***/
-struct guest_table {
- addr_t cr3;
- struct list_head link;
-};
-
-
-struct backptr {
- addr_t ptr;
- struct list_head link;
-};
-
-
struct shadow_page_data {
- addr_t ptr;
- addr_t guest_addr;
-
- struct list_head backptrs;
- struct list_head guest_tables;
+ v3_reg_t cr3;
+ addr_t page_pa;
+
+ struct list_head page_list_node;
};
-
-
-//DEFINE_HASHTABLE_INSERT(add_cr3_to_cache, addr_t, struct hashtable *);
-//DEFINE_HASHTABLE_SEARCH(find_cr3_in_cache, addr_t, struct hashtable *);
-//DEFINE_HASHTABLE_REMOVE(del_cr3_from_cache, addr_t, struct hashtable *, 0);
-
-
DEFINE_HASHTABLE_INSERT(add_pte_map, addr_t, addr_t);
DEFINE_HASHTABLE_SEARCH(find_pte_map, addr_t, addr_t);
//DEFINE_HASHTABLE_REMOVE(del_pte_map, addr_t, addr_t, 0);
return (key1 == key2);
}
-static addr_t create_new_shadow_pt();
+static addr_t create_new_shadow_pt(struct guest_info * info);
static void inject_guest_pf(struct guest_info * info, addr_t fault_addr, pf_error_t error_code);
static int is_guest_pf(pt_access_status_t guest_access, pt_access_status_t shadow_access);
state->guest_cr3 = 0;
state->guest_cr0 = 0;
+ INIT_LIST_HEAD(&(state->page_list));
+
state->cached_ptes = NULL;
state->cached_cr3 = 0;
-static addr_t create_new_shadow_pt() {
- void * host_pde = 0;
+static addr_t create_new_shadow_pt(struct guest_info * info) {
+ struct shadow_page_state * state = &(info->shdw_pg_state);
+ v3_reg_t cur_cr3 = info->ctrl_regs.cr3;
+ struct shadow_page_data * page_tail = NULL;
+ addr_t shdw_page = 0;
+
+ if (!list_empty(&(state->page_list))) {
+ page_tail = list_tail_entry(&(state->page_list), struct shadow_page_data, page_list_node);
+
+ if (page_tail->cr3 != cur_cr3) {
+ page_tail->cr3 = cur_cr3;
+ list_move(&(page_tail->page_list_node), &(state->page_list));
+
+ memset(V3_VAddr((void *)(page_tail->page_pa)), 0, PAGE_SIZE_4KB);
+ PrintDebug("Reusing old shadow Page\n");
+
+ return (addr_t)V3_VAddr((void *)(page_tail->page_pa));
+ }
+ }
+
+ // else
+
+ page_tail = (struct shadow_page_data *)V3_Malloc(sizeof(struct shadow_page_data));
+ page_tail->page_pa = (addr_t)V3_AllocPages(1);
- host_pde = V3_VAddr(V3_AllocPages(1));
- memset(host_pde, 0, PAGE_SIZE);
+ page_tail->cr3 = cur_cr3;
+ list_add(&(page_tail->page_list_node), &(state->page_list));
- return (addr_t)host_pde;
+ shdw_page = (addr_t)V3_VAddr((void *)(page_tail->page_pa));
+ memset((void *)shdw_page, 0, PAGE_SIZE_4KB);
+
+ return shdw_page;
}
static int is_guest_pf(pt_access_status_t guest_access, pt_access_status_t shadow_access) {
/* basically the reasoning is that there can be multiple reasons for a page fault:
- If there is a permissions failure for a page present in the guest _BUT_
- the reason for the fault was that the page is not present in the shadow,
- _THEN_ we have to map the shadow page in and reexecute, this will generate
+ If there is a permissions failure for a page present in the guest _BUT_
+ the reason for the fault was that the page is not present in the shadow,
+ _THEN_ we have to map the shadow page in and reexecute, this will generate
a permissions fault which is _THEN_ valid to send to the guest
_UNLESS_ both the guest and shadow have marked the page as not present
*/
if (guest_access != PT_ACCESS_OK) {
// Guest Access Error
-
+
if ((shadow_access != PT_ACCESS_NOT_PRESENT) &&
(guest_access != PT_ACCESS_NOT_PRESENT)) {
// aka (guest permission error)
}
if ((shadow_access == PT_ACCESS_NOT_PRESENT) &&
- (guest_access == PT_ACCESS_NOT_PRESENT)) {
+ (guest_access == PT_ACCESS_NOT_PRESENT)) {
// Page tables completely blank, handle guest first
return 1;
}