X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=blobdiff_plain;f=palacios%2Fsrc%2Fpalacios%2Fvmm_shadow_paging.c;h=72be8e71151df8c608d83beac3ce487f8b6a1883;hb=1da53ce8f6ab61d298d38cf3f1c4fcd9b1050ce8;hp=3350f43ebd9b52c03bd28b6a19bb441d4e4f739a;hpb=9ed850393ba752a7c0bb83673b5ff98f9573f2da;p=palacios.git

diff --git a/palacios/src/palacios/vmm_shadow_paging.c b/palacios/src/palacios/vmm_shadow_paging.c
index 3350f43..72be8e7 100644
--- a/palacios/src/palacios/vmm_shadow_paging.c
+++ b/palacios/src/palacios/vmm_shadow_paging.c
@@ -47,13 +47,12 @@ int handle_shadow_pagefault32(struct guest_info * info, addr_t fault_addr, pf_er
   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;
+    info->ctrl_regs.cr2 = fault_addr;
+    raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code);
+
+    return 0;
   }
 
   shadow_pde_access = can_access_pde32(shadow_pde, fault_addr, error_code);
@@ -107,11 +106,15 @@ int handle_shadow_pagefault32(struct guest_info * info, addr_t fault_addr, pf_er
     pte32_t * shadow_pte = (pte32_t *)PDE32_T_ADDR((*shadow_pde_entry));
     pte32_t * guest_pte = NULL;
 
-    // Page Table entry fault
+    // 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;
+      // Machine check the guest
+
+      raise_exception(info, MC_EXCEPTION);
+      
+      return 0;
     }
 
 
@@ -120,7 +123,17 @@ int handle_shadow_pagefault32(struct guest_info * info, addr_t fault_addr, pf_er
       return -1;
     }
 
- }
+ } 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 -1;
+  }
 
   PrintDebugPageTables(shadow_pde);
 
@@ -132,7 +145,7 @@ int handle_shadow_pagefault32(struct guest_info * info, addr_t fault_addr, pf_er
 /* 
  * 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, 
+int handle_shadow_pte32_fault(struct guest_info * info, 
 			      addr_t fault_addr, 
 			      pf_error_t error_code,
 			      pte32_t * shadow_pte, 
@@ -140,55 +153,86 @@ int handle_shadow_pte32_fault(struct guest_info* info,
 
   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)]);
+  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	
+    
+    info->ctrl_regs.cr2 = fault_addr;
+    raise_exception_with_error(info, PF_EXCEPTION, *(uint_t *)&error_code);
+    
+    return 0;
+  }
+  
+  
+  shadow_pte_access = can_access_pte32(shadow_pte, fault_addr, error_code);
 
-    //
-    // Inject page fault into the guest		
-    //
+  if (shadow_pte_access == PT_ACCESS_OK) {
+    // Inconsistent state...
+    // Guest Re-Entry will flush page tables and everything should now work
+    return 0;
+  } else if (shadow_pte_access == PT_ENTRY_NOT_PRESENT) {
+    addr_t shadow_pa;
+    addr_t guest_pa = PTE32_T_ADDR((*guest_pte_entry));
 
-    PrintDebug("Guest Page fault (currently not handled)\n");
-    return -1;
-  }
+    // Page Table Entry Not Present
 
+    if (get_shadow_addr_type(info, guest_pa) == HOST_REGION_INVALID) {
+      // Inject a machine check in the guest
 
-  shadow_pte_access = can_access_pte32(shadow_pte, fault_addr, error_code);
+      raise_exception(info, MC_EXCEPTION);
 
-  if (shadow_pte_access == PT_ENTRY_NOT_PRESENT) {
+      PrintDebug("Invalid Guest Address in page table (0x%x)\n", guest_pa);
+      return 0;
+    }
 
-    //
-    // Page Table Entry Not Present
-    //
+    shadow_pa = get_shadow_addr(info, guest_pa);
 
-  } else if (shadow_pte_access == PT_WRITE_ERROR) {
+    shadow_pte_entry->page_base_addr = PT32_BASE_ADDR(shadow_pa);
 
-    //
-    // Page Table Entry marked read-only
+    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;
     //
 
-    PrintDebug("Shadow Paging Write Error\n");
-    return -1;
-  } else if (shadow_pte_access == PT_USER_ERROR) {
+    guest_pte_entry->accessed = 1;
 
-    //
-    // Page Table Entry marked non-user
-    //
-    
-    PrintDebug("Shadow Paging User access error\n");
-    return -1;
-  } else if (shadow_pte_access == PT_ACCESS_OK) {
+    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) &&
+	     (guest_pte_entry->dirty == 0)) {
+    guest_pte_entry->dirty = 1;
+    shadow_pte_entry->writable = guest_pte_entry->writable;
 
-    PrintDebug("Page Fault occurred for No Reason\n");
+    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");
     return -1;
   }
 
-
   return 0;
 }
 
@@ -206,6 +250,8 @@ addr_t create_new_shadow_pt32(struct guest_info * info) {
 
 
 
+/* 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;
@@ -282,4 +328,4 @@ addr_t setup_shadow_pte32(struct guest_info * info, addr_t pt_host_addr) {
   return (addr_t)host_pte;
 }
 
-
+*/