2 static int cache_page_tables_32(struct guest_info * info, addr_t pde) {
3 struct shadow_page_state * state = &(info->shdw_pg_state);
6 struct hashtable * pte_cache = NULL;
9 if (pde == state->cached_cr3) {
13 if (state->cached_ptes != NULL) {
14 hashtable_destroy(state->cached_ptes, 0, 0);
15 state->cached_ptes = NULL;
18 state->cached_cr3 = pde;
20 pte_cache = create_hashtable(0, &pte_hash_fn, &pte_equals);
21 state->cached_ptes = pte_cache;
23 if (guest_pa_to_host_va(info, pde, &pde_host_addr) == -1) {
24 PrintError("Could not lookup host address of guest PDE\n");
28 tmp_pde = (pde32_t *)pde_host_addr;
30 add_pte_map(pte_cache, pde, pde_host_addr);
33 for (i = 0; i < MAX_PDE32_ENTRIES; i++) {
34 if ((tmp_pde[i].present) && (tmp_pde[i].large_page == 0)) {
37 if (guest_pa_to_host_va(info, (addr_t)(BASE_TO_PAGE_ADDR(tmp_pde[i].pt_base_addr)), &pte_host_addr) == -1) {
38 PrintError("Could not lookup host address of guest PDE\n");
42 add_pte_map(pte_cache, (addr_t)(BASE_TO_PAGE_ADDR(tmp_pde[i].pt_base_addr)), pte_host_addr);
52 // We assume that shdw_pg_state.guest_cr3 is pointing to the page tables we want to activate
53 // We also assume that the CPU mode has not changed during this page table transition
54 static inline int activate_shadow_pt_32(struct guest_info * info) {
55 struct cr3_32 * shadow_cr3 = (struct cr3_32 *)&(info->ctrl_regs.cr3);
56 struct cr3_32 * guest_cr3 = (struct cr3_32 *)&(info->shdw_pg_state.guest_cr3);
59 // Check if shadow page tables are in the cache
60 cached = cache_page_tables_32(info, CR3_TO_PDE32_PA(*(addr_t *)guest_cr3));
63 PrintError("CR3 Cache failed\n");
65 } else if (cached == 0) {
68 shadow_pt = create_new_shadow_pt(info);
70 shadow_cr3->pdt_base_addr = (addr_t)V3_PAddr((void *)(addr_t)PAGE_BASE_ADDR(shadow_pt));
71 PrintDebug( "Created new shadow page table %p\n", (void *)BASE_TO_PAGE_ADDR(shadow_cr3->pdt_base_addr));
73 PrintDebug("Reusing cached shadow Page table\n");
76 shadow_cr3->pwt = guest_cr3->pwt;
77 shadow_cr3->pcd = guest_cr3->pcd;
85 * * 32 bit Page table fault handlers
89 static int handle_large_pagefault_32(struct guest_info * info,
90 addr_t fault_addr, pf_error_t error_code,
91 pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde);
93 static int handle_shadow_pte32_fault(struct guest_info * info,
95 pf_error_t error_code,
100 static inline int handle_shadow_pagefault_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
101 pde32_t * guest_pd = NULL;
102 pde32_t * shadow_pd = CR3_TO_PDE32_VA(info->ctrl_regs.cr3);
103 addr_t guest_cr3 = CR3_TO_PDE32_PA(info->shdw_pg_state.guest_cr3);
104 pt_access_status_t guest_pde_access;
105 pt_access_status_t shadow_pde_access;
106 pde32_t * guest_pde = NULL;
107 pde32_t * shadow_pde = (pde32_t *)&(shadow_pd[PDE32_INDEX(fault_addr)]);
109 PrintDebug("Shadow page fault handler: %p\n", (void*) fault_addr );
111 if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pd) == -1) {
112 PrintError("Invalid Guest PDE Address: 0x%p\n", (void *)guest_cr3);
116 guest_pde = (pde32_t *)&(guest_pd[PDE32_INDEX(fault_addr)]);
119 // Check the guest page permissions
120 guest_pde_access = v3_can_access_pde32(guest_pd, fault_addr, error_code);
122 // Check the shadow page permissions
123 shadow_pde_access = v3_can_access_pde32(shadow_pd, fault_addr, error_code);
125 /* Was the page fault caused by the Guest's page tables? */
126 if (is_guest_pf(guest_pde_access, shadow_pde_access) == 1) {
127 PrintDebug("Injecting PDE pf to guest: (guest access error=%d) (pf error code=%d)\n",
128 *(uint_t *)&guest_pde_access, *(uint_t *)&error_code);
129 inject_guest_pf(info, fault_addr, error_code);
134 if (shadow_pde_access == PT_ACCESS_NOT_PRESENT)
136 pte32_t * shadow_pt = (pte32_t *)create_new_shadow_pt(info);
138 shadow_pde->present = 1;
139 shadow_pde->user_page = guest_pde->user_page;
140 // shadow_pde->large_page = guest_pde->large_page;
141 shadow_pde->large_page = 0;
144 // VMM Specific options
145 shadow_pde->write_through = 0;
146 shadow_pde->cache_disable = 0;
147 shadow_pde->global_page = 0;
150 guest_pde->accessed = 1;
152 shadow_pde->pt_base_addr = PAGE_BASE_ADDR((addr_t)V3_PAddr(shadow_pt));
154 if (guest_pde->large_page == 0) {
155 pte32_t * guest_pt = NULL;
156 shadow_pde->writable = guest_pde->writable;
158 if (guest_pa_to_host_va(info, BASE_TO_PAGE_ADDR(guest_pde->pt_base_addr), (addr_t*)&guest_pt) == -1) {
159 // Machine check the guest
160 PrintDebug("Invalid Guest PTE Address: 0x%p\n", (void *)BASE_TO_PAGE_ADDR(guest_pde->pt_base_addr));
161 v3_raise_exception(info, MC_EXCEPTION);
165 if (handle_shadow_pte32_fault(info, fault_addr, error_code, shadow_pt, guest_pt) == -1) {
166 PrintError("Error handling Page fault caused by PTE\n");
170 // ?? What if guest pde is dirty a this point?
171 ((pde32_4MB_t *)guest_pde)->dirty = 0;
172 shadow_pde->writable = 0;
174 if (handle_large_pagefault_32(info, fault_addr, error_code, shadow_pt, (pde32_4MB_t *)guest_pde) == -1) {
175 PrintError("Error handling large pagefault\n");
181 else if (shadow_pde_access == PT_ACCESS_OK)
186 pte32_t * shadow_pt = (pte32_t *)V3_VAddr( (void*)(addr_t) BASE_TO_PAGE_ADDR(shadow_pde->pt_base_addr) );
188 if (guest_pde->large_page == 0) {
189 pte32_t * guest_pt = NULL;
191 if (guest_pa_to_host_va(info, BASE_TO_PAGE_ADDR(guest_pde->pt_base_addr), (addr_t*)&guest_pt) == -1) {
192 // Machine check the guest
193 PrintDebug("Invalid Guest PTE Address: 0x%p\n", (void *)BASE_TO_PAGE_ADDR(guest_pde->pt_base_addr));
194 v3_raise_exception(info, MC_EXCEPTION);
198 if (handle_shadow_pte32_fault(info, fault_addr, error_code, shadow_pt, guest_pt) == -1) {
199 PrintError("Error handling Page fault caused by PTE\n");
202 } else if (guest_pde->large_page == 1) {
203 if (handle_large_pagefault_32(info, fault_addr, error_code, shadow_pt, (pde32_4MB_t *)guest_pde) == -1) {
204 PrintError("Error handling large pagefault\n");
209 else if ((shadow_pde_access == PT_ACCESS_WRITE_ERROR) &&
210 (guest_pde->large_page == 1) &&
211 (((pde32_4MB_t *)guest_pde)->dirty == 0))
214 // Page Directory Entry marked read-only
215 // Its a large page and we need to update the dirty bit in the guest
218 PrintDebug("Large page write error... Setting dirty bit and returning\n");
219 ((pde32_4MB_t *)guest_pde)->dirty = 1;
220 shadow_pde->writable = guest_pde->writable;
224 else if (shadow_pde_access == PT_ACCESS_USER_ERROR)
227 // Page Directory Entry marked non-user
229 PrintDebug("Shadow Paging User access error (shadow_pde_access=0x%x, guest_pde_access=0x%x)\n",
230 shadow_pde_access, guest_pde_access);
231 inject_guest_pf(info, fault_addr, error_code);
236 // inject page fault in guest
237 inject_guest_pf(info, fault_addr, error_code);
238 PrintDebug("Unknown Error occurred (shadow_pde_access=%d)\n", shadow_pde_access);
239 PrintDebug("Manual Says to inject page fault into guest\n");
240 #ifdef DEBUG_SHADOW_PAGING
241 PrintDebug("Guest PDE: (access=%d)\n\t", guest_pde_access);
242 PrintPTEntry(PAGE_PD32, fault_addr, guest_pde);
243 PrintDebug("Shadow PDE: (access=%d)\n\t", shadow_pde_access);
244 PrintPTEntry(PAGE_PD32, fault_addr, shadow_pde);
250 PrintDebug("Returning end of PDE function (rip=%p)\n", (void *)(addr_t)(info->rip));
256 /* The guest status checks have already been done,
257 * only special case shadow checks remain
259 static int handle_large_pagefault_32(struct guest_info * info,
260 addr_t fault_addr, pf_error_t error_code,
261 pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde)
263 pt_access_status_t shadow_pte_access = v3_can_access_pte32(shadow_pt, fault_addr, error_code);
264 pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(fault_addr)]);
265 addr_t guest_fault_pa = BASE_TO_PAGE_ADDR_4MB(large_guest_pde->page_base_addr) + PAGE_OFFSET_4MB(fault_addr);
267 struct v3_shadow_region * shdw_reg = v3_get_shadow_region(info, guest_fault_pa);
270 if ((shdw_reg == NULL) ||
271 (shdw_reg->host_type == SHDW_REGION_INVALID)) {
272 // Inject a machine check in the guest
273 PrintDebug("Invalid Guest Address in page table (0x%p)\n", (void *)guest_fault_pa);
274 v3_raise_exception(info, MC_EXCEPTION);
278 if (shadow_pte_access == PT_ACCESS_OK) {
279 // Inconsistent state...
280 // Guest Re-Entry will flush tables and everything should now workd
281 PrintDebug("Inconsistent state... Guest re-entry should flush tlb\n");
286 if (shadow_pte_access == PT_ACCESS_NOT_PRESENT) {
287 // Get the guest physical address of the fault
289 if ((shdw_reg->host_type == SHDW_REGION_ALLOCATED) ||
290 (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK)) {
291 struct shadow_page_state * state = &(info->shdw_pg_state);
292 addr_t shadow_pa = v3_get_shadow_addr(shdw_reg, guest_fault_pa);
294 shadow_pte->page_base_addr = PAGE_BASE_ADDR(shadow_pa);
296 shadow_pte->present = 1;
298 /* We are assuming that the PDE entry has precedence
299 * so the Shadow PDE will mirror the guest PDE settings,
300 * and we don't have to worry about them here
303 shadow_pte->user_page = 1;
305 if (find_pte_map(state->cached_ptes, PAGE_ADDR(guest_fault_pa)) != NULL) {
306 // Check if the entry is a page table...
307 PrintDebug("Marking page as Guest Page Table (large page)\n");
308 shadow_pte->vmm_info = PT32_GUEST_PT;
309 shadow_pte->writable = 0;
310 } else if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
311 shadow_pte->writable = 0;
313 shadow_pte->writable = 1;
316 //set according to VMM policy
317 shadow_pte->write_through = 0;
318 shadow_pte->cache_disable = 0;
319 shadow_pte->global_page = 0;
323 // Handle hooked pages as well as other special pages
324 // if (handle_special_page_fault(info, fault_addr, guest_fault_pa, error_code) == -1) {
326 if (v3_handle_mem_full_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
327 PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
331 } else if (shadow_pte_access == PT_ACCESS_WRITE_ERROR) {
333 if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
335 if (v3_handle_mem_wr_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
336 PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
339 } else if (shadow_pte->vmm_info == PT32_GUEST_PT) {
340 struct shadow_page_state * state = &(info->shdw_pg_state);
341 PrintDebug("Write operation on Guest PAge Table Page (large page)\n");
342 state->cached_cr3 = 0;
343 shadow_pte->writable = 1;
347 PrintError("Error in large page fault handler...\n");
348 PrintError("This case should have been handled at the top level handler\n");
352 PrintDebug("Returning from large page fault handler\n");
360 * We assume the the guest pte pointer has already been translated to a host virtual address
362 static int handle_shadow_pte32_fault(struct guest_info * info,
364 pf_error_t error_code,
366 pte32_t * guest_pt) {
368 pt_access_status_t guest_pte_access;
369 pt_access_status_t shadow_pte_access;
370 pte32_t * guest_pte = (pte32_t *)&(guest_pt[PTE32_INDEX(fault_addr)]);;
371 pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(fault_addr)]);
372 addr_t guest_pa = BASE_TO_PAGE_ADDR((addr_t)(guest_pte->page_base_addr)) + PAGE_OFFSET(fault_addr);
374 struct v3_shadow_region * shdw_reg = v3_get_shadow_region(info, guest_pa);
376 if ((shdw_reg == NULL) ||
377 (shdw_reg->host_type == SHDW_REGION_INVALID)) {
378 // Inject a machine check in the guest
379 PrintDebug("Invalid Guest Address in page table (0x%p)\n", (void *)guest_pa);
380 v3_raise_exception(info, MC_EXCEPTION);
384 // Check the guest page permissions
385 guest_pte_access = v3_can_access_pte32(guest_pt, fault_addr, error_code);
387 // Check the shadow page permissions
388 shadow_pte_access = v3_can_access_pte32(shadow_pt, fault_addr, error_code);
390 #ifdef DEBUG_SHADOW_PAGING
391 PrintDebug("Guest PTE: (access=%d)\n\t", guest_pte_access);
392 PrintPTEntry(PAGE_PT32, fault_addr, guest_pte);
393 PrintDebug("Shadow PTE: (access=%d)\n\t", shadow_pte_access);
394 PrintPTEntry(PAGE_PT32, fault_addr, shadow_pte);
397 /* Was the page fault caused by the Guest's page tables? */
398 if (is_guest_pf(guest_pte_access, shadow_pte_access) == 1) {
399 PrintDebug("Access error injecting pf to guest (guest access error=%d) (pf error code=%d)\n",
400 guest_pte_access, *(uint_t*)&error_code);
401 inject_guest_pf(info, fault_addr, error_code);
406 if (shadow_pte_access == PT_ACCESS_OK) {
407 // Inconsistent state...
408 // Guest Re-Entry will flush page tables and everything should now work
409 PrintDebug("Inconsistent state... Guest re-entry should flush tlb\n");
414 if (shadow_pte_access == PT_ACCESS_NOT_PRESENT) {
415 // Page Table Entry Not Present
416 PrintDebug("guest_pa =%p\n", (void *)guest_pa);
418 if ((shdw_reg->host_type == SHDW_REGION_ALLOCATED) ||
419 (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK)) {
420 struct shadow_page_state * state = &(info->shdw_pg_state);
421 addr_t shadow_pa = v3_get_shadow_addr(shdw_reg, guest_pa);
423 shadow_pte->page_base_addr = PAGE_BASE_ADDR(shadow_pa);
425 shadow_pte->present = guest_pte->present;
426 shadow_pte->user_page = guest_pte->user_page;
428 //set according to VMM policy
429 shadow_pte->write_through = 0;
430 shadow_pte->cache_disable = 0;
431 shadow_pte->global_page = 0;
434 guest_pte->accessed = 1;
436 if (find_pte_map(state->cached_ptes, PAGE_ADDR(guest_pa)) != NULL) {
437 // Check if the entry is a page table...
438 PrintDebug("Marking page as Guest Page Table %d\n", shadow_pte->writable);
439 shadow_pte->vmm_info = PT32_GUEST_PT;
442 if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
443 shadow_pte->writable = 0;
444 } else if (guest_pte->dirty == 1) {
445 shadow_pte->writable = guest_pte->writable;
446 } else if ((guest_pte->dirty == 0) && (error_code.write == 1)) {
447 shadow_pte->writable = guest_pte->writable;
448 guest_pte->dirty = 1;
450 if (shadow_pte->vmm_info == PT32_GUEST_PT) {
451 // Well that was quick...
452 struct shadow_page_state * state = &(info->shdw_pg_state);
453 PrintDebug("Immediate Write operation on Guest PAge Table Page\n");
454 state->cached_cr3 = 0;
457 } else if ((guest_pte->dirty == 0) && (error_code.write == 0)) { // was =
458 shadow_pte->writable = 0;
462 // Page fault handled by hook functions
464 if (v3_handle_mem_full_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
465 PrintError("Special Page fault handler returned error for address: %p\n", (void *)fault_addr);
469 } else if (shadow_pte_access == PT_ACCESS_WRITE_ERROR) {
470 guest_pte->dirty = 1;
472 if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
473 if (v3_handle_mem_wr_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
474 PrintError("Special Page fault handler returned error for address: %p\n", (void *)fault_addr);
478 PrintDebug("Shadow PTE Write Error\n");
479 shadow_pte->writable = guest_pte->writable;
482 if (shadow_pte->vmm_info == PT32_GUEST_PT) {
483 struct shadow_page_state * state = &(info->shdw_pg_state);
484 PrintDebug("Write operation on Guest PAge Table Page\n");
485 state->cached_cr3 = 0;
491 // Inject page fault into the guest
492 inject_guest_pf(info, fault_addr, error_code);
493 PrintError("PTE Page fault fell through... Not sure if this should ever happen\n");
494 PrintError("Manual Says to inject page fault into guest\n");
498 PrintDebug("Returning end of function\n");
504 /* If we start to optimize we should look up the guest pages in the cache... */
505 static inline int handle_shadow_invlpg_32(struct guest_info * info, addr_t vaddr) {
506 pde32_t * shadow_pd = (pde32_t *)CR3_TO_PDE32_VA(info->ctrl_regs.cr3);
507 pde32_t * shadow_pde = (pde32_t *)&shadow_pd[PDE32_INDEX(vaddr)];
509 addr_t guest_cr3 = CR3_TO_PDE32_PA(info->shdw_pg_state.guest_cr3);
510 pde32_t * guest_pd = NULL;
513 if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pd) == -1) {
514 PrintError("Invalid Guest PDE Address: 0x%p\n", (void *)guest_cr3);
518 guest_pde = (pde32_t *)&(guest_pd[PDE32_INDEX(vaddr)]);
520 if (guest_pde->large_page == 1) {
521 shadow_pde->present = 0;
522 PrintDebug("Invalidating Large Page\n");
523 } else if (shadow_pde->present == 1) {
524 pte32_t * shadow_pt = (pte32_t *)(addr_t)BASE_TO_PAGE_ADDR_4KB(shadow_pde->pt_base_addr);
525 pte32_t * shadow_pte = (pte32_t *) V3_VAddr( (void*) &shadow_pt[PTE32_INDEX(vaddr)] );
527 PrintDebug("Setting not present\n");
529 shadow_pte->present = 0;