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11#include "qemu/osdep.h"
12
13#include "hw/hw.h"
14#include "hw/9pfs/9p.h"
15#include "hw/xen/xen-legacy-backend.h"
16#include "hw/9pfs/xen-9pfs.h"
17#include "qapi/error.h"
18#include "qemu/config-file.h"
19#include "qemu/option.h"
20#include "fsdev/qemu-fsdev.h"
21
22#define VERSIONS "1"
23#define MAX_RINGS 8
24#define MAX_RING_ORDER 8
25
26typedef struct Xen9pfsRing {
27 struct Xen9pfsDev *priv;
28
29 int ref;
30 xenevtchn_handle *evtchndev;
31 int evtchn;
32 int local_port;
33 int ring_order;
34 struct xen_9pfs_data_intf *intf;
35 unsigned char *data;
36 struct xen_9pfs_data ring;
37
38 struct iovec *sg;
39 QEMUBH *bh;
40
41
42
43 RING_IDX out_cons, out_size, in_cons;
44 bool inprogress;
45} Xen9pfsRing;
46
47typedef struct Xen9pfsDev {
48 struct XenLegacyDevice xendev;
49 V9fsState state;
50 char *path;
51 char *security_model;
52 char *tag;
53 char *id;
54
55 int num_rings;
56 Xen9pfsRing *rings;
57} Xen9pfsDev;
58
59static void xen_9pfs_disconnect(struct XenLegacyDevice *xendev);
60
61static void xen_9pfs_in_sg(Xen9pfsRing *ring,
62 struct iovec *in_sg,
63 int *num,
64 uint32_t idx,
65 uint32_t size)
66{
67 RING_IDX cons, prod, masked_prod, masked_cons;
68
69 cons = ring->intf->in_cons;
70 prod = ring->intf->in_prod;
71 xen_rmb();
72 masked_prod = xen_9pfs_mask(prod, XEN_FLEX_RING_SIZE(ring->ring_order));
73 masked_cons = xen_9pfs_mask(cons, XEN_FLEX_RING_SIZE(ring->ring_order));
74
75 if (masked_prod < masked_cons) {
76 in_sg[0].iov_base = ring->ring.in + masked_prod;
77 in_sg[0].iov_len = masked_cons - masked_prod;
78 *num = 1;
79 } else {
80 in_sg[0].iov_base = ring->ring.in + masked_prod;
81 in_sg[0].iov_len = XEN_FLEX_RING_SIZE(ring->ring_order) - masked_prod;
82 in_sg[1].iov_base = ring->ring.in;
83 in_sg[1].iov_len = masked_cons;
84 *num = 2;
85 }
86}
87
88static void xen_9pfs_out_sg(Xen9pfsRing *ring,
89 struct iovec *out_sg,
90 int *num,
91 uint32_t idx)
92{
93 RING_IDX cons, prod, masked_prod, masked_cons;
94
95 cons = ring->intf->out_cons;
96 prod = ring->intf->out_prod;
97 xen_rmb();
98 masked_prod = xen_9pfs_mask(prod, XEN_FLEX_RING_SIZE(ring->ring_order));
99 masked_cons = xen_9pfs_mask(cons, XEN_FLEX_RING_SIZE(ring->ring_order));
100
101 if (masked_cons < masked_prod) {
102 out_sg[0].iov_base = ring->ring.out + masked_cons;
103 out_sg[0].iov_len = ring->out_size;
104 *num = 1;
105 } else {
106 if (ring->out_size >
107 (XEN_FLEX_RING_SIZE(ring->ring_order) - masked_cons)) {
108 out_sg[0].iov_base = ring->ring.out + masked_cons;
109 out_sg[0].iov_len = XEN_FLEX_RING_SIZE(ring->ring_order) -
110 masked_cons;
111 out_sg[1].iov_base = ring->ring.out;
112 out_sg[1].iov_len = ring->out_size -
113 (XEN_FLEX_RING_SIZE(ring->ring_order) -
114 masked_cons);
115 *num = 2;
116 } else {
117 out_sg[0].iov_base = ring->ring.out + masked_cons;
118 out_sg[0].iov_len = ring->out_size;
119 *num = 1;
120 }
121 }
122}
123
124static ssize_t xen_9pfs_pdu_vmarshal(V9fsPDU *pdu,
125 size_t offset,
126 const char *fmt,
127 va_list ap)
128{
129 Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
130 struct iovec in_sg[2];
131 int num;
132 ssize_t ret;
133
134 xen_9pfs_in_sg(&xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings],
135 in_sg, &num, pdu->idx, ROUND_UP(offset + 128, 512));
136
137 ret = v9fs_iov_vmarshal(in_sg, num, offset, 0, fmt, ap);
138 if (ret < 0) {
139 xen_pv_printf(&xen_9pfs->xendev, 0,
140 "Failed to encode VirtFS request type %d\n", pdu->id + 1);
141 xen_be_set_state(&xen_9pfs->xendev, XenbusStateClosing);
142 xen_9pfs_disconnect(&xen_9pfs->xendev);
143 }
144 return ret;
145}
146
147static ssize_t xen_9pfs_pdu_vunmarshal(V9fsPDU *pdu,
148 size_t offset,
149 const char *fmt,
150 va_list ap)
151{
152 Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
153 struct iovec out_sg[2];
154 int num;
155 ssize_t ret;
156
157 xen_9pfs_out_sg(&xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings],
158 out_sg, &num, pdu->idx);
159
160 ret = v9fs_iov_vunmarshal(out_sg, num, offset, 0, fmt, ap);
161 if (ret < 0) {
162 xen_pv_printf(&xen_9pfs->xendev, 0,
163 "Failed to decode VirtFS request type %d\n", pdu->id);
164 xen_be_set_state(&xen_9pfs->xendev, XenbusStateClosing);
165 xen_9pfs_disconnect(&xen_9pfs->xendev);
166 }
167 return ret;
168}
169
170static void xen_9pfs_init_out_iov_from_pdu(V9fsPDU *pdu,
171 struct iovec **piov,
172 unsigned int *pniov,
173 size_t size)
174{
175 Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
176 Xen9pfsRing *ring = &xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings];
177 int num;
178
179 g_free(ring->sg);
180
181 ring->sg = g_new0(struct iovec, 2);
182 xen_9pfs_out_sg(ring, ring->sg, &num, pdu->idx);
183 *piov = ring->sg;
184 *pniov = num;
185}
186
187static void xen_9pfs_init_in_iov_from_pdu(V9fsPDU *pdu,
188 struct iovec **piov,
189 unsigned int *pniov,
190 size_t size)
191{
192 Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
193 Xen9pfsRing *ring = &xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings];
194 int num;
195 size_t buf_size;
196
197 g_free(ring->sg);
198
199 ring->sg = g_new0(struct iovec, 2);
200 xen_9pfs_in_sg(ring, ring->sg, &num, pdu->idx, size);
201
202 buf_size = iov_size(ring->sg, num);
203 if (buf_size < size) {
204 xen_pv_printf(&xen_9pfs->xendev, 0, "Xen 9pfs request type %d"
205 "needs %zu bytes, buffer has %zu\n", pdu->id, size,
206 buf_size);
207 xen_be_set_state(&xen_9pfs->xendev, XenbusStateClosing);
208 xen_9pfs_disconnect(&xen_9pfs->xendev);
209 }
210
211 *piov = ring->sg;
212 *pniov = num;
213}
214
215static void xen_9pfs_push_and_notify(V9fsPDU *pdu)
216{
217 RING_IDX prod;
218 Xen9pfsDev *priv = container_of(pdu->s, Xen9pfsDev, state);
219 Xen9pfsRing *ring = &priv->rings[pdu->tag % priv->num_rings];
220
221 g_free(ring->sg);
222 ring->sg = NULL;
223
224 ring->intf->out_cons = ring->out_cons;
225 xen_wmb();
226
227 prod = ring->intf->in_prod;
228 xen_rmb();
229 ring->intf->in_prod = prod + pdu->size;
230 xen_wmb();
231
232 ring->inprogress = false;
233 xenevtchn_notify(ring->evtchndev, ring->local_port);
234
235 qemu_bh_schedule(ring->bh);
236}
237
238static const V9fsTransport xen_9p_transport = {
239 .pdu_vmarshal = xen_9pfs_pdu_vmarshal,
240 .pdu_vunmarshal = xen_9pfs_pdu_vunmarshal,
241 .init_in_iov_from_pdu = xen_9pfs_init_in_iov_from_pdu,
242 .init_out_iov_from_pdu = xen_9pfs_init_out_iov_from_pdu,
243 .push_and_notify = xen_9pfs_push_and_notify,
244};
245
246static int xen_9pfs_init(struct XenLegacyDevice *xendev)
247{
248 return 0;
249}
250
251static int xen_9pfs_receive(Xen9pfsRing *ring)
252{
253 P9MsgHeader h;
254 RING_IDX cons, prod, masked_prod, masked_cons, queued;
255 V9fsPDU *pdu;
256
257 if (ring->inprogress) {
258 return 0;
259 }
260
261 cons = ring->intf->out_cons;
262 prod = ring->intf->out_prod;
263 xen_rmb();
264
265 queued = xen_9pfs_queued(prod, cons, XEN_FLEX_RING_SIZE(ring->ring_order));
266 if (queued < sizeof(h)) {
267 return 0;
268 }
269 ring->inprogress = true;
270
271 masked_prod = xen_9pfs_mask(prod, XEN_FLEX_RING_SIZE(ring->ring_order));
272 masked_cons = xen_9pfs_mask(cons, XEN_FLEX_RING_SIZE(ring->ring_order));
273
274 xen_9pfs_read_packet((uint8_t *) &h, ring->ring.out, sizeof(h),
275 masked_prod, &masked_cons,
276 XEN_FLEX_RING_SIZE(ring->ring_order));
277 if (queued < le32_to_cpu(h.size_le)) {
278 return 0;
279 }
280
281
282 pdu = pdu_alloc(&ring->priv->state);
283 ring->out_size = le32_to_cpu(h.size_le);
284 ring->out_cons = cons + le32_to_cpu(h.size_le);
285
286 pdu_submit(pdu, &h);
287
288 return 0;
289}
290
291static void xen_9pfs_bh(void *opaque)
292{
293 Xen9pfsRing *ring = opaque;
294 xen_9pfs_receive(ring);
295}
296
297static void xen_9pfs_evtchn_event(void *opaque)
298{
299 Xen9pfsRing *ring = opaque;
300 evtchn_port_t port;
301
302 port = xenevtchn_pending(ring->evtchndev);
303 xenevtchn_unmask(ring->evtchndev, port);
304
305 qemu_bh_schedule(ring->bh);
306}
307
308static void xen_9pfs_disconnect(struct XenLegacyDevice *xendev)
309{
310 Xen9pfsDev *xen_9pdev = container_of(xendev, Xen9pfsDev, xendev);
311 int i;
312
313 for (i = 0; i < xen_9pdev->num_rings; i++) {
314 if (xen_9pdev->rings[i].evtchndev != NULL) {
315 qemu_set_fd_handler(xenevtchn_fd(xen_9pdev->rings[i].evtchndev),
316 NULL, NULL, NULL);
317 xenevtchn_unbind(xen_9pdev->rings[i].evtchndev,
318 xen_9pdev->rings[i].local_port);
319 xen_9pdev->rings[i].evtchndev = NULL;
320 }
321 }
322}
323
324static int xen_9pfs_free(struct XenLegacyDevice *xendev)
325{
326 Xen9pfsDev *xen_9pdev = container_of(xendev, Xen9pfsDev, xendev);
327 int i;
328
329 if (xen_9pdev->rings[0].evtchndev != NULL) {
330 xen_9pfs_disconnect(xendev);
331 }
332
333 for (i = 0; i < xen_9pdev->num_rings; i++) {
334 if (xen_9pdev->rings[i].data != NULL) {
335 xen_be_unmap_grant_refs(&xen_9pdev->xendev,
336 xen_9pdev->rings[i].data,
337 (1 << xen_9pdev->rings[i].ring_order));
338 }
339 if (xen_9pdev->rings[i].intf != NULL) {
340 xen_be_unmap_grant_refs(&xen_9pdev->xendev,
341 xen_9pdev->rings[i].intf,
342 1);
343 }
344 if (xen_9pdev->rings[i].bh != NULL) {
345 qemu_bh_delete(xen_9pdev->rings[i].bh);
346 }
347 }
348
349 g_free(xen_9pdev->id);
350 g_free(xen_9pdev->tag);
351 g_free(xen_9pdev->path);
352 g_free(xen_9pdev->security_model);
353 g_free(xen_9pdev->rings);
354 return 0;
355}
356
357static int xen_9pfs_connect(struct XenLegacyDevice *xendev)
358{
359 Error *err = NULL;
360 int i;
361 Xen9pfsDev *xen_9pdev = container_of(xendev, Xen9pfsDev, xendev);
362 V9fsState *s = &xen_9pdev->state;
363 QemuOpts *fsdev;
364
365 if (xenstore_read_fe_int(&xen_9pdev->xendev, "num-rings",
366 &xen_9pdev->num_rings) == -1 ||
367 xen_9pdev->num_rings > MAX_RINGS || xen_9pdev->num_rings < 1) {
368 return -1;
369 }
370
371 xen_9pdev->rings = g_new0(Xen9pfsRing, xen_9pdev->num_rings);
372 for (i = 0; i < xen_9pdev->num_rings; i++) {
373 char *str;
374 int ring_order;
375
376 xen_9pdev->rings[i].priv = xen_9pdev;
377 xen_9pdev->rings[i].evtchn = -1;
378 xen_9pdev->rings[i].local_port = -1;
379
380 str = g_strdup_printf("ring-ref%u", i);
381 if (xenstore_read_fe_int(&xen_9pdev->xendev, str,
382 &xen_9pdev->rings[i].ref) == -1) {
383 g_free(str);
384 goto out;
385 }
386 g_free(str);
387 str = g_strdup_printf("event-channel-%u", i);
388 if (xenstore_read_fe_int(&xen_9pdev->xendev, str,
389 &xen_9pdev->rings[i].evtchn) == -1) {
390 g_free(str);
391 goto out;
392 }
393 g_free(str);
394
395 xen_9pdev->rings[i].intf =
396 xen_be_map_grant_ref(&xen_9pdev->xendev,
397 xen_9pdev->rings[i].ref,
398 PROT_READ | PROT_WRITE);
399 if (!xen_9pdev->rings[i].intf) {
400 goto out;
401 }
402 ring_order = xen_9pdev->rings[i].intf->ring_order;
403 if (ring_order > MAX_RING_ORDER) {
404 goto out;
405 }
406 xen_9pdev->rings[i].ring_order = ring_order;
407 xen_9pdev->rings[i].data =
408 xen_be_map_grant_refs(&xen_9pdev->xendev,
409 xen_9pdev->rings[i].intf->ref,
410 (1 << ring_order),
411 PROT_READ | PROT_WRITE);
412 if (!xen_9pdev->rings[i].data) {
413 goto out;
414 }
415 xen_9pdev->rings[i].ring.in = xen_9pdev->rings[i].data;
416 xen_9pdev->rings[i].ring.out = xen_9pdev->rings[i].data +
417 XEN_FLEX_RING_SIZE(ring_order);
418
419 xen_9pdev->rings[i].bh = qemu_bh_new(xen_9pfs_bh, &xen_9pdev->rings[i]);
420 xen_9pdev->rings[i].out_cons = 0;
421 xen_9pdev->rings[i].out_size = 0;
422 xen_9pdev->rings[i].inprogress = false;
423
424
425 xen_9pdev->rings[i].evtchndev = xenevtchn_open(NULL, 0);
426 if (xen_9pdev->rings[i].evtchndev == NULL) {
427 goto out;
428 }
429 qemu_set_cloexec(xenevtchn_fd(xen_9pdev->rings[i].evtchndev));
430 xen_9pdev->rings[i].local_port = xenevtchn_bind_interdomain
431 (xen_9pdev->rings[i].evtchndev,
432 xendev->dom,
433 xen_9pdev->rings[i].evtchn);
434 if (xen_9pdev->rings[i].local_port == -1) {
435 xen_pv_printf(xendev, 0,
436 "xenevtchn_bind_interdomain failed port=%d\n",
437 xen_9pdev->rings[i].evtchn);
438 goto out;
439 }
440 xen_pv_printf(xendev, 2, "bind evtchn port %d\n", xendev->local_port);
441 qemu_set_fd_handler(xenevtchn_fd(xen_9pdev->rings[i].evtchndev),
442 xen_9pfs_evtchn_event, NULL, &xen_9pdev->rings[i]);
443 }
444
445 xen_9pdev->security_model = xenstore_read_be_str(xendev, "security_model");
446 xen_9pdev->path = xenstore_read_be_str(xendev, "path");
447 xen_9pdev->id = s->fsconf.fsdev_id =
448 g_strdup_printf("xen9p%d", xendev->dev);
449 xen_9pdev->tag = s->fsconf.tag = xenstore_read_fe_str(xendev, "tag");
450 fsdev = qemu_opts_create(qemu_find_opts("fsdev"),
451 s->fsconf.tag,
452 1, NULL);
453 qemu_opt_set(fsdev, "fsdriver", "local", NULL);
454 qemu_opt_set(fsdev, "path", xen_9pdev->path, NULL);
455 qemu_opt_set(fsdev, "security_model", xen_9pdev->security_model, NULL);
456 qemu_opts_set_id(fsdev, s->fsconf.fsdev_id);
457 qemu_fsdev_add(fsdev, &err);
458 if (err) {
459 error_report_err(err);
460 }
461 v9fs_device_realize_common(s, &xen_9p_transport, NULL);
462
463 return 0;
464
465out:
466 xen_9pfs_free(xendev);
467 return -1;
468}
469
470static void xen_9pfs_alloc(struct XenLegacyDevice *xendev)
471{
472 xenstore_write_be_str(xendev, "versions", VERSIONS);
473 xenstore_write_be_int(xendev, "max-rings", MAX_RINGS);
474 xenstore_write_be_int(xendev, "max-ring-page-order", MAX_RING_ORDER);
475}
476
477struct XenDevOps xen_9pfs_ops = {
478 .size = sizeof(Xen9pfsDev),
479 .flags = DEVOPS_FLAG_NEED_GNTDEV,
480 .alloc = xen_9pfs_alloc,
481 .init = xen_9pfs_init,
482 .initialise = xen_9pfs_connect,
483 .disconnect = xen_9pfs_disconnect,
484 .free = xen_9pfs_free,
485};
486
