2 * This file is part of the Palacios Virtual Machine Monitor developed
3 * by the V3VEE Project with funding from the United States National
4 * Science Foundation and the Department of Energy.
6 * The V3VEE Project is a joint project between Northwestern University
7 * and the University of New Mexico. You can find out more at
10 * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu>
11 * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org>
12 * All rights reserved.
14 * Author: Jack Lange <jarusl@cs.northwestern.edu>
16 * This is free software. You are permitted to use,
17 * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
21 #include <palacios/vmm_shadow_paging.h>
24 #include <palacios/vmm.h>
25 #include <palacios/vm_guest_mem.h>
26 #include <palacios/vmm_decoder.h>
27 #include <palacios/vmm_ctrl_regs.h>
29 #include <palacios/vmm_hashtable.h>
31 #include <palacios/vmm_direct_paging.h>
33 #ifndef DEBUG_SHADOW_PAGING
35 #define PrintDebug(fmt, args...)
44 struct shadow_page_data {
48 struct list_head page_list_node;
53 static struct shadow_page_data * create_new_shadow_pt(struct guest_info * info);
54 static int inject_guest_pf(struct guest_info * info, addr_t fault_addr, pf_error_t error_code);
55 static int is_guest_pf(pt_access_status_t guest_access, pt_access_status_t shadow_access);
58 #include "vmm_shadow_paging_32.h"
59 #include "vmm_shadow_paging_32pae.h"
60 #include "vmm_shadow_paging_64.h"
64 int v3_init_shadow_page_state(struct guest_info * info) {
65 struct shadow_page_state * state = &(info->shdw_pg_state);
69 state->guest_efer.value = 0x0LL;
71 INIT_LIST_HEAD(&(state->page_list));
78 // Reads the guest CR3 register
79 // creates new shadow page tables
80 // updates the shadow CR3 register to point to the new pts
81 int v3_activate_shadow_pt(struct guest_info * info) {
82 switch (v3_get_vm_cpu_mode(info)) {
85 return activate_shadow_pt_32(info);
87 return activate_shadow_pt_32pae(info);
91 return activate_shadow_pt_64(info);
93 PrintError("Invalid CPU mode: %s\n", v3_cpu_mode_to_str(v3_get_vm_cpu_mode(info)));
102 // This must flush any caches
103 // and reset the cr3 value to the correct value
104 int v3_invalidate_shadow_pts(struct guest_info * info) {
105 return v3_activate_shadow_pt(info);
109 int v3_handle_shadow_pagefault(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
111 if (v3_get_vm_mem_mode(info) == PHYSICAL_MEM) {
112 // If paging is not turned on we need to handle the special cases
113 return v3_handle_passthrough_pagefault(info, fault_addr, error_code);
114 } else if (v3_get_vm_mem_mode(info) == VIRTUAL_MEM) {
116 switch (v3_get_vm_cpu_mode(info)) {
118 return handle_shadow_pagefault_32(info, fault_addr, error_code);
121 return handle_shadow_pagefault_32pae(info, fault_addr, error_code);
125 return handle_shadow_pagefault_64(info, fault_addr, error_code);
128 PrintError("Unhandled CPU Mode: %s\n", v3_cpu_mode_to_str(v3_get_vm_cpu_mode(info)));
132 PrintError("Invalid Memory mode\n");
138 int v3_handle_shadow_invlpg(struct guest_info * info) {
140 struct x86_instr dec_instr;
144 if (v3_get_vm_mem_mode(info) != VIRTUAL_MEM) {
145 // Paging must be turned on...
146 // should handle with some sort of fault I think
147 PrintError("ERROR: INVLPG called in non paged mode\n");
151 if (v3_get_vm_mem_mode(info) == PHYSICAL_MEM) {
152 ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
154 ret = read_guest_va_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
158 PrintError("Could not read instruction into buffer\n");
162 if (v3_decode(info, (addr_t)instr, &dec_instr) == -1) {
163 PrintError("Decoding Error\n");
167 if ((dec_instr.op_type != V3_OP_INVLPG) ||
168 (dec_instr.num_operands != 1) ||
169 (dec_instr.dst_operand.type != MEM_OPERAND)) {
170 PrintError("Decoder Error: Not a valid INVLPG instruction...\n");
174 vaddr = dec_instr.dst_operand.operand;
176 info->rip += dec_instr.instr_length;
178 switch (v3_get_vm_cpu_mode(info)) {
180 return handle_shadow_invlpg_32(info, vaddr);
182 return handle_shadow_invlpg_32pae(info, vaddr);
186 return handle_shadow_invlpg_64(info, vaddr);
188 PrintError("Invalid CPU mode: %s\n", v3_cpu_mode_to_str(v3_get_vm_cpu_mode(info)));
196 static struct shadow_page_data * create_new_shadow_pt(struct guest_info * info) {
197 struct shadow_page_state * state = &(info->shdw_pg_state);
198 v3_reg_t cur_cr3 = info->ctrl_regs.cr3;
199 struct shadow_page_data * page_tail = NULL;
200 addr_t shdw_page = 0;
202 if (!list_empty(&(state->page_list))) {
203 page_tail = list_tail_entry(&(state->page_list), struct shadow_page_data, page_list_node);
205 if (page_tail->cr3 != cur_cr3) {
206 PrintDebug("Reusing old shadow Page: %p (cur_CR3=%p)(page_cr3=%p) \n",
207 (void *)(addr_t)page_tail->page_pa,
208 (void *)(addr_t)cur_cr3,
209 (void *)(addr_t)(page_tail->cr3));
211 list_move(&(page_tail->page_list_node), &(state->page_list));
213 memset(V3_VAddr((void *)(page_tail->page_pa)), 0, PAGE_SIZE_4KB);
222 page_tail = (struct shadow_page_data *)V3_Malloc(sizeof(struct shadow_page_data));
223 page_tail->page_pa = (addr_t)V3_AllocPages(1);
225 PrintDebug("Allocating new shadow Page: %p (cur_cr3=%p)\n",
226 (void *)(addr_t)page_tail->page_pa,
227 (void *)(addr_t)cur_cr3);
229 page_tail->cr3 = cur_cr3;
230 list_add(&(page_tail->page_list_node), &(state->page_list));
232 shdw_page = (addr_t)V3_VAddr((void *)(page_tail->page_pa));
233 memset((void *)shdw_page, 0, PAGE_SIZE_4KB);
239 static int inject_guest_pf(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
240 if (info->enable_profiler) {
241 info->profiler.guest_pf_cnt++;
244 info->ctrl_regs.cr2 = fault_addr;
245 return v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code);
249 static int is_guest_pf(pt_access_status_t guest_access, pt_access_status_t shadow_access) {
250 /* basically the reasoning is that there can be multiple reasons for a page fault:
251 If there is a permissions failure for a page present in the guest _BUT_
252 the reason for the fault was that the page is not present in the shadow,
253 _THEN_ we have to map the shadow page in and reexecute, this will generate
254 a permissions fault which is _THEN_ valid to send to the guest
255 _UNLESS_ both the guest and shadow have marked the page as not present
259 if (guest_access != PT_ACCESS_OK) {
260 // Guest Access Error
262 if ((shadow_access != PT_ACCESS_NOT_PRESENT) &&
263 (guest_access != PT_ACCESS_NOT_PRESENT)) {
264 // aka (guest permission error)
268 if ((shadow_access == PT_ACCESS_NOT_PRESENT) &&
269 (guest_access == PT_ACCESS_NOT_PRESENT)) {
270 // Page tables completely blank, handle guest first
274 // Otherwise we'll handle the guest fault later...?