X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=blobdiff_plain;f=palacios%2Fsrc%2Fpalacios%2Fvmm_shadow_paging.c;h=9650f135cb0f528b44fd2bf35b405f22d430f93e;hb=6fa605075d1944da0a88a389122ea24bbc583329;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..9650f13 100644 --- a/palacios/src/palacios/vmm_shadow_paging.c +++ b/palacios/src/palacios/vmm_shadow_paging.c @@ -1,147 +1,544 @@ +/* + * 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; + + +struct event_callback { + int (*callback)(struct guest_info *core, struct v3_shdw_pg_event *event, void *priv_data); + void *priv_data; + + struct list_head node; +}; + +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); } +static int have_callbacks(struct guest_info *core) +{ + // lock acquistion unnecessary + // caller will acquire the lock before *iterating* through the list + // so any race will be resolved then + return !list_empty(&(core->vm_info->shdw_impl.event_callback_list)); +} -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); +static void dispatch_event(struct guest_info *core, struct v3_shdw_pg_event *event) +{ + struct event_callback *cb,*temp; - if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pde) == -1) { - return -1; - } + v3_read_lock(&(core->vm_info->shdw_impl.event_callback_lock)); - 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; + list_for_each_entry_safe(cb, + temp, + &(core->vm_info->shdw_impl.event_callback_list), + node) { + cb->callback(core,event,cb->priv_data); + } + + v3_read_unlock(&(core->vm_info->shdw_impl.event_callback_lock)); +} + + +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; + + master_shdw_pg_table = v3_create_htable(0, shdw_pg_hash_fn, shdw_pg_eq_fn); + + + while (tmp_impl != __stop__v3_shdw_pg_impls) { + V3_Print(VM_NONE, VCORE_NONE, "Registering Shadow Paging Impl (%s)\n", (*tmp_impl)->name); + + if (v3_htable_search(master_shdw_pg_table, (addr_t)((*tmp_impl)->name))) { + PrintError(VM_NONE, VCORE_NONE, "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(VM_NONE, VCORE_NONE, "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 + ***/ - return (addr_t)host_pde; + +#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]); + + V3_Print(vm, core, "%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(core->vm_info, core, "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) { - return 0; - } +int v3_deinit_shdw_pg_state(struct guest_info * core) { + struct v3_shdw_pg_impl * impl = NULL; + + if (!core || !core->vm_info) { + return -1; + } + + impl = core->vm_info->shdw_impl.current_impl; + + if (impl && impl->local_deinit(core) == -1) { + PrintError(core->vm_info, core, "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(vm, VCORE_NONE, "Checking if shadow paging requested.\n"); + if (pg_mode == NULL) { + V3_Print(vm, VCORE_NONE, "No paging mode specified, assuming shadow with defaults\n"); + pg_mode = "shadow"; + } else { + if (strcasecmp(pg_mode, "nested") == 0) { + // this check is repeated here (compare to vmm_config's determine paging mode) since + // shadow paging initialization *precedes* per-core pre-config. + extern v3_cpu_arch_t v3_mach_type; + if ((v3_mach_type == V3_SVM_REV3_CPU) || + (v3_mach_type == V3_VMX_EPT_CPU) || + (v3_mach_type == V3_VMX_EPT_UG_CPU)) { + PrintDebug(vm, VCORE_NONE, "Nested paging specified on machine that supports it - not initializing shadow paging\n"); + return 0; + } else { + V3_Print(vm, VCORE_NONE, "Nested paging specified but machine does not support it - falling back to shadow paging with defaults\n"); + pg_mode = "shadow"; + } + } else if (strcasecmp(pg_mode, "shadow") != 0) { + V3_Print(vm, VCORE_NONE, "Unknown paging mode '%s' specified - falling back to shadow paging with defaults\n",pg_mode); + pg_mode = "shadow"; + } + } + + if (pg_strat == NULL) { + pg_strat = (char *)default_strategy; + } + + V3_Print(vm, VCORE_NONE,"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(vm, VCORE_NONE, "Could not find shadow paging impl (%s)\n", pg_strat); + return -1; + } + + INIT_LIST_HEAD(&(impl_state->event_callback_list)); + v3_rw_lock_init(&(impl_state->event_callback_lock)); + + impl_state->current_impl = impl; + + if (impl->init(vm, pg_cfg) == -1) { + PrintError(vm, VCORE_NONE, "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; + struct event_callback *cb,*temp; + addr_t flags; - if ((host_pte = setup_shadow_pte32(info, pt_host_addr)) == 0) { + if (impl == NULL) { + // Shadow paging not implemented return 0; - } + } + + if (impl->deinit(vm) == -1) { + PrintError(vm, VCORE_NONE,"Error deinitializing shadow paging implementation\n"); + return -1; + } + + flags=v3_write_lock_irqsave(&(vm->shdw_impl.event_callback_lock)); + + list_for_each_entry_safe(cb, + temp, + &(vm->shdw_impl.event_callback_list), + node) { + list_del(&(cb->node)); + V3_Free(cb); + } + + v3_write_unlock_irqrestore(&(vm->shdw_impl.event_callback_lock),flags); + + v3_rw_lock_deinit(&(vm->shdw_impl.event_callback_lock)); + + 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; + + if (!have_callbacks(core)) { + return impl->activate_shdw_pt(core); + } else { + int rc; + struct v3_shdw_pg_event event_pre={SHADOW_ACTIVATE,SHADOW_PREIMPL,0,{0,0,0,0,0,0}}; + struct v3_shdw_pg_event event_post={SHADOW_ACTIVATE,SHADOW_POSTIMPL,0,{0,0,0,0,0,0}}; + + dispatch_event(core,&event_pre); + + rc =impl->activate_shdw_pt(core); + + dispatch_event(core,&event_post); + + return rc; + } +} + + + +// 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; + + if (!have_callbacks(core)) { + return impl->invalidate_shdw_pt(core); + } else { + int rc; + struct v3_shdw_pg_event event_pre={SHADOW_INVALIDATE,SHADOW_PREIMPL,0,{0,0,0,0,0,0}}; + struct v3_shdw_pg_event event_post={SHADOW_INVALIDATE,SHADOW_POSTIMPL,0,{0,0,0,0,0,0}}; + + dispatch_event(core,&event_pre); + + rc = impl->invalidate_shdw_pt(core); + + dispatch_event(core,&event_post); + + return rc; + } +} + + +int v3_handle_shadow_pagefault(struct guest_info * core, addr_t fault_addr, pf_error_t error_code) +{ + int rc; + + + if (have_callbacks(core)) { + struct v3_shdw_pg_event event={SHADOW_PAGEFAULT,SHADOW_PREIMPL,fault_addr,error_code}; + dispatch_event(core,&event); + } + + if (v3_get_vm_mem_mode(core) == PHYSICAL_MEM) { + // If paging is not turned on we need to handle the special cases + rc = v3_handle_passthrough_pagefault(core, fault_addr, error_code,NULL,NULL); + } 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; + + rc = impl->handle_pagefault(core, fault_addr, error_code); + } else { + PrintError(core->vm_info, core, "Invalid Memory mode\n"); + rc = -1; + } + + if (have_callbacks(core)) { + struct v3_shdw_pg_event event={SHADOW_PAGEFAULT,SHADOW_POSTIMPL,fault_addr,error_code}; + dispatch_event(core,&event); + } + + return rc; +} - host_pde[i].present = 1; - host_pde[i].pt_base_addr = PD32_BASE_ADDR(host_pte); - // - // Set Page DIR flags - // +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(core->vm_info, core, "ERROR: INVLPG called in non paged mode\n"); + return -1; + } + + 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(core->vm_info, core, "Could not read instruction into buffer\n"); + return -1; } - } - PrintDebugPageTables(host_pde); + if (v3_decode(core, (addr_t)instr, &dec_instr) == -1) { + PrintError(core->vm_info, core, "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(core->vm_info, core, "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; + int rc; + + if (have_callbacks(core)) { + struct v3_shdw_pg_event event={SHADOW_INVLPG,SHADOW_PREIMPL,vaddr,{0,0,0,0,0,0}}; + dispatch_event(core,&event); + } + + rc=impl->handle_invlpg(core, vaddr); + + if (have_callbacks(core)) { + struct v3_shdw_pg_event event={SHADOW_INVLPG,SHADOW_POSTIMPL,vaddr,{0,0,0,0,0,0}}; + dispatch_event(core,&event); + } - return (addr_t)host_pde; + return rc; + } } -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; + +#ifdef V3_CONFIG_SHADOW_PAGING_TELEMETRY + core->shdw_pg_state.guest_faults++; +#endif + + return v3_raise_exception_with_error(core, PF_EXCEPTION, *(uint_t *)&error_code); +} + - if (page_type == HOST_REGION_PHYSICAL_MEMORY) { - host_pa = get_shadow_addr(info, guest_pa); - } else { +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; + } - // - // Setup various memory types - // - } + // Otherwise we'll handle the guest fault later...? + } + + return 0; +} + - host_pte[i].page_base_addr = PT32_BASE_ADDR(host_pa); - host_pte[i].present = 1; +int v3_register_shadow_paging_event_callback(struct v3_vm_info *vm, + int (*callback)(struct guest_info *core, + struct v3_shdw_pg_event *event, + void *priv_data), + void *priv_data) +{ + struct event_callback *ec = V3_Malloc(sizeof(struct event_callback)); + addr_t flags; + + if (!ec) { + PrintError(vm, VCORE_NONE, "Unable to allocate for a shadow paging event callback\n"); + return -1; } - } + + ec->callback = callback; + ec->priv_data = priv_data; + + flags=v3_write_lock_irqsave(&(vm->shdw_impl.event_callback_lock)); + list_add(&(ec->node),&(vm->shdw_impl.event_callback_list)); + v3_write_unlock_irqrestore(&(vm->shdw_impl.event_callback_lock),flags); - return (addr_t)host_pte; + return 0; + +} + +int v3_unregister_shadow_paging_event_callback(struct v3_vm_info *vm, + int (*callback)(struct guest_info *core, + struct v3_shdw_pg_event *event, + void *priv_data), + void *priv_data) +{ + struct event_callback *cb,*temp; + addr_t flags; + + flags=v3_write_lock_irqsave(&(vm->shdw_impl.event_callback_lock)); + + list_for_each_entry_safe(cb, + temp, + &(vm->shdw_impl.event_callback_list), + node) { + if ((callback == cb->callback) && (priv_data == cb->priv_data)) { + list_del(&(cb->node)); + v3_write_unlock_irqrestore(&(vm->shdw_impl.event_callback_lock),flags); + V3_Free(cb); + return 0; + } + } + + v3_write_unlock_irqrestore(&(vm->shdw_impl.event_callback_lock),flags); + + PrintError(vm, VCORE_NONE, "No callback found!\n"); + + return -1; }