/* * Virtio driver bits * * Copyright (c) 2013 Alexander Graf * * 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 VirtioDevType { VIRTIO_ID_NET = 1, VIRTIO_ID_BLOCK = 2, VIRTIO_ID_CONSOLE = 3, VIRTIO_ID_BALLOON = 5, }; typedef enum VirtioDevType VirtioDevType; struct VirtioDevHeader { VirtioDevType type:8; uint8_t num_vq; uint8_t feature_len; uint8_t config_len; uint8_t status; uint8_t vqconfig[]; } __attribute__((packed)); typedef struct VirtioDevHeader VirtioDevHeader; struct VirtioVqConfig { uint64_t token; uint64_t address; uint16_t num; uint8_t pad[6]; } __attribute__((packed)); typedef struct VirtioVqConfig VirtioVqConfig; struct VqInfo { uint64_t queue; uint32_t align; uint16_t index; uint16_t num; } __attribute__((packed)); typedef struct VqInfo VqInfo; struct VqConfig { uint16_t index; uint16_t num; } __attribute__((packed)); typedef struct VqConfig VqConfig; struct VirtioDev { VirtioDevHeader *header; VirtioVqConfig *vqconfig; char *host_features; char *guest_features; char *config; }; typedef struct VirtioDev VirtioDev; #define VIRTIO_RING_SIZE (PAGE_SIZE * 8) #define VIRTIO_MAX_VQS 3 #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 VRingDesc { /* Address (guest-physical). */ uint64_t addr; /* Length. */ uint32_t len; /* The flags as indicated above. */ uint16_t flags; /* We chain unused descriptors via this, too */ uint16_t next; } __attribute__((packed)); typedef struct VRingDesc VRingDesc; struct VRingAvail { uint16_t flags; uint16_t idx; uint16_t ring[]; } __attribute__((packed)); typedef struct VRingAvail VRingAvail; /* uint32_t is used here for ids for padding reasons. */ struct VRingUsedElem { /* Index of start of used descriptor chain. */ uint32_t id; /* Total length of the descriptor chain which was used (written to) */ uint32_t len; } __attribute__((packed)); typedef struct VRingUsedElem VRingUsedElem; struct VRingUsed { uint16_t flags; uint16_t idx; VRingUsedElem ring[]; } __attribute__((packed)); typedef struct VRingUsed VRingUsed; struct VRing { unsigned int num; int next_idx; int used_idx; VRingDesc *desc; VRingAvail *avail; VRingUsed *used; SubChannelId schid; long cookie; int id; }; typedef struct VRing VRing; /*********************************************** * 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 VirtioBlkOuthdr { /* VIRTIO_BLK_T* */ uint32_t type; /* io priority. */ uint32_t ioprio; /* Sector (ie. 512 byte offset) */ uint64_t sector; }; typedef struct VirtioBlkOuthdr VirtioBlkOuthdr; struct VirtioBlkConfig { uint64_t capacity; /* in 512-byte sectors */ uint32_t size_max; /* max segment size (if VIRTIO_BLK_F_SIZE_MAX) */ uint32_t seg_max; /* max number of segments (if VIRTIO_BLK_F_SEG_MAX) */ struct VirtioBlkGeometry { uint16_t cylinders; uint8_t heads; uint8_t sectors; } geometry; /* (if VIRTIO_BLK_F_GEOMETRY) */ uint32_t blk_size; /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ /* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY */ uint8_t physical_block_exp; /* exponent for physical blk per logical blk */ uint8_t alignment_offset; /* alignment offset in logical blocks */ uint16_t min_io_size; /* min I/O size without performance penalty in logical blocks */ uint32_t opt_io_size; /* optimal sustained I/O size in logical blks */ uint8_t wce; /* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */ } __attribute__((packed)); typedef struct VirtioBlkConfig VirtioBlkConfig; bool virtio_guessed_disk_nature(void); void virtio_assume_scsi(void); void virtio_assume_eckd(void); void virtio_assume_iso9660(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_sector_adjust(ulong sector) { return sector * (virtio_get_block_size() / VIRTIO_SECTOR_SIZE); } struct VDev { int nr_vqs; VRing *vrings; int cmd_vr_idx; void *ring_area; long wait_reply_timeout; bool guessed_disk_nature; SubChannelId schid; SenseId senseid; union { VirtioBlkConfig blk; } config; }; typedef struct VDev VDev; VDev *virtio_get_device(void); VirtioDevType virtio_get_device_type(void); #endif /* VIRTIO_H */