X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=blobdiff_plain;f=palacios%2Fsrc%2Fpalacios%2Fvmm_shadow_paging.c;h=6a0b3be9053632b01c9db701531a00d3428068ee;hb=53f181096ad02cde9f79e30e2238ddad43ede574;hp=c9546e4d30bfece0df576771d146f085bba7e568;hpb=a109eb919a162bd7de58d62020801bc2e633be50;p=palacios.git diff --git a/palacios/src/palacios/vmm_shadow_paging.c b/palacios/src/palacios/vmm_shadow_paging.c index c9546e4..6a0b3be 100644 --- a/palacios/src/palacios/vmm_shadow_paging.c +++ b/palacios/src/palacios/vmm_shadow_paging.c @@ -1,209 +1,334 @@ +/* + * 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 + +#ifndef DEBUG_SHADOW_PAGING +#undef PrintDebug +#define PrintDebug(fmt, args...) +#endif + + +/*** + *** There be dragons + ***/ + + +struct guest_table { + addr_t cr3; + struct list_head link; +}; + + +struct backptr { + addr_t ptr; + struct list_head link; +}; + + +struct shadow_page_data { + addr_t ptr; + addr_t guest_addr; + + struct list_head backptrs; + struct list_head guest_tables; +}; + + + + +//DEFINE_HASHTABLE_INSERT(add_cr3_to_cache, addr_t, struct hashtable *); +//DEFINE_HASHTABLE_SEARCH(find_cr3_in_cache, addr_t, struct hashtable *); +//DEFINE_HASHTABLE_REMOVE(del_cr3_from_cache, addr_t, struct hashtable *, 0); + + +DEFINE_HASHTABLE_INSERT(add_pte_map, addr_t, addr_t); +DEFINE_HASHTABLE_SEARCH(find_pte_map, addr_t, addr_t); +//DEFINE_HASHTABLE_REMOVE(del_pte_map, addr_t, addr_t, 0); + + + +static uint_t pte_hash_fn(addr_t key) { + return hash_long(key, 32); +} + +static int pte_equals(addr_t key1, addr_t key2) { + return (key1 == key2); +} -extern struct vmm_os_hooks * os_hooks; +static addr_t create_new_shadow_pt(); +static void 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); -int init_shadow_page_state(struct shadow_page_state * state) { - state->guest_mode = PDE32; - state->shadow_mode = PDE32; +#include "vmm_shadow_paging_32.h" +#include "vmm_shadow_paging_32pae.h" +#include "vmm_shadow_paging_64.h" + + + +int v3_init_shadow_page_state(struct guest_info * info) { + struct shadow_page_state * state = &(info->shdw_pg_state); - state->guest_cr3.r_reg = 0; - state->shadow_cr3.r_reg = 0; + state->guest_cr3 = 0; + state->guest_cr0 = 0; + + state->cached_ptes = NULL; return 0; } - -int wholesale_update_shadow_page_state(struct guest_info * guest_info) { - unsigned i, j; - pde32_t * guest_pde; - pde32_t * shadow_pde; - struct shadow_page_state * state = &(guest_info->shdw_pg_state); - // For now, we'll only work with PDE32 - if (state->guest_mode != PDE32) { + + + +// 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 (info->cpu_mode) { + + 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: %d\n", info->cpu_mode); return -1; } - shadow_pde = (pde32_t *)(CR3_TO_PDE32(state->shadow_cr3.e_reg.low)); + return 0; +} + - if (host_pa_to_host_va(CR3_TO_PDE32(state->guest_cr3.e_reg.low), (addr_t*)&guest_pde) != 0) { +int v3_activate_passthrough_pt(struct guest_info * info) { + // For now... But we need to change this.... + // As soon as shadow paging becomes active the passthrough tables are hosed + // So this will cause chaos if it is called at that time + + info->ctrl_regs.cr3 = *(addr_t*)&(info->direct_map_pt); + //PrintError("Activate Passthrough Page tables not implemented\n"); + return 0; +} + + + +int v3_handle_shadow_pagefault(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) { + + if (info->mem_mode == PHYSICAL_MEM) { + // If paging is not turned on we need to handle the special cases + +#ifdef DEBUG_SHADOW_PAGING + PrintHostPageTree(info->cpu_mode, fault_addr, info->ctrl_regs.cr3); + PrintGuestPageTree(info, fault_addr, info->shdw_pg_state.guest_cr3); +#endif + + return handle_special_page_fault(info, fault_addr, fault_addr, error_code); + } else if (info->mem_mode == VIRTUAL_MEM) { + + switch (info->cpu_mode) { + 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: + return handle_shadow_pagefault_64(info, fault_addr, error_code); + break; + default: + PrintError("Unhandled CPU Mode\n"); + return -1; + } + } else { + PrintError("Invalid Memory mode\n"); return -1; } +} + + + +static addr_t create_new_shadow_pt() { + void * host_pde = 0; + + host_pde = V3_VAddr(V3_AllocPages(1)); + memset(host_pde, 0, PAGE_SIZE); - // Delete the current page table - delete_page_tables_pde32(shadow_pde); + return (addr_t)host_pde; +} - shadow_pde = os_hooks->allocate_pages(1); - state->shadow_cr3.e_reg.low = (addr_t)shadow_pde; +static void inject_guest_pf(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) { + if (info->enable_profiler) { + info->profiler.guest_pf_cnt++; + } - state->shadow_mode = PDE32; + info->ctrl_regs.cr2 = fault_addr; + v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code); +} - for (i = 0; i < MAX_PDE32_ENTRIES; i++) { - shadow_pde[i] = guest_pde[i]; - // The shadow can be identical to the guest if it's not present - if (!shadow_pde[i].present) { - continue; +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_pde[i].large_pages) { - // large page - just map it through shadow map to generate its physical location - addr_t guest_addr = PAGE_ADDR(shadow_pde[i].pt_base_addr); - addr_t host_addr; - shadow_region_t * ent; + if ((shadow_access == PT_ACCESS_NOT_PRESENT) && + (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; +} - ent = get_shadow_region_by_addr(&(guest_info->mem_map), guest_addr); - - if (!ent) { - // FIXME Panic here - guest is trying to map to physical memory - // it does not own in any way! - return -1; - } - // FIXME Bounds check here to see if it's trying to trick us - - switch (ent->host_type) { - case HOST_REGION_PHYSICAL_MEMORY: - // points into currently allocated physical memory, so we just - // set up the shadow to point to the mapped location - if (guest_pa_to_host_pa(guest_info, guest_addr, &host_addr)) { - // Panic here - return -1; - } - - shadow_pde[i].pt_base_addr = PAGE_ALIGNED_ADDR(host_addr); - // FIXME set vmm_info bits here - break; - case HOST_REGION_UNALLOCATED: - // points to physical memory that is *allowed* but that we - // have not yet allocated. We mark as not present and set a - // bit to remind us to allocate it later - shadow_pde[i].present = 0; - // FIXME Set vminfo bits here so that we know that we will be - // allocating it later - break; - case HOST_REGION_NOTHING: - // points to physical memory that is NOT ALLOWED. - // We will mark it as not present and set a bit to remind - // us that it's bad later and insert a GPF then - shadow_pde[i].present = 0; - break; - case HOST_REGION_MEMORY_MAPPED_DEVICE: - case HOST_REGION_REMOTE: - case HOST_REGION_SWAPPED: - default: - // Panic. Currently unhandled - return -1; - break; - } - } else { - pte32_t * guest_pte; - pte32_t * shadow_pte; - addr_t guest_addr; - addr_t guest_pte_host_addr; - shadow_region_t * ent; - - // small page - set PDE and follow down to the child table - shadow_pde[i] = guest_pde[i]; - - guest_addr = PAGE_ADDR(guest_pde[i].pt_base_addr); - - // Allocate a new second level page table for the shadow - shadow_pte = os_hooks->allocate_pages(1); - - // make our first level page table in the shadow point to it - shadow_pde[i].pt_base_addr = PAGE_ALIGNED_ADDR(shadow_pte); - - ent = get_shadow_region_by_addr(&(guest_info->mem_map), guest_addr); - - /* JRL: This is bad.... */ - // For now the guest Page Table must always be mapped to host physical memory - /* If we swap out a page table or if it isn't present for some reason, this turns real ugly */ - if ((!ent) || (ent->host_type != HOST_REGION_PHYSICAL_MEMORY)) { - // FIXME Panic here - guest is trying to map to physical memory - // it does not own in any way! - return -1; - } - // Address of the relevant second level page table in the guest - if (guest_pa_to_host_pa(guest_info, guest_addr, &guest_pte_host_addr)) { - // Panic here - return -1; - } - // host_addr now contains the host physical address for the guest's 2nd level page table - // Now we transform it to relevant virtual address - guest_pte = os_hooks->paddr_to_vaddr((void *)guest_pte_host_addr); - // Now we walk through the second level guest page table - // and clone it into the shadow - for (j = 0; j < MAX_PTE32_ENTRIES; j++) { - shadow_pte[j] = guest_pte[j]; - addr_t guest_addr = PAGE_ADDR(shadow_pte[j].page_base_addr); - - shadow_region_t * ent; - ent = get_shadow_region_by_addr(&(guest_info->mem_map), guest_addr); + + +/* Currently Does not work with Segmentation!!! */ +int v3_handle_shadow_invlpg(struct guest_info * info) +{ + if (info->mem_mode != 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; + } + + + if (info->cpu_mode != PROTECTED) { + PrintError("Unsupported CPU mode (mode=%s)\n", v3_cpu_mode_to_str(info->cpu_mode)); + return -1; + } + + uchar_t instr[15]; + int index = 0; + + int ret = read_guest_va_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr); + if (ret != 15) { + PrintError("Could not read instruction 0x%p (ret=%d)\n", (void *)(addr_t)(info->rip), ret); + return -1; + } + + + /* Can INVLPG work with Segments?? */ + while (is_prefix_byte(instr[index])) { + index++; + } + + + if( (instr[index + 0] != (uchar_t) 0x0f) || + (instr[index + 1] != (uchar_t) 0x01) ) { + PrintError("invalid Instruction Opcode\n"); + PrintTraceMemDump(instr, 15); + return -1; + } + + addr_t first_operand; + addr_t second_operand; + addr_t guest_cr3 = CR3_TO_PDE32_PA(info->shdw_pg_state.guest_cr3); + + pde32_t * guest_pd = NULL; + + if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pd) == -1) { + PrintError("Invalid Guest PDE Address: 0x%p\n", (void *)guest_cr3); + return -1; + } + + index += 2; + + v3_operand_type_t addr_type = decode_operands32(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG32); + + if (addr_type != MEM_OPERAND) { + PrintError("Invalid Operand type\n"); + return -1; + } + + pde32_t * shadow_pd = (pde32_t *)CR3_TO_PDE32_VA(info->ctrl_regs.cr3); + pde32_t * shadow_pde = (pde32_t *)&shadow_pd[PDE32_INDEX(first_operand)]; + pde32_t * guest_pde; + + //PrintDebug("PDE Index=%d\n", PDE32_INDEX(first_operand)); + //PrintDebug("FirstOperand = %x\n", first_operand); + + PrintDebug("Invalidating page for %p\n", (void *)first_operand); + + guest_pde = (pde32_t *)&(guest_pd[PDE32_INDEX(first_operand)]); + + if (guest_pde->large_page == 1) { + shadow_pde->present = 0; + PrintDebug("Invalidating Large Page\n"); + } else + if (shadow_pde->present == 1) { + pte32_t * shadow_pt = (pte32_t *)(addr_t)BASE_TO_PAGE_ADDR(shadow_pde->pt_base_addr); + pte32_t * shadow_pte = (pte32_t *) V3_VAddr( (void*) &shadow_pt[PTE32_INDEX(first_operand)] ); - if (!ent) { - // FIXME Panic here - guest is trying to map to physical memory - // it does not own in any way! - return -1; - } - - switch (ent->host_type) { - case HOST_REGION_PHYSICAL_MEMORY: - { - addr_t host_addr; - - // points into currently allocated physical memory, so we just - // set up the shadow to point to the mapped location - if (guest_pa_to_host_pa(guest_info, guest_addr, &host_addr)) { - // Panic here - return -1; - } - - shadow_pte[j].page_base_addr = PAGE_ALIGNED_ADDR(host_addr); - // FIXME set vmm_info bits here - break; - } - case HOST_REGION_UNALLOCATED: - // points to physical memory that is *allowed* but that we - // have not yet allocated. We mark as not present and set a - // bit to remind us to allocate it later - shadow_pte[j].present = 0; - // FIXME Set vminfo bits here so that we know that we will be - // allocating it later - break; - case HOST_REGION_NOTHING: - // points to physical memory that is NOT ALLOWED. - // We will mark it as not present and set a bit to remind - // us that it's bad later and insert a GPF then - shadow_pte[j].present = 0; - break; - case HOST_REGION_MEMORY_MAPPED_DEVICE: - case HOST_REGION_REMOTE: - case HOST_REGION_SWAPPED: - default: - // Panic. Currently unhandled - return -1; - break; - } - } +#ifdef DEBUG_SHADOW_PAGING + PrintDebug("Setting not present\n"); + PrintPTEntry(PAGE_PT32, first_operand, shadow_pte); +#endif + + shadow_pte->present = 0; } - } + + info->rip += index; + return 0; } - +