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.


integrated new configuration system
[palacios.git] / palacios / src / devices / lnx_virtio_blk.c
index 5eefbf8..7bc41a6 100644 (file)
  */
 
 #include <palacios/vmm.h>
-
+#include <palacios/vmm_dev_mgr.h>
 #include <devices/lnx_virtio_pci.h>
-
+#include <palacios/vm_guest_mem.h>
 
 #include <devices/pci.h>
 
 
+
+#ifndef CONFIG_DEBUG_VIRTIO_BLK
+#undef PrintDebug
+#define PrintDebug(fmt, args...)
+#endif
+
+
+#define BLK_CAPACITY_PORT     20
+#define BLK_MAX_SIZE_PORT     28
+#define BLK_MAX_SEG_PORT      32
+#define BLK_CYLINDERS_PORT    36
+#define BLK_HEADS_PORT        38
+#define BLK_SECTS_PORT        39
+
+#define BLK_IN_REQ            0
+#define BLK_OUT_REQ           1
+#define BLK_SCSI_CMD          2
+
+#define BLK_BARRIER_FLAG     0x80000000
+
+#define BLK_STATUS_OK             0
+#define BLK_STATUS_ERR            1
+#define BLK_STATUS_NOT_SUPPORTED  2
+
+
 struct blk_config {
     uint64_t capacity;
     uint32_t max_size;
@@ -36,6 +61,13 @@ struct blk_config {
 
 
 
+struct blk_op_hdr {
+    uint32_t type;
+    uint32_t prior;
+    uint64_t sector;
+} __attribute__((packed));
+
+#define QUEUE_SIZE 128
 
 /* Host Feature flags */
 #define VIRTIO_BARRIER       0x01       /* Does host support barriers? */
@@ -44,87 +76,408 @@ struct blk_config {
 #define VIRTIO_LEGACY_GEOM   0x10       /* Indicates support of legacy geometry */
 
 
+struct virtio_dev_state {
+    struct vm_device * pci_bus;
+    struct list_head dev_list;
+    struct guest_info * vm;
+};
 
 struct virtio_blk_state {
-    struct blk_config block_cfg;
-    struct virtio_config virtio_cfg;
 
-    struct vm_device * pci_bus;
     struct pci_device * pci_dev;
+    struct blk_config block_cfg;
+    struct virtio_config virtio_cfg;
 
-    struct virtio_device * virtio_dev; // the virtio device struction for _this_ device
     
+    struct virtio_queue queue;
+
+    struct v3_dev_blk_ops * ops;
+
+    void * backend_data;
 
     int io_range_size;
+
+    struct virtio_dev_state * virtio_dev;
+
+    struct list_head dev_link;
 };
 
 
+static int virtio_free(struct vm_device * dev) {
+    return -1;
+}
+
+static int blk_reset(struct virtio_blk_state * virtio) {
+
+    virtio->queue.ring_desc_addr = 0;
+    virtio->queue.ring_avail_addr = 0;
+    virtio->queue.ring_used_addr = 0;
+    virtio->queue.pfn = 0;
+    virtio->queue.cur_avail_idx = 0;
+
+    virtio->virtio_cfg.status = 0;
+    virtio->virtio_cfg.pci_isr = 0;
+    return 0;
+}
+
+
+static int virtio_reset(struct vm_device * dev) {
+    struct virtio_dev_state * dev_state = (struct virtio_dev_state *)(dev->private_data);
+    struct virtio_blk_state * blk_state = NULL;
+
+    list_for_each_entry(blk_state, &(dev_state->dev_list), dev_link) {
+       blk_reset(blk_state);
+    }
+
+    return 0;
+}
+
+static int handle_read_op(struct virtio_blk_state * blk_state, uint8_t * buf, uint64_t * sector, uint64_t len) {
+    int ret = -1;
+
+    PrintDebug("Reading Disk\n");
+    ret = blk_state->ops->read(buf, *sector, len, (void *)(blk_state->backend_data));
+    *sector += len;
+
+    return ret;
+}
+
+
+static int handle_write_op(struct virtio_blk_state * blk_state, uint8_t * buf, uint64_t * sector, uint64_t len) {
+    int ret = -1;
+
+    PrintDebug("Writing Disk\n");
+    ret = blk_state->ops->write(buf, *sector, len, (void *)(blk_state->backend_data));
+    *sector += len;
+
+    return ret;
+}
+
+
+
+// multiple block operations need to increment the sector 
+
+static int handle_block_op(struct virtio_blk_state * blk_state, struct blk_op_hdr * hdr, 
+                          struct vring_desc * buf_desc, uint8_t * status) {
+    uint8_t * buf = NULL;
+
+    PrintDebug("Handling Block op\n");
+    if (guest_pa_to_host_va(blk_state->virtio_dev->vm, buf_desc->addr_gpa, (addr_t *)&(buf)) == -1) {
+       PrintError("Could not translate buffer address\n");
+       return -1;
+    }
+
+    PrintDebug("Sector=%p Length=%d\n", (void *)(addr_t)(hdr->sector), buf_desc->length);
+
+    if (hdr->type == BLK_IN_REQ) {
+       if (handle_read_op(blk_state, buf, &(hdr->sector), buf_desc->length) == -1) {
+           *status = BLK_STATUS_ERR;
+           return -1;
+       } else {
+           *status = BLK_STATUS_OK;
+       }
+    } else if (hdr->type == BLK_OUT_REQ) {
+       if (handle_write_op(blk_state, buf, &(hdr->sector), buf_desc->length) == -1) {
+           *status = BLK_STATUS_ERR;
+           return -1;
+       } else {
+           *status = BLK_STATUS_OK;
+       }
+    } else if (hdr->type == BLK_SCSI_CMD) {
+       PrintError("VIRTIO: SCSI Command Not supported!!!\n");
+       *status = BLK_STATUS_NOT_SUPPORTED;
+       return -1;
+    }
+
+    PrintDebug("Returning Status: %d\n", *status);
+
+    return 0;
+}
+
+static int get_desc_count(struct virtio_queue * q, int index) {
+    struct vring_desc * tmp_desc = &(q->desc[index]);
+    int cnt = 1;
+    
+    while (tmp_desc->flags & VIRTIO_NEXT_FLAG) {
+       tmp_desc = &(q->desc[tmp_desc->next]);
+       cnt++;
+    }
+
+    return cnt;
+}
+
 
 
-static int virtio_io_write(uint16_t port, void * src, uint_t length, struct vm_device * dev) {
-    struct virtio_device * virtio_dev = find_virtio_dev(dev);
-    int port_idx = port % virtio->io_range_size;
-    uint8_t * cfg_ptr = (uint8_t *)cfg;
+static int handle_kick(struct virtio_blk_state * blk_state) {  
+    struct virtio_queue * q = &(blk_state->queue);
+
+    PrintDebug("VIRTIO KICK: cur_index=%d (mod=%d), avail_index=%d\n", 
+              q->cur_avail_idx, q->cur_avail_idx % QUEUE_SIZE, q->avail->index);
+
+    while (q->cur_avail_idx < q->avail->index) {
+       struct vring_desc * hdr_desc = NULL;
+       struct vring_desc * buf_desc = NULL;
+       struct vring_desc * status_desc = NULL;
+       struct blk_op_hdr hdr;
+       addr_t hdr_addr = 0;
+       uint16_t desc_idx = q->avail->ring[q->cur_avail_idx % QUEUE_SIZE];
+       int desc_cnt = get_desc_count(q, desc_idx);
+       int i = 0;
+       uint8_t * status_ptr = NULL;
+       uint8_t status = BLK_STATUS_OK;
+       uint32_t req_len = 0;
+
+       PrintDebug("Descriptor Count=%d, index=%d\n", desc_cnt, q->cur_avail_idx % QUEUE_SIZE);
+
+       if (desc_cnt < 3) {
+           PrintError("Block operations must include at least 3 descriptors\n");
+           return -1;
+       }
+
+       hdr_desc = &(q->desc[desc_idx]);
+
+
+       PrintDebug("Header Descriptor (ptr=%p) gpa=%p, len=%d, flags=%x, next=%d\n", hdr_desc, 
+                  (void *)(hdr_desc->addr_gpa), hdr_desc->length, hdr_desc->flags, hdr_desc->next);    
+
+       if (guest_pa_to_host_va(blk_state->virtio_dev->vm, hdr_desc->addr_gpa, &(hdr_addr)) == -1) {
+           PrintError("Could not translate block header address\n");
+           return -1;
+       }
+
+       // We copy the block op header out because we are going to modify its contents
+       memcpy(&hdr, (void *)hdr_addr, sizeof(struct blk_op_hdr));
+       
+       PrintDebug("Blk Op Hdr (ptr=%p) type=%d, sector=%p\n", (void *)hdr_addr, hdr.type, (void *)hdr.sector);
+
+       desc_idx = hdr_desc->next;
+
+       for (i = 0; i < desc_cnt - 2; i++) {
+           uint8_t tmp_status = BLK_STATUS_OK;
+
+           buf_desc = &(q->desc[desc_idx]);
+
+           PrintDebug("Buffer Descriptor (ptr=%p) gpa=%p, len=%d, flags=%x, next=%d\n", buf_desc, 
+                      (void *)(buf_desc->addr_gpa), buf_desc->length, buf_desc->flags, buf_desc->next);
+
+           if (handle_block_op(blk_state, &hdr, buf_desc, &tmp_status) == -1) {
+               PrintError("Error handling block operation\n");
+               return -1;
+           }
+
+           if (tmp_status != BLK_STATUS_OK) {
+               status = tmp_status;
+           }
+
+           req_len += buf_desc->length;
+           desc_idx = buf_desc->next;
+       }
+
+       status_desc = &(q->desc[desc_idx]);
+
+       PrintDebug("Status Descriptor (ptr=%p) gpa=%p, len=%d, flags=%x, next=%d\n", status_desc, 
+                  (void *)(status_desc->addr_gpa), status_desc->length, status_desc->flags, status_desc->next);
+
+       if (guest_pa_to_host_va(blk_state->virtio_dev->vm, status_desc->addr_gpa, (addr_t *)&(status_ptr)) == -1) {
+           PrintError("Could not translate status address\n");
+           return -1;
+       }
+
+       req_len += status_desc->length;
+       *status_ptr = status;
+
+       q->used->ring[q->used->index % QUEUE_SIZE].id = q->avail->ring[q->cur_avail_idx % QUEUE_SIZE];
+       q->used->ring[q->used->index % QUEUE_SIZE].length = req_len; // What do we set this to????
+
+       q->used->index++;
+       q->cur_avail_idx++;
+    }
+
+    if (!(q->avail->flags & VIRTIO_NO_IRQ_FLAG)) {
+       PrintDebug("Raising IRQ %d\n",  blk_state->pci_dev->config_header.intr_line);
+       v3_pci_raise_irq(blk_state->virtio_dev->pci_bus, 0, blk_state->pci_dev);
+       blk_state->virtio_cfg.pci_isr = 1;
+    }
+
+    return 0;
+}
+
+static int virtio_io_write(uint16_t port, void * src, uint_t length, void * private_data) {
+    struct virtio_blk_state * blk_state = (struct virtio_blk_state *)private_data;
+    int port_idx = port % blk_state->io_range_size;
+
 
     PrintDebug("VIRTIO BLOCK Write for port %d (index=%d) len=%d, value=%x\n", 
               port, port_idx,  length, *(uint32_t *)src);
 
 
 
-    switch (port_index) {
+    switch (port_idx) {
+       case GUEST_FEATURES_PORT:
+           if (length != 4) {
+               PrintError("Illegal write length for guest features\n");
+               return -1;
+           }
+           
+           blk_state->virtio_cfg.guest_features = *(uint32_t *)src;
+           PrintDebug("Setting Guest Features to %x\n", blk_state->virtio_cfg.guest_features);
+
+           break;
+       case VRING_PG_NUM_PORT:
+           if (length == 4) {
+               addr_t pfn = *(uint32_t *)src;
+               addr_t page_addr = (pfn << VIRTIO_PAGE_SHIFT);
+
+
+               blk_state->queue.pfn = pfn;
+               
+               blk_state->queue.ring_desc_addr = page_addr ;
+               blk_state->queue.ring_avail_addr = page_addr + (QUEUE_SIZE * sizeof(struct vring_desc));
+               blk_state->queue.ring_used_addr = ( blk_state->queue.ring_avail_addr + \
+                                                sizeof(struct vring_avail)    + \
+                                                (QUEUE_SIZE * sizeof(uint16_t)));
+               
+               // round up to next page boundary.
+               blk_state->queue.ring_used_addr = (blk_state->queue.ring_used_addr + 0xfff) & ~0xfff;
+
+               if (guest_pa_to_host_va(blk_state->virtio_dev->vm, blk_state->queue.ring_desc_addr, (addr_t *)&(blk_state->queue.desc)) == -1) {
+                   PrintError("Could not translate ring descriptor address\n");
+                   return -1;
+               }
+
+
+               if (guest_pa_to_host_va(blk_state->virtio_dev->vm, blk_state->queue.ring_avail_addr, (addr_t *)&(blk_state->queue.avail)) == -1) {
+                   PrintError("Could not translate ring available address\n");
+                   return -1;
+               }
+
+
+               if (guest_pa_to_host_va(blk_state->virtio_dev->vm, blk_state->queue.ring_used_addr, (addr_t *)&(blk_state->queue.used)) == -1) {
+                   PrintError("Could not translate ring used address\n");
+                   return -1;
+               }
+
+               PrintDebug("RingDesc_addr=%p, Avail_addr=%p, Used_addr=%p\n",
+                          (void *)(blk_state->queue.ring_desc_addr),
+                          (void *)(blk_state->queue.ring_avail_addr),
+                          (void *)(blk_state->queue.ring_used_addr));
+
+               PrintDebug("RingDesc=%p, Avail=%p, Used=%p\n", 
+                          blk_state->queue.desc, blk_state->queue.avail, blk_state->queue.used);
+
+           } else {
+               PrintError("Illegal write length for page frame number\n");
+               return -1;
+           }
+           break;
+       case VRING_Q_SEL_PORT:
+           blk_state->virtio_cfg.vring_queue_selector = *(uint16_t *)src;
+
+           if (blk_state->virtio_cfg.vring_queue_selector != 0) {
+               PrintError("Virtio Block device only uses 1 queue, selected %d\n", 
+                          blk_state->virtio_cfg.vring_queue_selector);
+               return -1;
+           }
+
+           break;
        case VRING_Q_NOTIFY_PORT:
-           // handle output
-           PrintError("Notification\n");
-           return -1;
+           PrintDebug("Handling Kick\n");
+           if (handle_kick(blk_state) == -1) {
+               PrintError("Could not handle Block Notification\n");
+               return -1;
+           }
            break;
-       case VRING_STATUS_PORT:
-           if (cfg->status == 0) {
+       case VIRTIO_STATUS_PORT:
+           blk_state->virtio_cfg.status = *(uint8_t *)src;
+
+           if (blk_state->virtio_cfg.status == 0) {
                PrintDebug("Resetting device\n");
-               return -1;
-               //reset
+               blk_reset(blk_state);
            }
+
+           break;
+
+       case VIRTIO_ISR_PORT:
+           blk_state->virtio_cfg.pci_isr = *(uint8_t *)src;
            break;
        default:
            return -1;
            break;
     }
 
-
-
-
     return length;
 }
 
 
-static int virtio_io_read(uint16_t port, void * dst, uint_t length, struct vm_device * dev) {
-    struct blk_state * virtio = (struct blk_state *)dev->private_data;
-    int port_idx = port % virtio->io_range_size;
-    uint8_t * cfg_ptr = (uint8_t *)cfg;
+static int virtio_io_read(uint16_t port, void * dst, uint_t length, void * private_data) {
+    struct virtio_blk_state * blk_state = (struct virtio_blk_state *)private_data;
+    int port_idx = port % blk_state->io_range_size;
+
 
     PrintDebug("VIRTIO BLOCK Read  for port %d (index =%d), length=%d\n", 
               port, port_idx, length);
 
     switch (port_idx) {
-       // search for device....
-       // call and return dev config read
-       default:
-       return -1;
-    }
+       case HOST_FEATURES_PORT:
+           if (length != 4) {
+               PrintError("Illegal read length for host features\n");
+               return -1;
+           }
 
+           *(uint32_t *)dst = blk_state->virtio_cfg.host_features;
+       
+           break;
+       case VRING_PG_NUM_PORT:
+           if (length != 4) {
+               PrintError("Illegal read length for page frame number\n");
+               return -1;
+           }
 
-    return length;
-}
+           *(uint32_t *)dst = blk_state->queue.pfn;
 
-struct v3_dev_ops  = {
-    .free = virtio_free,
-    .reset = NULL,
-    .stop = NULL,
-    .start = NULL
-};
+           break;
+       case VRING_SIZE_PORT:
+           if (length != 2) {
+               PrintError("Illegal read length for vring size\n");
+               return -1;
+           }
+               
+           *(uint16_t *)dst = blk_state->queue.queue_size;
 
+           break;
 
-static int virtio_free(struct vm_device * dev) {
-    return -1;
+       case VIRTIO_STATUS_PORT:
+           if (length != 1) {
+               PrintError("Illegal read length for status\n");
+               return -1;
+           }
+
+           *(uint8_t *)dst = blk_state->virtio_cfg.status;
+           break;
+
+       case VIRTIO_ISR_PORT:
+           *(uint8_t *)dst = blk_state->virtio_cfg.pci_isr;
+           blk_state->virtio_cfg.pci_isr = 0;
+           v3_pci_lower_irq(blk_state->virtio_dev->pci_bus, 0, blk_state->pci_dev);
+           break;
+
+       default:
+           if ( (port_idx >= sizeof(struct virtio_config)) && 
+                (port_idx < (sizeof(struct virtio_config) + sizeof(struct blk_config))) ) {
+               int cfg_offset = port_idx - sizeof(struct virtio_config);
+               uint8_t * cfg_ptr = (uint8_t *)&(blk_state->block_cfg);
+
+               memcpy(dst, cfg_ptr + cfg_offset, length);
+               
+           } else {
+               PrintError("Read of Unhandled Virtio Read\n");
+               return -1;
+           }
+         
+           break;
+    }
+
+    return length;
 }
 
 
@@ -132,7 +485,7 @@ static int virtio_free(struct vm_device * dev) {
 
 static struct v3_device_ops dev_ops = {
     .free = virtio_free,
-    .reset = NULL,
+    .reset = virtio_reset,
     .start = NULL,
     .stop = NULL,
 };
@@ -141,98 +494,145 @@ static struct v3_device_ops dev_ops = {
 
 
 
-
-static int virtio_init(struct guest_info * vm, void * cfg_data) {
-    struct vm_device * pci_bus = v3_find_dev(vm, (char *)cfg_data);
-    struct virtio_blk_state * virtio_state = NULL;
+static int register_dev(struct virtio_dev_state * virtio, struct virtio_blk_state * blk_state) {
+    // initialize PCI
     struct pci_device * pci_dev = NULL;
+    struct v3_pci_bar bars[6];
+    int num_ports = sizeof(struct virtio_config) + sizeof(struct blk_config);
+    int tmp_ports = num_ports;
+    int i;
 
-    PrintDebug("Initializing VIRTIO Block device\n");
 
-    if (pci_bus == NULL) {
-       PrintError("VirtIO devices require a PCI Bus");
+
+    // This gets the number of ports, rounded up to a power of 2
+    blk_state->io_range_size = 1; // must be a power of 2
+    
+    while (tmp_ports > 0) {
+       tmp_ports >>= 1;
+       blk_state->io_range_size <<= 1;
+    }
+       
+    // this is to account for any low order bits being set in num_ports
+    // if there are none, then num_ports was already a power of 2 so we shift right to reset it
+    if ((num_ports & ((blk_state->io_range_size >> 1) - 1)) == 0) {
+       blk_state->io_range_size >>= 1;
+    }
+    
+    
+    for (i = 0; i < 6; i++) {
+       bars[i].type = PCI_BAR_NONE;
+    }
+    
+    PrintDebug("Virtio-BLK io_range_size = %d\n", blk_state->io_range_size);
+    
+    bars[0].type = PCI_BAR_IO;
+    bars[0].default_base_port = -1;
+    bars[0].num_ports = blk_state->io_range_size;
+    
+    bars[0].io_read = virtio_io_read;
+    bars[0].io_write = virtio_io_write;
+    bars[0].private_data = blk_state;
+    
+    pci_dev = v3_pci_register_device(virtio->pci_bus, PCI_STD_DEVICE, 
+                                    0, PCI_AUTO_DEV_NUM, 0,
+                                    "LNX_VIRTIO_BLK", bars,
+                                    NULL, NULL, NULL, blk_state);
+    
+    if (!pci_dev) {
+       PrintError("Could not register PCI Device\n");
        return -1;
     }
-
     
-    virtio_state  = (struct virtio_blk_state *)V3_Malloc(sizeof(struct virtio_blk_state));
-    memset(virtio_state, 0, sizeof(struct virtio_blk_state));
+    pci_dev->config_header.vendor_id = VIRTIO_VENDOR_ID;
+    pci_dev->config_header.subsystem_vendor_id = VIRTIO_SUBVENDOR_ID;
+    
+    
+    pci_dev->config_header.device_id = VIRTIO_BLOCK_DEV_ID;
+    pci_dev->config_header.class = PCI_CLASS_STORAGE;
+    pci_dev->config_header.subclass = PCI_STORAGE_SUBCLASS_OTHER;
+    
+    pci_dev->config_header.subsystem_id = VIRTIO_BLOCK_SUBDEVICE_ID;
+    
+    
+    pci_dev->config_header.intr_pin = 1;
+    
+    pci_dev->config_header.max_latency = 1; // ?? (qemu does it...)
+    
+    
+    blk_state->pci_dev = pci_dev;
+    
+    /* Block configuration */
+    blk_state->virtio_cfg.host_features = VIRTIO_SEG_MAX;
+    blk_state->block_cfg.max_seg = QUEUE_SIZE - 2;
 
+    // Virtio Block only uses one queue
+    blk_state->queue.queue_size = QUEUE_SIZE;
 
-    struct vm_device * dev = v3_allocate_device("LNX_VIRTIO_BLK", &dev_ops, virtio_state);
-    if (v3_attach_device(vm, dev) == -1) {
-       PrintError("Could not attach device %s\n", "LNX_VIRTIO_BLK");
-       return -1;
-    }
+    blk_state->virtio_dev = virtio;
 
+    blk_reset(blk_state);
 
-    // PCI initialization
-    {
-       struct v3_pci_bar bars[6];
-       int num_ports = sizeof(struct virtio_config) + sizeof(struct blk_config);
-       int tmp_ports = num_ports;
-       int i;
 
+    return 0;
+}
 
 
-       // This gets the number of ports, rounded up to a power of 2
-       virtio_state->io_range_size = 1; // must be a power of 2
+static int connect_fn(struct guest_info * info, 
+                     void * frontend_data, 
+                     struct v3_dev_blk_ops * ops, 
+                     v3_cfg_tree_t * cfg, 
+                     void * private_data) {
 
-       while (tmp_ports > 0) {
-           tmp_ports >>= 1;
-           virtio_state->io_range_size <<= 1;
-       }
-       
-       // this is to account for any low order bits being set in num_ports
-       // if there are none, then num_ports was already a power of 2 so we shift right to reset it
-       if ((num_ports & ((virtio_state->io_range_size >> 1) - 1)) == 0) {
-           virtio_state->io_range_size >>= 1;
-       }
+    struct virtio_dev_state * virtio = (struct virtio_dev_state *)frontend_data;
 
+    struct virtio_blk_state * blk_state  = (struct virtio_blk_state *)V3_Malloc(sizeof(struct virtio_blk_state));
+    memset(blk_state, 0, sizeof(struct virtio_blk_state));
 
-       for (i = 0; i < 6; i++) {
-           bars[i].type = PCI_BAR_NONE;
-       }
+    register_dev(virtio, blk_state);
 
-       bars[0].type = PCI_BAR_IO;
-       bars[0].default_base_port = -1;
-       bars[0].num_ports = virtio_state->io_range_size;
+    blk_state->ops = ops;
+    blk_state->backend_data = private_data;
 
-       bars[0].io_read = virtio_io_read;
-       bars[0].io_write = virtio_io_write;
+    blk_state->block_cfg.capacity = ops->get_capacity(private_data);
 
-       pci_dev = v3_pci_register_device(pci_bus, PCI_STD_DEVICE, 
-                                        0, PCI_AUTO_DEV_NUM, 0,
-                                        "LNX_VIRTIO_BLK", bars,
-                                        NULL, NULL, NULL, dev);
+    PrintDebug("Virtio Capacity = %d -- 0x%p\n", (int)(virtio->block_cfg.capacity), 
+              (void *)(addr_t)(virtio->block_cfg.capacity));
 
-       if (!pci_dev) {
-           PrintError("Could not register PCI Device\n");
-           return -1;
-       }
-       
-       pci_dev->config_header.vendor_id = VIRTIO_VENDOR_ID;
-       pci_dev->config_header.subsystem_vendor_id = VIRTIO_SUBVENDOR_ID;
-       
+    return 0;
+}
 
-       pci_dev->config_header.device_id = VIRTIO_BLOCK_DEV_ID;
-       pci_dev->config_header.class = PCI_CLASS_STORAGE;
-       pci_dev->config_header.subclass = PCI_STORAGE_SUBCLASS_OTHER;
-    
-       pci_dev->config_header.subsystem_id = VIRTIO_BLOCK_SUBDEVICE_ID;
 
+static int virtio_init(struct guest_info * vm, v3_cfg_tree_t * cfg) {
+    struct vm_device * pci_bus = v3_find_dev(vm, v3_cfg_val(cfg, "bus"));
+    struct virtio_dev_state * virtio_state = NULL;
+    char * name = v3_cfg_val(cfg, "name");
+
+    PrintDebug("Initializing VIRTIO Block device\n");
+
+    if (pci_bus == NULL) {
+       PrintError("VirtIO devices require a PCI Bus");
+       return -1;
+    }
 
-       pci_dev->config_header.intr_pin = 1;
 
-       pci_dev->config_header.max_latency = 1; // ?? (qemu does it...)
+    virtio_state  = (struct virtio_dev_state *)V3_Malloc(sizeof(struct virtio_dev_state));
+    memset(virtio_state, 0, sizeof(struct virtio_dev_state));
 
+    INIT_LIST_HEAD(&(virtio_state->dev_list));
+    virtio_state->pci_bus = pci_bus;
+    virtio_state->vm = vm;
 
-       virtio_state->pci_dev = pci_dev;
-       virtio_state->pci_bus = pci_bus;
+    struct vm_device * dev = v3_allocate_device(name, &dev_ops, virtio_state);
+    if (v3_attach_device(vm, dev) == -1) {
+       PrintError("Could not attach device %s\n", name);
+       return -1;
+    }
 
-       /* Block configuration */
+    if (v3_dev_add_blk_frontend(vm, name, connect_fn, (void *)virtio_state) == -1) {
+       PrintError("Could not register %s as block frontend\n", name);
+       return -1;
     }
-    
+
     return 0;
 }