Palacios Public Git Repository

To checkout Palacios execute

  git clone http://v3vee.org/palacios/palacios.web/palacios.git
This will give you the master branch. You probably want the devel branch or one of the release branches. To switch to the devel branch, simply execute
  cd palacios
  git checkout --track -b devel origin/devel
The other branches are similar.


added device checkpoint hooks
[palacios.git] / palacios / src / palacios / vmm_dev_mgr.c
index daea57c..e6fad69 100644 (file)
-/* (c) 2008, Jack Lange <jarusl@cs.northwestern.edu> */
-/* (c) 2008, The V3VEE Project <http://www.v3vee.org> */
+/* 
+ * This file is part of the Palacios Virtual Machine Monitor developed
+ * by the V3VEE Project with funding from the United States National 
+ * Science Foundation and the Department of Energy.  
+ *
+ * The V3VEE Project is a joint project between Northwestern University
+ * and the University of New Mexico.  You can find out more at 
+ * http://www.v3vee.org
+ *
+ * Copyright (c) 2008, Jack Lange <jarusl@cs.northwestern.edu> 
+ * Copyright (c) 2008, The V3VEE Project <http://www.v3vee.org> 
+ * All rights reserved.
+ *
+ * Author: Jack Lange <jarusl@cs.northwestern.edu>
+ *
+ * This is free software.  You are permitted to use,
+ * redistribute, and modify it as specified in the file "V3VEE_LICENSE".
+ */
 
-
-#include <palacios/vm_dev.h>
 #include <palacios/vmm_dev_mgr.h>
 #include <palacios/vm_guest.h>
 #include <palacios/vmm.h>
 #include <palacios/vmm_decoder.h>
 
+#ifdef V3_CONFIG_CHECKPOINT
+#include <palacios/vmm_checkpoint.h>
+#endif
 
 
-#ifndef NULL
-#define NULL 0
+#ifndef V3_CONFIG_DEBUG_DEV_MGR
+#undef PrintDebug
+#define PrintDebug(fmt, args...)
 #endif
 
-int dev_mgr_init(struct guest_info * info) {
-  struct vmm_dev_mgr * mgr = &(info->dev_mgr);
-  INIT_LIST_HEAD(&(mgr->dev_list));
-  mgr->num_devs = 0;
 
-  INIT_LIST_HEAD(&(mgr->io_hooks));
-  mgr->num_io_hooks = 0;
+static struct hashtable * master_dev_table = NULL;
 
-  return 0;
+static uint_t dev_hash_fn(addr_t key) {
+    char * name = (char *)key;
+    return v3_hash_buffer((uchar_t *)name, strlen(name));
 }
 
+static int dev_eq_fn(addr_t key1, addr_t key2) {
+    char * name1 = (char *)key1;
+    char * name2 = (char *)key2;
+    
+    return (strcmp(name1, name2) == 0);
+}
 
-int dev_mgr_deinit(struct guest_info * info) {
-  struct vm_device * dev;
-  struct vmm_dev_mgr * mgr = &(info->dev_mgr);
 
-  list_for_each_entry(dev, &(mgr->dev_list), dev_link) {
-    v3_unattach_device(dev);
-    free_device(dev);
-  }
+int V3_init_devices() {
+    extern struct v3_device_info __start__v3_devices[];
+    extern struct v3_device_info __stop__v3_devices[];
+    struct v3_device_info * tmp_dev =  __start__v3_devices;
+    int i = 0;
 
-  return 0;
-}
+#ifdef V3_CONFIG_DEBUG_DEV_MGR
+    {
+       int num_devices = (__stop__v3_devices - __start__v3_devices) / sizeof(struct v3_device_info);
+       PrintDebug("%d Virtual devices registered with Palacios\n", num_devices);
+    }
+#endif
+
+    PrintDebug("Start addres=%p, Stop address=%p\n", __start__v3_devices, __stop__v3_devices);
+
+    master_dev_table = v3_create_htable(0, dev_hash_fn, dev_eq_fn);
 
 
 
+    while (tmp_dev != __stop__v3_devices) {
+       PrintDebug("Device: %s\n", tmp_dev->name);
 
-static int dev_mgr_add_device(struct vmm_dev_mgr * mgr, struct vm_device * dev) {
-  list_add(&(dev->dev_link), &(mgr->dev_list));
-  mgr->num_devs++;
+       if (v3_htable_search(master_dev_table, (addr_t)(tmp_dev->name))) {
+           PrintError("Multiple instance of device (%s)\n", tmp_dev->name);
+           return -1;
+       }
+
+       if (v3_htable_insert(master_dev_table, 
+                            (addr_t)(tmp_dev->name), 
+                            (addr_t)(tmp_dev->init)) == 0) {
+           PrintError("Could not add device %s to master list\n", tmp_dev->name);
+           return -1;
+       }
+
+       tmp_dev = &(__start__v3_devices[++i]);
+    }
 
-  return 0;
+
+    return 0;
 }
 
-static int dev_mgr_remove_device(struct vmm_dev_mgr * mgr, struct vm_device * dev) {
-  list_del(&(dev->dev_link));
-  mgr->num_devs--;
 
-  return 0;
+int V3_deinit_devices() {    
+    v3_free_htable(master_dev_table, 0, 0);
+    return 0;
 }
 
 
+int v3_init_dev_mgr(struct v3_vm_info * vm) {
+    struct vmm_dev_mgr * mgr = &(vm->dev_mgr);
+
+    INIT_LIST_HEAD(&(mgr->dev_list));
+    mgr->num_devs = 0;
+
+    mgr->dev_table = v3_create_htable(0, dev_hash_fn, dev_eq_fn);
 
-/* IO HOOKS */
-int dev_mgr_add_io_hook(struct vmm_dev_mgr * mgr, struct dev_io_hook * hook) {
-  list_add(&(hook->mgr_list), &(mgr->io_hooks));
-  mgr->num_io_hooks++;
-  return 0;
+    INIT_LIST_HEAD(&(mgr->blk_list));
+    INIT_LIST_HEAD(&(mgr->net_list));
+    INIT_LIST_HEAD(&(mgr->char_list));
+    INIT_LIST_HEAD(&(mgr->cons_list));
+
+    mgr->blk_table = v3_create_htable(0, dev_hash_fn, dev_eq_fn);
+    mgr->net_table = v3_create_htable(0, dev_hash_fn, dev_eq_fn);
+    mgr->char_table = v3_create_htable(0, dev_hash_fn, dev_eq_fn);
+    mgr->cons_table = v3_create_htable(0, dev_hash_fn, dev_eq_fn);
+    
+    return 0;
 }
 
 
-int dev_mgr_remove_io_hook(struct vmm_dev_mgr * mgr, struct dev_io_hook * hook) {
-  list_del(&(hook->mgr_list));
-  mgr->num_io_hooks--;
+int v3_free_vm_devices(struct v3_vm_info * vm) {
+    struct vmm_dev_mgr * mgr = &(vm->dev_mgr);
+    struct vm_device * dev;
+    struct vm_device * tmp;
 
-  return 0;
+    list_for_each_entry_safe(dev, tmp, &(mgr->dev_list), dev_link) {
+       v3_remove_device(dev);
+    }
+
+    return 0;
 }
 
+#ifdef V3_CONFIG_CHECKPOINT
+
+int v3_save_vm_devices(struct v3_vm_info * vm, struct v3_chkpt * chkpt) {
+    struct vmm_dev_mgr * mgr = &(vm->dev_mgr);
+    struct vm_device * dev;
+    struct v3_chkpt_ctx * dev_mgr_ctx = NULL;
 
-int dev_add_io_hook(struct vm_device * dev, struct dev_io_hook * hook) {
-  list_add(&(hook->dev_list), &(dev->io_hooks));
-  dev->num_io_hooks++;
-  return 0;
+    uint32_t num_saved_devs = 0;
+    uint32_t table_len = mgr->num_devs * 32;
+    char * name_table = NULL;
+    uint32_t tbl_offset = 0;
+    
+    name_table = V3_Malloc(table_len);
+
+    memset(name_table, 0, table_len);
+    
+
+    dev_mgr_ctx = v3_chkpt_open_ctx(chkpt, NULL, "devices");
+
+    list_for_each_entry(dev, &(mgr->dev_list), dev_link) {
+
+       if (dev->ops->save) {
+           struct v3_chkpt_ctx * dev_ctx = NULL;
+
+           
+           dev_ctx = v3_chkpt_open_ctx(chkpt, dev_mgr_ctx, dev->name);
+
+           dev->ops->save(dev_ctx, dev->private_data);
+
+           v3_chkpt_close_ctx(dev_ctx);
+
+           // Error checking?? 
+
+           strncpy(name_table + tbl_offset, dev->name, 32);
+           tbl_offset += 32;
+           num_saved_devs++;
+       } else {
+           PrintError("Error: %s save() not implemented\n",  dev->name);
+       }
+    }
+
+    
+    // Specify which devices were saved
+    v3_chkpt_save(dev_mgr_ctx, "num_devs", 4, &num_saved_devs); 
+    v3_chkpt_save(dev_mgr_ctx, "names", table_len, name_table);
+    V3_Free(name_table);
+
+    v3_chkpt_close_ctx(dev_mgr_ctx);
+    
+    return 0;
 }
 
 
-int dev_remove_io_hook(struct vm_device * dev, struct dev_io_hook * hook) {
-  list_del(&(hook->dev_list));
-  dev->num_io_hooks--;
+int v3_load_vm_devices(struct v3_vm_info * vm, struct v3_chkpt * chkpt) {
+
+    PrintError("TODO... \n");
 
-  return 0;
+    // Read devices from checkpoint data
+    // selectively load them
+
+    return 0;
 }
 
 
+#endif
 
+static int free_frontends(struct v3_vm_info * vm, struct vmm_dev_mgr * mgr);
 
+int v3_deinit_dev_mgr(struct v3_vm_info * vm) {
+    struct vmm_dev_mgr * mgr = &(vm->dev_mgr);
+    
+    // clear frontend lists
 
-struct dev_io_hook * dev_mgr_find_io_hook(struct vmm_dev_mgr * mgr, ushort_t port) {
-  struct dev_io_hook * tmp;
+    free_frontends(vm, mgr);
+
+
+
+    v3_free_htable(mgr->dev_table, 0, 0);
+
+    return 0;
+}
 
-  list_for_each_entry(tmp, &(mgr->io_hooks), mgr_list) {
-    if (tmp->port == port) {
-      return tmp;
+
+
+int v3_create_device(struct v3_vm_info * vm, const char * dev_name, v3_cfg_tree_t * cfg) {
+    int (*dev_init)(struct v3_vm_info * vm, void * cfg_data);
+
+    dev_init = (void *)v3_htable_search(master_dev_table, (addr_t)dev_name);
+
+    if (dev_init == NULL) {
+       PrintError("Could not find device %s in master device table\n", dev_name);
+       return -1;
     }
-  }
-  return NULL;
+
+
+    if (dev_init(vm, cfg) == -1) {
+       PrintError("Could not initialize Device %s\n", dev_name);
+       return -1;
+    }
+
+    return 0;
 }
 
-struct dev_io_hook * dev_find_io_hook(struct vm_device * dev, ushort_t port) {
-  struct dev_io_hook * tmp;
 
-  list_for_each_entry(tmp, &(dev->io_hooks), dev_list) {
-    if (tmp->port == port) {
-      return tmp;
+
+
+struct vm_device * v3_find_dev(struct v3_vm_info * vm, const char * dev_name) {
+    struct vmm_dev_mgr * mgr = &(vm->dev_mgr);
+
+    if (!dev_name) {
+       return NULL;
     }
-  }
-  return NULL;
+
+    return (struct vm_device *)v3_htable_search(mgr->dev_table, (addr_t)dev_name);
 }
 
 
+/****************************************************************/
+/* The remaining functions are called by the devices themselves */
+/****************************************************************/
+
+typedef enum {DEV_IO_HOOK, DEV_MSR_HOOK, DEV_CPUID_HOOK, DEV_MEM_HOOK, DEV_HCALL_HOOK} dev_rsrc_type_t;
+
+struct dev_rsrc {
+    dev_rsrc_type_t type;
+    uint64_t rsrc;
+
+    struct list_head node;
+};
+
+
+
+static int add_resource(struct vm_device * dev, dev_rsrc_type_t type, uint64_t rsrc_id) {
+    struct dev_rsrc * resource = NULL;
+
+    resource = V3_Malloc(sizeof(struct dev_rsrc));
+
+    if (resource == NULL) {
+       PrintError("Error: Could not allocate device resource\n");
+       return -1;
+    }
+
+    resource->rsrc = rsrc_id;
+    resource->type = type;
+
+    list_add(&(resource->node), &(dev->res_hooks));
+    return 0;
+}
+
+static int free_resource(struct vm_device * dev, dev_rsrc_type_t type, uint64_t rsrc_id) {
+    struct dev_rsrc * resource = NULL;
+    struct dev_rsrc * tmp;
 
+    list_for_each_entry_safe(resource, tmp, &(dev->res_hooks), node) {
+       if ((resource->type == type) && 
+           (resource->rsrc == rsrc_id)) {
 
-int dev_hook_io(struct vm_device   *dev,
-               ushort_t            port,
-               int (*read)(ushort_t port, void * dst, uint_t length, struct vm_device * dev),
-               int (*write)(ushort_t port, void * src, uint_t length, struct vm_device * dev)) {
+           list_del(&(resource->node));
+           V3_Free(resource);
+           
+           return 0;
+       }
+    }
 
-  struct dev_io_hook *hook = (struct dev_io_hook *)V3_Malloc(sizeof(struct dev_io_hook));
-  
-  if (!hook) { 
     return -1;
-  }
+}
 
 
-  if (v3_hook_io_port(dev->vm, port, 
-                     (int (*)(ushort_t, void *, uint_t, void *))read, 
-                     (int (*)(ushort_t, void *, uint_t, void *))write, 
-                     (void *)dev) == 0) {
+int v3_dev_hook_io(struct vm_device * dev, uint16_t port,
+                  int (*read)(struct guest_info * core, uint16_t port, void * dst, uint_t length, void * priv_data),
+                  int (*write)(struct guest_info * core, uint16_t port, void * src, uint_t length, void * priv_data)) {
+    int ret = 0;
+    
+    ret = v3_hook_io_port(dev->vm, port, 
+                         (int (*)(struct guest_info * core, uint16_t, void *, uint_t, void *))read, 
+                         (int (*)(struct guest_info * core, uint16_t, void *, uint_t, void *))write, 
+                         (void *)dev->private_data);
 
-    hook->dev = dev;
-    hook->port = port;
-    hook->read = read;
-    hook->write = write;
+    if (ret == -1) {
+       return -1;
+    }
+
+    if (add_resource(dev, DEV_IO_HOOK, port) == -1) {
+       v3_unhook_io_port(dev->vm, port);
+       PrintError("Could not allocate io hook dev state\n");
+       return -1;
+    }
     
-    dev_mgr_add_io_hook(&(dev->vm->dev_mgr), hook);
-    dev_add_io_hook(dev, hook);
-  } else {
+    return 0;
+}
+
+
+int v3_dev_unhook_io(struct vm_device * dev, uint16_t port) {
+    if (free_resource(dev, DEV_IO_HOOK, port) == 0) {
+       return v3_unhook_io_port(dev->vm, port);           
+    } 
 
     return -1;
-  }
+}
+
+
+int v3_dev_hook_msr(struct vm_device * dev, uint32_t msr,
+                   int (*read)(struct guest_info * core, uint32_t msr, struct v3_msr * dst, void * priv_data),
+                   int (*write)(struct guest_info * core, uint32_t msr, struct v3_msr src, void * priv_data)) {
+    int ret = 0;
+
+    ret = v3_hook_msr(dev->vm, msr, read, write, dev->private_data);
+
+    if (ret == -1) {
+       return -1;
+    }
+
+    if (add_resource(dev, DEV_MSR_HOOK, msr) == -1) {
+       v3_unhook_msr(dev->vm, msr);
+       return -1;
+    }
+
+    return 0;
+}
+                 
+int v3_dev_unhook_msr(struct vm_device * dev, uint32_t msr) {
+    if (free_resource(dev, DEV_MSR_HOOK, msr) == 0) {
+       return v3_unhook_msr(dev->vm, msr);
+    }
 
-  return 0;
+    return -1;
 }
 
 
-int dev_unhook_io(struct vm_device   *dev,
-                 ushort_t            port) {
 
-  struct vmm_dev_mgr * mgr = &(dev->vm->dev_mgr);
-  struct dev_io_hook * hook = dev_mgr_find_io_hook(mgr, port);
 
-  if (!hook) { 
+int v3_remove_device(struct vm_device * dev) {
+    struct vmm_dev_mgr * mgr = &(dev->vm->dev_mgr);
+    struct dev_rsrc * resource = NULL;
+    struct dev_rsrc * tmp;
+
+    list_for_each_entry_safe(resource, tmp, &(dev->res_hooks), node) {
+       if (resource->type == DEV_IO_HOOK) {
+           v3_unhook_io_port(dev->vm, (uint16_t)(resource->rsrc));
+       } else if (resource->type == DEV_MSR_HOOK) {
+           v3_unhook_msr(dev->vm, (uint32_t)(resource->rsrc));
+       }
+
+       list_del(&(resource->node));
+       V3_Free(resource);    
+    }
+
+    if (dev->ops->free) {
+       dev->ops->free(dev->private_data);
+    } else {
+       PrintError("Error: %s free() not implemented\n",  dev->name);
+    }
+
+    list_del(&(dev->dev_link));
+    mgr->num_devs--;
+
+    dev->vm = NULL;
+
+    V3_Free(dev);
     return -1;
-  }
+}
+
 
-  dev_mgr_remove_io_hook(mgr, hook);
-  dev_remove_io_hook(dev, hook);
+struct vm_device * v3_add_device(struct v3_vm_info * vm,
+                                char * name, 
+                                struct v3_device_ops * ops, 
+                                void * private_data) {
+    struct vmm_dev_mgr * mgr = &(vm->dev_mgr);
+    struct vm_device * dev = NULL;
 
-  return v3_unhook_io_port(dev->vm, port);
+    dev = (struct vm_device *)V3_Malloc(sizeof(struct vm_device));
+
+    if (dev == NULL) {
+       return NULL;
+    }
+
+    INIT_LIST_HEAD(&(dev->res_hooks));
+
+    strncpy(dev->name, name, 32);
+    dev->ops = ops;
+    dev->private_data = private_data;
+
+    dev->vm = vm;
+
+    list_add(&(dev->dev_link), &(mgr->dev_list));
+    mgr->num_devs++;
+
+    v3_htable_insert(mgr->dev_table, (addr_t)(dev->name), (addr_t)dev);
+
+    return dev;
 }
 
 
-int v3_attach_device(struct guest_info * vm, struct vm_device * dev) {
-  struct vmm_dev_mgr *mgr= &(vm->dev_mgr);
-  
-  dev->vm = vm;
-  dev_mgr_add_device(mgr, dev);
-  dev->ops->init(dev);
+void v3_print_dev_mgr(struct v3_vm_info * vm) {
+    struct vmm_dev_mgr * mgr = &(vm->dev_mgr);
+    struct vm_device * dev;
+
+    V3_Print("%d devices registered with manager\n", mgr->num_devs);
+
+    list_for_each_entry(dev, &(mgr->dev_list), dev_link) {
+       V3_Print("Device: %s\n", dev->name);
+    }
 
-  return 0;
+    return;
 }
 
-int v3_unattach_device(struct vm_device * dev) {
-  struct vmm_dev_mgr * mgr = &(dev->vm->dev_mgr);
 
-  dev->ops->deinit(dev);
-  dev_mgr_remove_device(mgr, dev);
-  dev->vm = NULL;
 
-  return 0;
+
+struct blk_frontend {
+    int (*connect)(struct v3_vm_info * vm, 
+                   void * frontend_data, 
+                   struct v3_dev_blk_ops * ops, 
+                   v3_cfg_tree_t * cfg, 
+                   void * priv_data);
+       
+
+    struct list_head blk_node;
+
+    void * priv_data;
+};
+
+
+
+int v3_dev_add_blk_frontend(struct v3_vm_info * vm, 
+                           char * name, 
+                           int (*connect)(struct v3_vm_info * vm, 
+                                           void * frontend_data, 
+                                           struct v3_dev_blk_ops * ops, 
+                                           v3_cfg_tree_t * cfg, 
+                                           void * priv_data), 
+                           void * priv_data) {
+
+    struct blk_frontend * frontend = NULL;
+
+    frontend = (struct blk_frontend *)V3_Malloc(sizeof(struct blk_frontend));
+    memset(frontend, 0, sizeof(struct blk_frontend));
+    
+    frontend->connect = connect;
+    frontend->priv_data = priv_data;
+       
+    list_add(&(frontend->blk_node), &(vm->dev_mgr.blk_list));
+    v3_htable_insert(vm->dev_mgr.blk_table, (addr_t)(name), (addr_t)frontend);
+
+    return 0;
 }
 
+int v3_dev_connect_blk(struct v3_vm_info * vm, 
+                      char * frontend_name, 
+                      struct v3_dev_blk_ops * ops, 
+                      v3_cfg_tree_t * cfg, 
+                      void * private_data) {
+
+    struct blk_frontend * frontend = NULL;
 
+    frontend = (struct blk_frontend *)v3_htable_search(vm->dev_mgr.blk_table,
+                                                      (addr_t)frontend_name);
+    
+    if (frontend == NULL) {
+       PrintError("Could not find frontend blk device %s\n", frontend_name);
+       return 0;
+    }
 
+    if (frontend->connect(vm, frontend->priv_data, ops, cfg, private_data) == -1) {
+       PrintError("Error connecting to block frontend %s\n", frontend_name);
+       return -1;
+    }
 
+    return 0;
+}
 
-int dev_mgr_hook_mem(struct guest_info    *vm,
-                    struct vm_device   *device,
-                    void               *start,
-                    void               *end)
-{
 
-  struct dev_mem_hook * hook = (struct dev_mem_hook*)V3_Malloc(sizeof(struct dev_mem_hook));
-  //  V3_Malloc(struct dev_mem_hook *, hook,sizeof(struct dev_mem_hook));
 
-  if (!hook) { 
-    return -1;
-  }
+struct net_frontend {
+    int (*connect)(struct v3_vm_info * vm, 
+                   void * frontend_data, 
+                   struct v3_dev_net_ops * ops, 
+                   v3_cfg_tree_t * cfg, 
+                   void * priv_data);
+    
 
-  /* not implemented yet
-  hook_memory(vm->mem_map, 
-             guest_physical_address_start, 
-             guest_physical_address_end, 
-             read,
-             write,
-             device);
+    struct list_head net_node;
 
-  */
+    void * priv_data;
+};
 
-  return -1;   // remove when hook_memory works
 
+int v3_dev_add_net_frontend(struct v3_vm_info * vm, 
+                           char * name, 
+                           int (*connect)(struct v3_vm_info * vm, 
+                                           void * frontend_data, 
+                                           struct v3_dev_net_ops * ops, 
+                                           v3_cfg_tree_t * cfg, 
+                                           void * private_data), 
+                           void * priv_data)
+{
+    struct net_frontend * frontend = NULL;
 
-  hook->addr_start = start;
-  hook->addr_end = end;
+    frontend = (struct net_frontend *)V3_Malloc(sizeof(struct net_frontend));
+    memset(frontend, 0, sizeof(struct net_frontend));
+    
+    frontend->connect = connect;
+    frontend->priv_data = priv_data;
+       
+    list_add(&(frontend->net_node), &(vm->dev_mgr.net_list));
+    v3_htable_insert(vm->dev_mgr.net_table, (addr_t)(name), (addr_t)frontend);
 
-  return 0;
-  
+    return 0;
 }
 
 
-int dev_mgr_unhook_mem(struct vm_device   *dev,
-                      addr_t start,
-                      addr_t end)  {
-  /*
-  struct vmm_dev_mgr * mgr = &(dev->vm->dev_mgr);
-  struct dev_mem_hook *hook = dev_mgr_find_mem_hook(mgr, start, end);
-  
-  if (!hook) { 
-    // Very bad - unhooking something that doesn't exist!
-    return -1;
-  }
-  */
+int v3_dev_connect_net(struct v3_vm_info * vm, 
+                      char * frontend_name, 
+                      struct v3_dev_net_ops * ops, 
+                      v3_cfg_tree_t * cfg, 
+                      void * private_data)
+{
+    struct net_frontend * frontend = NULL;
 
-  /* not implemented yet
-  return unhook_mem_port(vm->mem_map,
-                        guest_physical_start,
-                        guest_physical_end) ;
+    frontend = (struct net_frontend *)v3_htable_search(vm->dev_mgr.net_table,
+                                                      (addr_t)frontend_name);
+    
+    if (frontend == NULL) {
+       PrintError("Could not find frontend net device %s\n", frontend_name);
+       return 0;
+    }
+
+    if (frontend->connect(vm, frontend->priv_data, ops, cfg, private_data) == -1) {
+       PrintError("Error connecting to net frontend %s\n", frontend_name);
+       return -1;
+    }
 
-  */
-  return -1;
+    return 0;
 }
 
 
+struct cons_frontend {
+    int (*connect)(struct v3_vm_info * vm, 
+                  void * frontend_data, 
+                  struct v3_dev_console_ops * ops, 
+                  v3_cfg_tree_t * cfg, 
+                  void * priv_data);
+    
+
+    struct list_head cons_node;
+
+    void * priv_data;
+};
+
+int v3_dev_add_console_frontend(struct v3_vm_info * vm, 
+                               char * name, 
+                               int (*connect)(struct v3_vm_info * vm, 
+                                              void * frontend_data, 
+                                              struct v3_dev_console_ops * ops, 
+                                              v3_cfg_tree_t * cfg, 
+                                              void * private_data), 
+                               void * priv_data)
+{
+    struct cons_frontend * frontend = NULL;
+
+    frontend = (struct cons_frontend *)V3_Malloc(sizeof(struct cons_frontend));
+    memset(frontend, 0, sizeof(struct cons_frontend));
+    
+    frontend->connect = connect;
+    frontend->priv_data = priv_data;
+       
+    list_add(&(frontend->cons_node), &(vm->dev_mgr.cons_list));
+    v3_htable_insert(vm->dev_mgr.cons_table, (addr_t)(name), (addr_t)frontend);
+
+    return 0;
+}
 
 
-void PrintDebugDevMgr(struct guest_info * info) {
-  struct vmm_dev_mgr * mgr = &(info->dev_mgr);
-  struct vm_device * dev;
-  PrintDebug("%d devices registered with manager\n", mgr->num_devs);
+int v3_dev_connect_console(struct v3_vm_info * vm, 
+                          char * frontend_name, 
+                          struct v3_dev_console_ops * ops, 
+                          v3_cfg_tree_t * cfg, 
+                          void * private_data)
+{
+    struct cons_frontend * frontend = NULL;
 
-  list_for_each_entry(dev, &(mgr->dev_list), dev_link) {
-    PrintDebugDev(dev);
-    PrintDebug("next..\n");
-  }
+    frontend = (struct cons_frontend *)v3_htable_search(vm->dev_mgr.cons_table,
+                                                       (addr_t)frontend_name);
+    
+    if (frontend == NULL) {
+       PrintError("Could not find frontend console device %s\n", frontend_name);
+       return 0;
+    }
+    
+    if (frontend->connect(vm, frontend->priv_data, ops, cfg, private_data) == -1) {
+       PrintError("Error connecting to console frontend %s\n", frontend_name);
+       return -1;
+    }
 
-  return;
+    return 0;
 }
 
+struct char_frontend {
+    int (*connect)(struct v3_vm_info * vm, 
+                  void * frontend_data, 
+                  struct v3_dev_char_ops * ops, 
+                  v3_cfg_tree_t * cfg, 
+                  void * priv_data, 
+                  void ** push_fn_arg);
+    
+
+    struct list_head char_node;
+
+    void * priv_data;
+};
+
+int v3_dev_add_char_frontend(struct v3_vm_info * vm, 
+                            char * name, 
+                            int (*connect)(struct v3_vm_info * vm, 
+                                           void * frontend_data, 
+                                           struct v3_dev_char_ops * ops, 
+                                           v3_cfg_tree_t * cfg, 
+                                           void * private_data, 
+                                           void ** push_fn_arg), 
+                            void * priv_data)
+{
+    struct char_frontend * frontend = NULL;
+
+    frontend = (struct char_frontend *)V3_Malloc(sizeof(struct char_frontend));
+    memset(frontend, 0, sizeof(struct char_frontend));
+    
+    frontend->connect = connect;
+    frontend->priv_data = priv_data;
+       
+    list_add(&(frontend->char_node), &(vm->dev_mgr.char_list));
+    v3_htable_insert(vm->dev_mgr.char_table, (addr_t)(name), (addr_t)frontend);
 
-void PrintDebugDev(struct vm_device * dev) {
-  
-  PrintDebug("Device: %s\n", dev->name);
-  PrintDebugDevIO(dev);
+    return 0;
 }
 
-void PrintDebugDevMgrIO(struct vmm_dev_mgr * mgr) {
 
+int v3_dev_connect_char(struct v3_vm_info * vm, 
+                       char * frontend_name, 
+                       struct v3_dev_char_ops * ops, 
+                       v3_cfg_tree_t * cfg, 
+                       void * private_data, 
+                       void ** push_fn_arg)
+{
+    struct char_frontend * frontend = NULL;
+
+    frontend = (struct char_frontend *)v3_htable_search(vm->dev_mgr.char_table,
+                                                       (addr_t)frontend_name);
+    
+    if (frontend == NULL) {
+       PrintError("Could not find frontend char device %s\n", frontend_name);
+       return 0;
+    }
+    
+    if (frontend->connect(vm, frontend->priv_data, ops, cfg, private_data, push_fn_arg) == -1) {
+       PrintError("Error connecting to char frontend %s\n", frontend_name);
+       return -1;
+    }
+
+    return 0;
 }
 
-void PrintDebugDevIO(struct vm_device * dev) {
-  struct dev_io_hook * hook;
 
-  PrintDebug("IO Hooks(%d)  for Device: %s\n", dev->num_io_hooks,  dev->name);
 
-  list_for_each_entry(hook, &(dev->io_hooks), dev_list) {
-    PrintDebug("\tPort: 0x%x (read=0x%x), (write=0x%x)\n", hook->port, hook->read, hook->write);
-  }
+static int free_frontends(struct v3_vm_info * vm, struct vmm_dev_mgr * mgr) {
+    struct char_frontend * chr = NULL;
+    struct char_frontend * tmp_chr = NULL;
+    struct cons_frontend * cons = NULL;
+    struct cons_frontend * tmp_cons = NULL;
+    struct net_frontend * net = NULL;
+    struct net_frontend * tmp_net = NULL;
+    struct blk_frontend * blk = NULL;
+    struct blk_frontend * tmp_blk = NULL;
+
+
+
+    list_for_each_entry_safe(chr, tmp_chr, &(mgr->char_list), char_node) {
+       list_del(&(chr->char_node));
+       V3_Free(chr);
+    }
+
+    list_for_each_entry_safe(cons, tmp_cons, &(mgr->cons_list), cons_node) {
+       list_del(&(cons->cons_node));
+       V3_Free(cons);
+    }
+
+    list_for_each_entry_safe(net, tmp_net, &(mgr->net_list), net_node) {
+       list_del(&(net->net_node));
+       V3_Free(net);
+    }
+
+    list_for_each_entry_safe(blk, tmp_blk, &(mgr->blk_list), blk_node) {
+       list_del(&(blk->blk_node));
+       V3_Free(blk);
+    }
+
+    v3_free_htable(mgr->blk_table, 0, 0);
+    v3_free_htable(mgr->net_table, 0, 0);
+    v3_free_htable(mgr->char_table, 0, 0);
+    v3_free_htable(mgr->cons_table, 0, 0);
+
 
-  return;
+    return 0;
 }