2 * This file is part of the Palacios Virtual Machine Monitor developed
3 * by the V3VEE Project with funding from the United States National
4 * Science Foundation and the Department of Energy.
6 * The V3VEE Project is a joint project between Northwestern University
7 * and the University of New Mexico. You can find out more at
10 * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu>
11 * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org>
12 * All rights reserved.
14 * Author: Jack Lange <jarusl@cs.northwestern.edu>
16 * This is free software. You are permitted to use,
17 * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
21 #include <palacios/vmm_shadow_paging.h>
24 #include <palacios/vmm.h>
25 #include <palacios/vm_guest_mem.h>
26 #include <palacios/vmm_decoder.h>
28 #ifndef DEBUG_SHADOW_PAGING
30 #define PrintDebug(fmt, args...)
42 DEFINE_HASHTABLE_INSERT(add_cr3_to_cache, addr_t, struct hashtable *);
43 DEFINE_HASHTABLE_SEARCH(find_cr3_in_cache, addr_t, struct hashtable *);
44 DEFINE_HASHTABLE_REMOVE(del_cr3_from_cache, addr_t, struct hashtable *, 0);
47 DEFINE_HASHTABLE_INSERT(add_pte_map, addr_t, addr_t);
48 DEFINE_HASHTABLE_SEARCH(find_pte_map, addr_t, addr_t);
49 DEFINE_HASHTABLE_REMOVE(del_pte_map, addr_t, addr_t, 0);
54 static uint_t pte_hash_fn(addr_t key) {
55 return hash_long(key, 32);
58 static int pte_equals(addr_t key1, addr_t key2) {
59 return (key1 == key2);
62 static uint_t cr3_hash_fn(addr_t key) {
63 return hash_long(key, 32);
66 static int cr3_equals(addr_t key1, addr_t key2) {
67 return (key1 == key2);
71 static int handle_shadow_pte32_fault(struct guest_info* info,
73 pf_error_t error_code,
77 static int handle_shadow_pagefault32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code);
79 int v3_init_shadow_page_state(struct guest_info * info) {
80 struct shadow_page_state * state = &(info->shdw_pg_state);
83 state->shadow_cr3 = 0;
86 state->cr3_cache = create_hashtable(0, &cr3_hash_fn, &cr3_equals);
88 state->cached_cr3 = 0;
89 state->cached_ptes = NULL;
98 For now we'll do something a little more lightweight
99 int cache_page_tables32(struct guest_info * info, addr_t pde) {
100 struct shadow_page_state * state = &(info->shdw_pg_state);
101 addr_t pde_host_addr;
103 struct hashtable * pte_cache = NULL;
107 pte_cache = (struct hashtable *)find_cr3_in_cache(state->cr3_cache, pde);
108 if (pte_cache != NULL) {
109 PrintError("CR3 already present in cache\n");
110 state->current_ptes = pte_cache;
113 PrintError("Creating new CR3 cache entry\n");
114 pte_cache = create_hashtable(0, &pte_hash_fn, &pte_equals);
115 state->current_ptes = pte_cache;
116 add_cr3_to_cache(state->cr3_cache, pde, pte_cache);
119 if (guest_pa_to_host_va(info, pde, &pde_host_addr) == -1) {
120 PrintError("Could not lookup host address of guest PDE\n");
124 tmp_pde = (pde32_t *)pde_host_addr;
126 add_pte_map(pte_cache, pde, pde_host_addr);
129 for (i = 0; i < MAX_PDE32_ENTRIES; i++) {
130 if ((tmp_pde[i].present) && (tmp_pde[i].large_page == 0)) {
131 addr_t pte_host_addr;
133 if (guest_pa_to_host_va(info, (addr_t)(PDE32_T_ADDR(tmp_pde[i])), &pte_host_addr) == -1) {
134 PrintError("Could not lookup host address of guest PDE\n");
138 add_pte_map(pte_cache, (addr_t)(PDE32_T_ADDR(tmp_pde[i])), pte_host_addr);
147 int v3_cache_page_tables32(struct guest_info * info, addr_t pde) {
148 struct shadow_page_state * state = &(info->shdw_pg_state);
149 addr_t pde_host_addr;
151 struct hashtable * pte_cache = NULL;
154 if (pde == state->cached_cr3) {
158 if (state->cached_ptes != NULL) {
159 hashtable_destroy(state->cached_ptes, 0, 0);
160 state->cached_ptes = NULL;
163 state->cached_cr3 = pde;
165 pte_cache = create_hashtable(0, &pte_hash_fn, &pte_equals);
166 state->cached_ptes = pte_cache;
168 if (guest_pa_to_host_pa(info, pde, &pde_host_addr) == -1) {
169 PrintError("Could not lookup host address of guest PDE\n");
173 tmp_pde = (pde32_t *)pde_host_addr;
175 add_pte_map(pte_cache, pde, pde_host_addr);
178 for (i = 0; i < MAX_PDE32_ENTRIES; i++) {
179 if ((tmp_pde[i].present) && (tmp_pde[i].large_page == 0)) {
180 addr_t pte_host_addr;
182 if (guest_pa_to_host_pa(info, (addr_t)(PDE32_T_ADDR(tmp_pde[i])), &pte_host_addr) == -1) {
183 PrintError("Could not lookup host address of guest PDE\n");
187 add_pte_map(pte_cache, (addr_t)(PDE32_T_ADDR(tmp_pde[i])), pte_host_addr);
197 int v3_replace_shdw_page32(struct guest_info * info, addr_t location, pte32_t * new_page, pte32_t * old_page) {
198 pde32_t * shadow_pd = (pde32_t *)CR3_TO_PDE32(info->shdw_pg_state.shadow_cr3);
199 pde32_t * shadow_pde = (pde32_t *)&(shadow_pd[PDE32_INDEX(location)]);
201 if (shadow_pde->large_page == 0) {
202 pte32_t * shadow_pt = (pte32_t *)(addr_t)PDE32_T_ADDR((*shadow_pde));
203 pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(location)]);
205 //if (shadow_pte->present == 1) {
206 *(uint_t *)old_page = *(uint_t *)shadow_pte;
209 *(uint_t *)shadow_pte = *(uint_t *)new_page;
212 // currently unhandled
224 int v3_handle_shadow_pagefault(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
226 if (info->mem_mode == PHYSICAL_MEM) {
227 // If paging is not turned on we need to handle the special cases
228 return handle_special_page_fault(info, fault_addr, fault_addr, error_code);
229 } else if (info->mem_mode == VIRTUAL_MEM) {
231 switch (info->cpu_mode) {
233 return handle_shadow_pagefault32(info, fault_addr, error_code);
238 PrintError("Unhandled CPU Mode\n");
242 PrintError("Invalid Memory mode\n");
247 addr_t v3_create_new_shadow_pt32() {
250 host_pde = V3_AllocPages(1);
251 memset(host_pde, 0, PAGE_SIZE);
253 return (addr_t)host_pde;
257 static void inject_guest_pf(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
258 info->ctrl_regs.cr2 = fault_addr;
259 v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code);
263 static int is_guest_pf(pt_access_status_t guest_access, pt_access_status_t shadow_access) {
264 /* basically the reasoning is that there can be multiple reasons for a page fault:
265 If there is a permissions failure for a page present in the guest _BUT_
266 the reason for the fault was that the page is not present in the shadow,
267 _THEN_ we have to map the shadow page in and reexecute, this will generate
268 a permissions fault which is _THEN_ valid to send to the guest
269 _UNLESS_ both the guest and shadow have marked the page as not present
273 if (guest_access != PT_ACCESS_OK) {
274 // Guest Access Error
276 if ((shadow_access != PT_ENTRY_NOT_PRESENT) &&
277 (guest_access != PT_ENTRY_NOT_PRESENT)) {
278 // aka (guest permission error)
282 if ((shadow_access == PT_ENTRY_NOT_PRESENT) &&
283 (guest_access == PT_ENTRY_NOT_PRESENT)) {
284 // Page tables completely blank, handle guest first
288 // Otherwise we'll handle the guest fault later...?
297 /* The guest status checks have already been done,
298 * only special case shadow checks remain
300 static int handle_large_pagefault32(struct guest_info * info,
301 addr_t fault_addr, pf_error_t error_code,
302 pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde)
304 pt_access_status_t shadow_pte_access = can_access_pte32(shadow_pt, fault_addr, error_code);
305 pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(fault_addr)]);
307 if (shadow_pte_access == PT_ACCESS_OK) {
308 // Inconsistent state...
309 // Guest Re-Entry will flush tables and everything should now workd
310 PrintDebug("Inconsistent state... Guest re-entry should flush tlb\n");
315 if (shadow_pte_access == PT_ENTRY_NOT_PRESENT) {
316 // Get the guest physical address of the fault
317 addr_t guest_fault_pa = PDE32_4MB_T_ADDR(*large_guest_pde) + PD32_4MB_PAGE_OFFSET(fault_addr);
318 host_region_type_t host_page_type = get_shadow_addr_type(info, guest_fault_pa);
321 if (host_page_type == HOST_REGION_INVALID) {
322 // Inject a machine check in the guest
323 PrintDebug("Invalid Guest Address in page table (0x%x)\n", guest_fault_pa);
324 v3_raise_exception(info, MC_EXCEPTION);
328 if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) {
329 struct shadow_page_state * state = &(info->shdw_pg_state);
330 addr_t shadow_pa = get_shadow_addr(info, guest_fault_pa);
332 shadow_pte->page_base_addr = PT32_BASE_ADDR(shadow_pa);
334 shadow_pte->present = 1;
336 /* We are assuming that the PDE entry has precedence
337 * so the Shadow PDE will mirror the guest PDE settings,
338 * and we don't have to worry about them here
341 shadow_pte->user_page = 1;
343 if (find_pte_map(state->cached_ptes, PT32_PAGE_ADDR(guest_fault_pa)) != NULL) {
344 // Check if the entry is a page table...
345 PrintDebug("Marking page as Guest Page Table (large page)\n");
346 shadow_pte->vmm_info = PT32_GUEST_PT;
347 shadow_pte->writable = 0;
349 shadow_pte->writable = 1;
353 //set according to VMM policy
354 shadow_pte->write_through = 0;
355 shadow_pte->cache_disable = 0;
356 shadow_pte->global_page = 0;
360 // Handle hooked pages as well as other special pages
361 if (handle_special_page_fault(info, fault_addr, guest_fault_pa, error_code) == -1) {
362 PrintError("Special Page Fault handler returned error for address: %x\n", fault_addr);
366 } else if ((shadow_pte_access == PT_WRITE_ERROR) &&
367 (shadow_pte->vmm_info == PT32_GUEST_PT)) {
369 struct shadow_page_state * state = &(info->shdw_pg_state);
370 PrintDebug("Write operation on Guest PAge Table Page (large page)\n");
371 state->cached_cr3 = 0;
372 shadow_pte->writable = 1;
375 PrintError("Error in large page fault handler...\n");
376 PrintError("This case should have been handled at the top level handler\n");
380 PrintDebug("Returning from large page fault handler\n");
385 static int handle_shadow_pagefault32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
386 pde32_t * guest_pd = NULL;
387 pde32_t * shadow_pd = (pde32_t *)CR3_TO_PDE32(info->shdw_pg_state.shadow_cr3);
388 addr_t guest_cr3 = CR3_TO_PDE32(info->shdw_pg_state.guest_cr3);
389 pt_access_status_t guest_pde_access;
390 pt_access_status_t shadow_pde_access;
391 pde32_t * guest_pde = NULL;
392 pde32_t * shadow_pde = (pde32_t *)&(shadow_pd[PDE32_INDEX(fault_addr)]);
394 PrintDebug("Shadow page fault handler\n");
396 if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pd) == -1) {
397 PrintError("Invalid Guest PDE Address: 0x%x\n", guest_cr3);
401 guest_pde = (pde32_t *)&(guest_pd[PDE32_INDEX(fault_addr)]);
404 // Check the guest page permissions
405 guest_pde_access = can_access_pde32(guest_pd, fault_addr, error_code);
407 // Check the shadow page permissions
408 shadow_pde_access = can_access_pde32(shadow_pd, fault_addr, error_code);
410 /* Was the page fault caused by the Guest's page tables? */
411 if (is_guest_pf(guest_pde_access, shadow_pde_access) == 1) {
412 PrintDebug("Injecting PDE pf to guest: (guest access error=%d) (pf error code=%d)\n",
413 guest_pde_access, error_code);
414 inject_guest_pf(info, fault_addr, error_code);
419 if (shadow_pde_access == PT_ENTRY_NOT_PRESENT)
421 pte32_t * shadow_pt = (pte32_t *)v3_create_new_shadow_pt32();
423 shadow_pde->present = 1;
424 shadow_pde->user_page = guest_pde->user_page;
425 // shadow_pde->large_page = guest_pde->large_page;
426 shadow_pde->large_page = 0;
429 // VMM Specific options
430 shadow_pde->write_through = 0;
431 shadow_pde->cache_disable = 0;
432 shadow_pde->global_page = 0;
435 guest_pde->accessed = 1;
437 shadow_pde->pt_base_addr = PD32_BASE_ADDR((addr_t)shadow_pt);
439 if (guest_pde->large_page == 0) {
440 shadow_pde->writable = guest_pde->writable;
442 ((pde32_4MB_t *)guest_pde)->dirty = 0;
443 shadow_pde->writable = 0;
446 else if (shadow_pde_access == PT_ACCESS_OK)
451 pte32_t * shadow_pt = (pte32_t *)(addr_t)PDE32_T_ADDR((*shadow_pde));
453 if (guest_pde->large_page == 0) {
454 pte32_t * guest_pt = NULL;
455 if (guest_pa_to_host_va(info, PDE32_T_ADDR((*guest_pde)), (addr_t*)&guest_pt) == -1) {
456 // Machine check the guest
457 PrintDebug("Invalid Guest PTE Address: 0x%x\n", PDE32_T_ADDR((*guest_pde)));
458 v3_raise_exception(info, MC_EXCEPTION);
462 if (handle_shadow_pte32_fault(info, fault_addr, error_code, shadow_pt, guest_pt) == -1) {
463 PrintError("Error handling Page fault caused by PTE\n");
466 } else if (guest_pde->large_page == 1) {
467 if (handle_large_pagefault32(info, fault_addr, error_code, shadow_pt, (pde32_4MB_t *)guest_pde) == -1) {
468 PrintError("Error handling large pagefault\n");
473 else if ((shadow_pde_access == PT_WRITE_ERROR) &&
474 (guest_pde->large_page == 1) &&
475 (((pde32_4MB_t *)guest_pde)->dirty == 0))
478 // Page Directory Entry marked read-only
479 // Its a large page and we need to update the dirty bit in the guest
482 PrintDebug("Large page write error... Setting dirty bit and returning\n");
483 ((pde32_4MB_t *)guest_pde)->dirty = 1;
484 shadow_pde->writable = guest_pde->writable;
488 else if (shadow_pde_access == PT_USER_ERROR)
491 // Page Directory Entry marked non-user
493 PrintDebug("Shadow Paging User access error (shadow_pde_access=0x%x, guest_pde_access=0x%x)\n",
494 shadow_pde_access, guest_pde_access);
495 inject_guest_pf(info, fault_addr, error_code);
500 // inject page fault in guest
501 inject_guest_pf(info, fault_addr, error_code);
502 PrintDebug("Unknown Error occurred (shadow_pde_access=%d)\n", shadow_pde_access);
503 PrintDebug("Manual Says to inject page fault into guest\n");
504 #ifdef DEBUG_SHADOW_PAGING
505 PrintDebug("Guest PDE: (access=%d)\n\t", guest_pde_access);
506 PrintPDE32(fault_addr, guest_pde);
507 PrintDebug("Shadow PDE: (access=%d)\n\t", shadow_pde_access);
508 PrintPDE32(fault_addr, shadow_pde);
514 PrintDebug("Returning end of PDE function (rip=%x)\n", info->rip);
521 * We assume the the guest pte pointer has already been translated to a host virtual address
523 static int handle_shadow_pte32_fault(struct guest_info * info,
525 pf_error_t error_code,
527 pte32_t * guest_pt) {
529 pt_access_status_t guest_pte_access;
530 pt_access_status_t shadow_pte_access;
531 pte32_t * guest_pte = (pte32_t *)&(guest_pt[PTE32_INDEX(fault_addr)]);;
532 pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(fault_addr)]);
535 // Check the guest page permissions
536 guest_pte_access = can_access_pte32(guest_pt, fault_addr, error_code);
538 // Check the shadow page permissions
539 shadow_pte_access = can_access_pte32(shadow_pt, fault_addr, error_code);
541 #ifdef DEBUG_SHADOW_PAGING
542 PrintDebug("Guest PTE: (access=%d)\n\t", guest_pte_access);
543 PrintPTE32(fault_addr, guest_pte);
544 PrintDebug("Shadow PTE: (access=%d)\n\t", shadow_pte_access);
545 PrintPTE32(fault_addr, shadow_pte);
548 /* Was the page fault caused by the Guest's page tables? */
549 if (is_guest_pf(guest_pte_access, shadow_pte_access) == 1) {
550 PrintDebug("Access error injecting pf to guest (guest access error=%d) (pf error code=%d)\n",
551 guest_pte_access, *(uint_t*)&error_code);
552 inject_guest_pf(info, fault_addr, error_code);
557 if (shadow_pte_access == PT_ACCESS_OK) {
558 // Inconsistent state...
559 // Guest Re-Entry will flush page tables and everything should now work
560 PrintDebug("Inconsistent state... Guest re-entry should flush tlb\n");
565 if (shadow_pte_access == PT_ENTRY_NOT_PRESENT) {
567 addr_t guest_pa = PTE32_T_ADDR((*guest_pte)) + PT32_PAGE_OFFSET(fault_addr);
569 // Page Table Entry Not Present
571 host_region_type_t host_page_type = get_shadow_addr_type(info, guest_pa);
573 if (host_page_type == HOST_REGION_INVALID) {
574 // Inject a machine check in the guest
575 PrintDebug("Invalid Guest Address in page table (0x%x)\n", guest_pa);
576 v3_raise_exception(info, MC_EXCEPTION);
582 if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) {
583 struct shadow_page_state * state = &(info->shdw_pg_state);
584 addr_t shadow_pa = get_shadow_addr(info, guest_pa);
586 shadow_pte->page_base_addr = PT32_BASE_ADDR(shadow_pa);
588 shadow_pte->present = guest_pte->present;
589 shadow_pte->user_page = guest_pte->user_page;
591 //set according to VMM policy
592 shadow_pte->write_through = 0;
593 shadow_pte->cache_disable = 0;
594 shadow_pte->global_page = 0;
597 guest_pte->accessed = 1;
599 if (find_pte_map(state->cached_ptes, PT32_PAGE_ADDR(guest_pa)) != NULL) {
600 // Check if the entry is a page table...
601 PrintDebug("Marking page as Guest Page Table\n", shadow_pte->writable);
602 shadow_pte->vmm_info = PT32_GUEST_PT;
605 if (guest_pte->dirty == 1) {
606 shadow_pte->writable = guest_pte->writable;
607 } else if ((guest_pte->dirty == 0) && (error_code.write == 1)) {
608 shadow_pte->writable = guest_pte->writable;
609 guest_pte->dirty = 1;
611 if (shadow_pte->vmm_info == PT32_GUEST_PT) {
612 // Well that was quick...
613 struct shadow_page_state * state = &(info->shdw_pg_state);
614 PrintDebug("Immediate Write operation on Guest PAge Table Page\n");
615 state->cached_cr3 = 0;
618 } else if ((guest_pte->dirty = 0) && (error_code.write == 0)) {
619 shadow_pte->writable = 0;
625 // Page fault handled by hook functions
626 if (handle_special_page_fault(info, fault_addr, guest_pa, error_code) == -1) {
627 PrintError("Special Page fault handler returned error for address: %x\n", fault_addr);
632 } else if ((shadow_pte_access == PT_WRITE_ERROR) &&
633 (guest_pte->dirty == 0)) {
635 PrintDebug("Shadow PTE Write Error\n");
636 guest_pte->dirty = 1;
637 shadow_pte->writable = guest_pte->writable;
639 if (shadow_pte->vmm_info == PT32_GUEST_PT) {
640 struct shadow_page_state * state = &(info->shdw_pg_state);
641 PrintDebug("Write operation on Guest PAge Table Page\n");
642 state->cached_cr3 = 0;
648 // Inject page fault into the guest
649 inject_guest_pf(info, fault_addr, error_code);
650 PrintError("PTE Page fault fell through... Not sure if this should ever happen\n");
651 PrintError("Manual Says to inject page fault into guest\n");
655 PrintDebug("Returning end of function\n");
664 /* Currently Does not work with Segmentation!!! */
665 int v3_handle_shadow_invlpg(struct guest_info * info) {
666 if (info->mem_mode != VIRTUAL_MEM) {
667 // Paging must be turned on...
668 // should handle with some sort of fault I think
669 PrintError("ERROR: INVLPG called in non paged mode\n");
674 if (info->cpu_mode == PROTECTED) {
679 ret = read_guest_va_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
681 PrintError("Could not read instruction 0x%x (ret=%d)\n", info->rip, ret);
686 /* Can INVLPG work with Segments?? */
687 while (is_prefix_byte(instr[index])) {
692 if ((instr[index] == (uchar_t)0x0f) &&
693 (instr[index + 1] == (uchar_t)0x01)) {
695 addr_t first_operand;
696 addr_t second_operand;
697 v3_operand_type_t addr_type;
698 addr_t guest_cr3 = CR3_TO_PDE32(info->shdw_pg_state.guest_cr3);
700 pde32_t * guest_pd = NULL;
702 if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pd) == -1) {
703 PrintError("Invalid Guest PDE Address: 0x%x\n", guest_cr3);
712 addr_type = decode_operands32(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG32);
714 if (addr_type == MEM_OPERAND) {
715 pde32_t * shadow_pd = (pde32_t *)CR3_TO_PDE32(info->shdw_pg_state.shadow_cr3);
716 pde32_t * shadow_pde = (pde32_t *)&shadow_pd[PDE32_INDEX(first_operand)];
719 //PrintDebug("PDE Index=%d\n", PDE32_INDEX(first_operand));
720 //PrintDebug("FirstOperand = %x\n", first_operand);
722 PrintDebug("Invalidating page for %x\n", first_operand);
724 guest_pde = (pde32_t *)&(guest_pd[PDE32_INDEX(first_operand)]);
726 if (guest_pde->large_page == 1) {
727 shadow_pde->present = 0;
728 PrintDebug("Invalidating Large Page\n");
731 if (shadow_pde->present == 1) {
732 pte32_t * shadow_pt = (pte32_t *)(addr_t)PDE32_T_ADDR((*shadow_pde));
733 pte32_t * shadow_pte = (pte32_t *)&shadow_pt[PTE32_INDEX(first_operand)];
735 #ifdef DEBUG_SHADOW_PAGING
736 PrintDebug("Setting not present\n");
737 PrintPTE32(first_operand, shadow_pte);
740 shadow_pte->present = 0;
747 PrintError("Invalid Operand type\n");
751 PrintError("invalid Instruction Opcode\n");
752 PrintTraceMemDump(instr, 15);
764 static int create_pd32_nonaligned_4MB_page(struct guest_info * info, pte32_t * pt, addr_t guest_addr, pde32_4MB_t * large_shadow_pde) {
766 pte32_t * pte_cursor;
769 for (i = 0; i < 1024; i++) {
770 guest_pa = guest_addr + (PAGE_SIZE * i);
771 host_region_type_t host_page_type = get_shadow_addr_type(info, guest_pa);
773 pte_cursor = &(pt[i]);
775 if (host_page_type == HOST_REGION_INVALID) {
776 // Currently we don't support this, but in theory we could
777 PrintError("Invalid Host Memory Type\n");
779 } else if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) {
780 addr_t shadow_pa = get_shadow_addr(info, guest_pa);
783 pte_cursor->page_base_addr = PT32_BASE_ADDR(shadow_pa);
784 pte_cursor->present = 1;
785 pte_cursor->writable = large_shadow_pde->writable;
786 pte_cursor->user_page = large_shadow_pde->user_page;
787 pte_cursor->write_through = 0;
788 pte_cursor->cache_disable = 0;
789 pte_cursor->global_page = 0;
792 PrintError("Unsupported Host Memory Type\n");
800 static int handle_large_pagefault32(struct guest_info * info,
801 pde32_t * guest_pde, pde32_t * shadow_pde,
802 addr_t fault_addr, pf_error_t error_code ) {
803 struct shadow_region * mem_reg;
804 pde32_4MB_t * large_guest_pde = (pde32_4MB_t *)guest_pde;
805 pde32_4MB_t * large_shadow_pde = (pde32_4MB_t *)shadow_pde;
806 host_region_type_t host_page_type;
807 addr_t guest_start_addr = PDE32_4MB_T_ADDR(*large_guest_pde);
808 // addr_t guest_end_addr = guest_start_addr + PAGE_SIZE_4MB; // start address + 4MB
811 // Check that the Guest PDE entry points to valid memory
812 // else Machine Check the guest
813 PrintDebug("Large Page: Page Base Addr=%x\n", guest_start_addr);
815 host_page_type = get_shadow_addr_type(info, guest_start_addr);
817 if (host_page_type == HOST_REGION_INVALID) {
818 PrintError("Invalid guest address in large page (0x%x)\n", guest_start_addr);
819 v3_raise_exception(info, MC_EXCEPTION);
825 if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) {
827 addr_t host_start_addr = 0;
828 addr_t region_end_addr = 0;
830 // Check for a large enough region in host memory
831 mem_reg = get_shadow_region_by_addr(&(info->mem_map), guest_start_addr);
832 PrintDebug("Host region: host_addr=%x (guest_start=%x, end=%x)\n",
833 mem_reg->host_addr, mem_reg->guest_start, mem_reg->guest_end);
834 host_start_addr = mem_reg->host_addr + (guest_start_addr - mem_reg->guest_start);
835 region_end_addr = mem_reg->host_addr + (mem_reg->guest_end - mem_reg->guest_start);
837 PrintDebug("Host Start Addr=%x; Region End Addr=%x\n", host_start_addr, region_end_addr);
841 if (large_guest_pde->dirty == 1) { // dirty
842 large_shadow_pde->writable = guest_pde->writable;
843 } else if (error_code.write == 1) { // not dirty, access is write
844 large_shadow_pde->writable = guest_pde->writable;
845 large_guest_pde->dirty = 1;
846 } else { // not dirty, access is read
847 large_shadow_pde->writable = 0;
851 // Check if the region is at least an additional 4MB
855 if ((PD32_4MB_PAGE_OFFSET(host_start_addr) == 0) &&
856 (region_end_addr >= host_start_addr + PAGE_SIZE_4MB)) { // if 4MB boundary
857 large_shadow_pde->page_base_addr = PD32_4MB_BASE_ADDR(host_start_addr);
858 } else { // else generate 4k pages
859 pte32_t * shadow_pt = NULL;
860 PrintDebug("Handling non aligned large page\n");
862 shadow_pde->large_page = 0;
864 shadow_pt = create_new_shadow_pt32();
866 if (create_pd32_nonaligned_4MB_page(info, shadow_pt, guest_start_addr, large_shadow_pde) == -1) {
867 PrintError("Non Aligned Large Page Error\n");
873 #ifdef DEBUG_SHADOW_PAGING
874 PrintDebug("non-aligned Shadow PT\n");
875 PrintPT32(PT32_PAGE_ADDR(fault_addr), shadow_pt);
877 shadow_pde->pt_base_addr = PD32_BASE_ADDR(shadow_pt);
881 // Handle hooked pages as well as other special pages
882 if (handle_special_page_fault(info, fault_addr, guest_start_addr, error_code) == -1) {
883 PrintError("Special Page Fault handler returned error for address: %x\n", fault_addr);