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".
23 static inline int activate_shadow_pt_32(struct guest_info * info) {
24 struct cr3_32 * shadow_cr3 = (struct cr3_32 *)&(info->ctrl_regs.cr3);
25 struct cr3_32 * guest_cr3 = (struct cr3_32 *)&(info->shdw_pg_state.guest_cr3);
26 struct shadow_page_data * shdw_page = create_new_shadow_pt(info);
28 shdw_page->cr3 = shdw_page->page_pa;
30 shadow_cr3->pdt_base_addr = PAGE_BASE_ADDR_4KB(shdw_page->page_pa);
31 PrintDebug( "Created new shadow page table %p\n", (void *)BASE_TO_PAGE_ADDR(shadow_cr3->pdt_base_addr));
33 shadow_cr3->pwt = guest_cr3->pwt;
34 shadow_cr3->pcd = guest_cr3->pcd;
45 * * 32 bit Page table fault handlers
49 static int handle_4MB_shadow_pagefault_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code,
50 pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde);
52 static int handle_pte_shadow_pagefault_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code,
53 pte32_t * shadow_pt, pte32_t * guest_pt);
56 static inline int handle_shadow_pagefault_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
57 pde32_t * guest_pd = NULL;
58 pde32_t * shadow_pd = CR3_TO_PDE32_VA(info->ctrl_regs.cr3);
59 addr_t guest_cr3 = CR3_TO_PDE32_PA(info->shdw_pg_state.guest_cr3);
60 pt_access_status_t guest_pde_access;
61 pt_access_status_t shadow_pde_access;
62 pde32_t * guest_pde = NULL;
63 pde32_t * shadow_pde = (pde32_t *)&(shadow_pd[PDE32_INDEX(fault_addr)]);
65 PrintDebug("Shadow page fault handler: %p\n", (void*) fault_addr );
66 PrintDebug("Handling PDE32 Fault\n");
68 if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pd) == -1) {
69 PrintError("Invalid Guest PDE Address: 0x%p\n", (void *)guest_cr3);
73 guest_pde = (pde32_t *)&(guest_pd[PDE32_INDEX(fault_addr)]);
76 // Check the guest page permissions
77 guest_pde_access = v3_can_access_pde32(guest_pd, fault_addr, error_code);
79 // Check the shadow page permissions
80 shadow_pde_access = v3_can_access_pde32(shadow_pd, fault_addr, error_code);
82 /* Was the page fault caused by the Guest's page tables? */
83 if (is_guest_pf(guest_pde_access, shadow_pde_access) == 1) {
84 PrintDebug("Injecting PDE pf to guest: (guest access error=%d) (pf error code=%d)\n",
85 *(uint_t *)&guest_pde_access, *(uint_t *)&error_code);
86 if (inject_guest_pf(info, fault_addr, error_code) == -1) {
87 PrintError("Could not inject guest page fault\n");
95 if (shadow_pde_access == PT_ACCESS_USER_ERROR) {
97 // PDE Entry marked non user
99 PrintDebug("Shadow Paging User access error (shadow_pde_access=0x%x, guest_pde_access=0x%x)\n",
100 shadow_pde_access, guest_pde_access);
102 if (inject_guest_pf(info, fault_addr, error_code) == -1) {
103 PrintError("Could not inject guest page fault\n");
107 } else if ((shadow_pde_access == PT_ACCESS_WRITE_ERROR) &&
108 (guest_pde->large_page == 1)) {
110 ((pde32_4MB_t *)guest_pde)->dirty = 1;
111 shadow_pde->writable = guest_pde->writable;
113 } else if ((shadow_pde_access != PT_ACCESS_NOT_PRESENT) &&
114 (shadow_pde_access != PT_ACCESS_OK)) {
115 // inject page fault in guest
116 if (inject_guest_pf(info, fault_addr, error_code) == -1) {
117 PrintError("Could not inject guest page fault\n");
120 PrintDebug("Unknown Error occurred (shadow_pde_access=%d)\n", shadow_pde_access);
121 PrintDebug("Manual Says to inject page fault into guest\n");
126 pte32_t * shadow_pt = NULL;
127 pte32_t * guest_pt = NULL;
129 // Get the next shadow page level, allocate if not present
131 if (shadow_pde_access == PT_ACCESS_NOT_PRESENT) {
132 struct shadow_page_data * shdw_page = create_new_shadow_pt(info);
133 shadow_pt = (pte32_t *)V3_VAddr((void *)shdw_page->page_pa);
135 shadow_pde->present = 1;
136 shadow_pde->user_page = guest_pde->user_page;
139 if (guest_pde->large_page == 0) {
140 shadow_pde->writable = guest_pde->writable;
142 // This large page flag is temporary until we can get a working cache....
143 ((pde32_4MB_t *)guest_pde)->vmm_info = V3_LARGE_PG;
145 if (error_code.write) {
146 shadow_pde->writable = guest_pde->writable;
147 ((pde32_4MB_t *)guest_pde)->dirty = 1;
149 shadow_pde->writable = 0;
150 ((pde32_4MB_t *)guest_pde)->dirty = 0;
155 // VMM Specific options
156 shadow_pde->write_through = guest_pde->write_through;
157 shadow_pde->cache_disable = guest_pde->cache_disable;
158 shadow_pde->global_page = guest_pde->global_page;
161 guest_pde->accessed = 1;
166 shadow_pde->pt_base_addr = PAGE_BASE_ADDR(shdw_page->page_pa);
168 shadow_pt = (pte32_t *)V3_VAddr((void *)BASE_TO_PAGE_ADDR(shadow_pde->pt_base_addr));
173 if (guest_pde->large_page == 0) {
174 if (guest_pa_to_host_va(info, BASE_TO_PAGE_ADDR(guest_pde->pt_base_addr), (addr_t*)&guest_pt) == -1) {
175 // Machine check the guest
176 PrintDebug("Invalid Guest PTE Address: 0x%p\n", (void *)BASE_TO_PAGE_ADDR(guest_pde->pt_base_addr));
177 v3_raise_exception(info, MC_EXCEPTION);
181 if (handle_pte_shadow_pagefault_32(info, fault_addr, error_code, shadow_pt, guest_pt) == -1) {
182 PrintError("Error handling Page fault caused by PTE\n");
186 if (handle_4MB_shadow_pagefault_32(info, fault_addr, error_code, shadow_pt, (pde32_4MB_t *)guest_pde) == -1) {
187 PrintError("Error handling large pagefault\n");
197 static int handle_pte_shadow_pagefault_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code,
198 pte32_t * shadow_pt, pte32_t * guest_pt) {
200 pt_access_status_t guest_pte_access;
201 pt_access_status_t shadow_pte_access;
202 pte32_t * guest_pte = (pte32_t *)&(guest_pt[PTE32_INDEX(fault_addr)]);;
203 pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(fault_addr)]);
204 addr_t guest_pa = BASE_TO_PAGE_ADDR((addr_t)(guest_pte->page_base_addr)) + PAGE_OFFSET(fault_addr);
206 struct v3_shadow_region * shdw_reg = v3_get_shadow_region(info, guest_pa);
208 if (shdw_reg == NULL) {
209 // Inject a machine check in the guest
210 PrintDebug("Invalid Guest Address in page table (0x%p)\n", (void *)guest_pa);
211 v3_raise_exception(info, MC_EXCEPTION);
215 // Check the guest page permissions
216 guest_pte_access = v3_can_access_pte32(guest_pt, fault_addr, error_code);
218 // Check the shadow page permissions
219 shadow_pte_access = v3_can_access_pte32(shadow_pt, fault_addr, error_code);
222 /* Was the page fault caused by the Guest's page tables? */
223 if (is_guest_pf(guest_pte_access, shadow_pte_access) == 1) {
225 PrintDebug("Access error injecting pf to guest (guest access error=%d) (pf error code=%d)\n",
226 guest_pte_access, *(uint_t*)&error_code);
227 #ifdef CONFIG_SYMBIOTIC_SWAP
228 if (is_swapped_pte32(guest_pte)) {
229 PrintError("Page fault on swapped out page (pte=%x)\n", *(uint32_t *)guest_pte);
231 if (inject_guest_pf(info, fault_addr, error_code) == -1) {
232 PrintError("Could not inject guest page fault\n");
236 if (inject_guest_pf(info, fault_addr, error_code) == -1) {
237 PrintError("Could not inject guest page fault\n");
242 if (inject_guest_pf(info, fault_addr, error_code) == -1) {
243 PrintError("Could not inject guest page fault\n");
253 if (shadow_pte_access == PT_ACCESS_OK) {
254 // Inconsistent state...
255 // Guest Re-Entry will flush page tables and everything should now work
256 PrintDebug("Inconsistent state... Guest re-entry should flush tlb\n");
261 if (shadow_pte_access == PT_ACCESS_NOT_PRESENT) {
262 // Page Table Entry Not Present
263 PrintDebug("guest_pa =%p\n", (void *)guest_pa);
265 if ((shdw_reg->host_type == SHDW_REGION_ALLOCATED) ||
266 (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK)) {
267 addr_t shadow_pa = v3_get_shadow_addr(shdw_reg, guest_pa);
269 shadow_pte->page_base_addr = PAGE_BASE_ADDR(shadow_pa);
271 PrintDebug("\tMapping shadow page (%p)\n", (void *)BASE_TO_PAGE_ADDR(shadow_pte->page_base_addr));
273 shadow_pte->present = guest_pte->present;
274 shadow_pte->user_page = guest_pte->user_page;
276 //set according to VMM policy
277 shadow_pte->write_through = guest_pte->write_through;
278 shadow_pte->cache_disable = guest_pte->cache_disable;
279 shadow_pte->global_page = guest_pte->global_page;
282 guest_pte->accessed = 1;
284 if (guest_pte->dirty == 1) {
285 shadow_pte->writable = guest_pte->writable;
286 } else if ((guest_pte->dirty == 0) && (error_code.write == 1)) {
287 shadow_pte->writable = guest_pte->writable;
288 guest_pte->dirty = 1;
289 } else if ((guest_pte->dirty == 0) && (error_code.write == 0)) {
290 shadow_pte->writable = 0;
295 // Write hooks trump all, and are set Read Only
296 if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
297 shadow_pte->writable = 0;
301 // Page fault handled by hook functions
303 if (v3_handle_mem_full_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
304 PrintError("Special Page fault handler returned error for address: %p\n", (void *)fault_addr);
308 } else if (shadow_pte_access == PT_ACCESS_WRITE_ERROR) {
309 guest_pte->dirty = 1;
311 if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
312 if (v3_handle_mem_wr_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
313 PrintError("Special Page fault handler returned error for address: %p\n", (void *)fault_addr);
317 PrintDebug("Shadow PTE Write Error\n");
318 shadow_pte->writable = guest_pte->writable;
325 // Inject page fault into the guest
326 if (inject_guest_pf(info, fault_addr, error_code) == -1) {
327 PrintError("Could not inject guest page fault\n");
331 PrintError("PTE Page fault fell through... Not sure if this should ever happen\n");
332 PrintError("Manual Says to inject page fault into guest\n");
341 static int handle_4MB_shadow_pagefault_32(struct guest_info * info,
342 addr_t fault_addr, pf_error_t error_code,
343 pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde)
345 pt_access_status_t shadow_pte_access = v3_can_access_pte32(shadow_pt, fault_addr, error_code);
346 pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(fault_addr)]);
347 addr_t guest_fault_pa = BASE_TO_PAGE_ADDR_4MB(large_guest_pde->page_base_addr) + PAGE_OFFSET_4MB(fault_addr);
350 PrintDebug("Handling 4MB fault (guest_fault_pa=%p) (error_code=%x)\n", (void *)guest_fault_pa, *(uint_t*)&error_code);
351 PrintDebug("ShadowPT=%p, LargeGuestPDE=%p\n", shadow_pt, large_guest_pde);
353 struct v3_shadow_region * shdw_reg = v3_get_shadow_region(info, guest_fault_pa);
356 if (shdw_reg == NULL) {
357 // Inject a machine check in the guest
358 PrintDebug("Invalid Guest Address in page table (0x%p)\n", (void *)guest_fault_pa);
359 v3_raise_exception(info, MC_EXCEPTION);
363 if (shadow_pte_access == PT_ACCESS_OK) {
364 // Inconsistent state...
365 // Guest Re-Entry will flush tables and everything should now workd
366 PrintDebug("Inconsistent state... Guest re-entry should flush tlb\n");
371 if (shadow_pte_access == PT_ACCESS_NOT_PRESENT) {
372 // Get the guest physical address of the fault
374 if ((shdw_reg->host_type == SHDW_REGION_ALLOCATED) ||
375 (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK)) {
376 addr_t shadow_pa = v3_get_shadow_addr(shdw_reg, guest_fault_pa);
378 shadow_pte->page_base_addr = PAGE_BASE_ADDR(shadow_pa);
380 PrintDebug("\tMapping shadow page (%p)\n", (void *)BASE_TO_PAGE_ADDR(shadow_pte->page_base_addr));
382 shadow_pte->present = 1;
384 /* We are assuming that the PDE entry has precedence
385 * so the Shadow PDE will mirror the guest PDE settings,
386 * and we don't have to worry about them here
389 shadow_pte->user_page = 1;
391 if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
392 shadow_pte->writable = 0;
394 shadow_pte->writable = 1;
397 //set according to VMM policy
398 shadow_pte->write_through = large_guest_pde->write_through;
399 shadow_pte->cache_disable = large_guest_pde->cache_disable;
400 shadow_pte->global_page = large_guest_pde->global_page;
404 if (v3_handle_mem_full_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
405 PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
409 } else if (shadow_pte_access == PT_ACCESS_WRITE_ERROR) {
411 if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
413 if (v3_handle_mem_wr_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
414 PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
420 PrintError("Error in large page fault handler...\n");
421 PrintError("This case should have been handled at the top level handler\n");
425 PrintDebug("Returning from large page fault handler\n");
440 /* If we start to optimize we should look up the guest pages in the cache... */
441 static inline int handle_shadow_invlpg_32(struct guest_info * info, addr_t vaddr) {
442 pde32_t * shadow_pd = (pde32_t *)CR3_TO_PDE32_VA(info->ctrl_regs.cr3);
443 pde32_t * shadow_pde = (pde32_t *)&shadow_pd[PDE32_INDEX(vaddr)];
445 addr_t guest_cr3 = CR3_TO_PDE32_PA(info->shdw_pg_state.guest_cr3);
446 pde32_t * guest_pd = NULL;
449 if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pd) == -1) {
450 PrintError("Invalid Guest PDE Address: 0x%p\n", (void *)guest_cr3);
454 guest_pde = (pde32_t *)&(guest_pd[PDE32_INDEX(vaddr)]);
456 if (guest_pde->large_page == 1) {
457 shadow_pde->present = 0;
458 PrintDebug("Invalidating Large Page\n");
459 } else if (shadow_pde->present == 1) {
460 pte32_t * shadow_pt = (pte32_t *)(addr_t)BASE_TO_PAGE_ADDR_4KB(shadow_pde->pt_base_addr);
461 pte32_t * shadow_pte = (pte32_t *) V3_VAddr( (void*) &shadow_pt[PTE32_INDEX(vaddr)] );
463 PrintDebug("Setting not present\n");
465 shadow_pte->present = 0;