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 typedef struct VirtQueue VirtQueue;
  50 typedef struct VirtIODevice VirtIODevice;
  51
  52 typedef struct VRingDesc
  53 {
  54     uint64_t addr;
  55     uint32_t len;
  56     uint16_t flags;
  57     uint16_t next;
  58 } VRingDesc;
  59
  60 typedef struct VRingAvail
  61 {
  62     uint16_t flags;
  63     uint16_t idx;
  64     uint16_t ring[0];
  65 } VRingAvail;
  66
  67 typedef struct VRingUsedElem
  68 {
  69     uint32_t id;
  70     uint32_t len;
  71 } VRingUsedElem;
  72
  73 typedef struct VRingUsed
  74 {
  75     uint16_t flags;
  76     uint16_t idx;
  77     VRingUsedElem ring[0];
  78 } VRingUsed;
  79
  80 typedef struct VRing
  81 {
  82     unsigned int num;
  83     VRingDesc *desc;
  84     VRingAvail *avail;
  85     VRingUsed *used;
  86 } VRing;
  87
  88 struct VirtQueue
  89 {
  90     VRing vring;
  91     uint32_t pfn;
  92     uint16_t last_avail_idx;
  93     int inuse;
  94     void (*handle_output)(VirtIODevice *vdev, VirtQueue *vq);
  95 };
  96
  97 #define VIRTQUEUE_MAX_SIZE 1024
  98
  99 typedef struct VirtQueueElement
 100 {
 101     unsigned int index;
 102     unsigned int out_num;
 103     unsigned int in_num;
 104     struct iovec in_sg[VIRTQUEUE_MAX_SIZE];
 105     struct iovec out_sg[VIRTQUEUE_MAX_SIZE];
 106 } VirtQueueElement;
 107
 108 #define VIRTIO_PCI_QUEUE_MAX    16
 109
 110 struct VirtIODevice
 111 {
 112     PCIDevice pci_dev;
 113     const char *name;
 114     uint32_t addr;
 115     uint8_t status;
 116     uint8_t isr;
 117     uint16_t queue_sel;
 118     uint32_t features;
 119     size_t config_len;
 120     void *config;
 121     uint32_t (*get_features)(VirtIODevice *vdev);
 122     void (*set_features)(VirtIODevice *vdev, uint32_t val);
 123     void (*update_config)(VirtIODevice *vdev, uint8_t *config);
 124     void (*reset)(VirtIODevice *vdev);
 125     VirtQueue vq[VIRTIO_PCI_QUEUE_MAX];
 126 };
 127
 128 VirtIODevice *virtio_init_pci(PCIBus *bus, const char *name,
 129                               uint16_t vendor, uint16_t device,
 130                               uint16_t subvendor, uint16_t subdevice,
 131                               uint8_t class_code, uint8_t subclass_code,
 132                               uint8_t pif, size_t config_size,
 133                               size_t struct_size);
 134
 135 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
 136                             void (*handle_output)(VirtIODevice *,
 137                                                   VirtQueue *));
 138
 139 void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
 140                     unsigned int len);
 141
 142 int virtqueue_pop(VirtQueue *vq, VirtQueueElement *elem);
 143
 144 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
 145
 146 void virtio_save(VirtIODevice *vdev, QEMUFile *f);
 147
 148 void virtio_load(VirtIODevice *vdev, QEMUFile *f);
 149
 150 #endif