1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2018, Intel Corporation. */
3
4 #include "ice_common.h"
5 #include "ice_vf_mbx.h"
6
7 /**
8 * ice_aq_send_msg_to_vf
9 * @hw: pointer to the hardware structure
10 * @vfid: VF ID to send msg
11 * @v_opcode: opcodes for VF-PF communication
12 * @v_retval: return error code
13 * @msg: pointer to the msg buffer
14 * @msglen: msg length
15 * @cd: pointer to command details
16 *
17 * Send message to VF driver (0x0802) using mailbox
18 * queue and asynchronously sending message via
19 * ice_sq_send_cmd() function
20 */
21 int
ice_aq_send_msg_to_vf(struct ice_hw * hw,u16 vfid,u32 v_opcode,u32 v_retval,u8 * msg,u16 msglen,struct ice_sq_cd * cd)22 ice_aq_send_msg_to_vf(struct ice_hw *hw, u16 vfid, u32 v_opcode, u32 v_retval,
23 u8 *msg, u16 msglen, struct ice_sq_cd *cd)
24 {
25 struct ice_aqc_pf_vf_msg *cmd;
26 struct ice_aq_desc desc;
27
28 ice_fill_dflt_direct_cmd_desc(&desc, ice_mbx_opc_send_msg_to_vf);
29
30 cmd = &desc.params.virt;
31 cmd->id = cpu_to_le32(vfid);
32
33 desc.cookie_high = cpu_to_le32(v_opcode);
34 desc.cookie_low = cpu_to_le32(v_retval);
35
36 if (msglen)
37 desc.flags |= cpu_to_le16(ICE_AQ_FLAG_RD);
38
39 return ice_sq_send_cmd(hw, &hw->mailboxq, &desc, msg, msglen, cd);
40 }
41
42 static const u32 ice_legacy_aq_to_vc_speed[] = {
43 VIRTCHNL_LINK_SPEED_100MB, /* BIT(0) */
44 VIRTCHNL_LINK_SPEED_100MB,
45 VIRTCHNL_LINK_SPEED_1GB,
46 VIRTCHNL_LINK_SPEED_1GB,
47 VIRTCHNL_LINK_SPEED_1GB,
48 VIRTCHNL_LINK_SPEED_10GB,
49 VIRTCHNL_LINK_SPEED_20GB,
50 VIRTCHNL_LINK_SPEED_25GB,
51 VIRTCHNL_LINK_SPEED_40GB,
52 VIRTCHNL_LINK_SPEED_40GB,
53 VIRTCHNL_LINK_SPEED_40GB,
54 };
55
56 /**
57 * ice_conv_link_speed_to_virtchnl
58 * @adv_link_support: determines the format of the returned link speed
59 * @link_speed: variable containing the link_speed to be converted
60 *
61 * Convert link speed supported by HW to link speed supported by virtchnl.
62 * If adv_link_support is true, then return link speed in Mbps. Else return
63 * link speed as a VIRTCHNL_LINK_SPEED_* casted to a u32. Note that the caller
64 * needs to cast back to an enum virtchnl_link_speed in the case where
65 * adv_link_support is false, but when adv_link_support is true the caller can
66 * expect the speed in Mbps.
67 */
ice_conv_link_speed_to_virtchnl(bool adv_link_support,u16 link_speed)68 u32 ice_conv_link_speed_to_virtchnl(bool adv_link_support, u16 link_speed)
69 {
70 /* convert a BIT() value into an array index */
71 u32 index = fls(link_speed) - 1;
72
73 if (adv_link_support)
74 return ice_get_link_speed(index);
75 else if (index < ARRAY_SIZE(ice_legacy_aq_to_vc_speed))
76 /* Virtchnl speeds are not defined for every speed supported in
77 * the hardware. To maintain compatibility with older AVF
78 * drivers, while reporting the speed the new speed values are
79 * resolved to the closest known virtchnl speeds
80 */
81 return ice_legacy_aq_to_vc_speed[index];
82
83 return VIRTCHNL_LINK_SPEED_UNKNOWN;
84 }
85
86 /* The mailbox overflow detection algorithm helps to check if there
87 * is a possibility of a malicious VF transmitting too many MBX messages to the
88 * PF.
89 * 1. The mailbox snapshot structure, ice_mbx_snapshot, is initialized during
90 * driver initialization in ice_init_hw() using ice_mbx_init_snapshot().
91 * The struct ice_mbx_snapshot helps to track and traverse a static window of
92 * messages within the mailbox queue while looking for a malicious VF.
93 *
94 * 2. When the caller starts processing its mailbox queue in response to an
95 * interrupt, the structure ice_mbx_snapshot is expected to be cleared before
96 * the algorithm can be run for the first time for that interrupt. This
97 * requires calling ice_mbx_reset_snapshot() as well as calling
98 * ice_mbx_reset_vf_info() for each VF tracking structure.
99 *
100 * 3. For every message read by the caller from the MBX Queue, the caller must
101 * call the detection algorithm's entry function ice_mbx_vf_state_handler().
102 * Before every call to ice_mbx_vf_state_handler() the struct ice_mbx_data is
103 * filled as it is required to be passed to the algorithm.
104 *
105 * 4. Every time a message is read from the MBX queue, a tracking structure
106 * for the VF must be passed to the state handler. The boolean output
107 * report_malvf from ice_mbx_vf_state_handler() serves as an indicator to the
108 * caller whether it must report this VF as malicious or not.
109 *
110 * 5. When a VF is identified to be malicious, the caller can send a message
111 * to the system administrator.
112 *
113 * 6. The PF is responsible for maintaining the struct ice_mbx_vf_info
114 * structure for each VF. The PF should clear the VF tracking structure if the
115 * VF is reset. When a VF is shut down and brought back up, we will then
116 * assume that the new VF is not malicious and may report it again if we
117 * detect it again.
118 *
119 * 7. The function ice_mbx_reset_snapshot() is called to reset the information
120 * in ice_mbx_snapshot for every new mailbox interrupt handled.
121 */
122 #define ICE_RQ_DATA_MASK(rq_data) ((rq_data) & PF_MBX_ARQH_ARQH_M)
123 /* Using the highest value for an unsigned 16-bit value 0xFFFF to indicate that
124 * the max messages check must be ignored in the algorithm
125 */
126 #define ICE_IGNORE_MAX_MSG_CNT 0xFFFF
127
128 /**
129 * ice_mbx_reset_snapshot - Reset mailbox snapshot structure
130 * @snap: pointer to the mailbox snapshot
131 */
ice_mbx_reset_snapshot(struct ice_mbx_snapshot * snap)132 static void ice_mbx_reset_snapshot(struct ice_mbx_snapshot *snap)
133 {
134 struct ice_mbx_vf_info *vf_info;
135
136 /* Clear mbx_buf in the mailbox snaphot structure and setting the
137 * mailbox snapshot state to a new capture.
138 */
139 memset(&snap->mbx_buf, 0, sizeof(snap->mbx_buf));
140 snap->mbx_buf.state = ICE_MAL_VF_DETECT_STATE_NEW_SNAPSHOT;
141
142 /* Reset message counts for all VFs to zero */
143 list_for_each_entry(vf_info, &snap->mbx_vf, list_entry)
144 vf_info->msg_count = 0;
145 }
146
147 /**
148 * ice_mbx_traverse - Pass through mailbox snapshot
149 * @hw: pointer to the HW struct
150 * @new_state: new algorithm state
151 *
152 * Traversing the mailbox static snapshot without checking
153 * for malicious VFs.
154 */
155 static void
ice_mbx_traverse(struct ice_hw * hw,enum ice_mbx_snapshot_state * new_state)156 ice_mbx_traverse(struct ice_hw *hw,
157 enum ice_mbx_snapshot_state *new_state)
158 {
159 struct ice_mbx_snap_buffer_data *snap_buf;
160 u32 num_iterations;
161
162 snap_buf = &hw->mbx_snapshot.mbx_buf;
163
164 /* As mailbox buffer is circular, applying a mask
165 * on the incremented iteration count.
166 */
167 num_iterations = ICE_RQ_DATA_MASK(++snap_buf->num_iterations);
168
169 /* Checking either of the below conditions to exit snapshot traversal:
170 * Condition-1: If the number of iterations in the mailbox is equal to
171 * the mailbox head which would indicate that we have reached the end
172 * of the static snapshot.
173 * Condition-2: If the maximum messages serviced in the mailbox for a
174 * given interrupt is the highest possible value then there is no need
175 * to check if the number of messages processed is equal to it. If not
176 * check if the number of messages processed is greater than or equal
177 * to the maximum number of mailbox entries serviced in current work item.
178 */
179 if (num_iterations == snap_buf->head ||
180 (snap_buf->max_num_msgs_mbx < ICE_IGNORE_MAX_MSG_CNT &&
181 ++snap_buf->num_msg_proc >= snap_buf->max_num_msgs_mbx))
182 *new_state = ICE_MAL_VF_DETECT_STATE_NEW_SNAPSHOT;
183 }
184
185 /**
186 * ice_mbx_detect_malvf - Detect malicious VF in snapshot
187 * @hw: pointer to the HW struct
188 * @vf_info: mailbox tracking structure for a VF
189 * @new_state: new algorithm state
190 * @is_malvf: boolean output to indicate if VF is malicious
191 *
192 * This function tracks the number of asynchronous messages
193 * sent per VF and marks the VF as malicious if it exceeds
194 * the permissible number of messages to send.
195 */
196 static int
ice_mbx_detect_malvf(struct ice_hw * hw,struct ice_mbx_vf_info * vf_info,enum ice_mbx_snapshot_state * new_state,bool * is_malvf)197 ice_mbx_detect_malvf(struct ice_hw *hw, struct ice_mbx_vf_info *vf_info,
198 enum ice_mbx_snapshot_state *new_state,
199 bool *is_malvf)
200 {
201 /* increment the message count for this VF */
202 vf_info->msg_count++;
203
204 if (vf_info->msg_count >= ICE_ASYNC_VF_MSG_THRESHOLD)
205 *is_malvf = true;
206
207 /* continue to iterate through the mailbox snapshot */
208 ice_mbx_traverse(hw, new_state);
209
210 return 0;
211 }
212
213 /**
214 * ice_mbx_vf_dec_trig_e830 - Decrements the VF mailbox queue counter
215 * @hw: pointer to the HW struct
216 * @event: pointer to the control queue receive event
217 *
218 * This function triggers to decrement the counter
219 * MBX_VF_IN_FLIGHT_MSGS_AT_PF_CNT when the driver replenishes
220 * the buffers at the PF mailbox queue.
221 */
ice_mbx_vf_dec_trig_e830(const struct ice_hw * hw,const struct ice_rq_event_info * event)222 void ice_mbx_vf_dec_trig_e830(const struct ice_hw *hw,
223 const struct ice_rq_event_info *event)
224 {
225 u16 vfid = le16_to_cpu(event->desc.retval);
226
227 wr32(hw, E830_MBX_VF_DEC_TRIG(vfid), 1);
228 }
229
230 /**
231 * ice_mbx_vf_clear_cnt_e830 - Clear the VF mailbox queue count
232 * @hw: pointer to the HW struct
233 * @vf_id: VF ID in the PF space
234 *
235 * This function clears the counter MBX_VF_IN_FLIGHT_MSGS_AT_PF_CNT, and should
236 * be called when a VF is created and on VF reset.
237 */
ice_mbx_vf_clear_cnt_e830(const struct ice_hw * hw,u16 vf_id)238 void ice_mbx_vf_clear_cnt_e830(const struct ice_hw *hw, u16 vf_id)
239 {
240 u32 reg = rd32(hw, E830_MBX_VF_IN_FLIGHT_MSGS_AT_PF_CNT(vf_id));
241
242 wr32(hw, E830_MBX_VF_DEC_TRIG(vf_id), reg);
243 }
244
245 /**
246 * ice_mbx_vf_state_handler - Handle states of the overflow algorithm
247 * @hw: pointer to the HW struct
248 * @mbx_data: pointer to structure containing mailbox data
249 * @vf_info: mailbox tracking structure for the VF in question
250 * @report_malvf: boolean output to indicate whether VF should be reported
251 *
252 * The function serves as an entry point for the malicious VF
253 * detection algorithm by handling the different states and state
254 * transitions of the algorithm:
255 * New snapshot: This state is entered when creating a new static
256 * snapshot. The data from any previous mailbox snapshot is
257 * cleared and a new capture of the mailbox head and tail is
258 * logged. This will be the new static snapshot to detect
259 * asynchronous messages sent by VFs. On capturing the snapshot
260 * and depending on whether the number of pending messages in that
261 * snapshot exceed the watermark value, the state machine enters
262 * traverse or detect states.
263 * Traverse: If pending message count is below watermark then iterate
264 * through the snapshot without any action on VF.
265 * Detect: If pending message count exceeds watermark traverse
266 * the static snapshot and look for a malicious VF.
267 */
268 int
ice_mbx_vf_state_handler(struct ice_hw * hw,struct ice_mbx_data * mbx_data,struct ice_mbx_vf_info * vf_info,bool * report_malvf)269 ice_mbx_vf_state_handler(struct ice_hw *hw, struct ice_mbx_data *mbx_data,
270 struct ice_mbx_vf_info *vf_info, bool *report_malvf)
271 {
272 struct ice_mbx_snapshot *snap = &hw->mbx_snapshot;
273 struct ice_mbx_snap_buffer_data *snap_buf;
274 struct ice_ctl_q_info *cq = &hw->mailboxq;
275 enum ice_mbx_snapshot_state new_state;
276 bool is_malvf = false;
277 int status = 0;
278
279 if (!report_malvf || !mbx_data || !vf_info)
280 return -EINVAL;
281
282 *report_malvf = false;
283
284 /* When entering the mailbox state machine assume that the VF
285 * is not malicious until detected.
286 */
287 /* Checking if max messages allowed to be processed while servicing current
288 * interrupt is not less than the defined AVF message threshold.
289 */
290 if (mbx_data->max_num_msgs_mbx <= ICE_ASYNC_VF_MSG_THRESHOLD)
291 return -EINVAL;
292
293 /* The watermark value should not be lesser than the threshold limit
294 * set for the number of asynchronous messages a VF can send to mailbox
295 * nor should it be greater than the maximum number of messages in the
296 * mailbox serviced in current interrupt.
297 */
298 if (mbx_data->async_watermark_val < ICE_ASYNC_VF_MSG_THRESHOLD ||
299 mbx_data->async_watermark_val > mbx_data->max_num_msgs_mbx)
300 return -EINVAL;
301
302 new_state = ICE_MAL_VF_DETECT_STATE_INVALID;
303 snap_buf = &snap->mbx_buf;
304
305 switch (snap_buf->state) {
306 case ICE_MAL_VF_DETECT_STATE_NEW_SNAPSHOT:
307 /* Clear any previously held data in mailbox snapshot structure. */
308 ice_mbx_reset_snapshot(snap);
309
310 /* Collect the pending ARQ count, number of messages processed and
311 * the maximum number of messages allowed to be processed from the
312 * Mailbox for current interrupt.
313 */
314 snap_buf->num_pending_arq = mbx_data->num_pending_arq;
315 snap_buf->num_msg_proc = mbx_data->num_msg_proc;
316 snap_buf->max_num_msgs_mbx = mbx_data->max_num_msgs_mbx;
317
318 /* Capture a new static snapshot of the mailbox by logging the
319 * head and tail of snapshot and set num_iterations to the tail
320 * value to mark the start of the iteration through the snapshot.
321 */
322 snap_buf->head = ICE_RQ_DATA_MASK(cq->rq.next_to_clean +
323 mbx_data->num_pending_arq);
324 snap_buf->tail = ICE_RQ_DATA_MASK(cq->rq.next_to_clean - 1);
325 snap_buf->num_iterations = snap_buf->tail;
326
327 /* Pending ARQ messages returned by ice_clean_rq_elem
328 * is the difference between the head and tail of the
329 * mailbox queue. Comparing this value against the watermark
330 * helps to check if we potentially have malicious VFs.
331 */
332 if (snap_buf->num_pending_arq >=
333 mbx_data->async_watermark_val) {
334 new_state = ICE_MAL_VF_DETECT_STATE_DETECT;
335 status = ice_mbx_detect_malvf(hw, vf_info, &new_state, &is_malvf);
336 } else {
337 new_state = ICE_MAL_VF_DETECT_STATE_TRAVERSE;
338 ice_mbx_traverse(hw, &new_state);
339 }
340 break;
341
342 case ICE_MAL_VF_DETECT_STATE_TRAVERSE:
343 new_state = ICE_MAL_VF_DETECT_STATE_TRAVERSE;
344 ice_mbx_traverse(hw, &new_state);
345 break;
346
347 case ICE_MAL_VF_DETECT_STATE_DETECT:
348 new_state = ICE_MAL_VF_DETECT_STATE_DETECT;
349 status = ice_mbx_detect_malvf(hw, vf_info, &new_state, &is_malvf);
350 break;
351
352 default:
353 new_state = ICE_MAL_VF_DETECT_STATE_INVALID;
354 status = -EIO;
355 }
356
357 snap_buf->state = new_state;
358
359 /* Only report VFs as malicious the first time we detect it */
360 if (is_malvf && !vf_info->malicious) {
361 vf_info->malicious = 1;
362 *report_malvf = true;
363 }
364
365 return status;
366 }
367
368 /**
369 * ice_mbx_clear_malvf - Clear VF mailbox info
370 * @vf_info: the mailbox tracking structure for a VF
371 *
372 * In case of a VF reset, this function shall be called to clear the VF's
373 * current mailbox tracking state.
374 */
ice_mbx_clear_malvf(struct ice_mbx_vf_info * vf_info)375 void ice_mbx_clear_malvf(struct ice_mbx_vf_info *vf_info)
376 {
377 vf_info->malicious = 0;
378 vf_info->msg_count = 0;
379 }
380
381 /**
382 * ice_mbx_init_vf_info - Initialize a new VF mailbox tracking info
383 * @hw: pointer to the hardware structure
384 * @vf_info: the mailbox tracking info structure for a VF
385 *
386 * Initialize a VF mailbox tracking info structure and insert it into the
387 * snapshot list.
388 *
389 * If you remove the VF, you must also delete the associated VF info structure
390 * from the linked list.
391 */
ice_mbx_init_vf_info(struct ice_hw * hw,struct ice_mbx_vf_info * vf_info)392 void ice_mbx_init_vf_info(struct ice_hw *hw, struct ice_mbx_vf_info *vf_info)
393 {
394 struct ice_mbx_snapshot *snap = &hw->mbx_snapshot;
395
396 ice_mbx_clear_malvf(vf_info);
397 list_add(&vf_info->list_entry, &snap->mbx_vf);
398 }
399
400 /**
401 * ice_mbx_init_snapshot - Initialize mailbox snapshot data
402 * @hw: pointer to the hardware structure
403 *
404 * Clear the mailbox snapshot structure and initialize the VF mailbox list.
405 */
ice_mbx_init_snapshot(struct ice_hw * hw)406 void ice_mbx_init_snapshot(struct ice_hw *hw)
407 {
408 struct ice_mbx_snapshot *snap = &hw->mbx_snapshot;
409
410 INIT_LIST_HEAD(&snap->mbx_vf);
411 ice_mbx_reset_snapshot(snap);
412 }
413