xref: /openbmc/qemu/hw/net/spapr_llan.c (revision a6caeee8)
1 /*
2  * QEMU PowerPC pSeries Logical Partition (aka sPAPR) hardware System Emulator
3  *
4  * PAPR Inter-VM Logical Lan, aka ibmveth
5  *
6  * Copyright (c) 2010,2011 David Gibson, IBM Corporation.
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a copy
9  * of this software and associated documentation files (the "Software"), to deal
10  * in the Software without restriction, including without limitation the rights
11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12  * copies of the Software, and to permit persons to whom the Software is
13  * furnished to do so, subject to the following conditions:
14  *
15  * The above copyright notice and this permission notice shall be included in
16  * all copies or substantial portions of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24  * THE SOFTWARE.
25  *
26  */
27 
28 #include "qemu/osdep.h"
29 #include "qemu/log.h"
30 #include "qemu/module.h"
31 #include "net/net.h"
32 #include "migration/vmstate.h"
33 #include "hw/ppc/spapr.h"
34 #include "hw/ppc/spapr_vio.h"
35 #include "hw/qdev-properties.h"
36 #include "sysemu/sysemu.h"
37 #include "trace.h"
38 
39 #include <libfdt.h>
40 #include "qom/object.h"
41 
42 #define ETH_ALEN        6
43 #define MAX_PACKET_SIZE 65536
44 
45 /* Compatibility flags for migration */
46 #define SPAPRVLAN_FLAG_RX_BUF_POOLS_BIT  0
47 #define SPAPRVLAN_FLAG_RX_BUF_POOLS      (1 << SPAPRVLAN_FLAG_RX_BUF_POOLS_BIT)
48 
49 /*
50  * Virtual LAN device
51  */
52 
53 typedef uint64_t vlan_bd_t;
54 
55 #define VLAN_BD_VALID        0x8000000000000000ULL
56 #define VLAN_BD_TOGGLE       0x4000000000000000ULL
57 #define VLAN_BD_NO_CSUM      0x0200000000000000ULL
58 #define VLAN_BD_CSUM_GOOD    0x0100000000000000ULL
59 #define VLAN_BD_LEN_MASK     0x00ffffff00000000ULL
60 #define VLAN_BD_LEN(bd)      (((bd) & VLAN_BD_LEN_MASK) >> 32)
61 #define VLAN_BD_ADDR_MASK    0x00000000ffffffffULL
62 #define VLAN_BD_ADDR(bd)     ((bd) & VLAN_BD_ADDR_MASK)
63 
64 #define VLAN_VALID_BD(addr, len) (VLAN_BD_VALID | \
65                                   (((len) << 32) & VLAN_BD_LEN_MASK) |  \
66                                   (addr & VLAN_BD_ADDR_MASK))
67 
68 #define VLAN_RXQC_TOGGLE     0x80
69 #define VLAN_RXQC_VALID      0x40
70 #define VLAN_RXQC_NO_CSUM    0x02
71 #define VLAN_RXQC_CSUM_GOOD  0x01
72 
73 #define VLAN_RQ_ALIGNMENT    16
74 #define VLAN_RXQ_BD_OFF      0
75 #define VLAN_FILTER_BD_OFF   8
76 #define VLAN_RX_BDS_OFF      16
77 /*
78  * The final 8 bytes of the buffer list is a counter of frames dropped
79  * because there was not a buffer in the buffer list capable of holding
80  * the frame. We must avoid it, or the operating system will report garbage
81  * for this statistic.
82  */
83 #define VLAN_RX_BDS_LEN      (SPAPR_TCE_PAGE_SIZE - VLAN_RX_BDS_OFF - 8)
84 #define VLAN_MAX_BUFS        (VLAN_RX_BDS_LEN / 8)
85 
86 #define TYPE_VIO_SPAPR_VLAN_DEVICE "spapr-vlan"
87 OBJECT_DECLARE_SIMPLE_TYPE(SpaprVioVlan, VIO_SPAPR_VLAN_DEVICE)
88 
89 #define RX_POOL_MAX_BDS 4096
90 #define RX_MAX_POOLS 5
91 
92 typedef struct {
93     int32_t bufsize;
94     int32_t count;
95     vlan_bd_t bds[RX_POOL_MAX_BDS];
96 } RxBufPool;
97 
98 struct SpaprVioVlan {
99     SpaprVioDevice sdev;
100     NICConf nicconf;
101     NICState *nic;
102     MACAddr perm_mac;
103     bool isopen;
104     hwaddr buf_list;
105     uint32_t add_buf_ptr, use_buf_ptr, rx_bufs;
106     hwaddr rxq_ptr;
107     QEMUTimer *rxp_timer;
108     uint32_t compat_flags;             /* Compatibility flags for migration */
109     RxBufPool *rx_pool[RX_MAX_POOLS];  /* Receive buffer descriptor pools */
110 };
111 
112 static bool spapr_vlan_can_receive(NetClientState *nc)
113 {
114     SpaprVioVlan *dev = qemu_get_nic_opaque(nc);
115 
116     return dev->isopen && dev->rx_bufs > 0;
117 }
118 
119 /**
120  * The last 8 bytes of the receive buffer list page (that has been
121  * supplied by the guest with the H_REGISTER_LOGICAL_LAN call) contain
122  * a counter for frames that have been dropped because there was no
123  * suitable receive buffer available. This function is used to increase
124  * this counter by one.
125  */
126 static void spapr_vlan_record_dropped_rx_frame(SpaprVioVlan *dev)
127 {
128     uint64_t cnt;
129 
130     cnt = vio_ldq(&dev->sdev, dev->buf_list + 4096 - 8);
131     vio_stq(&dev->sdev, dev->buf_list + 4096 - 8, cnt + 1);
132 }
133 
134 /**
135  * Get buffer descriptor from one of our receive buffer pools
136  */
137 static vlan_bd_t spapr_vlan_get_rx_bd_from_pool(SpaprVioVlan *dev,
138                                                 size_t size)
139 {
140     vlan_bd_t bd;
141     int pool;
142 
143     for (pool = 0; pool < RX_MAX_POOLS; pool++) {
144         if (dev->rx_pool[pool]->count > 0 &&
145             dev->rx_pool[pool]->bufsize >= size + 8) {
146             break;
147         }
148     }
149     if (pool == RX_MAX_POOLS) {
150         /* Failed to find a suitable buffer */
151         return 0;
152     }
153 
154 
155     trace_spapr_vlan_get_rx_bd_from_pool_found(pool,
156                                                dev->rx_pool[pool]->count,
157                                                dev->rx_bufs);
158 
159     /* Remove the buffer from the pool */
160     dev->rx_pool[pool]->count--;
161     bd = dev->rx_pool[pool]->bds[dev->rx_pool[pool]->count];
162     dev->rx_pool[pool]->bds[dev->rx_pool[pool]->count] = 0;
163 
164     return bd;
165 }
166 
167 /**
168  * Get buffer descriptor from the receive buffer list page that has been
169  * supplied by the guest with the H_REGISTER_LOGICAL_LAN call
170  */
171 static vlan_bd_t spapr_vlan_get_rx_bd_from_page(SpaprVioVlan *dev,
172                                                 size_t size)
173 {
174     int buf_ptr = dev->use_buf_ptr;
175     vlan_bd_t bd;
176 
177     do {
178         buf_ptr += 8;
179         if (buf_ptr >= VLAN_RX_BDS_LEN + VLAN_RX_BDS_OFF) {
180             buf_ptr = VLAN_RX_BDS_OFF;
181         }
182 
183         bd = vio_ldq(&dev->sdev, dev->buf_list + buf_ptr);
184 
185         trace_spapr_vlan_get_rx_bd_from_page(buf_ptr, (uint64_t)bd);
186     } while ((!(bd & VLAN_BD_VALID) || VLAN_BD_LEN(bd) < size + 8)
187              && buf_ptr != dev->use_buf_ptr);
188 
189     if (!(bd & VLAN_BD_VALID) || VLAN_BD_LEN(bd) < size + 8) {
190         /* Failed to find a suitable buffer */
191         return 0;
192     }
193 
194     /* Remove the buffer from the pool */
195     dev->use_buf_ptr = buf_ptr;
196     vio_stq(&dev->sdev, dev->buf_list + dev->use_buf_ptr, 0);
197 
198     trace_spapr_vlan_get_rx_bd_from_page_found(dev->use_buf_ptr, dev->rx_bufs);
199 
200     return bd;
201 }
202 
203 static ssize_t spapr_vlan_receive(NetClientState *nc, const uint8_t *buf,
204                                   size_t size)
205 {
206     SpaprVioVlan *dev = qemu_get_nic_opaque(nc);
207     SpaprVioDevice *sdev = VIO_SPAPR_DEVICE(dev);
208     vlan_bd_t rxq_bd = vio_ldq(sdev, dev->buf_list + VLAN_RXQ_BD_OFF);
209     vlan_bd_t bd;
210     uint64_t handle;
211     uint8_t control;
212 
213     trace_spapr_vlan_receive(sdev->qdev.id, dev->rx_bufs);
214 
215     if (!dev->isopen) {
216         return -1;
217     }
218 
219     if (!dev->rx_bufs) {
220         spapr_vlan_record_dropped_rx_frame(dev);
221         return 0;
222     }
223 
224     if (dev->compat_flags & SPAPRVLAN_FLAG_RX_BUF_POOLS) {
225         bd = spapr_vlan_get_rx_bd_from_pool(dev, size);
226     } else {
227         bd = spapr_vlan_get_rx_bd_from_page(dev, size);
228     }
229     if (!bd) {
230         spapr_vlan_record_dropped_rx_frame(dev);
231         return 0;
232     }
233 
234     dev->rx_bufs--;
235 
236     /* Transfer the packet data */
237     if (spapr_vio_dma_write(sdev, VLAN_BD_ADDR(bd) + 8, buf, size) < 0) {
238         return -1;
239     }
240 
241     trace_spapr_vlan_receive_dma_completed();
242 
243     /* Update the receive queue */
244     control = VLAN_RXQC_TOGGLE | VLAN_RXQC_VALID;
245     if (rxq_bd & VLAN_BD_TOGGLE) {
246         control ^= VLAN_RXQC_TOGGLE;
247     }
248 
249     handle = vio_ldq(sdev, VLAN_BD_ADDR(bd));
250     vio_stq(sdev, VLAN_BD_ADDR(rxq_bd) + dev->rxq_ptr + 8, handle);
251     vio_stl(sdev, VLAN_BD_ADDR(rxq_bd) + dev->rxq_ptr + 4, size);
252     vio_sth(sdev, VLAN_BD_ADDR(rxq_bd) + dev->rxq_ptr + 2, 8);
253     vio_stb(sdev, VLAN_BD_ADDR(rxq_bd) + dev->rxq_ptr, control);
254 
255     trace_spapr_vlan_receive_wrote(dev->rxq_ptr,
256                                    vio_ldq(sdev, VLAN_BD_ADDR(rxq_bd) +
257                                                  dev->rxq_ptr),
258                                    vio_ldq(sdev, VLAN_BD_ADDR(rxq_bd) +
259                                                  dev->rxq_ptr + 8));
260 
261     dev->rxq_ptr += 16;
262     if (dev->rxq_ptr >= VLAN_BD_LEN(rxq_bd)) {
263         dev->rxq_ptr = 0;
264         vio_stq(sdev, dev->buf_list + VLAN_RXQ_BD_OFF, rxq_bd ^ VLAN_BD_TOGGLE);
265     }
266 
267     if (sdev->signal_state & 1) {
268         spapr_vio_irq_pulse(sdev);
269     }
270 
271     return size;
272 }
273 
274 static NetClientInfo net_spapr_vlan_info = {
275     .type = NET_CLIENT_DRIVER_NIC,
276     .size = sizeof(NICState),
277     .can_receive = spapr_vlan_can_receive,
278     .receive = spapr_vlan_receive,
279 };
280 
281 static void spapr_vlan_flush_rx_queue(void *opaque)
282 {
283     SpaprVioVlan *dev = opaque;
284 
285     qemu_flush_queued_packets(qemu_get_queue(dev->nic));
286 }
287 
288 static void spapr_vlan_reset_rx_pool(RxBufPool *rxp)
289 {
290     /*
291      * Use INT_MAX as bufsize so that unused buffers are moved to the end
292      * of the list during the qsort in spapr_vlan_add_rxbuf_to_pool() later.
293      */
294     rxp->bufsize = INT_MAX;
295     rxp->count = 0;
296     memset(rxp->bds, 0, sizeof(rxp->bds));
297 }
298 
299 static void spapr_vlan_reset(SpaprVioDevice *sdev)
300 {
301     SpaprVioVlan *dev = VIO_SPAPR_VLAN_DEVICE(sdev);
302     int i;
303 
304     dev->buf_list = 0;
305     dev->rx_bufs = 0;
306     dev->isopen = 0;
307 
308     if (dev->compat_flags & SPAPRVLAN_FLAG_RX_BUF_POOLS) {
309         for (i = 0; i < RX_MAX_POOLS; i++) {
310             spapr_vlan_reset_rx_pool(dev->rx_pool[i]);
311         }
312     }
313 
314     memcpy(&dev->nicconf.macaddr.a, &dev->perm_mac.a,
315            sizeof(dev->nicconf.macaddr.a));
316     qemu_format_nic_info_str(qemu_get_queue(dev->nic), dev->nicconf.macaddr.a);
317 }
318 
319 static void spapr_vlan_realize(SpaprVioDevice *sdev, Error **errp)
320 {
321     SpaprVioVlan *dev = VIO_SPAPR_VLAN_DEVICE(sdev);
322 
323     qemu_macaddr_default_if_unset(&dev->nicconf.macaddr);
324 
325     memcpy(&dev->perm_mac.a, &dev->nicconf.macaddr.a, sizeof(dev->perm_mac.a));
326 
327     dev->nic = qemu_new_nic(&net_spapr_vlan_info, &dev->nicconf,
328                             object_get_typename(OBJECT(sdev)), sdev->qdev.id, dev);
329     qemu_format_nic_info_str(qemu_get_queue(dev->nic), dev->nicconf.macaddr.a);
330 
331     dev->rxp_timer = timer_new_us(QEMU_CLOCK_VIRTUAL, spapr_vlan_flush_rx_queue,
332                                   dev);
333 }
334 
335 static void spapr_vlan_instance_init(Object *obj)
336 {
337     SpaprVioVlan *dev = VIO_SPAPR_VLAN_DEVICE(obj);
338     int i;
339 
340     device_add_bootindex_property(obj, &dev->nicconf.bootindex,
341                                   "bootindex", "",
342                                   DEVICE(dev));
343 
344     if (dev->compat_flags & SPAPRVLAN_FLAG_RX_BUF_POOLS) {
345         for (i = 0; i < RX_MAX_POOLS; i++) {
346             dev->rx_pool[i] = g_new(RxBufPool, 1);
347             spapr_vlan_reset_rx_pool(dev->rx_pool[i]);
348         }
349     }
350 }
351 
352 static void spapr_vlan_instance_finalize(Object *obj)
353 {
354     SpaprVioVlan *dev = VIO_SPAPR_VLAN_DEVICE(obj);
355     int i;
356 
357     if (dev->compat_flags & SPAPRVLAN_FLAG_RX_BUF_POOLS) {
358         for (i = 0; i < RX_MAX_POOLS; i++) {
359             g_free(dev->rx_pool[i]);
360             dev->rx_pool[i] = NULL;
361         }
362     }
363 
364     if (dev->rxp_timer) {
365         timer_free(dev->rxp_timer);
366     }
367 }
368 
369 void spapr_vlan_create(SpaprVioBus *bus, NICInfo *nd)
370 {
371     DeviceState *dev;
372 
373     dev = qdev_new("spapr-vlan");
374 
375     qdev_set_nic_properties(dev, nd);
376 
377     qdev_realize_and_unref(dev, &bus->bus, &error_fatal);
378 }
379 
380 static int spapr_vlan_devnode(SpaprVioDevice *dev, void *fdt, int node_off)
381 {
382     SpaprVioVlan *vdev = VIO_SPAPR_VLAN_DEVICE(dev);
383     uint8_t padded_mac[8] = {0, 0};
384     int ret;
385 
386     /* Some old phyp versions give the mac address in an 8-byte
387      * property.  The kernel driver (before 3.10) has an insane workaround;
388      * rather than doing the obvious thing and checking the property
389      * length, it checks whether the first byte has 0b10 in the low
390      * bits.  If a correct 6-byte property has a different first byte
391      * the kernel will get the wrong mac address, overrunning its
392      * buffer in the process (read only, thank goodness).
393      *
394      * Here we return a 6-byte address unless that would break a pre-3.10
395      * driver.  In that case we return a padded 8-byte address to allow the old
396      * workaround to succeed. */
397     if ((vdev->nicconf.macaddr.a[0] & 0x3) == 0x2) {
398         ret = fdt_setprop(fdt, node_off, "local-mac-address",
399                           &vdev->nicconf.macaddr, ETH_ALEN);
400     } else {
401         memcpy(&padded_mac[2], &vdev->nicconf.macaddr, ETH_ALEN);
402         ret = fdt_setprop(fdt, node_off, "local-mac-address",
403                           padded_mac, sizeof(padded_mac));
404     }
405     if (ret < 0) {
406         return ret;
407     }
408 
409     ret = fdt_setprop_cell(fdt, node_off, "ibm,mac-address-filters", 0);
410     if (ret < 0) {
411         return ret;
412     }
413 
414     return 0;
415 }
416 
417 static int check_bd(SpaprVioVlan *dev, vlan_bd_t bd,
418                     target_ulong alignment)
419 {
420     if ((VLAN_BD_ADDR(bd) % alignment)
421         || (VLAN_BD_LEN(bd) % alignment)) {
422         return -1;
423     }
424 
425     if (!spapr_vio_dma_valid(&dev->sdev, VLAN_BD_ADDR(bd),
426                              VLAN_BD_LEN(bd), DMA_DIRECTION_FROM_DEVICE)
427         || !spapr_vio_dma_valid(&dev->sdev, VLAN_BD_ADDR(bd),
428                                 VLAN_BD_LEN(bd), DMA_DIRECTION_TO_DEVICE)) {
429         return -1;
430     }
431 
432     return 0;
433 }
434 
435 static target_ulong h_register_logical_lan(PowerPCCPU *cpu,
436                                            SpaprMachineState *spapr,
437                                            target_ulong opcode,
438                                            target_ulong *args)
439 {
440     target_ulong reg = args[0];
441     target_ulong buf_list = args[1];
442     target_ulong rec_queue = args[2];
443     target_ulong filter_list = args[3];
444     SpaprVioDevice *sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
445     SpaprVioVlan *dev = VIO_SPAPR_VLAN_DEVICE(sdev);
446     vlan_bd_t filter_list_bd;
447 
448     if (!dev) {
449         return H_PARAMETER;
450     }
451 
452     if (dev->isopen) {
453         hcall_dprintf("H_REGISTER_LOGICAL_LAN called twice without "
454                       "H_FREE_LOGICAL_LAN\n");
455         return H_RESOURCE;
456     }
457 
458     if (check_bd(dev, VLAN_VALID_BD(buf_list, SPAPR_TCE_PAGE_SIZE),
459                  SPAPR_TCE_PAGE_SIZE) < 0) {
460         hcall_dprintf("Bad buf_list 0x" TARGET_FMT_lx "\n", buf_list);
461         return H_PARAMETER;
462     }
463 
464     filter_list_bd = VLAN_VALID_BD(filter_list, SPAPR_TCE_PAGE_SIZE);
465     if (check_bd(dev, filter_list_bd, SPAPR_TCE_PAGE_SIZE) < 0) {
466         hcall_dprintf("Bad filter_list 0x" TARGET_FMT_lx "\n", filter_list);
467         return H_PARAMETER;
468     }
469 
470     if (!(rec_queue & VLAN_BD_VALID)
471         || (check_bd(dev, rec_queue, VLAN_RQ_ALIGNMENT) < 0)) {
472         hcall_dprintf("Bad receive queue\n");
473         return H_PARAMETER;
474     }
475 
476     dev->buf_list = buf_list;
477     sdev->signal_state = 0;
478 
479     rec_queue &= ~VLAN_BD_TOGGLE;
480 
481     /* Initialize the buffer list */
482     vio_stq(sdev, buf_list, rec_queue);
483     vio_stq(sdev, buf_list + 8, filter_list_bd);
484     spapr_vio_dma_set(sdev, buf_list + VLAN_RX_BDS_OFF, 0,
485                       SPAPR_TCE_PAGE_SIZE - VLAN_RX_BDS_OFF);
486     dev->add_buf_ptr = VLAN_RX_BDS_OFF - 8;
487     dev->use_buf_ptr = VLAN_RX_BDS_OFF - 8;
488     dev->rx_bufs = 0;
489     dev->rxq_ptr = 0;
490 
491     /* Initialize the receive queue */
492     spapr_vio_dma_set(sdev, VLAN_BD_ADDR(rec_queue), 0, VLAN_BD_LEN(rec_queue));
493 
494     dev->isopen = 1;
495     qemu_flush_queued_packets(qemu_get_queue(dev->nic));
496 
497     return H_SUCCESS;
498 }
499 
500 
501 static target_ulong h_free_logical_lan(PowerPCCPU *cpu,
502                                        SpaprMachineState *spapr,
503                                        target_ulong opcode, target_ulong *args)
504 {
505     target_ulong reg = args[0];
506     SpaprVioDevice *sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
507     SpaprVioVlan *dev = VIO_SPAPR_VLAN_DEVICE(sdev);
508 
509     if (!dev) {
510         return H_PARAMETER;
511     }
512 
513     if (!dev->isopen) {
514         hcall_dprintf("H_FREE_LOGICAL_LAN called without "
515                       "H_REGISTER_LOGICAL_LAN\n");
516         return H_RESOURCE;
517     }
518 
519     spapr_vlan_reset(sdev);
520     return H_SUCCESS;
521 }
522 
523 /**
524  * Used for qsort, this function compares two RxBufPools by size.
525  */
526 static int rx_pool_size_compare(const void *p1, const void *p2)
527 {
528     const RxBufPool *pool1 = *(RxBufPool **)p1;
529     const RxBufPool *pool2 = *(RxBufPool **)p2;
530 
531     if (pool1->bufsize < pool2->bufsize) {
532         return -1;
533     }
534     return pool1->bufsize > pool2->bufsize;
535 }
536 
537 /**
538  * Search for a matching buffer pool with exact matching size,
539  * or return -1 if no matching pool has been found.
540  */
541 static int spapr_vlan_get_rx_pool_id(SpaprVioVlan *dev, int size)
542 {
543     int pool;
544 
545     for (pool = 0; pool < RX_MAX_POOLS; pool++) {
546         if (dev->rx_pool[pool]->bufsize == size) {
547             return pool;
548         }
549     }
550 
551     return -1;
552 }
553 
554 /**
555  * Enqueuing receive buffer by adding it to one of our receive buffer pools
556  */
557 static target_long spapr_vlan_add_rxbuf_to_pool(SpaprVioVlan *dev,
558                                                 target_ulong buf)
559 {
560     int size = VLAN_BD_LEN(buf);
561     int pool;
562 
563     pool = spapr_vlan_get_rx_pool_id(dev, size);
564     if (pool < 0) {
565         /*
566          * No matching pool found? Try to use a new one. If the guest used all
567          * pools before, but changed the size of one pool in the meantime, we might
568          * need to recycle that pool here (if it's empty already). Thus scan
569          * all buffer pools now, starting with the last (likely empty) one.
570          */
571         for (pool = RX_MAX_POOLS - 1; pool >= 0 ; pool--) {
572             if (dev->rx_pool[pool]->count == 0) {
573                 dev->rx_pool[pool]->bufsize = size;
574                 /*
575                  * Sort pools by size so that spapr_vlan_receive()
576                  * can later find the smallest buffer pool easily.
577                  */
578                 qsort(dev->rx_pool, RX_MAX_POOLS, sizeof(dev->rx_pool[0]),
579                       rx_pool_size_compare);
580                 pool = spapr_vlan_get_rx_pool_id(dev, size);
581                 trace_spapr_vlan_add_rxbuf_to_pool_create(pool,
582                                                           VLAN_BD_LEN(buf));
583                 break;
584             }
585         }
586     }
587     /* Still no usable pool? Give up */
588     if (pool < 0 || dev->rx_pool[pool]->count >= RX_POOL_MAX_BDS) {
589         return H_RESOURCE;
590     }
591 
592     trace_spapr_vlan_add_rxbuf_to_pool(pool, VLAN_BD_LEN(buf),
593                                        dev->rx_pool[pool]->count);
594 
595     dev->rx_pool[pool]->bds[dev->rx_pool[pool]->count++] = buf;
596 
597     return 0;
598 }
599 
600 /**
601  * This is the old way of enqueuing receive buffers: Add it to the rx queue
602  * page that has been supplied by the guest (which is quite limited in size).
603  */
604 static target_long spapr_vlan_add_rxbuf_to_page(SpaprVioVlan *dev,
605                                                 target_ulong buf)
606 {
607     vlan_bd_t bd;
608 
609     if (dev->rx_bufs >= VLAN_MAX_BUFS) {
610         return H_RESOURCE;
611     }
612 
613     do {
614         dev->add_buf_ptr += 8;
615         if (dev->add_buf_ptr >= VLAN_RX_BDS_LEN + VLAN_RX_BDS_OFF) {
616             dev->add_buf_ptr = VLAN_RX_BDS_OFF;
617         }
618 
619         bd = vio_ldq(&dev->sdev, dev->buf_list + dev->add_buf_ptr);
620     } while (bd & VLAN_BD_VALID);
621 
622     vio_stq(&dev->sdev, dev->buf_list + dev->add_buf_ptr, buf);
623 
624     trace_spapr_vlan_add_rxbuf_to_page(dev->add_buf_ptr, dev->rx_bufs, buf);
625 
626     return 0;
627 }
628 
629 static target_ulong h_add_logical_lan_buffer(PowerPCCPU *cpu,
630                                              SpaprMachineState *spapr,
631                                              target_ulong opcode,
632                                              target_ulong *args)
633 {
634     target_ulong reg = args[0];
635     target_ulong buf = args[1];
636     SpaprVioDevice *sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
637     SpaprVioVlan *dev = VIO_SPAPR_VLAN_DEVICE(sdev);
638     target_long ret;
639 
640     trace_spapr_vlan_h_add_logical_lan_buffer(reg, buf);
641 
642     if (!sdev) {
643         hcall_dprintf("Bad device\n");
644         return H_PARAMETER;
645     }
646 
647     if ((check_bd(dev, buf, 4) < 0)
648         || (VLAN_BD_LEN(buf) < 16)) {
649         hcall_dprintf("Bad buffer enqueued\n");
650         return H_PARAMETER;
651     }
652 
653     if (!dev->isopen) {
654         return H_RESOURCE;
655     }
656 
657     if (dev->compat_flags & SPAPRVLAN_FLAG_RX_BUF_POOLS) {
658         ret = spapr_vlan_add_rxbuf_to_pool(dev, buf);
659     } else {
660         ret = spapr_vlan_add_rxbuf_to_page(dev, buf);
661     }
662     if (ret) {
663         return ret;
664     }
665 
666     dev->rx_bufs++;
667 
668     /*
669      * Give guest some more time to add additional RX buffers before we
670      * flush the receive queue, so that e.g. fragmented IP packets can
671      * be passed to the guest in one go later (instead of passing single
672      * fragments if there is only one receive buffer available).
673      */
674     timer_mod(dev->rxp_timer, qemu_clock_get_us(QEMU_CLOCK_VIRTUAL) + 500);
675 
676     return H_SUCCESS;
677 }
678 
679 static target_ulong h_send_logical_lan(PowerPCCPU *cpu,
680                                        SpaprMachineState *spapr,
681                                        target_ulong opcode, target_ulong *args)
682 {
683     target_ulong reg = args[0];
684     target_ulong *bufs = args + 1;
685     target_ulong continue_token = args[7];
686     SpaprVioDevice *sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
687     SpaprVioVlan *dev = VIO_SPAPR_VLAN_DEVICE(sdev);
688     unsigned total_len;
689     uint8_t *p;
690     g_autofree uint8_t *lbuf = NULL;
691     int i, nbufs;
692     int ret;
693 
694     trace_spapr_vlan_h_send_logical_lan(reg, continue_token);
695 
696     if (!sdev) {
697         return H_PARAMETER;
698     }
699 
700     trace_spapr_vlan_h_send_logical_lan_rxbufs(dev->rx_bufs);
701 
702     if (!dev->isopen) {
703         return H_DROPPED;
704     }
705 
706     if (continue_token) {
707         return H_HARDWARE; /* FIXME actually handle this */
708     }
709 
710     total_len = 0;
711     for (i = 0; i < 6; i++) {
712         trace_spapr_vlan_h_send_logical_lan_buf_desc(bufs[i]);
713         if (!(bufs[i] & VLAN_BD_VALID)) {
714             break;
715         }
716         total_len += VLAN_BD_LEN(bufs[i]);
717     }
718 
719     nbufs = i;
720     trace_spapr_vlan_h_send_logical_lan_total(nbufs, total_len);
721 
722     if (total_len == 0) {
723         return H_SUCCESS;
724     }
725 
726     if (total_len > MAX_PACKET_SIZE) {
727         /* Don't let the guest force too large an allocation */
728         return H_RESOURCE;
729     }
730 
731     lbuf = g_malloc(total_len);
732     p = lbuf;
733     for (i = 0; i < nbufs; i++) {
734         ret = spapr_vio_dma_read(sdev, VLAN_BD_ADDR(bufs[i]),
735                                  p, VLAN_BD_LEN(bufs[i]));
736         if (ret < 0) {
737             return ret;
738         }
739 
740         p += VLAN_BD_LEN(bufs[i]);
741     }
742 
743     qemu_send_packet(qemu_get_queue(dev->nic), lbuf, total_len);
744 
745     return H_SUCCESS;
746 }
747 
748 static target_ulong h_multicast_ctrl(PowerPCCPU *cpu, SpaprMachineState *spapr,
749                                      target_ulong opcode, target_ulong *args)
750 {
751     target_ulong reg = args[0];
752     SpaprVioDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
753 
754     if (!dev) {
755         return H_PARAMETER;
756     }
757 
758     return H_SUCCESS;
759 }
760 
761 static target_ulong h_change_logical_lan_mac(PowerPCCPU *cpu,
762                                              SpaprMachineState *spapr,
763                                              target_ulong opcode,
764                                              target_ulong *args)
765 {
766     target_ulong reg = args[0];
767     target_ulong macaddr = args[1];
768     SpaprVioDevice *sdev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
769     SpaprVioVlan *dev = VIO_SPAPR_VLAN_DEVICE(sdev);
770     int i;
771 
772     for (i = 0; i < ETH_ALEN; i++) {
773         dev->nicconf.macaddr.a[ETH_ALEN - i - 1] = macaddr & 0xff;
774         macaddr >>= 8;
775     }
776 
777     qemu_format_nic_info_str(qemu_get_queue(dev->nic), dev->nicconf.macaddr.a);
778 
779     return H_SUCCESS;
780 }
781 
782 static Property spapr_vlan_properties[] = {
783     DEFINE_SPAPR_PROPERTIES(SpaprVioVlan, sdev),
784     DEFINE_NIC_PROPERTIES(SpaprVioVlan, nicconf),
785     DEFINE_PROP_BIT("use-rx-buffer-pools", SpaprVioVlan,
786                     compat_flags, SPAPRVLAN_FLAG_RX_BUF_POOLS_BIT, true),
787     DEFINE_PROP_END_OF_LIST(),
788 };
789 
790 static bool spapr_vlan_rx_buffer_pools_needed(void *opaque)
791 {
792     SpaprVioVlan *dev = opaque;
793 
794     return (dev->compat_flags & SPAPRVLAN_FLAG_RX_BUF_POOLS) != 0;
795 }
796 
797 static const VMStateDescription vmstate_rx_buffer_pool = {
798     .name = "spapr_llan/rx_buffer_pool",
799     .version_id = 1,
800     .minimum_version_id = 1,
801     .needed = spapr_vlan_rx_buffer_pools_needed,
802     .fields = (VMStateField[]) {
803         VMSTATE_INT32(bufsize, RxBufPool),
804         VMSTATE_INT32(count, RxBufPool),
805         VMSTATE_UINT64_ARRAY(bds, RxBufPool, RX_POOL_MAX_BDS),
806         VMSTATE_END_OF_LIST()
807     }
808 };
809 
810 static const VMStateDescription vmstate_rx_pools = {
811     .name = "spapr_llan/rx_pools",
812     .version_id = 1,
813     .minimum_version_id = 1,
814     .needed = spapr_vlan_rx_buffer_pools_needed,
815     .fields = (VMStateField[]) {
816         VMSTATE_ARRAY_OF_POINTER_TO_STRUCT(rx_pool, SpaprVioVlan,
817                                            RX_MAX_POOLS, 1,
818                                            vmstate_rx_buffer_pool, RxBufPool),
819         VMSTATE_END_OF_LIST()
820     }
821 };
822 
823 static const VMStateDescription vmstate_spapr_llan = {
824     .name = "spapr_llan",
825     .version_id = 1,
826     .minimum_version_id = 1,
827     .fields = (VMStateField[]) {
828         VMSTATE_SPAPR_VIO(sdev, SpaprVioVlan),
829         /* LLAN state */
830         VMSTATE_BOOL(isopen, SpaprVioVlan),
831         VMSTATE_UINT64(buf_list, SpaprVioVlan),
832         VMSTATE_UINT32(add_buf_ptr, SpaprVioVlan),
833         VMSTATE_UINT32(use_buf_ptr, SpaprVioVlan),
834         VMSTATE_UINT32(rx_bufs, SpaprVioVlan),
835         VMSTATE_UINT64(rxq_ptr, SpaprVioVlan),
836 
837         VMSTATE_END_OF_LIST()
838     },
839     .subsections = (const VMStateDescription * []) {
840         &vmstate_rx_pools,
841         NULL
842     }
843 };
844 
845 static void spapr_vlan_class_init(ObjectClass *klass, void *data)
846 {
847     DeviceClass *dc = DEVICE_CLASS(klass);
848     SpaprVioDeviceClass *k = VIO_SPAPR_DEVICE_CLASS(klass);
849 
850     k->realize = spapr_vlan_realize;
851     k->reset = spapr_vlan_reset;
852     k->devnode = spapr_vlan_devnode;
853     k->dt_name = "l-lan";
854     k->dt_type = "network";
855     k->dt_compatible = "IBM,l-lan";
856     k->signal_mask = 0x1;
857     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
858     device_class_set_props(dc, spapr_vlan_properties);
859     k->rtce_window_size = 0x10000000;
860     dc->vmsd = &vmstate_spapr_llan;
861 }
862 
863 static const TypeInfo spapr_vlan_info = {
864     .name          = TYPE_VIO_SPAPR_VLAN_DEVICE,
865     .parent        = TYPE_VIO_SPAPR_DEVICE,
866     .instance_size = sizeof(SpaprVioVlan),
867     .class_init    = spapr_vlan_class_init,
868     .instance_init = spapr_vlan_instance_init,
869     .instance_finalize = spapr_vlan_instance_finalize,
870 };
871 
872 static void spapr_vlan_register_types(void)
873 {
874     spapr_register_hypercall(H_REGISTER_LOGICAL_LAN, h_register_logical_lan);
875     spapr_register_hypercall(H_FREE_LOGICAL_LAN, h_free_logical_lan);
876     spapr_register_hypercall(H_SEND_LOGICAL_LAN, h_send_logical_lan);
877     spapr_register_hypercall(H_ADD_LOGICAL_LAN_BUFFER,
878                              h_add_logical_lan_buffer);
879     spapr_register_hypercall(H_MULTICAST_CTRL, h_multicast_ctrl);
880     spapr_register_hypercall(H_CHANGE_LOGICAL_LAN_MAC,
881                              h_change_logical_lan_mac);
882     type_register_static(&spapr_vlan_info);
883 }
884 
885 type_init(spapr_vlan_register_types)
886