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