--- /dev/null
+/*
+ * 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 */
Code Review / kvmfornfv.git / blobdiff