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qemu-e2k/hw/virtio-blk.c
Bruce Rogers 3cc128bb1e Remove un-needed code 
The bdrv_set_geometry_hint call below is not needed - it's just setting
what was just read.

Signed-off-by: Bruce Rogers <brogers@novell.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-04-23 16:21:57 +02:00

506 lines
13 KiB
C
Raw Blame History

/*
* 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;
QEMUBH *bh;
BlockConf *conf;
unsigned short sector_mask;
} 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_rw_error(VirtIOBlockReq *req, int error,
int is_read)
{
BlockInterfaceErrorAction action =
drive_get_on_error(req->dev->bs, is_read);
VirtIOBlock *s = req->dev;
if (action == BLOCK_ERR_IGNORE) {
bdrv_mon_event(s->bs, BDRV_ACTION_IGNORE, is_read);
return 0;
}
if ((error == ENOSPC && action == BLOCK_ERR_STOP_ENOSPC)
|| action == BLOCK_ERR_STOP_ANY) {
req->next = s->rq;
s->rq = req;
bdrv_mon_event(s->bs, BDRV_ACTION_STOP, is_read);
vm_stop(0);
} else {
virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
bdrv_mon_event(s->bs, BDRV_ACTION_REPORT, is_read);
}
return 1;
}
static void virtio_blk_rw_complete(void *opaque, int ret)
{
VirtIOBlockReq *req = opaque;
if (ret) {
int is_read = !(req->out->type & VIRTIO_BLK_T_OUT);
if (virtio_blk_handle_rw_error(req, -ret, is_read))
return;
}
virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
}
static void virtio_blk_flush_complete(void *opaque, int ret)
{
VirtIOBlockReq *req = opaque;
virtio_blk_req_complete(req, ret ? VIRTIO_BLK_S_IOERR : 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;
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;
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;
} 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;
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 do_multiwrite(BlockDriverState *bs, BlockRequest *blkreq,
int num_writes)
{
int i, ret;
ret = bdrv_aio_multiwrite(bs, blkreq, num_writes);
if (ret != 0) {
for (i = 0; i < num_writes; i++) {
if (blkreq[i].error) {
virtio_blk_rw_complete(blkreq[i].opaque, -EIO);
}
}
}
}
static void virtio_blk_handle_flush(VirtIOBlockReq *req)
{
BlockDriverAIOCB *acb;
acb = bdrv_aio_flush(req->dev->bs, virtio_blk_flush_complete, req);
if (!acb) {
virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
}
}
static void virtio_blk_handle_write(BlockRequest *blkreq, int *num_writes,
VirtIOBlockReq *req, BlockDriverState **old_bs)
{
if (req->out->sector & req->dev->sector_mask) {
virtio_blk_rw_complete(req, -EIO);
return;
}
if (req->dev->bs != *old_bs || *num_writes == 32) {
if (*old_bs != NULL) {
do_multiwrite(*old_bs, blkreq, *num_writes);
}
*num_writes = 0;
*old_bs = req->dev->bs;
}
blkreq[*num_writes].sector = req->out->sector;
blkreq[*num_writes].nb_sectors = req->qiov.size / 512;
blkreq[*num_writes].qiov = &req->qiov;
blkreq[*num_writes].cb = virtio_blk_rw_complete;
blkreq[*num_writes].opaque = req;
blkreq[*num_writes].error = 0;
(*num_writes)++;
}
static void virtio_blk_handle_read(VirtIOBlockReq *req)
{
BlockDriverAIOCB *acb;
if (req->out->sector & req->dev->sector_mask) {
virtio_blk_rw_complete(req, -EIO);
return;
}
acb = bdrv_aio_readv(req->dev->bs, req->out->sector, &req->qiov,
req->qiov.size / 512, virtio_blk_rw_complete, req);
if (!acb) {
virtio_blk_rw_complete(req, -EIO);
}
}
typedef struct MultiReqBuffer {
BlockRequest blkreq[32];
int num_writes;
BlockDriverState *old_bs;
} MultiReqBuffer;
static void virtio_blk_handle_request(VirtIOBlockReq *req,
MultiReqBuffer *mrb)
{
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_FLUSH) {
virtio_blk_handle_flush(req);
} else 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(mrb->blkreq, &mrb->num_writes,
req, &mrb->old_bs);
} else {
qemu_iovec_init_external(&req->qiov, &req->elem.in_sg[0],
req->elem.in_num - 1);
virtio_blk_handle_read(req);
}
}
static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIOBlock *s = to_virtio_blk(vdev);
VirtIOBlockReq *req;
MultiReqBuffer mrb = {
.num_writes = 0,
.old_bs = NULL,
};
while ((req = virtio_blk_get_request(s))) {
virtio_blk_handle_request(req, &mrb);
}
if (mrb.num_writes > 0) {
do_multiwrite(mrb.old_bs, mrb.blkreq, mrb.num_writes);
}
/*
* 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_bh(void *opaque)
{
VirtIOBlock *s = opaque;
VirtIOBlockReq *req = s->rq;
MultiReqBuffer mrb = {
.num_writes = 0,
.old_bs = NULL,
};
qemu_bh_delete(s->bh);
s->bh = NULL;
s->rq = NULL;
while (req) {
virtio_blk_handle_request(req, &mrb);
req = req->next;
}
if (mrb.num_writes > 0) {
do_multiwrite(mrb.old_bs, mrb.blkreq, mrb.num_writes);
}
}
static void virtio_blk_dma_restart_cb(void *opaque, int running, int reason)
{
VirtIOBlock *s = opaque;
if (!running)
return;
if (!s->bh) {
s->bh = qemu_bh_new(virtio_blk_dma_restart_bh, s);
qemu_bh_schedule(s->bh);
}
}
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 & ~s->sector_mask;
blkcfg.blk_size = s->conf->logical_block_size;
blkcfg.size_max = 0;
blkcfg.physical_block_exp = get_physical_block_exp(s->conf);
blkcfg.alignment_offset = 0;
blkcfg.min_io_size = s->conf->min_io_size / blkcfg.blk_size;
blkcfg.opt_io_size = s->conf->opt_io_size / blkcfg.blk_size;
memcpy(config, &blkcfg, sizeof(struct virtio_blk_config));
}
static uint32_t virtio_blk_get_features(VirtIODevice *vdev, uint32_t features)
{
VirtIOBlock *s = to_virtio_blk(vdev);
features |= (1 << VIRTIO_BLK_F_SEG_MAX);
features |= (1 << VIRTIO_BLK_F_GEOMETRY);
features |= (1 << VIRTIO_BLK_F_TOPOLOGY);
features |= (1 << VIRTIO_BLK_F_BLK_SIZE);
if (bdrv_enable_write_cache(s->bs))
features |= (1 << VIRTIO_BLK_F_WCACHE);
if (bdrv_is_read_only(s->bs))
features |= 1 << VIRTIO_BLK_F_RO;
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, BlockConf *conf)
{
VirtIOBlock *s;
int cylinders, heads, secs;
static int virtio_blk_id;
s = (VirtIOBlock *)virtio_common_init("virtio-blk", VIRTIO_ID_BLOCK,
sizeof(struct virtio_blk_config),
sizeof(VirtIOBlock));
s->vdev.get_config = virtio_blk_update_config;
s->vdev.get_features = virtio_blk_get_features;
s->vdev.reset = virtio_blk_reset;
s->bs = conf->dinfo->bdrv;
s->conf = conf;
s->rq = NULL;
s->sector_mask = (s->conf->logical_block_size / 512) - 1;
bdrv_guess_geometry(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;
}
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