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 void 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);
70 INIT_LIST_HEAD(&(state->page_list));
77 // Reads the guest CR3 register
78 // creates new shadow page tables
79 // updates the shadow CR3 register to point to the new pts
80 int v3_activate_shadow_pt(struct guest_info * info) {
81 switch (v3_get_cpu_mode(info)) {
84 return activate_shadow_pt_32(info);
86 return activate_shadow_pt_32pae(info);
90 return activate_shadow_pt_64(info);
92 PrintError("Invalid CPU mode: %s\n", v3_cpu_mode_to_str(v3_get_cpu_mode(info)));
101 // This must flush any caches
102 // and reset the cr3 value to the correct value
103 int v3_invalidate_shadow_pts(struct guest_info * info) {
104 return v3_activate_shadow_pt(info);
108 int v3_handle_shadow_pagefault(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
110 if (v3_get_mem_mode(info) == PHYSICAL_MEM) {
111 // If paging is not turned on we need to handle the special cases
112 return v3_handle_passthrough_pagefault(info, fault_addr, error_code);
113 } else if (v3_get_mem_mode(info) == VIRTUAL_MEM) {
115 switch (v3_get_cpu_mode(info)) {
117 return handle_shadow_pagefault_32(info, fault_addr, error_code);
120 return handle_shadow_pagefault_32pae(info, fault_addr, error_code);
124 return handle_shadow_pagefault_64(info, fault_addr, error_code);
127 PrintError("Unhandled CPU Mode: %s\n", v3_cpu_mode_to_str(v3_get_cpu_mode(info)));
131 PrintError("Invalid Memory mode\n");
137 int v3_handle_shadow_invlpg(struct guest_info * info) {
139 struct x86_instr dec_instr;
143 if (v3_get_mem_mode(info) != VIRTUAL_MEM) {
144 // Paging must be turned on...
145 // should handle with some sort of fault I think
146 PrintError("ERROR: INVLPG called in non paged mode\n");
150 if (v3_get_mem_mode(info) == PHYSICAL_MEM) {
151 ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
153 ret = read_guest_va_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
157 PrintError("Could not read instruction into buffer\n");
161 if (v3_decode(info, (addr_t)instr, &dec_instr) == -1) {
162 PrintError("Decoding Error\n");
166 if ((dec_instr.op_type != V3_OP_INVLPG) ||
167 (dec_instr.num_operands != 1) ||
168 (dec_instr.dst_operand.type != MEM_OPERAND)) {
169 PrintError("Decoder Error: Not a valid INVLPG instruction...\n");
173 vaddr = dec_instr.dst_operand.operand;
175 info->rip += dec_instr.instr_length;
177 switch (v3_get_cpu_mode(info)) {
179 return handle_shadow_invlpg_32(info, vaddr);
181 return handle_shadow_invlpg_32pae(info, vaddr);
185 return handle_shadow_invlpg_64(info, vaddr);
187 PrintError("Invalid CPU mode: %s\n", v3_cpu_mode_to_str(v3_get_cpu_mode(info)));
195 static struct shadow_page_data * create_new_shadow_pt(struct guest_info * info) {
196 struct shadow_page_state * state = &(info->shdw_pg_state);
197 v3_reg_t cur_cr3 = info->ctrl_regs.cr3;
198 struct shadow_page_data * page_tail = NULL;
199 addr_t shdw_page = 0;
201 if (!list_empty(&(state->page_list))) {
202 page_tail = list_tail_entry(&(state->page_list), struct shadow_page_data, page_list_node);
204 if (page_tail->cr3 != cur_cr3) {
205 PrintDebug("Reusing old shadow Page: %p (cur_CR3=%p)(page_cr3=%p) \n",
206 (void *)(addr_t)page_tail->page_pa,
207 (void *)(addr_t)cur_cr3,
208 (void *)(addr_t)(page_tail->cr3));
210 list_move(&(page_tail->page_list_node), &(state->page_list));
212 memset(V3_VAddr((void *)(page_tail->page_pa)), 0, PAGE_SIZE_4KB);
221 page_tail = (struct shadow_page_data *)V3_Malloc(sizeof(struct shadow_page_data));
222 page_tail->page_pa = (addr_t)V3_AllocPages(1);
224 PrintDebug("Allocating new shadow Page: %p (cur_cr3=%p)\n",
225 (void *)(addr_t)page_tail->page_pa,
226 (void *)(addr_t)cur_cr3);
228 page_tail->cr3 = cur_cr3;
229 list_add(&(page_tail->page_list_node), &(state->page_list));
231 shdw_page = (addr_t)V3_VAddr((void *)(page_tail->page_pa));
232 memset((void *)shdw_page, 0, PAGE_SIZE_4KB);
238 static void inject_guest_pf(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
239 if (info->enable_profiler) {
240 info->profiler.guest_pf_cnt++;
243 info->ctrl_regs.cr2 = fault_addr;
244 v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code);
248 static int is_guest_pf(pt_access_status_t guest_access, pt_access_status_t shadow_access) {
249 /* basically the reasoning is that there can be multiple reasons for a page fault:
250 If there is a permissions failure for a page present in the guest _BUT_
251 the reason for the fault was that the page is not present in the shadow,
252 _THEN_ we have to map the shadow page in and reexecute, this will generate
253 a permissions fault which is _THEN_ valid to send to the guest
254 _UNLESS_ both the guest and shadow have marked the page as not present
258 if (guest_access != PT_ACCESS_OK) {
259 // Guest Access Error
261 if ((shadow_access != PT_ACCESS_NOT_PRESENT) &&
262 (guest_access != PT_ACCESS_NOT_PRESENT)) {
263 // aka (guest permission error)
267 if ((shadow_access == PT_ACCESS_NOT_PRESENT) &&
268 (guest_access == PT_ACCESS_NOT_PRESENT)) {
269 // Page tables completely blank, handle guest first
273 // Otherwise we'll handle the guest fault later...?