, VMREQFLAGS_VOID | VMREQFLAGS_NO_WAIT, pfnFunction, cArgs, va); va_end(va); VMR3ReqFree(pReq); return rc; } /** * Convenience wrapper for VMR3ReqCallU. * * This assumes (1) you're calling a function that returns void, and (2) that * you do not wish to wait for it to complete. * * @returns VBox status code of VMR3ReqCallVU. * * @param pUVM Pointer to the user mode VM structure. * @param idDstCpu The destination CPU(s). Either a specific CPU ID or * one of the following special values: * VMCPUID_ANY, VMCPUID_ANY_QUEUE, VMCPUID_ALL or VMCPUID_ALL_REVERSE. * @param pfnFunction Pointer to the function to call. * @param cArgs Number of arguments following in the ellipsis. * @param ... Function arguments. * * @remarks See remarks on VMR3ReqCallVU. */ VMMR3DECL(int) VMR3ReqCallVoidNoWaitU(PUVM pUVM, VMCPUID idDstCpu, PFNRT pfnFunction, unsigned cArgs, ...) { PVMREQ pReq; va_list va; va_start(va, cArgs); int rc = VMR3ReqCallVU(pUVM, idDstCpu, &pReq, RT_INDEFINITE_WAIT, VMREQFLAGS_VOID | VMREQFLAGS_NO_WAIT, pfnFunction, cArgs, va); va_end(va); VMR3ReqFree(pReq); return rc; } /** * Allocate and queue a call request to a void function. * * If it's desired to poll on the completion of the request set cMillies * to 0 and use VMR3ReqWait() to check for completation. In the other case * use RT_INDEFINITE_WAIT. * The returned request packet must be freed using VMR3ReqFree(). * * @returns VBox status code. * Will not return VERR_INTERRUPTED. * @returns VERR_TIMEOUT if cMillies was reached without the packet being completed. * * @param pUVM Pointer to the user mode VM structure. * @param idDstCpu The destination CPU(s). Either a specific CPU ID or * one of the following special values: * VMCPUID_ANY, VMCPUID_ANY_QUEUE, VMCPUID_ALL or VMCPUID_ALL_REVERSE. * @param ppReq Where to store the pointer to the request. * This will be NULL or a valid request pointer not matter what happends, unless fFlags * contains VMREQFLAGS_NO_WAIT when it will be optional and always NULL. * @param cMillies Number of milliseconds to wait for the request to * be completed. Use RT_INDEFINITE_WAIT to only * wait till it's completed. * @param fFlags A combination of the VMREQFLAGS values. * @param pfnFunction Pointer to the function to call. * @param cArgs Number of arguments following in the ellipsis. * @param ... Function arguments. * * @remarks See remarks on VMR3ReqCallVU. */ VMMR3DECL(int) VMR3ReqCallU(PUVM pUVM, VMCPUID idDstCpu, PVMREQ *ppReq, RTMSINTERVAL cMillies, uint32_t fFlags, PFNRT pfnFunction, unsigned cArgs, ...) { va_list va; va_start(va, cArgs); int rc = VMR3ReqCallVU(pUVM, idDstCpu, ppReq, cMillies, fFlags, pfnFunction, cArgs, va); va_end(va); return rc; } /** * Allocate and queue a call request. * * If it's desired to poll on the completion of the request set cMillies * to 0 and use VMR3ReqWait() to check for completation. In the other case * use RT_INDEFINITE_WAIT. * The returned request packet must be freed using VMR3ReqFree(). * * @returns VBox status code. * Will not return VERR_INTERRUPTED. * @returns VERR_TIMEOUT if cMillies was reached without the packet being completed. * * @param pUVM Pointer to the user mode VM structure. * @param idDstCpu The destination CPU(s). Either a specific CPU ID or * one of the following special values: * VMCPUID_ANY, VMCPUID_ANY_QUEUE, VMCPUID_ALL or VMCPUID_ALL_REVERSE. * @param ppReq Where to store the pointer to the request. * This will be NULL or a valid request pointer not matter what happends, unless fFlags * contains VMREQFLAGS_NO_WAIT when it will be optional and always NULL. * @param cMillies Number of milliseconds to wait for the request to * be completed. Use RT_INDEFINITE_WAIT to only * wait till it's completed. * @param pfnFunction Pointer to the function to call. * @param fFlags A combination of the VMREQFLAGS values. * @param cArgs Number of arguments following in the ellipsis. * Stuff which differs in size from uintptr_t is gonna make trouble, so don't try! * @param Args Argument vector. * * @remarks Caveats: * - Do not pass anything which is larger than an uintptr_t. * - 64-bit integers are larger than uintptr_t on 32-bit hosts. * Pass integers > 32-bit by reference (pointers). * - Don't use NULL since it should be the integer 0 in C++ and may * therefore end up with garbage in the bits 63:32 on 64-bit * hosts because 'int' is 32-bit. * Use (void *)NULL or (uintptr_t)0 instead of NULL. */ VMMR3DECL(int) VMR3ReqCallVU(PUVM pUVM, VMCPUID idDstCpu, PVMREQ *ppReq, RTMSINTERVAL cMillies, uint32_t fFlags, PFNRT pfnFunction, unsigned cArgs, va_list Args) { LogFlow(("VMR3ReqCallV: idDstCpu=%u cMillies=%d fFlags=%#x pfnFunction=%p cArgs=%d\n", idDstCpu, cMillies, fFlags, pfnFunction, cArgs)); /* * Validate input. */ AssertPtrReturn(pfnFunction, VERR_INVALID_POINTER); AssertPtrReturn(pUVM, VERR_INVALID_POINTER); AssertReturn(!(fFlags & ~(VMREQFLAGS_RETURN_MASK | VMREQFLAGS_NO_WAIT | VMREQFLAGS_POKE)), VERR_INVALID_PARAMETER); if (!(fFlags & VMREQFLAGS_NO_WAIT) || ppReq) { AssertPtrReturn(ppReq, VERR_INVALID_POINTER); *ppReq = NULL; } PVMREQ pReq = NULL; AssertMsgReturn(cArgs * sizeof(uintptr_t) <= sizeof(pReq->u.Internal.aArgs), ("cArg=%d\n", cArgs), VERR_TOO_MUCH_DATA); /* * Allocate request */ int rc = VMR3ReqAllocU(pUVM, &pReq, VMREQTYPE_INTERNAL, idDstCpu); if (RT_FAILURE(rc)) return rc; /* * Initialize the request data. */ pReq->fFlags = fFlags; pReq->u.Internal.pfn = pfnFunction; pReq->u.Internal.cArgs = cArgs; for (unsigned iArg = 0; iArg < cArgs; iArg++) pReq->u.Internal.aArgs[iArg] = va_arg(Args, uintptr_t); /* * Queue the request and return. */ rc = VMR3ReqQueue(pReq, cMillies); if ( RT_FAILURE(rc) && rc != VERR_TIMEOUT) { VMR3ReqFree(pReq); pReq = NULL; } if (!(fFlags & VMREQFLAGS_NO_WAIT)) { *ppReq = pReq; LogFlow(("VMR3ReqCallV: returns %Rrc *ppReq=%p\n", rc, pReq)); } else LogFlow(("VMR3ReqCallV: returns %Rrc\n", rc)); Assert(rc != VERR_INTERRUPTED); return rc; } /** * Joins the list pList with whatever is linked up at *pHead. */ static void vmr3ReqJoinFreeSub(volatile PVMREQ *ppHead, PVMREQ pList) { for (unsigned cIterations = 0;; cIterations++) { PVMREQ pHead = (PVMREQ)ASMAtomicXchgPtr((void * volatile *)ppHead, pList); if (!pHead) return; PVMREQ pTail = pHead; while (pTail->pNext) pTail = pTail->pNext; ASMAtomicWritePtr((void * volatile *)&pTail->pNext, pList); ASMCompilerBarrier(); if (ASMAtomicCmpXchgPtr((void * volatile *)ppHead, (void *)pHead, pList)) return; ASMAtomicWritePtr((void * volatile *)&pTail->pNext, NULL); ASMCompilerBarrier(); if (ASMAtomicCmpXchgPtr((void * volatile *)ppHead, (void *)pHead, NULL)) return; pList = pHead; Assert(cIterations != 32); Assert(cIterations != 64); } } /** * Joins the list pList with whatever is linked up at *pHead. */ static void vmr3ReqJoinFree(PVMINTUSERPERVM pVMInt, PVMREQ pList) { /* * Split the list if it's too long. */ unsigned cReqs = 1; PVMREQ pTail = pList; while (pTail->pNext) { if (cReqs++ > 25) { const uint32_t i = pVMInt->iReqFree; vmr3ReqJoinFreeSub(&pVMInt->apReqFree[(i + 2) % RT_ELEMENTS(pVMInt->apReqFree)], pTail->pNext); pTail->pNext = NULL; vmr3ReqJoinFreeSub(&pVMInt->apReqFree[(i + 2 + (i == pVMInt->iReqFree)) % RT_ELEMENTS(pVMInt->apReqFree)], pTail->pNext); return; } pTail = pTail->pNext; } vmr3ReqJoinFreeSub(&pVMInt->apReqFree[(pVMInt->iReqFree + 2) % RT_ELEMENTS(pVMInt->apReqFree)], pList); } /** * Allocates a request packet. * * The caller allocates a request packet, fills in the request data * union and queues the request. * * @returns VBox status code. * * @param pVM VM handle. * @param ppReq Where to store the pointer to the allocated packet. * @param enmType Package type. * @param idDstCpu The destination CPU(s). Either a specific CPU ID or * one of the following special values: * VMCPUID_ANY, VMCPUID_ANY_QUEUE, VMCPUID_ALL or VMCPUID_ALL_REVERSE. */ VMMR3DECL(int) VMR3ReqAlloc(PVM pVM, PVMREQ *ppReq, VMREQTYPE enmType, VMCPUID idDstCpu) { return VMR3ReqAllocU(pVM->pUVM, ppReq, enmType, idDstCpu); } /** * Allocates a request packet. * * The caller allocates a request packet, fills in the request data * union and queues the request. * * @returns VBox status code. * * @param pUVM Pointer to the user mode VM structure. * @param ppReq Where to store the pointer to the allocated packet. * @param enmType Package type. * @param idDstCpu The destination CPU(s). Either a specific CPU ID or * one of the following special values: * VMCPUID_ANY, VMCPUID_ANY_QUEUE, VMCPUID_ALL or VMCPUID_ALL_REVERSE. */ VMMR3DECL(int) VMR3ReqAllocU(PUVM pUVM, PVMREQ *ppReq, VMREQTYPE enmType, VMCPUID idDstCpu) { /* * Validate input. */ AssertMsgReturn(enmType > VMREQTYPE_INVALID && enmType < VMREQTYPE_MAX, ("Invalid package type %d valid range %d-%d inclusivly.\n", enmType, VMREQTYPE_INVALID + 1, VMREQTYPE_MAX - 1), VERR_VM_REQUEST_INVALID_TYPE); AssertPtrReturn(ppReq, VERR_INVALID_POINTER); AssertMsgReturn( idDstCpu == VMCPUID_ANY || idDstCpu == VMCPUID_ANY_QUEUE || idDstCpu < pUVM->cCpus || idDstCpu == VMCPUID_ALL || idDstCpu == VMCPUID_ALL_REVERSE, ("Invalid destination %u (max=%u)\n", idDstCpu, pUVM->cCpus), VERR_INVALID_PARAMETER); /* * Try get a recycled packet. * While this could all be solved with a single list with a lock, it's a sport * of mine to avoid locks. */ int cTries = RT_ELEMENTS(pUVM->vm.s.apReqFree) * 2; while (--cTries >= 0) { PVMREQ volatile *ppHead = &pUVM->vm.s.apReqFree[ASMAtomicIncU32(&pUVM->vm.s.iReqFree) % RT_ELEMENTS(pUVM->vm.s.apReqFree)]; #if 0 /* sad, but this won't work safely because the reading of pReq->pNext. */ PVMREQ pNext = NULL; PVMREQ pReq = *ppHead; if ( pReq && !ASMAtomicCmpXchgPtr((void * volatile *)ppHead, (pNext = pReq->pNext), pReq) && (pReq = *ppHead) && !ASMAtomicCmpXchgPtr((void * volatile *)ppHead, (pNext = pReq->pNext), pReq)) pReq = NULL; if (pReq) { Assert(pReq->pNext == pNext); NOREF(pReq); #else PVMREQ pReq = (PVMREQ)ASMAtomicXchgPtr((void * volatile *)ppHead, NULL); if (pReq) { PVMREQ pNext = pReq->pNext; if ( pNext && !ASMAtomicCmpXchgPtr((void * volatile *)ppHead, pNext, NULL)) { STAM_COUNTER_INC(&pUVM->vm.s.StatReqAllocRaces); vmr3ReqJoinFree(&pUVM->vm.s, pReq->pNext); } #endif ASMAtomicDecU32(&pUVM->vm.s.cReqFree); /* * Make sure the event sem is not signaled. */ if (!pReq->fEventSemClear) { int rc = RTSemEventWait(pReq->EventSem, 0); if (rc != VINF_SUCCESS && rc != VERR_TIMEOUT) { /* * This shall not happen, but if it does we'll just destroy * the semaphore and create a new one. */ AssertMsgFailed(("rc=%Rrc from RTSemEventWait(%#x).\n", rc, pReq->EventSem)); RTSemEventDestroy(pReq->EventSem); rc = RTSemEventCreate(&pReq->EventSem); AssertRC(rc); if (RT_FAILURE(rc)) return rc; #ifdef RT_LOCK_STRICT for (VMCPUID idCpu = 0; idCpu < pUVM->cCpus; idCpu++) RTSemEventAddSignaller(pReq->EventSem, pUVM->aCpus[idCpu].vm.s.ThreadEMT); #endif } pReq->fEventSemClear = true; } else Assert(RTSemEventWait(pReq->EventSem, 0) == VERR_TIMEOUT); /* * Initialize the packet and return it. */ Assert(pReq->enmType == VMREQTYPE_INVALID); Assert(pReq->enmState == VMREQSTATE_FREE); Assert(pReq->pUVM == pUVM); ASMAtomicXchgSize(&pReq->pNext, NULL); pReq->enmState = VMREQSTATE_ALLOCATED; pReq->iStatus = VERR_VM_REQUEST_STATUS_STILL_PENDING; pReq->fFlags = VMREQFLAGS_VBOX_STATUS; pReq->enmType = enmType; pReq->idDstCpu = idDstCpu; *ppReq = pReq; STAM_COUNTER_INC(&pUVM->vm.s.StatReqAllocRecycled); LogFlow(("VMR3ReqAlloc: returns VINF_SUCCESS *ppReq=%p recycled\n", pReq)); return VINF_SUCCESS; } } /* * Ok allocate one. */ PVMREQ pReq = (PVMREQ)MMR3HeapAllocU(pUVM, MM_TAG_VM_REQ, sizeof(*pReq)); if (!pReq) return VERR_NO_MEMORY; /* * Create the semaphore. */ int rc = RTSemEventCreate(&pReq->EventSem); AssertRC(rc); if (RT_FAILURE(rc)) { MMR3HeapFree(pReq); return rc; } #ifdef RT_LOCK_STRICT for (VMCPUID idCpu = 0; idCpu < pUVM->cCpus; idCpu++) RTSemEventAddSignaller(pReq->EventSem, pUVM->aCpus[idCpu].vm.s.ThreadEMT); #endif /* * Initialize the packet and return it. */ pReq->pNext = NULL; pReq->pUVM = pUVM; pReq->enmState = VMREQSTATE_ALLOCATED; pReq->iStatus = VERR_VM_REQUEST_STATUS_STILL_PENDING; pReq->fEventSemClear = true; pReq->fFlags = VMREQFLAGS_VBOX_STATUS; pReq->enmType = enmType; pReq->idDstCpu = idDstCpu; *ppReq = pReq; STAM_COUNTER_INC(&pUVM->vm.s.StatReqAllocNew); LogFlow(("VMR3ReqAlloc: returns VINF_SUCCESS *ppReq=%p new\n", pReq)); return VINF_SUCCESS; } /** * Free a request packet. * * @returns VBox status code. * * @param pReq Package to free. * @remark The request packet must be in allocated or completed state! */ VMMR3DECL(int) VMR3ReqFree(PVMREQ pReq) { /* * Ignore NULL (all free functions should do this imho). */ if (!pReq) return VINF_SUCCESS; /* * Check packet state. */ switch (pReq->enmState) { case VMREQSTATE_ALLOCATED: case VMREQSTATE_COMPLETED: break; default: AssertMsgFailed(("Invalid state %d!\n", pReq->enmState)); return VERR_VM_REQUEST_STATE; } /* * Make it a free packet and put it into one of the free packet lists. */ pReq->enmState = VMREQSTATE_FREE; pReq->iStatus = VERR_VM_REQUEST_STATUS_FREED; pReq->enmType = VMREQTYPE_INVALID; PUVM pUVM = pReq->pUVM; STAM_COUNTER_INC(&pUVM->vm.s.StatReqFree); if (pUVM->vm.s.cReqFree < 128) { ASMAtomicIncU32(&pUVM->vm.s.cReqFree); PVMREQ volatile *ppHead = &pUVM->vm.s.apReqFree[ASMAtomicIncU32(&pUVM->vm.s.iReqFree) % RT_ELEMENTS(pUVM->vm.s.apReqFree)]; PVMREQ pNext; do { pNext = (PVMREQ)ASMAtomicUoReadPtr((void * volatile *)ppHead); ASMAtomicWritePtr((void * volatile *)&pReq->pNext, pNext); ASMCompilerBarrier(); } while (!ASMAtomicCmpXchgPtr((void * volatile *)ppHead, (void *)pReq, (void *)pNext)); } else { STAM_COUNTER_INC(&pReq->pUVM->vm.s.StatReqFreeOverflow); RTSemEventDestroy(pReq->EventSem); MMR3HeapFree(pReq); } return VINF_SUCCESS; } /** * Queue a request. * * The quest must be allocated using VMR3ReqAlloc() and contain * all the required data. * If it's desired to poll on the completion of the request set cMillies * to 0 and use VMR3ReqWait() to check for completation. In the other case * use RT_INDEFINITE_WAIT. * * @returns VBox status code. * Will not return VERR_INTERRUPTED. * @returns VERR_TIMEOUT if cMillies was reached without the packet being completed. * * @param pReq The request to queue. * @param cMillies Number of milliseconds to wait for the request to * be completed. Use RT_INDEFINITE_WAIT to only * wait till it's completed. */ VMMR3DECL(int) VMR3ReqQueue(PVMREQ pReq, RTMSINTERVAL cMillies) { LogFlow(("VMR3ReqQueue: pReq=%p cMillies=%d\n", pReq, cMillies)); /* * Verify the supplied package. */ AssertMsgReturn(pReq->enmState == VMREQSTATE_ALLOCATED, ("%d\n", pReq->enmState), VERR_VM_REQUEST_STATE); AssertMsgReturn( VALID_PTR(pReq->pUVM) && !pReq->pNext && pReq->EventSem != NIL_RTSEMEVENT, ("Invalid request package! Anyone cooking their own packages???\n"), VERR_VM_REQUEST_INVALID_PACKAGE); AssertMsgReturn( pReq->enmType > VMREQTYPE_INVALID && pReq->enmType < VMREQTYPE_MAX, ("Invalid package type %d valid range %d-%d inclusivly. This was verified on alloc too...\n", pReq->enmType, VMREQTYPE_INVALID + 1, VMREQTYPE_MAX - 1), VERR_VM_REQUEST_INVALID_TYPE); Assert(!(pReq->fFlags & ~(VMREQFLAGS_RETURN_MASK | VMREQFLAGS_NO_WAIT | VMREQFLAGS_POKE))); /* * Are we the EMT or not? * Also, store pVM (and fFlags) locally since pReq may be invalid after queuing it. */ int rc = VINF_SUCCESS; PUVM pUVM = ((VMREQ volatile *)pReq)->pUVM; /* volatile paranoia */ PUVMCPU pUVCpu = (PUVMCPU)RTTlsGet(pUVM->vm.s.idxTLS); if (pReq->idDstCpu == VMCPUID_ALL) { /* One-by-one. */ Assert(!(pReq->fFlags & VMREQFLAGS_NO_WAIT)); for (unsigned i = 0; i < pUVM->cCpus; i++) { /* Reinit some members. */ pReq->enmState = VMREQSTATE_ALLOCATED; pReq->idDstCpu = i; rc = VMR3ReqQueue(pReq, cMillies); if (RT_FAILURE(rc)) break; } } else if (pReq->idDstCpu == VMCPUID_ALL_REVERSE) { /* One-by-one. */ Assert(!(pReq->fFlags & VMREQFLAGS_NO_WAIT)); for (int i = pUVM->cCpus-1; i >= 0; i--) { /* Reinit some members. */ pReq->enmState = VMREQSTATE_ALLOCATED; pReq->idDstCpu = i; rc = VMR3ReqQueue(pReq, cMillies); if (RT_FAILURE(rc)) break; } } else if ( pReq->idDstCpu != VMCPUID_ANY /* for a specific VMCPU? */ && pReq->idDstCpu != VMCPUID_ANY_QUEUE && ( !pUVCpu /* and it's not the current thread. */ || pUVCpu->idCpu != pReq->idDstCpu)) { VMCPUID idTarget = pReq->idDstCpu; Assert(idTarget < pUVM->cCpus); PVMCPU pVCpu = &pUVM->pVM->aCpus[idTarget]; unsigned fFlags = ((VMREQ volatile *)pReq)->fFlags; /* volatile paranoia */ /* Fetch the right UVMCPU */ pUVCpu = &pUVM->aCpus[idTarget]; /* * Insert it. */ pReq->enmState = VMREQSTATE_QUEUED; PVMREQ pNext; do { pNext = (PVMREQ)ASMAtomicUoReadPtr((void * volatile *)&pUVCpu->vm.s.pReqs); ASMAtomicWritePtr((void * volatile *)&pReq->pNext, pNext); ASMCompilerBarrier(); } while (!ASMAtomicCmpXchgPtr((void * volatile *)&pUVCpu->vm.s.pReqs, (void *)pReq, (void *)pNext)); /* * Notify EMT. */ if (pUVM->pVM) VMCPU_FF_SET(pVCpu, VMCPU_FF_REQUEST); VMR3NotifyCpuFFU(pUVCpu, fFlags & VMREQFLAGS_POKE ? VMNOTIFYFF_FLAGS_POKE : 0); /* * Wait and return. */ if (!(fFlags & VMREQFLAGS_NO_WAIT)) rc = VMR3ReqWait(pReq, cMillies); LogFlow(("VMR3ReqQueue: returns %Rrc\n", rc)); } else if ( ( pReq->idDstCpu == VMCPUID_ANY && !pUVCpu /* only EMT threads have a valid pointer stored in the TLS slot. */) || pReq->idDstCpu == VMCPUID_ANY_QUEUE) { unsigned fFlags = ((VMREQ volatile *)pReq)->fFlags; /* volatile paranoia */ Assert(pReq->idDstCpu != VMCPUID_ANY_QUEUE || pUVCpu); /* * Insert it. */ pReq->enmState = VMREQSTATE_QUEUED; PVMREQ pNext; do { pNext = (PVMREQ)ASMAtomicUoReadPtr((void * volatile *)&pUVM->vm.s.pReqs); ASMAtomicWritePtr((void * volatile *)&pReq->pNext, pNext); ASMCompilerBarrier(); } while (!ASMAtomicCmpXchgPtr((void * volatile *)&pUVM->vm.s.pReqs, (void *)pReq, (void *)pNext)); /* * Notify EMT. */ if (pUVM->pVM) VM_FF_SET(pUVM->pVM, VM_FF_REQUEST); VMR3NotifyGlobalFFU(pUVM, fFlags & VMREQFLAGS_POKE ? VMNOTIFYFF_FLAGS_POKE : 0); /* * Wait and return. */ if (!(fFlags & VMREQFLAGS_NO_WAIT)) rc = VMR3ReqWait(pReq, cMillies); LogFlow(("VMR3ReqQueue: returns %Rrc\n", rc)); } else { Assert(pUVCpu); /* * The requester was an EMT, just execute it. */ pReq->enmState = VMREQSTATE_QUEUED; rc = vmR3ReqProcessOneU(pUVM, pReq); LogFlow(("VMR3ReqQueue: returns %Rrc (processed)\n", rc)); } return rc; } /** * Wait for a request to be completed. * * @returns VBox status code. * @returns VERR_TIMEOUT if cMillies was reached without the packet being completed. * * @param pReq The request to wait for. * @param cMillies Number of milliseconds to wait. * Use RT_INDEFINITE_WAIT to only wait till it's completed. */ VMMR3DECL(int) VMR3ReqWait(PVMREQ pReq, RTMSINTERVAL cMillies) { LogFlow(("VMR3ReqWait: pReq=%p cMillies=%d\n", pReq, cMillies)); /* * Verify the supplied package. */ AssertMsgReturn( pReq->enmState == VMREQSTATE_QUEUED || pReq->enmState == VMREQSTATE_PROCESSING || pReq->enmState == VMREQSTATE_COMPLETED, ("Invalid state %d\n", pReq->enmState), VERR_VM_REQUEST_STATE); AssertMsgReturn( VALID_PTR(pReq->pUVM) && pReq->EventSem != NIL_RTSEMEVENT, ("Invalid request package! Anyone cooking their own packages???\n"), VERR_VM_REQUEST_INVALID_PACKAGE); AssertMsgReturn( pReq->enmType > VMREQTYPE_INVALID && pReq->enmType < VMREQTYPE_MAX, ("Invalid package type %d valid range %d-%d inclusivly. This was verified on alloc too...\n", pReq->enmType, VMREQTYPE_INVALID + 1, VMREQTYPE_MAX - 1), VERR_VM_REQUEST_INVALID_TYPE); /* * Check for deadlock condition */ PUVM pUVM = pReq->pUVM; NOREF(pUVM); /* * Wait on the package. */ int rc; if (cMillies != RT_INDEFINITE_WAIT) rc = RTSemEventWait(pReq->EventSem, cMillies); else { do { rc = RTSemEventWait(pReq->EventSem, RT_INDEFINITE_WAIT); Assert(rc != VERR_TIMEOUT); } while ( pReq->enmState != VMREQSTATE_COMPLETED && pReq->enmState != VMREQSTATE_INVALID); } if (RT_SUCCESS(rc)) ASMAtomicXchgSize(&pReq->fEventSemClear, true); if (pReq->enmState == VMREQSTATE_COMPLETED) rc = VINF_SUCCESS; LogFlow(("VMR3ReqWait: returns %Rrc\n", rc)); Assert(rc != VERR_INTERRUPTED); return rc; } /** * VMR3ReqProcessU helper that handles cases where there are more than one * pending request. * * @returns The oldest request. * @param pUVM Pointer to the user mode VM structure * @param idDstCpu VMCPUID_ANY or virtual CPU ID. * @param pReqList The list of requests. * @param ppvReqs Pointer to the list head. */ static PVMREQ vmR3ReqProcessUTooManyHelper(PUVM pUVM, VMCPUID idDstCpu, PVMREQ pReqList, void * volatile *ppvReqs) { STAM_COUNTER_INC(&pUVM->vm.s.StatReqMoreThan1); /* Chop off the last one (pReq). */ PVMREQ pPrev; PVMREQ pReqRet = pReqList; do { pPrev = pReqRet; pReqRet = pReqRet->pNext; } while (pReqRet->pNext); ASMAtomicWritePtr((void * volatile *)&pPrev->pNext, NULL); /* Push the others back onto the list (end of it). */ Log2(("VMR3ReqProcess: Pushing back %p %p...\n", pReqList, pReqList->pNext)); if (RT_UNLIKELY(!ASMAtomicCmpXchgPtr(ppvReqs, pReqList, NULL))) { STAM_COUNTER_INC(&pUVM->vm.s.StatReqPushBackRaces); do { ASMNopPause(); PVMREQ pReqList2 = (PVMREQ)ASMAtomicXchgPtr(ppvReqs, NULL); if (pReqList2) { PVMREQ pLast = pReqList2; while (pLast->pNext) pLast = pLast->pNext; ASMAtomicWritePtr((void * volatile *)&pLast->pNext, pReqList); pReqList = pReqList2; } } while (!ASMAtomicCmpXchgPtr(ppvReqs, pReqList, NULL)); } if (RT_LIKELY(pUVM->pVM)) { if (idDstCpu == VMCPUID_ANY) VM_FF_SET(pUVM->pVM, VM_FF_REQUEST); else VMCPU_FF_SET(&pUVM->pVM->aCpus[idDstCpu], VMCPU_FF_REQUEST); } return pReqRet; } /** * Process pending request(s). * * This function is called from a forced action handler in the EMT * or from one of the EMT loops. * * @returns VBox status code. * * @param pUVM Pointer to the user mode VM structure. * @param idDstCpu Pass VMCPUID_ANY to process the common request queue * and the CPU ID for a CPU specific one. In the latter * case the calling thread must be the EMT of that CPU. * * @note SMP safe (multiple EMTs trying to satisfy VM_FF_REQUESTs). * * @remarks This was made reentrant for */ VMMR3DECL(int) VMR3ReqProcessU(PUVM pUVM, VMCPUID idDstCpu) { LogFlow(("VMR3ReqProcessU: (enmVMState=%d) idDstCpu=%d\n", pUVM->pVM ? pUVM->pVM->enmVMState : VMSTATE_CREATING, idDstCpu)); /* * Process loop. * * We do not repeat the outer loop if we've got an informational status code * since that code needs processing by our caller. */ int rc = VINF_SUCCESS; while (rc <= VINF_SUCCESS) { /* * Get the pending requests. * If there are more than one request, unlink the oldest and put the * rest back so that we're reentrant. */ void * volatile *ppvReqs; if (idDstCpu == VMCPUID_ANY) { ppvReqs = (void * volatile *)&pUVM->vm.s.pReqs; if (RT_LIKELY(pUVM->pVM)) VM_FF_CLEAR(pUVM->pVM, VM_FF_REQUEST); } else { Assert(idDstCpu < pUVM->cCpus); Assert(pUVM->aCpus[idDstCpu].vm.s.NativeThreadEMT == RTThreadNativeSelf()); ppvReqs = (void * volatile *)&pUVM->aCpus[idDstCpu].vm.s.pReqs; if (RT_LIKELY(pUVM->pVM)) VMCPU_FF_CLEAR(&pUVM->pVM->aCpus[idDstCpu], VMCPU_FF_REQUEST); } PVMREQ pReq = (PVMREQ)ASMAtomicXchgPtr(ppvReqs, NULL); if (!pReq) break; if (RT_UNLIKELY(pReq->pNext)) pReq = vmR3ReqProcessUTooManyHelper(pUVM, idDstCpu, pReq, ppvReqs); /* * Process the request. * Note! The status code handling here extremely important and yet very * fragile. */ STAM_COUNTER_INC(&pUVM->vm.s.StatReqProcessed); int rc2 = vmR3ReqProcessOneU(pUVM, pReq); if ( rc2 >= VINF_EM_FIRST && rc2 <= VINF_EM_LAST && ( rc == VINF_SUCCESS || rc2 < rc) ) rc = rc2; /** @todo may have to abort processing to propagate EM scheduling status codes * up to the caller... See the ugly hacks after VMMR3EmtRendezvousFF * and VMR3ReqProcessU in EM.cpp. */ } LogFlow(("VMR3ReqProcess: returns %Rrc (enmVMState=%d)\n", rc, pUVM->pVM ? pUVM->pVM->enmVMState : VMSTATE_CREATING)); return rc; } /** * Process one request. * * @returns VBox status code. * * @param pVM VM handle. * @param pReq Request packet to process. */ static int vmR3ReqProcessOneU(PUVM pUVM, PVMREQ pReq) { LogFlow(("vmR3ReqProcessOneU: pReq=%p type=%d fFlags=%#x\n", pReq, pReq->enmType, pReq->fFlags)); /* * Process the request. */ Assert(pReq->enmState == VMREQSTATE_QUEUED); pReq->enmState = VMREQSTATE_PROCESSING; int rcRet = VINF_SUCCESS; /* the return code of this function. */ int rcReq = VERR_NOT_IMPLEMENTED; /* the request status. */ switch (pReq->enmType) { /* * A packed down call frame. */ case VMREQTYPE_INTERNAL: { uintptr_t *pauArgs = &pReq->u.Internal.aArgs[0]; union { PFNRT pfn; DECLCALLBACKMEMBER(int, pfn00)(void); DECLCALLBACKMEMBER(int, pfn01)(uintptr_t); DECLCALLBACKMEMBER(int, pfn02)(uintptr_t, uintptr_t); DECLCALLBACKMEMBER(int, pfn03)(uintptr_t, uintptr_t, uintptr_t); DECLCALLBACKMEMBER(int, pfn04)(uintptr_t, uintptr_t, uintptr_t, uintptr_t); DECLCALLBACKMEMBER(int, pfn05)(uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t); DECLCALLBACKMEMBER(int, pfn06)(uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t); DECLCALLBACKMEMBER(int, pfn07)(uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t); DECLCALLBACKMEMBER(int, pfn08)(uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t); DECLCALLBACKMEMBER(int, pfn09)(uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t); DECLCALLBACKMEMBER(int, pfn10)(uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t); DECLCALLBACKMEMBER(int, pfn11)(uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t); DECLCALLBACKMEMBER(int, pfn12)(uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t); } u; u.pfn = pReq->u.Internal.pfn; #ifdef RT_ARCH_AMD64 switch (pReq->u.Internal.cArgs) { case 0: rcRet = u.pfn00(); break; case 1: rcRet = u.pfn01(pauArgs[0]); break; case 2: rcRet = u.pfn02(pauArgs[0], pauArgs[1]); break; case 3: rcRet = u.pfn03(pauArgs[0], pauArgs[1], pauArgs[2]); break; case 4: rcRet = u.pfn04(pauArgs[0], pauArgs[1], pauArgs[2], pauArgs[3]); break; case 5: rcRet = u.pfn05(pauArgs[0], pauArgs[1], pauArgs[2], pauArgs[3], pauArgs[4]); break; case 6: rcRet = u.pfn06(pauArgs[0], pauArgs[1], pauArgs[2], pauArgs[3], pauArgs[4], pauArgs[5]); break; case 7: rcRet = u.pfn07(pauArgs[0], pauArgs[1], pauArgs[2], pauArgs[3], pauArgs[4], pauArgs[5], pauArgs[6]); break; case 8: rcRet = u.pfn08(pauArgs[0], pauArgs[1], pauArgs[2], pauArgs[3], pauArgs[4], pauArgs[5], pauArgs[6], pauArgs[7]); break; case 9: rcRet = u.pfn09(pauArgs[0], pauArgs[1], pauArgs[2], pauArgs[3], pauArgs[4], pauArgs[5], pauArgs[6], pauArgs[7], pauArgs[8]); break; case 10: rcRet = u.pfn10(pauArgs[0], pauArgs[1], pauArgs[2], pauArgs[3], pauArgs[4], pauArgs[5], pauArgs[6], pauArgs[7], pauArgs[8], pauArgs[9]); break; case 11: rcRet = u.pfn11(pauArgs[0], pauArgs[1], pauArgs[2], pauArgs[3], pauArgs[4], pauArgs[5], pauArgs[6], pauArgs[7], pauArgs[8], pauArgs[9], pauArgs[10]); break; case 12: rcRet = u.pfn12(pauArgs[0], pauArgs[1], pauArgs[2], pauArgs[3], pauArgs[4], pauArgs[5], pauArgs[6], pauArgs[7], pauArgs[8], pauArgs[9], pauArgs[10], pauArgs[11]); break; default: AssertReleaseMsgFailed(("cArgs=%d\n", pReq->u.Internal.cArgs)); rcRet = rcReq = VERR_INTERNAL_ERROR; break; } #else /* x86: */ size_t cbArgs = pReq->u.Internal.cArgs * sizeof(uintptr_t); # ifdef __GNUC__ __asm__ __volatile__("movl %%esp, %%edx\n\t" "subl %2, %%esp\n\t" "andl $0xfffffff0, %%esp\n\t" "shrl $2, %2\n\t" "movl %%esp, %%edi\n\t" "rep movsl\n\t" "movl %%edx, %%edi\n\t" "call *%%eax\n\t" "mov %%edi, %%esp\n\t" : "=a" (rcRet), "=S" (pauArgs), "=c" (cbArgs) : "0" (u.pfn), "1" (pauArgs), "2" (cbArgs) : "edi", "edx"); # else __asm { xor edx, edx /* just mess it up. */ mov eax, u.pfn mov ecx, cbArgs shr ecx, 2 mov esi, pauArgs mov ebx, esp sub esp, cbArgs and esp, 0xfffffff0 mov edi, esp rep movsd call eax mov esp, ebx mov rcRet, eax } # endif #endif /* x86 */ if ((pReq->fFlags & (VMREQFLAGS_RETURN_MASK)) == VMREQFLAGS_VOID) rcRet = VINF_SUCCESS; rcReq = rcRet; break; } default: AssertMsgFailed(("pReq->enmType=%d\n", pReq->enmType)); rcReq = VERR_NOT_IMPLEMENTED; break; } /* * Complete the request. */ pReq->iStatus = rcReq; pReq->enmState = VMREQSTATE_COMPLETED; if (pReq->fFlags & VMREQFLAGS_NO_WAIT) { /* Free the packet, nobody is waiting. */ LogFlow(("vmR3ReqProcessOneU: Completed request %p: rcReq=%Rrc rcRet=%Rrc - freeing it\n", pReq, rcReq, rcRet)); VMR3ReqFree(pReq); } else { /* Notify the waiter and him free up the packet. */ LogFlow(("vmR3ReqProcessOneU: Completed request %p: rcReq=%Rrc rcRet=%Rrc - notifying waiting thread\n", pReq, rcReq, rcRet)); ASMAtomicXchgSize(&pReq->fEventSemClear, false); int rc2 = RTSemEventSignal(pReq->EventSem); if (RT_FAILURE(rc2)) { AssertRC(rc2); rcRet = rc2; } } return rcRet; }