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Diffstat (limited to 'pc-bios/s390-ccw/virtio.h')
| -rw-r--r-- | pc-bios/s390-ccw/virtio.h | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/pc-bios/s390-ccw/virtio.h b/pc-bios/s390-ccw/virtio.h new file mode 100644 index 00000000..c23466b8 --- /dev/null +++ b/pc-bios/s390-ccw/virtio.h @@ -0,0 +1,212 @@ +/* + * Virtio driver bits + * + * Copyright (c) 2013 Alexander Graf <agraf@suse.de> + * + * This work is licensed under the terms of the GNU GPL, version 2 or (at + * your option) any later version. See the COPYING file in the top-level + * directory. + */ + +#ifndef VIRTIO_H +#define VIRTIO_H + +#include "s390-ccw.h" + +/* Status byte for guest to report progress, and synchronize features. */ +/* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */ +#define VIRTIO_CONFIG_S_ACKNOWLEDGE 1 +/* We have found a driver for the device. */ +#define VIRTIO_CONFIG_S_DRIVER 2 +/* Driver has used its parts of the config, and is happy */ +#define VIRTIO_CONFIG_S_DRIVER_OK 4 +/* We've given up on this device. */ +#define VIRTIO_CONFIG_S_FAILED 0x80 + +enum virtio_dev_type { + VIRTIO_ID_NET = 1, + VIRTIO_ID_BLOCK = 2, + VIRTIO_ID_CONSOLE = 3, + VIRTIO_ID_BALLOON = 5, +}; + +struct virtio_dev_header { + enum virtio_dev_type type : 8; + u8 num_vq; + u8 feature_len; + u8 config_len; + u8 status; + u8 vqconfig[]; +} __attribute__((packed)); + +struct virtio_vqconfig { + u64 token; + u64 address; + u16 num; + u8 pad[6]; +} __attribute__((packed)); + +struct vq_info_block { + u64 queue; + u32 align; + u16 index; + u16 num; +} __attribute__((packed)); + +struct vq_config_block { + u16 index; + u16 num; +} __attribute__((packed)); + +struct virtio_dev { + struct virtio_dev_header *header; + struct virtio_vqconfig *vqconfig; + char *host_features; + char *guest_features; + char *config; +}; + +#define KVM_S390_VIRTIO_RING_ALIGN 4096 + +#define VRING_USED_F_NO_NOTIFY 1 + +/* This marks a buffer as continuing via the next field. */ +#define VRING_DESC_F_NEXT 1 +/* This marks a buffer as write-only (otherwise read-only). */ +#define VRING_DESC_F_WRITE 2 +/* This means the buffer contains a list of buffer descriptors. */ +#define VRING_DESC_F_INDIRECT 4 + +/* Internal flag to mark follow-up segments as such */ +#define VRING_HIDDEN_IS_CHAIN 256 + +/* Virtio ring descriptors: 16 bytes. These can chain together via "next". */ +struct vring_desc { + /* Address (guest-physical). */ + u64 addr; + /* Length. */ + u32 len; + /* The flags as indicated above. */ + u16 flags; + /* We chain unused descriptors via this, too */ + u16 next; +} __attribute__((packed)); + +struct vring_avail { + u16 flags; + u16 idx; + u16 ring[]; +} __attribute__((packed)); + +/* u32 is used here for ids for padding reasons. */ +struct vring_used_elem { + /* Index of start of used descriptor chain. */ + u32 id; + /* Total length of the descriptor chain which was used (written to) */ + u32 len; +} __attribute__((packed)); + +struct vring_used { + u16 flags; + u16 idx; + struct vring_used_elem ring[]; +} __attribute__((packed)); + +struct vring { + unsigned int num; + int next_idx; + int used_idx; + struct vring_desc *desc; + struct vring_avail *avail; + struct vring_used *used; + struct subchannel_id schid; +}; + + +/*********************************************** + * Virtio block * + ***********************************************/ + +/* + * Command types + * + * Usage is a bit tricky as some bits are used as flags and some are not. + * + * Rules: + * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or + * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own + * and may not be combined with any of the other flags. + */ + +/* These two define direction. */ +#define VIRTIO_BLK_T_IN 0 +#define VIRTIO_BLK_T_OUT 1 + +/* This bit says it's a scsi command, not an actual read or write. */ +#define VIRTIO_BLK_T_SCSI_CMD 2 + +/* Cache flush command */ +#define VIRTIO_BLK_T_FLUSH 4 + +/* Barrier before this op. */ +#define VIRTIO_BLK_T_BARRIER 0x80000000 + +/* This is the first element of the read scatter-gather list. */ +struct virtio_blk_outhdr { + /* VIRTIO_BLK_T* */ + u32 type; + /* io priority. */ + u32 ioprio; + /* Sector (ie. 512 byte offset) */ + u64 sector; +}; + +typedef struct VirtioBlkConfig { + u64 capacity; /* in 512-byte sectors */ + u32 size_max; /* max segment size (if VIRTIO_BLK_F_SIZE_MAX) */ + u32 seg_max; /* max number of segments (if VIRTIO_BLK_F_SEG_MAX) */ + + struct virtio_blk_geometry { + u16 cylinders; + u8 heads; + u8 sectors; + } geometry; /* (if VIRTIO_BLK_F_GEOMETRY) */ + + u32 blk_size; /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ + + /* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY */ + u8 physical_block_exp; /* exponent for physical block per logical block */ + u8 alignment_offset; /* alignment offset in logical blocks */ + u16 min_io_size; /* min I/O size without performance penalty + in logical blocks */ + u32 opt_io_size; /* optimal sustained I/O size in logical blocks */ + + u8 wce; /* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */ +} __attribute__((packed)) VirtioBlkConfig; + +bool virtio_guessed_disk_nature(void); +void virtio_assume_scsi(void); +void virtio_assume_eckd(void); + +extern bool virtio_disk_is_scsi(void); +extern bool virtio_disk_is_eckd(void); +extern bool virtio_ipl_disk_is_valid(void); +extern int virtio_get_block_size(void); +extern uint8_t virtio_get_heads(void); +extern uint8_t virtio_get_sectors(void); +extern uint64_t virtio_get_blocks(void); +extern int virtio_read_many(ulong sector, void *load_addr, int sec_num); + +#define VIRTIO_SECTOR_SIZE 512 + +static inline ulong virtio_eckd_sector_adjust(ulong sector) +{ + return sector * (virtio_get_block_size() / VIRTIO_SECTOR_SIZE); +} + +static inline ulong virtio_sector_adjust(ulong sector) +{ + return virtio_disk_is_eckd() ? virtio_eckd_sector_adjust(sector) : sector; +} + +#endif /* VIRTIO_H */ |