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>
27 #include <palacios/vmm_ctrl_regs.h>
29 #include <palacios/vmm_hashtable.h>
31 #ifndef DEBUG_SHADOW_PAGING
33 #define PrintDebug(fmt, args...)
44 struct list_head link;
50 struct list_head link;
54 struct shadow_page_data {
58 struct list_head backptrs;
59 struct list_head guest_tables;
65 //DEFINE_HASHTABLE_INSERT(add_cr3_to_cache, addr_t, struct hashtable *);
66 //DEFINE_HASHTABLE_SEARCH(find_cr3_in_cache, addr_t, struct hashtable *);
67 //DEFINE_HASHTABLE_REMOVE(del_cr3_from_cache, addr_t, struct hashtable *, 0);
70 DEFINE_HASHTABLE_INSERT(add_pte_map, addr_t, addr_t);
71 DEFINE_HASHTABLE_SEARCH(find_pte_map, addr_t, addr_t);
72 //DEFINE_HASHTABLE_REMOVE(del_pte_map, addr_t, addr_t, 0);
76 static uint_t pte_hash_fn(addr_t key) {
77 return hash_long(key, 32);
80 static int pte_equals(addr_t key1, addr_t key2) {
81 return (key1 == key2);
84 static uint_t cr3_hash_fn(addr_t key) {
85 return hash_long(key, 32);
88 static int cr3_equals(addr_t key1, addr_t key2) {
89 return (key1 == key2);
94 static int activate_shadow_pt_32(struct guest_info * info);
95 static int activate_shadow_pt_32pae(struct guest_info * info);
96 static int activate_shadow_pt_64(struct guest_info * info);
99 static int handle_shadow_pagefault_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code);
100 static int handle_shadow_pagefault_32pae(struct guest_info * info, addr_t fault_addr, pf_error_t error_code);
101 static int handle_shadow_pagefault_64(struct guest_info * info, addr_t fault_addr, pf_error_t error_code);
104 static int cache_page_tables_32(struct guest_info * info, addr_t pde);
105 static int cache_page_tables_64(struct guest_info * info, addr_t pde);
107 int v3_init_shadow_page_state(struct guest_info * info) {
108 struct shadow_page_state * state = &(info->shdw_pg_state);
110 state->guest_cr3 = 0;
111 state->guest_cr0 = 0;
113 state->cr3_cache = create_hashtable(0, &cr3_hash_fn, &cr3_equals);
115 state->cached_cr3 = 0;
116 state->cached_ptes = NULL;
125 int v3_cache_page_tables(struct guest_info * info, addr_t cr3) {
126 switch(v3_get_cpu_mode(info)) {
128 return cache_page_tables_32(info, CR3_TO_PDE32_PA(cr3));
134 static int cache_page_tables_32(struct guest_info * info, addr_t pde) {
135 struct shadow_page_state * state = &(info->shdw_pg_state);
136 addr_t pde_host_addr;
138 struct hashtable * pte_cache = NULL;
141 if (pde == state->cached_cr3) {
145 if (state->cached_ptes != NULL) {
146 hashtable_destroy(state->cached_ptes, 0, 0);
147 state->cached_ptes = NULL;
150 state->cached_cr3 = pde;
152 pte_cache = create_hashtable(0, &pte_hash_fn, &pte_equals);
153 state->cached_ptes = pte_cache;
155 if (guest_pa_to_host_va(info, pde, &pde_host_addr) == -1) {
156 PrintError("Could not lookup host address of guest PDE\n");
160 tmp_pde = (pde32_t *)pde_host_addr;
162 add_pte_map(pte_cache, pde, pde_host_addr);
165 for (i = 0; i < MAX_PDE32_ENTRIES; i++) {
166 if ((tmp_pde[i].present) && (tmp_pde[i].large_page == 0)) {
167 addr_t pte_host_addr;
169 if (guest_pa_to_host_va(info, (addr_t)(BASE_TO_PAGE_ADDR(tmp_pde[i].pt_base_addr)), &pte_host_addr) == -1) {
170 PrintError("Could not lookup host address of guest PDE\n");
174 add_pte_map(pte_cache, (addr_t)(BASE_TO_PAGE_ADDR(tmp_pde[i].pt_base_addr)), pte_host_addr);
183 static int cache_page_tables_64(struct guest_info * info, addr_t pde) {
188 int v3_replace_shdw_page32(struct guest_info * info, addr_t location, pte32_t * new_page, pte32_t * old_page) {
189 pde32_t * shadow_pd = (pde32_t *)CR3_TO_PDE32_VA(info->ctrl_regs.cr3);
190 pde32_t * shadow_pde = (pde32_t *)&(shadow_pd[PDE32_INDEX(location)]);
192 if (shadow_pde->large_page == 0) {
193 pte32_t * shadow_pt = (pte32_t *)(addr_t)BASE_TO_PAGE_ADDR(shadow_pde->pt_base_addr);
194 pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(location)]);
196 //if (shadow_pte->present == 1) {
197 *(uint_t *)old_page = *(uint_t *)shadow_pte;
200 *(uint_t *)shadow_pte = *(uint_t *)new_page;
203 // currently unhandled
204 PrintError("Replacing large shadow pages not implemented\n");
215 // We assume that shdw_pg_state.guest_cr3 is pointing to the page tables we want to activate
216 // We also assume that the CPU mode has not changed during this page table transition
217 static int activate_shadow_pt_32(struct guest_info * info) {
218 struct cr3_32 * shadow_cr3 = (struct cr3_32 *)&(info->ctrl_regs.cr3);
219 struct cr3_32 * guest_cr3 = (struct cr3_32 *)&(info->shdw_pg_state.guest_cr3);
222 // Check if shadow page tables are in the cache
223 cached = cache_page_tables_32(info, CR3_TO_PDE32_PA(*(addr_t *)guest_cr3));
226 PrintError("CR3 Cache failed\n");
228 } else if (cached == 0) {
231 PrintDebug("New CR3 is different - flushing shadow page table %p\n", shadow_cr3 );
232 delete_page_tables_32(CR3_TO_PDE32_VA(*(uint_t*)shadow_cr3));
234 shadow_pt = v3_create_new_shadow_pt();
236 shadow_cr3->pdt_base_addr = (addr_t)V3_PAddr((void *)(addr_t)PAGE_BASE_ADDR(shadow_pt));
237 PrintDebug( "Created new shadow page table %p\n", (void *)(addr_t)shadow_cr3->pdt_base_addr );
239 PrintDebug("Reusing cached shadow Page table\n");
242 shadow_cr3->pwt = guest_cr3->pwt;
243 shadow_cr3->pcd = guest_cr3->pcd;
248 static int activate_shadow_pt_32pae(struct guest_info * info) {
249 PrintError("Activating 32 bit PAE page tables not implemented\n");
253 static int activate_shadow_pt_64_cb(page_type_t type, addr_t vaddr, addr_t page_ptr, addr_t page_pa, void * private_data) {
254 PrintDebug("CB: Page: %p->%p (host_ptr=%p), Type: %s\n", (void *)vaddr, (void *)page_pa, (void *)page_ptr, v3_page_type_to_str(type));
259 static int activate_shadow_pt_64(struct guest_info * info) {
260 // struct cr3_64 * shadow_cr3 = (struct cr3_64 *)&(info->ctrl_regs.cr3);
261 struct cr3_64 * guest_cr3 = (struct cr3_64 *)&(info->shdw_pg_state.guest_cr3);
264 v3_walk_guest_pt_64(info, info->shdw_pg_state.guest_cr3, activate_shadow_pt_64_cb, NULL);
271 // Check if shadow page tables are in the cache
272 cached = cache_page_tables_64(info, CR3_TO_PDE32_PA(*(addr_t *)guest_cr3));
275 PrintError("CR3 Cache failed\n");
277 } else if (cached == 0) {
280 PrintDebug("New CR3 is different - flushing shadow page table %p\n", shadow_cr3 );
281 delete_page_tables_32(CR3_TO_PDE32_VA(*(uint_t*)shadow_cr3));
283 shadow_pt = v3_create_new_shadow_pt();
285 shadow_cr3->pml4t_base_addr = (addr_t)V3_PAddr((void *)(addr_t)PAGE_BASE_ADDR(shadow_pt));
286 PrintDebug( "Created new shadow page table %p\n", (void *)(addr_t)shadow_cr3->pml4t_base_addr );
288 PrintDebug("Reusing cached shadow Page table\n");
291 shadow_cr3->pwt = guest_cr3->pwt;
292 shadow_cr3->pcd = guest_cr3->pcd;
299 // Reads the guest CR3 register
300 // creates new shadow page tables
301 // updates the shadow CR3 register to point to the new pts
302 int v3_activate_shadow_pt(struct guest_info * info) {
303 switch (info->cpu_mode) {
306 return activate_shadow_pt_32(info);
308 return activate_shadow_pt_32pae(info);
312 return activate_shadow_pt_64(info);
314 PrintError("Invalid CPU mode: %d\n", info->cpu_mode);
322 int v3_activate_passthrough_pt(struct guest_info * info) {
323 // For now... But we need to change this....
324 // As soon as shadow paging becomes active the passthrough tables are hosed
325 // So this will cause chaos if it is called at that time
327 info->ctrl_regs.cr3 = *(addr_t*)&(info->direct_map_pt);
328 //PrintError("Activate Passthrough Page tables not implemented\n");
334 int v3_handle_shadow_pagefault(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
336 if (info->mem_mode == PHYSICAL_MEM) {
337 // If paging is not turned on we need to handle the special cases
339 #ifdef DEBUG_SHADOW_PAGING
340 PrintHostPageTree(info->cpu_mode, fault_addr, info->ctrl_regs.cr3);
341 PrintGuestPageTree(info, fault_addr, info->shdw_pg_state.guest_cr3);
344 return handle_special_page_fault(info, fault_addr, fault_addr, error_code);
345 } else if (info->mem_mode == VIRTUAL_MEM) {
347 switch (info->cpu_mode) {
349 return handle_shadow_pagefault_32(info, fault_addr, error_code);
352 return handle_shadow_pagefault_32pae(info, fault_addr, error_code);
354 return handle_shadow_pagefault_64(info, fault_addr, error_code);
357 PrintError("Unhandled CPU Mode\n");
361 PrintError("Invalid Memory mode\n");
366 addr_t v3_create_new_shadow_pt() {
369 host_pde = V3_VAddr(V3_AllocPages(1));
370 memset(host_pde, 0, PAGE_SIZE);
372 return (addr_t)host_pde;
376 static void inject_guest_pf(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
377 if (info->enable_profiler) {
378 info->profiler.guest_pf_cnt++;
381 info->ctrl_regs.cr2 = fault_addr;
382 v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code);
386 static int is_guest_pf(pt_access_status_t guest_access, pt_access_status_t shadow_access) {
387 /* basically the reasoning is that there can be multiple reasons for a page fault:
388 If there is a permissions failure for a page present in the guest _BUT_
389 the reason for the fault was that the page is not present in the shadow,
390 _THEN_ we have to map the shadow page in and reexecute, this will generate
391 a permissions fault which is _THEN_ valid to send to the guest
392 _UNLESS_ both the guest and shadow have marked the page as not present
396 if (guest_access != PT_ACCESS_OK) {
397 // Guest Access Error
399 if ((shadow_access != PT_ACCESS_NOT_PRESENT) &&
400 (guest_access != PT_ACCESS_NOT_PRESENT)) {
401 // aka (guest permission error)
405 if ((shadow_access == PT_ACCESS_NOT_PRESENT) &&
406 (guest_access == PT_ACCESS_NOT_PRESENT)) {
407 // Page tables completely blank, handle guest first
411 // Otherwise we'll handle the guest fault later...?
423 * * 64 bit Page table fault handlers
428 static int handle_shadow_pagefault_64(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
429 pt_access_status_t guest_access;
430 pt_access_status_t shadow_access;
432 PrintDebug("64 bit shadow page fault\n");
434 ret = v3_check_guest_pt_32(info, info->shdw_pg_state.guest_cr3, fault_addr, error_code, &guest_access);
436 PrintDebug("Guest Access Check: %d (access=%d)\n", ret, guest_access);
438 ret = v3_check_host_pt_32(info->ctrl_regs.cr3, fault_addr, error_code, &shadow_access);
440 PrintDebug("Shadow Access Check: %d (access=%d)\n", ret, shadow_access);
443 PrintError("64 bit shadow paging not implemented\n");
451 * * 32 bit PAE Page table fault handlers
456 static int handle_shadow_pagefault_32pae(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
457 PrintError("32 bit PAE shadow paging not implemented\n");
470 * * 32 bit Page table fault handlers
474 static int handle_large_pagefault_32(struct guest_info * info,
475 addr_t fault_addr, pf_error_t error_code,
476 pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde);
478 static int handle_shadow_pte32_fault(struct guest_info * info,
480 pf_error_t error_code,
485 static int handle_shadow_pagefault_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
486 pde32_t * guest_pd = NULL;
487 pde32_t * shadow_pd = CR3_TO_PDE32_VA(info->ctrl_regs.cr3);
488 addr_t guest_cr3 = CR3_TO_PDE32_PA(info->shdw_pg_state.guest_cr3);
489 pt_access_status_t guest_pde_access;
490 pt_access_status_t shadow_pde_access;
491 pde32_t * guest_pde = NULL;
492 pde32_t * shadow_pde = (pde32_t *)&(shadow_pd[PDE32_INDEX(fault_addr)]);
494 PrintDebug("Shadow page fault handler: %p\n", (void*) fault_addr );
496 if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pd) == -1) {
497 PrintError("Invalid Guest PDE Address: 0x%p\n", (void *)guest_cr3);
501 guest_pde = (pde32_t *)&(guest_pd[PDE32_INDEX(fault_addr)]);
504 // Check the guest page permissions
505 guest_pde_access = v3_can_access_pde32(guest_pd, fault_addr, error_code);
507 // Check the shadow page permissions
508 shadow_pde_access = v3_can_access_pde32(shadow_pd, fault_addr, error_code);
510 /* Was the page fault caused by the Guest's page tables? */
511 if (is_guest_pf(guest_pde_access, shadow_pde_access) == 1) {
512 PrintDebug("Injecting PDE pf to guest: (guest access error=%d) (pf error code=%d)\n",
513 *(uint_t *)&guest_pde_access, *(uint_t *)&error_code);
514 inject_guest_pf(info, fault_addr, error_code);
519 if (shadow_pde_access == PT_ACCESS_NOT_PRESENT)
521 pte32_t * shadow_pt = (pte32_t *)v3_create_new_shadow_pt();
523 shadow_pde->present = 1;
524 shadow_pde->user_page = guest_pde->user_page;
525 // shadow_pde->large_page = guest_pde->large_page;
526 shadow_pde->large_page = 0;
529 // VMM Specific options
530 shadow_pde->write_through = 0;
531 shadow_pde->cache_disable = 0;
532 shadow_pde->global_page = 0;
535 guest_pde->accessed = 1;
537 shadow_pde->pt_base_addr = PAGE_BASE_ADDR((addr_t)V3_PAddr(shadow_pt));
539 if (guest_pde->large_page == 0) {
540 pte32_t * guest_pt = NULL;
541 shadow_pde->writable = guest_pde->writable;
543 if (guest_pa_to_host_va(info, BASE_TO_PAGE_ADDR(guest_pde->pt_base_addr), (addr_t*)&guest_pt) == -1) {
544 // Machine check the guest
545 PrintDebug("Invalid Guest PTE Address: 0x%p\n", (void *)BASE_TO_PAGE_ADDR(guest_pde->pt_base_addr));
546 v3_raise_exception(info, MC_EXCEPTION);
550 if (handle_shadow_pte32_fault(info, fault_addr, error_code, shadow_pt, guest_pt) == -1) {
551 PrintError("Error handling Page fault caused by PTE\n");
555 // ?? What if guest pde is dirty a this point?
556 ((pde32_4MB_t *)guest_pde)->dirty = 0;
557 shadow_pde->writable = 0;
560 else if (shadow_pde_access == PT_ACCESS_OK)
565 pte32_t * shadow_pt = (pte32_t *)V3_VAddr( (void*)(addr_t) BASE_TO_PAGE_ADDR(shadow_pde->pt_base_addr) );
567 if (guest_pde->large_page == 0) {
568 pte32_t * guest_pt = NULL;
570 if (guest_pa_to_host_va(info, BASE_TO_PAGE_ADDR(guest_pde->pt_base_addr), (addr_t*)&guest_pt) == -1) {
571 // Machine check the guest
572 PrintDebug("Invalid Guest PTE Address: 0x%p\n", (void *)BASE_TO_PAGE_ADDR(guest_pde->pt_base_addr));
573 v3_raise_exception(info, MC_EXCEPTION);
577 if (handle_shadow_pte32_fault(info, fault_addr, error_code, shadow_pt, guest_pt) == -1) {
578 PrintError("Error handling Page fault caused by PTE\n");
581 } else if (guest_pde->large_page == 1) {
582 if (handle_large_pagefault_32(info, fault_addr, error_code, shadow_pt, (pde32_4MB_t *)guest_pde) == -1) {
583 PrintError("Error handling large pagefault\n");
588 else if ((shadow_pde_access == PT_ACCESS_WRITE_ERROR) &&
589 (guest_pde->large_page == 1) &&
590 (((pde32_4MB_t *)guest_pde)->dirty == 0))
593 // Page Directory Entry marked read-only
594 // Its a large page and we need to update the dirty bit in the guest
597 PrintDebug("Large page write error... Setting dirty bit and returning\n");
598 ((pde32_4MB_t *)guest_pde)->dirty = 1;
599 shadow_pde->writable = guest_pde->writable;
603 else if (shadow_pde_access == PT_ACCESS_USER_ERROR)
606 // Page Directory Entry marked non-user
608 PrintDebug("Shadow Paging User access error (shadow_pde_access=0x%x, guest_pde_access=0x%x)\n",
609 shadow_pde_access, guest_pde_access);
610 inject_guest_pf(info, fault_addr, error_code);
615 // inject page fault in guest
616 inject_guest_pf(info, fault_addr, error_code);
617 PrintDebug("Unknown Error occurred (shadow_pde_access=%d)\n", shadow_pde_access);
618 PrintDebug("Manual Says to inject page fault into guest\n");
619 #ifdef DEBUG_SHADOW_PAGING
620 PrintDebug("Guest PDE: (access=%d)\n\t", guest_pde_access);
621 PrintPTEntry(PAGE_PD32, fault_addr, guest_pde);
622 PrintDebug("Shadow PDE: (access=%d)\n\t", shadow_pde_access);
623 PrintPTEntry(PAGE_PD32, fault_addr, shadow_pde);
629 PrintDebug("Returning end of PDE function (rip=%p)\n", (void *)(addr_t)(info->rip));
635 /* The guest status checks have already been done,
636 * only special case shadow checks remain
638 static int handle_large_pagefault_32(struct guest_info * info,
639 addr_t fault_addr, pf_error_t error_code,
640 pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde)
642 pt_access_status_t shadow_pte_access = v3_can_access_pte32(shadow_pt, fault_addr, error_code);
643 pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(fault_addr)]);
644 addr_t guest_fault_pa = BASE_TO_PAGE_ADDR_4MB(large_guest_pde->page_base_addr) + PAGE_OFFSET_4MB(fault_addr);
646 struct v3_shadow_region * shdw_reg = v3_get_shadow_region(info, guest_fault_pa);
649 if ((shdw_reg == NULL) ||
650 (shdw_reg->host_type == SHDW_REGION_INVALID)) {
651 // Inject a machine check in the guest
652 PrintDebug("Invalid Guest Address in page table (0x%p)\n", (void *)guest_fault_pa);
653 v3_raise_exception(info, MC_EXCEPTION);
657 if (shadow_pte_access == PT_ACCESS_OK) {
658 // Inconsistent state...
659 // Guest Re-Entry will flush tables and everything should now workd
660 PrintDebug("Inconsistent state... Guest re-entry should flush tlb\n");
665 if (shadow_pte_access == PT_ACCESS_NOT_PRESENT) {
666 // Get the guest physical address of the fault
668 if ((shdw_reg->host_type == SHDW_REGION_ALLOCATED) ||
669 (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK)) {
670 struct shadow_page_state * state = &(info->shdw_pg_state);
671 addr_t shadow_pa = v3_get_shadow_addr(shdw_reg, guest_fault_pa);
673 shadow_pte->page_base_addr = PAGE_BASE_ADDR(shadow_pa);
675 shadow_pte->present = 1;
677 /* We are assuming that the PDE entry has precedence
678 * so the Shadow PDE will mirror the guest PDE settings,
679 * and we don't have to worry about them here
682 shadow_pte->user_page = 1;
684 if (find_pte_map(state->cached_ptes, PAGE_ADDR(guest_fault_pa)) != NULL) {
685 // Check if the entry is a page table...
686 PrintDebug("Marking page as Guest Page Table (large page)\n");
687 shadow_pte->vmm_info = PT32_GUEST_PT;
688 shadow_pte->writable = 0;
689 } else if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
690 shadow_pte->writable = 0;
692 shadow_pte->writable = 1;
695 //set according to VMM policy
696 shadow_pte->write_through = 0;
697 shadow_pte->cache_disable = 0;
698 shadow_pte->global_page = 0;
702 // Handle hooked pages as well as other special pages
703 // if (handle_special_page_fault(info, fault_addr, guest_fault_pa, error_code) == -1) {
705 if (v3_handle_mem_full_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
706 PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
710 } else if (shadow_pte_access == PT_ACCESS_WRITE_ERROR) {
712 if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
714 if (v3_handle_mem_wr_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
715 PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
718 } else if (shadow_pte->vmm_info == PT32_GUEST_PT) {
719 struct shadow_page_state * state = &(info->shdw_pg_state);
720 PrintDebug("Write operation on Guest PAge Table Page (large page)\n");
721 state->cached_cr3 = 0;
722 shadow_pte->writable = 1;
726 PrintError("Error in large page fault handler...\n");
727 PrintError("This case should have been handled at the top level handler\n");
731 PrintDebug("Returning from large page fault handler\n");
739 * We assume the the guest pte pointer has already been translated to a host virtual address
741 static int handle_shadow_pte32_fault(struct guest_info * info,
743 pf_error_t error_code,
745 pte32_t * guest_pt) {
747 pt_access_status_t guest_pte_access;
748 pt_access_status_t shadow_pte_access;
749 pte32_t * guest_pte = (pte32_t *)&(guest_pt[PTE32_INDEX(fault_addr)]);;
750 pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(fault_addr)]);
751 addr_t guest_pa = BASE_TO_PAGE_ADDR((addr_t)(guest_pte->page_base_addr)) + PAGE_OFFSET(fault_addr);
753 struct v3_shadow_region * shdw_reg = v3_get_shadow_region(info, guest_pa);
755 if ((shdw_reg == NULL) ||
756 (shdw_reg->host_type == SHDW_REGION_INVALID)) {
757 // Inject a machine check in the guest
758 PrintDebug("Invalid Guest Address in page table (0x%p)\n", (void *)guest_pa);
759 v3_raise_exception(info, MC_EXCEPTION);
763 // Check the guest page permissions
764 guest_pte_access = v3_can_access_pte32(guest_pt, fault_addr, error_code);
766 // Check the shadow page permissions
767 shadow_pte_access = v3_can_access_pte32(shadow_pt, fault_addr, error_code);
769 #ifdef DEBUG_SHADOW_PAGING
770 PrintDebug("Guest PTE: (access=%d)\n\t", guest_pte_access);
771 PrintPTEntry(PAGE_PT32, fault_addr, guest_pte);
772 PrintDebug("Shadow PTE: (access=%d)\n\t", shadow_pte_access);
773 PrintPTEntry(PAGE_PT32, fault_addr, shadow_pte);
776 /* Was the page fault caused by the Guest's page tables? */
777 if (is_guest_pf(guest_pte_access, shadow_pte_access) == 1) {
778 PrintDebug("Access error injecting pf to guest (guest access error=%d) (pf error code=%d)\n",
779 guest_pte_access, *(uint_t*)&error_code);
780 inject_guest_pf(info, fault_addr, error_code);
785 if (shadow_pte_access == PT_ACCESS_OK) {
786 // Inconsistent state...
787 // Guest Re-Entry will flush page tables and everything should now work
788 PrintDebug("Inconsistent state... Guest re-entry should flush tlb\n");
793 if (shadow_pte_access == PT_ACCESS_NOT_PRESENT) {
794 // Page Table Entry Not Present
795 PrintDebug("guest_pa =%p\n", (void *)guest_pa);
797 if ((shdw_reg->host_type == SHDW_REGION_ALLOCATED) ||
798 (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK)) {
799 struct shadow_page_state * state = &(info->shdw_pg_state);
800 addr_t shadow_pa = v3_get_shadow_addr(shdw_reg, guest_pa);
802 shadow_pte->page_base_addr = PAGE_BASE_ADDR(shadow_pa);
804 shadow_pte->present = guest_pte->present;
805 shadow_pte->user_page = guest_pte->user_page;
807 //set according to VMM policy
808 shadow_pte->write_through = 0;
809 shadow_pte->cache_disable = 0;
810 shadow_pte->global_page = 0;
813 guest_pte->accessed = 1;
815 if (find_pte_map(state->cached_ptes, PAGE_ADDR(guest_pa)) != NULL) {
816 // Check if the entry is a page table...
817 PrintDebug("Marking page as Guest Page Table %d\n", shadow_pte->writable);
818 shadow_pte->vmm_info = PT32_GUEST_PT;
821 if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
822 shadow_pte->writable = 0;
823 } else if (guest_pte->dirty == 1) {
824 shadow_pte->writable = guest_pte->writable;
825 } else if ((guest_pte->dirty == 0) && (error_code.write == 1)) {
826 shadow_pte->writable = guest_pte->writable;
827 guest_pte->dirty = 1;
829 if (shadow_pte->vmm_info == PT32_GUEST_PT) {
830 // Well that was quick...
831 struct shadow_page_state * state = &(info->shdw_pg_state);
832 PrintDebug("Immediate Write operation on Guest PAge Table Page\n");
833 state->cached_cr3 = 0;
836 } else if ((guest_pte->dirty == 0) && (error_code.write == 0)) { // was =
837 shadow_pte->writable = 0;
841 // Page fault handled by hook functions
843 if (v3_handle_mem_full_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
844 PrintError("Special Page fault handler returned error for address: %p\n", (void *)fault_addr);
849 } else if ((shadow_pte_access == PT_ACCESS_WRITE_ERROR) &&
850 (guest_pte->dirty == 0)) {
852 } else if (shadow_pte_access == PT_ACCESS_WRITE_ERROR) {
853 guest_pte->dirty = 1;
855 if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
856 if (v3_handle_mem_wr_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
857 PrintError("Special Page fault handler returned error for address: %p\n", (void *)fault_addr);
861 PrintDebug("Shadow PTE Write Error\n");
862 shadow_pte->writable = guest_pte->writable;
865 if (shadow_pte->vmm_info == PT32_GUEST_PT) {
866 struct shadow_page_state * state = &(info->shdw_pg_state);
867 PrintDebug("Write operation on Guest PAge Table Page\n");
868 state->cached_cr3 = 0;
874 // Inject page fault into the guest
875 inject_guest_pf(info, fault_addr, error_code);
876 PrintError("PTE Page fault fell through... Not sure if this should ever happen\n");
877 PrintError("Manual Says to inject page fault into guest\n");
881 PrintDebug("Returning end of function\n");
890 /* Currently Does not work with Segmentation!!! */
891 int v3_handle_shadow_invlpg(struct guest_info * info)
893 if (info->mem_mode != VIRTUAL_MEM) {
894 // Paging must be turned on...
895 // should handle with some sort of fault I think
896 PrintError("ERROR: INVLPG called in non paged mode\n");
901 if (info->cpu_mode != PROTECTED) {
902 PrintError("Unsupported CPU mode (mode=%s)\n", v3_cpu_mode_to_str(info->cpu_mode));
909 int ret = read_guest_va_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
911 PrintError("Could not read instruction 0x%p (ret=%d)\n", (void *)(addr_t)(info->rip), ret);
916 /* Can INVLPG work with Segments?? */
917 while (is_prefix_byte(instr[index])) {
922 if( (instr[index + 0] != (uchar_t) 0x0f) ||
923 (instr[index + 1] != (uchar_t) 0x01) ) {
924 PrintError("invalid Instruction Opcode\n");
925 PrintTraceMemDump(instr, 15);
929 addr_t first_operand;
930 addr_t second_operand;
931 addr_t guest_cr3 = CR3_TO_PDE32_PA(info->shdw_pg_state.guest_cr3);
933 pde32_t * guest_pd = NULL;
935 if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pd) == -1) {
936 PrintError("Invalid Guest PDE Address: 0x%p\n", (void *)guest_cr3);
942 v3_operand_type_t addr_type = decode_operands32(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG32);
944 if (addr_type != MEM_OPERAND) {
945 PrintError("Invalid Operand type\n");
949 pde32_t * shadow_pd = (pde32_t *)CR3_TO_PDE32_VA(info->ctrl_regs.cr3);
950 pde32_t * shadow_pde = (pde32_t *)&shadow_pd[PDE32_INDEX(first_operand)];
953 //PrintDebug("PDE Index=%d\n", PDE32_INDEX(first_operand));
954 //PrintDebug("FirstOperand = %x\n", first_operand);
956 PrintDebug("Invalidating page for %p\n", (void *)first_operand);
958 guest_pde = (pde32_t *)&(guest_pd[PDE32_INDEX(first_operand)]);
960 if (guest_pde->large_page == 1) {
961 shadow_pde->present = 0;
962 PrintDebug("Invalidating Large Page\n");
964 if (shadow_pde->present == 1) {
965 pte32_t * shadow_pt = (pte32_t *)(addr_t)BASE_TO_PAGE_ADDR(shadow_pde->pt_base_addr);
966 pte32_t * shadow_pte = (pte32_t *) V3_VAddr( (void*) &shadow_pt[PTE32_INDEX(first_operand)] );
968 #ifdef DEBUG_SHADOW_PAGING
969 PrintDebug("Setting not present\n");
970 PrintPTEntry(PAGE_PT32, first_operand, shadow_pte);
973 shadow_pte->present = 0;