#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) {
break;
case PROTECTED_PAE:
case LONG:
- // currently not handled
- return -1;
- break;
default:
+ 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) {
+ void * host_pde = 0;
+
+ V3_AllocPages(host_pde, 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;
+
+ 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);
+
+
+ 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;
+}
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_pde = (pde32_t *)&(shadow_pd[PDE32_INDEX(fault_addr)]);
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;
}
// Check the guest page permissions
guest_pde_access = can_access_pde32(guest_pd, fault_addr, error_code);
- if (guest_pde_access != PT_ACCESS_OK) {
+ // 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;
+ 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);
- PrintDebug("Guest CR3=%x\n", guest_cr3);
- PrintPD32(guest_pd);
- V3_ASSERT(0);
+ 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);
+ //shadow_pde_access = can_access_pde32(shadow_pd, fault_addr, error_code);
if (shadow_pde_access == PT_ENTRY_NOT_PRESENT) {
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;
+ guest_pde->accessed = 1;
if (guest_pde->large_page == 0) {
pte32_t * shadow_pt = NULL;
// addr_t guest_end_addr = guest_start_addr + PAGE_SIZE_4MB; // start address + 4MB
- /* JRL: THIS COULD BE A PROBLEM....
- * Currently we only support large pages if the region is mapped contiguosly in shadow memory
- * Lets hope this is the case...
- */
-
// 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);
+ 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;
// 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);
- // Check if the region is at least an additional 4MB
- if (region_end_addr <= host_start_addr + PAGE_SIZE_4MB) {
- PrintDebug("Large page over non contiguous host memory... Not handled\n");
- return -1;
- }
+ PrintDebug("Host Start Addr=%x; Region End Addr=%x\n", host_start_addr, region_end_addr);
+
+
- //4b.
- large_shadow_pde->page_base_addr = PD32_4MB_BASE_ADDR(host_start_addr);
//4f
if (large_guest_pde->dirty == 1) { // dirty
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) {
+ PrintError("Non Aligned Large Page Error\n");
+ V3_Free(shadow_pt);
+ 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) {
- PrintDebug("Special Page Fault handler returned error for address: %x\n", fault_addr);
+ PrintError("Special Page Fault handler returned error for address: %x\n", fault_addr);
return -1;
}
}
// Page Directory Entry marked non-user
//
- PrintDebug("Shadow Paging User access error\n");
- return -1;
+ 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;
if (handle_shadow_pte32_fault(info, fault_addr, error_code, shadow_pt, guest_pt) == -1) {
- PrintDebug("Error handling Page fault caused by PTE\n");
+ PrintError("Error handling Page fault caused by PTE\n");
return -1;
}
// this probably shouldn't ever happen
PrintDebug("Unknown Error occurred\n");
PrintDebug("Manual Says to inject page fault into guest\n");
- return -1;
+
+
+ return 0;
+
}
//PrintDebugPageTables(shadow_pd);
- PrintDebug("Returning end of PDE function\n");
+ PrintDebug("Returning end of PDE function (rip=%x)\n", info->rip);
return 0;
}
// Check the guest page permissions
guest_pte_access = can_access_pte32(guest_pt, fault_addr, error_code);
+ // 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
- if (guest_pte_access != PT_ACCESS_OK) {
+ /* 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\n");
- return 0;
+ 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;
}
- shadow_pte_access = can_access_pte32(shadow_pt, fault_addr, error_code);
+
if (shadow_pte_access == PT_ACCESS_OK) {
// Inconsistent state...
// Inject a machine check in the guest
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) {
} 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);
+ PrintError("Special Page fault handler returned error for address: %x\n", fault_addr);
return -1;
}
}
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");
+ 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;
}
-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;
-}
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;
}
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);
+
+ 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%x\n", guest_cr3);
+ return -1;
+ }
+
+
+
index += 2;
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;
//PrintDebug("PDE Index=%d\n", PDE32_INDEX(first_operand));
//PrintDebug("FirstOperand = %x\n", first_operand);
- if (shadow_pde->large_page == 1) {
+ PrintDebug("Invalidating page for %x\n", 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 *)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;
}
