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

/*
 * Virtio Block Device
 *
 * Copyright IBM, Corp. 2007
 *
 * Authors:
 *  Anthony Liguori   <[email protected]>
 *
 * 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;
} VirtIOBlock;

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

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();
}

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);
    stq_raw(&blkcfg.capacity, capacity);
    stl_raw(&blkcfg.seg_max, 128 - 2);
    stw_raw(&blkcfg.cylinders, cylinders);
    blkcfg.heads = heads;
    blkcfg.sectors = secs;
    memcpy(config, &blkcfg, sizeof(blkcfg));
}

static uint32_t virtio_blk_get_features(VirtIODevice *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

    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;
}

void *virtio_blk_init(PCIBus *bus, BlockDriverState *bs)
{
    VirtIOBlock *s;
    int cylinders, heads, secs;
    static int virtio_blk_id;

    s = (VirtIOBlock *)virtio_init_pci(bus, "virtio-blk",
                                       PCI_VENDOR_ID_REDHAT_QUMRANET,
                                       PCI_DEVICE_ID_VIRTIO_BLOCK,
                                       PCI_VENDOR_ID_REDHAT_QUMRANET,
                                       VIRTIO_ID_BLOCK,
                                       PCI_CLASS_STORAGE_OTHER, 0x00,
                                       sizeof(struct virtio_blk_config), sizeof(VirtIOBlock));
    if (!s)
        return NULL;

    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;
    bs->private = &s->vdev.pci_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;
}
Commit	Line	Data
6e02c38d AL	1	/*
	2	* Virtio Block Device
	3	*
	4	* Copyright IBM, Corp. 2007
	5	*
	6	* Authors:
	7	* Anthony Liguori <[email protected]>
	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;
6e02c38d AL	28	} VirtIOBlock;
	29
	30	static VirtIOBlock to_virtio_blk(VirtIODevice vdev)
	31	{
	32	return (VirtIOBlock *)vdev;
	33	}
	34
	35	typedef struct VirtIOBlockReq
	36	{
	37	VirtIOBlock *dev;
	38	VirtQueueElement elem;
	39	struct virtio_blk_inhdr *in;
	40	struct virtio_blk_outhdr *out;
1063b8b1	41	struct virtio_scsi_inhdr *scsi;
d28a1b6e	42	QEMUIOVector qiov;
869a5c6d	43	struct VirtIOBlockReq *next;
6e02c38d AL	44	} VirtIOBlockReq;
6e02c38d AL	45
869a5c6d AL	46	static void virtio_blk_req_complete(VirtIOBlockReq *req, int status)
	47	{
	48	VirtIOBlock *s = req->dev;
	49
	50	req->in->status = status;
d28a1b6e	51	virtqueue_push(s->vq, &req->elem, req->qiov.size + sizeof(*req->in));
869a5c6d AL	52	virtio_notify(&s->vdev, s->vq);
869a5c6d AL	53
869a5c6d AL	54	qemu_free(req);
	55	}
	56
	57	static int virtio_blk_handle_write_error(VirtIOBlockReq *req, int error)
	58	{
	59	BlockInterfaceErrorAction action = drive_get_onerror(req->dev->bs);
	60	VirtIOBlock *s = req->dev;
	61
	62	if (action == BLOCK_ERR_IGNORE)
	63	return 0;
	64
	65	if ((error == ENOSPC && action == BLOCK_ERR_STOP_ENOSPC)
	66	\|\| action == BLOCK_ERR_STOP_ANY) {
	67	req->next = s->rq;
	68	s->rq = req;
	69	vm_stop(0);
	70	} else {
	71	virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
	72	}
	73
	74	return 1;
	75	}
	76
6e02c38d AL	77	static void virtio_blk_rw_complete(void *opaque, int ret)
	78	{
	79	VirtIOBlockReq *req = opaque;
6e02c38d	80
d28a1b6e	81	if (ret && (req->out->type & VIRTIO_BLK_T_OUT)) {
869a5c6d AL	82	if (virtio_blk_handle_write_error(req, -ret))
869a5c6d AL	83	return;
6e02c38d AL	84	}
6e02c38d AL	85
869a5c6d AL	86	virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
869a5c6d AL	87	}
6e02c38d	88
869a5c6d AL	89	static VirtIOBlockReq virtio_blk_alloc_request(VirtIOBlock s)
	90	{
	91	VirtIOBlockReq req = qemu_mallocz(sizeof(req));
487414f1	92	req->dev = s;
869a5c6d	93	return req;
6e02c38d AL	94	}
	95
	96	static VirtIOBlockReq virtio_blk_get_request(VirtIOBlock s)
	97	{
869a5c6d	98	VirtIOBlockReq *req = virtio_blk_alloc_request(s);
6e02c38d	99
869a5c6d AL	100	if (req != NULL) {
	101	if (!virtqueue_pop(s->vq, &req->elem)) {
	102	qemu_free(req);
	103	return NULL;
	104	}
6e02c38d AL	105	}
	106
	107	return req;
	108	}
	109
1063b8b1 CH	110	#ifdef __linux__
	111	static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
	112	{
	113	struct sg_io_hdr hdr;
	114	int ret, size = 0;
	115	int status;
	116	int i;
	117
	118	/*
	119	* We require at least one output segment each for the virtio_blk_outhdr
	120	* and the SCSI command block.
	121	*
	122	* We also at least require the virtio_blk_inhdr, the virtio_scsi_inhdr
	123	* and the sense buffer pointer in the input segments.
	124	*/
	125	if (req->elem.out_num < 2 \|\| req->elem.in_num < 3) {
	126	virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
	127	return;
	128	}
	129
	130	/*
	131	* No support for bidirection commands yet.
	132	*/
	133	if (req->elem.out_num > 2 && req->elem.in_num > 3) {
	134	virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
	135	return;
	136	}
	137
	138	/*
	139	* The scsi inhdr is placed in the second-to-last input segment, just
	140	* before the regular inhdr.
	141	*/
	142	req->scsi = (void *)req->elem.in_sg[req->elem.in_num - 2].iov_base;
	143	size = sizeof(req->in) + sizeof(req->scsi);
	144
	145	memset(&hdr, 0, sizeof(struct sg_io_hdr));
	146	hdr.interface_id = 'S';
	147	hdr.cmd_len = req->elem.out_sg[1].iov_len;
	148	hdr.cmdp = req->elem.out_sg[1].iov_base;
	149	hdr.dxfer_len = 0;
	150
	151	if (req->elem.out_num > 2) {
	152	/*
	153	* If there are more than the minimally required 2 output segments
	154	* there is write payload starting from the third iovec.
	155	*/
	156	hdr.dxfer_direction = SG_DXFER_TO_DEV;
	157	hdr.iovec_count = req->elem.out_num - 2;
	158
	159	for (i = 0; i < hdr.iovec_count; i++)
	160	hdr.dxfer_len += req->elem.out_sg[i + 2].iov_len;
	161
	162	hdr.dxferp = req->elem.out_sg + 2;
	163
	164	} else if (req->elem.in_num > 3) {
	165	/*
	166	* If we have more than 3 input segments the guest wants to actually
	167	* read data.
	168	*/
	169	hdr.dxfer_direction = SG_DXFER_FROM_DEV;
	170	hdr.iovec_count = req->elem.in_num - 3;
	171	for (i = 0; i < hdr.iovec_count; i++)
	172	hdr.dxfer_len += req->elem.in_sg[i].iov_len;
	173
174	hdr.dxferp = req->elem.in_sg;
175	size += hdr.dxfer_len;
176	} else {
177	/*
178	* Some SCSI commands don't actually transfer any data.
179	*/
180	hdr.dxfer_direction = SG_DXFER_NONE;
181	}
182
183	hdr.sbp = req->elem.in_sg[req->elem.in_num - 3].iov_base;
184	hdr.mx_sb_len = req->elem.in_sg[req->elem.in_num - 3].iov_len;
185	size += hdr.mx_sb_len;
186
187	ret = bdrv_ioctl(req->dev->bs, SG_IO, &hdr);
188	if (ret) {
189	status = VIRTIO_BLK_S_UNSUPP;
190	hdr.status = ret;
191	hdr.resid = hdr.dxfer_len;
192	} else if (hdr.status) {
193	status = VIRTIO_BLK_S_IOERR;
194	} else {
195	status = VIRTIO_BLK_S_OK;
196	}
197
198	req->scsi->errors = hdr.status;
199	req->scsi->residual = hdr.resid;
200	req->scsi->sense_len = hdr.sb_len_wr;
201	req->scsi->data_len = hdr.dxfer_len;
202
203	virtio_blk_req_complete(req, status);
204	}
205	#else
206	static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
207	{
208	virtio_blk_req_complete(req, VIRTIO_BLK_S_UNSUPP);
209	}
210	#endif /* __linux__ */
211
d28a1b6e	212	static void virtio_blk_handle_write(VirtIOBlockReq *req)
869a5c6d	213	{
d28a1b6e AL	214	bdrv_aio_writev(req->dev->bs, req->out->sector, &req->qiov,
	215	req->qiov.size / 512, virtio_blk_rw_complete, req);
	216	}
869a5c6d	217
d28a1b6e AL	218	static void virtio_blk_handle_read(VirtIOBlockReq *req)
	219	{
	220	bdrv_aio_readv(req->dev->bs, req->out->sector, &req->qiov,
	221	req->qiov.size / 512, virtio_blk_rw_complete, req);
869a5c6d AL	222	}
869a5c6d AL	223
6e02c38d AL	224	static void virtio_blk_handle_output(VirtIODevice vdev, VirtQueue vq)
	225	{
	226	VirtIOBlock *s = to_virtio_blk(vdev);
	227	VirtIOBlockReq *req;
	228
	229	while ((req = virtio_blk_get_request(s))) {
6e02c38d AL	230	if (req->elem.out_num < 1 \|\| req->elem.in_num < 1) {
	231	fprintf(stderr, "virtio-blk missing headers\n");
	232	exit(1);
	233	}
	234
	235	if (req->elem.out_sg[0].iov_len < sizeof(*req->out) \|\|
	236	req->elem.in_sg[req->elem.in_num - 1].iov_len < sizeof(*req->in)) {
	237	fprintf(stderr, "virtio-blk header not in correct element\n");
	238	exit(1);
	239	}
	240
	241	req->out = (void *)req->elem.out_sg[0].iov_base;
	242	req->in = (void *)req->elem.in_sg[req->elem.in_num - 1].iov_base;
	243
	244	if (req->out->type & VIRTIO_BLK_T_SCSI_CMD) {
1063b8b1	245	virtio_blk_handle_scsi(req);
6e02c38d	246	} else if (req->out->type & VIRTIO_BLK_T_OUT) {
d28a1b6e AL	247	qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1],
	248	req->elem.out_num - 1);
	249	virtio_blk_handle_write(req);
6e02c38d	250	} else {
d28a1b6e AL	251	qemu_iovec_init_external(&req->qiov, &req->elem.in_sg[0],
	252	req->elem.in_num - 1);
	253	virtio_blk_handle_read(req);
6e02c38d AL	254	}
	255	}
	256	/*
	257	* FIXME: Want to check for completions before returning to guest mode,
	258	* so cached reads and writes are reported as quickly as possible. But
	259	* that should be done in the generic block layer.
	260	*/
	261	}
	262
869a5c6d AL	263	static void virtio_blk_dma_restart_cb(void *opaque, int running, int reason)
	264	{
	265	VirtIOBlock *s = opaque;
	266	VirtIOBlockReq *req = s->rq;
	267
	268	if (!running)
	269	return;
	270
	271	s->rq = NULL;
	272
	273	while (req) {
	274	virtio_blk_handle_write(req);
	275	req = req->next;
	276	}
	277	}
	278
6e02c38d AL	279	static void virtio_blk_reset(VirtIODevice *vdev)
	280	{
	281	/*
	282	* This should cancel pending requests, but can't do nicely until there
	283	* are per-device request lists.
	284	*/
	285	qemu_aio_flush();
	286	}
	287
	288	static void virtio_blk_update_config(VirtIODevice vdev, uint8_t config)
	289	{
	290	VirtIOBlock *s = to_virtio_blk(vdev);
	291	struct virtio_blk_config blkcfg;
	292	uint64_t capacity;
	293	int cylinders, heads, secs;
	294
	295	bdrv_get_geometry(s->bs, &capacity);
	296	bdrv_get_geometry_hint(s->bs, &cylinders, &heads, &secs);
	297	stq_raw(&blkcfg.capacity, capacity);
	298	stl_raw(&blkcfg.seg_max, 128 - 2);
	299	stw_raw(&blkcfg.cylinders, cylinders);
	300	blkcfg.heads = heads;
	301	blkcfg.sectors = secs;
	302	memcpy(config, &blkcfg, sizeof(blkcfg));
	303	}
	304
	305	static uint32_t virtio_blk_get_features(VirtIODevice *vdev)
	306	{
1063b8b1 CH	307	uint32_t features = 0;
	308
	309	features \|= (1 << VIRTIO_BLK_F_SEG_MAX);
	310	features \|= (1 << VIRTIO_BLK_F_GEOMETRY);
	311	#ifdef __linux__
	312	features \|= (1 << VIRTIO_BLK_F_SCSI);
	313	#endif
	314
	315	return features;
6e02c38d AL	316	}
	317
	318	static void virtio_blk_save(QEMUFile f, void opaque)
	319	{
	320	VirtIOBlock *s = opaque;
869a5c6d AL	321	VirtIOBlockReq *req = s->rq;
869a5c6d AL	322
6e02c38d	323	virtio_save(&s->vdev, f);
869a5c6d AL	324
	325	while (req) {
	326	qemu_put_sbyte(f, 1);
	327	qemu_put_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem));
	328	req = req->next;
	329	}
	330	qemu_put_sbyte(f, 0);
6e02c38d AL	331	}
	332
	333	static int virtio_blk_load(QEMUFile f, void opaque, int version_id)
	334	{
	335	VirtIOBlock *s = opaque;
	336
869a5c6d	337	if (version_id != 2)
6e02c38d AL	338	return -EINVAL;
	339
	340	virtio_load(&s->vdev, f);
869a5c6d AL	341	while (qemu_get_sbyte(f)) {
	342	VirtIOBlockReq *req = virtio_blk_alloc_request(s);
	343	qemu_get_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem));
	344	req->next = s->rq;
	345	s->rq = req->next;
	346	}
6e02c38d AL	347
	348	return 0;
	349	}
	350
9b32d5a5	351	void virtio_blk_init(PCIBus bus, BlockDriverState *bs)
6e02c38d AL	352	{
	353	VirtIOBlock *s;
	354	int cylinders, heads, secs;
	355	static int virtio_blk_id;
	356
9b32d5a5 AL	357	s = (VirtIOBlock *)virtio_init_pci(bus, "virtio-blk",
	358	PCI_VENDOR_ID_REDHAT_QUMRANET,
	359	PCI_DEVICE_ID_VIRTIO_BLOCK,
99b3718e AL	360	PCI_VENDOR_ID_REDHAT_QUMRANET,
99b3718e AL	361	VIRTIO_ID_BLOCK,
173a543b	362	PCI_CLASS_STORAGE_OTHER, 0x00,
6e02c38d AL	363	sizeof(struct virtio_blk_config), sizeof(VirtIOBlock));
	364	if (!s)
	365	return NULL;
	366
	367	s->vdev.get_config = virtio_blk_update_config;
	368	s->vdev.get_features = virtio_blk_get_features;
	369	s->vdev.reset = virtio_blk_reset;
	370	s->bs = bs;
869a5c6d	371	s->rq = NULL;
b0a7b120	372	bs->private = &s->vdev.pci_dev;
6e02c38d AL	373	bdrv_guess_geometry(s->bs, &cylinders, &heads, &secs);
	374	bdrv_set_geometry_hint(s->bs, cylinders, heads, secs);
	375
	376	s->vq = virtio_add_queue(&s->vdev, 128, virtio_blk_handle_output);
	377
869a5c6d AL	378	qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
869a5c6d AL	379	register_savevm("virtio-blk", virtio_blk_id++, 2,
6e02c38d AL	380	virtio_blk_save, virtio_blk_load, s);
	381
	382	return s;
	383	}