X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=blobdiff_plain;f=palacios%2Fsrc%2Fpalacios%2Fvmm_shadow_paging.c;h=70a2c77ad905a4b9aba6f7e82c7fe1fb5b8a7b63;hb=eb87f60800c8634e37d1f8e71cd8f88605f2a46e;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..70a2c77 100644 --- a/palacios/src/palacios/vmm_shadow_paging.c +++ b/palacios/src/palacios/vmm_shadow_paging.c @@ -4,7 +4,7 @@ #include #include -extern struct vmm_os_hooks * os_hooks; + int init_shadow_page_state(struct shadow_page_state * state) { @@ -30,32 +30,208 @@ int handle_shadow_pagefault32(struct guest_info * info, addr_t fault_addr, pf_er 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); + pt_access_status_t guest_pde_access; + pt_access_status_t shadow_pde_access; + pde32_t * guest_pde_entry = NULL; + pde32_t * shadow_pde_entry = (pde32_t *)&(shadow_pde[PDE32_INDEX(fault_addr)]); if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pde) == -1) { + PrintDebug("Invalid Guest PDE Address: 0x%x\n", guest_cr3); + return -1; + } + + + guest_pde_entry = (pde32_t *)&(guest_pde[PDE32_INDEX(fault_addr)]); + + // Check the guest page permissions + guest_pde_access = can_access_pde32(guest_pde, fault_addr, error_code); + + if (guest_pde_access != PT_ACCESS_OK) { + + // + // inject page fault to the guest (Guest PDE fault) + // + + PrintDebug("Guest Page fault (currently not handled)\n"); return -1; } - if (error_code.present == 0) { - // Faulted because page was not present... - if (shadow_pde[PDE32_INDEX(fault_addr)].present) { - - + shadow_pde_access = can_access_pde32(shadow_pde, fault_addr, error_code); + + + if (shadow_pde_access == PT_ENTRY_NOT_PRESENT) { + pte32_t * shadow_pte = NULL; + + V3_AllocPages(shadow_pte, 1); + memset(shadow_pte, 0, PAGE_SIZE); + + shadow_pde_entry->pt_base_addr = PD32_BASE_ADDR(shadow_pte); + + + shadow_pde_entry->present = 1; + shadow_pde_entry->user_page = guest_pde_entry->user_page; + + // VMM Specific options + shadow_pde_entry->write_through = 0; + shadow_pde_entry->cache_disable = 0; + shadow_pde_entry->global_page = 0; + // + + guest_pde_entry->accessed = 1; + + if (guest_pde_entry->large_page == 0) { + shadow_pde_entry->writable = guest_pde_entry->writable; } else { + /* + * Check the Intel manual because we are ignoring Large Page issues here + */ + } + + } else if (shadow_pde_access == PT_WRITE_ERROR) { + + // + // Page Directory Entry marked read-only + // + + PrintDebug("Shadow Paging Write Error\n"); + return -1; + } else if (shadow_pde_access == PT_USER_ERROR) { + + // + // Page Directory Entry marked non-user + // + + PrintDebug("Shadow Paging User access error\n"); + return -1; + } else if (shadow_pde_access == PT_ACCESS_OK) { + pte32_t * shadow_pte = (pte32_t *)PDE32_T_ADDR((*shadow_pde_entry)); + pte32_t * guest_pte = NULL; + + // Page Table entry fault + + if (guest_pa_to_host_va(info, PDE32_T_ADDR((*guest_pde_entry)), (addr_t*)&guest_pte) == -1) { + PrintDebug("Invalid Guest PTE Address: 0x%x\n", PDE32_T_ADDR((*guest_pde_entry))); + return -1; + } + + + if (handle_shadow_pte32_fault(info, fault_addr, error_code, shadow_pte, guest_pte) == -1) { + PrintDebug("Error handling Page fault caused by PTE\n"); return -1; - } + } + + } else { + PrintDebug("Unknown Error\n"); + return -1; } - // Checks: - // Shadow PDE - // Guest PDE - // Shadow PTE - // Guest PTE - // Mem Map - - return -1; + PrintDebugPageTables(shadow_pde); + + return 0; } + +/* + * We assume the the guest pte pointer has already been translated to a host virtual address + */ +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) { + + pt_access_status_t guest_pte_access; + pt_access_status_t shadow_pte_access; + pte32_t * guest_pte_entry = (pte32_t *)&(guest_pte[PTE32_INDEX(fault_addr)]);; + pte32_t * shadow_pte_entry = (pte32_t *)&(shadow_pte[PTE32_INDEX(fault_addr)]); + + + // Check the guest page permissions + guest_pte_access = can_access_pte32(guest_pte, fault_addr, error_code); + + if (guest_pte_access != PT_ACCESS_OK) { + + // + // Inject page fault into the guest + // + + PrintDebug("Guest Page fault (currently not handled)\n"); + return -1; + } + + shadow_pte_access = can_access_pte32(shadow_pte, fault_addr, error_code); + + if (shadow_pte_access == PT_ENTRY_NOT_PRESENT) { + addr_t shadow_pa; + addr_t guest_pa = PTE32_T_ADDR((*guest_pte_entry)); + + // Page Table Entry Not Present + + if (get_shadow_addr_type(info, guest_pa) == HOST_REGION_INVALID) { + + // + // Inject a machine check in the guest + // + + PrintDebug("Invalid Guest Address in page table (0x%x)\n", guest_pa); + return -1; + } + + shadow_pa = get_shadow_addr(info, guest_pa); + + shadow_pte_entry->page_base_addr = PT32_BASE_ADDR(shadow_pa); + + shadow_pte_entry->present = guest_pte_entry->present; + shadow_pte_entry->user_page = guest_pte_entry->user_page; + + //set according to VMM policy + shadow_pte_entry->write_through = 0; + shadow_pte_entry->cache_disable = 0; + shadow_pte_entry->global_page = 0; + // + + guest_pte_entry->accessed = 1; + + if (guest_pte_entry->dirty == 1) { + shadow_pte_entry->writable = guest_pte_entry->writable; + } else if ((guest_pte_entry->dirty == 0) && (error_code.write == 1)) { + shadow_pte_entry->writable = guest_pte_entry->writable; + guest_pte_entry->dirty = 1; + } else if ((guest_pte_entry->dirty = 0) && (error_code.write == 0)) { + shadow_pte_entry->writable = 0; + } + + } else if (shadow_pte_access == PT_WRITE_ERROR) { + + // + // Page Table Entry marked read-only + // + + PrintDebug("Shadow Paging Write Error\n"); + return -1; + } else if (shadow_pte_access == PT_USER_ERROR) { + + // + // Page Table Entry marked non-user + // + + PrintDebug("Shadow Paging User access error\n"); + return -1; + } else if (shadow_pte_access == PT_ACCESS_OK) { + + PrintDebug("Page Fault occurred for No Reason\n"); + return -1; + } else { + PrintDebug("Unknown Error\n"); + return -1; + } + + return 0; +} + + + addr_t create_new_shadow_pt32(struct guest_info * info) { void * host_pde = 0;