+/*
+ * 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>
+
#include <palacios/vmm.h>
#include <palacios/vm_guest_mem.h>
+#include <palacios/vmm_decoder.h>
+#include <palacios/vmm_ctrl_regs.h>
+
+#include <palacios/vmm_hashtable.h>
+
+#ifndef DEBUG_SHADOW_PAGING
+#undef PrintDebug
+#define PrintDebug(fmt, args...)
+#endif
+
+
+/***
+ *** There be dragons
+ ***/
+
+
+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;
+};
+
+
+
+
+//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);
+
-extern struct vmm_os_hooks * os_hooks;
+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);
-int init_shadow_page_state(struct shadow_page_state * state) {
- state->guest_mode = PDE32;
- state->shadow_mode = PDE32;
+
+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 activate_shadow_pt_32(struct guest_info * info);
+static int activate_shadow_pt_32pae(struct guest_info * info);
+static int activate_shadow_pt_64(struct guest_info * info);
+
+
+static int handle_shadow_pagefault_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code);
+static int handle_shadow_pagefault_32pae(struct guest_info * info, addr_t fault_addr, pf_error_t error_code);
+static int handle_shadow_pagefault_64(struct guest_info * info, addr_t fault_addr, pf_error_t error_code);
+
+
+static int cache_page_tables_32(struct guest_info * info, addr_t pde);
+static int cache_page_tables_64(struct guest_info * info, addr_t pde);
+
+int v3_init_shadow_page_state(struct guest_info * info) {
+ struct shadow_page_state * state = &(info->shdw_pg_state);
- state->guest_cr3.r_reg = 0;
- state->shadow_cr3.r_reg = 0;
+ state->guest_cr3 = 0;
+ state->guest_cr0 = 0;
+
+ state->cr3_cache = create_hashtable(0, &cr3_hash_fn, &cr3_equals);
+
+ state->cached_cr3 = 0;
+ state->cached_ptes = NULL;
+
+ return 0;
+}
+
+
+
+
+
+int v3_cache_page_tables(struct guest_info * info, addr_t cr3) {
+ switch(v3_get_cpu_mode(info)) {
+ case PROTECTED:
+ return cache_page_tables_32(info, CR3_TO_PDE32_PA(cr3));
+ default:
+ return -1;
+ }
+}
+
+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;
+
+}
+
+
+static int cache_page_tables_64(struct guest_info * info, addr_t pde) {
+ return -1;
}
+
+
+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_VA(info->ctrl_regs.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)BASE_TO_PAGE_ADDR(shadow_pde->pt_base_addr);
+ 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
+ PrintError("Replacing large shadow pages not implemented\n");
+ return -1;
+ }
+ return 0;
+}
-int wholesale_update_shadow_page_state(struct guest_info * guest_info) {
- unsigned i, j;
- pde32_t * guest_pde;
- pde32_t * shadow_pde;
- struct shadow_page_state * state = &(guest_info->shdw_pg_state);
- // For now, we'll only work with PDE32
- if (state->guest_mode != PDE32) {
+
+// 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 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) {
+ addr_t shadow_pt;
+
+ PrintDebug("New CR3 is different - flushing shadow page table %p\n", shadow_cr3 );
+ delete_page_tables_32(CR3_TO_PDE32_VA(*(uint_t*)shadow_cr3));
+
+ shadow_pt = v3_create_new_shadow_pt();
+
+ shadow_cr3->pdt_base_addr = (addr_t)V3_PAddr((void *)(addr_t)PAGE_BASE_ADDR(shadow_pt));
+ PrintDebug( "Created new shadow page table %p\n", (void *)(addr_t)shadow_cr3->pdt_base_addr );
+ } else {
+ PrintDebug("Reusing cached shadow Page table\n");
+ }
+
+ shadow_cr3->pwt = guest_cr3->pwt;
+ shadow_cr3->pcd = guest_cr3->pcd;
+
+ return 0;
+}
+
+static int activate_shadow_pt_32pae(struct guest_info * info) {
+ PrintError("Activating 32 bit PAE page tables not implemented\n");
+ return -1;
+}
+
+static int activate_shadow_pt_64_cb(page_type_t type, addr_t vaddr, addr_t page_ptr, addr_t page_pa, void * private_data) {
+ PrintDebug("CB: Page: %p->%p (host_ptr=%p), Type: %s\n", (void *)vaddr, (void *)page_pa, (void *)page_ptr, v3_page_type_to_str(type));
+ return 0;
+}
+
+
+static int activate_shadow_pt_64(struct guest_info * info) {
+ // struct cr3_64 * shadow_cr3 = (struct cr3_64 *)&(info->ctrl_regs.cr3);
+ struct cr3_64 * guest_cr3 = (struct cr3_64 *)&(info->shdw_pg_state.guest_cr3);
+ int cached = 0;
+
+ v3_walk_guest_pt_64(info, info->shdw_pg_state.guest_cr3, activate_shadow_pt_64_cb, NULL);
+
+
+
+ return -1;
+
+
+ // Check if shadow page tables are in the cache
+ cached = cache_page_tables_64(info, CR3_TO_PDE32_PA(*(addr_t *)guest_cr3));
+ /*
+ if (cached == -1) {
+ PrintError("CR3 Cache failed\n");
return -1;
+ } else if (cached == 0) {
+ addr_t shadow_pt;
+
+ PrintDebug("New CR3 is different - flushing shadow page table %p\n", shadow_cr3 );
+ delete_page_tables_32(CR3_TO_PDE32_VA(*(uint_t*)shadow_cr3));
+
+ shadow_pt = v3_create_new_shadow_pt();
+
+ shadow_cr3->pml4t_base_addr = (addr_t)V3_PAddr((void *)(addr_t)PAGE_BASE_ADDR(shadow_pt));
+ PrintDebug( "Created new shadow page table %p\n", (void *)(addr_t)shadow_cr3->pml4t_base_addr );
+ } else {
+ PrintDebug("Reusing cached shadow Page table\n");
}
+
+ shadow_cr3->pwt = guest_cr3->pwt;
+ shadow_cr3->pcd = guest_cr3->pcd;
+
+ return 0;
+ */
+}
- shadow_pde = (pde32_t *)(CR3_TO_PDE32(state->shadow_cr3.e_reg.low));
- if (host_pa_to_host_va(CR3_TO_PDE32(state->guest_cr3.e_reg.low), (addr_t*)&guest_pde) != 0) {
+// Reads the guest CR3 register
+// creates new shadow page tables
+// updates the shadow CR3 register to point to the new pts
+int v3_activate_shadow_pt(struct guest_info * info) {
+ switch (info->cpu_mode) {
+
+ case PROTECTED:
+ return activate_shadow_pt_32(info);
+ case PROTECTED_PAE:
+ return activate_shadow_pt_32pae(info);
+ case LONG:
+ case LONG_32_COMPAT:
+ case LONG_16_COMPAT:
+ return activate_shadow_pt_64(info);
+ default:
+ PrintError("Invalid CPU mode: %d\n", info->cpu_mode);
return -1;
}
- // Delete the current page table
- delete_page_tables_pde32(shadow_pde);
+ return 0;
+}
+
- shadow_pde = os_hooks->allocate_pages(1);
+int v3_activate_passthrough_pt(struct guest_info * info) {
+ // For now... But we need to change this....
+ // As soon as shadow paging becomes active the passthrough tables are hosed
+ // So this will cause chaos if it is called at that time
- state->shadow_cr3.e_reg.low = (addr_t)shadow_pde;
+ info->ctrl_regs.cr3 = *(addr_t*)&(info->direct_map_pt);
+ //PrintError("Activate Passthrough Page tables not implemented\n");
+ return 0;
+}
- state->shadow_mode = PDE32;
- for (i = 0; i < MAX_PDE32_ENTRIES; i++) {
- shadow_pde[i] = guest_pde[i];
- // The shadow can be identical to the guest if it's not present
- if (!shadow_pde[i].present) {
- continue;
+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
+
+#ifdef DEBUG_SHADOW_PAGING
+ PrintHostPageTree(info->cpu_mode, fault_addr, info->ctrl_regs.cr3);
+ PrintGuestPageTree(info, fault_addr, info->shdw_pg_state.guest_cr3);
+#endif
+
+ return handle_special_page_fault(info, fault_addr, fault_addr, error_code);
+ } else if (info->mem_mode == VIRTUAL_MEM) {
+
+ switch (info->cpu_mode) {
+ case PROTECTED:
+ return handle_shadow_pagefault_32(info, fault_addr, error_code);
+ break;
+ case PROTECTED_PAE:
+ return handle_shadow_pagefault_32pae(info, fault_addr, error_code);
+ case LONG:
+ return handle_shadow_pagefault_64(info, fault_addr, error_code);
+ break;
+ default:
+ PrintError("Unhandled CPU Mode\n");
+ return -1;
}
+ } else {
+ PrintError("Invalid Memory mode\n");
+ return -1;
+ }
+}
+
+addr_t v3_create_new_shadow_pt() {
+ void * host_pde = 0;
- if (shadow_pde[i].large_pages) {
- // large page - just map it through shadow map to generate its physical location
- addr_t guest_addr = PAGE_ADDR(shadow_pde[i].pt_base_addr);
- addr_t host_addr;
- shadow_region_t * ent;
+ host_pde = V3_VAddr(V3_AllocPages(1));
+ memset(host_pde, 0, PAGE_SIZE);
+
+ return (addr_t)host_pde;
+}
+
+
+static void inject_guest_pf(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
+ if (info->enable_profiler) {
+ info->profiler.guest_pf_cnt++;
+ }
+
+ info->ctrl_regs.cr2 = fault_addr;
+ v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code);
+}
+
+
+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
+ 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_access != PT_ACCESS_OK) {
+ // Guest Access Error
+
+ if ((shadow_access != PT_ACCESS_NOT_PRESENT) &&
+ (guest_access != PT_ACCESS_NOT_PRESENT)) {
+ // aka (guest permission error)
+ return 1;
+ }
+
+ if ((shadow_access == PT_ACCESS_NOT_PRESENT) &&
+ (guest_access == PT_ACCESS_NOT_PRESENT)) {
+ // Page tables completely blank, handle guest first
+ return 1;
+ }
+
+ // Otherwise we'll handle the guest fault later...?
+ }
- ent = get_shadow_region_by_addr(&(guest_info->mem_map), guest_addr);
+ return 0;
+}
+
+
+
+
+/*
+ * *
+ * *
+ * * 64 bit Page table fault handlers
+ * *
+ * *
+ */
+
+static int handle_shadow_pagefault_64(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
+ pt_access_status_t guest_access;
+ pt_access_status_t shadow_access;
+ int ret;
+ PrintDebug("64 bit shadow page fault\n");
+
+ ret = v3_check_guest_pt_32(info, info->shdw_pg_state.guest_cr3, fault_addr, error_code, &guest_access);
+
+ PrintDebug("Guest Access Check: %d (access=%d)\n", ret, guest_access);
+
+ ret = v3_check_host_pt_32(info->ctrl_regs.cr3, fault_addr, error_code, &shadow_access);
+
+ PrintDebug("Shadow Access Check: %d (access=%d)\n", ret, shadow_access);
+
+
+ PrintError("64 bit shadow paging not implemented\n");
+ return -1;
+}
+
+
+/*
+ * *
+ * *
+ * * 32 bit PAE Page table fault handlers
+ * *
+ * *
+ */
+
+static int handle_shadow_pagefault_32pae(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
+ PrintError("32 bit PAE shadow paging not implemented\n");
+ return -1;
+}
+
+
+
+
+
+
+
+/*
+ * *
+ * *
+ * * 32 bit Page table fault handlers
+ * *
+ * *
+ */
+static int handle_large_pagefault_32(struct guest_info * info,
+ addr_t fault_addr, pf_error_t error_code,
+ pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde);
+
+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);
+
+
+static int handle_shadow_pagefault_32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
+ pde32_t * guest_pd = NULL;
+ pde32_t * shadow_pd = CR3_TO_PDE32_VA(info->ctrl_regs.cr3);
+ addr_t guest_cr3 = CR3_TO_PDE32_PA(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: %p\n", (void*) fault_addr );
+
+ 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)]);
+
+
+ // Check the guest page permissions
+ guest_pde_access = v3_can_access_pde32(guest_pd, fault_addr, error_code);
+
+ // Check the shadow page permissions
+ shadow_pde_access = v3_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",
+ *(uint_t *)&guest_pde_access, *(uint_t *)&error_code);
+ inject_guest_pf(info, fault_addr, error_code);
+ return 0;
+ }
+
+
+ if (shadow_pde_access == PT_ACCESS_NOT_PRESENT)
+ {
+ pte32_t * shadow_pt = (pte32_t *)v3_create_new_shadow_pt();
+
+ 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;
- if (!ent) {
- // FIXME Panic here - guest is trying to map to physical memory
- // it does not own in any way!
- return -1;
- }
- // FIXME Bounds check here to see if it's trying to trick us
+ // VMM Specific options
+ shadow_pde->write_through = 0;
+ shadow_pde->cache_disable = 0;
+ shadow_pde->global_page = 0;
+ //
- switch (ent->host_type) {
- case HOST_REGION_PHYSICAL_MEMORY:
- // points into currently allocated physical memory, so we just
- // set up the shadow to point to the mapped location
- if (guest_pa_to_host_pa(guest_info, guest_addr, &host_addr)) {
- // Panic here
- return -1;
+ guest_pde->accessed = 1;
+
+ shadow_pde->pt_base_addr = PAGE_BASE_ADDR((addr_t)V3_PAddr(shadow_pt));
+
+ if (guest_pde->large_page == 0) {
+ pte32_t * guest_pt = NULL;
+ shadow_pde->writable = guest_pde->writable;
+
+ if (guest_pa_to_host_va(info, BASE_TO_PAGE_ADDR(guest_pde->pt_base_addr), (addr_t*)&guest_pt) == -1) {
+ // Machine check the guest
+ PrintDebug("Invalid Guest PTE Address: 0x%p\n", (void *)BASE_TO_PAGE_ADDR(guest_pde->pt_base_addr));
+ v3_raise_exception(info, MC_EXCEPTION);
+ return 0;
}
- shadow_pde[i].pt_base_addr = PAGE_ALIGNED_ADDR(host_addr);
- // FIXME set vmm_info bits here
- break;
- case HOST_REGION_UNALLOCATED:
- // points to physical memory that is *allowed* but that we
- // have not yet allocated. We mark as not present and set a
- // bit to remind us to allocate it later
- shadow_pde[i].present = 0;
- // FIXME Set vminfo bits here so that we know that we will be
- // allocating it later
- break;
- case HOST_REGION_NOTHING:
- // points to physical memory that is NOT ALLOWED.
- // We will mark it as not present and set a bit to remind
- // us that it's bad later and insert a GPF then
- shadow_pde[i].present = 0;
- break;
- case HOST_REGION_MEMORY_MAPPED_DEVICE:
- case HOST_REGION_REMOTE:
- case HOST_REGION_SWAPPED:
- default:
- // Panic. Currently unhandled
- return -1;
- break;
+ 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 {
+ // ?? What if guest pde is dirty a this point?
+ ((pde32_4MB_t *)guest_pde)->dirty = 0;
+ shadow_pde->writable = 0;
}
- } else {
- pte32_t * guest_pte;
- pte32_t * shadow_pte;
- addr_t guest_addr;
- addr_t guest_pte_host_addr;
- shadow_region_t * ent;
+ }
+ else if (shadow_pde_access == PT_ACCESS_OK)
+ {
+ //
+ // PTE fault
+ //
+ pte32_t * shadow_pt = (pte32_t *)V3_VAddr( (void*)(addr_t) BASE_TO_PAGE_ADDR(shadow_pde->pt_base_addr) );
+
+ if (guest_pde->large_page == 0) {
+ pte32_t * guest_pt = NULL;
+
+ if (guest_pa_to_host_va(info, BASE_TO_PAGE_ADDR(guest_pde->pt_base_addr), (addr_t*)&guest_pt) == -1) {
+ // Machine check the guest
+ PrintDebug("Invalid Guest PTE Address: 0x%p\n", (void *)BASE_TO_PAGE_ADDR(guest_pde->pt_base_addr));
+ v3_raise_exception(info, MC_EXCEPTION);
+ return 0;
+ }
+
+ 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_pagefault_32(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_ACCESS_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
+ //
+
+ 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_ACCESS_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);
+ PrintPTEntry(PAGE_PD32, fault_addr, guest_pde);
+ PrintDebug("Shadow PDE: (access=%d)\n\t", shadow_pde_access);
+ PrintPTEntry(PAGE_PD32, fault_addr, shadow_pde);
+#endif
+
+ return 0;
+ }
+
+ PrintDebug("Returning end of PDE function (rip=%p)\n", (void *)(addr_t)(info->rip));
+ return 0;
+}
- // small page - set PDE and follow down to the child table
- shadow_pde[i] = guest_pde[i];
- guest_addr = PAGE_ADDR(guest_pde[i].pt_base_addr);
- // Allocate a new second level page table for the shadow
- shadow_pte = os_hooks->allocate_pages(1);
+/* The guest status checks have already been done,
+ * only special case shadow checks remain
+ */
+static int handle_large_pagefault_32(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 = 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);
- // make our first level page table in the shadow point to it
- shadow_pde[i].pt_base_addr = PAGE_ALIGNED_ADDR(shadow_pte);
-
- ent = get_shadow_region_by_addr(&(guest_info->mem_map), guest_addr);
-
+ struct v3_shadow_region * shdw_reg = v3_get_shadow_region(info, guest_fault_pa);
- /* JRL: This is bad.... */
- // For now the guest Page Table must always be mapped to host physical memory
- /* If we swap out a page table or if it isn't present for some reason, this turns real ugly */
+
+ if ((shdw_reg == NULL) ||
+ (shdw_reg->host_type == SHDW_REGION_INVALID)) {
+ // Inject a machine check in the guest
+ PrintDebug("Invalid Guest Address in page table (0x%p)\n", (void *)guest_fault_pa);
+ v3_raise_exception(info, MC_EXCEPTION);
+ return -1;
+ }
+
+ 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_ACCESS_NOT_PRESENT) {
+ // Get the guest physical address of the fault
+
+ if ((shdw_reg->host_type == SHDW_REGION_ALLOCATED) ||
+ (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK)) {
+ struct shadow_page_state * state = &(info->shdw_pg_state);
+ addr_t shadow_pa = v3_get_shadow_addr(shdw_reg, guest_fault_pa);
+
+ shadow_pte->page_base_addr = PAGE_BASE_ADDR(shadow_pa);
+
+ shadow_pte->present = 1;
+
+ /* 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;
+
+ 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->vmm_info = PT32_GUEST_PT;
+ shadow_pte->writable = 0;
+ } else if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
+ shadow_pte->writable = 0;
+ } else {
+ shadow_pte->writable = 1;
+ }
+
+ //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) {
- if ((!ent) || (ent->host_type != HOST_REGION_PHYSICAL_MEMORY)) {
- // FIXME Panic here - guest is trying to map to physical memory
- // it does not own in any way!
+ if (v3_handle_mem_full_hook(info, fault_addr, guest_fault_pa, shdw_reg, 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_ACCESS_WRITE_ERROR) {
+
+ if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
- // Address of the relevant second level page table in the guest
- if (guest_pa_to_host_pa(guest_info, guest_addr, &guest_pte_host_addr)) {
- // Panic here
+ if (v3_handle_mem_wr_hook(info, fault_addr, guest_fault_pa, shdw_reg, error_code) == -1) {
+ PrintError("Special Page Fault handler returned error for address: %p\n", (void *)fault_addr);
return -1;
}
+ } else 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 (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;
+ }
- // host_addr now contains the host physical address for the guest's 2nd level page table
- // Now we transform it to relevant virtual address
- guest_pte = os_hooks->paddr_to_vaddr((void *)guest_pte_host_addr);
+ PrintDebug("Returning from large page fault handler\n");
+ return 0;
+}
- // Now we walk through the second level guest page table
- // and clone it into the shadow
- for (j = 0; j < MAX_PTE32_ENTRIES; j++) {
- shadow_pte[j] = guest_pte[j];
- addr_t guest_addr = PAGE_ADDR(shadow_pte[j].page_base_addr);
-
- shadow_region_t * ent;
- ent = get_shadow_region_by_addr(&(guest_info->mem_map), guest_addr);
+
+/*
+ * 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) {
+
+ pt_access_status_t guest_pte_access;
+ pt_access_status_t shadow_pte_access;
+ 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 v3_shadow_region * shdw_reg = v3_get_shadow_region(info, guest_pa);
+
+ if ((shdw_reg == NULL) ||
+ (shdw_reg->host_type == SHDW_REGION_INVALID)) {
+ // Inject a machine check in the guest
+ PrintDebug("Invalid Guest Address in page table (0x%p)\n", (void *)guest_pa);
+ v3_raise_exception(info, MC_EXCEPTION);
+ return 0;
+ }
+
+ // Check the guest page permissions
+ guest_pte_access = v3_can_access_pte32(guest_pt, fault_addr, error_code);
+
+ // Check the shadow page permissions
+ shadow_pte_access = v3_can_access_pte32(shadow_pt, fault_addr, error_code);
+
+#ifdef DEBUG_SHADOW_PAGING
+ PrintDebug("Guest PTE: (access=%d)\n\t", guest_pte_access);
+ PrintPTEntry(PAGE_PT32, fault_addr, guest_pte);
+ PrintDebug("Shadow PTE: (access=%d)\n\t", shadow_pte_access);
+ PrintPTEntry(PAGE_PT32, fault_addr, shadow_pte);
+#endif
+
+ /* 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;
+ }
+
+
+ if (shadow_pte_access == PT_ACCESS_NOT_PRESENT) {
+ // Page Table Entry Not Present
+ PrintDebug("guest_pa =%p\n", (void *)guest_pa);
+
+ if ((shdw_reg->host_type == SHDW_REGION_ALLOCATED) ||
+ (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK)) {
+ struct shadow_page_state * state = &(info->shdw_pg_state);
+ addr_t shadow_pa = v3_get_shadow_addr(shdw_reg, guest_pa);
- if (!ent) {
- // FIXME Panic here - guest is trying to map to physical memory
- // it does not own in any way!
- return -1;
- }
+ shadow_pte->page_base_addr = PAGE_BASE_ADDR(shadow_pa);
+
+ shadow_pte->present = guest_pte->present;
+ shadow_pte->user_page = guest_pte->user_page;
+
+ //set according to VMM policy
+ shadow_pte->write_through = 0;
+ shadow_pte->cache_disable = 0;
+ shadow_pte->global_page = 0;
+ //
+
+ guest_pte->accessed = 1;
+
+ if (find_pte_map(state->cached_ptes, PAGE_ADDR(guest_pa)) != NULL) {
+ // Check if the entry is a page table...
+ PrintDebug("Marking page as Guest Page Table %d\n", shadow_pte->writable);
+ shadow_pte->vmm_info = PT32_GUEST_PT;
+ }
- switch (ent->host_type) {
- case HOST_REGION_PHYSICAL_MEMORY:
- {
- addr_t host_addr;
-
- // points into currently allocated physical memory, so we just
- // set up the shadow to point to the mapped location
- if (guest_pa_to_host_pa(guest_info, guest_addr, &host_addr)) {
- // Panic here
- return -1;
- }
-
- shadow_pte[j].page_base_addr = PAGE_ALIGNED_ADDR(host_addr);
- // FIXME set vmm_info bits here
- break;
- }
- case HOST_REGION_UNALLOCATED:
- // points to physical memory that is *allowed* but that we
- // have not yet allocated. We mark as not present and set a
- // bit to remind us to allocate it later
- shadow_pte[j].present = 0;
- // FIXME Set vminfo bits here so that we know that we will be
- // allocating it later
- break;
- case HOST_REGION_NOTHING:
- // points to physical memory that is NOT ALLOWED.
- // We will mark it as not present and set a bit to remind
- // us that it's bad later and insert a GPF then
- shadow_pte[j].present = 0;
- break;
- case HOST_REGION_MEMORY_MAPPED_DEVICE:
- case HOST_REGION_REMOTE:
- case HOST_REGION_SWAPPED:
- default:
- // Panic. Currently unhandled
- return -1;
- break;
+ if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
+ shadow_pte->writable = 0;
+ } else 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;
+
+ 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 (v3_handle_mem_full_hook(info, fault_addr, guest_pa, shdw_reg, 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_ACCESS_WRITE_ERROR) &&
+ (guest_pte->dirty == 0)) {
+ */
+ } else if (shadow_pte_access == PT_ACCESS_WRITE_ERROR) {
+ guest_pte->dirty = 1;
+
+ if (shdw_reg->host_type == SHDW_REGION_WRITE_HOOK) {
+ if (v3_handle_mem_wr_hook(info, fault_addr, guest_pa, shdw_reg, error_code) == -1) {
+ PrintError("Special Page fault handler returned error for address: %p\n", (void *)fault_addr);
+ return -1;
}
+ } else {
+ PrintDebug("Shadow PTE Write Error\n");
+ 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
+ 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;
}
+
+ PrintDebug("Returning end of function\n");
return 0;
}
+
+
+
+
+
+
+/* Currently Does not work with Segmentation!!! */
+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
+ PrintError("ERROR: INVLPG called in non paged mode\n");
+ return -1;
+ }
+
+
+ if (info->cpu_mode != PROTECTED) {
+ PrintError("Unsupported CPU mode (mode=%s)\n", v3_cpu_mode_to_str(info->cpu_mode));
+ return -1;
+ }
+
+ uchar_t instr[15];
+ int index = 0;
+
+ int 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%p (ret=%d)\n", (void *)(addr_t)(info->rip), ret);
+ return -1;
+ }
+
+
+ /* Can INVLPG work with Segments?? */
+ while (is_prefix_byte(instr[index])) {
+ index++;
+ }
+
+
+ if( (instr[index + 0] != (uchar_t) 0x0f) ||
+ (instr[index + 1] != (uchar_t) 0x01) ) {
+ PrintError("invalid Instruction Opcode\n");
+ PrintTraceMemDump(instr, 15);
+ return -1;
+ }
+
+ addr_t first_operand;
+ addr_t second_operand;
+ addr_t guest_cr3 = CR3_TO_PDE32_PA(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%p\n", (void *)guest_cr3);
+ return -1;
+ }
+
+ index += 2;
+
+ v3_operand_type_t addr_type = decode_operands32(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG32);
+
+ if (addr_type != MEM_OPERAND) {
+ PrintError("Invalid Operand type\n");
+ return -1;
+ }
+
+ pde32_t * shadow_pd = (pde32_t *)CR3_TO_PDE32_VA(info->ctrl_regs.cr3);
+ pde32_t * shadow_pde = (pde32_t *)&shadow_pd[PDE32_INDEX(first_operand)];
+ pde32_t * guest_pde;
+
+ //PrintDebug("PDE Index=%d\n", PDE32_INDEX(first_operand));
+ //PrintDebug("FirstOperand = %x\n", first_operand);
+
+ PrintDebug("Invalidating page for %p\n", (void *)first_operand);
+
+ guest_pde = (pde32_t *)&(guest_pd[PDE32_INDEX(first_operand)]);
+
+ if (guest_pde->large_page == 1) {
+ shadow_pde->present = 0;
+ PrintDebug("Invalidating Large Page\n");
+ } else
+ if (shadow_pde->present == 1) {
+ pte32_t * shadow_pt = (pte32_t *)(addr_t)BASE_TO_PAGE_ADDR(shadow_pde->pt_base_addr);
+ pte32_t * shadow_pte = (pte32_t *) V3_VAddr( (void*) &shadow_pt[PTE32_INDEX(first_operand)] );
+
+#ifdef DEBUG_SHADOW_PAGING
+ PrintDebug("Setting not present\n");
+ PrintPTEntry(PAGE_PT32, first_operand, shadow_pte);
+#endif
+ shadow_pte->present = 0;
+ }
+
+ info->rip += index;
+
+ return 0;
+}
+
