VirtualBox

source: vbox/trunk/src/VBox/VMM/MMPagePool.cpp@ 16560

Last change on this file since 16560 was 14602, checked in by vboxsync, 16 years ago

MMPagePool: Fixed VMSetError condition.
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File size: 18.4 KB
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1/* $Id: MMPagePool.cpp 14602 2008-11-25 21:55:34Z vboxsync $ */
2/** @file
3 * MM - Memory Manager - Page Pool.
4 */
5
6/*
7 * Copyright (C) 2006-2007 Sun Microsystems, Inc.
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 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
18 * Clara, CA 95054 USA or visit http://www.sun.com if you need
19 * additional information or have any questions.
20 */
21
22/*******************************************************************************
23* Header Files *
24*******************************************************************************/
25#define LOG_GROUP LOG_GROUP_MM_POOL
26#include <VBox/mm.h>
27#include <VBox/pgm.h>
28#include <VBox/stam.h>
29#include "MMInternal.h"
30#include <VBox/vm.h>
31#include <VBox/param.h>
32#include <VBox/err.h>
33#include <VBox/log.h>
34#include <iprt/alloc.h>
35#include <iprt/assert.h>
36#define USE_INLINE_ASM_BIT_OPS
37#ifdef USE_INLINE_ASM_BIT_OPS
38# include <iprt/asm.h>
39#endif
40#include <iprt/string.h>
41
42
43
44/*******************************************************************************
45* Internal Functions *
46*******************************************************************************/
47#ifdef IN_RING3
48static void * mmR3PagePoolAlloc(PMMPAGEPOOL pPool);
49static void mmR3PagePoolFree(PMMPAGEPOOL pPool, void *pv);
50#endif
51
52
53/**
54 * Initializes the page pool
55 *
56 * @return VBox status.
57 * @param pVM VM handle.
58 * @thread The Emulation Thread.
59 */
60int mmR3PagePoolInit(PVM pVM)
61{
62 AssertMsg(!pVM->mm.s.pPagePoolR3, ("Already initialized!\n"));
63
64 /*
65 * Allocate the pool structures.
66 */
67 /** @todo @bufref{1865},@bufref{3202}: mapping the page pool page into
68 * ring-0. Need to change the wasy we allocate it... */
69 AssertReleaseReturn(sizeof(*pVM->mm.s.pPagePoolR3) + sizeof(*pVM->mm.s.pPagePoolLowR3) < PAGE_SIZE, VERR_INTERNAL_ERROR);
70 int rc = SUPPageAllocLockedEx(1, (void **)&pVM->mm.s.pPagePoolR3, NULL);
71 if (RT_FAILURE(rc))
72 return rc;
73 memset(pVM->mm.s.pPagePoolR3, 0, PAGE_SIZE);
74 pVM->mm.s.pPagePoolR3->pVM = pVM;
75 STAM_REG(pVM, &pVM->mm.s.pPagePoolR3->cPages, STAMTYPE_U32, "/MM/Page/Def/cPages", STAMUNIT_PAGES, "Number of pages in the default pool.");
76 STAM_REG(pVM, &pVM->mm.s.pPagePoolR3->cFreePages, STAMTYPE_U32, "/MM/Page/Def/cFreePages", STAMUNIT_PAGES, "Number of free pages in the default pool.");
77 STAM_REG(pVM, &pVM->mm.s.pPagePoolR3->cSubPools, STAMTYPE_U32, "/MM/Page/Def/cSubPools", STAMUNIT_COUNT, "Number of sub pools in the default pool.");
78 STAM_REG(pVM, &pVM->mm.s.pPagePoolR3->cAllocCalls, STAMTYPE_COUNTER, "/MM/Page/Def/cAllocCalls", STAMUNIT_CALLS, "Number of MMR3PageAlloc() calls for the default pool.");
79 STAM_REG(pVM, &pVM->mm.s.pPagePoolR3->cFreeCalls, STAMTYPE_COUNTER, "/MM/Page/Def/cFreeCalls", STAMUNIT_CALLS, "Number of MMR3PageFree()+MMR3PageFreeByPhys() calls for the default pool.");
80 STAM_REG(pVM, &pVM->mm.s.pPagePoolR3->cToPhysCalls, STAMTYPE_COUNTER, "/MM/Page/Def/cToPhysCalls", STAMUNIT_CALLS, "Number of MMR3Page2Phys() calls for this pool.");
81 STAM_REG(pVM, &pVM->mm.s.pPagePoolR3->cToVirtCalls, STAMTYPE_COUNTER, "/MM/Page/Def/cToVirtCalls", STAMUNIT_CALLS, "Number of MMR3PagePhys2Page()+MMR3PageFreeByPhys() calls for the default pool.");
82 STAM_REG(pVM, &pVM->mm.s.pPagePoolR3->cErrors, STAMTYPE_COUNTER, "/MM/Page/Def/cErrors", STAMUNIT_ERRORS,"Number of errors for the default pool.");
83
84 pVM->mm.s.pPagePoolLowR3 = pVM->mm.s.pPagePoolR3 + 1;
85 pVM->mm.s.pPagePoolLowR3->pVM = pVM;
86 pVM->mm.s.pPagePoolLowR3->fLow = true;
87 STAM_REG(pVM, &pVM->mm.s.pPagePoolLowR3->cPages, STAMTYPE_U32, "/MM/Page/Low/cPages", STAMUNIT_PAGES, "Number of pages in the <4GB pool.");
88 STAM_REG(pVM, &pVM->mm.s.pPagePoolLowR3->cFreePages, STAMTYPE_U32, "/MM/Page/Low/cFreePages", STAMUNIT_PAGES, "Number of free pages in the <4GB pool.");
89 STAM_REG(pVM, &pVM->mm.s.pPagePoolLowR3->cSubPools, STAMTYPE_U32, "/MM/Page/Low/cSubPools", STAMUNIT_COUNT, "Number of sub pools in the <4GB pool.");
90 STAM_REG(pVM, &pVM->mm.s.pPagePoolLowR3->cAllocCalls, STAMTYPE_COUNTER, "/MM/Page/Low/cAllocCalls", STAMUNIT_CALLS, "Number of MMR3PageAllocLow() calls for the <4GB pool.");
91 STAM_REG(pVM, &pVM->mm.s.pPagePoolLowR3->cFreeCalls, STAMTYPE_COUNTER, "/MM/Page/Low/cFreeCalls", STAMUNIT_CALLS, "Number of MMR3PageFreeLow()+MMR3PageFreeByPhys() calls for the <4GB pool.");
92 STAM_REG(pVM, &pVM->mm.s.pPagePoolLowR3->cToPhysCalls,STAMTYPE_COUNTER, "/MM/Page/Low/cToPhysCalls", STAMUNIT_CALLS, "Number of MMR3Page2Phys() calls for the <4GB pool.");
93 STAM_REG(pVM, &pVM->mm.s.pPagePoolLowR3->cToVirtCalls,STAMTYPE_COUNTER, "/MM/Page/Low/cToVirtCalls", STAMUNIT_CALLS, "Number of MMR3PagePhys2Page()+MMR3PageFreeByPhys() calls for the <4GB pool.");
94 STAM_REG(pVM, &pVM->mm.s.pPagePoolLowR3->cErrors, STAMTYPE_COUNTER, "/MM/Page/Low/cErrors", STAMUNIT_ERRORS,"Number of errors for the <4GB pool.");
95
96#ifndef VBOX_WITH_2X_4GB_ADDR_SPACE
97 pVM->mm.s.pPagePoolR0 = (uintptr_t)pVM->mm.s.pPagePoolR3;
98 pVM->mm.s.pPagePoolLowR0 = (uintptr_t)pVM->mm.s.pPagePoolLowR3;
99#endif
100
101 /** @todo init a mutex? */
102 return VINF_SUCCESS;
103}
104
105
106/**
107 * Release all locks and free the allocated memory.
108 *
109 * @param pVM VM handle.
110 * @thread The Emulation Thread.
111 */
112void mmR3PagePoolTerm(PVM pVM)
113{
114 if (pVM->mm.s.pPagePoolR3)
115 {
116 /*
117 * Unlock all memory held by subpools and free the memory.
118 * (The MM Heap will free the memory used for internal stuff.)
119 */
120 Assert(!pVM->mm.s.pPagePoolR3->fLow);
121 PMMPAGESUBPOOL pSubPool = pVM->mm.s.pPagePoolR3->pHead;
122 while (pSubPool)
123 {
124 int rc = SUPR3PageFreeEx(pSubPool->pvPages, pSubPool->cPages);
125 AssertMsgRC(rc, ("SUPPageFree(%p) failed with rc=%Rrc\n", pSubPool->pvPages, rc));
126 pSubPool->pvPages = NULL;
127
128 /* next */
129 pSubPool = pSubPool->pNext;
130 }
131 pVM->mm.s.pPagePoolR3 = NULL;
132#ifndef VBOX_WITH_2X_4GB_ADDR_SPACE
133 pVM->mm.s.pPagePoolR0 = NIL_RTR0PTR;
134#endif
135 }
136
137 if (pVM->mm.s.pPagePoolLowR3)
138 {
139 /*
140 * Free the memory.
141 */
142 Assert(pVM->mm.s.pPagePoolLowR3->fLow);
143 PMMPAGESUBPOOL pSubPool = pVM->mm.s.pPagePoolLowR3->pHead;
144 while (pSubPool)
145 {
146 int rc = SUPLowFree(pSubPool->pvPages, pSubPool->cPages);
147 AssertMsgRC(rc, ("SUPPageFree(%p) failed with rc=%d\n", pSubPool->pvPages, rc));
148 pSubPool->pvPages = NULL;
149
150 /* next */
151 pSubPool = pSubPool->pNext;
152 }
153 pVM->mm.s.pPagePoolLowR3 = NULL;
154#ifndef VBOX_WITH_2X_4GB_ADDR_SPACE
155 pVM->mm.s.pPagePoolLowR0 = NIL_RTR0PTR;
156#endif
157 }
158}
159
160
161/**
162 * Allocates a page from the page pool.
163 *
164 * @returns Pointer to allocated page(s).
165 * @returns NULL on failure.
166 * @param pPool Pointer to the page pool.
167 * @thread The Emulation Thread.
168 */
169DECLINLINE(void *) mmR3PagePoolAlloc(PMMPAGEPOOL pPool)
170{
171 VM_ASSERT_EMT(pPool->pVM);
172 STAM_COUNTER_INC(&pPool->cAllocCalls);
173
174 /*
175 * Walk free list.
176 */
177 if (pPool->pHeadFree)
178 {
179 PMMPAGESUBPOOL pSub = pPool->pHeadFree;
180 /* decrement free count and unlink if no more free entries. */
181 if (!--pSub->cPagesFree)
182 pPool->pHeadFree = pSub->pNextFree;
183#ifdef VBOX_WITH_STATISTICS
184 pPool->cFreePages--;
185#endif
186
187 /* find free spot in bitmap. */
188#ifdef USE_INLINE_ASM_BIT_OPS
189 const int iPage = ASMBitFirstClear(pSub->auBitmap, pSub->cPages);
190 if (iPage >= 0)
191 {
192 Assert(!ASMBitTest(pSub->auBitmap, iPage));
193 ASMBitSet(pSub->auBitmap, iPage);
194 return (uint8_t *)pSub->pvPages + PAGE_SIZE * iPage;
195 }
196#else
197 unsigned *pu = &pSub->auBitmap[0];
198 unsigned *puEnd = &pSub->auBitmap[pSub->cPages / (sizeof(pSub->auBitmap) * 8)];
199 while (pu < puEnd)
200 {
201 unsigned u;
202 if ((u = *pu) != ~0U)
203 {
204 unsigned iBit = 0;
205 unsigned uMask = 1;
206 while (iBit < sizeof(pSub->auBitmap[0]) * 8)
207 {
208 if (!(u & uMask))
209 {
210 *pu |= uMask;
211 return (uint8_t *)pSub->pvPages
212 + PAGE_SIZE * (iBit + ((uint8_t *)pu - (uint8_t *)&pSub->auBitmap[0]) * 8);
213 }
214 iBit++;
215 uMask <<= 1;
216 }
217 STAM_COUNTER_INC(&pPool->cErrors);
218 AssertMsgFailed(("how odd, expected to find a free bit in %#x, but didn't\n", u));
219 }
220 /* next */
221 pu++;
222 }
223#endif
224 STAM_COUNTER_INC(&pPool->cErrors);
225#ifdef VBOX_WITH_STATISTICS
226 pPool->cFreePages++;
227#endif
228 AssertMsgFailed(("how strange, expected to find a free bit in %p, but didn't (%d pages supposed to be free!)\n", pSub, pSub->cPagesFree + 1));
229 }
230
231 /*
232 * Allocate new subpool.
233 */
234 unsigned cPages = !pPool->fLow ? 128 : 32;
235 PMMPAGESUBPOOL pSub;
236 int rc = MMHyperAlloc(pPool->pVM,
237 RT_OFFSETOF(MMPAGESUBPOOL, auBitmap[cPages / (sizeof(pSub->auBitmap[0] * 8))])
238 + (sizeof(SUPPAGE) + sizeof(MMPPLOOKUPHCPHYS)) * cPages
239 + sizeof(MMPPLOOKUPHCPTR),
240 0,
241 MM_TAG_MM_PAGE,
242 (void **)&pSub);
243 if (RT_FAILURE(rc))
244 return NULL;
245
246 PSUPPAGE paPhysPages = (PSUPPAGE)&pSub->auBitmap[cPages / (sizeof(pSub->auBitmap[0]) * 8)];
247 Assert((uintptr_t)paPhysPages >= (uintptr_t)&pSub->auBitmap[1]);
248 if (!pPool->fLow)
249 {
250 rc = SUPR3PageAllocEx(cPages,
251 0 /* fFlags */,
252 &pSub->pvPages,
253 NULL,
254 paPhysPages);
255 if (RT_FAILURE(rc))
256 rc = VMSetError(pPool->pVM, rc, RT_SRC_POS,
257 N_("Failed to lock host %zd bytes of memory (out of memory)"), (size_t)cPages << PAGE_SHIFT);
258 }
259 else
260 rc = SUPLowAlloc(cPages, &pSub->pvPages, NULL, paPhysPages);
261 if (RT_SUCCESS(rc))
262 {
263 /*
264 * Setup the sub structure and allocate the requested page.
265 */
266 pSub->cPages = cPages;
267 pSub->cPagesFree= cPages - 1;
268 pSub->paPhysPages = paPhysPages;
269 memset(pSub->auBitmap, 0, cPages / 8);
270 /* allocate first page. */
271 pSub->auBitmap[0] |= 1;
272 /* link into free chain. */
273 pSub->pNextFree = pPool->pHeadFree;
274 pPool->pHeadFree= pSub;
275 /* link into main chain. */
276 pSub->pNext = pPool->pHead;
277 pPool->pHead = pSub;
278 /* update pool statistics. */
279 pPool->cSubPools++;
280 pPool->cPages += cPages;
281#ifdef VBOX_WITH_STATISTICS
282 pPool->cFreePages += cPages - 1;
283#endif
284
285 /*
286 * Initialize the physical pages with backpointer to subpool.
287 */
288 unsigned i = cPages;
289 while (i-- > 0)
290 {
291 AssertMsg(paPhysPages[i].Phys && !(paPhysPages[i].Phys & PAGE_OFFSET_MASK),
292 ("i=%d Phys=%d\n", i, paPhysPages[i].Phys));
293 paPhysPages[i].uReserved = (RTHCUINTPTR)pSub;
294 }
295
296 /*
297 * Initialize the physical lookup record with backpointers to the physical pages.
298 */
299 PMMPPLOOKUPHCPHYS paLookupPhys = (PMMPPLOOKUPHCPHYS)&paPhysPages[cPages];
300 i = cPages;
301 while (i-- > 0)
302 {
303 paLookupPhys[i].pPhysPage = &paPhysPages[i];
304 paLookupPhys[i].Core.Key = paPhysPages[i].Phys;
305 RTAvlHCPhysInsert(&pPool->pLookupPhys, &paLookupPhys[i].Core);
306 }
307
308 /*
309 * And the one record for virtual memory lookup.
310 */
311 PMMPPLOOKUPHCPTR pLookupVirt = (PMMPPLOOKUPHCPTR)&paLookupPhys[cPages];
312 pLookupVirt->pSubPool = pSub;
313 pLookupVirt->Core.Key = pSub->pvPages;
314 RTAvlPVInsert(&pPool->pLookupVirt, &pLookupVirt->Core);
315
316 /* return allocated page (first). */
317 return pSub->pvPages;
318 }
319
320 MMR3HeapFree(pSub);
321 STAM_COUNTER_INC(&pPool->cErrors);
322 if (pPool->fLow)
323 VMSetError(pPool->pVM, rc, RT_SRC_POS,
324 N_("Failed to expand page pool for memory below 4GB. current size: %d pages"),
325 pPool->cPages);
326 AssertMsgFailed(("Failed to expand pool%s. rc=%Rrc poolsize=%d\n",
327 pPool->fLow ? " (<4GB)" : "", rc, pPool->cPages));
328 return NULL;
329}
330
331
332/**
333 * Frees a page from the page pool.
334 *
335 * @param pPool Pointer to the page pool.
336 * @param pv Pointer to the page to free.
337 * I.e. pointer returned by mmR3PagePoolAlloc().
338 * @thread The Emulation Thread.
339 */
340DECLINLINE(void) mmR3PagePoolFree(PMMPAGEPOOL pPool, void *pv)
341{
342 VM_ASSERT_EMT(pPool->pVM);
343 STAM_COUNTER_INC(&pPool->cFreeCalls);
344
345 /*
346 * Lookup the virtual address.
347 */
348 PMMPPLOOKUPHCPTR pLookup = (PMMPPLOOKUPHCPTR)RTAvlPVGetBestFit(&pPool->pLookupVirt, pv, false);
349 if ( !pLookup
350 || (uint8_t *)pv >= (uint8_t *)pLookup->pSubPool->pvPages + (pLookup->pSubPool->cPages << PAGE_SHIFT)
351 )
352 {
353 STAM_COUNTER_INC(&pPool->cErrors);
354 AssertMsgFailed(("invalid pointer %p\n", pv));
355 return;
356 }
357
358 /*
359 * Free the page.
360 */
361 PMMPAGESUBPOOL pSubPool = pLookup->pSubPool;
362 /* clear bitmap bit */
363 const unsigned iPage = ((uint8_t *)pv - (uint8_t *)pSubPool->pvPages) >> PAGE_SHIFT;
364#ifdef USE_INLINE_ASM_BIT_OPS
365 Assert(ASMBitTest(pSubPool->auBitmap, iPage));
366 ASMBitClear(pSubPool->auBitmap, iPage);
367#else
368 unsigned iBit = iPage % (sizeof(pSubPool->auBitmap[0]) * 8);
369 unsigned iIndex = iPage / (sizeof(pSubPool->auBitmap[0]) * 8);
370 pSubPool->auBitmap[iIndex] &= ~(1 << iBit);
371#endif
372 /* update stats. */
373 pSubPool->cPagesFree++;
374#ifdef VBOX_WITH_STATISTICS
375 pPool->cFreePages++;
376#endif
377 if (pSubPool->cPagesFree == 1)
378 {
379 pSubPool->pNextFree = pPool->pHeadFree;
380 pPool->pHeadFree = pSubPool;
381 }
382}
383
384
385/**
386 * Allocates a page from the page pool.
387 *
388 * This function may returns pages which has physical addresses any
389 * where. If you require a page to be within the first 4GB of physical
390 * memory, use MMR3PageAllocLow().
391 *
392 * @returns Pointer to the allocated page page.
393 * @returns NULL on failure.
394 * @param pVM VM handle.
395 * @thread The Emulation Thread.
396 */
397VMMR3DECL(void *) MMR3PageAlloc(PVM pVM)
398{
399 return mmR3PagePoolAlloc(pVM->mm.s.pPagePoolR3);
400}
401
402
403/**
404 * Allocates a page from the page pool and return its physical address.
405 *
406 * This function may returns pages which has physical addresses any
407 * where. If you require a page to be within the first 4GB of physical
408 * memory, use MMR3PageAllocLow().
409 *
410 * @returns Pointer to the allocated page page.
411 * @returns NIL_RTHCPHYS on failure.
412 * @param pVM VM handle.
413 * @thread The Emulation Thread.
414 */
415VMMR3DECL(RTHCPHYS) MMR3PageAllocPhys(PVM pVM)
416{
417 /** @todo optimize this, it's the most common case now. */
418 void *pv = mmR3PagePoolAlloc(pVM->mm.s.pPagePoolR3);
419 if (pv)
420 return mmPagePoolPtr2Phys(pVM->mm.s.pPagePoolR3, pv);
421 return NIL_RTHCPHYS;
422}
423
424
425/**
426 * Frees a page allocated from the page pool by MMR3PageAlloc() or
427 * MMR3PageAllocPhys().
428 *
429 * @param pVM VM handle.
430 * @param pvPage Pointer to the page.
431 * @thread The Emulation Thread.
432 */
433VMMR3DECL(void) MMR3PageFree(PVM pVM, void *pvPage)
434{
435 mmR3PagePoolFree(pVM->mm.s.pPagePoolR3, pvPage);
436}
437
438
439/**
440 * Allocates a page from the low page pool.
441 *
442 * @returns Pointer to the allocated page.
443 * @returns NULL on failure.
444 * @param pVM VM handle.
445 * @thread The Emulation Thread.
446 */
447VMMR3DECL(void *) MMR3PageAllocLow(PVM pVM)
448{
449 return mmR3PagePoolAlloc(pVM->mm.s.pPagePoolLowR3);
450}
451
452
453/**
454 * Frees a page allocated from the page pool by MMR3PageAllocLow().
455 *
456 * @param pVM VM handle.
457 * @param pvPage Pointer to the page.
458 * @thread The Emulation Thread.
459 */
460VMMR3DECL(void) MMR3PageFreeLow(PVM pVM, void *pvPage)
461{
462 mmR3PagePoolFree(pVM->mm.s.pPagePoolLowR3, pvPage);
463}
464
465
466/**
467 * Free a page allocated from the page pool by physical address.
468 * This works for pages allocated by MMR3PageAlloc(), MMR3PageAllocPhys()
469 * and MMR3PageAllocLow().
470 *
471 * @param pVM VM handle.
472 * @param HCPhysPage The physical address of the page to be freed.
473 * @thread The Emulation Thread.
474 */
475VMMR3DECL(void) MMR3PageFreeByPhys(PVM pVM, RTHCPHYS HCPhysPage)
476{
477 void *pvPage = mmPagePoolPhys2Ptr(pVM->mm.s.pPagePoolR3, HCPhysPage);
478 if (!pvPage)
479 pvPage = mmPagePoolPhys2Ptr(pVM->mm.s.pPagePoolLowR3, HCPhysPage);
480 if (pvPage)
481 mmR3PagePoolFree(pVM->mm.s.pPagePoolR3, pvPage);
482 else
483 AssertMsgFailed(("Invalid address HCPhysPT=%#x\n", HCPhysPage));
484}
485
486
487/**
488 * Gets the HC pointer to the dummy page.
489 *
490 * The dummy page is used as a place holder to prevent potential bugs
491 * from doing really bad things to the system.
492 *
493 * @returns Pointer to the dummy page.
494 * @param pVM VM handle.
495 * @thread The Emulation Thread.
496 */
497VMMR3DECL(void *) MMR3PageDummyHCPtr(PVM pVM)
498{
499 VM_ASSERT_EMT(pVM);
500 if (!pVM->mm.s.pvDummyPage)
501 {
502 pVM->mm.s.pvDummyPage = mmR3PagePoolAlloc(pVM->mm.s.pPagePoolR3);
503 AssertRelease(pVM->mm.s.pvDummyPage);
504 pVM->mm.s.HCPhysDummyPage = mmPagePoolPtr2Phys(pVM->mm.s.pPagePoolR3, pVM->mm.s.pvDummyPage);
505 AssertRelease(!(pVM->mm.s.HCPhysDummyPage & ~X86_PTE_PAE_PG_MASK));
506 }
507 return pVM->mm.s.pvDummyPage;
508}
509
510
511/**
512 * Gets the HC Phys to the dummy page.
513 *
514 * The dummy page is used as a place holder to prevent potential bugs
515 * from doing really bad things to the system.
516 *
517 * @returns Pointer to the dummy page.
518 * @param pVM VM handle.
519 * @thread The Emulation Thread.
520 */
521VMMR3DECL(RTHCPHYS) MMR3PageDummyHCPhys(PVM pVM)
522{
523 VM_ASSERT_EMT(pVM);
524 if (!pVM->mm.s.pvDummyPage)
525 MMR3PageDummyHCPtr(pVM);
526 return pVM->mm.s.HCPhysDummyPage;
527}
528
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