Disallow startup with shadow paging + memory region outside 4GB boundary

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

diff --git a/palacios/src/palacios/vmm.c b/palacios/src/palacios/vmm.c
index 18871b0..0959feb 100644 (file)
--- a/palacios/src/palacios/vmm.c
+++ b/palacios/src/palacios/vmm.c
@@ -261,6 +261,22 @@ int v3_start_vm(struct v3_vm_info * vm, unsigned int cpu_mask) {
         return -1;
     }
 
+    
+    // Do not run if any core is using shadow paging and we are out of 4 GB bounds
+    for (i=0;i<vm->num_cores;i++) { 
+       if (vm->cores[i].shdw_pg_mode == SHADOW_PAGING) {
+           if ((vm->mem_map.base_region.host_addr + vm->mem_size ) >= 0x100000000ULL) {
+               PrintError("Base memory region exceeds 4 GB boundary with shadow paging enabled on core %d.\n",i);
+               PrintError("Any use of non-64 bit mode in the guest is likely to fail in this configuration.\n");
+               PrintError("If you would like to proceed anyway, remove this check and recompile Palacios.\n");
+               PrintError("Alternatively, change this VM to use nested paging.\n");
+               return -1;
+           }
+       }
+    }
+
+
+
     /// CHECK IF WE ARE MULTICORE ENABLED....
 
     V3_Print("V3 --  Starting VM (%u cores)\n", vm->num_cores);
@@ -457,6 +473,12 @@ int v3_move_vm_core(struct v3_vm_info * vm, int vcore_id, int target_cpu) {
 
 int v3_stop_vm(struct v3_vm_info * vm) {
 
+    if ((vm->run_state != VM_RUNNING) && 
+       (vm->run_state != VM_SIMULATING)) {
+       PrintError("Tried to stop VM in invalid runstate (%d)\n", vm->run_state);
+       return -1;
+    }
+
     vm->run_state = VM_STOPPED;
 
     // Sanity check to catch any weird execution states
@@ -649,6 +671,12 @@ int v3_free_vm(struct v3_vm_info * vm) {
     int i = 0;
     // deinitialize guest (free memory, etc...)
 
+    if ((vm->run_state != VM_STOPPED) &&
+       (vm->run_state != VM_ERROR)) {
+       PrintError("Tried to Free VM in invalid runstate (%d)\n", vm->run_state);
+       return -1;
+    }
+
     v3_free_vm_devices(vm);
 
     // free cores
@@ -718,7 +746,7 @@ void v3_yield_cond(struct guest_info * info, int usec) {
         info->yield_start_cycle +=  info->vm_info->yield_cycle_period;
     }
 }
-
+ 
 
 /* 
  * unconditional cpu yield