#include <palacios/vmm_shadow_paging.h>
+
#include <palacios/vmm.h>
#include <palacios/vm_guest_mem.h>
-extern struct vmm_os_hooks * os_hooks;
+
int init_shadow_page_state(struct shadow_page_state * state) {
state->guest_mode = PDE32;
state->shadow_mode = PDE32;
- state->guest_cr3.r_reg = 0;
- state->shadow_cr3.r_reg = 0;
+ state->guest_cr3 = 0;
+ state->shadow_cr3 = 0;
return 0;
}
-
-int wholesale_update_shadow_page_state(struct guest_info * guest_info) {
- unsigned i, j;
- pde32_t * guest_pde;
- pde32_t * shadow_pde;
+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;
+ }
+}
- struct shadow_page_state * state = &(guest_info->shdw_pg_state);
+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);
+ 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)]);
- // For now, we'll only work with PDE32
- if (state->guest_mode != PDE32) {
+ 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;
}
- shadow_pde = (pde32_t *)(CR3_TO_PDE32(state->shadow_cr3.e_reg.low));
- if (host_pa_to_host_va(CR3_TO_PDE32(state->guest_cr3.e_reg.low), (addr_t*)&guest_pde) != 0) {
+ 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;
}
- // Delete the current page table
- delete_page_tables_pde32(shadow_pde);
+ shadow_pde_access = can_access_pde32(shadow_pde, fault_addr, error_code);
- shadow_pde = os_hooks->allocate_pages(1);
- state->shadow_cr3.e_reg.low = (addr_t)shadow_pde;
+ if (shadow_pde_access == PT_ENTRY_NOT_PRESENT) {
+ pte32_t * shadow_pte = NULL;
- state->shadow_mode = PDE32;
+ V3_AllocPages(shadow_pte, 1);
+ memset(shadow_pte, 0, PAGE_SIZE);
- for (i = 0; i < MAX_PDE32_ENTRIES; i++) {
- shadow_pde[i] = guest_pde[i];
+ shadow_pde_entry->pt_base_addr = PD32_BASE_ADDR(shadow_pte);
+
- // The shadow can be identical to the guest if it's not present
- if (!shadow_pde[i].present) {
- continue;
- }
+ 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;
+ //
- 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;
-
- 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;
- }
+ guest_pde_entry->accessed = 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;
- }
+ if (guest_pde_entry->large_page == 0) {
+ shadow_pde_entry->writable = guest_pde_entry->writable;
} 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;
+ /*
+ * 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;
+ }
+
+ 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;
+
+ V3_AllocPages(host_pde, 1);
+ memset(host_pde, 0, PAGE_SIZE);
+
+ return (addr_t)host_pde;
+}
+
+
+
+
+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;
+
+ // 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;
}
- // 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;
+ if ((host_pte = setup_shadow_pte32(info, pt_host_addr)) == 0) {
+ return 0;
}
+ host_pde[i].present = 1;
+ host_pde[i].pt_base_addr = PD32_BASE_ADDR(host_pte);
- // 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);
+ //
+ // Set Page DIR flags
+ //
+ }
+ }
- // 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];
+ PrintDebugPageTables(host_pde);
- addr_t guest_addr = PAGE_ADDR(shadow_pte[j].page_base_addr);
+ return (addr_t)host_pde;
+}
+
+
+
+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);
+
+ if (page_type == HOST_REGION_PHYSICAL_MEMORY) {
+ host_pa = get_shadow_addr(info, guest_pa);
+ } else {
- shadow_region_t * ent;
-
- 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;
- }
-
- 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;
- }
+ //
+ // Setup various memory types
+ //
}
+
+ host_pte[i].page_base_addr = PT32_BASE_ADDR(host_pa);
+ host_pte[i].present = 1;
}
}
- return 0;
+
+ return (addr_t)host_pte;
}
-
+
