VBoxServicePageSharing.cpp

Last change on this file was 106061, checked in by vboxsync, 2 months ago
Copyright year updates by scm.
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1	/* $Id: VBoxServicePageSharing.cpp 106061 2024-09-16 14:03:52Z vboxsync $ */
2	/** @file
3	* VBoxService - Guest page sharing.
4	*/
5
6	/*
7	* Copyright (C) 2006-2024 Oracle and/or its affiliates.
8	*
9	* This file is part of VirtualBox base platform packages, as
10	* available from https://www.virtualbox.org.
11	*
12	* This program is free software; you can redistribute it and/or
13	* modify it under the terms of the GNU General Public License
14	* as published by the Free Software Foundation, in version 3 of the
15	* License.
16	*
17	* This program is distributed in the hope that it will be useful, but
18	* WITHOUT ANY WARRANTY; without even the implied warranty of
19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20	* General Public License for more details.
21	*
22	* You should have received a copy of the GNU General Public License
23	* along with this program; if not, see <https://www.gnu.org/licenses>.
24	*
25	* SPDX-License-Identifier: GPL-3.0-only
26	*/
27
28
29	/** @page pg_vgsvc_pagesharing VBoxService - Page Sharing
30	*
31	* The Page Sharing subservice is responsible for finding memory mappings
32	* suitable page fusions.
33	*
34	* It is the driving force behind the Page Fusion feature in VirtualBox.
35	* Working with PGM and GMM (ring-0) thru the VMMDev interface. Every so often
36	* it reenumerates the memory mappings (executables and shared libraries) of the
37	* guest OS and reports additions and removals to GMM. For each mapping there
38	* is a filename and version as well as and address range and subsections. GMM
39	* will match the mapping with mapping with the same name and version from other
40	* VMs and see if there are any identical pages between the two.
41	*
42	* To increase the hit rate and reduce the volatility, the service launches a
43	* child process which loads all the Windows system DLLs it can. The child
44	* process is necessary as the DLLs are loaded without running the init code,
45	* and therefore not actually callable for other VBoxService code (may crash).
46	*
47	* This is currently only implemented on Windows. There is no technical reason
48	* for it not to be doable for all the other guests too, it's just a matter of
49	* customer demand and engineering time.
50	*
51	*/
52
53
54	/*********************************************************************************************************************************
55	* Header Files *
56	*********************************************************************************************************************************/
57	#include <iprt/assert.h>
58	#include <iprt/avl.h>
59	#include <iprt/asm.h>
60	#include <iprt/mem.h>
61	#include <iprt/ldr.h>
62	#include <iprt/process.h>
63	#include <iprt/env.h>
64	#include <iprt/stream.h>
65	#include <iprt/file.h>
66	#include <iprt/string.h>
67	#include <iprt/semaphore.h>
68	#include <iprt/string.h>
69	#include <iprt/system.h>
70	#include <iprt/thread.h>
71	#include <iprt/time.h>
72	#include <VBox/err.h>
73	#include <VBox/VMMDev.h>
74	#include <VBox/VBoxGuestLib.h>
75
76	#ifdef RT_OS_WINDOWS
77	#include <iprt/nt/nt-and-windows.h>
78	# include <tlhelp32.h>
79	# include <psapi.h>
80	# include <winternl.h>
81	#endif
82
83	#include "VBoxServiceInternal.h"
84	#include "VBoxServiceUtils.h"
85
86
87	/*********************************************************************************************************************************
88	* Header Files *
89	*********************************************************************************************************************************/
90	typedef struct
91	{
92	AVLPVNODECORE Core;
93	#ifdef RT_OS_WINDOWS
94	HMODULE hModule;
95	char szFileVersion[16];
96	MODULEENTRY32 Info;
97	#endif
98	} VGSVCPGSHKNOWNMOD, *PVGSVCPGSHKNOWNMOD;
99
100
101	/*********************************************************************************************************************************
102	* Global Variables *
103	*********************************************************************************************************************************/
104	/** The semaphore we're blocking on. */
105	static RTSEMEVENTMULTI g_PageSharingEvent = NIL_RTSEMEVENTMULTI;
106
107	static PAVLPVNODECORE g_pKnownModuleTree = NULL;
108	static uint64_t g_idSession = 0;
109
110
111	/*********************************************************************************************************************************
112	* Internal Functions *
113	*********************************************************************************************************************************/
114	static DECLCALLBACK(int) vgsvcPageSharingEmptyTreeCallback(PAVLPVNODECORE pNode, void *pvUser);
115
116
117	#ifdef RT_OS_WINDOWS
118
119	/**
120	* Registers a new module with the VMM
121	* @param pModule Module ptr
122	* @param fValidateMemory Validate/touch memory pages or not
123	* @param pVersionInfo Version info bytes.
124	*/
125	static void vgsvcPageSharingRegisterModuleInner(PVGSVCPGSHKNOWNMOD pModule, bool fValidateMemory, BYTE *pVersionInfo)
126	{
127	VMMDEVSHAREDREGIONDESC aRegions[VMMDEVSHAREDREGIONDESC_MAX];
128	DWORD dwModuleSize = pModule->Info.modBaseSize;
129	BYTE *pBaseAddress = pModule->Info.modBaseAddr;
130
131	/* Fetch default code page. */
132	struct LANGANDCODEPAGE
133	{
134	WORD wLanguage;
135	WORD wCodePage;
136	} *lpTranslate;
137
138	UINT cbTranslate;
139	BOOL fRet = VerQueryValue(pVersionInfo, TEXT("\\VarFileInfo\\Translation"), (LPVOID *)&lpTranslate, &cbTranslate);
140	if ( !fRet
141	\|\| cbTranslate < 4)
142	{
143	VGSvcVerbose(3, "vgsvcPageSharingRegisterModule: VerQueryValue failed with %d (cb=%d)\n", GetLastError(), cbTranslate);
144	return;
145	}
146
147	unsigned i;
148	UINT cbFileVersion;
149	char pszFileVersion = NULL; / Shut up MSC */
150	unsigned cTranslationBlocks = cbTranslate/sizeof(struct LANGANDCODEPAGE);
151
152	pModule->szFileVersion[0] = '\0';
153	for (i = 0; i < cTranslationBlocks; i++)
154	{
155	/* Fetch file version string. */
156	char szFileVersionLocation[256];
157
158	/** @todo r=bird: Mixing ANSI and TCHAR crap again. This code is a mess. We
159	* always use the wide version of the API and convert to UTF-8/whatever. */
160
161	RTStrPrintf(szFileVersionLocation, sizeof(szFileVersionLocation),
162	"\\StringFileInfo\\%04x%04x\\FileVersion", lpTranslate[i].wLanguage, lpTranslate[i].wCodePage);
163	fRet = VerQueryValue(pVersionInfo, szFileVersionLocation, (LPVOID *)&pszFileVersion, &cbFileVersion);
164	if (fRet)
165	{
166	RTStrCopy(pModule->szFileVersion, sizeof(pModule->szFileVersion), pszFileVersion);
167	break;
168	}
169	}
170	if (i == cTranslationBlocks)
171	{
172	VGSvcVerbose(3, "vgsvcPageSharingRegisterModule: no file version found!\n");
173	return;
174	}
175
176	unsigned idxRegion = 0;
177	if (fValidateMemory)
178	{
179	do
180	{
181	MEMORY_BASIC_INFORMATION MemInfo;
182	SIZE_T cbRet = VirtualQuery(pBaseAddress, &MemInfo, sizeof(MemInfo));
183	Assert(cbRet);
184	if (!cbRet)
185	{
186	VGSvcVerbose(3, "vgsvcPageSharingRegisterModule: VirtualQueryEx failed with %d\n", GetLastError());
187	break;
188	}
189
190	if ( MemInfo.State == MEM_COMMIT
191	&& MemInfo.Type == MEM_IMAGE)
192	{
193	switch (MemInfo.Protect)
194	{
195	case PAGE_EXECUTE:
196	case PAGE_EXECUTE_READ:
197	case PAGE_READONLY:
198	{
199	char pRegion = (char )MemInfo.BaseAddress;
200
201	/* Skip the first region as it only contains the image file header. */
202	if (pRegion != (char *)pModule->Info.modBaseAddr)
203	{
204	/* Touch all pages. */
205	while ((uintptr_t)pRegion < (uintptr_t)MemInfo.BaseAddress + MemInfo.RegionSize)
206	{
207	/* Try to trick the optimizer to leave the page touching code in place. */
208	ASMProbeReadByte(pRegion);
209	pRegion += PAGE_SIZE;
210	}
211	}
212	#ifdef RT_ARCH_X86
213	aRegions[idxRegion].GCRegionAddr = (RTGCPTR32)MemInfo.BaseAddress;
214	#else
215	aRegions[idxRegion].GCRegionAddr = (RTGCPTR64)MemInfo.BaseAddress;
216	#endif
217	aRegions[idxRegion].cbRegion = MemInfo.RegionSize;
218	idxRegion++;
219
220	break;
221	}
222
223	default:
224	break; /* ignore */
225	}
226	}
227
228	pBaseAddress = (BYTE *)MemInfo.BaseAddress + MemInfo.RegionSize;
229	if (dwModuleSize > MemInfo.RegionSize)
230	dwModuleSize -= MemInfo.RegionSize;
231	else
232	{
233	dwModuleSize = 0;
234	break;
235	}
236
237	if (idxRegion >= RT_ELEMENTS(aRegions))
238	break; /* out of room */
239	} while (dwModuleSize);
240	}
241	else
242	{
243	/* We can't probe kernel memory ranges, so pretend it's one big region. */
244	#ifdef RT_ARCH_X86
245	aRegions[idxRegion].GCRegionAddr = (RTGCPTR32)pBaseAddress;
246	#else
247	aRegions[idxRegion].GCRegionAddr = (RTGCPTR64)pBaseAddress;
248	#endif
249	aRegions[idxRegion].cbRegion = dwModuleSize;
250	idxRegion++;
251	}
252	VGSvcVerbose(3, "vgsvcPageSharingRegisterModule: VbglR3RegisterSharedModule %s %s base=%p size=%x cregions=%d\n",
253	pModule->Info.szModule, pModule->szFileVersion, pModule->Info.modBaseAddr, pModule->Info.modBaseSize, idxRegion);
254	int rc = VbglR3RegisterSharedModule(pModule->Info.szModule, pModule->szFileVersion, (uintptr_t)pModule->Info.modBaseAddr,
255	pModule->Info.modBaseSize, idxRegion, aRegions);
256	if (RT_FAILURE(rc))
257	VGSvcVerbose(3, "vgsvcPageSharingRegisterModule: VbglR3RegisterSharedModule failed with %Rrc\n", rc);
258	}
259
260
261	/**
262	* Registers a new module with the VMM
263	* @param pModule Module ptr
264	* @param fValidateMemory Validate/touch memory pages or not
265	*/
266	static void vgsvcPageSharingRegisterModule(PVGSVCPGSHKNOWNMOD pModule, bool fValidateMemory)
267	{
268	VGSvcVerbose(3, "vgsvcPageSharingRegisterModule\n");
269
270	DWORD dwDummy;
271	DWORD cbVersion = GetFileVersionInfoSize(pModule->Info.szExePath, &dwDummy);
272	if (cbVersion)
273	{
274	BYTE pVersionInfo = (BYTE )RTMemTmpAllocZ(cbVersion);
275	if (pVersionInfo)
276	{
277	if (GetFileVersionInfo(pModule->Info.szExePath, 0, cbVersion, pVersionInfo))
278	vgsvcPageSharingRegisterModuleInner(pModule, fValidateMemory, pVersionInfo);
279	else
280	VGSvcVerbose(3, "vgsvcPageSharingRegisterModule: GetFileVersionInfo failed with %d\n", GetLastError());
281	RTMemTmpFree(pVersionInfo);
282	}
283	}
284	else
285	VGSvcVerbose(3, "vgsvcPageSharingRegisterModule: GetFileVersionInfoSize failed with %d\n", GetLastError());
286	}
287
288
289	/**
290	* Inspect all loaded modules for the specified process
291	*
292	* @param dwProcessId Process id
293	* @param ppNewTree The module tree we're assembling from modules found
294	* in this process. Modules found are moved from
295	* g_pKnownModuleTree or created new.
296	*/
297	static void vgsvcPageSharingInspectModules(DWORD dwProcessId, PAVLPVNODECORE *ppNewTree)
298	{
299	/* Get a list of all the modules in this process. */
300	HANDLE hProcess = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE /* no child process handle inheritance */, dwProcessId);
301	if (hProcess == NULL)
302	{
303	VGSvcVerbose(3, "vgsvcPageSharingInspectModules: OpenProcess %x failed with %d\n", dwProcessId, GetLastError());
304	return;
305	}
306
307	HANDLE hSnapshot = g_pfnCreateToolhelp32Snapshot(TH32CS_SNAPMODULE, dwProcessId);
308	if (hSnapshot == INVALID_HANDLE_VALUE)
309	{
310	VGSvcVerbose(3, "vgsvcPageSharingInspectModules: CreateToolhelp32Snapshot failed with %d\n", GetLastError());
311	CloseHandle(hProcess);
312	return;
313	}
314
315	VGSvcVerbose(3, "vgsvcPageSharingInspectModules\n");
316
317	MODULEENTRY32 ModuleInfo;
318	BOOL bRet;
319
320	ModuleInfo.dwSize = sizeof(ModuleInfo);
321	bRet = g_pfnModule32First(hSnapshot, &ModuleInfo);
322	do
323	{
324	/** @todo when changing this make sure VBoxService.exe is excluded! */
325	char *pszDot = strrchr(ModuleInfo.szModule, '.');
326	if ( pszDot
327	&& (pszDot[1] == 'e' \|\| pszDot[1] == 'E'))
328	continue; /* ignore executables for now. */
329
330	/* Found it before? */
331	PAVLPVNODECORE pRec = RTAvlPVGet(ppNewTree, ModuleInfo.modBaseAddr);
332	if (!pRec)
333	{
334	pRec = RTAvlPVRemove(&g_pKnownModuleTree, ModuleInfo.modBaseAddr);
335	if (!pRec)
336	{
337	/* New module; register it. */
338	PVGSVCPGSHKNOWNMOD pModule = (PVGSVCPGSHKNOWNMOD)RTMemAllocZ(sizeof(*pModule));
339	Assert(pModule);
340	if (!pModule)
341	break;
342
343	pModule->Info = ModuleInfo;
344	pModule->Core.Key = ModuleInfo.modBaseAddr;
345	pModule->hModule = LoadLibraryEx(ModuleInfo.szExePath, 0, DONT_RESOLVE_DLL_REFERENCES);
346	if (pModule->hModule)
347	vgsvcPageSharingRegisterModule(pModule, true /* validate pages */);
348
349	VGSvcVerbose(3, "\n\n MODULE NAME: %s", ModuleInfo.szModule );
350	VGSvcVerbose(3, "\n executable = %s", ModuleInfo.szExePath );
351	VGSvcVerbose(3, "\n process ID = 0x%08X", ModuleInfo.th32ProcessID );
352	VGSvcVerbose(3, "\n base address = %#010p", (uintptr_t) ModuleInfo.modBaseAddr );
353	VGSvcVerbose(3, "\n base size = %d", ModuleInfo.modBaseSize );
354
355	pRec = &pModule->Core;
356	}
357	bool ret = RTAvlPVInsert(ppNewTree, pRec);
358	Assert(ret); NOREF(ret);
359	}
360	} while (g_pfnModule32Next(hSnapshot, &ModuleInfo));
361
362	CloseHandle(hSnapshot);
363	CloseHandle(hProcess);
364	}
365
366
367	/**
368	* Inspect all running processes for executables and dlls that might be worth sharing
369	* with other VMs.
370	*
371	*/
372	static void vgsvcPageSharingInspectGuest(void)
373	{
374	VGSvcVerbose(3, "vgsvcPageSharingInspectGuest\n");
375	PAVLPVNODECORE pNewTree = NULL;
376
377	/*
378	* Check loaded modules for all running processes.
379	*/
380	if ( g_pfnProcess32First
381	&& g_pfnProcess32Next
382	&& g_pfnModule32First
383	&& g_pfnModule32Next
384	&& g_pfnCreateToolhelp32Snapshot)
385	{
386	HANDLE hSnapshot = g_pfnCreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
387	if (hSnapshot == INVALID_HANDLE_VALUE)
388	{
389	VGSvcVerbose(3, "vgsvcPageSharingInspectGuest: CreateToolhelp32Snapshot failed with %d\n", GetLastError());
390	return;
391	}
392
393	DWORD const dwProcessId = GetCurrentProcessId();
394
395	PROCESSENTRY32 ProcessInfo;
396	ProcessInfo.dwSize = sizeof(ProcessInfo);
397	g_pfnProcess32First(hSnapshot, &ProcessInfo);
398
399	do
400	{
401	/* Skip our own process. */
402	if (ProcessInfo.th32ProcessID != dwProcessId)
403	vgsvcPageSharingInspectModules(ProcessInfo.th32ProcessID, &pNewTree);
404	}
405	while (g_pfnProcess32Next(hSnapshot, &ProcessInfo));
406
407	CloseHandle(hSnapshot);
408	}
409
410	/*
411	* Check all loaded kernel modules.
412	*/
413	if (g_pfnZwQuerySystemInformation)
414	{
415	ULONG cbBuffer = 0;
416	PVOID pBuffer = NULL;
417	PRTL_PROCESS_MODULES pSystemModules;
418
419	NTSTATUS ret = g_pfnZwQuerySystemInformation(SystemModuleInformation, (PVOID)&cbBuffer, 0, &cbBuffer);
420	if (!cbBuffer)
421	{
422	VGSvcVerbose(1, "ZwQuerySystemInformation returned length 0\n");
423	goto skipkernelmodules;
424	}
425
426	pBuffer = RTMemAllocZ(cbBuffer);
427	if (!pBuffer)
428	goto skipkernelmodules;
429
430	ret = g_pfnZwQuerySystemInformation(SystemModuleInformation, pBuffer, cbBuffer, &cbBuffer);
431	if (ret != STATUS_SUCCESS)
432	{
433	VGSvcVerbose(1, "ZwQuerySystemInformation returned %x (1)\n", ret);
434	goto skipkernelmodules;
435	}
436
437	pSystemModules = (PRTL_PROCESS_MODULES)pBuffer;
438	for (unsigned i = 0; i < pSystemModules->NumberOfModules; i++)
439	{
440	VGSvcVerbose(4, "\n\n KERNEL MODULE NAME: %s", pSystemModules->Modules[i].FullPathName[pSystemModules->Modules[i].OffsetToFileName] );
441	VGSvcVerbose(4, "\n executable = %s", pSystemModules->Modules[i].FullPathName );
442	VGSvcVerbose(4, "\n flags = 0x%08X\n", pSystemModules->Modules[i].Flags);
443
444	/* User-mode modules seem to have no flags set; skip them as we detected them above. */
445	if (pSystemModules->Modules[i].Flags == 0)
446	continue;
447
448	/* Found it before? */
449	PAVLPVNODECORE pRec = RTAvlPVGet(&pNewTree, pSystemModules->Modules[i].ImageBase);
450	if (!pRec)
451	{
452	pRec = RTAvlPVRemove(&g_pKnownModuleTree, pSystemModules->Modules[i].ImageBase);
453	if (!pRec)
454	{
455	/* New module; register it. */
456	char szFullFilePath[512];
457	PVGSVCPGSHKNOWNMOD pModule = (PVGSVCPGSHKNOWNMOD)RTMemAllocZ(sizeof(*pModule));
458	Assert(pModule);
459	if (!pModule)
460	break;
461
462	/** @todo FullPathName not an UTF-8 string is! An ANSI string it is
463	* according to the SYSTEM locale. Best use RtlAnsiStringToUnicodeString to
464	* convert to UTF-16. */
465	strcpy(pModule->Info.szModule,
466	(const char *)&pSystemModules->Modules[i].FullPathName[pSystemModules->Modules[i].OffsetToFileName]);
467	GetSystemDirectoryA(szFullFilePath, sizeof(szFullFilePath));
468
469	/* skip \Systemroot\system32 */
470	char lpPath = strchr((char )&pSystemModules->Modules[i].FullPathName[1], '\\');
471	if (!lpPath)
472	{
473	/* Seen just file names in XP; try to locate the file in the system32 and system32\drivers directories. */
474	RTStrCat(szFullFilePath, sizeof(szFullFilePath), "\\");
475	RTStrCat(szFullFilePath, sizeof(szFullFilePath), (const char *)pSystemModules->Modules[i].FullPathName);
476	VGSvcVerbose(3, "Unexpected kernel module name try %s\n", szFullFilePath);
477	if (RTFileExists(szFullFilePath) == false)
478	{
479	GetSystemDirectoryA(szFullFilePath, sizeof(szFullFilePath));
480	RTStrCat(szFullFilePath, sizeof(szFullFilePath), "\\drivers\\");
481	RTStrCat(szFullFilePath, sizeof(szFullFilePath), (const char *)pSystemModules->Modules[i].FullPathName);
482	VGSvcVerbose(3, "Unexpected kernel module name try %s\n", szFullFilePath);
483	if (RTFileExists(szFullFilePath) == false)
484	{
485	VGSvcVerbose(1, "Unexpected kernel module name %s\n", pSystemModules->Modules[i].FullPathName);
486	RTMemFree(pModule);
487	continue;
488	}
489	}
490	}
491	else
492	{
493	lpPath = strchr(lpPath + 1, '\\');
494	if (!lpPath)
495	{
496	VGSvcVerbose(1, "Unexpected kernel module name %s (2)\n", pSystemModules->Modules[i].FullPathName);
497	RTMemFree(pModule);
498	continue;
499	}
500
501	RTStrCat(szFullFilePath, sizeof(szFullFilePath), lpPath);
502	}
503
504	strcpy(pModule->Info.szExePath, szFullFilePath);
505	pModule->Info.modBaseAddr = (BYTE *)pSystemModules->Modules[i].ImageBase;
506	pModule->Info.modBaseSize = pSystemModules->Modules[i].ImageSize;
507
508	pModule->Core.Key = pSystemModules->Modules[i].ImageBase;
509	vgsvcPageSharingRegisterModule(pModule, false /* don't check memory pages */);
510
511	VGSvcVerbose(3, "\n\n KERNEL MODULE NAME: %s", pModule->Info.szModule );
512	VGSvcVerbose(3, "\n executable = %s", pModule->Info.szExePath );
513	VGSvcVerbose(3, "\n base address = %#010p", (uintptr_t)pModule->Info.modBaseAddr );
514	VGSvcVerbose(3, "\n flags = 0x%08X", pSystemModules->Modules[i].Flags);
515	VGSvcVerbose(3, "\n base size = %d", pModule->Info.modBaseSize );
516
517	pRec = &pModule->Core;
518	}
519	bool fRet = RTAvlPVInsert(&pNewTree, pRec);
520	Assert(fRet); NOREF(fRet);
521	}
522	}
523	skipkernelmodules:
524	if (pBuffer)
525	RTMemFree(pBuffer);
526	}
527
528	/* Delete leftover modules in the old tree. */
529	RTAvlPVDestroy(&g_pKnownModuleTree, vgsvcPageSharingEmptyTreeCallback, NULL);
530
531	/* Check all registered modules. */
532	VbglR3CheckSharedModules();
533
534	/* Activate new module tree. */
535	g_pKnownModuleTree = pNewTree;
536	}
537
538
539	/**
540	* RTAvlPVDestroy callback.
541	*/
542	static DECLCALLBACK(int) vgsvcPageSharingEmptyTreeCallback(PAVLPVNODECORE pNode, void *pvUser)
543	{
544	PVGSVCPGSHKNOWNMOD pModule = (PVGSVCPGSHKNOWNMOD)pNode;
545	bool pfUnregister = (bool )pvUser;
546
547	VGSvcVerbose(3, "vgsvcPageSharingEmptyTreeCallback %s %s\n", pModule->Info.szModule, pModule->szFileVersion);
548
549	/* Dereference module in the hypervisor. */
550	if ( !pfUnregister
551	\|\| *pfUnregister)
552	{
553	int rc = VbglR3UnregisterSharedModule(pModule->Info.szModule, pModule->szFileVersion,
554	(uintptr_t)pModule->Info.modBaseAddr, pModule->Info.modBaseSize);
555	AssertRC(rc);
556	}
557
558	if (pModule->hModule)
559	FreeLibrary(pModule->hModule);
560	RTMemFree(pNode);
561	return 0;
562	}
563
564
565	#else /* !RT_OS_WINDOWS */
566
567	static void vgsvcPageSharingInspectGuest(void)
568	{
569	/** @todo other platforms */
570	}
571
572	#endif /* !RT_OS_WINDOWS */
573
574	/** @interface_method_impl{VBOXSERVICE,pfnInit} */
575	static DECLCALLBACK(int) vgsvcPageSharingInit(void)
576	{
577	VGSvcVerbose(3, "vgsvcPageSharingInit\n");
578
579	int rc = RTSemEventMultiCreate(&g_PageSharingEvent);
580	AssertRCReturn(rc, rc);
581
582	#ifdef RT_OS_WINDOWS
583	rc = VbglR3GetSessionId(&g_idSession);
584	if (RT_FAILURE(rc))
585	{
586	if (rc == VERR_IO_GEN_FAILURE)
587	VGSvcVerbose(0, "PageSharing: Page sharing support is not available by the host\n");
588	else
589	VGSvcError("vgsvcPageSharingInit: Failed with rc=%Rrc\n", rc);
590
591	rc = VERR_SERVICE_DISABLED;
592
593	RTSemEventMultiDestroy(g_PageSharingEvent);
594	g_PageSharingEvent = NIL_RTSEMEVENTMULTI;
595
596	}
597	#endif
598
599	return rc;
600	}
601
602
603	/**
604	* @interface_method_impl{VBOXSERVICE,pfnWorker}
605	*/
606	static DECLCALLBACK(int) vgsvcPageSharingWorker(bool volatile *pfShutdown)
607	{
608	/*
609	* Tell the control thread that it can continue
610	* spawning services.
611	*/
612	RTThreadUserSignal(RTThreadSelf());
613
614	/*
615	* Now enter the loop retrieving runtime data continuously.
616	*/
617	for (;;)
618	{
619	bool fEnabled = VbglR3PageSharingIsEnabled();
620	VGSvcVerbose(3, "vgsvcPageSharingWorker: enabled=%d\n", fEnabled);
621
622	if (fEnabled)
623	vgsvcPageSharingInspectGuest();
624
625	/*
626	* Block for a minute.
627	*
628	* The event semaphore takes care of ignoring interruptions and it
629	* allows us to implement service wakeup later.
630	*/
631	if (*pfShutdown)
632	break;
633	int rc = RTSemEventMultiWait(g_PageSharingEvent, 60000);
634	if (*pfShutdown)
635	break;
636	if (rc != VERR_TIMEOUT && RT_FAILURE(rc))
637	{
638	VGSvcError("vgsvcPageSharingWorker: RTSemEventMultiWait failed; rc=%Rrc\n", rc);
639	break;
640	}
641	#ifdef RT_OS_WINDOWS
642	uint64_t idNewSession = g_idSession;
643	rc = VbglR3GetSessionId(&idNewSession);
644	AssertRC(rc);
645
646	if (idNewSession != g_idSession)
647	{
648	bool fUnregister = false;
649
650	VGSvcVerbose(3, "vgsvcPageSharingWorker: VM was restored!!\n");
651	/* The VM was restored, so reregister all modules the next time. */
652	RTAvlPVDestroy(&g_pKnownModuleTree, vgsvcPageSharingEmptyTreeCallback, &fUnregister);
653	g_pKnownModuleTree = NULL;
654
655	g_idSession = idNewSession;
656	}
657	#endif
658	}
659
660	RTSemEventMultiDestroy(g_PageSharingEvent);
661	g_PageSharingEvent = NIL_RTSEMEVENTMULTI;
662
663	VGSvcVerbose(3, "vgsvcPageSharingWorker: finished thread\n");
664	return 0;
665	}
666
667	#ifdef RT_OS_WINDOWS
668
669	/**
670	* This gets control when VBoxService is launched with "pagefusion" by
671	* vgsvcPageSharingWorkerProcess().
672	*
673	* @returns RTEXITCODE_SUCCESS.
674	*
675	* @remarks It won't normally return since the parent drops the shutdown hint
676	* via RTProcTerminate().
677	*/
678	RTEXITCODE VGSvcPageSharingWorkerChild(void)
679	{
680	VGSvcVerbose(3, "vgsvcPageSharingInitFork\n");
681
682	bool fShutdown = false;
683	vgsvcPageSharingInit();
684	vgsvcPageSharingWorker(&fShutdown);
685
686	return RTEXITCODE_SUCCESS;
687	}
688
689
690	/**
691	* @interface_method_impl{VBOXSERVICE,pfnWorker}
692	*/
693	static DECLCALLBACK(int) vgsvcPageSharingWorkerProcess(bool volatile *pfShutdown)
694	{
695	RTPROCESS hProcess = NIL_RTPROCESS;
696	int rc;
697
698	/*
699	* Tell the control thread that it can continue
700	* spawning services.
701	*/
702	RTThreadUserSignal(RTThreadSelf());
703
704	/*
705	* Now enter the loop retrieving runtime data continuously.
706	*/
707	for (;;)
708	{
709	bool fEnabled = VbglR3PageSharingIsEnabled();
710	VGSvcVerbose(3, "vgsvcPageSharingWorkerProcess: enabled=%d\n", fEnabled);
711
712	/*
713	* Start a 2nd VBoxService process to deal with page fusion as we do
714	* not wish to dummy load dlls into this process. (First load with
715	* DONT_RESOLVE_DLL_REFERENCES, 2nd normal -> dll init routines not called!)
716	*/
717	if ( fEnabled
718	&& hProcess == NIL_RTPROCESS)
719	{
720	char szExeName[256];
721	char *pszExeName = RTProcGetExecutablePath(szExeName, sizeof(szExeName));
722	if (pszExeName)
723	{
724	char const *papszArgs[3];
725	papszArgs[0] = pszExeName;
726	papszArgs[1] = "pagefusion";
727	papszArgs[2] = NULL;
728	rc = RTProcCreate(pszExeName, papszArgs, RTENV_DEFAULT, 0 /* normal child */, &hProcess);
729	if (RT_FAILURE(rc))
730	VGSvcError("vgsvcPageSharingWorkerProcess: RTProcCreate %s failed; rc=%Rrc\n", pszExeName, rc);
731	}
732	}
733
734	/*
735	* Block for a minute.
736	*
737	* The event semaphore takes care of ignoring interruptions and it
738	* allows us to implement service wakeup later.
739	*/
740	if (*pfShutdown)
741	break;
742	rc = RTSemEventMultiWait(g_PageSharingEvent, 60000);
743	if (*pfShutdown)
744	break;
745	if (rc != VERR_TIMEOUT && RT_FAILURE(rc))
746	{
747	VGSvcError("vgsvcPageSharingWorkerProcess: RTSemEventMultiWait failed; rc=%Rrc\n", rc);
748	break;
749	}
750	}
751
752	if (hProcess != NIL_RTPROCESS)
753	RTProcTerminate(hProcess);
754
755	VGSvcVerbose(3, "vgsvcPageSharingWorkerProcess: finished thread\n");
756	return 0;
757	}
758
759	#endif /* RT_OS_WINDOWS */
760
761	/**
762	* @interface_method_impl{VBOXSERVICE,pfnStop}
763	*/
764	static DECLCALLBACK(void) vgsvcPageSharingStop(void)
765	{
766	RTSemEventMultiSignal(g_PageSharingEvent);
767	}
768
769
770	/**
771	* @interface_method_impl{VBOXSERVICE,pfnTerm}
772	*/
773	static DECLCALLBACK(void) vgsvcPageSharingTerm(void)
774	{
775	if (g_PageSharingEvent != NIL_RTSEMEVENTMULTI)
776	{
777	RTSemEventMultiDestroy(g_PageSharingEvent);
778	g_PageSharingEvent = NIL_RTSEMEVENTMULTI;
779	}
780	}
781
782
783	/**
784	* The 'pagesharing' service description.
785	*/
786	VBOXSERVICE g_PageSharing =
787	{
788	/* pszName. */
789	"pagesharing",
790	/* pszDescription. */
791	"Page Sharing",
792	/* pszUsage. */
793	NULL,
794	/* pszOptions. */
795	NULL,
796	/* methods */
797	VGSvcDefaultPreInit,
798	VGSvcDefaultOption,
799	vgsvcPageSharingInit,
800	#ifdef RT_OS_WINDOWS
801	vgsvcPageSharingWorkerProcess,
802	#else
803	vgsvcPageSharingWorker,
804	#endif
805	vgsvcPageSharingStop,
806	vgsvcPageSharingTerm
807	};
808

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source: vbox/trunk/src/VBox/Additions/common/VBoxService/VBoxServicePageSharing.cpp

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