[qemu.git] / hw / virtio-blk.c

/*
 * Virtio Block Device
 *
 * Copyright IBM, Corp. 2007
 *
 * Authors:
 *  Anthony Liguori   <aliguori@us.ibm.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 *
 */

#include <qemu-common.h>
#include <sysemu.h>
#include "virtio-blk.h"
#include "block_int.h"
#ifdef __linux__
# include <scsi/sg.h>
#endif

typedef struct VirtIOBlock
{
    VirtIODevice vdev;
    BlockDriverState *bs;
    VirtQueue *vq;
    void *rq;
    char serial_str[BLOCK_SERIAL_STRLEN + 1];
} VirtIOBlock;

static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev)
{
    return (VirtIOBlock *)vdev;
}

/* store identify data in little endian format
 */
static inline void put_le16(uint16_t *p, unsigned int v)
{
    *p = cpu_to_le16(v);
}

/* copy to *dst from *src, nul pad dst tail as needed to len bytes
 */
static inline void padstr(char *dst, const char *src, int len)
{
    while (len--)
        *dst++ = *src ? *src++ : '\0';
}

/* setup simulated identify data as appropriate for virtio block device
 *
 * ref: AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS)
 */
static inline void virtio_identify_template(struct virtio_blk_config *bc)
{
    uint16_t *p = &bc->identify[0];
    uint64_t lba_sectors = bc->capacity;

    memset(p, 0, sizeof(bc->identify));
    put_le16(p + 0, 0x0);                            /* ATA device */
    padstr((char *)(p + 23), QEMU_VERSION, 8);       /* firmware revision */
    padstr((char *)(p + 27), "QEMU VIRT_BLK", 40);   /* model# */
    put_le16(p + 47, 0x80ff);                        /* max xfer 255 sectors */
    put_le16(p + 49, 0x0b00);                        /* support IORDY/LBA/DMA */
    put_le16(p + 59, 0x1ff);                         /* cur xfer 255 sectors */
    put_le16(p + 80, 0x1f0);                         /* support ATA8/7/6/5/4 */
    put_le16(p + 81, 0x16);
    put_le16(p + 82, 0x400);
    put_le16(p + 83, 0x400);
    put_le16(p + 100, lba_sectors);
    put_le16(p + 101, lba_sectors >> 16);
    put_le16(p + 102, lba_sectors >> 32);
    put_le16(p + 103, lba_sectors >> 48);
}

typedef struct VirtIOBlockReq
{
    VirtIOBlock *dev;
    VirtQueueElement elem;
    struct virtio_blk_inhdr *in;
    struct virtio_blk_outhdr *out;
    struct virtio_scsi_inhdr *scsi;
    QEMUIOVector qiov;
    struct VirtIOBlockReq *next;
} VirtIOBlockReq;

static void virtio_blk_req_complete(VirtIOBlockReq *req, int status)
{
    VirtIOBlock *s = req->dev;

    req->in->status = status;
    virtqueue_push(s->vq, &req->elem, req->qiov.size + sizeof(*req->in));
    virtio_notify(&s->vdev, s->vq);

    qemu_free(req);
}

static int virtio_blk_handle_write_error(VirtIOBlockReq *req, int error)
{
    BlockInterfaceErrorAction action = drive_get_onerror(req->dev->bs);
    VirtIOBlock *s = req->dev;

    if (action == BLOCK_ERR_IGNORE)
        return 0;

    if ((error == ENOSPC && action == BLOCK_ERR_STOP_ENOSPC)
            || action == BLOCK_ERR_STOP_ANY) {
        req->next = s->rq;
        s->rq = req;
        vm_stop(0);
    } else {
        virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
    }

    return 1;
}

static void virtio_blk_rw_complete(void *opaque, int ret)
{
    VirtIOBlockReq *req = opaque;

    if (ret && (req->out->type & VIRTIO_BLK_T_OUT)) {
        if (virtio_blk_handle_write_error(req, -ret))
            return;
    }

    virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
}

static VirtIOBlockReq *virtio_blk_alloc_request(VirtIOBlock *s)
{
    VirtIOBlockReq *req = qemu_mallocz(sizeof(*req));
    req->dev = s;
    return req;
}

static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s)
{
    VirtIOBlockReq *req = virtio_blk_alloc_request(s);

    if (req != NULL) {
        if (!virtqueue_pop(s->vq, &req->elem)) {
            qemu_free(req);
            return NULL;
        }
    }

    return req;
}

#ifdef __linux__
static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
{
    struct sg_io_hdr hdr;
    int ret, size = 0;
    int status;
    int i;

    /*
     * We require at least one output segment each for the virtio_blk_outhdr
     * and the SCSI command block.
     *
     * We also at least require the virtio_blk_inhdr, the virtio_scsi_inhdr
     * and the sense buffer pointer in the input segments.
     */
    if (req->elem.out_num < 2 || req->elem.in_num < 3) {
        virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
        return;
    }

    /*
     * No support for bidirection commands yet.
     */
    if (req->elem.out_num > 2 && req->elem.in_num > 3) {
        virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
        return;
    }

    /*
     * The scsi inhdr is placed in the second-to-last input segment, just
     * before the regular inhdr.
     */
    req->scsi = (void *)req->elem.in_sg[req->elem.in_num - 2].iov_base;
    size = sizeof(*req->in) + sizeof(*req->scsi);

    memset(&hdr, 0, sizeof(struct sg_io_hdr));
    hdr.interface_id = 'S';
    hdr.cmd_len = req->elem.out_sg[1].iov_len;
    hdr.cmdp = req->elem.out_sg[1].iov_base;
    hdr.dxfer_len = 0;

    if (req->elem.out_num > 2) {
        /*
         * If there are more than the minimally required 2 output segments
         * there is write payload starting from the third iovec.
         */
        hdr.dxfer_direction = SG_DXFER_TO_DEV;
        hdr.iovec_count = req->elem.out_num - 2;

        for (i = 0; i < hdr.iovec_count; i++)
            hdr.dxfer_len += req->elem.out_sg[i + 2].iov_len;

        hdr.dxferp = req->elem.out_sg + 2;

    } else if (req->elem.in_num > 3) {
        /*
         * If we have more than 3 input segments the guest wants to actually
         * read data.
         */
        hdr.dxfer_direction = SG_DXFER_FROM_DEV;
        hdr.iovec_count = req->elem.in_num - 3;
        for (i = 0; i < hdr.iovec_count; i++)
            hdr.dxfer_len += req->elem.in_sg[i].iov_len;

        hdr.dxferp = req->elem.in_sg;
        size += hdr.dxfer_len;
    } else {
        /*
         * Some SCSI commands don't actually transfer any data.
         */
        hdr.dxfer_direction = SG_DXFER_NONE;
    }

    hdr.sbp = req->elem.in_sg[req->elem.in_num - 3].iov_base;
    hdr.mx_sb_len = req->elem.in_sg[req->elem.in_num - 3].iov_len;
    size += hdr.mx_sb_len;

    ret = bdrv_ioctl(req->dev->bs, SG_IO, &hdr);
    if (ret) {
        status = VIRTIO_BLK_S_UNSUPP;
        hdr.status = ret;
        hdr.resid = hdr.dxfer_len;
    } else if (hdr.status) {
        status = VIRTIO_BLK_S_IOERR;
    } else {
        status = VIRTIO_BLK_S_OK;
    }

    req->scsi->errors = hdr.status;
    req->scsi->residual = hdr.resid;
    req->scsi->sense_len = hdr.sb_len_wr;
    req->scsi->data_len = hdr.dxfer_len;

    virtio_blk_req_complete(req, status);
}
#else
static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
{
    virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
}
#endif /* __linux__ */

static void virtio_blk_handle_write(VirtIOBlockReq *req)
{
    bdrv_aio_writev(req->dev->bs, req->out->sector, &req->qiov,
                    req->qiov.size / 512, virtio_blk_rw_complete, req);
}

static void virtio_blk_handle_read(VirtIOBlockReq *req)
{
    bdrv_aio_readv(req->dev->bs, req->out->sector, &req->qiov,
                   req->qiov.size / 512, virtio_blk_rw_complete, req);
}

static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
    VirtIOBlock *s = to_virtio_blk(vdev);
    VirtIOBlockReq *req;

    while ((req = virtio_blk_get_request(s))) {
        if (req->elem.out_num < 1 || req->elem.in_num < 1) {
            fprintf(stderr, "virtio-blk missing headers\n");
            exit(1);
        }

        if (req->elem.out_sg[0].iov_len < sizeof(*req->out) ||
            req->elem.in_sg[req->elem.in_num - 1].iov_len < sizeof(*req->in)) {
            fprintf(stderr, "virtio-blk header not in correct element\n");
            exit(1);
        }

        req->out = (void *)req->elem.out_sg[0].iov_base;
        req->in = (void *)req->elem.in_sg[req->elem.in_num - 1].iov_base;

        if (req->out->type & VIRTIO_BLK_T_SCSI_CMD) {
            virtio_blk_handle_scsi(req);
        } else if (req->out->type & VIRTIO_BLK_T_OUT) {
            qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1],
                                     req->elem.out_num - 1);
            virtio_blk_handle_write(req);
        } else {
            qemu_iovec_init_external(&req->qiov, &req->elem.in_sg[0],
                                     req->elem.in_num - 1);
            virtio_blk_handle_read(req);
        }
    }
    /*
     * FIXME: Want to check for completions before returning to guest mode,
     * so cached reads and writes are reported as quickly as possible. But
     * that should be done in the generic block layer.
     */
}

static void virtio_blk_dma_restart_cb(void *opaque, int running, int reason)
{
    VirtIOBlock *s = opaque;
    VirtIOBlockReq *req = s->rq;

    if (!running)
        return;

    s->rq = NULL;

    while (req) {
        virtio_blk_handle_write(req);
        req = req->next;
    }
}

static void virtio_blk_reset(VirtIODevice *vdev)
{
    /*
     * This should cancel pending requests, but can't do nicely until there
     * are per-device request lists.
     */
    qemu_aio_flush();
}

/* coalesce internal state, copy to pci i/o region 0
 */
static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config)
{
    VirtIOBlock *s = to_virtio_blk(vdev);
    struct virtio_blk_config blkcfg;
    uint64_t capacity;
    int cylinders, heads, secs;

    bdrv_get_geometry(s->bs, &capacity);
    bdrv_get_geometry_hint(s->bs, &cylinders, &heads, &secs);
    memset(&blkcfg, 0, sizeof(blkcfg));
    stq_raw(&blkcfg.capacity, capacity);
    stl_raw(&blkcfg.seg_max, 128 - 2);
    stw_raw(&blkcfg.cylinders, cylinders);
    blkcfg.heads = heads;
    blkcfg.sectors = secs;
    blkcfg.size_max = 0;
    virtio_identify_template(&blkcfg);
    memcpy(&blkcfg.identify[VIRTIO_BLK_ID_SN], s->serial_str,
        VIRTIO_BLK_ID_SN_BYTES);
    memcpy(config, &blkcfg, sizeof(blkcfg));
}

static uint32_t virtio_blk_get_features(VirtIODevice *vdev)
{
    VirtIOBlock *s = to_virtio_blk(vdev);
    uint32_t features = 0;

    features |= (1 << VIRTIO_BLK_F_SEG_MAX);
    features |= (1 << VIRTIO_BLK_F_GEOMETRY);
#ifdef __linux__
    features |= (1 << VIRTIO_BLK_F_SCSI);
#endif
    if (strcmp(s->serial_str, "0"))
        features |= 1 << VIRTIO_BLK_F_IDENTIFY;

    return features;
}

static void virtio_blk_save(QEMUFile *f, void *opaque)
{
    VirtIOBlock *s = opaque;
    VirtIOBlockReq *req = s->rq;

    virtio_save(&s->vdev, f);
    
    while (req) {
        qemu_put_sbyte(f, 1);
        qemu_put_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem));
        req = req->next;
    }
    qemu_put_sbyte(f, 0);
}

static int virtio_blk_load(QEMUFile *f, void *opaque, int version_id)
{
    VirtIOBlock *s = opaque;

    if (version_id != 2)
        return -EINVAL;

    virtio_load(&s->vdev, f);
    while (qemu_get_sbyte(f)) {
        VirtIOBlockReq *req = virtio_blk_alloc_request(s);
        qemu_get_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem));
        req->next = s->rq;
        s->rq = req->next;
    }

    return 0;
}

VirtIODevice *virtio_blk_init(DeviceState *dev)
{
    VirtIOBlock *s;
    int cylinders, heads, secs;
    static int virtio_blk_id;
    BlockDriverState *bs;
    char *ps;

    s = (VirtIOBlock *)virtio_common_init("virtio-blk", VIRTIO_ID_BLOCK,
                                          sizeof(struct virtio_blk_config),
                                          sizeof(VirtIOBlock));

    bs = qdev_init_bdrv(dev, IF_VIRTIO);
    s->vdev.get_config = virtio_blk_update_config;
    s->vdev.get_features = virtio_blk_get_features;
    s->vdev.reset = virtio_blk_reset;
    s->bs = bs;
    s->rq = NULL;
    if (strlen(ps = (char *)drive_get_serial(bs)))
        strncpy(s->serial_str, ps, sizeof(s->serial_str));
    else
        snprintf(s->serial_str, sizeof(s->serial_str), "0");
    bs->private = dev;
    bdrv_guess_geometry(s->bs, &cylinders, &heads, &secs);
    bdrv_set_geometry_hint(s->bs, cylinders, heads, secs);

    s->vq = virtio_add_queue(&s->vdev, 128, virtio_blk_handle_output);

    qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
    register_savevm("virtio-blk", virtio_blk_id++, 2,
                    virtio_blk_save, virtio_blk_load, s);

    return &s->vdev;
}
Commit	Line	Data
6e02c38d AL	1	/*
	2	* Virtio Block Device
	3	*
	4	* Copyright IBM, Corp. 2007
	5	*
	6	* Authors:
	7	* Anthony Liguori <aliguori@us.ibm.com>
	8	*
	9	* This work is licensed under the terms of the GNU GPL, version 2. See
	10	* the COPYING file in the top-level directory.
	11	*
	12	*/
	13
869a5c6d AL	14	#include <qemu-common.h>
869a5c6d AL	15	#include <sysemu.h>
6e02c38d AL	16	#include "virtio-blk.h"
6e02c38d AL	17	#include "block_int.h"
1063b8b1 CH	18	#ifdef __linux__
	19	# include <scsi/sg.h>
	20	#endif
6e02c38d AL	21
	22	typedef struct VirtIOBlock
	23	{
	24	VirtIODevice vdev;
	25	BlockDriverState *bs;
	26	VirtQueue *vq;
869a5c6d	27	void *rq;
bf011293	28	char serial_str[BLOCK_SERIAL_STRLEN + 1];
6e02c38d AL	29	} VirtIOBlock;
	30
	31	static VirtIOBlock to_virtio_blk(VirtIODevice vdev)
	32	{
	33	return (VirtIOBlock *)vdev;
	34	}
	35
bf011293	36	/* store identify data in little endian format
	37	*/
	38	static inline void put_le16(uint16_t *p, unsigned int v)
	39	{
	40	*p = cpu_to_le16(v);
	41	}
	42
	43	/* copy to dst from src, nul pad dst tail as needed to len bytes
	44	*/
	45	static inline void padstr(char dst, const char src, int len)
	46	{
	47	while (len--)
	48	dst++ = src ? *src++ : '\0';
	49	}
	50
	51	/* setup simulated identify data as appropriate for virtio block device
	52	*
	53	* ref: AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS)
	54	*/
	55	static inline void virtio_identify_template(struct virtio_blk_config *bc)
	56	{
	57	uint16_t *p = &bc->identify[0];
	58	uint64_t lba_sectors = bc->capacity;
	59
	60	memset(p, 0, sizeof(bc->identify));
	61	put_le16(p + 0, 0x0); /* ATA device */
	62	padstr((char )(p + 23), QEMU_VERSION, 8); / firmware revision */
	63	padstr((char )(p + 27), "QEMU VIRT_BLK", 40); / model# */
	64	put_le16(p + 47, 0x80ff); /* max xfer 255 sectors */
	65	put_le16(p + 49, 0x0b00); /* support IORDY/LBA/DMA */
	66	put_le16(p + 59, 0x1ff); /* cur xfer 255 sectors */
	67	put_le16(p + 80, 0x1f0); /* support ATA8/7/6/5/4 */
	68	put_le16(p + 81, 0x16);
	69	put_le16(p + 82, 0x400);
	70	put_le16(p + 83, 0x400);
	71	put_le16(p + 100, lba_sectors);
	72	put_le16(p + 101, lba_sectors >> 16);
	73	put_le16(p + 102, lba_sectors >> 32);
	74	put_le16(p + 103, lba_sectors >> 48);
	75	}
	76
6e02c38d AL	77	typedef struct VirtIOBlockReq
	78	{
	79	VirtIOBlock *dev;
	80	VirtQueueElement elem;
	81	struct virtio_blk_inhdr *in;
	82	struct virtio_blk_outhdr *out;
1063b8b1	83	struct virtio_scsi_inhdr *scsi;
d28a1b6e	84	QEMUIOVector qiov;
869a5c6d	85	struct VirtIOBlockReq *next;
6e02c38d AL	86	} VirtIOBlockReq;
6e02c38d AL	87
869a5c6d AL	88	static void virtio_blk_req_complete(VirtIOBlockReq *req, int status)
	89	{
	90	VirtIOBlock *s = req->dev;
	91
	92	req->in->status = status;
d28a1b6e	93	virtqueue_push(s->vq, &req->elem, req->qiov.size + sizeof(*req->in));
869a5c6d AL	94	virtio_notify(&s->vdev, s->vq);
869a5c6d AL	95
869a5c6d AL	96	qemu_free(req);
	97	}
	98
	99	static int virtio_blk_handle_write_error(VirtIOBlockReq *req, int error)
	100	{
	101	BlockInterfaceErrorAction action = drive_get_onerror(req->dev->bs);
	102	VirtIOBlock *s = req->dev;
	103
	104	if (action == BLOCK_ERR_IGNORE)
	105	return 0;
	106
	107	if ((error == ENOSPC && action == BLOCK_ERR_STOP_ENOSPC)
	108	\|\| action == BLOCK_ERR_STOP_ANY) {
	109	req->next = s->rq;
	110	s->rq = req;
	111	vm_stop(0);
	112	} else {
	113	virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
	114	}
	115
	116	return 1;
	117	}
	118
6e02c38d AL	119	static void virtio_blk_rw_complete(void *opaque, int ret)
	120	{
	121	VirtIOBlockReq *req = opaque;
6e02c38d	122
d28a1b6e	123	if (ret && (req->out->type & VIRTIO_BLK_T_OUT)) {
869a5c6d AL	124	if (virtio_blk_handle_write_error(req, -ret))
869a5c6d AL	125	return;
6e02c38d AL	126	}
6e02c38d AL	127
869a5c6d AL	128	virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
869a5c6d AL	129	}
6e02c38d	130
869a5c6d AL	131	static VirtIOBlockReq virtio_blk_alloc_request(VirtIOBlock s)
	132	{
	133	VirtIOBlockReq req = qemu_mallocz(sizeof(req));
487414f1	134	req->dev = s;
869a5c6d	135	return req;
6e02c38d AL	136	}
	137
	138	static VirtIOBlockReq virtio_blk_get_request(VirtIOBlock s)
	139	{
869a5c6d	140	VirtIOBlockReq *req = virtio_blk_alloc_request(s);
6e02c38d	141
869a5c6d AL	142	if (req != NULL) {
	143	if (!virtqueue_pop(s->vq, &req->elem)) {
	144	qemu_free(req);
	145	return NULL;
	146	}
6e02c38d AL	147	}
	148
	149	return req;
	150	}
	151
1063b8b1 CH	152	#ifdef __linux__
	153	static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
	154	{
	155	struct sg_io_hdr hdr;
	156	int ret, size = 0;
	157	int status;
	158	int i;
	159
	160	/*
	161	* We require at least one output segment each for the virtio_blk_outhdr
	162	* and the SCSI command block.
	163	*
	164	* We also at least require the virtio_blk_inhdr, the virtio_scsi_inhdr
	165	* and the sense buffer pointer in the input segments.
	166	*/
	167	if (req->elem.out_num < 2 \|\| req->elem.in_num < 3) {
	168	virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
	169	return;
	170	}
	171
	172	/*
	173	* No support for bidirection commands yet.
	174	*/
	175	if (req->elem.out_num > 2 && req->elem.in_num > 3) {
	176	virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
	177	return;
	178	}
	179
	180	/*
	181	* The scsi inhdr is placed in the second-to-last input segment, just
	182	* before the regular inhdr.
	183	*/
	184	req->scsi = (void *)req->elem.in_sg[req->elem.in_num - 2].iov_base;
	185	size = sizeof(req->in) + sizeof(req->scsi);
	186
	187	memset(&hdr, 0, sizeof(struct sg_io_hdr));
	188	hdr.interface_id = 'S';
	189	hdr.cmd_len = req->elem.out_sg[1].iov_len;
	190	hdr.cmdp = req->elem.out_sg[1].iov_base;
	191	hdr.dxfer_len = 0;
	192
	193	if (req->elem.out_num > 2) {
	194	/*
	195	* If there are more than the minimally required 2 output segments
	196	* there is write payload starting from the third iovec.
	197	*/
	198	hdr.dxfer_direction = SG_DXFER_TO_DEV;
	199	hdr.iovec_count = req->elem.out_num - 2;
	200
	201	for (i = 0; i < hdr.iovec_count; i++)
	202	hdr.dxfer_len += req->elem.out_sg[i + 2].iov_len;
	203
	204	hdr.dxferp = req->elem.out_sg + 2;
	205
	206	} else if (req->elem.in_num > 3) {
	207	/*
	208	* If we have more than 3 input segments the guest wants to actually
	209	* read data.
	210	*/
	211	hdr.dxfer_direction = SG_DXFER_FROM_DEV;
	212	hdr.iovec_count = req->elem.in_num - 3;
	213	for (i = 0; i < hdr.iovec_count; i++)
	214	hdr.dxfer_len += req->elem.in_sg[i].iov_len;
	215
216	hdr.dxferp = req->elem.in_sg;
217	size += hdr.dxfer_len;
218	} else {
219	/*
220	* Some SCSI commands don't actually transfer any data.
221	*/
222	hdr.dxfer_direction = SG_DXFER_NONE;
223	}
224
225	hdr.sbp = req->elem.in_sg[req->elem.in_num - 3].iov_base;
226	hdr.mx_sb_len = req->elem.in_sg[req->elem.in_num - 3].iov_len;
227	size += hdr.mx_sb_len;
228
229	ret = bdrv_ioctl(req->dev->bs, SG_IO, &hdr);
230	if (ret) {
231	status = VIRTIO_BLK_S_UNSUPP;
232	hdr.status = ret;
233	hdr.resid = hdr.dxfer_len;
234	} else if (hdr.status) {
235	status = VIRTIO_BLK_S_IOERR;
236	} else {
237	status = VIRTIO_BLK_S_OK;
238	}
239
240	req->scsi->errors = hdr.status;
241	req->scsi->residual = hdr.resid;
242	req->scsi->sense_len = hdr.sb_len_wr;
243	req->scsi->data_len = hdr.dxfer_len;
244
245	virtio_blk_req_complete(req, status);
246	}
247	#else
248	static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
249	{
250	virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
251	}
252	#endif /* __linux__ */
253
d28a1b6e	254	static void virtio_blk_handle_write(VirtIOBlockReq *req)
869a5c6d	255	{
d28a1b6e AL	256	bdrv_aio_writev(req->dev->bs, req->out->sector, &req->qiov,
	257	req->qiov.size / 512, virtio_blk_rw_complete, req);
	258	}
869a5c6d	259
d28a1b6e AL	260	static void virtio_blk_handle_read(VirtIOBlockReq *req)
	261	{
	262	bdrv_aio_readv(req->dev->bs, req->out->sector, &req->qiov,
	263	req->qiov.size / 512, virtio_blk_rw_complete, req);
869a5c6d AL	264	}
869a5c6d AL	265
6e02c38d AL	266	static void virtio_blk_handle_output(VirtIODevice vdev, VirtQueue vq)
	267	{
	268	VirtIOBlock *s = to_virtio_blk(vdev);
	269	VirtIOBlockReq *req;
	270
	271	while ((req = virtio_blk_get_request(s))) {
6e02c38d AL	272	if (req->elem.out_num < 1 \|\| req->elem.in_num < 1) {
	273	fprintf(stderr, "virtio-blk missing headers\n");
	274	exit(1);
	275	}
	276
	277	if (req->elem.out_sg[0].iov_len < sizeof(*req->out) \|\|
	278	req->elem.in_sg[req->elem.in_num - 1].iov_len < sizeof(*req->in)) {
	279	fprintf(stderr, "virtio-blk header not in correct element\n");
	280	exit(1);
	281	}
	282
	283	req->out = (void *)req->elem.out_sg[0].iov_base;
	284	req->in = (void *)req->elem.in_sg[req->elem.in_num - 1].iov_base;
	285
	286	if (req->out->type & VIRTIO_BLK_T_SCSI_CMD) {
1063b8b1	287	virtio_blk_handle_scsi(req);
6e02c38d	288	} else if (req->out->type & VIRTIO_BLK_T_OUT) {
d28a1b6e AL	289	qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1],
	290	req->elem.out_num - 1);
	291	virtio_blk_handle_write(req);
6e02c38d	292	} else {
d28a1b6e AL	293	qemu_iovec_init_external(&req->qiov, &req->elem.in_sg[0],
	294	req->elem.in_num - 1);
	295	virtio_blk_handle_read(req);
6e02c38d AL	296	}
	297	}
	298	/*
	299	* FIXME: Want to check for completions before returning to guest mode,
	300	* so cached reads and writes are reported as quickly as possible. But
	301	* that should be done in the generic block layer.
	302	*/
	303	}
	304
869a5c6d AL	305	static void virtio_blk_dma_restart_cb(void *opaque, int running, int reason)
	306	{
	307	VirtIOBlock *s = opaque;
	308	VirtIOBlockReq *req = s->rq;
	309
	310	if (!running)
	311	return;
	312
	313	s->rq = NULL;
	314
	315	while (req) {
	316	virtio_blk_handle_write(req);
	317	req = req->next;
	318	}
	319	}
	320
6e02c38d AL	321	static void virtio_blk_reset(VirtIODevice *vdev)
	322	{
	323	/*
	324	* This should cancel pending requests, but can't do nicely until there
	325	* are per-device request lists.
	326	*/
	327	qemu_aio_flush();
	328	}
	329
bf011293	330	/* coalesce internal state, copy to pci i/o region 0
bf011293	331	*/
6e02c38d AL	332	static void virtio_blk_update_config(VirtIODevice vdev, uint8_t config)
	333	{
	334	VirtIOBlock *s = to_virtio_blk(vdev);
	335	struct virtio_blk_config blkcfg;
	336	uint64_t capacity;
	337	int cylinders, heads, secs;
	338
	339	bdrv_get_geometry(s->bs, &capacity);
	340	bdrv_get_geometry_hint(s->bs, &cylinders, &heads, &secs);
5c5dafdc	341	memset(&blkcfg, 0, sizeof(blkcfg));
6e02c38d AL	342	stq_raw(&blkcfg.capacity, capacity);
	343	stl_raw(&blkcfg.seg_max, 128 - 2);
	344	stw_raw(&blkcfg.cylinders, cylinders);
	345	blkcfg.heads = heads;
	346	blkcfg.sectors = secs;
c7085da7	347	blkcfg.size_max = 0;
bf011293	348	virtio_identify_template(&blkcfg);
	349	memcpy(&blkcfg.identify[VIRTIO_BLK_ID_SN], s->serial_str,
	350	VIRTIO_BLK_ID_SN_BYTES);
6e02c38d AL	351	memcpy(config, &blkcfg, sizeof(blkcfg));
	352	}
	353
	354	static uint32_t virtio_blk_get_features(VirtIODevice *vdev)
	355	{
bf011293	356	VirtIOBlock *s = to_virtio_blk(vdev);
1063b8b1 CH	357	uint32_t features = 0;
	358
	359	features \|= (1 << VIRTIO_BLK_F_SEG_MAX);
	360	features \|= (1 << VIRTIO_BLK_F_GEOMETRY);
	361	#ifdef __linux__
	362	features \|= (1 << VIRTIO_BLK_F_SCSI);
	363	#endif
bf011293	364	if (strcmp(s->serial_str, "0"))
bf011293	365	features \|= 1 << VIRTIO_BLK_F_IDENTIFY;
1063b8b1 CH	366
1063b8b1 CH	367	return features;
6e02c38d AL	368	}
	369
	370	static void virtio_blk_save(QEMUFile f, void opaque)
	371	{
	372	VirtIOBlock *s = opaque;
869a5c6d AL	373	VirtIOBlockReq *req = s->rq;
869a5c6d AL	374
6e02c38d	375	virtio_save(&s->vdev, f);
869a5c6d AL	376
	377	while (req) {
	378	qemu_put_sbyte(f, 1);
	379	qemu_put_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem));
	380	req = req->next;
	381	}
	382	qemu_put_sbyte(f, 0);
6e02c38d AL	383	}
	384
	385	static int virtio_blk_load(QEMUFile f, void opaque, int version_id)
	386	{
	387	VirtIOBlock *s = opaque;
	388
869a5c6d	389	if (version_id != 2)
6e02c38d AL	390	return -EINVAL;
	391
	392	virtio_load(&s->vdev, f);
869a5c6d AL	393	while (qemu_get_sbyte(f)) {
	394	VirtIOBlockReq *req = virtio_blk_alloc_request(s);
	395	qemu_get_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem));
	396	req->next = s->rq;
	397	s->rq = req->next;
	398	}
6e02c38d AL	399
	400	return 0;
	401	}
	402
53c25cea	403	VirtIODevice virtio_blk_init(DeviceState dev)
6e02c38d AL	404	{
	405	VirtIOBlock *s;
	406	int cylinders, heads, secs;
	407	static int virtio_blk_id;
07e3af9a	408	BlockDriverState *bs;
bf011293	409	char *ps;
cf21e106	410
53c25cea PB	411	s = (VirtIOBlock *)virtio_common_init("virtio-blk", VIRTIO_ID_BLOCK,
	412	sizeof(struct virtio_blk_config),
	413	sizeof(VirtIOBlock));
6e02c38d	414
53c25cea	415	bs = qdev_init_bdrv(dev, IF_VIRTIO);
6e02c38d AL	416	s->vdev.get_config = virtio_blk_update_config;
	417	s->vdev.get_features = virtio_blk_get_features;
	418	s->vdev.reset = virtio_blk_reset;
	419	s->bs = bs;
869a5c6d	420	s->rq = NULL;
bf011293	421	if (strlen(ps = (char *)drive_get_serial(bs)))
	422	strncpy(s->serial_str, ps, sizeof(s->serial_str));
	423	else
	424	snprintf(s->serial_str, sizeof(s->serial_str), "0");
53c25cea	425	bs->private = dev;
6e02c38d AL	426	bdrv_guess_geometry(s->bs, &cylinders, &heads, &secs);
	427	bdrv_set_geometry_hint(s->bs, cylinders, heads, secs);
	428
	429	s->vq = virtio_add_queue(&s->vdev, 128, virtio_blk_handle_output);
	430
869a5c6d AL	431	qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
869a5c6d AL	432	register_savevm("virtio-blk", virtio_blk_id++, 2,
6e02c38d AL	433	virtio_blk_save, virtio_blk_load, s);
6e02c38d AL	434
53c25cea	435	return &s->vdev;
6e02c38d	436	}