+/*
+ * This file is part of the Palacios Virtual Machine Monitor developed
+ * by the V3VEE Project with funding from the United States National
+ * Science Foundation and the Department of Energy.
+ *
+ * The V3VEE Project is a joint project between Northwestern University
+ * and the University of New Mexico. You can find out more at
+ * http://www.v3vee.org
+ *
+ * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu>
+ * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org>
+ * All rights reserved.
+ *
+ * Author: Jack Lange <jarusl@cs.northwestern.edu>
+ *
+ * This is free software. You are permitted to use,
+ * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
+ */
+
+
#include <palacios/vmm_shadow_paging.h>
#endif
+/***
+ *** There be dragons
+ ***/
+
+
+
+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);
+
+
+
+
+static uint_t pte_hash_fn(addr_t key) {
+ return hash_long(key, 32);
+}
+
+static int pte_equals(addr_t key1, addr_t key2) {
+ return (key1 == key2);
+}
+
+static uint_t cr3_hash_fn(addr_t key) {
+ return hash_long(key, 32);
+}
+
+static int cr3_equals(addr_t key1, addr_t key2) {
+ return (key1 == key2);
+}
static int handle_shadow_pte32_fault(struct guest_info* info,
static int handle_shadow_pagefault32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code);
-int init_shadow_page_state(struct guest_info * info) {
+int v3_init_shadow_page_state(struct guest_info * info) {
struct shadow_page_state * state = &(info->shdw_pg_state);
- state->guest_mode = PDE32;
- state->shadow_mode = PDE32;
state->guest_cr3 = 0;
state->shadow_cr3 = 0;
+
+ state->cr3_cache = create_hashtable(0, &cr3_hash_fn, &cr3_equals);
+
+ state->cached_cr3 = 0;
+ state->cached_ptes = NULL;
+
+ return 0;
+}
+
+
+
+
+/*
+ For now we'll do something a little more lightweight
+int cache_page_tables32(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;
+
+
+ pte_cache = (struct hashtable *)find_cr3_in_cache(state->cr3_cache, pde);
+ if (pte_cache != NULL) {
+ PrintError("CR3 already present in cache\n");
+ state->current_ptes = pte_cache;
+ return 1;
+ } else {
+ PrintError("Creating new CR3 cache entry\n");
+ pte_cache = create_hashtable(0, &pte_hash_fn, &pte_equals);
+ state->current_ptes = pte_cache;
+ add_cr3_to_cache(state->cr3_cache, pde, 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)(PDE32_T_ADDR(tmp_pde[i])), &pte_host_addr) == -1) {
+ PrintError("Could not lookup host address of guest PDE\n");
+ return -1;
+ }
+
+ add_pte_map(pte_cache, (addr_t)(PDE32_T_ADDR(tmp_pde[i])), pte_host_addr);
+ }
+ }
+
+
return 0;
}
+*/
-int handle_shadow_pagefault(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
+int v3_cache_page_tables32(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)(PDE32_T_ADDR(tmp_pde[i])), &pte_host_addr) == -1) {
+ PrintError("Could not lookup host address of guest PDE\n");
+ return -1;
+ }
+
+ add_pte_map(pte_cache, (addr_t)(PDE32_T_ADDR(tmp_pde[i])), pte_host_addr);
+ }
+ }
+
+ return 0;
+
+}
+
+
+
+int v3_replace_shdw_page32(struct guest_info * info, addr_t location, pte32_t * new_page, pte32_t * old_page) {
+ pde32_t * shadow_pd = (pde32_t *)CR3_TO_PDE32(info->shdw_pg_state.shadow_cr3);
+ pde32_t * shadow_pde = (pde32_t *)&(shadow_pd[PDE32_INDEX(location)]);
+
+ if (shadow_pde->large_page == 0) {
+ pte32_t * shadow_pt = (pte32_t *)(addr_t)PDE32_T_ADDR((*shadow_pde));
+ pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(location)]);
+
+ //if (shadow_pte->present == 1) {
+ *(uint_t *)old_page = *(uint_t *)shadow_pte;
+ //}
+
+ *(uint_t *)shadow_pte = *(uint_t *)new_page;
+
+ } else {
+ // currently unhandled
+ return -1;
+ }
+
+ return 0;
+}
+
+
+
+
+
+
+int v3_handle_shadow_pagefault(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
if (info->mem_mode == PHYSICAL_MEM) {
// If paging is not turned on we need to handle the special cases
- return handle_special_page_fault(info, fault_addr, error_code);
+ return handle_special_page_fault(info, fault_addr, fault_addr, error_code);
} else if (info->mem_mode == VIRTUAL_MEM) {
switch (info->cpu_mode) {
}
}
-addr_t create_new_shadow_pt32(struct guest_info * info) {
+addr_t v3_create_new_shadow_pt32() {
void * host_pde = 0;
- host_pde = V3_AllocPages(1);
+ host_pde = V3_VAddr(V3_AllocPages(1));
memset(host_pde, 0, PAGE_SIZE);
return (addr_t)host_pde;
}
-static int handle_pd32_nonaligned_4MB_page(struct guest_info * info, pte32_t * pt, addr_t guest_addr, pde32_4MB_t * large_shadow_pde) {
- uint_t i = 0;
- pte32_t * pte_cursor;
- addr_t guest_pa = 0;
-
- for (i = 0; i < 1024; i++) {
- guest_pa = guest_addr + (PAGE_SIZE * i);
- host_region_type_t host_page_type = get_shadow_addr_type(info, guest_pa);
-
- pte_cursor = &(pt[i]);
-
- if (host_page_type == HOST_REGION_INVALID) {
- // Currently we don't support this, but in theory we could
- PrintError("Invalid Host Memory Type\n");
- return -1;
- } else if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) {
- addr_t shadow_pa = get_shadow_addr(info, guest_pa);
-
-
- pte_cursor->page_base_addr = PT32_BASE_ADDR(shadow_pa);
- pte_cursor->present = 1;
- pte_cursor->writable = large_shadow_pde->writable;
- pte_cursor->user_page = large_shadow_pde->user_page;
- pte_cursor->write_through = 0;
- pte_cursor->cache_disable = 0;
- pte_cursor->global_page = 0;
-
- } else {
- PrintError("Unsupported Host Memory Type\n");
- return -1;
- }
- }
- return 0;
+static void inject_guest_pf(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
+ info->ctrl_regs.cr2 = fault_addr;
+ v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code);
}
-static int handle_shadow_pagefault32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
- pde32_t * guest_pd = NULL;
- pde32_t * shadow_pd = (pde32_t *)CR3_TO_PDE32(info->shdw_pg_state.shadow_cr3);
- addr_t guest_cr3 = CR3_TO_PDE32(info->shdw_pg_state.guest_cr3);
- pt_access_status_t guest_pde_access;
- pt_access_status_t shadow_pde_access;
- pde32_t * guest_pde = NULL;
- pde32_t * shadow_pde = (pde32_t *)&(shadow_pd[PDE32_INDEX(fault_addr)]);
-
- if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pd) == -1) {
- PrintError("Invalid Guest PDE Address: 0x%x\n", guest_cr3);
- return -1;
- }
-
-
- guest_pde = (pde32_t *)&(guest_pd[PDE32_INDEX(fault_addr)]);
- // Check the guest page permissions
- guest_pde_access = can_access_pde32(guest_pd, fault_addr, error_code);
-
- // Check the shadow page permissions
- shadow_pde_access = can_access_pde32(shadow_pd, fault_addr, error_code);
-
- /* This should be redone,
- but basically the reasoning is that there can be multiple reasons for a page fault:
+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
whew...
*/
- if ((guest_pde_access != PT_ACCESS_OK) &&
- (
- ( (shadow_pde_access != PT_ENTRY_NOT_PRESENT) &&
- (guest_pde_access != PT_ENTRY_NOT_PRESENT)) // aka (guest permission error)
- ||
- ( (shadow_pde_access == PT_ENTRY_NOT_PRESENT) &&
- (guest_pde_access == PT_ENTRY_NOT_PRESENT)))) {
- // inject page fault to the guest (Guest PDE fault)
-
- info->ctrl_regs.cr2 = fault_addr;
- v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code);
-
-
- PrintDebug("Injecting PDE pf to guest: (guest access error=%d) (pf error code=%d)\n", guest_pde_access, error_code);
- return 0;
+ if (guest_access != PT_ACCESS_OK) {
+ // Guest Access Error
+
+ if ((shadow_access != PT_ENTRY_NOT_PRESENT) &&
+ (guest_access != PT_ENTRY_NOT_PRESENT)) {
+ // aka (guest permission error)
+ return 1;
+ }
-
-#ifdef DEBUG_SHADOW_PAGING
- PrintDebug("Guest CR3=%x\n", guest_cr3);
- PrintDebug("Guest PD\n");
- PrintPD32(guest_pd);
- PrintDebug("Shadow PD\n");
- PrintPD32(shadow_pd);
-#endif
+ if ((shadow_access == PT_ENTRY_NOT_PRESENT) &&
+ (guest_access == PT_ENTRY_NOT_PRESENT)) {
+ // Page tables completely blank, handle guest first
+ return 1;
+ }
- return -1;
+ // Otherwise we'll handle the guest fault later...?
}
+ return 0;
+}
- //shadow_pde_access = can_access_pde32(shadow_pd, fault_addr, error_code);
- if (shadow_pde_access == PT_ENTRY_NOT_PRESENT) {
- shadow_pde->present = 1;
- shadow_pde->user_page = guest_pde->user_page;
- shadow_pde->large_page = guest_pde->large_page;
+/* The guest status checks have already been done,
+ * only special case shadow checks remain
+ */
+static int handle_large_pagefault32(struct guest_info * info,
+ addr_t fault_addr, pf_error_t error_code,
+ pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde)
+{
+ pt_access_status_t shadow_pte_access = can_access_pte32(shadow_pt, fault_addr, error_code);
+ pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(fault_addr)]);
+
+ if (shadow_pte_access == PT_ACCESS_OK) {
+ // Inconsistent state...
+ // Guest Re-Entry will flush tables and everything should now workd
+ PrintDebug("Inconsistent state... Guest re-entry should flush tlb\n");
+ return 0;
+ }
+
+ if (shadow_pte_access == PT_ENTRY_NOT_PRESENT) {
+ // Get the guest physical address of the fault
+ addr_t guest_fault_pa = PDE32_4MB_T_ADDR(*large_guest_pde) + PD32_4MB_PAGE_OFFSET(fault_addr);
+ host_region_type_t host_page_type = get_shadow_addr_type(info, guest_fault_pa);
+
- // VMM Specific options
- shadow_pde->write_through = 0;
- shadow_pde->cache_disable = 0;
- shadow_pde->global_page = 0;
- //
+ if (host_page_type == HOST_REGION_INVALID) {
+ // Inject a machine check in the guest
+ PrintDebug("Invalid Guest Address in page table (0x%x)\n", guest_fault_pa);
+ v3_raise_exception(info, MC_EXCEPTION);
+ return 0;
+ }
- guest_pde->accessed = 1;
-
- if (guest_pde->large_page == 0) {
- pte32_t * shadow_pt = NULL;
-
- shadow_pt = V3_AllocPages(1);
- memset(shadow_pt, 0, PAGE_SIZE);
-
- shadow_pde->pt_base_addr = PD32_BASE_ADDR(shadow_pt);
+ if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) {
+ struct shadow_page_state * state = &(info->shdw_pg_state);
+ addr_t shadow_pa = get_shadow_addr(info, guest_fault_pa);
- shadow_pde->writable = guest_pde->writable;
- } else {
- struct shadow_region * mem_reg;
- pde32_4MB_t * large_guest_pde = (pde32_4MB_t *)guest_pde;
- pde32_4MB_t * large_shadow_pde = (pde32_4MB_t *)shadow_pde;
- host_region_type_t host_page_type;
- addr_t guest_start_addr = PDE32_4MB_T_ADDR(*large_guest_pde);
- // addr_t guest_end_addr = guest_start_addr + PAGE_SIZE_4MB; // start address + 4MB
+ shadow_pte->page_base_addr = PT32_BASE_ADDR(shadow_pa);
+ shadow_pte->present = 1;
- // Check that the Guest PDE entry points to valid memory
- // else Machine Check the guest
- PrintDebug("Large Page: Page Base Addr=%x\n", guest_start_addr);
+ /* We are assuming that the PDE entry has precedence
+ * so the Shadow PDE will mirror the guest PDE settings,
+ * and we don't have to worry about them here
+ * Allow everything
+ */
+ shadow_pte->user_page = 1;
- host_page_type = get_shadow_addr_type(info, guest_start_addr);
+ if (find_pte_map(state->cached_ptes, PT32_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->vmm_info = PT32_GUEST_PT;
+ shadow_pte->writable = 0;
+ } else {
+ shadow_pte->writable = 1;
+ }
- if (host_page_type == HOST_REGION_INVALID) {
- v3_raise_exception(info, MC_EXCEPTION);
- PrintError("Invalid guest address in large page (0x%x)\n", guest_start_addr);
+ //set according to VMM policy
+ shadow_pte->write_through = 0;
+ shadow_pte->cache_disable = 0;
+ shadow_pte->global_page = 0;
+ //
+
+ } else {
+ // Handle hooked pages as well as other special pages
+ if (handle_special_page_fault(info, fault_addr, guest_fault_pa, error_code) == -1) {
+ PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
return -1;
- } else if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) {
- addr_t host_start_addr = 0;
- addr_t region_end_addr = 0;
-
- // Check for a large enough region in host memory
- mem_reg = get_shadow_region_by_addr(&(info->mem_map), guest_start_addr);
- PrintDebug("Host region: host_addr=%x (guest_start=%x, end=%x)\n",
- mem_reg->host_addr, mem_reg->guest_start, mem_reg->guest_end);
- host_start_addr = mem_reg->host_addr + (guest_start_addr - mem_reg->guest_start);
- region_end_addr = mem_reg->host_addr + (mem_reg->guest_end - mem_reg->guest_start);
+ }
+ }
+ } else if ((shadow_pte_access == PT_WRITE_ERROR) &&
+ (shadow_pte->vmm_info == PT32_GUEST_PT)) {
- PrintDebug("Host Start Addr=%x; Region End Addr=%x\n", host_start_addr, region_end_addr);
+ 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");
+ PrintError("This case should have been handled at the top level handler\n");
+ return -1;
+ }
+ PrintDebug("Returning from large page fault handler\n");
+ return 0;
+}
- //4f
- if (large_guest_pde->dirty == 1) { // dirty
- large_shadow_pde->writable = guest_pde->writable;
- } else if (error_code.write == 1) { // not dirty, access is write
- large_shadow_pde->writable = guest_pde->writable;
- large_guest_pde->dirty = 1;
- } else { // not dirty, access is read
- large_shadow_pde->writable = 0;
- }
+static int handle_shadow_pagefault32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
+ pde32_t * guest_pd = NULL;
+ pde32_t * shadow_pd = (pde32_t *)CR3_TO_PDE32(info->shdw_pg_state.shadow_cr3);
+ addr_t guest_cr3 = (addr_t)CR3_TO_PDE32(info->shdw_pg_state.guest_cr3);
+ pt_access_status_t guest_pde_access;
+ pt_access_status_t shadow_pde_access;
+ pde32_t * guest_pde = NULL;
+ pde32_t * shadow_pde = (pde32_t *)&(shadow_pd[PDE32_INDEX(fault_addr)]);
+ PrintDebug("Shadow page fault handler\n");
- // Check if the region is at least an additional 4MB
+ if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pd) == -1) {
+ PrintError("Invalid Guest PDE Address: 0x%p\n", (void *)guest_cr3);
+ return -1;
+ }
+ guest_pde = (pde32_t *)&(guest_pd[PDE32_INDEX(fault_addr)]);
- //4b.
- if ((PD32_4MB_PAGE_OFFSET(host_start_addr) == 0) &&
- (region_end_addr >= host_start_addr + PAGE_SIZE_4MB)) { // if 4MB boundary
- large_shadow_pde->page_base_addr = PD32_4MB_BASE_ADDR(host_start_addr);
- } else { // else generate 4k pages
- pte32_t * shadow_pt = NULL;
- PrintDebug("Handling non aligned large page\n");
- shadow_pde->large_page = 0;
-
- shadow_pt = V3_AllocPages(1);
- memset(shadow_pt, 0, PAGE_SIZE);
+ // Check the guest page permissions
+ guest_pde_access = can_access_pde32(guest_pd, fault_addr, error_code);
- if (handle_pd32_nonaligned_4MB_page(info, shadow_pt, guest_start_addr, large_shadow_pde) == -1) {
- PrintError("Non Aligned Large Page Error\n");
- V3_Free(shadow_pt);
- return -1;
- }
+ // Check the shadow page permissions
+ shadow_pde_access = can_access_pde32(shadow_pd, fault_addr, error_code);
+
+ /* Was the page fault caused by the Guest's page tables? */
+ if (is_guest_pf(guest_pde_access, shadow_pde_access) == 1) {
+ PrintDebug("Injecting PDE pf to guest: (guest access error=%d) (pf error code=%d)\n",
+ guest_pde_access, error_code);
+ inject_guest_pf(info, fault_addr, error_code);
+ return 0;
+ }
+
+ if (shadow_pde_access == PT_ENTRY_NOT_PRESENT)
+ {
+ pte32_t * shadow_pt = (pte32_t *)v3_create_new_shadow_pt32();
+
+ shadow_pde->present = 1;
+ shadow_pde->user_page = guest_pde->user_page;
+ // shadow_pde->large_page = guest_pde->large_page;
+ shadow_pde->large_page = 0;
+
-#ifdef DEBUG_SHADOW_PAGING
- PrintDebug("non-aligned Shadow PT\n");
- PrintPT32(PT32_PAGE_ADDR(fault_addr), shadow_pt);
-#endif
- shadow_pde->pt_base_addr = PD32_BASE_ADDR(shadow_pt);
+ // VMM Specific options
+ shadow_pde->write_through = 0;
+ shadow_pde->cache_disable = 0;
+ shadow_pde->global_page = 0;
+ //
+
+ guest_pde->accessed = 1;
+
+ shadow_pde->pt_base_addr = PD32_BASE_ADDR((addr_t)V3_PAddr(shadow_pt));
+
+ if (guest_pde->large_page == 0) {
+ shadow_pde->writable = guest_pde->writable;
+ } else {
+ // ?? What if guest pde is dirty a this point?
+ ((pde32_4MB_t *)guest_pde)->dirty = 0;
+ shadow_pde->writable = 0;
+ }
+ }
+ else if (shadow_pde_access == PT_ACCESS_OK)
+ {
+ //
+ // PTE fault
+ //
+ pte32_t * shadow_pt = (pte32_t *)(addr_t)PDE32_T_ADDR((*shadow_pde));
+
+ if (guest_pde->large_page == 0) {
+ pte32_t * guest_pt = NULL;
+ if (guest_pa_to_host_va(info, PDE32_T_ADDR((*guest_pde)), (addr_t*)&guest_pt) == -1) {
+ // Machine check the guest
+ PrintDebug("Invalid Guest PTE Address: 0x%x\n", PDE32_T_ADDR((*guest_pde)));
+ v3_raise_exception(info, MC_EXCEPTION);
+ return 0;
}
-
- } else {
- // Handle hooked pages as well as other special pages
- if (handle_special_page_fault(info, fault_addr, error_code) == -1) {
- PrintError("Special Page Fault handler returned error for address: %x\n", fault_addr);
+ if (handle_shadow_pte32_fault(info, fault_addr, error_code, shadow_pt, guest_pt) == -1) {
+ PrintError("Error handling Page fault caused by PTE\n");
+ return -1;
+ }
+ } else if (guest_pde->large_page == 1) {
+ if (handle_large_pagefault32(info, fault_addr, error_code, shadow_pt, (pde32_4MB_t *)guest_pde) == -1) {
+ PrintError("Error handling large pagefault\n");
return -1;
}
}
}
+ else if ((shadow_pde_access == PT_WRITE_ERROR) &&
+ (guest_pde->large_page == 1) &&
+ (((pde32_4MB_t *)guest_pde)->dirty == 0))
+ {
+ //
+ // Page Directory Entry marked read-only
+ // Its a large page and we need to update the dirty bit in the guest
+ //
- } else if ((shadow_pde_access == PT_WRITE_ERROR) &&
- (guest_pde->large_page = 1) &&
- (((pde32_4MB_t *)guest_pde)->dirty == 0)) {
-
- //
- // Page Directory Entry marked read-only
- //
-
- ((pde32_4MB_t *)guest_pde)->dirty = 1;
- shadow_pde->writable = guest_pde->writable;
- return 0;
-
- } else if (shadow_pde_access == PT_USER_ERROR) {
-
- //
- // Page Directory Entry marked non-user
- //
-
- PrintDebug("Shadow Paging User access error (shadow_pde_access=0x%x, guest_pde_access=0x%x - injecting into guest\n", shadow_pde_access, guest_pde_access);
- info->ctrl_regs.cr2 = fault_addr;
- v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code);
- return 0;
-
- } else if (shadow_pde_access == PT_ACCESS_OK) {
- pte32_t * shadow_pt = (pte32_t *)PDE32_T_ADDR((*shadow_pde));
- pte32_t * guest_pt = NULL;
-
- // Page Table Entry fault
-
- if (guest_pa_to_host_va(info, PDE32_T_ADDR((*guest_pde)), (addr_t*)&guest_pt) == -1) {
- PrintDebug("Invalid Guest PTE Address: 0x%x\n", PDE32_T_ADDR((*guest_pde)));
- // Machine check the guest
-
- v3_raise_exception(info, MC_EXCEPTION);
+ PrintDebug("Large page write error... Setting dirty bit and returning\n");
+ ((pde32_4MB_t *)guest_pde)->dirty = 1;
+ shadow_pde->writable = guest_pde->writable;
+ return 0;
+ }
+ else if (shadow_pde_access == PT_USER_ERROR)
+ {
+ //
+ // Page Directory Entry marked non-user
+ //
+ PrintDebug("Shadow Paging User access error (shadow_pde_access=0x%x, guest_pde_access=0x%x)\n",
+ shadow_pde_access, guest_pde_access);
+ inject_guest_pf(info, fault_addr, error_code);
return 0;
}
+ else
+ {
+ // inject page fault in guest
+ inject_guest_pf(info, fault_addr, error_code);
+ PrintDebug("Unknown Error occurred (shadow_pde_access=%d)\n", shadow_pde_access);
+ PrintDebug("Manual Says to inject page fault into guest\n");
+#ifdef DEBUG_SHADOW_PAGING
+ PrintDebug("Guest PDE: (access=%d)\n\t", guest_pde_access);
+ PrintPDE32(fault_addr, guest_pde);
+ PrintDebug("Shadow PDE: (access=%d)\n\t", shadow_pde_access);
+ PrintPDE32(fault_addr, shadow_pde);
+#endif
-
- if (handle_shadow_pte32_fault(info, fault_addr, error_code, shadow_pt, guest_pt) == -1) {
- PrintError("Error handling Page fault caused by PTE\n");
- return -1;
+ return 0;
}
- } else {
- // Unknown error raise page fault in guest
- info->ctrl_regs.cr2 = fault_addr;
- v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code);
-
- // For debugging we will return an error here for the time being,
- // this probably shouldn't ever happen
- PrintDebug("Unknown Error occurred\n");
- PrintDebug("Manual Says to inject page fault into guest\n");
-
-
- return 0;
-
- }
-
- //PrintDebugPageTables(shadow_pd);
PrintDebug("Returning end of PDE function (rip=%x)\n", info->rip);
return 0;
}
* We assume the the guest pte pointer has already been translated to a host virtual address
*/
static int handle_shadow_pte32_fault(struct guest_info * info,
- addr_t fault_addr,
- pf_error_t error_code,
- pte32_t * shadow_pt,
- pte32_t * guest_pt) {
+ addr_t fault_addr,
+ pf_error_t error_code,
+ pte32_t * shadow_pt,
+ pte32_t * guest_pt) {
pt_access_status_t guest_pte_access;
pt_access_status_t shadow_pte_access;
PrintPTE32(fault_addr, shadow_pte);
#endif
- /* This should be redone,
- but 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
- 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
-
- whew...
- */
- if ((guest_pte_access != PT_ACCESS_OK) &&
- (
- ((shadow_pte_access != PT_ENTRY_NOT_PRESENT) &&
- (guest_pte_access != PT_ENTRY_NOT_PRESENT)) // aka (guest permission error)
- ||
- ((shadow_pte_access == PT_ENTRY_NOT_PRESENT) &&
- (guest_pte_access == PT_ENTRY_NOT_PRESENT)))) {
- // Inject page fault into the guest
-
- info->ctrl_regs.cr2 = fault_addr;
- v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code);
-
- PrintDebug("Access error injecting pf to guest (guest access error=%d) (pf error code=%d)\n", guest_pte_access, *(uint_t*)&error_code);
+ /* Was the page fault caused by the Guest's page tables? */
+ if (is_guest_pf(guest_pte_access, shadow_pte_access) == 1) {
+ PrintDebug("Access error injecting pf to guest (guest access error=%d) (pf error code=%d)\n",
+ guest_pte_access, *(uint_t*)&error_code);
+ inject_guest_pf(info, fault_addr, error_code);
return 0;
}
-
-
if (shadow_pte_access == PT_ACCESS_OK) {
// Inconsistent state...
// Guest Re-Entry will flush page tables and everything should now work
PrintDebug("Inconsistent state... Guest re-entry should flush tlb\n");
return 0;
- } else if (shadow_pte_access == PT_ENTRY_NOT_PRESENT) {
- addr_t shadow_pa;
- addr_t guest_pa = PTE32_T_ADDR((*guest_pte));
+ }
+
+
+ if (shadow_pte_access == PT_ENTRY_NOT_PRESENT) {
+
+ addr_t guest_pa = PTE32_T_ADDR((*guest_pte)) + PT32_PAGE_OFFSET(fault_addr);
// Page Table Entry Not Present
if (host_page_type == HOST_REGION_INVALID) {
// Inject a machine check in the guest
-
- v3_raise_exception(info, MC_EXCEPTION);
-#ifdef DEBUG_SHADOW_PAGING
PrintDebug("Invalid Guest Address in page table (0x%x)\n", guest_pa);
- PrintDebug("fault_addr=0x%x next are guest and shadow ptes \n",fault_addr);
- PrintPTE32(fault_addr,guest_pte);
- PrintPTE32(fault_addr,shadow_pte);
- PrintDebug("Done.\n");
-#endif
+ v3_raise_exception(info, MC_EXCEPTION);
return 0;
+ }
- } else if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) {
-
- shadow_pa = get_shadow_addr(info, guest_pa);
+ // else...
+
+ if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) {
+ struct shadow_page_state * state = &(info->shdw_pg_state);
+ addr_t shadow_pa = get_shadow_addr(info, guest_pa);
shadow_pte->page_base_addr = PT32_BASE_ADDR(shadow_pa);
guest_pte->accessed = 1;
+ if (find_pte_map(state->cached_ptes, PT32_PAGE_ADDR(guest_pa)) != NULL) {
+ // Check if the entry is a page table...
+ PrintDebug("Marking page as Guest Page Table\n", shadow_pte->writable);
+ shadow_pte->vmm_info = PT32_GUEST_PT;
+ }
+
if (guest_pte->dirty == 1) {
shadow_pte->writable = guest_pte->writable;
} else if ((guest_pte->dirty == 0) && (error_code.write == 1)) {
shadow_pte->writable = guest_pte->writable;
guest_pte->dirty = 1;
- } else if ((guest_pte->dirty = 0) && (error_code.write == 0)) {
+
+ if (shadow_pte->vmm_info == PT32_GUEST_PT) {
+ // Well that was quick...
+ struct shadow_page_state * state = &(info->shdw_pg_state);
+ PrintDebug("Immediate Write operation on Guest PAge Table Page\n");
+ state->cached_cr3 = 0;
+ }
+
+ } else if ((guest_pte->dirty == 0) && (error_code.write == 0)) { // was =
shadow_pte->writable = 0;
}
+
+
+
} else {
// Page fault handled by hook functions
- if (handle_special_page_fault(info, fault_addr, error_code) == -1) {
- PrintError("Special Page fault handler returned error for address: %x\n", fault_addr);
+ if (handle_special_page_fault(info, fault_addr, guest_pa, error_code) == -1) {
+ PrintError("Special Page fault handler returned error for address: %p\n", (void *)fault_addr);
return -1;
}
}
} else if ((shadow_pte_access == PT_WRITE_ERROR) &&
(guest_pte->dirty == 0)) {
- guest_pte->dirty = 1;
- shadow_pte->writable = guest_pte->writable;
PrintDebug("Shadow PTE Write Error\n");
+ guest_pte->dirty = 1;
+ shadow_pte->writable = guest_pte->writable;
+ if (shadow_pte->vmm_info == PT32_GUEST_PT) {
+ struct shadow_page_state * state = &(info->shdw_pg_state);
+ PrintDebug("Write operation on Guest PAge Table Page\n");
+ state->cached_cr3 = 0;
+ }
+
return 0;
+
} else {
// Inject page fault into the guest
-
- info->ctrl_regs.cr2 = fault_addr;
- v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code);
-
+ inject_guest_pf(info, fault_addr, error_code);
PrintError("PTE Page fault fell through... Not sure if this should ever happen\n");
PrintError("Manual Says to inject page fault into guest\n");
return -1;
/* Currently Does not work with Segmentation!!! */
-int handle_shadow_invlpg(struct guest_info * info) {
+int v3_handle_shadow_invlpg(struct guest_info * info) {
if (info->mem_mode != VIRTUAL_MEM) {
// Paging must be turned on...
// should handle with some sort of fault I think
if (info->cpu_mode == PROTECTED) {
- char instr[15];
+ uchar_t instr[15];
int ret;
int index = 0;
ret = read_guest_va_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
if (ret != 15) {
- PrintError("Could not read instruction 0x%x (ret=%d)\n", info->rip, ret);
+ PrintError("Could not read instruction 0x%p (ret=%d)\n", (void *)(info->rip), ret);
return -1;
}
addr_t first_operand;
addr_t second_operand;
- operand_type_t addr_type;
- addr_t guest_cr3 = CR3_TO_PDE32(info->shdw_pg_state.guest_cr3);
+ v3_operand_type_t addr_type;
+ addr_t guest_cr3 = (addr_t)CR3_TO_PDE32(info->shdw_pg_state.guest_cr3);
pde32_t * guest_pd = NULL;
if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pd) == -1) {
- PrintError("Invalid Guest PDE Address: 0x%x\n", guest_cr3);
+ PrintError("Invalid Guest PDE Address: 0x%p\n", (void *)guest_cr3);
return -1;
}
} else {
if (shadow_pde->present == 1) {
- pte32_t * shadow_pt = (pte32_t *)PDE32_T_ADDR((*shadow_pde));
+ pte32_t * shadow_pt = (pte32_t *)(addr_t)PDE32_T_ADDR((*shadow_pde));
pte32_t * shadow_pte = (pte32_t *)&shadow_pt[PTE32_INDEX(first_operand)];
#ifdef DEBUG_SHADOW_PAGING
}
+/*
+
+
+static int create_pd32_nonaligned_4MB_page(struct guest_info * info, pte32_t * pt, addr_t guest_addr, pde32_4MB_t * large_shadow_pde) {
+ uint_t i = 0;
+ pte32_t * pte_cursor;
+ addr_t guest_pa = 0;
+
+ for (i = 0; i < 1024; i++) {
+ guest_pa = guest_addr + (PAGE_SIZE * i);
+ host_region_type_t host_page_type = get_shadow_addr_type(info, guest_pa);
+
+ pte_cursor = &(pt[i]);
+
+ if (host_page_type == HOST_REGION_INVALID) {
+ // Currently we don't support this, but in theory we could
+ PrintError("Invalid Host Memory Type\n");
+ return -1;
+ } else if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) {
+ addr_t shadow_pa = get_shadow_addr(info, guest_pa);
+
+
+ pte_cursor->page_base_addr = PT32_BASE_ADDR(shadow_pa);
+ pte_cursor->present = 1;
+ pte_cursor->writable = large_shadow_pde->writable;
+ pte_cursor->user_page = large_shadow_pde->user_page;
+ pte_cursor->write_through = 0;
+ pte_cursor->cache_disable = 0;
+ pte_cursor->global_page = 0;
+
+ } else {
+ PrintError("Unsupported Host Memory Type\n");
+ return -1;
+ }
+ }
+ return 0;
+}
+
+
+static int handle_large_pagefault32(struct guest_info * info,
+ pde32_t * guest_pde, pde32_t * shadow_pde,
+ addr_t fault_addr, pf_error_t error_code ) {
+ struct shadow_region * mem_reg;
+ pde32_4MB_t * large_guest_pde = (pde32_4MB_t *)guest_pde;
+ pde32_4MB_t * large_shadow_pde = (pde32_4MB_t *)shadow_pde;
+ host_region_type_t host_page_type;
+ addr_t guest_start_addr = PDE32_4MB_T_ADDR(*large_guest_pde);
+ // addr_t guest_end_addr = guest_start_addr + PAGE_SIZE_4MB; // start address + 4MB
+
+
+ // Check that the Guest PDE entry points to valid memory
+ // else Machine Check the guest
+ PrintDebug("Large Page: Page Base Addr=%x\n", guest_start_addr);
+
+ host_page_type = get_shadow_addr_type(info, guest_start_addr);
+
+ if (host_page_type == HOST_REGION_INVALID) {
+ PrintError("Invalid guest address in large page (0x%x)\n", guest_start_addr);
+ v3_raise_exception(info, MC_EXCEPTION);
+ return -1;
+ }
+
+ // else...
+
+ if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) {
+
+ addr_t host_start_addr = 0;
+ addr_t region_end_addr = 0;
+
+ // Check for a large enough region in host memory
+ mem_reg = get_shadow_region_by_addr(&(info->mem_map), guest_start_addr);
+ PrintDebug("Host region: host_addr=%x (guest_start=%x, end=%x)\n",
+ mem_reg->host_addr, mem_reg->guest_start, mem_reg->guest_end);
+ host_start_addr = mem_reg->host_addr + (guest_start_addr - mem_reg->guest_start);
+ region_end_addr = mem_reg->host_addr + (mem_reg->guest_end - mem_reg->guest_start);
+
+ PrintDebug("Host Start Addr=%x; Region End Addr=%x\n", host_start_addr, region_end_addr);
+
+
+ //4f
+ if (large_guest_pde->dirty == 1) { // dirty
+ large_shadow_pde->writable = guest_pde->writable;
+ } else if (error_code.write == 1) { // not dirty, access is write
+ large_shadow_pde->writable = guest_pde->writable;
+ large_guest_pde->dirty = 1;
+ } else { // not dirty, access is read
+ large_shadow_pde->writable = 0;
+ }
+
+
+ // Check if the region is at least an additional 4MB
+
+
+ //4b.
+ if ((PD32_4MB_PAGE_OFFSET(host_start_addr) == 0) &&
+ (region_end_addr >= host_start_addr + PAGE_SIZE_4MB)) { // if 4MB boundary
+ large_shadow_pde->page_base_addr = PD32_4MB_BASE_ADDR(host_start_addr);
+ } else { // else generate 4k pages
+ pte32_t * shadow_pt = NULL;
+ PrintDebug("Handling non aligned large page\n");
+
+ shadow_pde->large_page = 0;
+
+ shadow_pt = create_new_shadow_pt32();
+
+ if (create_pd32_nonaligned_4MB_page(info, shadow_pt, guest_start_addr, large_shadow_pde) == -1) {
+ PrintError("Non Aligned Large Page Error\n");
+ V3_Free(shadow_pt);
+ return -1;
+ }
+
+
+#ifdef DEBUG_SHADOW_PAGING
+ PrintDebug("non-aligned Shadow PT\n");
+ PrintPT32(PT32_PAGE_ADDR(fault_addr), shadow_pt);
+#endif
+ shadow_pde->pt_base_addr = PD32_BASE_ADDR(shadow_pt);
+ }
+
+ } else {
+ // Handle hooked pages as well as other special pages
+ if (handle_special_page_fault(info, fault_addr, guest_start_addr, error_code) == -1) {
+ PrintError("Special Page Fault handler returned error for address: %x\n", fault_addr);
+ return -1;
+ }
+ }
+
+ return 0;
+}
+*/
