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 #include "s390-ccw.h"
  15
  16 /* Status byte for guest to report progress, and synchronize features. */
  17 /* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
  18 #define VIRTIO_CONFIG_S_ACKNOWLEDGE     1
  19 /* We have found a driver for the device. */
  20 #define VIRTIO_CONFIG_S_DRIVER          2
  21 /* Driver has used its parts of the config, and is happy */
  22 #define VIRTIO_CONFIG_S_DRIVER_OK       4
  23 /* We've given up on this device. */
  24 #define VIRTIO_CONFIG_S_FAILED          0x80
  25
  26 enum VirtioDevType {
  27     VIRTIO_ID_NET = 1,
  28     VIRTIO_ID_BLOCK = 2,
  29     VIRTIO_ID_CONSOLE = 3,
  30     VIRTIO_ID_BALLOON = 5,
  31     VIRTIO_ID_SCSI = 8,
  32 };
  33 typedef enum VirtioDevType VirtioDevType;
  34
  35 struct VirtioDevHeader {
  36     VirtioDevType type:8;
  37     uint8_t num_vq;
  38     uint8_t feature_len;
  39     uint8_t config_len;
  40     uint8_t status;
  41     uint8_t vqconfig[];
  42 } __attribute__((packed));
  43 typedef struct VirtioDevHeader VirtioDevHeader;
  44
  45 struct VirtioVqConfig {
  46     uint64_t token;
  47     uint64_t address;
  48     uint16_t num;
  49     uint8_t pad[6];
  50 } __attribute__((packed));
  51 typedef struct VirtioVqConfig VirtioVqConfig;
  52
  53 struct VqInfo {
  54     uint64_t queue;
  55     uint32_t align;
  56     uint16_t index;
  57     uint16_t num;
  58 } __attribute__((packed));
  59 typedef struct VqInfo VqInfo;
  60
  61 struct VqConfig {
  62     uint16_t index;
  63     uint16_t num;
  64 } __attribute__((packed));
  65 typedef struct VqConfig VqConfig;
  66
  67 struct VirtioDev {
  68     VirtioDevHeader *header;
  69     VirtioVqConfig *vqconfig;
  70     char *host_features;
  71     char *guest_features;
  72     char *config;
  73 };
  74 typedef struct VirtioDev VirtioDev;
  75
  76 #define VIRTIO_RING_SIZE            (PAGE_SIZE * 8)
  77 #define VIRTIO_MAX_VQS              3
  78 #define KVM_S390_VIRTIO_RING_ALIGN  4096
  79
  80 #define VRING_USED_F_NO_NOTIFY  1
  81
  82 /* This marks a buffer as continuing via the next field. */
  83 #define VRING_DESC_F_NEXT       1
  84 /* This marks a buffer as write-only (otherwise read-only). */
  85 #define VRING_DESC_F_WRITE      2
  86 /* This means the buffer contains a list of buffer descriptors. */
  87 #define VRING_DESC_F_INDIRECT   4
  88
  89 /* Internal flag to mark follow-up segments as such */
  90 #define VRING_HIDDEN_IS_CHAIN   256
  91
  92 /* Virtio ring descriptors: 16 bytes.  These can chain together via "next". */
  93 struct VRingDesc {
  94     /* Address (guest-physical). */
  95     uint64_t addr;
  96     /* Length. */
  97     uint32_t len;
  98     /* The flags as indicated above. */
  99     uint16_t flags;
 100     /* We chain unused descriptors via this, too */
 101     uint16_t next;
 102 } __attribute__((packed));
 103 typedef struct VRingDesc VRingDesc;
 104
 105 struct VRingAvail {
 106     uint16_t flags;
 107     uint16_t idx;
 108     uint16_t ring[];
 109 } __attribute__((packed));
 110 typedef struct VRingAvail VRingAvail;
 111
 112 /* uint32_t is used here for ids for padding reasons. */
 113 struct VRingUsedElem {
 114     /* Index of start of used descriptor chain. */
 115     uint32_t id;
 116     /* Total length of the descriptor chain which was used (written to) */
 117     uint32_t len;
 118 } __attribute__((packed));
 119 typedef struct VRingUsedElem VRingUsedElem;
 120
 121 struct VRingUsed {
 122     uint16_t flags;
 123     uint16_t idx;
 124     VRingUsedElem ring[];
 125 } __attribute__((packed));
 126 typedef struct VRingUsed VRingUsed;
 127
 128 struct VRing {
 129     unsigned int num;
 130     int next_idx;
 131     int used_idx;
 132     VRingDesc *desc;
 133     VRingAvail *avail;
 134     VRingUsed *used;
 135     SubChannelId schid;
 136     long cookie;
 137     int id;
 138 };
 139 typedef struct VRing VRing;
 140
 141
 142 /***********************************************
 143  *               Virtio block                  *
 144  ***********************************************/
 145
 146 /*
 147  * Command types
 148  *
 149  * Usage is a bit tricky as some bits are used as flags and some are not.
 150  *
 151  * Rules:
 152  *   VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or
 153  *   VIRTIO_BLK_T_BARRIER.  VIRTIO_BLK_T_FLUSH is a command of its own
 154  *   and may not be combined with any of the other flags.
 155  */
 156
 157 /* These two define direction. */
 158 #define VIRTIO_BLK_T_IN         0
 159 #define VIRTIO_BLK_T_OUT        1
 160
 161 /* This bit says it's a scsi command, not an actual read or write. */
 162 #define VIRTIO_BLK_T_SCSI_CMD   2
 163
 164 /* Cache flush command */
 165 #define VIRTIO_BLK_T_FLUSH      4
 166
 167 /* Barrier before this op. */
 168 #define VIRTIO_BLK_T_BARRIER    0x80000000
 169
 170 /* This is the first element of the read scatter-gather list. */
 171 struct VirtioBlkOuthdr {
 172         /* VIRTIO_BLK_T* */
 173         uint32_t type;
 174         /* io priority. */
 175         uint32_t ioprio;
 176         /* Sector (ie. 512 byte offset) */
 177         uint64_t sector;
 178 };
 179 typedef struct VirtioBlkOuthdr VirtioBlkOuthdr;
 180
 181 struct VirtioBlkConfig {
 182     uint64_t capacity; /* in 512-byte sectors */
 183     uint32_t size_max; /* max segment size (if VIRTIO_BLK_F_SIZE_MAX) */
 184     uint32_t seg_max;  /* max number of segments (if VIRTIO_BLK_F_SEG_MAX) */
 185
 186     struct VirtioBlkGeometry {
 187         uint16_t cylinders;
 188         uint8_t heads;
 189         uint8_t sectors;
 190     } geometry; /* (if VIRTIO_BLK_F_GEOMETRY) */
 191
 192     uint32_t blk_size; /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
 193
 194     /* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY  */
 195     uint8_t physical_block_exp; /* exponent for physical blk per logical blk */
 196     uint8_t alignment_offset;   /* alignment offset in logical blocks */
 197     uint16_t min_io_size;       /* min I/O size without performance penalty
 198                               in logical blocks */
 199     uint32_t opt_io_size;       /* optimal sustained I/O size in logical blks */
 200
 201     uint8_t wce; /* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */
 202 } __attribute__((packed));
 203 typedef struct VirtioBlkConfig VirtioBlkConfig;
 204
 205 enum guessed_disk_nature_type {
 206     VIRTIO_GDN_NONE     = 0,
 207     VIRTIO_GDN_DASD     = 1,
 208     VIRTIO_GDN_CDROM    = 2,
 209     VIRTIO_GDN_SCSI     = 3,
 210 };
 211 typedef enum guessed_disk_nature_type VirtioGDN;
 212
 213 VirtioGDN virtio_guessed_disk_nature(void);
 214 void virtio_assume_scsi(void);
 215 void virtio_assume_eckd(void);
 216 void virtio_assume_iso9660(void);
 217
 218 extern bool virtio_disk_is_scsi(void);
 219 extern bool virtio_disk_is_eckd(void);
 220 extern bool virtio_ipl_disk_is_valid(void);
 221 extern int virtio_get_block_size(void);
 222 extern uint8_t virtio_get_heads(void);
 223 extern uint8_t virtio_get_sectors(void);
 224 extern uint64_t virtio_get_blocks(void);
 225 extern int virtio_read_many(ulong sector, void *load_addr, int sec_num);
 226
 227 #define VIRTIO_SECTOR_SIZE 512
 228 #define VIRTIO_ISO_BLOCK_SIZE 2048
 229 #define VIRTIO_SCSI_BLOCK_SIZE 512
 230
 231 static inline ulong virtio_sector_adjust(ulong sector)
 232 {
 233     return sector * (virtio_get_block_size() / VIRTIO_SECTOR_SIZE);
 234 }
 235
 236 struct VirtioScsiConfig {
 237     uint32_t num_queues;
 238     uint32_t seg_max;
 239     uint32_t max_sectors;
 240     uint32_t cmd_per_lun;
 241     uint32_t event_info_size;
 242     uint32_t sense_size;
 243     uint32_t cdb_size;
 244     uint16_t max_channel;
 245     uint16_t max_target;
 246     uint32_t max_lun;
 247 } __attribute__((packed));
 248 typedef struct VirtioScsiConfig VirtioScsiConfig;
 249
 250 struct ScsiDevice {
 251     uint16_t channel;   /* Always 0 in QEMU     */
 252     uint16_t target;    /* will be scanned over */
 253     uint32_t lun;       /* will be reported     */
 254 };
 255 typedef struct ScsiDevice ScsiDevice;
 256
 257 struct VDev {
 258     int nr_vqs;
 259     VRing *vrings;
 260     int cmd_vr_idx;
 261     void *ring_area;
 262     long wait_reply_timeout;
 263     VirtioGDN guessed_disk_nature;
 264     SubChannelId schid;
 265     SenseId senseid;
 266     union {
 267         VirtioBlkConfig blk;
 268         VirtioScsiConfig scsi;
 269     } config;
 270     ScsiDevice *scsi_device;
 271     bool is_cdrom;
 272     int scsi_block_size;
 273     int blk_factor;
 274     uint64_t scsi_last_block;
 275     uint32_t scsi_dev_cyls;
 276     uint8_t scsi_dev_heads;
 277     bool scsi_device_selected;
 278     ScsiDevice selected_scsi_device;
 279 };
 280 typedef struct VDev VDev;
 281
 282 VDev *virtio_get_device(void);
 283 VirtioDevType virtio_get_device_type(void);
 284
 285 struct VirtioCmd {
 286     void *data;
 287     int size;
 288     int flags;
 289 };
 290 typedef struct VirtioCmd VirtioCmd;
 291
 292 int virtio_run(VDev *vdev, int vqid, VirtioCmd *cmd);
 293
 294 #endif /* VIRTIO_H */