261 lines
7.0 KiB
C
261 lines
7.0 KiB
C
/*
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* Virtio driver bits
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*
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* Copyright (c) 2013 Alexander Graf <agraf@suse.de>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or (at
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* your option) any later version. See the COPYING file in the top-level
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* directory.
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*/
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#ifndef VIRTIO_H
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#define VIRTIO_H
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#include "s390-ccw.h"
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/* Status byte for guest to report progress, and synchronize features. */
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/* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
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#define VIRTIO_CONFIG_S_ACKNOWLEDGE 1
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/* We have found a driver for the device. */
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#define VIRTIO_CONFIG_S_DRIVER 2
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/* Driver has used its parts of the config, and is happy */
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#define VIRTIO_CONFIG_S_DRIVER_OK 4
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/* We've given up on this device. */
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#define VIRTIO_CONFIG_S_FAILED 0x80
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enum VirtioDevType {
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VIRTIO_ID_NET = 1,
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VIRTIO_ID_BLOCK = 2,
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VIRTIO_ID_CONSOLE = 3,
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VIRTIO_ID_BALLOON = 5,
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};
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typedef enum VirtioDevType VirtioDevType;
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struct VirtioDevHeader {
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VirtioDevType type:8;
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uint8_t num_vq;
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uint8_t feature_len;
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uint8_t config_len;
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uint8_t status;
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uint8_t vqconfig[];
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} __attribute__((packed));
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typedef struct VirtioDevHeader VirtioDevHeader;
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struct VirtioVqConfig {
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uint64_t token;
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uint64_t address;
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uint16_t num;
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uint8_t pad[6];
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} __attribute__((packed));
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typedef struct VirtioVqConfig VirtioVqConfig;
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struct VqInfo {
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uint64_t queue;
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uint32_t align;
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uint16_t index;
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uint16_t num;
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} __attribute__((packed));
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typedef struct VqInfo VqInfo;
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struct VqConfig {
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uint16_t index;
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uint16_t num;
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} __attribute__((packed));
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typedef struct VqConfig VqConfig;
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struct VirtioDev {
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VirtioDevHeader *header;
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VirtioVqConfig *vqconfig;
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char *host_features;
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char *guest_features;
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char *config;
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};
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typedef struct VirtioDev VirtioDev;
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#define VIRTIO_RING_SIZE (PAGE_SIZE * 8)
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#define VIRTIO_MAX_VQS 3
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#define KVM_S390_VIRTIO_RING_ALIGN 4096
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#define VRING_USED_F_NO_NOTIFY 1
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/* This marks a buffer as continuing via the next field. */
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#define VRING_DESC_F_NEXT 1
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/* This marks a buffer as write-only (otherwise read-only). */
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#define VRING_DESC_F_WRITE 2
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/* This means the buffer contains a list of buffer descriptors. */
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#define VRING_DESC_F_INDIRECT 4
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/* Internal flag to mark follow-up segments as such */
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#define VRING_HIDDEN_IS_CHAIN 256
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/* Virtio ring descriptors: 16 bytes. These can chain together via "next". */
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struct VRingDesc {
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/* Address (guest-physical). */
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uint64_t addr;
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/* Length. */
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uint32_t len;
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/* The flags as indicated above. */
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uint16_t flags;
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/* We chain unused descriptors via this, too */
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uint16_t next;
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} __attribute__((packed));
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typedef struct VRingDesc VRingDesc;
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struct VRingAvail {
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uint16_t flags;
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uint16_t idx;
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uint16_t ring[];
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} __attribute__((packed));
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typedef struct VRingAvail VRingAvail;
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/* uint32_t is used here for ids for padding reasons. */
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struct VRingUsedElem {
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/* Index of start of used descriptor chain. */
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uint32_t id;
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/* Total length of the descriptor chain which was used (written to) */
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uint32_t len;
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} __attribute__((packed));
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typedef struct VRingUsedElem VRingUsedElem;
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struct VRingUsed {
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uint16_t flags;
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uint16_t idx;
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VRingUsedElem ring[];
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} __attribute__((packed));
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typedef struct VRingUsed VRingUsed;
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struct VRing {
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unsigned int num;
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int next_idx;
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int used_idx;
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VRingDesc *desc;
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VRingAvail *avail;
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VRingUsed *used;
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SubChannelId schid;
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long cookie;
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int id;
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};
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typedef struct VRing VRing;
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/***********************************************
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* Virtio block *
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***********************************************/
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/*
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* Command types
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*
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* Usage is a bit tricky as some bits are used as flags and some are not.
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*
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* Rules:
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* VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or
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* VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own
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* and may not be combined with any of the other flags.
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*/
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/* These two define direction. */
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#define VIRTIO_BLK_T_IN 0
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#define VIRTIO_BLK_T_OUT 1
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/* This bit says it's a scsi command, not an actual read or write. */
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#define VIRTIO_BLK_T_SCSI_CMD 2
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/* Cache flush command */
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#define VIRTIO_BLK_T_FLUSH 4
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/* Barrier before this op. */
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#define VIRTIO_BLK_T_BARRIER 0x80000000
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/* This is the first element of the read scatter-gather list. */
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struct VirtioBlkOuthdr {
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/* VIRTIO_BLK_T* */
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uint32_t type;
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/* io priority. */
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uint32_t ioprio;
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/* Sector (ie. 512 byte offset) */
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uint64_t sector;
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};
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typedef struct VirtioBlkOuthdr VirtioBlkOuthdr;
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struct VirtioBlkConfig {
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uint64_t capacity; /* in 512-byte sectors */
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uint32_t size_max; /* max segment size (if VIRTIO_BLK_F_SIZE_MAX) */
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uint32_t seg_max; /* max number of segments (if VIRTIO_BLK_F_SEG_MAX) */
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struct VirtioBlkGeometry {
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uint16_t cylinders;
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uint8_t heads;
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uint8_t sectors;
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} geometry; /* (if VIRTIO_BLK_F_GEOMETRY) */
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uint32_t blk_size; /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
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/* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY */
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uint8_t physical_block_exp; /* exponent for physical blk per logical blk */
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uint8_t alignment_offset; /* alignment offset in logical blocks */
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uint16_t min_io_size; /* min I/O size without performance penalty
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in logical blocks */
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uint32_t opt_io_size; /* optimal sustained I/O size in logical blks */
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uint8_t wce; /* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */
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} __attribute__((packed));
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typedef struct VirtioBlkConfig VirtioBlkConfig;
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enum guessed_disk_nature_type {
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VIRTIO_GDN_NONE = 0,
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VIRTIO_GDN_DASD = 1,
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VIRTIO_GDN_CDROM = 2,
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VIRTIO_GDN_SCSI = 3,
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};
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typedef enum guessed_disk_nature_type VirtioGDN;
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VirtioGDN virtio_guessed_disk_nature(void);
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void virtio_assume_scsi(void);
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void virtio_assume_eckd(void);
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void virtio_assume_iso9660(void);
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extern bool virtio_disk_is_scsi(void);
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extern bool virtio_disk_is_eckd(void);
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extern bool virtio_ipl_disk_is_valid(void);
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extern int virtio_get_block_size(void);
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extern uint8_t virtio_get_heads(void);
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extern uint8_t virtio_get_sectors(void);
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extern uint64_t virtio_get_blocks(void);
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extern int virtio_read_many(ulong sector, void *load_addr, int sec_num);
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#define VIRTIO_SECTOR_SIZE 512
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static inline ulong virtio_sector_adjust(ulong sector)
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{
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return sector * (virtio_get_block_size() / VIRTIO_SECTOR_SIZE);
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}
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struct VDev {
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int nr_vqs;
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VRing *vrings;
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int cmd_vr_idx;
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void *ring_area;
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long wait_reply_timeout;
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VirtioGDN guessed_disk_nature;
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SubChannelId schid;
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SenseId senseid;
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union {
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VirtioBlkConfig blk;
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} config;
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};
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typedef struct VDev VDev;
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VDev *virtio_get_device(void);
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VirtioDevType virtio_get_device_type(void);
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struct VirtioCmd {
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void *data;
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int size;
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int flags;
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};
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typedef struct VirtioCmd VirtioCmd;
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int virtio_run(VDev *vdev, int vqid, VirtioCmd *cmd);
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#endif /* VIRTIO_H */
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