#include <palacios/vm_guest_mem.h>
#include <palacios/vmm_decoder.h>
+#ifndef DEBUG_SHADOW_PAGING
+#undef PrintDebug
+#define PrintDebug(fmt, args...)
+#endif
-int init_shadow_page_state(struct shadow_page_state * state) {
+/***
+ *** There be dragons
+ ***/
+
+
+
+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);
+
+static int handle_shadow_pagefault32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code);
+
+int init_shadow_page_state(struct guest_info * info) {
+ struct shadow_page_state * state = &(info->shdw_pg_state);
state->guest_mode = PDE32;
state->shadow_mode = PDE32;
return 0;
}
+
+
+
+
+
+int v3_replace_shdw_page32(struct guest_info * info, addr_t location, pte32_t * new_page, pte32_t * old_page) {
+ 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(location)]);
+
+ if (shadow_pde->large_page == 0) {
+ pte32_t * shadow_pt = (pte32_t *)PDE32_T_ADDR((*shadow_pde));
+ pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(location)]);
+
+ //if (shadow_pte->present == 1) {
+ *(uint_t *)old_page = *(uint_t *)shadow_pte;
+ //}
+
+ *(uint_t *)shadow_pte = *(uint_t *)new_page;
+
+ } else {
+ // currently unhandled
+ return -1;
+ }
+
+ return 0;
+}
+
+
+
+
+
+
int 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
- return handle_special_page_fault(info, fault_addr, error_code);
+ 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_PAE:
case LONG:
default:
- PrintDebug("Unhandled CPU Mode\n");
+ PrintError("Unhandled CPU Mode\n");
return -1;
}
} else {
- PrintDebug("Invalid Memory mode\n");
+ PrintError("Invalid Memory mode\n");
return -1;
}
}
-addr_t create_new_shadow_pt32(struct guest_info * info) {
+addr_t create_new_shadow_pt32() {
void * host_pde = 0;
- V3_AllocPages(host_pde, 1);
+ 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 void inject_guest_pf(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
+ info->ctrl_regs.cr2 = fault_addr;
+ v3_raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code);
+}
- 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);
+
+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
- pte_cursor = &(pt[i]);
+ if ((shadow_access != PT_ENTRY_NOT_PRESENT) &&
+ (guest_access != PT_ENTRY_NOT_PRESENT)) {
+ // aka (guest permission error)
+ return 1;
+ }
+
+ if ((shadow_access == PT_ENTRY_NOT_PRESENT) &&
+ (guest_access == PT_ENTRY_NOT_PRESENT)) {
+ // Page tables completely blank, handle guest first
+ return 1;
+ }
+
+ // Otherwise we'll handle the guest fault later...?
+ }
+
+ return 0;
+}
+
+
+
+
+/* The guest status checks have already been done,
+ * only special case shadow checks remain
+ */
+static int handle_large_pagefault32(struct guest_info * info,
+ addr_t fault_addr, pf_error_t error_code,
+ pte32_t * shadow_pt, pde32_4MB_t * large_guest_pde)
+{
+ pt_access_status_t shadow_pte_access = can_access_pte32(shadow_pt, fault_addr, error_code);
+ pte32_t * shadow_pte = (pte32_t *)&(shadow_pt[PTE32_INDEX(fault_addr)]);
+
+ if (shadow_pte_access == PT_ACCESS_OK) {
+ // Inconsistent state...
+ // Guest Re-Entry will flush tables and everything should now workd
+ PrintDebug("Inconsistent state... Guest re-entry should flush tlb\n");
+ return 0;
+ }
+
+
+ if (shadow_pte_access == PT_ENTRY_NOT_PRESENT) {
+ // Get the guest physical address of the fault
+ addr_t guest_fault_pa = PDE32_4MB_T_ADDR(*large_guest_pde) + PD32_4MB_PAGE_OFFSET(fault_addr);
+ host_region_type_t host_page_type = get_shadow_addr_type(info, guest_fault_pa);
+
if (host_page_type == HOST_REGION_INVALID) {
- // Currently we don't support this, but in theory we could
- PrintDebug("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);
+ // Inject a machine check in the guest
+ PrintDebug("Invalid Guest Address in page table (0x%x)\n", guest_fault_pa);
+ v3_raise_exception(info, MC_EXCEPTION);
+ return 0;
+ }
+ if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) {
+ addr_t shadow_pa = get_shadow_addr(info, guest_fault_pa);
- 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;
+ shadow_pte->page_base_addr = PT32_BASE_ADDR(shadow_pa);
+
+ shadow_pte->present = 1;
+
+ /* We are assuming that the PDE entry has precedence
+ * so the Shadow PDE will mirror the guest PDE settings,
+ * and we don't have to worry about them here
+ * Allow everything
+ */
+ shadow_pte->user_page = 1;
+ shadow_pte->writable = 1;
+ //set according to VMM policy
+ shadow_pte->write_through = 0;
+ shadow_pte->cache_disable = 0;
+ shadow_pte->global_page = 0;
+ //
+
} else {
- PrintDebug("Unsupported Host Memory Type\n");
- return -1;
+ // Handle hooked pages as well as other special pages
+ if (handle_special_page_fault(info, fault_addr, guest_fault_pa, error_code) == -1) {
+ PrintError("Special Page Fault handler returned error for address: %x\n", fault_addr);
+ return -1;
+ }
}
+ } else {
+ PrintError("Error in large page fault handler...\n");
+ PrintError("This case should have been handled at the top level handler\n");
+ return -1;
}
+
+ PrintDebug("Returning from large page fault handler\n");
return 0;
}
-int handle_shadow_pagefault32(struct guest_info * info, addr_t fault_addr, pf_error_t error_code) {
+
+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);
pde32_t * guest_pde = NULL;
pde32_t * shadow_pde = (pde32_t *)&(shadow_pd[PDE32_INDEX(fault_addr)]);
+ PrintDebug("Shadow page fault handler\n");
+
if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pd) == -1) {
- PrintDebug("Invalid Guest PDE Address: 0x%x\n", guest_cr3);
+ PrintError("Invalid Guest PDE Address: 0x%x\n", guest_cr3);
return -1;
- }
-
+ }
guest_pde = (pde32_t *)&(guest_pd[PDE32_INDEX(fault_addr)]);
+
// Check the guest page permissions
guest_pde_access = can_access_pde32(guest_pd, fault_addr, error_code);
// Check the shadow page permissions
shadow_pde_access = can_access_pde32(shadow_pd, fault_addr, error_code);
- /* 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;
- 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);
+ /* Was the page fault caused by the Guest's page tables? */
+ if (is_guest_pf(guest_pde_access, shadow_pde_access) == 1) {
+ PrintDebug("Injecting PDE pf to guest: (guest access error=%d) (pf error code=%d)\n",
+ guest_pde_access, error_code);
+ inject_guest_pf(info, fault_addr, error_code);
return 0;
-
-
- /*
- PrintDebug("Guest CR3=%x\n", guest_cr3);
- PrintDebug("Guest PD\n");
- PrintPD32(guest_pd);
- PrintDebug("Shadow PD\n");
- PrintPD32(shadow_pd);
- */
-
- return -1;
}
+
+ if (shadow_pde_access == PT_ENTRY_NOT_PRESENT)
+ {
+ pte32_t * shadow_pt = (pte32_t *)create_new_shadow_pt32();
+
+ shadow_pde->present = 1;
+ shadow_pde->user_page = guest_pde->user_page;
+ // shadow_pde->large_page = guest_pde->large_page;
+ shadow_pde->large_page = 0;
+
- //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;
+ // VMM Specific options
+ shadow_pde->write_through = 0;
+ shadow_pde->cache_disable = 0;
+ shadow_pde->global_page = 0;
+ //
- V3_AllocPages(shadow_pt, 1);
- memset(shadow_pt, 0, PAGE_SIZE);
+ guest_pde->accessed = 1;
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) {
-
- raise_exception(info, MC_EXCEPTION);
- PrintDebug("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;
- V3_AllocPages(shadow_pt, 1);
- memset(shadow_pt, 0, PAGE_SIZE);
-
- if (handle_pd32_nonaligned_4MB_page(info, shadow_pt, guest_start_addr, large_shadow_pde) == -1) {
- PrintDebug("Non Aligned Large Page Error\n");
- V3_Free(shadow_pt);
- return -1;
- }
-
-
- /*
- PrintDebug("non-aligned Shadow PT\n");
- PrintPT32(PT32_PAGE_ADDR(fault_addr), shadow_pt);
- */
- shadow_pde->pt_base_addr = PD32_BASE_ADDR(shadow_pt);
+ if (guest_pde->large_page == 0) {
+ shadow_pde->writable = guest_pde->writable;
+ } else {
+ ((pde32_4MB_t *)guest_pde)->dirty = 0;
+ shadow_pde->writable = 0;
+ }
+ }
+ else if (shadow_pde_access == PT_ACCESS_OK)
+ {
+ //
+ // PTE fault
+ //
+ pte32_t * shadow_pt = (pte32_t *)PDE32_T_ADDR((*shadow_pde));
+
+ if (guest_pde->large_page == 0) {
+ pte32_t * guest_pt = NULL;
+ if (guest_pa_to_host_va(info, PDE32_T_ADDR((*guest_pde)), (addr_t*)&guest_pt) == -1) {
+ // Machine check the guest
+ PrintDebug("Invalid Guest PTE Address: 0x%x\n", PDE32_T_ADDR((*guest_pde)));
+ v3_raise_exception(info, MC_EXCEPTION);
+ return 0;
}
-
- } else {
- // Handle hooked pages as well as other special pages
- if (handle_special_page_fault(info, fault_addr, error_code) == -1) {
- PrintDebug("Special Page Fault handler returned error for address: %x\n", fault_addr);
+ 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;
+ }
+ } else if (guest_pde->large_page == 1) {
+ if (handle_large_pagefault32(info, fault_addr, error_code, shadow_pt, (pde32_4MB_t *)guest_pde) == -1) {
+ PrintError("Error handling large pagefault\n");
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;
- 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
-
- raise_exception(info, MC_EXCEPTION);
+ 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
+ // Its a large page and we need to update the dirty bit in the guest
+ //
+ PrintDebug("Large page write error... Setting dirty bit and returning\n");
+ ((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)\n",
+ shadow_pde_access, guest_pde_access);
+ inject_guest_pf(info, fault_addr, error_code);
return 0;
}
-
-
- if (handle_shadow_pte32_fault(info, fault_addr, error_code, shadow_pt, guest_pt) == -1) {
- PrintDebug("Error handling Page fault caused by PTE\n");
- return -1;
+ else
+ {
+ // inject page fault in guest
+ inject_guest_pf(info, fault_addr, error_code);
+ PrintDebug("Unknown Error occurred (shadow_pde_access=%d)\n", shadow_pde_access);
+ PrintDebug("Manual Says to inject page fault into guest\n");
+#ifdef DEBUG_SHADOW_PAGING
+ PrintDebug("Guest PDE: (access=%d)\n\t", guest_pde_access);
+ PrintPDE32(fault_addr, guest_pde);
+ PrintDebug("Shadow PDE: (access=%d)\n\t", shadow_pde_access);
+ PrintPDE32(fault_addr, shadow_pde);
+#endif
+
+ return 0;
}
- } else {
- // Unknown error raise page fault in guest
- info->ctrl_regs.cr2 = fault_addr;
- 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;
}
/*
* 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_pt,
- pte32_t * guest_pt) {
+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;
// 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);
- /* 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;
- 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, error_code);
+#endif
+
+ /* Was the page fault caused by the Guest's page tables? */
+ if (is_guest_pf(guest_pte_access, shadow_pte_access) == 1) {
+ PrintDebug("Access error injecting pf to guest (guest access error=%d) (pf error code=%d)\n",
+ guest_pte_access, *(uint_t*)&error_code);
+ inject_guest_pf(info, fault_addr, error_code);
return 0;
}
-
-
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));
+ }
+
+
+ if (shadow_pte_access == PT_ENTRY_NOT_PRESENT) {
+
+ addr_t guest_pa = PTE32_T_ADDR((*guest_pte)) + PT32_PAGE_OFFSET(fault_addr);
// Page Table Entry Not Present
if (host_page_type == HOST_REGION_INVALID) {
// Inject a machine check in the guest
-
- raise_exception(info, MC_EXCEPTION);
-
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");
+ v3_raise_exception(info, MC_EXCEPTION);
return 0;
+ }
- } else if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) {
-
- shadow_pa = get_shadow_addr(info, guest_pa);
+ // else...
+
+ if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) {
+ addr_t shadow_pa = get_shadow_addr(info, guest_pa);
shadow_pte->page_base_addr = PT32_BASE_ADDR(shadow_pa);
}
} else {
// Page fault handled by hook functions
- if (handle_special_page_fault(info, fault_addr, error_code) == -1) {
- PrintDebug("Special Page fault handler returned error for address: %x\n", fault_addr);
+ if (handle_special_page_fault(info, fault_addr, guest_pa, error_code) == -1) {
+ PrintError("Special Page fault handler returned error for address: %x\n", fault_addr);
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");
-
+ guest_pte->dirty = 1;
+ shadow_pte->writable = guest_pte->writable;
return 0;
+
} else {
// Inject page fault into the guest
-
- info->ctrl_regs.cr2 = fault_addr;
- raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code);
-
- PrintDebug("PTE Page fault fell through... Not sure if this should ever happen\n");
- PrintDebug("Manual Says to inject page fault into guest\n");
+ inject_guest_pf(info, fault_addr, 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;
}
if (info->mem_mode != VIRTUAL_MEM) {
// Paging must be turned on...
// should handle with some sort of fault I think
- PrintDebug("ERROR: INVLPG called in non paged mode\n");
+ PrintError("ERROR: INVLPG called in non paged mode\n");
return -1;
}
ret = read_guest_va_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
if (ret != 15) {
- PrintDebug("Could not read instruction 0x%x (ret=%d)\n", info->rip, ret);
+ PrintError("Could not read instruction 0x%x (ret=%d)\n", info->rip, ret);
return -1;
}
pde32_t * guest_pd = NULL;
if (guest_pa_to_host_va(info, guest_cr3, (addr_t*)&guest_pd) == -1) {
- PrintDebug("Invalid Guest PDE Address: 0x%x\n", guest_cr3);
+ PrintError("Invalid Guest PDE Address: 0x%x\n", guest_cr3);
return -1;
}
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)];
+
+#ifdef DEBUG_SHADOW_PAGING
PrintDebug("Setting not present\n");
PrintPTE32(first_operand, shadow_pte);
+#endif
+
shadow_pte->present = 0;
}
}
info->rip += index;
} else {
- PrintDebug("Invalid Operand type\n");
+ PrintError("Invalid Operand type\n");
return -1;
}
} else {
- PrintDebug("invalid Instruction Opcode\n");
+ PrintError("invalid Instruction Opcode\n");
PrintTraceMemDump(instr, 15);
return -1;
}
}
-
-/* Deprecated */
/*
-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;
- }
+static int create_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;
- if ((host_pte = setup_shadow_pte32(info, pt_host_addr)) == 0) {
- return 0;
- }
+ 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]);
- host_pde[i].present = 1;
- host_pde[i].pt_base_addr = PD32_BASE_ADDR(host_pte);
+ 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);
- //
- // Set Page DIR flags
- //
- }
- }
- PrintDebugPageTables(host_pde);
+ 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;
- return (addr_t)host_pde;
+ } else {
+ PrintError("Unsupported Host Memory Type\n");
+ return -1;
+ }
+ }
+ return 0;
}
+static int handle_large_pagefault32(struct guest_info * info,
+ pde32_t * guest_pde, pde32_t * shadow_pde,
+ addr_t fault_addr, pf_error_t error_code ) {
+ 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) {
+ PrintError("Invalid guest address in large page (0x%x)\n", guest_start_addr);
+ v3_raise_exception(info, MC_EXCEPTION);
+ return -1;
+ }
+
+ // else...
-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;
+ if (host_page_type == HOST_REGION_PHYSICAL_MEMORY) {
- page_type = get_shadow_addr_type(info, guest_pa);
+ 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 = create_new_shadow_pt32();
- if (page_type == HOST_REGION_PHYSICAL_MEMORY) {
- host_pa = get_shadow_addr(info, guest_pa);
- } else {
-
- //
- // Setup various memory types
- //
+ if (create_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);
+ return -1;
}
-
- host_pte[i].page_base_addr = PT32_BASE_ADDR(host_pa);
- host_pte[i].present = 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, guest_start_addr, error_code) == -1) {
+ PrintError("Special Page Fault handler returned error for address: %x\n", fault_addr);
+ return -1;
}
}
- return (addr_t)host_pte;
+ return 0;
}
-
*/
