1 #include <palacios/vmm_shadow_paging.h>
4 #include <palacios/vmm.h>
5 #include <palacios/vm_guest_mem.h>
10 int init_shadow_page_state(struct shadow_page_state * state) {
11 state->guest_mode = PDE32;
12 state->shadow_mode = PDE32;
15 state->shadow_cr3 = 0;
20 int handle_shadow_pagefault(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
21 if (info->cpu_mode == PROTECTED_PG) {
22 return handle_shadow_pagefault32(info, fault_addr, error_code);
29 int handle_shadow_pagefault32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
30 pde32_t * guest_pde = NULL;
31 pde32_t * shadow_pde = (pde32_t *)CR3_TO_PDE32(info->shdw_pg_state.shadow_cr3);
32 addr_t guest_cr3 = CR3_TO_PDE32(info->shdw_pg_state.guest_cr3);
33 pt_access_status_t guest_pde_access;
34 pt_access_status_t shadow_pde_access;
35 pde32_t * guest_pde_entry = NULL;
36 pde32_t * shadow_pde_entry = (pde32_t *)&(shadow_pde[PDE32_INDEX(fault_addr)]);
38 if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pde) == -1) {
39 PrintDebug("Invalid Guest PDE Address: 0x%x\n", guest_cr3);
44 guest_pde_entry = (pde32_t *)&(guest_pde[PDE32_INDEX(fault_addr)]);
46 // Check the guest page permissions
47 guest_pde_access = can_access_pde32(guest_pde, fault_addr, error_code);
49 if (guest_pde_access != PT_ACCESS_OK) {
52 // inject page fault to the guest (Guest PDE fault)
55 PrintDebug("Guest Page fault (currently not handled)\n");
59 shadow_pde_access = can_access_pde32(shadow_pde, fault_addr, error_code);
62 if (shadow_pde_access == PT_ENTRY_NOT_PRESENT) {
63 pte32_t * shadow_pte = NULL;
65 V3_AllocPages(shadow_pte, 1);
66 memset(shadow_pte, 0, PAGE_SIZE);
68 shadow_pde_entry->pt_base_addr = PD32_BASE_ADDR(shadow_pte);
71 shadow_pde_entry->present = 1;
72 shadow_pde_entry->user_page = guest_pde_entry->user_page;
74 // VMM Specific options
75 shadow_pde_entry->write_through = 0;
76 shadow_pde_entry->cache_disable = 0;
77 shadow_pde_entry->global_page = 0;
80 guest_pde_entry->accessed = 1;
82 if (guest_pde_entry->large_page == 0) {
83 shadow_pde_entry->writable = guest_pde_entry->writable;
86 * Check the Intel manual because we are ignoring Large Page issues here
90 } else if (shadow_pde_access == PT_WRITE_ERROR) {
93 // Page Directory Entry marked read-only
96 PrintDebug("Shadow Paging Write Error\n");
98 } else if (shadow_pde_access == PT_USER_ERROR) {
101 // Page Directory Entry marked non-user
104 PrintDebug("Shadow Paging User access error\n");
106 } else if (shadow_pde_access == PT_ACCESS_OK) {
107 pte32_t * shadow_pte = (pte32_t *)PDE32_T_ADDR((*shadow_pde_entry));
108 pte32_t * guest_pte = NULL;
110 // Page Table entry fault
112 if (guest_pa_to_host_va(info, PDE32_T_ADDR((*guest_pde_entry)), (addr_t*)&guest_pte) == -1) {
113 PrintDebug("Invalid Guest PTE Address: 0x%x\n", PDE32_T_ADDR((*guest_pde_entry)));
118 if (handle_shadow_pte32_fault(info, fault_addr, error_code, shadow_pte, guest_pte) == -1) {
119 PrintDebug("Error handling Page fault caused by PTE\n");
124 PrintDebug("Unknown Error\n");
128 PrintDebugPageTables(shadow_pde);
136 * We assume the the guest pte pointer has already been translated to a host virtual address
138 int handle_shadow_pte32_fault(struct guest_info* info,
140 pf_error_t error_code,
141 pte32_t * shadow_pte,
142 pte32_t * guest_pte) {
144 pt_access_status_t guest_pte_access;
145 pt_access_status_t shadow_pte_access;
146 pte32_t * guest_pte_entry = (pte32_t *)&(guest_pte[PTE32_INDEX(fault_addr)]);;
147 pte32_t * shadow_pte_entry = (pte32_t *)&(shadow_pte[PTE32_INDEX(fault_addr)]);
150 // Check the guest page permissions
151 guest_pte_access = can_access_pte32(guest_pte, fault_addr, error_code);
153 if (guest_pte_access != PT_ACCESS_OK) {
156 // Inject page fault into the guest
159 PrintDebug("Guest Page fault (currently not handled)\n");
164 shadow_pte_access = can_access_pte32(shadow_pte, fault_addr, error_code);
166 if (shadow_pte_access == PT_ENTRY_NOT_PRESENT) {
168 addr_t guest_pa = PTE32_T_ADDR((*guest_pte_entry));
170 // Page Table Entry Not Present
172 if (get_shadow_addr_type(info, guest_pa) == HOST_REGION_INVALID) {
175 // Inject a machine check in the guest
178 PrintDebug("Invalid Guest Address in page table (0x%x)\n", guest_pa);
182 shadow_pa = get_shadow_addr(info, guest_pa);
184 shadow_pte_entry->page_base_addr = PT32_BASE_ADDR(shadow_pa);
186 shadow_pte_entry->present = guest_pte_entry->present;
187 shadow_pte_entry->user_page = guest_pte_entry->user_page;
189 //set according to VMM policy
190 shadow_pte_entry->write_through = 0;
191 shadow_pte_entry->cache_disable = 0;
192 shadow_pte_entry->global_page = 0;
195 guest_pte_entry->accessed = 1;
197 if (guest_pte_entry->dirty == 1) {
198 shadow_pte_entry->writable = guest_pte_entry->writable;
199 } else if ((guest_pte_entry->dirty == 0) && (error_code.write == 1)) {
200 shadow_pte_entry->writable = guest_pte_entry->writable;
201 guest_pte_entry->dirty = 1;
202 } else if ((guest_pte_entry->dirty = 0) && (error_code.write == 0)) {
203 shadow_pte_entry->writable = 0;
206 } else if (shadow_pte_access == PT_WRITE_ERROR) {
209 // Page Table Entry marked read-only
212 PrintDebug("Shadow Paging Write Error\n");
214 } else if (shadow_pte_access == PT_USER_ERROR) {
217 // Page Table Entry marked non-user
220 PrintDebug("Shadow Paging User access error\n");
222 } else if (shadow_pte_access == PT_ACCESS_OK) {
224 PrintDebug("Page Fault occurred for No Reason\n");
227 PrintDebug("Unknown Error\n");
237 addr_t create_new_shadow_pt32(struct guest_info * info) {
240 V3_AllocPages(host_pde, 1);
241 memset(host_pde, 0, PAGE_SIZE);
243 return (addr_t)host_pde;
249 addr_t setup_shadow_pt32(struct guest_info * info, addr_t virt_cr3) {
250 addr_t cr3_guest_addr = CR3_TO_PDE32(virt_cr3);
252 pde32_t * host_pde = NULL;
255 // Setup up guest_pde to point to the PageDir in host addr
256 if (guest_pa_to_host_va(info, cr3_guest_addr, (addr_t*)&guest_pde) == -1) {
260 V3_AllocPages(host_pde, 1);
261 memset(host_pde, 0, PAGE_SIZE);
263 for (i = 0; i < MAX_PDE32_ENTRIES; i++) {
264 if (guest_pde[i].present == 1) {
268 if (guest_pa_to_host_va(info, PDE32_T_ADDR(guest_pde[i]), &pt_host_addr) == -1) {
272 if ((host_pte = setup_shadow_pte32(info, pt_host_addr)) == 0) {
276 host_pde[i].present = 1;
277 host_pde[i].pt_base_addr = PD32_BASE_ADDR(host_pte);
280 // Set Page DIR flags
285 PrintDebugPageTables(host_pde);
287 return (addr_t)host_pde;
292 addr_t setup_shadow_pte32(struct guest_info * info, addr_t pt_host_addr) {
293 pte32_t * guest_pte = (pte32_t *)pt_host_addr;
294 pte32_t * host_pte = NULL;
297 V3_AllocPages(host_pte, 1);
298 memset(host_pte, 0, PAGE_SIZE);
300 for (i = 0; i < MAX_PTE32_ENTRIES; i++) {
301 if (guest_pte[i].present == 1) {
302 addr_t guest_pa = PTE32_T_ADDR(guest_pte[i]);
303 shadow_mem_type_t page_type;
306 page_type = get_shadow_addr_type(info, guest_pa);
308 if (page_type == HOST_REGION_PHYSICAL_MEMORY) {
309 host_pa = get_shadow_addr(info, guest_pa);
313 // Setup various memory types
317 host_pte[i].page_base_addr = PT32_BASE_ADDR(host_pa);
318 host_pte[i].present = 1;
322 return (addr_t)host_pte;