4 * Copyright (c) 2013 Alexander Graf <agraf@suse.de>
6 * This work is licensed under the terms of the GNU GPL, version 2 or (at
7 * your option) any later version. See the COPYING file in the top-level
16 /* Status byte for guest to report progress, and synchronize features. */
17 /* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
18 #define VIRTIO_CONFIG_S_ACKNOWLEDGE 1
19 /* We have found a driver for the device. */
20 #define VIRTIO_CONFIG_S_DRIVER 2
21 /* Driver has used its parts of the config, and is happy */
22 #define VIRTIO_CONFIG_S_DRIVER_OK 4
23 /* We've given up on this device. */
24 #define VIRTIO_CONFIG_S_FAILED 0x80
29 VIRTIO_ID_CONSOLE
= 3,
30 VIRTIO_ID_BALLOON
= 5,
32 typedef enum VirtioDevType VirtioDevType
;
34 struct VirtioDevHeader
{
41 } __attribute__((packed
));
42 typedef struct VirtioDevHeader VirtioDevHeader
;
44 struct VirtioVqConfig
{
49 } __attribute__((packed
));
50 typedef struct VirtioVqConfig VirtioVqConfig
;
57 } __attribute__((packed
));
58 typedef struct VqInfo VqInfo
;
63 } __attribute__((packed
));
64 typedef struct VqConfig VqConfig
;
67 VirtioDevHeader
*header
;
68 VirtioVqConfig
*vqconfig
;
73 typedef struct VirtioDev VirtioDev
;
75 #define VIRTIO_RING_SIZE (PAGE_SIZE * 8)
76 #define VIRTIO_MAX_VQS 3
77 #define KVM_S390_VIRTIO_RING_ALIGN 4096
79 #define VRING_USED_F_NO_NOTIFY 1
81 /* This marks a buffer as continuing via the next field. */
82 #define VRING_DESC_F_NEXT 1
83 /* This marks a buffer as write-only (otherwise read-only). */
84 #define VRING_DESC_F_WRITE 2
85 /* This means the buffer contains a list of buffer descriptors. */
86 #define VRING_DESC_F_INDIRECT 4
88 /* Internal flag to mark follow-up segments as such */
89 #define VRING_HIDDEN_IS_CHAIN 256
91 /* Virtio ring descriptors: 16 bytes. These can chain together via "next". */
93 /* Address (guest-physical). */
97 /* The flags as indicated above. */
99 /* We chain unused descriptors via this, too */
101 } __attribute__((packed
));
102 typedef struct VRingDesc VRingDesc
;
108 } __attribute__((packed
));
109 typedef struct VRingAvail VRingAvail
;
111 /* uint32_t is used here for ids for padding reasons. */
112 struct VRingUsedElem
{
113 /* Index of start of used descriptor chain. */
115 /* Total length of the descriptor chain which was used (written to) */
117 } __attribute__((packed
));
118 typedef struct VRingUsedElem VRingUsedElem
;
123 VRingUsedElem ring
[];
124 } __attribute__((packed
));
125 typedef struct VRingUsed VRingUsed
;
138 typedef struct VRing VRing
;
141 /***********************************************
143 ***********************************************/
148 * Usage is a bit tricky as some bits are used as flags and some are not.
151 * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or
152 * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own
153 * and may not be combined with any of the other flags.
156 /* These two define direction. */
157 #define VIRTIO_BLK_T_IN 0
158 #define VIRTIO_BLK_T_OUT 1
160 /* This bit says it's a scsi command, not an actual read or write. */
161 #define VIRTIO_BLK_T_SCSI_CMD 2
163 /* Cache flush command */
164 #define VIRTIO_BLK_T_FLUSH 4
166 /* Barrier before this op. */
167 #define VIRTIO_BLK_T_BARRIER 0x80000000
169 /* This is the first element of the read scatter-gather list. */
170 struct VirtioBlkOuthdr
{
175 /* Sector (ie. 512 byte offset) */
178 typedef struct VirtioBlkOuthdr VirtioBlkOuthdr
;
180 struct VirtioBlkConfig
{
181 uint64_t capacity
; /* in 512-byte sectors */
182 uint32_t size_max
; /* max segment size (if VIRTIO_BLK_F_SIZE_MAX) */
183 uint32_t seg_max
; /* max number of segments (if VIRTIO_BLK_F_SEG_MAX) */
185 struct VirtioBlkGeometry
{
189 } geometry
; /* (if VIRTIO_BLK_F_GEOMETRY) */
191 uint32_t blk_size
; /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
193 /* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY */
194 uint8_t physical_block_exp
; /* exponent for physical blk per logical blk */
195 uint8_t alignment_offset
; /* alignment offset in logical blocks */
196 uint16_t min_io_size
; /* min I/O size without performance penalty
198 uint32_t opt_io_size
; /* optimal sustained I/O size in logical blks */
200 uint8_t wce
; /* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */
201 } __attribute__((packed
));
202 typedef struct VirtioBlkConfig VirtioBlkConfig
;
204 enum guessed_disk_nature_type
{
207 VIRTIO_GDN_CDROM
= 2,
210 typedef enum guessed_disk_nature_type VirtioGDN
;
212 VirtioGDN
virtio_guessed_disk_nature(void);
213 void virtio_assume_scsi(void);
214 void virtio_assume_eckd(void);
215 void virtio_assume_iso9660(void);
217 extern bool virtio_disk_is_scsi(void);
218 extern bool virtio_disk_is_eckd(void);
219 extern bool virtio_ipl_disk_is_valid(void);
220 extern int virtio_get_block_size(void);
221 extern uint8_t virtio_get_heads(void);
222 extern uint8_t virtio_get_sectors(void);
223 extern uint64_t virtio_get_blocks(void);
224 extern int virtio_read_many(ulong sector
, void *load_addr
, int sec_num
);
226 #define VIRTIO_SECTOR_SIZE 512
228 static inline ulong
virtio_sector_adjust(ulong sector
)
230 return sector
* (virtio_get_block_size() / VIRTIO_SECTOR_SIZE
);
238 long wait_reply_timeout
;
239 VirtioGDN guessed_disk_nature
;
246 typedef struct VDev VDev
;
248 VDev
*virtio_get_device(void);
249 VirtioDevType
virtio_get_device_type(void);
251 #endif /* VIRTIO_H */