VirtualBox

source: vbox/trunk/src/VBox/VMM/VMMR0/PGMR0SharedPage.cpp@ 43045

Last change on this file since 43045 was 43045, checked in by vboxsync, 12 years ago

PGM: Employ the 4 unused PGMPHYSPAGE bits for checksumming shared pages in strict builds.

  • Property svn:eol-style set to native
  • Property svn:keywords set to Id Revision
File size: 7.0 KB
Line 
1/* $Id: PGMR0SharedPage.cpp 43045 2012-08-28 14:21:43Z vboxsync $ */
2/** @file
3 * PGM - Page Manager and Monitor, Page Sharing, Ring-0.
4 */
5
6/*
7 * Copyright (C) 2010-2012 Oracle Corporation
8 *
9 * This file is part of VirtualBox Open Source Edition (OSE), as
10 * available from http://www.virtualbox.org. This file is free software;
11 * you can redistribute it and/or modify it under the terms of the GNU
12 * General Public License (GPL) as published by the Free Software
13 * Foundation, in version 2 as it comes in the "COPYING" file of the
14 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16 */
17
18/*******************************************************************************
19* Header Files *
20*******************************************************************************/
21#define LOG_GROUP LOG_GROUP_PGM_SHARED
22#include <VBox/vmm/pgm.h>
23#include <VBox/vmm/gmm.h>
24#include "PGMInternal.h"
25#include <VBox/vmm/vm.h>
26#include "PGMInline.h"
27#include <VBox/log.h>
28#include <VBox/err.h>
29#include <iprt/assert.h>
30#include <iprt/mem.h>
31
32
33#ifdef VBOX_WITH_PAGE_SHARING
34/**
35 * Check a registered module for shared page changes.
36 *
37 * The PGM lock shall be taken prior to calling this method.
38 *
39 * @returns The following VBox status codes.
40 *
41 * @param pVM Pointer to the VM.
42 * @param pGVM Pointer to the GVM instance data.
43 * @param idCpu The ID of the calling virtual CPU.
44 * @param pModule Global module description.
45 * @param paRegionsGCPtrs Array parallel to pModules->aRegions with the
46 * addresses of the regions in the calling
47 * process.
48 */
49VMMR0DECL(int) PGMR0SharedModuleCheck(PVM pVM, PGVM pGVM, VMCPUID idCpu, PGMMSHAREDMODULE pModule, PCRTGCPTR64 paRegionsGCPtrs)
50{
51 PVMCPU pVCpu = &pVM->aCpus[idCpu];
52 int rc = VINF_SUCCESS;
53 bool fFlushTLBs = false;
54 bool fFlushRemTLBs = false;
55 GMMSHAREDPAGEDESC PageDesc;
56
57 Log(("PGMR0SharedModuleCheck: check %s %s base=%RGv size=%x\n", pModule->szName, pModule->szVersion, pModule->Core.Key, pModule->cbModule));
58
59 PGM_LOCK_ASSERT_OWNER(pVM); /* This cannot fail as we grab the lock in pgmR3SharedModuleRegRendezvous before calling into ring-0. */
60
61 /*
62 * Check every region of the shared module.
63 */
64 for (uint32_t idxRegion = 0; idxRegion < pModule->cRegions; idxRegion++)
65 {
66 RTGCPTR GCPtrPage = paRegionsGCPtrs[idxRegion] & ~(RTGCPTR)PAGE_OFFSET_MASK;
67 uint32_t cbLeft = pModule->aRegions[idxRegion].cb; Assert(!(cbLeft & PAGE_OFFSET_MASK));
68 uint32_t idxPage = 0;
69
70 while (cbLeft)
71 {
72 /** @todo inefficient to fetch each guest page like this... */
73 RTGCPHYS GCPhys;
74 uint64_t fFlags;
75 rc = PGMGstGetPage(pVCpu, GCPtrPage, &fFlags, &GCPhys);
76 if ( rc == VINF_SUCCESS
77 && !(fFlags & X86_PTE_RW)) /* important as we make assumptions about this below! */
78 {
79 PPGMPAGE pPage = pgmPhysGetPage(pVM, GCPhys);
80 Assert(!pPage || !PGM_PAGE_IS_BALLOONED(pPage));
81 if ( pPage
82 && PGM_PAGE_GET_STATE(pPage) == PGM_PAGE_STATE_ALLOCATED
83 && PGM_PAGE_GET_READ_LOCKS(pPage) == 0
84 && PGM_PAGE_GET_WRITE_LOCKS(pPage) == 0 )
85 {
86 PageDesc.idPage = PGM_PAGE_GET_PAGEID(pPage);
87 PageDesc.HCPhys = PGM_PAGE_GET_HCPHYS(pPage);
88 PageDesc.GCPhys = GCPhys;
89
90 rc = GMMR0SharedModuleCheckPage(pGVM, pModule, idxRegion, idxPage, &PageDesc);
91 if (RT_FAILURE(rc))
92 break;
93
94 /*
95 * Any change for this page?
96 */
97 if (PageDesc.idPage != NIL_GMM_PAGEID)
98 {
99 Assert(PGM_PAGE_GET_STATE(pPage) == PGM_PAGE_STATE_ALLOCATED);
100
101 Log(("PGMR0SharedModuleCheck: shared page gst virt=%RGv phys=%RGp host %RHp->%RHp\n",
102 GCPtrPage, PageDesc.GCPhys, PGM_PAGE_GET_HCPHYS(pPage), PageDesc.HCPhys));
103
104 /* Page was either replaced by an existing shared
105 version of it or converted into a read-only shared
106 page, so, clear all references. */
107 bool fFlush = false;
108 rc = pgmPoolTrackUpdateGCPhys(pVM, PageDesc.GCPhys, pPage, true /* clear the entries */, &fFlush);
109 Assert( rc == VINF_SUCCESS
110 || ( VMCPU_FF_ISSET(pVCpu, VMCPU_FF_PGM_SYNC_CR3)
111 && (pVCpu->pgm.s.fSyncFlags & PGM_SYNC_CLEAR_PGM_POOL)));
112 if (rc == VINF_SUCCESS)
113 fFlushTLBs |= fFlush;
114 fFlushRemTLBs = true;
115
116 if (PageDesc.HCPhys != PGM_PAGE_GET_HCPHYS(pPage))
117 {
118 /* Update the physical address and page id now. */
119 PGM_PAGE_SET_HCPHYS(pVM, pPage, PageDesc.HCPhys);
120 PGM_PAGE_SET_PAGEID(pVM, pPage, PageDesc.idPage);
121
122 /* Invalidate page map TLB entry for this page too. */
123 pgmPhysInvalidatePageMapTLBEntry(pVM, PageDesc.GCPhys);
124 pVM->pgm.s.cReusedSharedPages++;
125 }
126 /* else: nothing changed (== this page is now a shared
127 page), so no need to flush anything. */
128
129 pVM->pgm.s.cSharedPages++;
130 pVM->pgm.s.cPrivatePages--;
131 PGM_PAGE_SET_STATE(pVM, pPage, PGM_PAGE_STATE_SHARED);
132
133# ifdef VBOX_STRICT /* check sum hack */
134 pPage->s.u2Unused0 = PageDesc.u32StrictChecksum & 3;
135 pPage->s.u2Unused1 = (PageDesc.u32StrictChecksum >> 8) & 3;
136# endif
137 }
138 }
139 }
140 else
141 {
142 Assert( rc == VINF_SUCCESS
143 || rc == VERR_PAGE_NOT_PRESENT
144 || rc == VERR_PAGE_MAP_LEVEL4_NOT_PRESENT
145 || rc == VERR_PAGE_DIRECTORY_PTR_NOT_PRESENT
146 || rc == VERR_PAGE_TABLE_NOT_PRESENT);
147 rc = VINF_SUCCESS; /* ignore error */
148 }
149
150 idxPage++;
151 GCPtrPage += PAGE_SIZE;
152 cbLeft -= PAGE_SIZE;
153 }
154 }
155
156 /*
157 * Do TLB flushing if necessary.
158 */
159 if (fFlushTLBs)
160 PGM_INVL_ALL_VCPU_TLBS(pVM);
161
162 if (fFlushRemTLBs)
163 for (VMCPUID idCurCpu = 0; idCurCpu < pVM->cCpus; idCurCpu++)
164 CPUMSetChangedFlags(&pVM->aCpus[idCurCpu], CPUM_CHANGED_GLOBAL_TLB_FLUSH);
165
166 return rc;
167}
168#endif /* VBOX_WITH_PAGE_SHARING */
169
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