X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?p=palacios.git;a=blobdiff_plain;f=palacios%2Fsrc%2Fpalacios%2Fvmm_shadow_paging.c;h=0afc383269000e456d57847a5cdfc6c5d86a1973;hp=57fade1b85509dae5e90c2bebf3988642f547423;hb=0e097100a26bc43eb8964734fa43130fc4c71429;hpb=2b1f4ef19d766727f873476861c64339c8836a40 diff --git a/palacios/src/palacios/vmm_shadow_paging.c b/palacios/src/palacios/vmm_shadow_paging.c index 57fade1..0afc383 100644 --- a/palacios/src/palacios/vmm_shadow_paging.c +++ b/palacios/src/palacios/vmm_shadow_paging.c @@ -1,147 +1,311 @@ +/* + * 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 + * Copyright (c) 2008, The V3VEE Project + * All rights reserved. + * + * Author: Jack Lange + * + * This is free software. You are permitted to use, + * redistribute, and modify it as specified in the file "V3VEE_LICENSE". + */ + + #include #include #include +#include +#include + +#include + +#include + + +#ifdef CONFIG_SHADOW_PAGING_TELEMETRY +#include +#endif + +#ifdef CONFIG_SYMBIOTIC_SWAP +#include +#endif -extern struct vmm_os_hooks * os_hooks; +#ifndef CONFIG_DEBUG_SHADOW_PAGING +#undef PrintDebug +#define PrintDebug(fmt, args...) +#endif -int init_shadow_page_state(struct shadow_page_state * state) { - state->guest_mode = PDE32; - state->shadow_mode = PDE32; +/*** + *** There be dragons + ***/ + + +struct shadow_page_data { + v3_reg_t cr3; + addr_t page_pa; - state->guest_cr3 = 0; - state->shadow_cr3 = 0; + struct list_head page_list_node; +}; - return 0; -} -int handle_shadow_pagefault(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) { - if (info->cpu_mode == PROTECTED_PG) { - return handle_shadow_pagefault32(info, fault_addr, error_code); - } else { - return -1; - } + +static struct shadow_page_data * create_new_shadow_pt(struct guest_info * info); +static int inject_guest_pf(struct guest_info * info, addr_t fault_addr, pf_error_t error_code); +static int is_guest_pf(pt_access_status_t guest_access, pt_access_status_t shadow_access); + + +#include "vmm_shadow_paging_32.h" +#include "vmm_shadow_paging_32pae.h" +#include "vmm_shadow_paging_64.h" + + + +#ifdef CONFIG_SHADOW_PAGING_TELEMETRY +static void telemetry_cb(struct guest_info * info, void * private_data, char * hdr) { + V3_Print("%s Guest Page faults: %d\n", hdr, info->shdw_pg_state.guest_faults); } +#endif -int handle_shadow_pagefault32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) { - pde32_t * guest_pde = NULL; - pde32_t * shadow_pde = (pde32_t *)CR3_TO_PDE32(info->shdw_pg_state.shadow_cr3); - addr_t guest_cr3 = CR3_TO_PDE32(info->shdw_pg_state.guest_cr3); - if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pde) == -1) { - return -1; - } +int v3_init_shadow_page_state(struct guest_info * info) { + struct shadow_page_state * state = &(info->shdw_pg_state); + + state->guest_cr3 = 0; + state->guest_cr0 = 0; + state->guest_efer.value = 0x0LL; - if (error_code.present == 0) { - // Faulted because page was not present... - if (shadow_pde[PDE32_INDEX(fault_addr)].present) { - - - } else { - return -1; - } - } - - // Checks: - // Shadow PDE - // Guest PDE - // Shadow PTE - // Guest PTE - // Mem Map + INIT_LIST_HEAD(&(state->page_list)); + +#ifdef CONFIG_SHADOW_PAGING_TELEMETRY + if (info->enable_telemetry) { + v3_add_telemetry_cb(info, telemetry_cb, NULL); + } +#endif - return -1; + return 0; } -addr_t create_new_shadow_pt32(struct guest_info * info) { - void * host_pde = 0; - V3_AllocPages(host_pde, 1); - memset(host_pde, 0, PAGE_SIZE); +// 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 (v3_get_vm_cpu_mode(info)) { + + 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: %s\n", v3_cpu_mode_to_str(v3_get_vm_cpu_mode(info))); + return -1; + } - return (addr_t)host_pde; + return 0; } +// This must flush any caches +// and reset the cr3 value to the correct value +int v3_invalidate_shadow_pts(struct guest_info * info) { + return v3_activate_shadow_pt(info); +} -addr_t setup_shadow_pt32(struct guest_info * info, addr_t virt_cr3) { - addr_t cr3_guest_addr = CR3_TO_PDE32(virt_cr3); - pde32_t * guest_pde; - pde32_t * host_pde = NULL; - int i; - - // Setup up guest_pde to point to the PageDir in host addr - if (guest_pa_to_host_va(info, cr3_guest_addr, (addr_t*)&guest_pde) == -1) { - return 0; - } + +int v3_handle_shadow_pagefault(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) { - V3_AllocPages(host_pde, 1); - memset(host_pde, 0, PAGE_SIZE); + if (v3_get_vm_mem_mode(info) == PHYSICAL_MEM) { + // If paging is not turned on we need to handle the special cases + return v3_handle_passthrough_pagefault(info, fault_addr, error_code); + } else if (v3_get_vm_mem_mode(info) == VIRTUAL_MEM) { + + switch (v3_get_vm_cpu_mode(info)) { + 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: + case LONG_32_COMPAT: + case LONG_16_COMPAT: + return handle_shadow_pagefault_64(info, fault_addr, error_code); + break; + default: + PrintError("Unhandled CPU Mode: %s\n", v3_cpu_mode_to_str(v3_get_vm_cpu_mode(info))); + return -1; + } + } else { + PrintError("Invalid Memory mode\n"); + return -1; + } +} - for (i = 0; i < MAX_PDE32_ENTRIES; i++) { - if (guest_pde[i].present == 1) { - addr_t pt_host_addr; - addr_t host_pte; - if (guest_pa_to_host_va(info, PDE32_T_ADDR(guest_pde[i]), &pt_host_addr) == -1) { - return 0; - } +int v3_handle_shadow_invlpg(struct guest_info * info) { + uchar_t instr[15]; + struct x86_instr dec_instr; + int ret = 0; + addr_t vaddr = 0; - if ((host_pte = setup_shadow_pte32(info, pt_host_addr)) == 0) { - return 0; - } + if (v3_get_vm_mem_mode(info) != 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; + } - host_pde[i].present = 1; - host_pde[i].pt_base_addr = PD32_BASE_ADDR(host_pte); + if (v3_get_vm_mem_mode(info) == PHYSICAL_MEM) { + ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr); + } else { + ret = read_guest_va_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr); + } - // - // Set Page DIR flags - // + if (ret == -1) { + PrintError("Could not read instruction into buffer\n"); + return -1; } - } - PrintDebugPageTables(host_pde); + if (v3_decode(info, (addr_t)instr, &dec_instr) == -1) { + PrintError("Decoding Error\n"); + return -1; + } + + if ((dec_instr.op_type != V3_OP_INVLPG) || + (dec_instr.num_operands != 1) || + (dec_instr.dst_operand.type != MEM_OPERAND)) { + PrintError("Decoder Error: Not a valid INVLPG instruction...\n"); + return -1; + } - return (addr_t)host_pde; + vaddr = dec_instr.dst_operand.operand; + + info->rip += dec_instr.instr_length; + + switch (v3_get_vm_cpu_mode(info)) { + case PROTECTED: + return handle_shadow_invlpg_32(info, vaddr); + case PROTECTED_PAE: + return handle_shadow_invlpg_32pae(info, vaddr); + case LONG: + case LONG_32_COMPAT: + case LONG_16_COMPAT: + return handle_shadow_invlpg_64(info, vaddr); + default: + PrintError("Invalid CPU mode: %s\n", v3_cpu_mode_to_str(v3_get_vm_cpu_mode(info))); + return -1; + } } -addr_t setup_shadow_pte32(struct guest_info * info, addr_t pt_host_addr) { - pte32_t * guest_pte = (pte32_t *)pt_host_addr; - pte32_t * host_pte = NULL; - int i; - V3_AllocPages(host_pte, 1); - memset(host_pte, 0, PAGE_SIZE); +static struct shadow_page_data * create_new_shadow_pt(struct guest_info * info) { + struct shadow_page_state * state = &(info->shdw_pg_state); + v3_reg_t cur_cr3 = info->ctrl_regs.cr3; + struct shadow_page_data * page_tail = NULL; + addr_t shdw_page = 0; - for (i = 0; i < MAX_PTE32_ENTRIES; i++) { - if (guest_pte[i].present == 1) { - addr_t guest_pa = PTE32_T_ADDR(guest_pte[i]); - shadow_mem_type_t page_type; - addr_t host_pa = 0; + if (!list_empty(&(state->page_list))) { + page_tail = list_tail_entry(&(state->page_list), struct shadow_page_data, page_list_node); + + if (page_tail->cr3 != cur_cr3) { + PrintDebug("Reusing old shadow Page: %p (cur_CR3=%p)(page_cr3=%p) \n", + (void *)(addr_t)page_tail->page_pa, + (void *)(addr_t)cur_cr3, + (void *)(addr_t)(page_tail->cr3)); - page_type = get_shadow_addr_type(info, guest_pa); + list_move(&(page_tail->page_list_node), &(state->page_list)); - if (page_type == HOST_REGION_PHYSICAL_MEMORY) { - host_pa = get_shadow_addr(info, guest_pa); - } else { - - // - // Setup various memory types - // - } + memset(V3_VAddr((void *)(page_tail->page_pa)), 0, PAGE_SIZE_4KB); - host_pte[i].page_base_addr = PT32_BASE_ADDR(host_pa); - host_pte[i].present = 1; + + return page_tail; + } } - } - return (addr_t)host_pte; + // else + + page_tail = (struct shadow_page_data *)V3_Malloc(sizeof(struct shadow_page_data)); + page_tail->page_pa = (addr_t)V3_AllocPages(1); + + PrintDebug("Allocating new shadow Page: %p (cur_cr3=%p)\n", + (void *)(addr_t)page_tail->page_pa, + (void *)(addr_t)cur_cr3); + + page_tail->cr3 = cur_cr3; + list_add(&(page_tail->page_list_node), &(state->page_list)); + + shdw_page = (addr_t)V3_VAddr((void *)(page_tail->page_pa)); + memset((void *)shdw_page, 0, PAGE_SIZE_4KB); + + return page_tail; +} + + +static int inject_guest_pf(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) { + info->ctrl_regs.cr2 = fault_addr; + +#ifdef CONFIG_SHADOW_PAGING_TELEMETRY + info->shdw_pg_state.guest_faults++; +#endif + + return 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; + } + */ + + if (guest_access == PT_ACCESS_NOT_PRESENT) { + // Page tables completely blank, handle guest first + return 1; + } + + // Otherwise we'll handle the guest fault later...? + } + + return 0; }