Revision 869a5c6d hw/virtio-blk.c
| b/hw/virtio-blk.c | ||
|---|---|---|
| 11 | 11 |
* |
| 12 | 12 |
*/ |
| 13 | 13 |
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#include <qemu-common.h> |
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#include <sysemu.h> |
|
| 14 | 16 |
#include "virtio-blk.h" |
| 15 | 17 |
#include "block_int.h" |
| 16 | 18 |
|
| ... | ... | |
| 19 | 21 |
VirtIODevice vdev; |
| 20 | 22 |
BlockDriverState *bs; |
| 21 | 23 |
VirtQueue *vq; |
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void *rq; |
|
| 22 | 25 |
} VirtIOBlock; |
| 23 | 26 |
|
| 24 | 27 |
static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev) |
| ... | ... | |
| 34 | 37 |
struct virtio_blk_outhdr *out; |
| 35 | 38 |
size_t size; |
| 36 | 39 |
uint8_t *buffer; |
| 40 |
struct VirtIOBlockReq *next; |
|
| 37 | 41 |
} VirtIOBlockReq; |
| 38 | 42 |
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static void virtio_blk_req_complete(VirtIOBlockReq *req, int status) |
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{
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VirtIOBlock *s = req->dev; |
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|
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req->in->status = status; |
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virtqueue_push(s->vq, &req->elem, req->size + sizeof(*req->in)); |
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virtio_notify(&s->vdev, s->vq); |
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|
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qemu_free(req->buffer); |
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qemu_free(req); |
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} |
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|
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static int virtio_blk_handle_write_error(VirtIOBlockReq *req, int error) |
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{
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BlockInterfaceErrorAction action = drive_get_onerror(req->dev->bs); |
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VirtIOBlock *s = req->dev; |
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|
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if (action == BLOCK_ERR_IGNORE) |
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return 0; |
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|
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if ((error == ENOSPC && action == BLOCK_ERR_STOP_ENOSPC) |
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|| action == BLOCK_ERR_STOP_ANY) {
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req->next = s->rq; |
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s->rq = req; |
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vm_stop(0); |
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} else {
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virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); |
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} |
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return 1; |
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} |
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|
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static void virtio_blk_rw_complete(void *opaque, int ret) |
| 40 | 76 |
{
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VirtIOBlockReq *req = opaque; |
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VirtIOBlock *s = req->dev; |
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/* Copy read data to the guest */ |
| 45 | 80 |
if (!ret && !(req->out->type & VIRTIO_BLK_T_OUT)) {
|
| ... | ... | |
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len); |
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offset += len; |
| 60 | 95 |
} |
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} else if (ret && (req->out->type & VIRTIO_BLK_T_OUT)) {
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if (virtio_blk_handle_write_error(req, -ret)) |
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return; |
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} |
| 62 | 100 |
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req->in->status = ret ? VIRTIO_BLK_S_IOERR : VIRTIO_BLK_S_OK; |
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virtqueue_push(s->vq, &req->elem, req->size + sizeof(*req->in)); |
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virtio_notify(&s->vdev, s->vq); |
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virtio_blk_req_complete(req, VIRTIO_BLK_S_OK); |
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} |
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qemu_free(req->buffer); |
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qemu_free(req); |
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static VirtIOBlockReq *virtio_blk_alloc_request(VirtIOBlock *s) |
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{
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VirtIOBlockReq *req = qemu_mallocz(sizeof(*req)); |
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if (req != NULL) |
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req->dev = s; |
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return req; |
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} |
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static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s) |
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{
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VirtIOBlockReq *req; |
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VirtIOBlockReq *req = virtio_blk_alloc_request(s);
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req = qemu_mallocz(sizeof(*req)); |
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if (req == NULL) |
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return NULL; |
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req->dev = s; |
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if (!virtqueue_pop(s->vq, &req->elem)) {
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qemu_free(req); |
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return NULL; |
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if (req != NULL) {
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if (!virtqueue_pop(s->vq, &req->elem)) {
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qemu_free(req); |
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return NULL; |
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} |
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} |
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return req; |
| 86 | 124 |
} |
| 87 | 125 |
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static int virtio_blk_handle_write(VirtIOBlockReq *req) |
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{
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if (!req->buffer) {
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size_t offset = 0; |
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int i; |
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for (i = 1; i < req->elem.out_num; i++) |
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req->size += req->elem.out_sg[i].iov_len; |
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req->buffer = qemu_memalign(512, req->size); |
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if (req->buffer == NULL) {
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qemu_free(req); |
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return -1; |
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} |
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|
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/* We copy the data from the SG list to avoid splitting up the request. |
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This helps performance a lot until we can pass full sg lists as AIO |
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operations */ |
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for (i = 1; i < req->elem.out_num; i++) {
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size_t len; |
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len = MIN(req->elem.out_sg[i].iov_len, |
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req->size - offset); |
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memcpy(req->buffer + offset, |
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req->elem.out_sg[i].iov_base, |
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len); |
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offset += len; |
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} |
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} |
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|
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bdrv_aio_write(req->dev->bs, req->out->sector, req->buffer, req->size / 512, |
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virtio_blk_rw_complete, req); |
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return 0; |
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} |
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|
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static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) |
| 89 | 162 |
{
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VirtIOBlock *s = to_virtio_blk(vdev); |
| ... | ... | |
| 115 | 188 |
virtio_notify(vdev, vq); |
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qemu_free(req); |
| 117 | 190 |
} else if (req->out->type & VIRTIO_BLK_T_OUT) {
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size_t offset; |
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|
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for (i = 1; i < req->elem.out_num; i++) |
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req->size += req->elem.out_sg[i].iov_len; |
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|
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req->buffer = qemu_memalign(512, req->size); |
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if (req->buffer == NULL) {
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qemu_free(req); |
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if (virtio_blk_handle_write(req) < 0) |
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break; |
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} |
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|
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/* We copy the data from the SG list to avoid splitting up the request. This helps |
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performance a lot until we can pass full sg lists as AIO operations */ |
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offset = 0; |
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for (i = 1; i < req->elem.out_num; i++) {
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size_t len; |
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|
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len = MIN(req->elem.out_sg[i].iov_len, |
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req->size - offset); |
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memcpy(req->buffer + offset, |
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req->elem.out_sg[i].iov_base, |
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len); |
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offset += len; |
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} |
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|
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bdrv_aio_write(s->bs, req->out->sector, |
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req->buffer, |
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req->size / 512, |
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virtio_blk_rw_complete, |
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req); |
|
| 148 | 193 |
} else {
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for (i = 0; i < req->elem.in_num - 1; i++) |
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req->size += req->elem.in_sg[i].iov_len; |
| ... | ... | |
| 169 | 214 |
*/ |
| 170 | 215 |
} |
| 171 | 216 |
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static void virtio_blk_dma_restart_cb(void *opaque, int running, int reason) |
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{
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VirtIOBlock *s = opaque; |
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VirtIOBlockReq *req = s->rq; |
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|
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if (!running) |
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return; |
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|
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s->rq = NULL; |
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|
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while (req) {
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virtio_blk_handle_write(req); |
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req = req->next; |
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} |
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} |
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|
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static void virtio_blk_reset(VirtIODevice *vdev) |
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{
|
| 174 | 235 |
/* |
| ... | ... | |
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static void virtio_blk_save(QEMUFile *f, void *opaque) |
| 204 | 265 |
{
|
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VirtIOBlock *s = opaque; |
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VirtIOBlockReq *req = s->rq; |
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|
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virtio_save(&s->vdev, f); |
| 270 |
|
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while (req) {
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qemu_put_sbyte(f, 1); |
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qemu_put_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem)); |
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req = req->next; |
|
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} |
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qemu_put_sbyte(f, 0); |
|
| 207 | 277 |
} |
| 208 | 278 |
|
| 209 | 279 |
static int virtio_blk_load(QEMUFile *f, void *opaque, int version_id) |
| 210 | 280 |
{
|
| 211 | 281 |
VirtIOBlock *s = opaque; |
| 212 | 282 |
|
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if (version_id != 1)
|
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if (version_id != 2)
|
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return -EINVAL; |
| 215 | 285 |
|
| 216 | 286 |
virtio_load(&s->vdev, f); |
| 287 |
while (qemu_get_sbyte(f)) {
|
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VirtIOBlockReq *req = virtio_blk_alloc_request(s); |
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qemu_get_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem)); |
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req->next = s->rq; |
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s->rq = req->next; |
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} |
|
| 217 | 293 |
|
| 218 | 294 |
return 0; |
| 219 | 295 |
} |
| ... | ... | |
| 237 | 313 |
s->vdev.get_features = virtio_blk_get_features; |
| 238 | 314 |
s->vdev.reset = virtio_blk_reset; |
| 239 | 315 |
s->bs = bs; |
| 316 |
s->rq = NULL; |
|
| 240 | 317 |
bdrv_guess_geometry(s->bs, &cylinders, &heads, &secs); |
| 241 | 318 |
bdrv_set_geometry_hint(s->bs, cylinders, heads, secs); |
| 242 | 319 |
|
| 243 | 320 |
s->vq = virtio_add_queue(&s->vdev, 128, virtio_blk_handle_output); |
| 244 | 321 |
|
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register_savevm("virtio-blk", virtio_blk_id++, 1,
|
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qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s); |
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register_savevm("virtio-blk", virtio_blk_id++, 2,
|
|
| 246 | 324 |
virtio_blk_save, virtio_blk_load, s); |
| 247 | 325 |
|
| 248 | 326 |
return s; |
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