Assorted bug fixes and defensive programming

- Sanity check top-level v3_ calls from host
- Eliminate vm free bug when config of shadow-paging vm terminates before passthrough paging is initialized
- Linux module - avoid v3_stop/free on cleanup for orphaned VMs (guest_map out of sync)

diff --git a/linux_module/main.c b/linux_module/main.c
index 2da1b22..38a2fd4 100644 (file)
--- a/linux_module/main.c
+++ b/linux_module/main.c
@@ -684,8 +684,13 @@ static void __exit v3_exit(void) {
 
     /* Stop and free any running VMs */ 
     for (i = 0; i < MAX_VMS; i++) {
-       if (guest_map[i] != NULL) {
-                guest = (struct v3_guest *)guest_map[i];
+               if (guest_map[i] != NULL) {
+                   guest = (struct v3_guest *)(guest_map[i]);
+
+               if (!guest->v3_ctx) { 
+                   ERROR("Orphan VM detected and skipped: index=%d name=%s\n", i, guest->name);
+                   continue;
+               }
 
                 if (v3_stop_vm(guest->v3_ctx) < 0) 
                         ERROR("Couldn't stop VM %d\n", i);

diff --git a/palacios/include/palacios/vmm_paging.h b/palacios/include/palacios/vmm_paging.h
index 9b95d1b..ca426af 100644 (file)
--- a/palacios/include/palacios/vmm_paging.h
+++ b/palacios/include/palacios/vmm_paging.h
@@ -573,6 +573,7 @@ pdpe32pae_t * create_passthrough_pts_32PAE(struct guest_info * guest_info);
 pml4e64_t * create_passthrough_pts_64(struct guest_info * info);
 
 
+// note that these take host virtual addresses  
 void delete_page_tables_32(pde32_t * pde);
 void delete_page_tables_32pae(pdpe32pae_t * pdpe);
 void delete_page_tables_64(pml4e64_t *  pml4);

diff --git a/palacios/src/palacios/vmm.c b/palacios/src/palacios/vmm.c
index e16e2fa..490f106 100644 (file)
--- a/palacios/src/palacios/vmm.c
+++ b/palacios/src/palacios/vmm.c
@@ -345,6 +345,11 @@ int v3_start_vm(struct v3_vm_info * vm, unsigned int cpu_mask) {
     uint32_t avail_cores = 0;
     int vcore_id = 0;
 
+    if (!vm) { 
+        PrintError(VM_NONE, VCORE_NONE, "Asked to start nonexistent VM\n");
+       return -1;
+    }
+
     if (vm->run_state != VM_STOPPED) {
         PrintError(vm, VCORE_NONE, "VM has already been launched (state=%d)\n", (int)vm->run_state);
         return -1;
@@ -449,6 +454,11 @@ int v3_reset_vm_core(struct guest_info * core, addr_t rip) {
 int v3_move_vm_core(struct v3_vm_info * vm, int vcore_id, int target_cpu) {
     struct guest_info * core = NULL;
 
+    if (!vm) { 
+        PrintError(VM_NONE, VCORE_NONE, "Asked to move core of nonexistent VM\n");
+       return -1;
+    }
+
     if ((vcore_id < 0) || (vcore_id >= vm->num_cores)) {
         PrintError(vm, VCORE_NONE, "Attempted to migrate invalid virtual core (%d)\n", vcore_id);
        return -1;
@@ -526,6 +536,11 @@ int v3_move_vm_mem(struct v3_vm_info * vm, void *gpa, int target_cpu) {
     void *old_hpa;
     int i;
 
+    if (!vm) { 
+        PrintError(VM_NONE, VCORE_NONE, "Asked to move memory of nonexistent VM\n");
+       return -1;
+    }
+
     old_node = v3_numa_gpa_to_node(vm,(addr_t)gpa);
 
     if (old_node<0) { 
@@ -634,6 +649,11 @@ int v3_stop_vm(struct v3_vm_info * vm) {
 
     struct guest_info * running_core;
 
+    if (!vm) { 
+        PrintError(VM_NONE, VCORE_NONE, "Asked to stop nonexistent VM\n");
+       return -1;
+    }
+
     if ((vm->run_state != VM_RUNNING) && 
        (vm->run_state != VM_SIMULATING)) {
         PrintError(vm, VCORE_NONE,"Tried to stop VM in invalid runstate (%d)\n", vm->run_state);
@@ -675,6 +695,11 @@ int v3_stop_vm(struct v3_vm_info * vm) {
 
 int v3_pause_vm(struct v3_vm_info * vm) {
 
+    if (!vm) { 
+        PrintError(VM_NONE, VCORE_NONE, "Asked to pause nonexistent VM\n");
+       return -1;
+    }
+
     if (vm->run_state != VM_RUNNING) {
        PrintError(vm, VCORE_NONE,"Tried to pause a VM that was not running\n");
        return -1;
@@ -690,6 +715,11 @@ int v3_pause_vm(struct v3_vm_info * vm) {
 
 int v3_continue_vm(struct v3_vm_info * vm) {
 
+    if (!vm) { 
+        PrintError(VM_NONE, VCORE_NONE, "Asked to continue nonexistent VM\n");
+       return -1;
+    }
+
     if (vm->run_state != VM_PAUSED) {
        PrintError(vm, VCORE_NONE,"Tried to continue a VM that was not paused\n");
        return -1;
@@ -729,6 +759,11 @@ int v3_simulate_vm(struct v3_vm_info * vm, unsigned int msecs) {
     uint64_t cycles = 0;
     uint64_t cpu_khz = V3_CPU_KHZ();
 
+    if (!vm) { 
+        PrintError(VM_NONE, VCORE_NONE, "Asked to simulate nonexistent VM\n");
+       return -1;
+    }
+
     if (vm->run_state != VM_PAUSED) {
        PrintError(vm, VCORE_NONE,"VM must be paused before simulation begins\n");
        return -1;
@@ -811,10 +846,18 @@ int v3_get_state_vm(struct v3_vm_info        *vm,
                    struct v3_vm_mem_state   *mem)
 {
     uint32_t i;
-    uint32_t numcores = core->num_vcores > vm->num_cores ? vm->num_cores : core->num_vcores;
-    uint32_t numregions = mem->num_regions > vm->mem_map.num_base_regions ? vm->mem_map.num_base_regions : mem->num_regions;
+    uint32_t numcores;
+    uint32_t numregions; 
     extern uint64_t v3_mem_block_size;
 
+    if (!vm || !base || !core || !mem)  { 
+        PrintError(VM_NONE, VCORE_NONE, "Invalid rquest to v3_get_state_vm\n");
+       return -1;
+    }
+
+    numcores = core->num_vcores > vm->num_cores ? vm->num_cores : core->num_vcores;
+    numregions = mem->num_regions > vm->mem_map.num_base_regions ? vm->mem_map.num_base_regions : mem->num_regions;
+
     switch (vm->run_state) { 
        case VM_INVALID: base->state = V3_VM_INVALID; break;
        case VM_RUNNING: base->state = V3_VM_RUNNING; break;
@@ -882,22 +925,38 @@ int v3_get_state_vm(struct v3_vm_info        *vm,
 #include <palacios/vmm_checkpoint.h>
 
 int v3_save_vm(struct v3_vm_info * vm, char * store, char * url, v3_chkpt_options_t opts) {
-  return v3_chkpt_save_vm(vm, store, url, opts);
+    if (!vm || !store || !url) {
+       PrintError(VM_NONE,VCORE_NONE, "Incorrect arguemnts for v3_save_vm\n");
+       return -1;
+    }
+    return v3_chkpt_save_vm(vm, store, url, opts);
 }
 
 
 int v3_load_vm(struct v3_vm_info * vm, char * store, char * url, v3_chkpt_options_t opts) {
-  return v3_chkpt_load_vm(vm, store, url, opts);
+    if (!vm || !store || !url) {
+       PrintError(VM_NONE,VCORE_NONE, "Incorrect arguemnts for v3_load_vm\n");
+       return -1;
+    }
+    return v3_chkpt_load_vm(vm, store, url, opts);
 }
 
 #ifdef V3_CONFIG_LIVE_MIGRATION
 int v3_send_vm(struct v3_vm_info * vm, char * store, char * url, v3_chkpt_options_t opts) {
-  return v3_chkpt_send_vm(vm, store, url, opts);
+    if (!vm || !store || !url) {
+       PrintError(VM_NONE,VCORE_NONE, "Incorrect arguemnts for v3_send_vm\n");
+       return -1;
+    }
+    return v3_chkpt_send_vm(vm, store, url, opts);
 }
 
 
 int v3_receive_vm(struct v3_vm_info * vm, char * store, char * url, v3_chkpt_options_t opts) {
-  return v3_chkpt_receive_vm(vm, store, url, opts);
+    if (!vm || !store || !url) {
+       PrintError(VM_NONE,VCORE_NONE, "Incorrect arguemnts for v3_receive_vm\n");
+       return -1;
+    }
+    return v3_chkpt_receive_vm(vm, store, url, opts);
 }
 #endif
 
@@ -908,6 +967,11 @@ int v3_free_vm(struct v3_vm_info * vm) {
     int i = 0;
     // deinitialize guest (free memory, etc...)
 
+    if (!vm) { 
+        PrintError(VM_NONE, VCORE_NONE, "Asked to free nonexistent VM\n");
+       return -1;
+    }
+
     if ((vm->run_state != VM_STOPPED) &&
        (vm->run_state != VM_ERROR)) {
        PrintError(vm, VCORE_NONE,"Tried to Free VM in invalid runstate (%d)\n", vm->run_state);

diff --git a/palacios/src/palacios/vmm_direct_paging.c b/palacios/src/palacios/vmm_direct_paging.c
index f313e8d..2884923 100644 (file)
--- a/palacios/src/palacios/vmm_direct_paging.c
+++ b/palacios/src/palacios/vmm_direct_paging.c
@@ -200,7 +200,9 @@ int v3_free_passthrough_pts(struct guest_info * core) {
        case LONG:
        case LONG_32_COMPAT:
            // Long mode will only use 32PAE page tables...
-           delete_page_tables_32pae((pdpe32pae_t *)V3_VAddr((void *)(core->direct_map_pt)));
+           if (core->direct_map_pt) { 
+               delete_page_tables_32pae((pdpe32pae_t *)V3_VAddr((void *)(core->direct_map_pt))); 
+           }
            break;
        default:
            PrintError(core->vm_info, core, "Unknown CPU Mode\n");