X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=blobdiff_plain;f=palacios%2Fsrc%2Fpalacios%2Fvmm_shadow_paging.c;h=d3e4c931b37c05a8144b237706b4bd2ca52a35d7;hb=ead1cdbf64d8f8ae39a52abd3c9fedd17ae0408d;hp=57fade1b85509dae5e90c2bebf3988642f547423;hpb=2b1f4ef19d766727f873476861c64339c8836a40;p=palacios.git diff --git a/palacios/src/palacios/vmm_shadow_paging.c b/palacios/src/palacios/vmm_shadow_paging.c index 57fade1..d3e4c93 100644 --- a/palacios/src/palacios/vmm_shadow_paging.c +++ b/palacios/src/palacios/vmm_shadow_paging.c @@ -1,147 +1,353 @@ +/* + * 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 -extern struct vmm_os_hooks * os_hooks; +#include +#include -int init_shadow_page_state(struct shadow_page_state * state) { - state->guest_mode = PDE32; - state->shadow_mode = PDE32; - - state->guest_cr3 = 0; - state->shadow_cr3 = 0; - return 0; + + +#ifdef V3_CONFIG_SHADOW_PAGING_TELEMETRY +#include +#endif + +#ifdef V3_CONFIG_SYMBIOTIC_SWAP +#include +#endif + +#ifndef V3_CONFIG_DEBUG_SHADOW_PAGING +#undef PrintDebug +#define PrintDebug(fmt, args...) +#endif + + +static const char default_strategy[] = "VTLB"; + + +static struct hashtable * master_shdw_pg_table = NULL; + +static uint_t shdw_pg_hash_fn(addr_t key) { + char * name = (char *)key; + return v3_hash_buffer((uint8_t *)name, strlen(name)); } -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 int shdw_pg_eq_fn(addr_t key1, addr_t key2) { + char * name1 = (char *)key1; + char * name2 = (char *)key2; + + return (strcmp(name1, name2) == 0); } -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); +int V3_init_shdw_paging() { + extern struct v3_shdw_pg_impl * __start__v3_shdw_pg_impls[]; + extern struct v3_shdw_pg_impl * __stop__v3_shdw_pg_impls[]; + struct v3_shdw_pg_impl ** tmp_impl = __start__v3_shdw_pg_impls; + int i = 0; - if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pde) == -1) { - return -1; - } + master_shdw_pg_table = v3_create_htable(0, shdw_pg_hash_fn, shdw_pg_eq_fn); - 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 - - return -1; + + while (tmp_impl != __stop__v3_shdw_pg_impls) { + V3_Print("Registering Shadow Paging Impl (%s)\n", (*tmp_impl)->name); + + if (v3_htable_search(master_shdw_pg_table, (addr_t)((*tmp_impl)->name))) { + PrintError("Multiple instances of shadow paging impl (%s)\n", (*tmp_impl)->name); + return -1; + } + + if (v3_htable_insert(master_shdw_pg_table, + (addr_t)((*tmp_impl)->name), + (addr_t)(*tmp_impl)) == 0) { + PrintError("Could not register shadow paging impl (%s)\n", (*tmp_impl)->name); + return -1; + } + + tmp_impl = &(__start__v3_shdw_pg_impls[++i]); + } + + return 0; +} + +int V3_deinit_shdw_paging() { + v3_free_htable(master_shdw_pg_table, 0, 0); + 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); +/*** + *** There be dragons + ***/ + + +#ifdef V3_CONFIG_SHADOW_PAGING_TELEMETRY +static void telemetry_cb(struct v3_vm_info * vm, void * private_data, char * hdr) { + int i = 0; + for (i = 0; i < vm->num_cores; i++) { + struct guest_info * core = &(vm->cores[i]); - return (addr_t)host_pde; + V3_Print("%s Guest Page faults: %d\n", hdr, core->shdw_pg_state.guest_faults); + } } +#endif + + + +int v3_init_shdw_pg_state(struct guest_info * core) { + struct v3_shdw_pg_state * state = &(core->shdw_pg_state); + struct v3_shdw_pg_impl * impl = core->vm_info->shdw_impl.current_impl; + + + state->guest_cr3 = 0; + state->guest_cr0 = 0; + state->guest_efer.value = 0x0LL; + if (impl->local_init(core) == -1) { + PrintError("Error in Shadow paging local initialization (%s)\n", impl->name); + return -1; + } -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; +#ifdef V3_CONFIG_SHADOW_PAGING_TELEMETRY + v3_add_telemetry_cb(core->vm_info, telemetry_cb, NULL); +#endif - // 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; - } - - V3_AllocPages(host_pde, 1); - memset(host_pde, 0, PAGE_SIZE); +} - 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) { +int v3_deinit_shdw_pg_state(struct guest_info * core) { + struct v3_shdw_pg_impl * impl = core->vm_info->shdw_impl.current_impl; + + if (impl->local_deinit(core) == -1) { + PrintError("Error deinitializing shadow paging state\n"); + return -1; + } + + + return 0; +} + + + +int v3_init_shdw_impl(struct v3_vm_info * vm) { + struct v3_shdw_impl_state * impl_state = &(vm->shdw_impl); + v3_cfg_tree_t * pg_cfg = v3_cfg_subtree(vm->cfg_data->cfg, "paging"); + char * pg_mode = v3_cfg_val(pg_cfg, "mode"); + char * pg_strat = v3_cfg_val(pg_cfg, "strategy"); + struct v3_shdw_pg_impl * impl = NULL; + + PrintDebug("Checking if shadow paging requested.\n"); + if ((pg_mode != NULL) && (strcasecmp(pg_mode, "nested") == 0)) { + PrintDebug("Nested paging specified - not initializing shadow paging.\n"); return 0; - } + } - if ((host_pte = setup_shadow_pte32(info, pt_host_addr)) == 0) { + if (pg_strat == NULL) { + pg_strat = (char *)default_strategy; + } + + V3_Print("Initialization of Shadow Paging implementation\n"); + + impl = (struct v3_shdw_pg_impl *)v3_htable_search(master_shdw_pg_table, (addr_t)pg_strat); + + if (impl == NULL) { + PrintError("Could not find shadow paging impl (%s)\n", pg_strat); + return -1; + } + + impl_state->current_impl = impl; + + if (impl->init(vm, pg_cfg) == -1) { + PrintError("Could not initialize Shadow paging implemenation (%s)\n", impl->name); + return -1; + } + + return 0; +} + +int v3_deinit_shdw_impl(struct v3_vm_info * vm) { + struct v3_shdw_pg_impl * impl = vm->shdw_impl.current_impl; + + if (impl == NULL) { + // Shadow paging not implemented return 0; - } + } + + if (impl->deinit(vm) == -1) { + PrintError("Error deinitializing shadow paging implementation\n"); + return -1; + } + + return 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 * core) { + struct v3_shdw_impl_state * state = &(core->vm_info->shdw_impl); + struct v3_shdw_pg_impl * impl = state->current_impl; + return impl->activate_shdw_pt(core); +} + + + +// This must flush any caches +// and reset the cr3 value to the correct value +int v3_invalidate_shadow_pts(struct guest_info * core) { + struct v3_shdw_impl_state * state = &(core->vm_info->shdw_impl); + struct v3_shdw_pg_impl * impl = state->current_impl; + return impl->invalidate_shdw_pt(core); +} - host_pde[i].present = 1; - host_pde[i].pt_base_addr = PD32_BASE_ADDR(host_pte); - // - // Set Page DIR flags - // +int v3_handle_shadow_pagefault(struct guest_info * core, addr_t fault_addr, pf_error_t error_code) { + + if (v3_get_vm_mem_mode(core) == PHYSICAL_MEM) { + // If paging is not turned on we need to handle the special cases + return v3_handle_passthrough_pagefault(core, fault_addr, error_code); + } else if (v3_get_vm_mem_mode(core) == VIRTUAL_MEM) { + struct v3_shdw_impl_state * state = &(core->vm_info->shdw_impl); + struct v3_shdw_pg_impl * impl = state->current_impl; + + return impl->handle_pagefault(core, fault_addr, error_code); + } else { + PrintError("Invalid Memory mode\n"); + return -1; + } +} + + +int v3_handle_shadow_invlpg(struct guest_info * core) { + uchar_t instr[15]; + struct x86_instr dec_instr; + int ret = 0; + addr_t vaddr = 0; + + if (v3_get_vm_mem_mode(core) != 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; } - } - PrintDebugPageTables(host_pde); + if (v3_get_vm_mem_mode(core) == PHYSICAL_MEM) { + ret = v3_read_gpa_memory(core, get_addr_linear(core, core->rip, &(core->segments.cs)), 15, instr); + } else { + ret = v3_read_gva_memory(core, get_addr_linear(core, core->rip, &(core->segments.cs)), 15, instr); + } + + if (ret == -1) { + PrintError("Could not read instruction into buffer\n"); + return -1; + } - return (addr_t)host_pde; + if (v3_decode(core, (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; + } + + vaddr = dec_instr.dst_operand.operand; + + core->rip += dec_instr.instr_length; + + { + struct v3_shdw_impl_state * state = &(core->vm_info->shdw_impl); + struct v3_shdw_pg_impl * impl = state->current_impl; + + return impl->handle_invlpg(core, vaddr); + } } -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); - 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; - page_type = get_shadow_addr_type(info, guest_pa); +int v3_inject_guest_pf(struct guest_info * core, addr_t fault_addr, pf_error_t error_code) { + core->ctrl_regs.cr2 = fault_addr; - if (page_type == HOST_REGION_PHYSICAL_MEMORY) { - host_pa = get_shadow_addr(info, guest_pa); - } else { - - // - // Setup various memory types - // - } +#ifdef V3_CONFIG_SHADOW_PAGING_TELEMETRY + core->shdw_pg_state.guest_faults++; +#endif - host_pte[i].page_base_addr = PT32_BASE_ADDR(host_pa); - host_pte[i].present = 1; + return v3_raise_exception_with_error(core, PF_EXCEPTION, *(uint_t *)&error_code); +} + + +int v3_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 (addr_t)host_pte; + return 0; }