Checkpointing and migration now support options, the first of which are: skipping...

diff --git a/linux_module/palacios.h b/linux_module/palacios.h
index 99ef5ef..8810f44 100644 (file)
--- a/linux_module/palacios.h
+++ b/linux_module/palacios.h
@@ -70,6 +70,12 @@ struct v3_core_move_cmd {
 struct v3_chkpt_info {
     char store[128];
     char url[256]; /* This might need to be bigger... */
+    unsigned long long opts;
+#define V3_CHKPT_OPT_NONE         0
+#define V3_CHKPT_OPT_SKIP_MEM     1  // don't write memory to store
+#define V3_CHKPT_OPT_SKIP_DEVS    2  // don't write devices to store
+#define V3_CHKPT_OPT_SKIP_CORES   4  // don't write core arch ind data to store
+#define V3_CHKPT_OPT_SKIP_ARCHDEP 8  // don't write core arch dep data to store
 } __attribute__((packed));
 
 

diff --git a/linux_module/vm.c b/linux_module/vm.c
index 54d5efd..b7425e4 100644 (file)
--- a/linux_module/vm.c
+++ b/linux_module/vm.c
@@ -212,7 +212,7 @@ static long v3_vm_ioctl(struct file * filp,
            
            NOTICE("Saving Guest to %s:%s\n", chkpt.store, chkpt.url);
 
-           if (v3_save_vm(guest->v3_ctx, chkpt.store, chkpt.url) == -1) {
+           if (v3_save_vm(guest->v3_ctx, chkpt.store, chkpt.url, chkpt.opts) == -1) {
                WARNING("Error checkpointing VM state\n");
                return -EFAULT;
            }
@@ -232,7 +232,7 @@ static long v3_vm_ioctl(struct file * filp,
            
            NOTICE("Loading Guest from %s:%s\n", chkpt.store, chkpt.url);
 
-           if (v3_load_vm(guest->v3_ctx, chkpt.store, chkpt.url) == -1) {
+           if (v3_load_vm(guest->v3_ctx, chkpt.store, chkpt.url, chkpt.opts) == -1) {
                WARNING("Error Loading VM state\n");
                return -EFAULT;
            }
@@ -256,7 +256,7 @@ static long v3_vm_ioctl(struct file * filp,
            
            NOTICE("Sending (live-migrating) Guest to %s:%s\n",chkpt_info.store, chkpt_info.url); 
            
-           if (v3_send_vm(guest->v3_ctx, chkpt_info.store, chkpt_info.url) == -1) {
+           if (v3_send_vm(guest->v3_ctx, chkpt_info.store, chkpt_info.url, chkpt_info.opts) == -1) {
                WARNING("Error sending VM\n");
                return -EFAULT;
            }
@@ -278,7 +278,7 @@ static long v3_vm_ioctl(struct file * filp,
            
            NOTICE("Receiving (live-migrating) Guest to %s:%s\n",chkpt_info.store, chkpt_info.url);
            
-           if (v3_receive_vm(guest->v3_ctx, chkpt_info.store, chkpt_info.url) == -1) {
+           if (v3_receive_vm(guest->v3_ctx, chkpt_info.store, chkpt_info.url, chkpt_info.opts) == -1) {
                WARNING("Error receiving VM\n");
                return -EFAULT;
            }

diff --git a/linux_usr/v3_ctrl.h b/linux_usr/v3_ctrl.h
index e81968c..929d7e6 100644 (file)
--- a/linux_usr/v3_ctrl.h
+++ b/linux_usr/v3_ctrl.h
@@ -77,6 +77,12 @@ struct v3_debug_cmd {
 struct v3_chkpt_info {
     char store[128];
     char url[256]; /* This might need to be bigger... */
+    unsigned long long opts;
+#define V3_CHKPT_OPT_NONE         0
+#define V3_CHKPT_OPT_SKIP_MEM     1  // don't write memory to store
+#define V3_CHKPT_OPT_SKIP_DEVS    2  // don't write devices to store
+#define V3_CHKPT_OPT_SKIP_CORES   4  // don't write core arch ind data to store
+#define V3_CHKPT_OPT_SKIP_ARCHDEP 8  // don't write core arch dep data to store
 } __attribute__((packed));
 
 

diff --git a/linux_usr/v3_load.c b/linux_usr/v3_load.c
index a409a2d..7e3e212 100644 (file)
--- a/linux_usr/v3_load.c
+++ b/linux_usr/v3_load.c
@@ -32,7 +32,13 @@ int main(int argc, char* argv[]) {
     char * vm_dev = NULL;
 
     if (argc < 4) {
-       printf("usage: v3_load <vm_device> <store> <url>\n");
+       printf("usage: v3_load <vm_device> <store> <url> [optionmask]\n");
+       printf(" optionmask consists of the sum of any of the following\n");
+       printf(" 0    none\n");
+       printf(" 1    skip memory\n");
+       printf(" 2    skip devices\n");
+       printf(" 4    skip cores\n");
+       printf(" 8    skip architecture-specific core state\n");
        return -1;
     }
 
@@ -53,6 +59,12 @@ int main(int argc, char* argv[]) {
 
     strncpy(chkpt.url, argv[3], MAX_URL_LEN);
 
+    if (argc>4) {
+      chkpt.opts = atoll(argv[4]);
+    } else {
+      chkpt.opts = V3_CHKPT_OPT_NONE;
+    }
+
     vm_fd = open(vm_dev, O_RDONLY);
     if (vm_fd == -1) {
        printf("Error opening VM device: %s\n", vm_dev);

diff --git a/linux_usr/v3_receive.c b/linux_usr/v3_receive.c
index 9c3fafd..153ccd9 100644 (file)
--- a/linux_usr/v3_receive.c
+++ b/linux_usr/v3_receive.c
@@ -32,7 +32,13 @@ int main(int argc, char* argv[]) {
     char * vm_dev = NULL;
 
     if (argc < 4) {
-       printf("Usage: ./v3_receive <vm_device> <store> <url>\n");
+       printf("Usage: ./v3_receive <vm_device> <store> <url> [optionmask]\n");
+       printf(" optionmask consists of the sum of any of the following\n");
+       printf(" 0    none\n");
+       printf(" 1    skip memory\n");
+       printf(" 2    skip devices\n");
+       printf(" 4    skip cores\n");
+       printf(" 8    skip architecture-specific core state\n");
        return -1;
     }
 
@@ -53,6 +59,12 @@ int main(int argc, char* argv[]) {
 
     strncpy(chkpt.url, argv[3], MAX_URL_LEN);
 
+    if (argc>4) {
+      chkpt.opts = atoll(argv[4]);
+    } else {
+      chkpt.opts = V3_CHKPT_OPT_NONE;
+    }
+
     vm_fd = open(vm_dev, O_RDONLY);
     if (vm_fd == -1) {
        printf("Error opening VM device: %s\n", vm_dev);

diff --git a/linux_usr/v3_save.c b/linux_usr/v3_save.c
index 46ae513..4749c5a 100644 (file)
--- a/linux_usr/v3_save.c
+++ b/linux_usr/v3_save.c
@@ -31,8 +31,16 @@ int main(int argc, char* argv[]) {
     int vm_fd;
     char * vm_dev = NULL;
 
+    
+
     if (argc < 4) {
-       printf("usage: v3_save <vm_device> <store> <url>\n");
+       printf("usage: v3_save <vm_device> <store> <url> [optionmask]\n");
+       printf(" optionmask consists of the sum of any of the following\n");
+       printf(" 0    none\n");
+       printf(" 1    skip memory\n");
+       printf(" 2    skip devices\n");
+       printf(" 4    skip cores\n");
+       printf(" 8    skip architecture-specific core state\n");
        return -1;
     }
 
@@ -45,7 +53,6 @@ int main(int argc, char* argv[]) {
 
     strncpy(chkpt.store, argv[2], MAX_STORE_LEN);
 
-
     if (strlen(argv[3]) >= MAX_URL_LEN) {
        printf("ERROR: Checkpoint URL longer than maximum size (%d)\n", MAX_URL_LEN);
        return -1;
@@ -53,6 +60,13 @@ int main(int argc, char* argv[]) {
 
     strncpy(chkpt.url, argv[3], MAX_URL_LEN);
 
+    if (argc>4) {
+      chkpt.opts = atoll(argv[4]);
+    } else {
+      chkpt.opts = V3_CHKPT_OPT_NONE;
+    }
+
+
     vm_fd = open(vm_dev, O_RDONLY);
     if (vm_fd == -1) {
        printf("Error opening VM device: %s\n", vm_dev);

diff --git a/linux_usr/v3_send.c b/linux_usr/v3_send.c
index fcb71c4..523be30 100644 (file)
--- a/linux_usr/v3_send.c
+++ b/linux_usr/v3_send.c
@@ -32,7 +32,13 @@ int main(int argc, char* argv[]) {
     char * vm_dev = NULL;
 
     if (argc < 4) {
-       printf("Usage: ./v3_send <vm_device> <store> <url>\n");
+       printf("Usage: ./v3_send <vm_device> <store> <url> [optionmask]\n");
+       printf(" optionmask consists of the sum of any of the following\n");
+       printf(" 0    none\n");
+       printf(" 1    skip memory\n");
+       printf(" 2    skip devices\n");
+       printf(" 4    skip cores\n");
+       printf(" 8    skip architecture-specific core state\n");
        return -1;
     }
 
@@ -53,6 +59,12 @@ int main(int argc, char* argv[]) {
 
     strncpy(chkpt.url, argv[3], MAX_URL_LEN);
 
+    if (argc>4) {
+      chkpt.opts = atoll(argv[4]);
+    } else {
+      chkpt.opts = V3_CHKPT_OPT_NONE;
+    }
+
     vm_fd = open(vm_dev, O_RDONLY);
     if (vm_fd == -1) {
        printf("Error opening VM device: %s\n", vm_dev);

diff --git a/palacios/include/palacios/vmm.h b/palacios/include/palacios/vmm.h
index 083644e..5379928 100644 (file)
--- a/palacios/include/palacios/vmm.h
+++ b/palacios/include/palacios/vmm.h
@@ -386,11 +386,11 @@ int v3_pause_vm(struct v3_vm_info * vm);
 int v3_continue_vm(struct v3_vm_info * vm);
 int v3_simulate_vm(struct v3_vm_info * vm, unsigned int msecs);
 
-int v3_save_vm(struct v3_vm_info * vm, char * store, char * url);
-int v3_load_vm(struct v3_vm_info * vm, char * store, char * url);
+int v3_save_vm(struct v3_vm_info * vm, char * store, char * url, unsigned long long opts);
+int v3_load_vm(struct v3_vm_info * vm, char * store, char * url, unsigned long long opts);
 
-int v3_send_vm(struct v3_vm_info * vm, char * store, char * url);
-int v3_receive_vm(struct v3_vm_info * vm, char * store, char * url);
+int v3_send_vm(struct v3_vm_info * vm, char * store, char * url, unsigned long long opts);
+int v3_receive_vm(struct v3_vm_info * vm, char * store, char * url, unsigned long long opts);
 
 int v3_move_vm_core(struct v3_vm_info * vm, int vcore_id, int target_cpu);
 

diff --git a/palacios/include/palacios/vmm_checkpoint.h b/palacios/include/palacios/vmm_checkpoint.h
index 3b1a06e..8bd5f5a 100644 (file)
--- a/palacios/include/palacios/vmm_checkpoint.h
+++ b/palacios/include/palacios/vmm_checkpoint.h
@@ -156,12 +156,21 @@ int     v3_chkpt_load(struct v3_chkpt_ctx * ctx, char * tag, uint64_t len, void
 struct v3_chkpt_ctx * v3_chkpt_open_ctx(struct v3_chkpt * chkpt, char * name);
 int                   v3_chkpt_close_ctx(struct v3_chkpt_ctx * ctx);
 
-int v3_chkpt_save_vm(struct v3_vm_info * vm, char * store, char * url);
-int v3_chkpt_load_vm(struct v3_vm_info * vm, char * store, char * url);
+
+typedef uint64_t v3_chkpt_options_t;
+// The options are a bitwise or of the following
+#define V3_CHKPT_OPT_NONE         0
+#define V3_CHKPT_OPT_SKIP_MEM     1  // don't write memory to store
+#define V3_CHKPT_OPT_SKIP_DEVS    2  // don't write devices to store
+#define V3_CHKPT_OPT_SKIP_CORES   4  // don't write core arch ind data to store
+#define V3_CHKPT_OPT_SKIP_ARCHDEP 8  // don't write core arch dep data to store
+
+int v3_chkpt_save_vm(struct v3_vm_info * vm, char * store, char * url, v3_chkpt_options_t opts);
+int v3_chkpt_load_vm(struct v3_vm_info * vm, char * store, char * url, v3_chkpt_options_t opts);
 
 #ifdef V3_CONFIG_LIVE_MIGRATION
-int v3_chkpt_send_vm(struct v3_vm_info * vm, char * store, char * url);
-int v3_chkpt_receive_vm(struct v3_vm_info * vm, char * store, char * url);
+int v3_chkpt_send_vm(struct v3_vm_info * vm, char * store, char * url, v3_chkpt_options_t opts);
+int v3_chkpt_receive_vm(struct v3_vm_info * vm, char * store, char * url, v3_chkpt_options_t opts);
 #endif
 
 int V3_init_checkpoint();

diff --git a/palacios/src/palacios/vmm.c b/palacios/src/palacios/vmm.c
index 6e32e88..61aa245 100644 (file)
--- a/palacios/src/palacios/vmm.c
+++ b/palacios/src/palacios/vmm.c
@@ -720,23 +720,23 @@ int v3_get_state_vm(struct v3_vm_info *vm, struct v3_vm_state *s)
 #ifdef V3_CONFIG_CHECKPOINT
 #include <palacios/vmm_checkpoint.h>
 
-int v3_save_vm(struct v3_vm_info * vm, char * store, char * url) {
-    return v3_chkpt_save_vm(vm, store, url);
+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);
 }
 
 
-int v3_load_vm(struct v3_vm_info * vm, char * store, char * url) {
-    return v3_chkpt_load_vm(vm, store, url);
+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);
 }
 
 #ifdef V3_CONFIG_LIVE_MIGRATION
-int v3_send_vm(struct v3_vm_info * vm, char * store, char * url) {
-    return v3_chkpt_send_vm(vm, store, url);
+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);
 }
 
 
-int v3_receive_vm(struct v3_vm_info * vm, char * store, char * url) {
-    return v3_chkpt_receive_vm(vm, store, url);
+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);
 }
 #endif
 

diff --git a/palacios/src/palacios/vmm_checkpoint.c b/palacios/src/palacios/vmm_checkpoint.c
index 9c55e3f..db9f42f 100644 (file)
--- a/palacios/src/palacios/vmm_checkpoint.c
+++ b/palacios/src/palacios/vmm_checkpoint.c
@@ -666,7 +666,7 @@ static int load_header(struct v3_vm_info * vm, struct v3_chkpt * chkpt) {
 }
 
 
-static int load_core(struct guest_info * info, struct v3_chkpt * chkpt) {
+static int load_core(struct guest_info * info, struct v3_chkpt * chkpt, v3_chkpt_options_t opts) {
     extern v3_cpu_arch_t v3_mach_type;
     void * ctx = NULL;
     char key_name[16];
@@ -773,6 +773,10 @@ static int load_core(struct guest_info * info, struct v3_chkpt * chkpt) {
     }
 
 
+    if (opts & V3_CHKPT_OPT_SKIP_ARCHDEP) { 
+      goto donearch;
+    }
+
     switch (v3_mach_type) {
        case V3_SVM_CPU:
        case V3_SVM_REV3_CPU: {
@@ -823,6 +827,8 @@ static int load_core(struct guest_info * info, struct v3_chkpt * chkpt) {
            goto loadfailout;
     }
 
+ donearch:
+
     PrintDebug(info->vm_info, info, "Load of core succeeded\n");
 
     v3_print_guest_state(info);
@@ -838,7 +844,7 @@ static int load_core(struct guest_info * info, struct v3_chkpt * chkpt) {
 
 // GEM5 - Hypercall for initiating transfer to gem5 (checkpoint)
 
-static int save_core(struct guest_info * info, struct v3_chkpt * chkpt) {
+static int save_core(struct guest_info * info, struct v3_chkpt * chkpt, v3_chkpt_options_t opts) {
     extern v3_cpu_arch_t v3_mach_type;
     void * ctx = NULL;
     char key_name[16];
@@ -928,6 +934,10 @@ static int save_core(struct guest_info * info, struct v3_chkpt * chkpt) {
 
     v3_chkpt_close_ctx(ctx); ctx=0;
 
+    if (opts & V3_CHKPT_OPT_SKIP_ARCHDEP) {
+      goto donearch;
+    }
+
     //Architechture specific code
     switch (v3_mach_type) {
        case V3_SVM_CPU:
@@ -979,6 +989,8 @@ static int save_core(struct guest_info * info, struct v3_chkpt * chkpt) {
            goto savefailout;
            
     }
+
+ donearch:
     
     return 0;
 
@@ -993,7 +1005,7 @@ static int save_core(struct guest_info * info, struct v3_chkpt * chkpt) {
 // GEM5 - Madhav has debug code here for printing instrucions
 //
 
-int v3_chkpt_save_vm(struct v3_vm_info * vm, char * store, char * url) {
+int v3_chkpt_save_vm(struct v3_vm_info * vm, char * store, char * url, v3_chkpt_options_t opts) {
     struct v3_chkpt * chkpt = NULL;
     int ret = 0;;
     int i = 0;
@@ -1011,28 +1023,33 @@ int v3_chkpt_save_vm(struct v3_vm_info * vm, char * store, char * url) {
        while (v3_raise_barrier(vm, NULL) == -1);
     }
 
-    if ((ret = save_memory(vm, chkpt)) == -1) {
+    if (!(opts & V3_CHKPT_OPT_SKIP_MEM)) {
+      if ((ret = save_memory(vm, chkpt)) == -1) {
        PrintError(vm, VCORE_NONE, "Unable to save memory\n");
        goto out;
+      }
     }
     
     
-    if ((ret = v3_save_vm_devices(vm, chkpt)) == -1) {
+    if (!(opts & V3_CHKPT_OPT_SKIP_DEVS)) {
+      if ((ret = v3_save_vm_devices(vm, chkpt)) == -1) {
        PrintError(vm, VCORE_NONE, "Unable to save devices\n");
        goto out;
+      }
     }
-    
 
     if ((ret = save_header(vm, chkpt)) == -1) {
        PrintError(vm, VCORE_NONE, "Unable to save header\n");
        goto out;
     }
-    
-    for (i = 0; i < vm->num_cores; i++){
-       if ((ret = save_core(&(vm->cores[i]), chkpt)) == -1) {
-           PrintError(vm, VCORE_NONE, "chkpt of core %d failed\n", i);
-           goto out;
+
+    if (!(opts & V3_CHKPT_OPT_SKIP_CORES)) { 
+      for (i = 0; i < vm->num_cores; i++){
+       if ((ret = save_core(&(vm->cores[i]), chkpt, opts)) == -1) {
+         PrintError(vm, VCORE_NONE, "chkpt of core %d failed\n", i);
+         goto out;
        }
+      }
     }
     
  out:
@@ -1048,7 +1065,7 @@ int v3_chkpt_save_vm(struct v3_vm_info * vm, char * store, char * url) {
 
 }
 
-int v3_chkpt_load_vm(struct v3_vm_info * vm, char * store, char * url) {
+int v3_chkpt_load_vm(struct v3_vm_info * vm, char * store, char * url, v3_chkpt_options_t opts) {
     struct v3_chkpt * chkpt = NULL;
     int i = 0;
     int ret = 0;
@@ -1065,15 +1082,18 @@ int v3_chkpt_load_vm(struct v3_vm_info * vm, char * store, char * url) {
        while (v3_raise_barrier(vm, NULL) == -1);
     }
 
-    if ((ret = load_memory(vm, chkpt)) == -1) {
+    if (!(opts & V3_CHKPT_OPT_SKIP_MEM)) {
+      if ((ret = load_memory(vm, chkpt)) == -1) {
        PrintError(vm, VCORE_NONE, "Unable to load memory\n");
        goto out;
+      }
     }
 
-
-    if ((ret = v3_load_vm_devices(vm, chkpt)) == -1) {
+    if (!(opts & V3_CHKPT_OPT_SKIP_DEVS)) {
+      if ((ret = v3_load_vm_devices(vm, chkpt)) == -1) {
        PrintError(vm, VCORE_NONE, "Unable to load devies\n");
        goto out;
+      }
     }
 
 
@@ -1083,11 +1103,13 @@ int v3_chkpt_load_vm(struct v3_vm_info * vm, char * store, char * url) {
     }
 
     //per core cloning
-    for (i = 0; i < vm->num_cores; i++) {
-       if ((ret = load_core(&(vm->cores[i]), chkpt)) == -1) {
-           PrintError(vm, VCORE_NONE, "Error loading core state (core=%d)\n", i);
-           goto out;
+    if (!(opts & V3_CHKPT_OPT_SKIP_CORES)) {
+      for (i = 0; i < vm->num_cores; i++) {
+       if ((ret = load_core(&(vm->cores[i]), chkpt, opts)) == -1) {
+         PrintError(vm, VCORE_NONE, "Error loading core state (core=%d)\n", i);
+         goto out;
        }
+      }
     }
 
  out:
@@ -1119,7 +1141,7 @@ int v3_chkpt_load_vm(struct v3_vm_info * vm, char * store, char * url) {
 
 
 
-int v3_chkpt_send_vm(struct v3_vm_info * vm, char * store, char * url) {
+int v3_chkpt_send_vm(struct v3_vm_info * vm, char * store, char * url, v3_chkpt_options_t opts) {
     struct v3_chkpt * chkpt = NULL;
     int ret = 0;;
     int iter = 0;
@@ -1133,10 +1155,10 @@ int v3_chkpt_send_vm(struct v3_vm_info * vm, char * store, char * url) {
 
     // Currently will work only for shadow paging
     for (i=0;i<vm->num_cores;i++) { 
-       if (vm->cores[i].shdw_pg_mode!=SHADOW_PAGING) { 
-           PrintError(vm, VCORE_NONE, "Cannot currently handle nested paging\n");
-           return -1;
-       }
+      if (vm->cores[i].shdw_pg_mode!=SHADOW_PAGING && !(opts & V3_CHKPT_OPT_SKIP_MEM)) { 
+       PrintError(vm, VCORE_NONE, "Cannot currently handle nested paging\n");
+       return -1;
+      }
     }
     
     
@@ -1148,6 +1170,10 @@ int v3_chkpt_send_vm(struct v3_vm_info * vm, char * store, char * url) {
        return -1;
     }
     
+    if (opts & V3_CHKPT_OPT_SKIP_MEM) {
+      goto memdone;
+    }
+
     // In a send, the memory is copied incrementally first,
     // followed by the remainder of the state
     
@@ -1244,38 +1270,45 @@ int v3_chkpt_send_vm(struct v3_vm_info * vm, char * store, char * url) {
         ret = -1;
         goto out;
     }
-    
+
+ memdone:    
     // save the non-memory state
-    if ((ret = v3_save_vm_devices(vm, chkpt)) == -1) {
+    if (!(opts & V3_CHKPT_OPT_SKIP_DEVS)) {
+      if ((ret = v3_save_vm_devices(vm, chkpt)) == -1) {
        PrintError(vm, VCORE_NONE, "Unable to save devices\n");
        goto out;
+      }
     }
-    
 
     if ((ret = save_header(vm, chkpt)) == -1) {
        PrintError(vm, VCORE_NONE, "Unable to save header\n");
        goto out;
     }
     
-    for (i = 0; i < vm->num_cores; i++){
-       if ((ret = save_core(&(vm->cores[i]), chkpt)) == -1) {
-           PrintError(vm, VCORE_NONE, "chkpt of core %d failed\n", i);
-           goto out;
+    if (!(opts & V3_CHKPT_OPT_SKIP_CORES)) {
+      for (i = 0; i < vm->num_cores; i++){
+       if ((ret = save_core(&(vm->cores[i]), chkpt, opts)) == -1) {
+         PrintError(vm, VCORE_NONE, "chkpt of core %d failed\n", i);
+         goto out;
        }
+      }
     }
-    
-    stop_time = v3_get_host_time(&(vm->cores[0].time_state));
-    PrintDebug(vm, VCORE_NONE, "num_mod_pages=%d\ndowntime=%llu\n",num_mod_pages,stop_time-start_time);
-    PrintDebug(vm, VCORE_NONE, "Done sending VM!\n"); 
- out:
-    v3_bitmap_deinit(&modified_pages_to_send);
+
+    if (!(opts & V3_CHKPT_OPT_SKIP_MEM)) {
+      stop_time = v3_get_host_time(&(vm->cores[0].time_state));
+      PrintDebug(vm, VCORE_NONE, "num_mod_pages=%d\ndowntime=%llu\n",num_mod_pages,stop_time-start_time);
+      PrintDebug(vm, VCORE_NONE, "Done sending VM!\n"); 
+    out:
+      v3_bitmap_deinit(&modified_pages_to_send);
+    }
+
     chkpt_close(chkpt);
     
     return ret;
 
 }
 
-int v3_chkpt_receive_vm(struct v3_vm_info * vm, char * store, char * url) {
+int v3_chkpt_receive_vm(struct v3_vm_info * vm, char * store, char * url, v3_chkpt_options_t opts) {
     struct v3_chkpt * chkpt = NULL;
     int i = 0;
     int ret = 0;
@@ -1283,10 +1316,10 @@ int v3_chkpt_receive_vm(struct v3_vm_info * vm, char * store, char * url) {
  
     // Currently will work only for shadow paging
     for (i=0;i<vm->num_cores;i++) { 
-       if (vm->cores[i].shdw_pg_mode!=SHADOW_PAGING) { 
-           PrintError(vm, VCORE_NONE, "Cannot currently handle nested paging\n");
-           return -1;
-       }
+      if (vm->cores[i].shdw_pg_mode!=SHADOW_PAGING && !(opts & V3_CHKPT_OPT_SKIP_MEM)) { 
+       PrintError(vm, VCORE_NONE, "Cannot currently handle nested paging\n");
+       return -1;
+      }
     }
     
     chkpt = chkpt_open(vm, store, url, LOAD);
@@ -1297,6 +1330,11 @@ int v3_chkpt_receive_vm(struct v3_vm_info * vm, char * store, char * url) {
        return -1;
     }
     
+
+    if (opts & V3_CHKPT_OPT_SKIP_MEM) { 
+      goto memdone;
+    }
+
     if (v3_bitmap_init(&mod_pgs,vm->mem_size>>12) == -1) {
        chkpt_close(chkpt);
         PrintError(vm, VCORE_NONE, "Could not intialize bitmap.\n");
@@ -1323,14 +1361,17 @@ int v3_chkpt_receive_vm(struct v3_vm_info * vm, char * store, char * url) {
             goto out;
        }
     }        
+
+ memdone:
     
-    if ((ret = v3_load_vm_devices(vm, chkpt)) == -1) {
+    if (!(opts & V3_CHKPT_OPT_SKIP_DEVS)) { 
+      if ((ret = v3_load_vm_devices(vm, chkpt)) == -1) {
        PrintError(vm, VCORE_NONE, "Unable to load devices\n");
        ret = -1;
        goto out;
+      }
     }
     
-    
     if ((ret = load_header(vm, chkpt)) == -1) {
        PrintError(vm, VCORE_NONE, "Unable to load header\n");
        ret = -1;
@@ -1338,13 +1379,15 @@ int v3_chkpt_receive_vm(struct v3_vm_info * vm, char * store, char * url) {
     }
     
     //per core cloning
-    for (i = 0; i < vm->num_cores; i++) {
-       if ((ret = load_core(&(vm->cores[i]), chkpt)) == -1) {
-           PrintError(vm, VCORE_NONE, "Error loading core state (core=%d)\n", i);
-           goto out;
+    if (!(opts & V3_CHKPT_OPT_SKIP_CORES)) {
+      for (i = 0; i < vm->num_cores; i++) {
+       if ((ret = load_core(&(vm->cores[i]), chkpt, opts)) == -1) {
+         PrintError(vm, VCORE_NONE, "Error loading core state (core=%d)\n", i);
+         goto out;
        }
+      }
     }
-    
+
  out:
     if (ret==-1) { 
        PrintError(vm, VCORE_NONE, "Unable to receive VM\n");
@@ -1366,7 +1409,11 @@ int v3_chkpt_receive_vm(struct v3_vm_info * vm, char * store, char * url) {
        v3_lower_barrier(vm);
     } 
     
-    v3_bitmap_deinit(&mod_pgs);
+
+    if (!(opts & V3_CHKPT_OPT_SKIP_MEM)) { 
+      v3_bitmap_deinit(&mod_pgs);
+    }
+
     chkpt_close(chkpt);
 
     return ret;