Updated to include improved 8254

[palacios.git] / palacios / src / palacios / vmm_ctrl_regs.c

diff --git a/palacios/src/palacios/vmm_ctrl_regs.c b/palacios/src/palacios/vmm_ctrl_regs.c
index 4dba737..4b0ff65 100644 (file)
--- a/palacios/src/palacios/vmm_ctrl_regs.c
+++ b/palacios/src/palacios/vmm_ctrl_regs.c
@@ -146,6 +146,12 @@ int handle_cr0_write(struct guest_info * info) {
          info->cpu_mode = PROTECTED;
        }
 
+       if (new_cr0->pe == 0) { 
+         PrintDebug("Entering Real Mode\n");
+         info->cpu_mode = REAL;
+       }
+         
+
        if (new_cr0->pg == 1) {
          PrintDebug("Paging is already turned on in switch to protected mode in CR0 write\n");
 
@@ -483,6 +489,9 @@ int handle_cr0_read(struct guest_info * info) {
 
        if (info->shdw_pg_mode == SHADOW_PAGING) {
          *virt_cr0 = *(struct cr0_32 *)&(info->shdw_pg_state.guest_cr0);
+         if (info->cpu_mode==PROTECTED) {
+           virt_cr0->pg=0; // clear the pg bit because guest doesn't think it's on
+         }
        } else {
          *virt_cr0 = *real_cr0;
        }
@@ -526,10 +535,14 @@ int handle_cr3_write(struct guest_info * info) {
     int ret;
     char instr[15];
 
+    PrintDebug("Protected %s mode write to CR3 at %s 0x%x\n",
+              info->cpu_mode==PROTECTED ? "" : "Paged", 
+              info->cpu_mode==PROTECTED ? "guest physical" : "guest virtual",
+              get_addr_linear(info,info->rip,&(info->segments.cs)));
 
     // We need to read the instruction, which is at CS:IP, but that 
     // linear address is guest physical without PG and guest virtual with PG
-    if (info->cpu_mode == PHYSICAL_MEM) { 
+    if (info->mem_mode == PHYSICAL_MEM) { 
       // The real rip address is actually a combination of the rip + CS base 
       PrintDebug("Writing Guest CR3 Write (Physical Address)\n");
       ret = read_guest_pa_memory(info, get_addr_linear(info, info->rip, &(info->segments.cs)), 15, instr);
@@ -539,7 +552,6 @@ int handle_cr3_write(struct guest_info * info) {
       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 (ret=%d)\n", ret);
       return -1;
@@ -612,10 +624,11 @@ int handle_cr3_write(struct guest_info * info) {
 
     } else {
       PrintDebug("Unknown Instruction\n");
+      SerialMemDump(instr,15);
       return -1;
     }
   } else {
-    PrintDebug("Invalid operating Mode\n");
+    PrintDebug("Invalid operating Mode (0x%x)\n", info->cpu_mode);
     return -1;
   }
 
@@ -679,10 +692,11 @@ int handle_cr3_read(struct guest_info * info) {
       info->rip += index;
     } else {
       PrintDebug("Unknown Instruction\n");
+      SerialMemDump(instr,15);
       return -1;
     }
   } else {
-    PrintDebug("Invalid operating Mode\n");
+    PrintDebug("Invalid operating Mode (0x%x)\n", info->cpu_mode);
     return -1;
   }