xref: /dpdk/drivers/net/virtio/virtqueue.h (revision a49342abbb5d68fafab1d2ba4c669c0e76e32c65)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
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10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #ifndef _VIRTQUEUE_H_
35 #define _VIRTQUEUE_H_
36 
37 #include <stdint.h>
38 
39 #include <rte_atomic.h>
40 #include <rte_memory.h>
41 #include <rte_memzone.h>
42 #include <rte_mempool.h>
43 
44 #include "virtio_pci.h"
45 #include "virtio_ring.h"
46 #include "virtio_logs.h"
47 #include "virtio_rxtx.h"
48 
49 struct rte_mbuf;
50 
51 /*
52  * Per virtio_config.h in Linux.
53  *     For virtio_pci on SMP, we don't need to order with respect to MMIO
54  *     accesses through relaxed memory I/O windows, so smp_mb() et al are
55  *     sufficient.
56  *
57  */
58 #define virtio_mb()	rte_smp_mb()
59 #define virtio_rmb()	rte_smp_rmb()
60 #define virtio_wmb()	rte_smp_wmb()
61 
62 #ifdef RTE_PMD_PACKET_PREFETCH
63 #define rte_packet_prefetch(p)  rte_prefetch1(p)
64 #else
65 #define rte_packet_prefetch(p)  do {} while(0)
66 #endif
67 
68 #define VIRTQUEUE_MAX_NAME_SZ 32
69 
70 #ifdef RTE_VIRTIO_USER
71 /**
72  * Return the physical address (or virtual address in case of
73  * virtio-user) of mbuf data buffer.
74  */
75 #define VIRTIO_MBUF_ADDR(mb, vq) (*(uint64_t *)((uintptr_t)(mb) + (vq)->offset))
76 #else
77 #define VIRTIO_MBUF_ADDR(mb, vq) ((mb)->buf_physaddr)
78 #endif
79 
80 /**
81  * Return the physical address (or virtual address in case of
82  * virtio-user) of mbuf data buffer, taking care of mbuf data offset
83  */
84 #define VIRTIO_MBUF_DATA_DMA_ADDR(mb, vq) \
85 	(VIRTIO_MBUF_ADDR(mb, vq) + (mb)->data_off)
86 
87 #define VTNET_SQ_RQ_QUEUE_IDX 0
88 #define VTNET_SQ_TQ_QUEUE_IDX 1
89 #define VTNET_SQ_CQ_QUEUE_IDX 2
90 
91 enum { VTNET_RQ = 0, VTNET_TQ = 1, VTNET_CQ = 2 };
92 /**
93  * The maximum virtqueue size is 2^15. Use that value as the end of
94  * descriptor chain terminator since it will never be a valid index
95  * in the descriptor table. This is used to verify we are correctly
96  * handling vq_free_cnt.
97  */
98 #define VQ_RING_DESC_CHAIN_END 32768
99 
100 /**
101  * Control the RX mode, ie. promiscuous, allmulti, etc...
102  * All commands require an "out" sg entry containing a 1 byte
103  * state value, zero = disable, non-zero = enable.  Commands
104  * 0 and 1 are supported with the VIRTIO_NET_F_CTRL_RX feature.
105  * Commands 2-5 are added with VIRTIO_NET_F_CTRL_RX_EXTRA.
106  */
107 #define VIRTIO_NET_CTRL_RX              0
108 #define VIRTIO_NET_CTRL_RX_PROMISC      0
109 #define VIRTIO_NET_CTRL_RX_ALLMULTI     1
110 #define VIRTIO_NET_CTRL_RX_ALLUNI       2
111 #define VIRTIO_NET_CTRL_RX_NOMULTI      3
112 #define VIRTIO_NET_CTRL_RX_NOUNI        4
113 #define VIRTIO_NET_CTRL_RX_NOBCAST      5
114 
115 /**
116  * Control the MAC
117  *
118  * The MAC filter table is managed by the hypervisor, the guest should
119  * assume the size is infinite.  Filtering should be considered
120  * non-perfect, ie. based on hypervisor resources, the guest may
121  * received packets from sources not specified in the filter list.
122  *
123  * In addition to the class/cmd header, the TABLE_SET command requires
124  * two out scatterlists.  Each contains a 4 byte count of entries followed
125  * by a concatenated byte stream of the ETH_ALEN MAC addresses.  The
126  * first sg list contains unicast addresses, the second is for multicast.
127  * This functionality is present if the VIRTIO_NET_F_CTRL_RX feature
128  * is available.
129  *
130  * The ADDR_SET command requests one out scatterlist, it contains a
131  * 6 bytes MAC address. This functionality is present if the
132  * VIRTIO_NET_F_CTRL_MAC_ADDR feature is available.
133  */
134 struct virtio_net_ctrl_mac {
135 	uint32_t entries;
136 	uint8_t macs[][ETHER_ADDR_LEN];
137 } __attribute__((__packed__));
138 
139 #define VIRTIO_NET_CTRL_MAC    1
140  #define VIRTIO_NET_CTRL_MAC_TABLE_SET        0
141  #define VIRTIO_NET_CTRL_MAC_ADDR_SET         1
142 
143 /**
144  * Control VLAN filtering
145  *
146  * The VLAN filter table is controlled via a simple ADD/DEL interface.
147  * VLAN IDs not added may be filtered by the hypervisor.  Del is the
148  * opposite of add.  Both commands expect an out entry containing a 2
149  * byte VLAN ID.  VLAN filtering is available with the
150  * VIRTIO_NET_F_CTRL_VLAN feature bit.
151  */
152 #define VIRTIO_NET_CTRL_VLAN     2
153 #define VIRTIO_NET_CTRL_VLAN_ADD 0
154 #define VIRTIO_NET_CTRL_VLAN_DEL 1
155 
156 struct virtio_net_ctrl_hdr {
157 	uint8_t class;
158 	uint8_t cmd;
159 } __attribute__((packed));
160 
161 typedef uint8_t virtio_net_ctrl_ack;
162 
163 #define VIRTIO_NET_OK     0
164 #define VIRTIO_NET_ERR    1
165 
166 #define VIRTIO_MAX_CTRL_DATA 2048
167 
168 struct virtio_pmd_ctrl {
169 	struct virtio_net_ctrl_hdr hdr;
170 	virtio_net_ctrl_ack status;
171 	uint8_t data[VIRTIO_MAX_CTRL_DATA];
172 };
173 
174 struct vq_desc_extra {
175 	void *cookie;
176 	uint16_t ndescs;
177 };
178 
179 struct virtqueue {
180 	struct virtio_hw  *hw; /**< virtio_hw structure pointer. */
181 	struct vring vq_ring;  /**< vring keeping desc, used and avail */
182 	/**
183 	 * Last consumed descriptor in the used table,
184 	 * trails vq_ring.used->idx.
185 	 */
186 	uint16_t vq_used_cons_idx;
187 	uint16_t vq_nentries;  /**< vring desc numbers */
188 	uint16_t vq_free_cnt;  /**< num of desc available */
189 	uint16_t vq_avail_idx; /**< sync until needed */
190 	uint16_t vq_free_thresh; /**< free threshold */
191 
192 	void *vq_ring_virt_mem;  /**< linear address of vring*/
193 	unsigned int vq_ring_size;
194 
195 	union {
196 		struct virtnet_rx rxq;
197 		struct virtnet_tx txq;
198 		struct virtnet_ctl cq;
199 	};
200 
201 	phys_addr_t vq_ring_mem; /**< physical address of vring,
202 				  * or virtual address for virtio_user. */
203 
204 	/**
205 	 * Head of the free chain in the descriptor table. If
206 	 * there are no free descriptors, this will be set to
207 	 * VQ_RING_DESC_CHAIN_END.
208 	 */
209 	uint16_t  vq_desc_head_idx;
210 	uint16_t  vq_desc_tail_idx;
211 	uint16_t  vq_queue_index;   /**< PCI queue index */
212 	uint16_t offset; /**< relative offset to obtain addr in mbuf */
213 	uint16_t  *notify_addr;
214 	struct rte_mbuf **sw_ring;  /**< RX software ring. */
215 	struct vq_desc_extra vq_descx[0];
216 };
217 
218 /* If multiqueue is provided by host, then we suppport it. */
219 #define VIRTIO_NET_CTRL_MQ   4
220 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET        0
221 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN        1
222 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX        0x8000
223 
224 #define VIRTIO_NET_CTRL_MAC_ADDR_SET         1
225 
226 /**
227  * This is the first element of the scatter-gather list.  If you don't
228  * specify GSO or CSUM features, you can simply ignore the header.
229  */
230 struct virtio_net_hdr {
231 #define VIRTIO_NET_HDR_F_NEEDS_CSUM 1    /**< Use csum_start,csum_offset*/
232 #define VIRTIO_NET_HDR_F_DATA_VALID 2    /**< Checksum is valid */
233 	uint8_t flags;
234 #define VIRTIO_NET_HDR_GSO_NONE     0    /**< Not a GSO frame */
235 #define VIRTIO_NET_HDR_GSO_TCPV4    1    /**< GSO frame, IPv4 TCP (TSO) */
236 #define VIRTIO_NET_HDR_GSO_UDP      3    /**< GSO frame, IPv4 UDP (UFO) */
237 #define VIRTIO_NET_HDR_GSO_TCPV6    4    /**< GSO frame, IPv6 TCP */
238 #define VIRTIO_NET_HDR_GSO_ECN      0x80 /**< TCP has ECN set */
239 	uint8_t gso_type;
240 	uint16_t hdr_len;     /**< Ethernet + IP + tcp/udp hdrs */
241 	uint16_t gso_size;    /**< Bytes to append to hdr_len per frame */
242 	uint16_t csum_start;  /**< Position to start checksumming from */
243 	uint16_t csum_offset; /**< Offset after that to place checksum */
244 };
245 
246 /**
247  * This is the version of the header to use when the MRG_RXBUF
248  * feature has been negotiated.
249  */
250 struct virtio_net_hdr_mrg_rxbuf {
251 	struct   virtio_net_hdr hdr;
252 	uint16_t num_buffers; /**< Number of merged rx buffers */
253 };
254 
255 /* Region reserved to allow for transmit header and indirect ring */
256 #define VIRTIO_MAX_TX_INDIRECT 8
257 struct virtio_tx_region {
258 	struct virtio_net_hdr_mrg_rxbuf tx_hdr;
259 	struct vring_desc tx_indir[VIRTIO_MAX_TX_INDIRECT]
260 			   __attribute__((__aligned__(16)));
261 };
262 
263 /* Chain all the descriptors in the ring with an END */
264 static inline void
265 vring_desc_init(struct vring_desc *dp, uint16_t n)
266 {
267 	uint16_t i;
268 
269 	for (i = 0; i < n - 1; i++)
270 		dp[i].next = (uint16_t)(i + 1);
271 	dp[i].next = VQ_RING_DESC_CHAIN_END;
272 }
273 
274 /**
275  * Tell the backend not to interrupt us.
276  */
277 void virtqueue_disable_intr(struct virtqueue *vq);
278 /**
279  *  Dump virtqueue internal structures, for debug purpose only.
280  */
281 void virtqueue_dump(struct virtqueue *vq);
282 /**
283  *  Get all mbufs to be freed.
284  */
285 struct rte_mbuf *virtqueue_detatch_unused(struct virtqueue *vq);
286 
287 static inline int
288 virtqueue_full(const struct virtqueue *vq)
289 {
290 	return vq->vq_free_cnt == 0;
291 }
292 
293 #define VIRTQUEUE_NUSED(vq) ((uint16_t)((vq)->vq_ring.used->idx - (vq)->vq_used_cons_idx))
294 
295 static inline void
296 vq_update_avail_idx(struct virtqueue *vq)
297 {
298 	virtio_wmb();
299 	vq->vq_ring.avail->idx = vq->vq_avail_idx;
300 }
301 
302 static inline void
303 vq_update_avail_ring(struct virtqueue *vq, uint16_t desc_idx)
304 {
305 	uint16_t avail_idx;
306 	/*
307 	 * Place the head of the descriptor chain into the next slot and make
308 	 * it usable to the host. The chain is made available now rather than
309 	 * deferring to virtqueue_notify() in the hopes that if the host is
310 	 * currently running on another CPU, we can keep it processing the new
311 	 * descriptor.
312 	 */
313 	avail_idx = (uint16_t)(vq->vq_avail_idx & (vq->vq_nentries - 1));
314 	if (unlikely(vq->vq_ring.avail->ring[avail_idx] != desc_idx))
315 		vq->vq_ring.avail->ring[avail_idx] = desc_idx;
316 	vq->vq_avail_idx++;
317 }
318 
319 static inline int
320 virtqueue_kick_prepare(struct virtqueue *vq)
321 {
322 	return !(vq->vq_ring.used->flags & VRING_USED_F_NO_NOTIFY);
323 }
324 
325 static inline void
326 virtqueue_notify(struct virtqueue *vq)
327 {
328 	/*
329 	 * Ensure updated avail->idx is visible to host.
330 	 * For virtio on IA, the notificaiton is through io port operation
331 	 * which is a serialization instruction itself.
332 	 */
333 	vq->hw->vtpci_ops->notify_queue(vq->hw, vq);
334 }
335 
336 #ifdef RTE_LIBRTE_VIRTIO_DEBUG_DUMP
337 #define VIRTQUEUE_DUMP(vq) do { \
338 	uint16_t used_idx, nused; \
339 	used_idx = (vq)->vq_ring.used->idx; \
340 	nused = (uint16_t)(used_idx - (vq)->vq_used_cons_idx); \
341 	PMD_INIT_LOG(DEBUG, \
342 	  "VQ: - size=%d; free=%d; used=%d; desc_head_idx=%d;" \
343 	  " avail.idx=%d; used_cons_idx=%d; used.idx=%d;" \
344 	  " avail.flags=0x%x; used.flags=0x%x", \
345 	  (vq)->vq_nentries, (vq)->vq_free_cnt, nused, \
346 	  (vq)->vq_desc_head_idx, (vq)->vq_ring.avail->idx, \
347 	  (vq)->vq_used_cons_idx, (vq)->vq_ring.used->idx, \
348 	  (vq)->vq_ring.avail->flags, (vq)->vq_ring.used->flags); \
349 } while (0)
350 #else
351 #define VIRTQUEUE_DUMP(vq) do { } while (0)
352 #endif
353 
354 #endif /* _VIRTQUEUE_H_ */
355