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/*
* 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;
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;
};
#endif /* VIRTIO_H */