*/
-static int cache_page_tables_32(struct guest_info * info, addr_t pde) {
- struct shadow_page_state * state = &(info->shdw_pg_state);
- addr_t pde_host_addr;
- pde32_t * tmp_pde;
- struct hashtable * pte_cache = NULL;
- int i = 0;
-
- if (pde == state->cached_cr3) {
- return 1;
- }
-
- if (state->cached_ptes != NULL) {
- hashtable_destroy(state->cached_ptes, 0, 0);
- state->cached_ptes = NULL;
- }
-
- state->cached_cr3 = pde;
-
- pte_cache = create_hashtable(0, &pte_hash_fn, &pte_equals);
- state->cached_ptes = pte_cache;
-
- if (guest_pa_to_host_va(info, pde, &pde_host_addr) == -1) {
- PrintError("Could not lookup host address of guest PDE\n");
- return -1;
- }
-
- tmp_pde = (pde32_t *)pde_host_addr;
-
- add_pte_map(pte_cache, pde, pde_host_addr);
-
-
- for (i = 0; i < MAX_PDE32_ENTRIES; i++) {
- if ((tmp_pde[i].present) && (tmp_pde[i].large_page == 0)) {
- addr_t pte_host_addr;
-
- if (guest_pa_to_host_va(info, (addr_t)(BASE_TO_PAGE_ADDR(tmp_pde[i].pt_base_addr)), &pte_host_addr) == -1) {
- PrintError("Could not lookup host address of guest PDE\n");
- return -1;
- }
-
- add_pte_map(pte_cache, (addr_t)(BASE_TO_PAGE_ADDR(tmp_pde[i].pt_base_addr)), pte_host_addr);
- }
- }
-
- return 0;
-
-}
-
-// We assume that shdw_pg_state.guest_cr3 is pointing to the page tables we want to activate
-// We also assume that the CPU mode has not changed during this page table transition
static inline int activate_shadow_pt_32(struct guest_info * info) {
struct cr3_32 * shadow_cr3 = (struct cr3_32 *)&(info->ctrl_regs.cr3);
struct cr3_32 * guest_cr3 = (struct cr3_32 *)&(info->shdw_pg_state.guest_cr3);
- int cached = 0;
-
- // Check if shadow page tables are in the cache
- cached = cache_page_tables_32(info, CR3_TO_PDE32_PA(*(addr_t *)guest_cr3));
-
- if (cached == -1) {
- PrintError("CR3 Cache failed\n");
- return -1;
- } else if (cached == 0) {
- struct shadow_page_data * shdw_page = create_new_shadow_pt(info);
+ struct shadow_page_data * shdw_page = create_new_shadow_pt(info);
- shdw_page->cr3 = shdw_page->page_pa;
+ shdw_page->cr3 = shdw_page->page_pa;
- shadow_cr3->pdt_base_addr = PAGE_BASE_ADDR(shdw_page->page_pa);
- PrintDebug( "Created new shadow page table %p\n", (void *)BASE_TO_PAGE_ADDR(shadow_cr3->pdt_base_addr));
- } else {
- PrintDebug("Reusing cached shadow Page table\n");
- }
+ shadow_cr3->pdt_base_addr = PAGE_BASE_ADDR(shdw_page->page_pa);
+ PrintDebug( "Created new shadow page table %p\n", (void *)BASE_TO_PAGE_ADDR(shadow_cr3->pdt_base_addr));
shadow_cr3->pwt = guest_cr3->pwt;
shadow_cr3->pcd = guest_cr3->pcd;
pt_access_status_t shadow_pte_access = v3_can_access_pte32(shadow_pt, fault_addr, error_code);
pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(fault_addr)]);
addr_t guest_fault_pa = BASE_TO_PAGE_ADDR_4MB(large_guest_pde->page_base_addr) + PAGE_OFFSET_4MB(fault_addr);
- struct shadow_page_state * state = &(info->shdw_pg_state);
struct v3_shadow_region * shdw_reg = v3_get_shadow_region(info, guest_fault_pa);
*/
shadow_pte->user_page = 1;
- if (find_pte_map(state->cached_ptes, PAGE_ADDR(guest_fault_pa)) != NULL) {
- // Check if the entry is a page table...
- PrintDebug("Marking page as Guest Page Table (large page)\n");
- shadow_pte->writable = 0;
- } else if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
+ if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
shadow_pte->writable = 0;
} else {
shadow_pte->writable = 1;
}
- if (find_pte_map(state->cached_ptes, PAGE_ADDR(guest_fault_pa)) != NULL) {
- struct shadow_page_state * state = &(info->shdw_pg_state);
- PrintDebug("Write operation on Guest PAge Table Page (large page)\n");
- state->cached_cr3 = 0;
- shadow_pte->writable = 1;
- }
+
} else {
PrintError("Error in large page fault handler...\n");
pte32_t * guest_pte = (pte32_t *)&(guest_pt[PTE32_INDEX(fault_addr)]);;
pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(fault_addr)]);
addr_t guest_pa = BASE_TO_PAGE_ADDR((addr_t)(guest_pte->page_base_addr)) + PAGE_OFFSET(fault_addr);
- struct shadow_page_state * state = &(info->shdw_pg_state);
struct v3_shadow_region * shdw_reg = v3_get_shadow_region(info, guest_pa);
shadow_pte->writable = 0;
}
- // dirty flag has been set, check if its in the cache
- if (find_pte_map(state->cached_ptes, PAGE_ADDR(guest_pa)) != NULL) {
- if (error_code.write == 1) {
- state->cached_cr3 = 0;
- shadow_pte->writable = guest_pte->writable;
- } else {
- shadow_pte->writable = 0;
- }
- }
+
// Write hooks trump all, and are set Read Only
if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
shadow_pte->writable = guest_pte->writable;
}
- if (find_pte_map(state->cached_ptes, PAGE_ADDR(guest_pa)) != NULL) {
- struct shadow_page_state * state = &(info->shdw_pg_state);
- PrintDebug("Write operation on Guest PAge Table Page\n");
- state->cached_cr3 = 0;
- }
return 0;
