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 #ifdef CONFIG_SYMBIOTIC_SWAP
34 #include <palacios/vmm_sym_swap.h>
37 #ifndef CONFIG_DEBUG_SHADOW_PAGING
39 #define PrintDebug(fmt, args...)
48 struct shadow_page_data {
52 struct list_head page_list_node;
57 static struct shadow_page_data * create_new_shadow_pt(struct guest_info * info);
58 static int inject_guest_pf(struct guest_info * info, addr_t fault_addr, pf_error_t error_code);
59 static int is_guest_pf(pt_access_status_t guest_access, pt_access_status_t shadow_access);
62 #include "vmm_shadow_paging_32.h"
63 #include "vmm_shadow_paging_32pae.h"
64 #include "vmm_shadow_paging_64.h"
68 int v3_init_shadow_page_state(struct guest_info * info) {
69 struct shadow_page_state * state = &(info->shdw_pg_state);
73 state->guest_efer.value = 0x0LL;
75 INIT_LIST_HEAD(&(state->page_list));
82 // Reads the guest CR3 register
83 // creates new shadow page tables
84 // updates the shadow CR3 register to point to the new pts
85 int v3_activate_shadow_pt(struct guest_info * info) {
86 switch (v3_get_vm_cpu_mode(info)) {
89 return activate_shadow_pt_32(info);
91 return activate_shadow_pt_32pae(info);
95 return activate_shadow_pt_64(info);
97 PrintError("Invalid CPU mode: %s\n", v3_cpu_mode_to_str(v3_get_vm_cpu_mode(info)));
106 // This must flush any caches
107 // and reset the cr3 value to the correct value
108 int v3_invalidate_shadow_pts(struct guest_info * info) {
109 return v3_activate_shadow_pt(info);
113 int v3_handle_shadow_pagefault(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
115 if (v3_get_vm_mem_mode(info) == PHYSICAL_MEM) {
116 // If paging is not turned on we need to handle the special cases
117 return v3_handle_passthrough_pagefault(info, fault_addr, error_code);
118 } else if (v3_get_vm_mem_mode(info) == VIRTUAL_MEM) {
120 switch (v3_get_vm_cpu_mode(info)) {
122 return handle_shadow_pagefault_32(info, fault_addr, error_code);
125 return handle_shadow_pagefault_32pae(info, fault_addr, error_code);
129 return handle_shadow_pagefault_64(info, fault_addr, error_code);
132 PrintError("Unhandled CPU Mode: %s\n", v3_cpu_mode_to_str(v3_get_vm_cpu_mode(info)));
136 PrintError("Invalid Memory mode\n");
142 int v3_handle_shadow_invlpg(struct guest_info * info) {
144 struct x86_instr dec_instr;
148 if (v3_get_vm_mem_mode(info) != VIRTUAL_MEM) {
149 // Paging must be turned on...
150 // should handle with some sort of fault I think
151 PrintError("ERROR: INVLPG called in non paged mode\n");
155 if (v3_get_vm_mem_mode(info) == PHYSICAL_MEM) {
156 ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
158 ret = read_guest_va_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
162 PrintError("Could not read instruction into buffer\n");
166 if (v3_decode(info, (addr_t)instr, &dec_instr) == -1) {
167 PrintError("Decoding Error\n");
171 if ((dec_instr.op_type != V3_OP_INVLPG) ||
172 (dec_instr.num_operands != 1) ||
173 (dec_instr.dst_operand.type != MEM_OPERAND)) {
174 PrintError("Decoder Error: Not a valid INVLPG instruction...\n");
178 vaddr = dec_instr.dst_operand.operand;
180 info->rip += dec_instr.instr_length;
182 switch (v3_get_vm_cpu_mode(info)) {
184 return handle_shadow_invlpg_32(info, vaddr);
186 return handle_shadow_invlpg_32pae(info, vaddr);
190 return handle_shadow_invlpg_64(info, vaddr);
192 PrintError("Invalid CPU mode: %s\n", v3_cpu_mode_to_str(v3_get_vm_cpu_mode(info)));
200 static struct shadow_page_data * create_new_shadow_pt(struct guest_info * info) {
201 struct shadow_page_state * state = &(info->shdw_pg_state);
202 v3_reg_t cur_cr3 = info->ctrl_regs.cr3;
203 struct shadow_page_data * page_tail = NULL;
204 addr_t shdw_page = 0;
206 if (!list_empty(&(state->page_list))) {
207 page_tail = list_tail_entry(&(state->page_list), struct shadow_page_data, page_list_node);
209 if (page_tail->cr3 != cur_cr3) {
210 PrintDebug("Reusing old shadow Page: %p (cur_CR3=%p)(page_cr3=%p) \n",
211 (void *)(addr_t)page_tail->page_pa,
212 (void *)(addr_t)cur_cr3,
213 (void *)(addr_t)(page_tail->cr3));
215 list_move(&(page_tail->page_list_node), &(state->page_list));
217 memset(V3_VAddr((void *)(page_tail->page_pa)), 0, PAGE_SIZE_4KB);
226 page_tail = (struct shadow_page_data *)V3_Malloc(sizeof(struct shadow_page_data));
227 page_tail->page_pa = (addr_t)V3_AllocPages(1);
229 PrintDebug("Allocating new shadow Page: %p (cur_cr3=%p)\n",
230 (void *)(addr_t)page_tail->page_pa,
231 (void *)(addr_t)cur_cr3);
233 page_tail->cr3 = cur_cr3;
234 list_add(&(page_tail->page_list_node), &(state->page_list));
236 shdw_page = (addr_t)V3_VAddr((void *)(page_tail->page_pa));
237 memset((void *)shdw_page, 0, PAGE_SIZE_4KB);
243 static int inject_guest_pf(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
245 #ifdef CONFIG_PROFILE_VMM
246 if (info->enable_profiler) {
247 info->profiler.guest_pf_cnt++;
251 info->ctrl_regs.cr2 = fault_addr;
253 return v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code);
257 static int is_guest_pf(pt_access_status_t guest_access, pt_access_status_t shadow_access) {
258 /* basically the reasoning is that there can be multiple reasons for a page fault:
259 If there is a permissions failure for a page present in the guest _BUT_
260 the reason for the fault was that the page is not present in the shadow,
261 _THEN_ we have to map the shadow page in and reexecute, this will generate
262 a permissions fault which is _THEN_ valid to send to the guest
263 _UNLESS_ both the guest and shadow have marked the page as not present
267 if (guest_access != PT_ACCESS_OK) {
268 // Guest Access Error
270 if ((shadow_access != PT_ACCESS_NOT_PRESENT) &&
271 (guest_access != PT_ACCESS_NOT_PRESENT)) {
272 // aka (guest permission error)
277 if ((shadow_access == PT_ACCESS_NOT_PRESENT) &&
278 (guest_access == PT_ACCESS_NOT_PRESENT)) {
279 // Page tables completely blank, handle guest first
284 if (guest_access == PT_ACCESS_NOT_PRESENT) {
285 // Page tables completely blank, handle guest first
289 // Otherwise we'll handle the guest fault later...?