xref: /dpdk/drivers/net/virtio/virtqueue.h (revision ebee5594a35e2af743ff03cde7d4bac67ac772f2)
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
8  *   modification, are permitted provided that the following conditions
9  *   are met:
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
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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 
48 struct rte_mbuf;
49 
50 /*
51  * Per virtio_config.h in Linux.
52  *     For virtio_pci on SMP, we don't need to order with respect to MMIO
53  *     accesses through relaxed memory I/O windows, so smp_mb() et al are
54  *     sufficient.
55  *
56  */
57 #define virtio_mb()	rte_smp_mb()
58 #define virtio_rmb()	rte_smp_rmb()
59 #define virtio_wmb()	rte_smp_wmb()
60 
61 #ifdef RTE_PMD_PACKET_PREFETCH
62 #define rte_packet_prefetch(p)  rte_prefetch1(p)
63 #else
64 #define rte_packet_prefetch(p)  do {} while(0)
65 #endif
66 
67 #define VIRTQUEUE_MAX_NAME_SZ 32
68 
69 #ifdef RTE_VIRTIO_USER
70 #define MBUF_DATA_DMA_ADDR(mb, offset) \
71 	((uint64_t)((uintptr_t)(*(void **)((uintptr_t)mb + offset)) \
72 			+ (mb)->data_off))
73 #else /* RTE_VIRTIO_USER */
74 #define MBUF_DATA_DMA_ADDR(mb, offset) rte_mbuf_data_dma_addr(mb)
75 #endif /* RTE_VIRTIO_USER */
76 
77 #define VTNET_SQ_RQ_QUEUE_IDX 0
78 #define VTNET_SQ_TQ_QUEUE_IDX 1
79 #define VTNET_SQ_CQ_QUEUE_IDX 2
80 
81 enum { VTNET_RQ = 0, VTNET_TQ = 1, VTNET_CQ = 2 };
82 /**
83  * The maximum virtqueue size is 2^15. Use that value as the end of
84  * descriptor chain terminator since it will never be a valid index
85  * in the descriptor table. This is used to verify we are correctly
86  * handling vq_free_cnt.
87  */
88 #define VQ_RING_DESC_CHAIN_END 32768
89 
90 /**
91  * Control the RX mode, ie. promiscuous, allmulti, etc...
92  * All commands require an "out" sg entry containing a 1 byte
93  * state value, zero = disable, non-zero = enable.  Commands
94  * 0 and 1 are supported with the VIRTIO_NET_F_CTRL_RX feature.
95  * Commands 2-5 are added with VIRTIO_NET_F_CTRL_RX_EXTRA.
96  */
97 #define VIRTIO_NET_CTRL_RX              0
98 #define VIRTIO_NET_CTRL_RX_PROMISC      0
99 #define VIRTIO_NET_CTRL_RX_ALLMULTI     1
100 #define VIRTIO_NET_CTRL_RX_ALLUNI       2
101 #define VIRTIO_NET_CTRL_RX_NOMULTI      3
102 #define VIRTIO_NET_CTRL_RX_NOUNI        4
103 #define VIRTIO_NET_CTRL_RX_NOBCAST      5
104 
105 /**
106  * Control the MAC
107  *
108  * The MAC filter table is managed by the hypervisor, the guest should
109  * assume the size is infinite.  Filtering should be considered
110  * non-perfect, ie. based on hypervisor resources, the guest may
111  * received packets from sources not specified in the filter list.
112  *
113  * In addition to the class/cmd header, the TABLE_SET command requires
114  * two out scatterlists.  Each contains a 4 byte count of entries followed
115  * by a concatenated byte stream of the ETH_ALEN MAC addresses.  The
116  * first sg list contains unicast addresses, the second is for multicast.
117  * This functionality is present if the VIRTIO_NET_F_CTRL_RX feature
118  * is available.
119  *
120  * The ADDR_SET command requests one out scatterlist, it contains a
121  * 6 bytes MAC address. This functionality is present if the
122  * VIRTIO_NET_F_CTRL_MAC_ADDR feature is available.
123  */
124 struct virtio_net_ctrl_mac {
125 	uint32_t entries;
126 	uint8_t macs[][ETHER_ADDR_LEN];
127 } __attribute__((__packed__));
128 
129 #define VIRTIO_NET_CTRL_MAC    1
130  #define VIRTIO_NET_CTRL_MAC_TABLE_SET        0
131  #define VIRTIO_NET_CTRL_MAC_ADDR_SET         1
132 
133 /**
134  * Control VLAN filtering
135  *
136  * The VLAN filter table is controlled via a simple ADD/DEL interface.
137  * VLAN IDs not added may be filtered by the hypervisor.  Del is the
138  * opposite of add.  Both commands expect an out entry containing a 2
139  * byte VLAN ID.  VLAN filtering is available with the
140  * VIRTIO_NET_F_CTRL_VLAN feature bit.
141  */
142 #define VIRTIO_NET_CTRL_VLAN     2
143 #define VIRTIO_NET_CTRL_VLAN_ADD 0
144 #define VIRTIO_NET_CTRL_VLAN_DEL 1
145 
146 struct virtio_net_ctrl_hdr {
147 	uint8_t class;
148 	uint8_t cmd;
149 } __attribute__((packed));
150 
151 typedef uint8_t virtio_net_ctrl_ack;
152 
153 #define VIRTIO_NET_OK     0
154 #define VIRTIO_NET_ERR    1
155 
156 #define VIRTIO_MAX_CTRL_DATA 2048
157 
158 struct virtio_pmd_ctrl {
159 	struct virtio_net_ctrl_hdr hdr;
160 	virtio_net_ctrl_ack status;
161 	uint8_t data[VIRTIO_MAX_CTRL_DATA];
162 };
163 
164 struct vq_desc_extra {
165 	void *cookie;
166 	uint16_t ndescs;
167 };
168 
169 struct virtqueue {
170 	struct virtio_hw  *hw; /**< virtio_hw structure pointer. */
171 	struct vring vq_ring;  /**< vring keeping desc, used and avail */
172 	/**
173 	 * Last consumed descriptor in the used table,
174 	 * trails vq_ring.used->idx.
175 	 */
176 	uint16_t vq_used_cons_idx;
177 	uint16_t vq_nentries;  /**< vring desc numbers */
178 	uint16_t vq_free_cnt;  /**< num of desc available */
179 	uint16_t vq_avail_idx; /**< sync until needed */
180 	uint16_t vq_free_thresh; /**< free threshold */
181 
182 	void *vq_ring_virt_mem;  /**< linear address of vring*/
183 	unsigned int vq_ring_size;
184 
185 	phys_addr_t vq_ring_mem; /**< physical address of vring */
186 				/**< use virtual address for virtio-user. */
187 
188 	/**
189 	 * Head of the free chain in the descriptor table. If
190 	 * there are no free descriptors, this will be set to
191 	 * VQ_RING_DESC_CHAIN_END.
192 	 */
193 	uint16_t  vq_desc_head_idx;
194 	uint16_t  vq_desc_tail_idx;
195 	uint16_t  vq_queue_index;   /**< PCI queue index */
196 	uint16_t offset; /**< relative offset to obtain addr in mbuf */
197 	uint16_t  *notify_addr;
198 	int configured;
199 	struct rte_mbuf **sw_ring;  /**< RX software ring. */
200 	struct vq_desc_extra vq_descx[0];
201 };
202 
203 /* If multiqueue is provided by host, then we suppport it. */
204 #define VIRTIO_NET_CTRL_MQ   4
205 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET        0
206 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN        1
207 #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX        0x8000
208 
209 #define VIRTIO_NET_CTRL_MAC_ADDR_SET         1
210 
211 /**
212  * This is the first element of the scatter-gather list.  If you don't
213  * specify GSO or CSUM features, you can simply ignore the header.
214  */
215 struct virtio_net_hdr {
216 #define VIRTIO_NET_HDR_F_NEEDS_CSUM 1    /**< Use csum_start,csum_offset*/
217 	uint8_t flags;
218 #define VIRTIO_NET_HDR_GSO_NONE     0    /**< Not a GSO frame */
219 #define VIRTIO_NET_HDR_GSO_TCPV4    1    /**< GSO frame, IPv4 TCP (TSO) */
220 #define VIRTIO_NET_HDR_GSO_UDP      3    /**< GSO frame, IPv4 UDP (UFO) */
221 #define VIRTIO_NET_HDR_GSO_TCPV6    4    /**< GSO frame, IPv6 TCP */
222 #define VIRTIO_NET_HDR_GSO_ECN      0x80 /**< TCP has ECN set */
223 	uint8_t gso_type;
224 	uint16_t hdr_len;     /**< Ethernet + IP + tcp/udp hdrs */
225 	uint16_t gso_size;    /**< Bytes to append to hdr_len per frame */
226 	uint16_t csum_start;  /**< Position to start checksumming from */
227 	uint16_t csum_offset; /**< Offset after that to place checksum */
228 };
229 
230 /**
231  * This is the version of the header to use when the MRG_RXBUF
232  * feature has been negotiated.
233  */
234 struct virtio_net_hdr_mrg_rxbuf {
235 	struct   virtio_net_hdr hdr;
236 	uint16_t num_buffers; /**< Number of merged rx buffers */
237 };
238 
239 /* Region reserved to allow for transmit header and indirect ring */
240 #define VIRTIO_MAX_TX_INDIRECT 8
241 struct virtio_tx_region {
242 	struct virtio_net_hdr_mrg_rxbuf tx_hdr;
243 	struct vring_desc tx_indir[VIRTIO_MAX_TX_INDIRECT]
244 			   __attribute__((__aligned__(16)));
245 };
246 
247 /* Chain all the descriptors in the ring with an END */
248 static inline void
249 vring_desc_init(struct vring_desc *dp, uint16_t n)
250 {
251 	uint16_t i;
252 
253 	for (i = 0; i < n - 1; i++)
254 		dp[i].next = (uint16_t)(i + 1);
255 	dp[i].next = VQ_RING_DESC_CHAIN_END;
256 }
257 
258 /**
259  * Tell the backend not to interrupt us.
260  */
261 void virtqueue_disable_intr(struct virtqueue *vq);
262 /**
263  *  Dump virtqueue internal structures, for debug purpose only.
264  */
265 void virtqueue_dump(struct virtqueue *vq);
266 /**
267  *  Get all mbufs to be freed.
268  */
269 struct rte_mbuf *virtqueue_detatch_unused(struct virtqueue *vq);
270 
271 static inline int
272 virtqueue_full(const struct virtqueue *vq)
273 {
274 	return vq->vq_free_cnt == 0;
275 }
276 
277 #define VIRTQUEUE_NUSED(vq) ((uint16_t)((vq)->vq_ring.used->idx - (vq)->vq_used_cons_idx))
278 
279 static inline void
280 vq_update_avail_idx(struct virtqueue *vq)
281 {
282 	virtio_wmb();
283 	vq->vq_ring.avail->idx = vq->vq_avail_idx;
284 }
285 
286 static inline void
287 vq_update_avail_ring(struct virtqueue *vq, uint16_t desc_idx)
288 {
289 	uint16_t avail_idx;
290 	/*
291 	 * Place the head of the descriptor chain into the next slot and make
292 	 * it usable to the host. The chain is made available now rather than
293 	 * deferring to virtqueue_notify() in the hopes that if the host is
294 	 * currently running on another CPU, we can keep it processing the new
295 	 * descriptor.
296 	 */
297 	avail_idx = (uint16_t)(vq->vq_avail_idx & (vq->vq_nentries - 1));
298 	if (unlikely(vq->vq_ring.avail->ring[avail_idx] != desc_idx))
299 		vq->vq_ring.avail->ring[avail_idx] = desc_idx;
300 	vq->vq_avail_idx++;
301 }
302 
303 static inline int
304 virtqueue_kick_prepare(struct virtqueue *vq)
305 {
306 	return !(vq->vq_ring.used->flags & VRING_USED_F_NO_NOTIFY);
307 }
308 
309 static inline void
310 virtqueue_notify(struct virtqueue *vq)
311 {
312 	/*
313 	 * Ensure updated avail->idx is visible to host.
314 	 * For virtio on IA, the notificaiton is through io port operation
315 	 * which is a serialization instruction itself.
316 	 */
317 	vq->hw->vtpci_ops->notify_queue(vq->hw, vq);
318 }
319 
320 #ifdef RTE_LIBRTE_VIRTIO_DEBUG_DUMP
321 #define VIRTQUEUE_DUMP(vq) do { \
322 	uint16_t used_idx, nused; \
323 	used_idx = (vq)->vq_ring.used->idx; \
324 	nused = (uint16_t)(used_idx - (vq)->vq_used_cons_idx); \
325 	PMD_INIT_LOG(DEBUG, \
326 	  "VQ: - size=%d; free=%d; used=%d; desc_head_idx=%d;" \
327 	  " avail.idx=%d; used_cons_idx=%d; used.idx=%d;" \
328 	  " avail.flags=0x%x; used.flags=0x%x", \
329 	  (vq)->vq_nentries, (vq)->vq_free_cnt, nused, \
330 	  (vq)->vq_desc_head_idx, (vq)->vq_ring.avail->idx, \
331 	  (vq)->vq_used_cons_idx, (vq)->vq_ring.used->idx, \
332 	  (vq)->vq_ring.avail->flags, (vq)->vq_ring.used->flags); \
333 } while (0)
334 #else
335 #define VIRTQUEUE_DUMP(vq) do { } while (0)
336 #endif
337 
338 #endif /* _VIRTQUEUE_H_ */
339