Statistics
| Branch: | Revision:

root / hw / xen_nic.c @ bb6e6364

History | View | Annotate | Download (12 kB)

1
/*
2
 *  xen paravirt network card backend
3
 *
4
 *  (c) Gerd Hoffmann <kraxel@redhat.com>
5
 *
6
 *  This program is free software; you can redistribute it and/or modify
7
 *  it under the terms of the GNU General Public License as published by
8
 *  the Free Software Foundation; under version 2 of the License.
9
 *
10
 *  This program is distributed in the hope that it will be useful,
11
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13
 *  GNU General Public License for more details.
14
 *
15
 *  You should have received a copy of the GNU General Public License along
16
 *  with this program; if not, see <http://www.gnu.org/licenses/>.
17
 */
18

    
19
#include <stdio.h>
20
#include <stdlib.h>
21
#include <stdarg.h>
22
#include <string.h>
23
#include <unistd.h>
24
#include <signal.h>
25
#include <inttypes.h>
26
#include <fcntl.h>
27
#include <errno.h>
28
#include <pthread.h>
29
#include <sys/socket.h>
30
#include <sys/ioctl.h>
31
#include <sys/types.h>
32
#include <sys/stat.h>
33
#include <sys/mman.h>
34
#include <sys/wait.h>
35

    
36
#include <xs.h>
37
#include <xenctrl.h>
38
#include <xen/io/xenbus.h>
39
#include <xen/io/netif.h>
40

    
41
#include "hw.h"
42
#include "net.h"
43
#include "qemu-char.h"
44
#include "xen_backend.h"
45

    
46
/* ------------------------------------------------------------- */
47

    
48
struct XenNetDev {
49
    struct XenDevice      xendev;  /* must be first */
50
    char                  *mac;
51
    int                   tx_work;
52
    int                   tx_ring_ref;
53
    int                   rx_ring_ref;
54
    struct netif_tx_sring *txs;
55
    struct netif_rx_sring *rxs;
56
    netif_tx_back_ring_t  tx_ring;
57
    netif_rx_back_ring_t  rx_ring;
58
    VLANClientState       *vs;
59
};
60

    
61
/* ------------------------------------------------------------- */
62

    
63
static void net_tx_response(struct XenNetDev *netdev, netif_tx_request_t *txp, int8_t st)
64
{
65
    RING_IDX i = netdev->tx_ring.rsp_prod_pvt;
66
    netif_tx_response_t *resp;
67
    int notify;
68

    
69
    resp = RING_GET_RESPONSE(&netdev->tx_ring, i);
70
    resp->id     = txp->id;
71
    resp->status = st;
72

    
73
#if 0
74
    if (txp->flags & NETTXF_extra_info)
75
        RING_GET_RESPONSE(&netdev->tx_ring, ++i)->status = NETIF_RSP_NULL;
76
#endif
77

    
78
    netdev->tx_ring.rsp_prod_pvt = ++i;
79
    RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netdev->tx_ring, notify);
80
    if (notify)
81
        xen_be_send_notify(&netdev->xendev);
82

    
83
    if (i == netdev->tx_ring.req_cons) {
84
        int more_to_do;
85
        RING_FINAL_CHECK_FOR_REQUESTS(&netdev->tx_ring, more_to_do);
86
        if (more_to_do)
87
            netdev->tx_work++;
88
    }
89
}
90

    
91
static void net_tx_error(struct XenNetDev *netdev, netif_tx_request_t *txp, RING_IDX end)
92
{
93
#if 0
94
    /*
95
     * Hmm, why netback fails everything in the ring?
96
     * Should we do that even when not supporting SG and TSO?
97
     */
98
    RING_IDX cons = netdev->tx_ring.req_cons;
99

100
    do {
101
        make_tx_response(netif, txp, NETIF_RSP_ERROR);
102
        if (cons >= end)
103
            break;
104
        txp = RING_GET_REQUEST(&netdev->tx_ring, cons++);
105
    } while (1);
106
    netdev->tx_ring.req_cons = cons;
107
    netif_schedule_work(netif);
108
    netif_put(netif);
109
#else
110
    net_tx_response(netdev, txp, NETIF_RSP_ERROR);
111
#endif
112
}
113

    
114
static void net_tx_packets(struct XenNetDev *netdev)
115
{
116
    netif_tx_request_t txreq;
117
    RING_IDX rc, rp;
118
    void *page;
119
    void *tmpbuf = NULL;
120

    
121
    for (;;) {
122
        rc = netdev->tx_ring.req_cons;
123
        rp = netdev->tx_ring.sring->req_prod;
124
        xen_rmb(); /* Ensure we see queued requests up to 'rp'. */
125

    
126
        while ((rc != rp)) {
127
            if (RING_REQUEST_CONS_OVERFLOW(&netdev->tx_ring, rc))
128
                break;
129
            memcpy(&txreq, RING_GET_REQUEST(&netdev->tx_ring, rc), sizeof(txreq));
130
            netdev->tx_ring.req_cons = ++rc;
131

    
132
#if 1
133
            /* should not happen in theory, we don't announce the *
134
             * feature-{sg,gso,whatelse} flags in xenstore (yet?) */
135
            if (txreq.flags & NETTXF_extra_info) {
136
                xen_be_printf(&netdev->xendev, 0, "FIXME: extra info flag\n");
137
                net_tx_error(netdev, &txreq, rc);
138
                continue;
139
            }
140
            if (txreq.flags & NETTXF_more_data) {
141
                xen_be_printf(&netdev->xendev, 0, "FIXME: more data flag\n");
142
                net_tx_error(netdev, &txreq, rc);
143
                continue;
144
            }
145
#endif
146

    
147
            if (txreq.size < 14) {
148
                xen_be_printf(&netdev->xendev, 0, "bad packet size: %d\n", txreq.size);
149
                net_tx_error(netdev, &txreq, rc);
150
                continue;
151
            }
152

    
153
            if ((txreq.offset + txreq.size) > XC_PAGE_SIZE) {
154
                xen_be_printf(&netdev->xendev, 0, "error: page crossing\n");
155
                net_tx_error(netdev, &txreq, rc);
156
                continue;
157
            }
158

    
159
            xen_be_printf(&netdev->xendev, 3, "tx packet ref %d, off %d, len %d, flags 0x%x%s%s%s%s\n",
160
                          txreq.gref, txreq.offset, txreq.size, txreq.flags,
161
                          (txreq.flags & NETTXF_csum_blank)     ? " csum_blank"     : "",
162
                          (txreq.flags & NETTXF_data_validated) ? " data_validated" : "",
163
                          (txreq.flags & NETTXF_more_data)      ? " more_data"      : "",
164
                          (txreq.flags & NETTXF_extra_info)     ? " extra_info"     : "");
165

    
166
            page = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev,
167
                                           netdev->xendev.dom,
168
                                           txreq.gref, PROT_READ);
169
            if (page == NULL) {
170
                xen_be_printf(&netdev->xendev, 0, "error: tx gref dereference failed (%d)\n",
171
                              txreq.gref);
172
                net_tx_error(netdev, &txreq, rc);
173
                continue;
174
            }
175
            if (txreq.flags & NETTXF_csum_blank) {
176
                /* have read-only mapping -> can't fill checksum in-place */
177
                if (!tmpbuf)
178
                    tmpbuf = qemu_malloc(XC_PAGE_SIZE);
179
                memcpy(tmpbuf, page + txreq.offset, txreq.size);
180
                net_checksum_calculate(tmpbuf, txreq.size);
181
                qemu_send_packet(netdev->vs, tmpbuf, txreq.size);
182
            } else {
183
                qemu_send_packet(netdev->vs, page + txreq.offset, txreq.size);
184
            }
185
            xc_gnttab_munmap(netdev->xendev.gnttabdev, page, 1);
186
            net_tx_response(netdev, &txreq, NETIF_RSP_OKAY);
187
        }
188
        if (!netdev->tx_work)
189
            break;
190
        netdev->tx_work = 0;
191
    }
192
    qemu_free(tmpbuf);
193
}
194

    
195
/* ------------------------------------------------------------- */
196

    
197
static void net_rx_response(struct XenNetDev *netdev,
198
                            netif_rx_request_t *req, int8_t st,
199
                            uint16_t offset, uint16_t size,
200
                            uint16_t flags)
201
{
202
    RING_IDX i = netdev->rx_ring.rsp_prod_pvt;
203
    netif_rx_response_t *resp;
204
    int notify;
205

    
206
    resp = RING_GET_RESPONSE(&netdev->rx_ring, i);
207
    resp->offset     = offset;
208
    resp->flags      = flags;
209
    resp->id         = req->id;
210
    resp->status     = (int16_t)size;
211
    if (st < 0)
212
        resp->status = (int16_t)st;
213

    
214
    xen_be_printf(&netdev->xendev, 3, "rx response: idx %d, status %d, flags 0x%x\n",
215
                  i, resp->status, resp->flags);
216

    
217
    netdev->rx_ring.rsp_prod_pvt = ++i;
218
    RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netdev->rx_ring, notify);
219
    if (notify)
220
        xen_be_send_notify(&netdev->xendev);
221
}
222

    
223
#define NET_IP_ALIGN 2
224

    
225
static int net_rx_ok(VLANClientState *vc)
226
{
227
    struct XenNetDev *netdev = vc->opaque;
228
    RING_IDX rc, rp;
229

    
230
    if (netdev->xendev.be_state != XenbusStateConnected)
231
        return 0;
232

    
233
    rc = netdev->rx_ring.req_cons;
234
    rp = netdev->rx_ring.sring->req_prod;
235
    xen_rmb();
236

    
237
    if (rc == rp || RING_REQUEST_CONS_OVERFLOW(&netdev->rx_ring, rc)) {
238
        xen_be_printf(&netdev->xendev, 2, "%s: no rx buffers (%d/%d)\n",
239
                      __FUNCTION__, rc, rp);
240
        return 0;
241
    }
242
    return 1;
243
}
244

    
245
static ssize_t net_rx_packet(VLANClientState *vc, const uint8_t *buf, size_t size)
246
{
247
    struct XenNetDev *netdev = vc->opaque;
248
    netif_rx_request_t rxreq;
249
    RING_IDX rc, rp;
250
    void *page;
251

    
252
    if (netdev->xendev.be_state != XenbusStateConnected)
253
        return -1;
254

    
255
    rc = netdev->rx_ring.req_cons;
256
    rp = netdev->rx_ring.sring->req_prod;
257
    xen_rmb(); /* Ensure we see queued requests up to 'rp'. */
258

    
259
    if (rc == rp || RING_REQUEST_CONS_OVERFLOW(&netdev->rx_ring, rc)) {
260
        xen_be_printf(&netdev->xendev, 2, "no buffer, drop packet\n");
261
        return -1;
262
    }
263
    if (size > XC_PAGE_SIZE - NET_IP_ALIGN) {
264
        xen_be_printf(&netdev->xendev, 0, "packet too big (%lu > %ld)",
265
                      (unsigned long)size, XC_PAGE_SIZE - NET_IP_ALIGN);
266
        return -1;
267
    }
268

    
269
    memcpy(&rxreq, RING_GET_REQUEST(&netdev->rx_ring, rc), sizeof(rxreq));
270
    netdev->rx_ring.req_cons = ++rc;
271

    
272
    page = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev,
273
                                   netdev->xendev.dom,
274
                                   rxreq.gref, PROT_WRITE);
275
    if (page == NULL) {
276
        xen_be_printf(&netdev->xendev, 0, "error: rx gref dereference failed (%d)\n",
277
                      rxreq.gref);
278
        net_rx_response(netdev, &rxreq, NETIF_RSP_ERROR, 0, 0, 0);
279
        return -1;
280
    }
281
    memcpy(page + NET_IP_ALIGN, buf, size);
282
    xc_gnttab_munmap(netdev->xendev.gnttabdev, page, 1);
283
    net_rx_response(netdev, &rxreq, NETIF_RSP_OKAY, NET_IP_ALIGN, size, 0);
284

    
285
    return size;
286
}
287

    
288
/* ------------------------------------------------------------- */
289

    
290
static int net_init(struct XenDevice *xendev)
291
{
292
    struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev);
293
    VLANState *vlan;
294

    
295
    /* read xenstore entries */
296
    if (netdev->mac == NULL)
297
        netdev->mac = xenstore_read_be_str(&netdev->xendev, "mac");
298

    
299
    /* do we have all we need? */
300
    if (netdev->mac == NULL)
301
        return -1;
302

    
303
    vlan = qemu_find_vlan(netdev->xendev.dev, 1);
304
    netdev->vs = qemu_new_vlan_client(NET_CLIENT_TYPE_NIC,
305
                                      vlan, NULL, "xen", NULL,
306
                                      net_rx_ok, net_rx_packet, NULL,
307
                                      NULL, netdev);
308
    snprintf(netdev->vs->info_str, sizeof(netdev->vs->info_str),
309
             "nic: xenbus vif macaddr=%s", netdev->mac);
310

    
311
    /* fill info */
312
    xenstore_write_be_int(&netdev->xendev, "feature-rx-copy", 1);
313
    xenstore_write_be_int(&netdev->xendev, "feature-rx-flip", 0);
314

    
315
    return 0;
316
}
317

    
318
static int net_connect(struct XenDevice *xendev)
319
{
320
    struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev);
321
    int rx_copy;
322

    
323
    if (xenstore_read_fe_int(&netdev->xendev, "tx-ring-ref",
324
                                   &netdev->tx_ring_ref) == -1)
325
        return -1;
326
    if (xenstore_read_fe_int(&netdev->xendev, "rx-ring-ref",
327
                                   &netdev->rx_ring_ref) == -1)
328
        return 1;
329
    if (xenstore_read_fe_int(&netdev->xendev, "event-channel",
330
                                   &netdev->xendev.remote_port) == -1)
331
        return -1;
332

    
333
    if (xenstore_read_fe_int(&netdev->xendev, "request-rx-copy", &rx_copy) == -1)
334
        rx_copy = 0;
335
    if (rx_copy == 0) {
336
        xen_be_printf(&netdev->xendev, 0, "frontend doesn't support rx-copy.\n");
337
        return -1;
338
    }
339

    
340
    netdev->txs = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev,
341
                                          netdev->xendev.dom,
342
                                          netdev->tx_ring_ref,
343
                                          PROT_READ | PROT_WRITE);
344
    netdev->rxs = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev,
345
                                          netdev->xendev.dom,
346
                                          netdev->rx_ring_ref,
347
                                          PROT_READ | PROT_WRITE);
348
    if (!netdev->txs || !netdev->rxs)
349
        return -1;
350
    BACK_RING_INIT(&netdev->tx_ring, netdev->txs, XC_PAGE_SIZE);
351
    BACK_RING_INIT(&netdev->rx_ring, netdev->rxs, XC_PAGE_SIZE);
352

    
353
    xen_be_bind_evtchn(&netdev->xendev);
354

    
355
    xen_be_printf(&netdev->xendev, 1, "ok: tx-ring-ref %d, rx-ring-ref %d, "
356
                  "remote port %d, local port %d\n",
357
                  netdev->tx_ring_ref, netdev->rx_ring_ref,
358
                  netdev->xendev.remote_port, netdev->xendev.local_port);
359

    
360
    net_tx_packets(netdev);
361
    return 0;
362
}
363

    
364
static void net_disconnect(struct XenDevice *xendev)
365
{
366
    struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev);
367

    
368
    xen_be_unbind_evtchn(&netdev->xendev);
369

    
370
    if (netdev->txs) {
371
        xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->txs, 1);
372
        netdev->txs = NULL;
373
    }
374
    if (netdev->rxs) {
375
        xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->rxs, 1);
376
        netdev->rxs = NULL;
377
    }
378
    if (netdev->vs) {
379
        qemu_del_vlan_client(netdev->vs);
380
        netdev->vs = NULL;
381
    }
382
}
383

    
384
static void net_event(struct XenDevice *xendev)
385
{
386
    struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev);
387
    net_tx_packets(netdev);
388
}
389

    
390
static int net_free(struct XenDevice *xendev)
391
{
392
    struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev);
393

    
394
    qemu_free(netdev->mac);
395
    return 0;
396
}
397

    
398
/* ------------------------------------------------------------- */
399

    
400
struct XenDevOps xen_netdev_ops = {
401
    .size       = sizeof(struct XenNetDev),
402
    .flags      = DEVOPS_FLAG_NEED_GNTDEV,
403
    .init       = net_init,
404
    .connect    = net_connect,
405
    .event      = net_event,
406
    .disconnect = net_disconnect,
407
    .free       = net_free,
408
};