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14#include <qemu-common.h>
15#include <sysemu.h>
16#include "virtio-blk.h"
17#include "block_int.h"
18
19typedef struct VirtIOBlock
20{
21 VirtIODevice vdev;
22 BlockDriverState *bs;
23 VirtQueue *vq;
24 void *rq;
25} VirtIOBlock;
26
27static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev)
28{
29 return (VirtIOBlock *)vdev;
30}
31
32typedef struct VirtIOBlockReq
33{
34 VirtIOBlock *dev;
35 VirtQueueElement elem;
36 struct virtio_blk_inhdr *in;
37 struct virtio_blk_outhdr *out;
38 size_t size;
39 uint8_t *buffer;
40 struct VirtIOBlockReq *next;
41} VirtIOBlockReq;
42
43static void virtio_blk_req_complete(VirtIOBlockReq *req, int status)
44{
45 VirtIOBlock *s = req->dev;
46
47 req->in->status = status;
48 virtqueue_push(s->vq, &req->elem, req->size + sizeof(*req->in));
49 virtio_notify(&s->vdev, s->vq);
50
51 qemu_free(req->buffer);
52 qemu_free(req);
53}
54
55static int virtio_blk_handle_write_error(VirtIOBlockReq *req, int error)
56{
57 BlockInterfaceErrorAction action = drive_get_onerror(req->dev->bs);
58 VirtIOBlock *s = req->dev;
59
60 if (action == BLOCK_ERR_IGNORE)
61 return 0;
62
63 if ((error == ENOSPC && action == BLOCK_ERR_STOP_ENOSPC)
64 || action == BLOCK_ERR_STOP_ANY) {
65 req->next = s->rq;
66 s->rq = req;
67 vm_stop(0);
68 } else {
69 virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR);
70 }
71
72 return 1;
73}
74
75static void virtio_blk_rw_complete(void *opaque, int ret)
76{
77 VirtIOBlockReq *req = opaque;
78
79
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
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)) {
97 if (virtio_blk_handle_write_error(req, -ret))
98 return;
99 }
100
101 virtio_blk_req_complete(req, VIRTIO_BLK_S_OK);
102}
103
104static VirtIOBlockReq *virtio_blk_alloc_request(VirtIOBlock *s)
105{
106 VirtIOBlockReq *req = qemu_mallocz(sizeof(*req));
107 req->dev = s;
108 return req;
109}
110
111static VirtIOBlockReq *virtio_blk_get_request(VirtIOBlock *s)
112{
113 VirtIOBlockReq *req = virtio_blk_alloc_request(s);
114
115 if (req != NULL) {
116 if (!virtqueue_pop(s->vq, &req->elem)) {
117 qemu_free(req);
118 return NULL;
119 }
120 }
121
122 return req;
123}
124
125static int virtio_blk_handle_write(VirtIOBlockReq *req)
126{
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
141
142
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 }
154
155 bdrv_aio_write(req->dev->bs, req->out->sector, req->buffer, req->size / 512,
156 virtio_blk_rw_complete, req);
157 return 0;
158}
159
160static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
161{
162 VirtIOBlock *s = to_virtio_blk(vdev);
163 VirtIOBlockReq *req;
164
165 while ((req = virtio_blk_get_request(s))) {
166 int i;
167
168 if (req->elem.out_num < 1 || req->elem.in_num < 1) {
169 fprintf(stderr, "virtio-blk missing headers\n");
170 exit(1);
171 }
172
173 if (req->elem.out_sg[0].iov_len < sizeof(*req->out) ||
174 req->elem.in_sg[req->elem.in_num - 1].iov_len < sizeof(*req->in)) {
175 fprintf(stderr, "virtio-blk header not in correct element\n");
176 exit(1);
177 }
178
179 req->out = (void *)req->elem.out_sg[0].iov_base;
180 req->in = (void *)req->elem.in_sg[req->elem.in_num - 1].iov_base;
181
182 if (req->out->type & VIRTIO_BLK_T_SCSI_CMD) {
183 unsigned int len = sizeof(*req->in);
184
185 req->in->status = VIRTIO_BLK_S_UNSUPP;
186 virtqueue_push(vq, &req->elem, len);
187 virtio_notify(vdev, vq);
188 qemu_free(req);
189 } else if (req->out->type & VIRTIO_BLK_T_OUT) {
190 if (virtio_blk_handle_write(req) < 0)
191 break;
192 } 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);
207 }
208 }
209
210
211
212
213
214}
215
216static void virtio_blk_dma_restart_cb(void *opaque, int running, int reason)
217{
218 VirtIOBlock *s = opaque;
219 VirtIOBlockReq *req = s->rq;
220
221 if (!running)
222 return;
223
224 s->rq = NULL;
225
226 while (req) {
227 virtio_blk_handle_write(req);
228 req = req->next;
229 }
230}
231
232static void virtio_blk_reset(VirtIODevice *vdev)
233{
234
235
236
237
238 qemu_aio_flush();
239}
240
241static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config)
242{
243 VirtIOBlock *s = to_virtio_blk(vdev);
244 struct virtio_blk_config blkcfg;
245 uint64_t capacity;
246 int cylinders, heads, secs;
247
248 bdrv_get_geometry(s->bs, &capacity);
249 bdrv_get_geometry_hint(s->bs, &cylinders, &heads, &secs);
250 stq_raw(&blkcfg.capacity, capacity);
251 stl_raw(&blkcfg.seg_max, 128 - 2);
252 stw_raw(&blkcfg.cylinders, cylinders);
253 blkcfg.heads = heads;
254 blkcfg.sectors = secs;
255 memcpy(config, &blkcfg, sizeof(blkcfg));
256}
257
258static uint32_t virtio_blk_get_features(VirtIODevice *vdev)
259{
260 return (1 << VIRTIO_BLK_F_SEG_MAX | 1 << VIRTIO_BLK_F_GEOMETRY);
261}
262
263static void virtio_blk_save(QEMUFile *f, void *opaque)
264{
265 VirtIOBlock *s = opaque;
266 VirtIOBlockReq *req = s->rq;
267
268 virtio_save(&s->vdev, f);
269
270 while (req) {
271 qemu_put_sbyte(f, 1);
272 qemu_put_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem));
273 req = req->next;
274 }
275 qemu_put_sbyte(f, 0);
276}
277
278static int virtio_blk_load(QEMUFile *f, void *opaque, int version_id)
279{
280 VirtIOBlock *s = opaque;
281
282 if (version_id != 2)
283 return -EINVAL;
284
285 virtio_load(&s->vdev, f);
286 while (qemu_get_sbyte(f)) {
287 VirtIOBlockReq *req = virtio_blk_alloc_request(s);
288 qemu_get_buffer(f, (unsigned char*)&req->elem, sizeof(req->elem));
289 req->next = s->rq;
290 s->rq = req->next;
291 }
292
293 return 0;
294}
295
296void *virtio_blk_init(PCIBus *bus, BlockDriverState *bs)
297{
298 VirtIOBlock *s;
299 int cylinders, heads, secs;
300 static int virtio_blk_id;
301
302 s = (VirtIOBlock *)virtio_init_pci(bus, "virtio-blk",
303 PCI_VENDOR_ID_REDHAT_QUMRANET,
304 PCI_DEVICE_ID_VIRTIO_BLOCK,
305 PCI_VENDOR_ID_REDHAT_QUMRANET,
306 VIRTIO_ID_BLOCK,
307 PCI_CLASS_STORAGE_OTHER, 0x00,
308 sizeof(struct virtio_blk_config), sizeof(VirtIOBlock));
309 if (!s)
310 return NULL;
311
312 s->vdev.get_config = virtio_blk_update_config;
313 s->vdev.get_features = virtio_blk_get_features;
314 s->vdev.reset = virtio_blk_reset;
315 s->bs = bs;
316 s->rq = NULL;
317 bs->private = &s->vdev.pci_dev;
318 bdrv_guess_geometry(s->bs, &cylinders, &heads, &secs);
319 bdrv_set_geometry_hint(s->bs, cylinders, heads, secs);
320
321 s->vq = virtio_add_queue(&s->vdev, 128, virtio_blk_handle_output);
322
323 qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
324 register_savevm("virtio-blk", virtio_blk_id++, 2,
325 virtio_blk_save, virtio_blk_load, s);
326
327 return s;
328}
329
