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=3c794314a82e34f7b32df9e8fc4b73490b3849f0;hb=0e097100a26bc43eb8964734fa43130fc4c71429;hpb=6c28cc8753bb0e1b17b5c6c2ee296eb60e09079c diff --git a/palacios/src/palacios/vmm_shadow_paging.c b/palacios/src/palacios/vmm_shadow_paging.c index 3c79431..0afc383 100644 --- a/palacios/src/palacios/vmm_shadow_paging.c +++ b/palacios/src/palacios/vmm_shadow_paging.c @@ -1,586 +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 -#ifndef DEBUG_SHADOW_PAGING -#undef PrintDebug -#define PrintDebug(fmt, args...) -#endif - +#include +#include +#ifdef CONFIG_SHADOW_PAGING_TELEMETRY +#include +#endif +#ifdef CONFIG_SYMBIOTIC_SWAP +#include +#endif -static int handle_shadow_pte32_fault(struct guest_info* info, - addr_t fault_addr, - pf_error_t error_code, - pte32_t * shadow_pte, - pte32_t * guest_pte); +#ifndef CONFIG_DEBUG_SHADOW_PAGING +#undef PrintDebug +#define PrintDebug(fmt, args...) +#endif -static int handle_shadow_pagefault32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code); -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; +/*** + *** There be dragons + ***/ - return 0; -} -int handle_shadow_pagefault(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) { +struct shadow_page_data { + v3_reg_t cr3; + addr_t page_pa; - if (info->mem_mode == PHYSICAL_MEM) { - // If paging is not turned on we need to handle the special cases - return handle_special_page_fault(info, fault_addr, error_code); - } else if (info->mem_mode == VIRTUAL_MEM) { - - switch (info->cpu_mode) { - case PROTECTED: - return handle_shadow_pagefault32(info, fault_addr, error_code); - break; - case PROTECTED_PAE: - case LONG: - default: - PrintError("Unhandled CPU Mode\n"); - return -1; - } - } else { - PrintError("Invalid Memory mode\n"); - return -1; - } -} - -addr_t create_new_shadow_pt32(struct guest_info * info) { - void * host_pde = 0; + struct list_head page_list_node; +}; - host_pde = V3_AllocPages(1); - memset(host_pde, 0, PAGE_SIZE); - - return (addr_t)host_pde; -} -static int handle_pd32_nonaligned_4MB_page(struct guest_info * info, pte32_t * pt, addr_t guest_addr, pde32_4MB_t * large_shadow_pde) { - uint_t i = 0; - pte32_t * pte_cursor; - addr_t guest_pa = 0; +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); - for (i = 0; i < 1024; i++) { - guest_pa = guest_addr + (PAGE_SIZE * i); - host_region_type_t host_page_type = get_shadow_addr_type(info, guest_pa); - - pte_cursor = &(pt[i]); - if (host_page_type == HOST_REGION_INVALID) { - // Currently we don't support this, but in theory we could - PrintError("Invalid Host Memory Type\n"); - return -1; - } else if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) { - addr_t shadow_pa = get_shadow_addr(info, guest_pa); +#include "vmm_shadow_paging_32.h" +#include "vmm_shadow_paging_32pae.h" +#include "vmm_shadow_paging_64.h" - pte_cursor->page_base_addr = PT32_BASE_ADDR(shadow_pa); - pte_cursor->present = 1; - pte_cursor->writable = large_shadow_pde->writable; - pte_cursor->user_page = large_shadow_pde->user_page; - pte_cursor->write_through = 0; - pte_cursor->cache_disable = 0; - pte_cursor->global_page = 0; - } else { - PrintError("Unsupported Host Memory Type\n"); - return -1; - } - } - return 0; +#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 -static int handle_shadow_pagefault32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) { - pde32_t * guest_pd = NULL; - pde32_t * shadow_pd = (pde32_t *)CR3_TO_PDE32(info->shdw_pg_state.shadow_cr3); - addr_t guest_cr3 = CR3_TO_PDE32(info->shdw_pg_state.guest_cr3); - pt_access_status_t guest_pde_access; - pt_access_status_t shadow_pde_access; - pde32_t * guest_pde = NULL; - pde32_t * shadow_pde = (pde32_t *)&(shadow_pd[PDE32_INDEX(fault_addr)]); - - if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pd) == -1) { - PrintError("Invalid Guest PDE Address: 0x%x\n", guest_cr3); - return -1; - } - guest_pde = (pde32_t *)&(guest_pd[PDE32_INDEX(fault_addr)]); +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; - // Check the guest page permissions - guest_pde_access = can_access_pde32(guest_pd, fault_addr, error_code); + INIT_LIST_HEAD(&(state->page_list)); - // Check the shadow page permissions - shadow_pde_access = can_access_pde32(shadow_pd, fault_addr, error_code); +#ifdef CONFIG_SHADOW_PAGING_TELEMETRY + if (info->enable_telemetry) { + v3_add_telemetry_cb(info, telemetry_cb, NULL); + } +#endif - /* This should be redone, - but 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_pde_access != PT_ACCESS_OK) && - ( - ( (shadow_pde_access != PT_ENTRY_NOT_PRESENT) && - (guest_pde_access != PT_ENTRY_NOT_PRESENT)) // aka (guest permission error) - || - ( (shadow_pde_access == PT_ENTRY_NOT_PRESENT) && - (guest_pde_access == PT_ENTRY_NOT_PRESENT)))) { - // inject page fault to the guest (Guest PDE fault) - - info->ctrl_regs.cr2 = fault_addr; - v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code); - - - PrintDebug("Injecting PDE pf to guest: (guest access error=%d) (pf error code=%d)\n", guest_pde_access, error_code); return 0; - - -#ifdef DEBUG_SHADOW_PAGING - PrintDebug("Guest CR3=%x\n", guest_cr3); - PrintDebug("Guest PD\n"); - PrintPD32(guest_pd); - PrintDebug("Shadow PD\n"); - PrintPD32(shadow_pd); -#endif - - return -1; - } - - - //shadow_pde_access = can_access_pde32(shadow_pd, fault_addr, error_code); - - - if (shadow_pde_access == PT_ENTRY_NOT_PRESENT) { - - shadow_pde->present = 1; - shadow_pde->user_page = guest_pde->user_page; - shadow_pde->large_page = guest_pde->large_page; - - - // VMM Specific options - shadow_pde->write_through = 0; - shadow_pde->cache_disable = 0; - shadow_pde->global_page = 0; - // - - guest_pde->accessed = 1; - - if (guest_pde->large_page == 0) { - pte32_t * shadow_pt = NULL; - - shadow_pt = V3_AllocPages(1); - memset(shadow_pt, 0, PAGE_SIZE); - - shadow_pde->pt_base_addr = PD32_BASE_ADDR(shadow_pt); - - shadow_pde->writable = guest_pde->writable; - } else { - struct shadow_region * mem_reg; - pde32_4MB_t * large_guest_pde = (pde32_4MB_t *)guest_pde; - pde32_4MB_t * large_shadow_pde = (pde32_4MB_t *)shadow_pde; - host_region_type_t host_page_type; - addr_t guest_start_addr = PDE32_4MB_T_ADDR(*large_guest_pde); - // addr_t guest_end_addr = guest_start_addr + PAGE_SIZE_4MB; // start address + 4MB - - - // Check that the Guest PDE entry points to valid memory - // else Machine Check the guest - PrintDebug("Large Page: Page Base Addr=%x\n", guest_start_addr); - - host_page_type = get_shadow_addr_type(info, guest_start_addr); - - if (host_page_type == HOST_REGION_INVALID) { - - v3_raise_exception(info, MC_EXCEPTION); - PrintError("Invalid guest address in large page (0x%x)\n", guest_start_addr); - return -1; - } else if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) { - addr_t host_start_addr = 0; - addr_t region_end_addr = 0; - - // Check for a large enough region in host memory - mem_reg = get_shadow_region_by_addr(&(info->mem_map), guest_start_addr); - PrintDebug("Host region: host_addr=%x (guest_start=%x, end=%x)\n", - mem_reg->host_addr, mem_reg->guest_start, mem_reg->guest_end); - host_start_addr = mem_reg->host_addr + (guest_start_addr - mem_reg->guest_start); - region_end_addr = mem_reg->host_addr + (mem_reg->guest_end - mem_reg->guest_start); - - PrintDebug("Host Start Addr=%x; Region End Addr=%x\n", host_start_addr, region_end_addr); - - - - - //4f - if (large_guest_pde->dirty == 1) { // dirty - large_shadow_pde->writable = guest_pde->writable; - } else if (error_code.write == 1) { // not dirty, access is write - large_shadow_pde->writable = guest_pde->writable; - large_guest_pde->dirty = 1; - } else { // not dirty, access is read - large_shadow_pde->writable = 0; - } - - - // Check if the region is at least an additional 4MB +} - //4b. - if ((PD32_4MB_PAGE_OFFSET(host_start_addr) == 0) && - (region_end_addr >= host_start_addr + PAGE_SIZE_4MB)) { // if 4MB boundary - large_shadow_pde->page_base_addr = PD32_4MB_BASE_ADDR(host_start_addr); - } else { // else generate 4k pages - pte32_t * shadow_pt = NULL; - PrintDebug("Handling non aligned large page\n"); - shadow_pde->large_page = 0; - - shadow_pt = V3_AllocPages(1); - memset(shadow_pt, 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)) { - if (handle_pd32_nonaligned_4MB_page(info, shadow_pt, guest_start_addr, large_shadow_pde) == -1) { - PrintError("Non Aligned Large Page Error\n"); - V3_Free(shadow_pt); + 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; - } - - -#ifdef DEBUG_SHADOW_PAGING - PrintDebug("non-aligned Shadow PT\n"); - PrintPT32(PT32_PAGE_ADDR(fault_addr), shadow_pt); -#endif - shadow_pde->pt_base_addr = PD32_BASE_ADDR(shadow_pt); - } - - - } else { - // Handle hooked pages as well as other special pages - if (handle_special_page_fault(info, fault_addr, error_code) == -1) { - PrintError("Special Page Fault handler returned error for address: %x\n", fault_addr); - return -1; - } - } } - } else if ((shadow_pde_access == PT_WRITE_ERROR) && - (guest_pde->large_page = 1) && - (((pde32_4MB_t *)guest_pde)->dirty == 0)) { - - // - // Page Directory Entry marked read-only - // - - ((pde32_4MB_t *)guest_pde)->dirty = 1; - shadow_pde->writable = guest_pde->writable; - return 0; - - } else if (shadow_pde_access == PT_USER_ERROR) { - - // - // Page Directory Entry marked non-user - // - - PrintDebug("Shadow Paging User access error (shadow_pde_access=0x%x, guest_pde_access=0x%x - injecting into guest\n", shadow_pde_access, guest_pde_access); - info->ctrl_regs.cr2 = fault_addr; - v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code); return 0; +} - } else if (shadow_pde_access == PT_ACCESS_OK) { - pte32_t * shadow_pt = (pte32_t *)PDE32_T_ADDR((*shadow_pde)); - pte32_t * guest_pt = NULL; - // Page Table Entry fault - - if (guest_pa_to_host_va(info, PDE32_T_ADDR((*guest_pde)), (addr_t*)&guest_pt) == -1) { - PrintDebug("Invalid Guest PTE Address: 0x%x\n", PDE32_T_ADDR((*guest_pde))); - // Machine check the guest - v3_raise_exception(info, MC_EXCEPTION); - - 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); +} - if (handle_shadow_pte32_fault(info, fault_addr, error_code, shadow_pt, guest_pt) == -1) { - PrintError("Error handling Page fault caused by PTE\n"); - return -1; +int v3_handle_shadow_pagefault(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) { + + 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; } - - } else { - // Unknown error raise page fault in guest - info->ctrl_regs.cr2 = fault_addr; - v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code); - - // For debugging we will return an error here for the time being, - // this probably shouldn't ever happen - PrintDebug("Unknown Error occurred\n"); - PrintDebug("Manual Says to inject page fault into guest\n"); - - - return 0; - - } - - //PrintDebugPageTables(shadow_pd); - PrintDebug("Returning end of PDE function (rip=%x)\n", info->rip); - 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; -/* - * We assume the the guest pte pointer has already been translated to a host virtual address - */ -static int handle_shadow_pte32_fault(struct guest_info * info, - addr_t fault_addr, - pf_error_t error_code, - pte32_t * shadow_pt, - pte32_t * guest_pt) { - - pt_access_status_t guest_pte_access; - pt_access_status_t shadow_pte_access; - pte32_t * guest_pte = (pte32_t *)&(guest_pt[PTE32_INDEX(fault_addr)]);; - pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(fault_addr)]); + 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; + } + 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); + } - // Check the guest page permissions - guest_pte_access = can_access_pte32(guest_pt, fault_addr, error_code); + if (ret == -1) { + PrintError("Could not read instruction into buffer\n"); + return -1; + } - // Check the shadow page permissions - shadow_pte_access = can_access_pte32(shadow_pt, fault_addr, error_code); - -#ifdef DEBUG_SHADOW_PAGING - PrintDebug("Guest PTE: (access=%d)\n\t", guest_pte_access); - PrintPTE32(fault_addr, guest_pte); - PrintDebug("Shadow PTE: (access=%d)\n\t", shadow_pte_access); - PrintPTE32(fault_addr, shadow_pte); -#endif - - /* This should be redone, - but 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_pte_access != PT_ACCESS_OK) && - ( - ((shadow_pte_access != PT_ENTRY_NOT_PRESENT) && - (guest_pte_access != PT_ENTRY_NOT_PRESENT)) // aka (guest permission error) - || - ((shadow_pte_access == PT_ENTRY_NOT_PRESENT) && - (guest_pte_access == PT_ENTRY_NOT_PRESENT)))) { - // Inject page fault into the guest - - info->ctrl_regs.cr2 = fault_addr; - v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code); - - PrintDebug("Access error injecting pf to guest (guest access error=%d) (pf error code=%d)\n", guest_pte_access, *(uint_t*)&error_code); - return 0; - } - + if (v3_decode(info, (addr_t)instr, &dec_instr) == -1) { + PrintError("Decoding Error\n"); + return -1; + } - - - if (shadow_pte_access == PT_ACCESS_OK) { - // Inconsistent state... - // Guest Re-Entry will flush page tables and everything should now work - PrintDebug("Inconsistent state... Guest re-entry should flush tlb\n"); - return 0; - } else if (shadow_pte_access == PT_ENTRY_NOT_PRESENT) { - addr_t shadow_pa; - addr_t guest_pa = PTE32_T_ADDR((*guest_pte)); - - // Page Table Entry Not Present - - host_region_type_t host_page_type = get_shadow_addr_type(info, guest_pa); - - if (host_page_type == HOST_REGION_INVALID) { - // Inject a machine check in the guest - - v3_raise_exception(info, MC_EXCEPTION); -#ifdef DEBUG_SHADOW_PAGING - PrintDebug("Invalid Guest Address in page table (0x%x)\n", guest_pa); - PrintDebug("fault_addr=0x%x next are guest and shadow ptes \n",fault_addr); - PrintPTE32(fault_addr,guest_pte); - PrintPTE32(fault_addr,shadow_pte); - PrintDebug("Done.\n"); -#endif - return 0; - - } else if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) { - - shadow_pa = get_shadow_addr(info, guest_pa); - - shadow_pte->page_base_addr = PT32_BASE_ADDR(shadow_pa); - - shadow_pte->present = guest_pte->present; - shadow_pte->user_page = guest_pte->user_page; - - //set according to VMM policy - shadow_pte->write_through = 0; - shadow_pte->cache_disable = 0; - shadow_pte->global_page = 0; - // - - guest_pte->accessed = 1; - - if (guest_pte->dirty == 1) { - shadow_pte->writable = guest_pte->writable; - } else if ((guest_pte->dirty == 0) && (error_code.write == 1)) { - shadow_pte->writable = guest_pte->writable; - guest_pte->dirty = 1; - } else if ((guest_pte->dirty = 0) && (error_code.write == 0)) { - shadow_pte->writable = 0; - } - } else { - // Page fault handled by hook functions - if (handle_special_page_fault(info, fault_addr, error_code) == -1) { - PrintError("Special Page fault handler returned error for address: %x\n", fault_addr); + 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; - } } - } else if ((shadow_pte_access == PT_WRITE_ERROR) && - (guest_pte->dirty == 0)) { - guest_pte->dirty = 1; - shadow_pte->writable = guest_pte->writable; - - PrintDebug("Shadow PTE Write Error\n"); - - return 0; - } else { - // Inject page fault into the guest - - info->ctrl_regs.cr2 = fault_addr; - v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code); - - PrintError("PTE Page fault fell through... Not sure if this should ever happen\n"); - PrintError("Manual Says to inject page fault into guest\n"); - return -1; - } - - PrintDebug("Returning end of function\n"); - return 0; + 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; + } } +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; + 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)); -/* Currently Does not work with Segmentation!!! */ -int 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; - } + list_move(&(page_tail->page_list_node), &(state->page_list)); + memset(V3_VAddr((void *)(page_tail->page_pa)), 0, PAGE_SIZE_4KB); - if (info->cpu_mode == PROTECTED) { - char instr[15]; - int ret; - int index = 0; - 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%x (ret=%d)\n", info->rip, ret); - return -1; - } - - - /* Can INVLPG work with Segments?? */ - while (is_prefix_byte(instr[index])) { - index++; + return page_tail; + } } - - - if ((instr[index] == (uchar_t)0x0f) && - (instr[index + 1] == (uchar_t)0x01)) { - addr_t first_operand; - addr_t second_operand; - operand_type_t addr_type; - addr_t guest_cr3 = CR3_TO_PDE32(info->shdw_pg_state.guest_cr3); + // else - pde32_t * guest_pd = NULL; + page_tail = (struct shadow_page_data *)V3_Malloc(sizeof(struct shadow_page_data)); + page_tail->page_pa = (addr_t)V3_AllocPages(1); - if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pd) == -1) { - PrintError("Invalid Guest PDE Address: 0x%x\n", guest_cr3); - return -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); - index += 2; + return page_tail; +} - addr_type = decode_operands32(&(info->vm_regs), instr + index, &index, &first_operand, &second_operand, REG32); - if (addr_type == MEM_OPERAND) { - pde32_t * shadow_pd = (pde32_t *)CR3_TO_PDE32(info->shdw_pg_state.shadow_cr3); - pde32_t * shadow_pde = (pde32_t *)&shadow_pd[PDE32_INDEX(first_operand)]; - pde32_t * guest_pde; +static int inject_guest_pf(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) { + info->ctrl_regs.cr2 = fault_addr; - //PrintDebug("PDE Index=%d\n", PDE32_INDEX(first_operand)); - //PrintDebug("FirstOperand = %x\n", first_operand); +#ifdef CONFIG_SHADOW_PAGING_TELEMETRY + info->shdw_pg_state.guest_faults++; +#endif - PrintDebug("Invalidating page for %x\n", first_operand); + return v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code); +} - 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 *)PDE32_T_ADDR((*shadow_pde)); - pte32_t * shadow_pte = (pte32_t *)&shadow_pt[PTE32_INDEX(first_operand)]; +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 -#ifdef DEBUG_SHADOW_PAGING - PrintDebug("Setting not present\n"); - PrintPTE32(first_operand, shadow_pte); -#endif + whew... + */ + if (guest_access != PT_ACCESS_OK) { + // Guest Access Error - shadow_pte->present = 0; - } + if ((shadow_access != PT_ACCESS_NOT_PRESENT) && + (guest_access != PT_ACCESS_NOT_PRESENT)) { + // aka (guest permission error) + return 1; } - info->rip += index; + /* + if ((shadow_access == PT_ACCESS_NOT_PRESENT) && + (guest_access == PT_ACCESS_NOT_PRESENT)) { + // Page tables completely blank, handle guest first + return 1; + } + */ - } else { - PrintError("Invalid Operand type\n"); - return -1; - } - } else { - PrintError("invalid Instruction Opcode\n"); - PrintTraceMemDump(instr, 15); - 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; + return 0; }