hw/virtio.h

   1 /*
   2  * Virtio Support
   3  *
   4  * Copyright IBM, Corp. 2007
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #ifndef _QEMU_VIRTIO_H
  15 #define _QEMU_VIRTIO_H
  16
  17 #include "hw.h"
  18 #include "pci.h"
  19
  20 /* from Linux's linux/virtio_config.h */
  21
  22 /* Status byte for guest to report progress, and synchronize features. */
  23 /* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
  24 #define VIRTIO_CONFIG_S_ACKNOWLEDGE     1
  25 /* We have found a driver for the device. */
  26 #define VIRTIO_CONFIG_S_DRIVER          2
  27 /* Driver has used its parts of the config, and is happy */
  28 #define VIRTIO_CONFIG_S_DRIVER_OK       4
  29 /* We've given up on this device. */
  30 #define VIRTIO_CONFIG_S_FAILED          0x80
  31
  32 /* We notify when the ring is completely used, even if the guest is supressing
  33  * callbacks */
  34 #define VIRTIO_F_NOTIFY_ON_EMPTY        24
  35
  36 /* from Linux's linux/virtio_ring.h */
  37
  38 /* This marks a buffer as continuing via the next field. */
  39 #define VRING_DESC_F_NEXT       1
  40 /* This marks a buffer as write-only (otherwise read-only). */
  41 #define VRING_DESC_F_WRITE      2
  42
  43 /* This means don't notify other side when buffer added. */
  44 #define VRING_USED_F_NO_NOTIFY  1
  45 /* This means don't interrupt guest when buffer consumed. */
  46 #define VRING_AVAIL_F_NO_INTERRUPT      1
  47
  48 struct VirtQueue;
  49
  50 static inline target_phys_addr_t vring_align(target_phys_addr_t addr,
  51                                              unsigned long align)
  52 {
  53     return (addr + align - 1) & ~(align - 1);
  54 }
  55
  56 typedef struct VirtQueue VirtQueue;
  57 typedef struct VirtIODevice VirtIODevice;
  58
  59 #define VIRTQUEUE_MAX_SIZE 1024
  60
  61 typedef struct VirtQueueElement
  62 {
  63     unsigned int index;
  64     unsigned int out_num;
  65     unsigned int in_num;
  66     target_phys_addr_t in_addr[VIRTQUEUE_MAX_SIZE];
  67     struct iovec in_sg[VIRTQUEUE_MAX_SIZE];
  68     struct iovec out_sg[VIRTQUEUE_MAX_SIZE];
  69 } VirtQueueElement;
  70
  71 #define VIRTIO_PCI_QUEUE_MAX 16
  72
  73 struct VirtIODevice
  74 {
  75     PCIDevice pci_dev;
  76     const char *name;
  77     uint32_t addr;
  78     uint8_t status;
  79     uint8_t isr;
  80     uint16_t queue_sel;
  81     uint32_t features;
  82     size_t config_len;
  83     void *config;
  84     uint32_t (*get_features)(VirtIODevice *vdev);
  85     void (*set_features)(VirtIODevice *vdev, uint32_t val);
  86     void (*get_config)(VirtIODevice *vdev, uint8_t *config);
  87     void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
  88     void (*reset)(VirtIODevice *vdev);
  89     VirtQueue *vq;
  90 };
  91
  92 VirtIODevice *virtio_init_pci(PCIBus *bus, const char *name,
  93                               uint16_t vendor, uint16_t device,
  94                               uint16_t subvendor, uint16_t subdevice,
  95                               uint8_t class_code, uint8_t subclass_code,
  96                               uint8_t pif, size_t config_size,
  97                               size_t struct_size);
  98
  99 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
 100                             void (*handle_output)(VirtIODevice *,
 101                                                   VirtQueue *));
 102
 103 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
 104                     unsigned int len);
 105 void virtqueue_flush(VirtQueue *vq, unsigned int count);
 106 void virtqueue_fill(VirtQueue *vq, const VirtQueueElement *elem,
 107                     unsigned int len, unsigned int idx);
 108
 109 int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem);
 110 int virtqueue_avail_bytes(VirtQueue *vq, int in_bytes, int out_bytes);
 111
 112 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
 113
 114 void virtio_save(VirtIODevice *vdev, QEMUFile *f);
 115
 116 void virtio_load(VirtIODevice *vdev, QEMUFile *f);
 117
 118 void virtio_notify_config(VirtIODevice *vdev);
 119
 120 void virtio_queue_set_notification(VirtQueue *vq, int enable);
 121
 122 int virtio_queue_ready(VirtQueue *vq);
 123
 124 int virtio_queue_empty(VirtQueue *vq);
 125
 126 #endif