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Avi Kivity authoredThese are subsumed into the driver constructor/destrutor.
Avi Kivity authoredThese are subsumed into the driver constructor/destrutor.
virtio-blk.hh 6.76 KiB
#ifndef VIRTIO_BLK_DRIVER_H
#define VIRTIO_BLK_DRIVER_H
/* This header is BSD licensed so anyone can use the definitions to implement
* compatible drivers/servers.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of IBM nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE. */
#include "drivers/virtio.hh"
#include "drivers/pci-device.hh"
#include <osv/bio.h>
namespace virtio {
class virtio_blk : public virtio_driver {
public:
// The feature bitmap for virtio blk
enum BlkFeatures {
VIRTIO_BLK_F_BARRIER=0, /* Does host support barriers? */
VIRTIO_BLK_F_SIZE_MAX=1, /* Indicates maximum segment size */
VIRTIO_BLK_F_SEG_MAX=2, /* Indicates maximum # of segments */
VIRTIO_BLK_F_GEOMETRY=4, /* Legacy geometry available */
VIRTIO_BLK_F_RO=5, /* Disk is read-only */
VIRTIO_BLK_F_BLK_SIZE=6, /* Block size of disk is available*/
VIRTIO_BLK_F_SCSI=7, /* Supports scsi command passthru */
VIRTIO_BLK_F_WCE=9, /* Writeback mode enabled after reset */
VIRTIO_BLK_F_TOPOLOGY=10, /* Topology information is available */
VIRTIO_BLK_F_CONFIG_WCE=11, /* Writeback mode available in config */
};
enum {
VIRTIO_BLK_DEVICE_ID=0x1001,
VIRTIO_BLK_ID_BYTES=20, /* ID string length */
/*
* 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.
*/
};
enum virtio_blk_request_type {
VIRTIO_BLK_T_IN=0,
VIRTIO_BLK_T_OUT=1,
/* This bit says it's a scsi command, not an actual read or write. */
VIRTIO_BLK_T_SCSI_CMD=2,
/* Cache flush command */
VIRTIO_BLK_T_FLUSH=4,
/* Get device ID command */
VIRTIO_BLK_T_GET_ID=8,
/* Barrier before this op. */
VIRTIO_BLK_T_BARRIER=0x80000000,
};
enum virtio_blk_res_code {
/* And this is the final byte of the write scatter-gather list. */
VIRTIO_BLK_S_OK=0,
VIRTIO_BLK_S_IOERR=1,
VIRTIO_BLK_S_UNSUPP=2,
};
struct virtio_blk_config {
/* The capacity (in 512-byte sectors). */
u64 capacity;
/* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */
u32 size_max;
/* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */
u32 seg_max;
/* geometry the device (if VIRTIO_BLK_F_GEOMETRY) */
struct virtio_blk_geometry {
u16 cylinders;
u8 heads;
u8 sectors;
} geometry;
/* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
u32 blk_size;
/* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY */
/* exponent for physical block per logical block. */
u8 physical_block_exp;
/* alignment offset in logical blocks. */
u8 alignment_offset;
/* minimum I/O size without performance penalty in logical blocks. */
u16 min_io_size;
/* optimal sustained I/O size in logical blocks. */
u32 opt_io_size;
/* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */
u8 wce;
} __attribute__((packed));
/* 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;
};
struct virtio_scsi_inhdr {
u32 errors;
u32 data_len;
u32 sense_len;
u32 residual;
};
struct virtio_blk_res {
u8 status; };
struct virtio_blk_req {
virtio_blk_req(void* req = nullptr, sglist* sg = nullptr, virtio_blk_res* res = nullptr, struct bio* b=nullptr)
:req_header(req), payload(sg), status(res), bio(b) {};
~virtio_blk_req();
void* req_header;
sglist* payload;
virtio_blk_res* status;
struct bio* bio;
};
explicit virtio_blk(virtio_device* dev);
virtual ~virtio_blk();
virtual const std::string get_name(void) { return _driver_name; }
bool read_config();
virtual u32 get_driver_features(void);
int make_virtio_request(struct bio*);
void response_worker();
int size();
void set_readonly() {_ro = true;}
bool is_readonly() {return _ro;}
static hw_driver* probe(hw_device* dev);
private:
std::string _driver_name;
virtio_blk_config _config;
//maintains the virtio instance number for multiple drives
static int _instance;
int _id;
bool _ro;
};
}
#endif