Revision d28a1b6e hw/virtio-blk.c
| b/hw/virtio-blk.c | ||
|---|---|---|
| 35 | 35 |
VirtQueueElement elem; |
| 36 | 36 |
struct virtio_blk_inhdr *in; |
| 37 | 37 |
struct virtio_blk_outhdr *out; |
| 38 |
size_t size; |
|
| 39 |
uint8_t *buffer; |
|
| 38 |
QEMUIOVector qiov; |
|
| 40 | 39 |
struct VirtIOBlockReq *next; |
| 41 | 40 |
} VirtIOBlockReq; |
| 42 | 41 |
|
| ... | ... | |
| 45 | 44 |
VirtIOBlock *s = req->dev; |
| 46 | 45 |
|
| 47 | 46 |
req->in->status = status; |
| 48 |
virtqueue_push(s->vq, &req->elem, req->size + sizeof(*req->in)); |
|
| 47 |
virtqueue_push(s->vq, &req->elem, req->qiov.size + sizeof(*req->in));
|
|
| 49 | 48 |
virtio_notify(&s->vdev, s->vq); |
| 50 | 49 |
|
| 51 |
qemu_free(req->buffer); |
|
| 52 | 50 |
qemu_free(req); |
| 53 | 51 |
} |
| 54 | 52 |
|
| ... | ... | |
| 76 | 74 |
{
|
| 77 | 75 |
VirtIOBlockReq *req = opaque; |
| 78 | 76 |
|
| 79 |
/* Copy read data to the guest */ |
|
| 80 |
if (!ret && !(req->out->type & VIRTIO_BLK_T_OUT)) {
|
|
| 81 |
size_t offset = 0; |
|
| 82 |
int i; |
|
| 83 |
|
|
| 84 |
for (i = 0; i < req->elem.in_num - 1; i++) {
|
|
| 85 |
size_t len; |
|
| 86 |
|
|
| 87 |
/* Be pretty defensive wrt malicious guests */ |
|
| 88 |
len = MIN(req->elem.in_sg[i].iov_len, |
|
| 89 |
req->size - offset); |
|
| 90 |
|
|
| 91 |
memcpy(req->elem.in_sg[i].iov_base, |
|
| 92 |
req->buffer + offset, |
|
| 93 |
len); |
|
| 94 |
offset += len; |
|
| 95 |
} |
|
| 96 |
} else if (ret && (req->out->type & VIRTIO_BLK_T_OUT)) {
|
|
| 77 |
if (ret && (req->out->type & VIRTIO_BLK_T_OUT)) {
|
|
| 97 | 78 |
if (virtio_blk_handle_write_error(req, -ret)) |
| 98 | 79 |
return; |
| 99 | 80 |
} |
| ... | ... | |
| 122 | 103 |
return req; |
| 123 | 104 |
} |
| 124 | 105 |
|
| 125 |
static int virtio_blk_handle_write(VirtIOBlockReq *req)
|
|
| 106 |
static void virtio_blk_handle_write(VirtIOBlockReq *req)
|
|
| 126 | 107 |
{
|
| 127 |
if (!req->buffer) {
|
|
| 128 |
size_t offset = 0; |
|
| 129 |
int i; |
|
| 130 |
|
|
| 131 |
for (i = 1; i < req->elem.out_num; i++) |
|
| 132 |
req->size += req->elem.out_sg[i].iov_len; |
|
| 133 |
|
|
| 134 |
req->buffer = qemu_memalign(512, req->size); |
|
| 135 |
if (req->buffer == NULL) {
|
|
| 136 |
qemu_free(req); |
|
| 137 |
return -1; |
|
| 138 |
} |
|
| 139 |
|
|
| 140 |
/* We copy the data from the SG list to avoid splitting up the request. |
|
| 141 |
This helps performance a lot until we can pass full sg lists as AIO |
|
| 142 |
operations */ |
|
| 143 |
for (i = 1; i < req->elem.out_num; i++) {
|
|
| 144 |
size_t len; |
|
| 145 |
|
|
| 146 |
len = MIN(req->elem.out_sg[i].iov_len, |
|
| 147 |
req->size - offset); |
|
| 148 |
memcpy(req->buffer + offset, |
|
| 149 |
req->elem.out_sg[i].iov_base, |
|
| 150 |
len); |
|
| 151 |
offset += len; |
|
| 152 |
} |
|
| 153 |
} |
|
| 108 |
bdrv_aio_writev(req->dev->bs, req->out->sector, &req->qiov, |
|
| 109 |
req->qiov.size / 512, virtio_blk_rw_complete, req); |
|
| 110 |
} |
|
| 154 | 111 |
|
| 155 |
bdrv_aio_write(req->dev->bs, req->out->sector, req->buffer, req->size / 512, |
|
| 156 |
virtio_blk_rw_complete, req); |
|
| 157 |
return 0; |
|
| 112 |
static void virtio_blk_handle_read(VirtIOBlockReq *req) |
|
| 113 |
{
|
|
| 114 |
bdrv_aio_readv(req->dev->bs, req->out->sector, &req->qiov, |
|
| 115 |
req->qiov.size / 512, virtio_blk_rw_complete, req); |
|
| 158 | 116 |
} |
| 159 | 117 |
|
| 160 | 118 |
static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) |
| ... | ... | |
| 163 | 121 |
VirtIOBlockReq *req; |
| 164 | 122 |
|
| 165 | 123 |
while ((req = virtio_blk_get_request(s))) {
|
| 166 |
int i; |
|
| 167 |
|
|
| 168 | 124 |
if (req->elem.out_num < 1 || req->elem.in_num < 1) {
|
| 169 | 125 |
fprintf(stderr, "virtio-blk missing headers\n"); |
| 170 | 126 |
exit(1); |
| ... | ... | |
| 187 | 143 |
virtio_notify(vdev, vq); |
| 188 | 144 |
qemu_free(req); |
| 189 | 145 |
} else if (req->out->type & VIRTIO_BLK_T_OUT) {
|
| 190 |
if (virtio_blk_handle_write(req) < 0) |
|
| 191 |
break; |
|
| 146 |
qemu_iovec_init_external(&req->qiov, &req->elem.out_sg[1], |
|
| 147 |
req->elem.out_num - 1); |
|
| 148 |
virtio_blk_handle_write(req); |
|
| 192 | 149 |
} else {
|
| 193 |
for (i = 0; i < req->elem.in_num - 1; i++) |
|
| 194 |
req->size += req->elem.in_sg[i].iov_len; |
|
| 195 |
|
|
| 196 |
req->buffer = qemu_memalign(512, req->size); |
|
| 197 |
if (req->buffer == NULL) {
|
|
| 198 |
qemu_free(req); |
|
| 199 |
break; |
|
| 200 |
} |
|
| 201 |
|
|
| 202 |
bdrv_aio_read(s->bs, req->out->sector, |
|
| 203 |
req->buffer, |
|
| 204 |
req->size / 512, |
|
| 205 |
virtio_blk_rw_complete, |
|
| 206 |
req); |
|
| 150 |
qemu_iovec_init_external(&req->qiov, &req->elem.in_sg[0], |
|
| 151 |
req->elem.in_num - 1); |
|
| 152 |
virtio_blk_handle_read(req); |
|
| 207 | 153 |
} |
| 208 | 154 |
} |
| 209 | 155 |
/* |
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