LXR qemu/pc-bios/s390-ccw/virtio.h

   1/*
   2 * Virtio driver bits
   3 *
   4 * Copyright (c) 2013 Alexander Graf <agraf@suse.de>
   5 *
   6 * This work is licensed under the terms of the GNU GPL, version 2 or (at
   7 * your option) any later version. See the COPYING file in the top-level
   8 * directory.
   9 */
  10
  11#ifndef VIRTIO_H
  12#define VIRTIO_H
  13
  14/* Status byte for guest to report progress, and synchronize features. */
  15/* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
  16#define VIRTIO_CONFIG_S_ACKNOWLEDGE     1
  17/* We have found a driver for the device. */
  18#define VIRTIO_CONFIG_S_DRIVER          2
  19/* Driver has used its parts of the config, and is happy */
  20#define VIRTIO_CONFIG_S_DRIVER_OK       4
  21/* We've given up on this device. */
  22#define VIRTIO_CONFIG_S_FAILED          0x80
  23
  24enum VirtioDevType {
  25    VIRTIO_ID_NET = 1,
  26    VIRTIO_ID_BLOCK = 2,
  27    VIRTIO_ID_CONSOLE = 3,
  28    VIRTIO_ID_BALLOON = 5,
  29    VIRTIO_ID_SCSI = 8,
  30};
  31typedef enum VirtioDevType VirtioDevType;
  32
  33struct VqInfo {
  34    uint64_t queue;
  35    uint32_t align;
  36    uint16_t index;
  37    uint16_t num;
  38} __attribute__((packed));
  39typedef struct VqInfo VqInfo;
  40
  41struct VqConfig {
  42    uint16_t index;
  43    uint16_t num;
  44} __attribute__((packed));
  45typedef struct VqConfig VqConfig;
  46
  47#define VIRTIO_RING_SIZE            (PAGE_SIZE * 8)
  48#define VIRTIO_MAX_VQS              3
  49#define KVM_S390_VIRTIO_RING_ALIGN  4096
  50
  51#define VRING_USED_F_NO_NOTIFY  1
  52
  53/* This marks a buffer as continuing via the next field. */
  54#define VRING_DESC_F_NEXT       1
  55/* This marks a buffer as write-only (otherwise read-only). */
  56#define VRING_DESC_F_WRITE      2
  57/* This means the buffer contains a list of buffer descriptors. */
  58#define VRING_DESC_F_INDIRECT   4
  59
  60/* Internal flag to mark follow-up segments as such */
  61#define VRING_HIDDEN_IS_CHAIN   256
  62
  63/* Virtio ring descriptors: 16 bytes.  These can chain together via "next". */
  64struct VRingDesc {
  65    /* Address (guest-physical). */
  66    uint64_t addr;
  67    /* Length. */
  68    uint32_t len;
  69    /* The flags as indicated above. */
  70    uint16_t flags;
  71    /* We chain unused descriptors via this, too */
  72    uint16_t next;
  73} __attribute__((packed));
  74typedef struct VRingDesc VRingDesc;
  75
  76struct VRingAvail {
  77    uint16_t flags;
  78    uint16_t idx;
  79    uint16_t ring[];
  80} __attribute__((packed));
  81typedef struct VRingAvail VRingAvail;
  82
  83/* uint32_t is used here for ids for padding reasons. */
  84struct VRingUsedElem {
  85    /* Index of start of used descriptor chain. */
  86    uint32_t id;
  87    /* Total length of the descriptor chain which was used (written to) */
  88    uint32_t len;
  89} __attribute__((packed));
  90typedef struct VRingUsedElem VRingUsedElem;
  91
  92struct VRingUsed {
  93    uint16_t flags;
  94    uint16_t idx;
  95    VRingUsedElem ring[];
  96} __attribute__((packed));
  97typedef struct VRingUsed VRingUsed;
  98
  99struct VRing {
 100    unsigned int num;
 101    int next_idx;
 102    int used_idx;
 103    VRingDesc *desc;
 104    VRingAvail *avail;
 105    VRingUsed *used;
 106    SubChannelId schid;
 107    long cookie;
 108    int id;
 109};
 110typedef struct VRing VRing;
 111
 112
 113/***********************************************
 114 *               Virtio block                  *
 115 ***********************************************/
 116
 117/*
 118 * Command types
 119 *
 120 * Usage is a bit tricky as some bits are used as flags and some are not.
 121 *
 122 * Rules:
 123 *   VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or
 124 *   VIRTIO_BLK_T_BARRIER.  VIRTIO_BLK_T_FLUSH is a command of its own
 125 *   and may not be combined with any of the other flags.
 126 */
 127
 128/* These two define direction. */
 129#define VIRTIO_BLK_T_IN         0
 130#define VIRTIO_BLK_T_OUT        1
 131
 132/* This bit says it's a scsi command, not an actual read or write. */
 133#define VIRTIO_BLK_T_SCSI_CMD   2
 134
 135/* Cache flush command */
 136#define VIRTIO_BLK_T_FLUSH      4
 137
 138/* Barrier before this op. */
 139#define VIRTIO_BLK_T_BARRIER    0x80000000
 140
 141/* This is the first element of the read scatter-gather list. */
 142struct VirtioBlkOuthdr {
 143        /* VIRTIO_BLK_T* */
 144        uint32_t type;
 145        /* io priority. */
 146        uint32_t ioprio;
 147        /* Sector (ie. 512 byte offset) */
 148        uint64_t sector;
 149};
 150typedef struct VirtioBlkOuthdr VirtioBlkOuthdr;
 151
 152struct VirtioBlkConfig {
 153    uint64_t capacity; /* in 512-byte sectors */
 154    uint32_t size_max; /* max segment size (if VIRTIO_BLK_F_SIZE_MAX) */
 155    uint32_t seg_max;  /* max number of segments (if VIRTIO_BLK_F_SEG_MAX) */
 156
 157    struct VirtioBlkGeometry {
 158        uint16_t cylinders;
 159        uint8_t heads;
 160        uint8_t sectors;
 161    } geometry; /* (if VIRTIO_BLK_F_GEOMETRY) */
 162
 163    uint32_t blk_size; /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
 164
 165    /* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY  */
 166    uint8_t physical_block_exp; /* exponent for physical blk per logical blk */
 167    uint8_t alignment_offset;   /* alignment offset in logical blocks */
 168    uint16_t min_io_size;       /* min I/O size without performance penalty
 169                              in logical blocks */
 170    uint32_t opt_io_size;       /* optimal sustained I/O size in logical blks */
 171
 172    uint8_t wce; /* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */
 173} __attribute__((packed));
 174typedef struct VirtioBlkConfig VirtioBlkConfig;
 175
 176enum guessed_disk_nature_type {
 177    VIRTIO_GDN_NONE     = 0,
 178    VIRTIO_GDN_DASD     = 1,
 179    VIRTIO_GDN_CDROM    = 2,
 180    VIRTIO_GDN_SCSI     = 3,
 181};
 182typedef enum guessed_disk_nature_type VirtioGDN;
 183
 184VirtioGDN virtio_guessed_disk_nature(void);
 185void virtio_assume_eckd(void);
 186void virtio_assume_iso9660(void);
 187
 188bool virtio_ipl_disk_is_valid(void);
 189int virtio_get_block_size(void);
 190uint8_t virtio_get_heads(void);
 191uint8_t virtio_get_sectors(void);
 192uint64_t virtio_get_blocks(void);
 193int virtio_read_many(unsigned long sector, void *load_addr, int sec_num);
 194
 195#define VIRTIO_SECTOR_SIZE 512
 196#define VIRTIO_ISO_BLOCK_SIZE 2048
 197#define VIRTIO_SCSI_BLOCK_SIZE 512
 198#define VIRTIO_DASD_DEFAULT_BLOCK_SIZE 4096
 199
 200static inline unsigned long virtio_sector_adjust(unsigned long sector)
 201{
 202    return sector * (virtio_get_block_size() / VIRTIO_SECTOR_SIZE);
 203}
 204
 205struct VirtioScsiConfig {
 206    uint32_t num_queues;
 207    uint32_t seg_max;
 208    uint32_t max_sectors;
 209    uint32_t cmd_per_lun;
 210    uint32_t event_info_size;
 211    uint32_t sense_size;
 212    uint32_t cdb_size;
 213    uint16_t max_channel;
 214    uint16_t max_target;
 215    uint32_t max_lun;
 216} __attribute__((packed));
 217typedef struct VirtioScsiConfig VirtioScsiConfig;
 218
 219struct ScsiDevice {
 220    uint16_t channel;   /* Always 0 in QEMU     */
 221    uint16_t target;    /* will be scanned over */
 222    uint32_t lun;       /* will be reported     */
 223};
 224typedef struct ScsiDevice ScsiDevice;
 225
 226struct VirtioNetConfig {
 227    uint8_t mac[6];
 228    /* uint16_t status; */               /* Only with VIRTIO_NET_F_STATUS */
 229    /* uint16_t max_virtqueue_pairs; */  /* Only with VIRTIO_NET_F_MQ */
 230};
 231typedef struct VirtioNetConfig VirtioNetConfig;
 232
 233struct VDev {
 234    int nr_vqs;
 235    VRing *vrings;
 236    int cmd_vr_idx;
 237    void *ring_area;
 238    long wait_reply_timeout;
 239    VirtioGDN guessed_disk_nature;
 240    SubChannelId schid;
 241    SenseId senseid;
 242    union {
 243        VirtioBlkConfig blk;
 244        VirtioScsiConfig scsi;
 245        VirtioNetConfig net;
 246    } config;
 247    ScsiDevice *scsi_device;
 248    bool is_cdrom;
 249    int scsi_block_size;
 250    int blk_factor;
 251    uint64_t scsi_last_block;
 252    uint32_t scsi_dev_cyls;
 253    uint8_t scsi_dev_heads;
 254    bool scsi_device_selected;
 255    ScsiDevice selected_scsi_device;
 256    uint64_t netboot_start_addr;
 257    uint32_t max_transfer;
 258    uint32_t guest_features[2];
 259};
 260typedef struct VDev VDev;
 261
 262VDev *virtio_get_device(void);
 263VirtioDevType virtio_get_device_type(void);
 264
 265struct VirtioCmd {
 266    void *data;
 267    int size;
 268    int flags;
 269};
 270typedef struct VirtioCmd VirtioCmd;
 271
 272bool vring_notify(VRing *vr);
 273int drain_irqs(SubChannelId schid);
 274void vring_send_buf(VRing *vr, void *p, int len, int flags);
 275int vr_poll(VRing *vr);
 276int vring_wait_reply(void);
 277int virtio_run(VDev *vdev, int vqid, VirtioCmd *cmd);
 278void virtio_setup_ccw(VDev *vdev);
 279
 280int virtio_net_init(void *mac_addr);
 281
 282#endif /* VIRTIO_H */
 283