xref: /openbmc/linux/arch/powerpc/kvm/book3s_xics.c (revision 1fd02f66)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2012 Michael Ellerman, IBM Corporation.
4  * Copyright 2012 Benjamin Herrenschmidt, IBM Corporation.
5  */
6 
7 #include <linux/kernel.h>
8 #include <linux/kvm_host.h>
9 #include <linux/err.h>
10 #include <linux/gfp.h>
11 #include <linux/anon_inodes.h>
12 #include <linux/spinlock.h>
13 #include <linux/debugfs.h>
14 #include <linux/uaccess.h>
15 
16 #include <asm/kvm_book3s.h>
17 #include <asm/kvm_ppc.h>
18 #include <asm/hvcall.h>
19 #include <asm/xics.h>
20 #include <asm/time.h>
21 
22 #include <linux/seq_file.h>
23 
24 #include "book3s_xics.h"
25 
26 #if 1
27 #define XICS_DBG(fmt...) do { } while (0)
28 #else
29 #define XICS_DBG(fmt...) trace_printk(fmt)
30 #endif
31 
32 #define ENABLE_REALMODE	true
33 #define DEBUG_REALMODE	false
34 
35 /*
36  * LOCKING
37  * =======
38  *
39  * Each ICS has a spin lock protecting the information about the IRQ
40  * sources and avoiding simultaneous deliveries of the same interrupt.
41  *
42  * ICP operations are done via a single compare & swap transaction
43  * (most ICP state fits in the union kvmppc_icp_state)
44  */
45 
46 /*
47  * TODO
48  * ====
49  *
50  * - To speed up resends, keep a bitmap of "resend" set bits in the
51  *   ICS
52  *
53  * - Speed up server# -> ICP lookup (array ? hash table ?)
54  *
55  * - Make ICS lockless as well, or at least a per-interrupt lock or hashed
56  *   locks array to improve scalability
57  */
58 
59 /* -- ICS routines -- */
60 
61 static void icp_deliver_irq(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
62 			    u32 new_irq, bool check_resend);
63 
64 /*
65  * Return value ideally indicates how the interrupt was handled, but no
66  * callers look at it (given that we don't implement KVM_IRQ_LINE_STATUS),
67  * so just return 0.
68  */
ics_deliver_irq(struct kvmppc_xics * xics,u32 irq,u32 level)69 static int ics_deliver_irq(struct kvmppc_xics *xics, u32 irq, u32 level)
70 {
71 	struct ics_irq_state *state;
72 	struct kvmppc_ics *ics;
73 	u16 src;
74 	u32 pq_old, pq_new;
75 
76 	XICS_DBG("ics deliver %#x (level: %d)\n", irq, level);
77 
78 	ics = kvmppc_xics_find_ics(xics, irq, &src);
79 	if (!ics) {
80 		XICS_DBG("ics_deliver_irq: IRQ 0x%06x not found !\n", irq);
81 		return -EINVAL;
82 	}
83 	state = &ics->irq_state[src];
84 	if (!state->exists)
85 		return -EINVAL;
86 
87 	if (level == KVM_INTERRUPT_SET_LEVEL || level == KVM_INTERRUPT_SET)
88 		level = 1;
89 	else if (level == KVM_INTERRUPT_UNSET)
90 		level = 0;
91 	/*
92 	 * Take other values the same as 1, consistent with original code.
93 	 * maybe WARN here?
94 	 */
95 
96 	if (!state->lsi && level == 0) /* noop for MSI */
97 		return 0;
98 
99 	do {
100 		pq_old = state->pq_state;
101 		if (state->lsi) {
102 			if (level) {
103 				if (pq_old & PQ_PRESENTED)
104 					/* Setting already set LSI ... */
105 					return 0;
106 
107 				pq_new = PQ_PRESENTED;
108 			} else
109 				pq_new = 0;
110 		} else
111 			pq_new = ((pq_old << 1) & 3) | PQ_PRESENTED;
112 	} while (cmpxchg(&state->pq_state, pq_old, pq_new) != pq_old);
113 
114 	/* Test P=1, Q=0, this is the only case where we present */
115 	if (pq_new == PQ_PRESENTED)
116 		icp_deliver_irq(xics, NULL, irq, false);
117 
118 	/* Record which CPU this arrived on for passed-through interrupts */
119 	if (state->host_irq)
120 		state->intr_cpu = raw_smp_processor_id();
121 
122 	return 0;
123 }
124 
ics_check_resend(struct kvmppc_xics * xics,struct kvmppc_ics * ics,struct kvmppc_icp * icp)125 static void ics_check_resend(struct kvmppc_xics *xics, struct kvmppc_ics *ics,
126 			     struct kvmppc_icp *icp)
127 {
128 	int i;
129 
130 	for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
131 		struct ics_irq_state *state = &ics->irq_state[i];
132 		if (state->resend) {
133 			XICS_DBG("resend %#x prio %#x\n", state->number,
134 				      state->priority);
135 			icp_deliver_irq(xics, icp, state->number, true);
136 		}
137 	}
138 }
139 
write_xive(struct kvmppc_xics * xics,struct kvmppc_ics * ics,struct ics_irq_state * state,u32 server,u32 priority,u32 saved_priority)140 static bool write_xive(struct kvmppc_xics *xics, struct kvmppc_ics *ics,
141 		       struct ics_irq_state *state,
142 		       u32 server, u32 priority, u32 saved_priority)
143 {
144 	bool deliver;
145 	unsigned long flags;
146 
147 	local_irq_save(flags);
148 	arch_spin_lock(&ics->lock);
149 
150 	state->server = server;
151 	state->priority = priority;
152 	state->saved_priority = saved_priority;
153 	deliver = false;
154 	if ((state->masked_pending || state->resend) && priority != MASKED) {
155 		state->masked_pending = 0;
156 		state->resend = 0;
157 		deliver = true;
158 	}
159 
160 	arch_spin_unlock(&ics->lock);
161 	local_irq_restore(flags);
162 
163 	return deliver;
164 }
165 
kvmppc_xics_set_xive(struct kvm * kvm,u32 irq,u32 server,u32 priority)166 int kvmppc_xics_set_xive(struct kvm *kvm, u32 irq, u32 server, u32 priority)
167 {
168 	struct kvmppc_xics *xics = kvm->arch.xics;
169 	struct kvmppc_icp *icp;
170 	struct kvmppc_ics *ics;
171 	struct ics_irq_state *state;
172 	u16 src;
173 
174 	if (!xics)
175 		return -ENODEV;
176 
177 	ics = kvmppc_xics_find_ics(xics, irq, &src);
178 	if (!ics)
179 		return -EINVAL;
180 	state = &ics->irq_state[src];
181 
182 	icp = kvmppc_xics_find_server(kvm, server);
183 	if (!icp)
184 		return -EINVAL;
185 
186 	XICS_DBG("set_xive %#x server %#x prio %#x MP:%d RS:%d\n",
187 		 irq, server, priority,
188 		 state->masked_pending, state->resend);
189 
190 	if (write_xive(xics, ics, state, server, priority, priority))
191 		icp_deliver_irq(xics, icp, irq, false);
192 
193 	return 0;
194 }
195 
kvmppc_xics_get_xive(struct kvm * kvm,u32 irq,u32 * server,u32 * priority)196 int kvmppc_xics_get_xive(struct kvm *kvm, u32 irq, u32 *server, u32 *priority)
197 {
198 	struct kvmppc_xics *xics = kvm->arch.xics;
199 	struct kvmppc_ics *ics;
200 	struct ics_irq_state *state;
201 	u16 src;
202 	unsigned long flags;
203 
204 	if (!xics)
205 		return -ENODEV;
206 
207 	ics = kvmppc_xics_find_ics(xics, irq, &src);
208 	if (!ics)
209 		return -EINVAL;
210 	state = &ics->irq_state[src];
211 
212 	local_irq_save(flags);
213 	arch_spin_lock(&ics->lock);
214 	*server = state->server;
215 	*priority = state->priority;
216 	arch_spin_unlock(&ics->lock);
217 	local_irq_restore(flags);
218 
219 	return 0;
220 }
221 
kvmppc_xics_int_on(struct kvm * kvm,u32 irq)222 int kvmppc_xics_int_on(struct kvm *kvm, u32 irq)
223 {
224 	struct kvmppc_xics *xics = kvm->arch.xics;
225 	struct kvmppc_icp *icp;
226 	struct kvmppc_ics *ics;
227 	struct ics_irq_state *state;
228 	u16 src;
229 
230 	if (!xics)
231 		return -ENODEV;
232 
233 	ics = kvmppc_xics_find_ics(xics, irq, &src);
234 	if (!ics)
235 		return -EINVAL;
236 	state = &ics->irq_state[src];
237 
238 	icp = kvmppc_xics_find_server(kvm, state->server);
239 	if (!icp)
240 		return -EINVAL;
241 
242 	if (write_xive(xics, ics, state, state->server, state->saved_priority,
243 		       state->saved_priority))
244 		icp_deliver_irq(xics, icp, irq, false);
245 
246 	return 0;
247 }
248 
kvmppc_xics_int_off(struct kvm * kvm,u32 irq)249 int kvmppc_xics_int_off(struct kvm *kvm, u32 irq)
250 {
251 	struct kvmppc_xics *xics = kvm->arch.xics;
252 	struct kvmppc_ics *ics;
253 	struct ics_irq_state *state;
254 	u16 src;
255 
256 	if (!xics)
257 		return -ENODEV;
258 
259 	ics = kvmppc_xics_find_ics(xics, irq, &src);
260 	if (!ics)
261 		return -EINVAL;
262 	state = &ics->irq_state[src];
263 
264 	write_xive(xics, ics, state, state->server, MASKED, state->priority);
265 
266 	return 0;
267 }
268 
269 /* -- ICP routines, including hcalls -- */
270 
icp_try_update(struct kvmppc_icp * icp,union kvmppc_icp_state old,union kvmppc_icp_state new,bool change_self)271 static inline bool icp_try_update(struct kvmppc_icp *icp,
272 				  union kvmppc_icp_state old,
273 				  union kvmppc_icp_state new,
274 				  bool change_self)
275 {
276 	bool success;
277 
278 	/* Calculate new output value */
279 	new.out_ee = (new.xisr && (new.pending_pri < new.cppr));
280 
281 	/* Attempt atomic update */
282 	success = cmpxchg64(&icp->state.raw, old.raw, new.raw) == old.raw;
283 	if (!success)
284 		goto bail;
285 
286 	XICS_DBG("UPD [%04lx] - C:%02x M:%02x PP: %02x PI:%06x R:%d O:%d\n",
287 		 icp->server_num,
288 		 old.cppr, old.mfrr, old.pending_pri, old.xisr,
289 		 old.need_resend, old.out_ee);
290 	XICS_DBG("UPD        - C:%02x M:%02x PP: %02x PI:%06x R:%d O:%d\n",
291 		 new.cppr, new.mfrr, new.pending_pri, new.xisr,
292 		 new.need_resend, new.out_ee);
293 	/*
294 	 * Check for output state update
295 	 *
296 	 * Note that this is racy since another processor could be updating
297 	 * the state already. This is why we never clear the interrupt output
298 	 * here, we only ever set it. The clear only happens prior to doing
299 	 * an update and only by the processor itself. Currently we do it
300 	 * in Accept (H_XIRR) and Up_Cppr (H_XPPR).
301 	 *
302 	 * We also do not try to figure out whether the EE state has changed,
303 	 * we unconditionally set it if the new state calls for it. The reason
304 	 * for that is that we opportunistically remove the pending interrupt
305 	 * flag when raising CPPR, so we need to set it back here if an
306 	 * interrupt is still pending.
307 	 */
308 	if (new.out_ee) {
309 		kvmppc_book3s_queue_irqprio(icp->vcpu,
310 					    BOOK3S_INTERRUPT_EXTERNAL);
311 		if (!change_self)
312 			kvmppc_fast_vcpu_kick(icp->vcpu);
313 	}
314  bail:
315 	return success;
316 }
317 
icp_check_resend(struct kvmppc_xics * xics,struct kvmppc_icp * icp)318 static void icp_check_resend(struct kvmppc_xics *xics,
319 			     struct kvmppc_icp *icp)
320 {
321 	u32 icsid;
322 
323 	/* Order this load with the test for need_resend in the caller */
324 	smp_rmb();
325 	for_each_set_bit(icsid, icp->resend_map, xics->max_icsid + 1) {
326 		struct kvmppc_ics *ics = xics->ics[icsid];
327 
328 		if (!test_and_clear_bit(icsid, icp->resend_map))
329 			continue;
330 		if (!ics)
331 			continue;
332 		ics_check_resend(xics, ics, icp);
333 	}
334 }
335 
icp_try_to_deliver(struct kvmppc_icp * icp,u32 irq,u8 priority,u32 * reject)336 static bool icp_try_to_deliver(struct kvmppc_icp *icp, u32 irq, u8 priority,
337 			       u32 *reject)
338 {
339 	union kvmppc_icp_state old_state, new_state;
340 	bool success;
341 
342 	XICS_DBG("try deliver %#x(P:%#x) to server %#lx\n", irq, priority,
343 		 icp->server_num);
344 
345 	do {
346 		old_state = new_state = READ_ONCE(icp->state);
347 
348 		*reject = 0;
349 
350 		/* See if we can deliver */
351 		success = new_state.cppr > priority &&
352 			new_state.mfrr > priority &&
353 			new_state.pending_pri > priority;
354 
355 		/*
356 		 * If we can, check for a rejection and perform the
357 		 * delivery
358 		 */
359 		if (success) {
360 			*reject = new_state.xisr;
361 			new_state.xisr = irq;
362 			new_state.pending_pri = priority;
363 		} else {
364 			/*
365 			 * If we failed to deliver we set need_resend
366 			 * so a subsequent CPPR state change causes us
367 			 * to try a new delivery.
368 			 */
369 			new_state.need_resend = true;
370 		}
371 
372 	} while (!icp_try_update(icp, old_state, new_state, false));
373 
374 	return success;
375 }
376 
icp_deliver_irq(struct kvmppc_xics * xics,struct kvmppc_icp * icp,u32 new_irq,bool check_resend)377 static void icp_deliver_irq(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
378 			    u32 new_irq, bool check_resend)
379 {
380 	struct ics_irq_state *state;
381 	struct kvmppc_ics *ics;
382 	u32 reject;
383 	u16 src;
384 	unsigned long flags;
385 
386 	/*
387 	 * This is used both for initial delivery of an interrupt and
388 	 * for subsequent rejection.
389 	 *
390 	 * Rejection can be racy vs. resends. We have evaluated the
391 	 * rejection in an atomic ICP transaction which is now complete,
392 	 * so potentially the ICP can already accept the interrupt again.
393 	 *
394 	 * So we need to retry the delivery. Essentially the reject path
395 	 * boils down to a failed delivery. Always.
396 	 *
397 	 * Now the interrupt could also have moved to a different target,
398 	 * thus we may need to re-do the ICP lookup as well
399 	 */
400 
401  again:
402 	/* Get the ICS state and lock it */
403 	ics = kvmppc_xics_find_ics(xics, new_irq, &src);
404 	if (!ics) {
405 		XICS_DBG("icp_deliver_irq: IRQ 0x%06x not found !\n", new_irq);
406 		return;
407 	}
408 	state = &ics->irq_state[src];
409 
410 	/* Get a lock on the ICS */
411 	local_irq_save(flags);
412 	arch_spin_lock(&ics->lock);
413 
414 	/* Get our server */
415 	if (!icp || state->server != icp->server_num) {
416 		icp = kvmppc_xics_find_server(xics->kvm, state->server);
417 		if (!icp) {
418 			pr_warn("icp_deliver_irq: IRQ 0x%06x server 0x%x not found !\n",
419 				new_irq, state->server);
420 			goto out;
421 		}
422 	}
423 
424 	if (check_resend)
425 		if (!state->resend)
426 			goto out;
427 
428 	/* Clear the resend bit of that interrupt */
429 	state->resend = 0;
430 
431 	/*
432 	 * If masked, bail out
433 	 *
434 	 * Note: PAPR doesn't mention anything about masked pending
435 	 * when doing a resend, only when doing a delivery.
436 	 *
437 	 * However that would have the effect of losing a masked
438 	 * interrupt that was rejected and isn't consistent with
439 	 * the whole masked_pending business which is about not
440 	 * losing interrupts that occur while masked.
441 	 *
442 	 * I don't differentiate normal deliveries and resends, this
443 	 * implementation will differ from PAPR and not lose such
444 	 * interrupts.
445 	 */
446 	if (state->priority == MASKED) {
447 		XICS_DBG("irq %#x masked pending\n", new_irq);
448 		state->masked_pending = 1;
449 		goto out;
450 	}
451 
452 	/*
453 	 * Try the delivery, this will set the need_resend flag
454 	 * in the ICP as part of the atomic transaction if the
455 	 * delivery is not possible.
456 	 *
457 	 * Note that if successful, the new delivery might have itself
458 	 * rejected an interrupt that was "delivered" before we took the
459 	 * ics spin lock.
460 	 *
461 	 * In this case we do the whole sequence all over again for the
462 	 * new guy. We cannot assume that the rejected interrupt is less
463 	 * favored than the new one, and thus doesn't need to be delivered,
464 	 * because by the time we exit icp_try_to_deliver() the target
465 	 * processor may well have already consumed & completed it, and thus
466 	 * the rejected interrupt might actually be already acceptable.
467 	 */
468 	if (icp_try_to_deliver(icp, new_irq, state->priority, &reject)) {
469 		/*
470 		 * Delivery was successful, did we reject somebody else ?
471 		 */
472 		if (reject && reject != XICS_IPI) {
473 			arch_spin_unlock(&ics->lock);
474 			local_irq_restore(flags);
475 			new_irq = reject;
476 			check_resend = false;
477 			goto again;
478 		}
479 	} else {
480 		/*
481 		 * We failed to deliver the interrupt we need to set the
482 		 * resend map bit and mark the ICS state as needing a resend
483 		 */
484 		state->resend = 1;
485 
486 		/*
487 		 * Make sure when checking resend, we don't miss the resend
488 		 * if resend_map bit is seen and cleared.
489 		 */
490 		smp_wmb();
491 		set_bit(ics->icsid, icp->resend_map);
492 
493 		/*
494 		 * If the need_resend flag got cleared in the ICP some time
495 		 * between icp_try_to_deliver() atomic update and now, then
496 		 * we know it might have missed the resend_map bit. So we
497 		 * retry
498 		 */
499 		smp_mb();
500 		if (!icp->state.need_resend) {
501 			state->resend = 0;
502 			arch_spin_unlock(&ics->lock);
503 			local_irq_restore(flags);
504 			check_resend = false;
505 			goto again;
506 		}
507 	}
508  out:
509 	arch_spin_unlock(&ics->lock);
510 	local_irq_restore(flags);
511 }
512 
icp_down_cppr(struct kvmppc_xics * xics,struct kvmppc_icp * icp,u8 new_cppr)513 static void icp_down_cppr(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
514 			  u8 new_cppr)
515 {
516 	union kvmppc_icp_state old_state, new_state;
517 	bool resend;
518 
519 	/*
520 	 * This handles several related states in one operation:
521 	 *
522 	 * ICP State: Down_CPPR
523 	 *
524 	 * Load CPPR with new value and if the XISR is 0
525 	 * then check for resends:
526 	 *
527 	 * ICP State: Resend
528 	 *
529 	 * If MFRR is more favored than CPPR, check for IPIs
530 	 * and notify ICS of a potential resend. This is done
531 	 * asynchronously (when used in real mode, we will have
532 	 * to exit here).
533 	 *
534 	 * We do not handle the complete Check_IPI as documented
535 	 * here. In the PAPR, this state will be used for both
536 	 * Set_MFRR and Down_CPPR. However, we know that we aren't
537 	 * changing the MFRR state here so we don't need to handle
538 	 * the case of an MFRR causing a reject of a pending irq,
539 	 * this will have been handled when the MFRR was set in the
540 	 * first place.
541 	 *
542 	 * Thus we don't have to handle rejects, only resends.
543 	 *
544 	 * When implementing real mode for HV KVM, resend will lead to
545 	 * a H_TOO_HARD return and the whole transaction will be handled
546 	 * in virtual mode.
547 	 */
548 	do {
549 		old_state = new_state = READ_ONCE(icp->state);
550 
551 		/* Down_CPPR */
552 		new_state.cppr = new_cppr;
553 
554 		/*
555 		 * Cut down Resend / Check_IPI / IPI
556 		 *
557 		 * The logic is that we cannot have a pending interrupt
558 		 * trumped by an IPI at this point (see above), so we
559 		 * know that either the pending interrupt is already an
560 		 * IPI (in which case we don't care to override it) or
561 		 * it's either more favored than us or non existent
562 		 */
563 		if (new_state.mfrr < new_cppr &&
564 		    new_state.mfrr <= new_state.pending_pri) {
565 			WARN_ON(new_state.xisr != XICS_IPI &&
566 				new_state.xisr != 0);
567 			new_state.pending_pri = new_state.mfrr;
568 			new_state.xisr = XICS_IPI;
569 		}
570 
571 		/* Latch/clear resend bit */
572 		resend = new_state.need_resend;
573 		new_state.need_resend = 0;
574 
575 	} while (!icp_try_update(icp, old_state, new_state, true));
576 
577 	/*
578 	 * Now handle resend checks. Those are asynchronous to the ICP
579 	 * state update in HW (ie bus transactions) so we can handle them
580 	 * separately here too
581 	 */
582 	if (resend)
583 		icp_check_resend(xics, icp);
584 }
585 
kvmppc_h_xirr(struct kvm_vcpu * vcpu)586 static noinline unsigned long kvmppc_h_xirr(struct kvm_vcpu *vcpu)
587 {
588 	union kvmppc_icp_state old_state, new_state;
589 	struct kvmppc_icp *icp = vcpu->arch.icp;
590 	u32 xirr;
591 
592 	/* First, remove EE from the processor */
593 	kvmppc_book3s_dequeue_irqprio(icp->vcpu, BOOK3S_INTERRUPT_EXTERNAL);
594 
595 	/*
596 	 * ICP State: Accept_Interrupt
597 	 *
598 	 * Return the pending interrupt (if any) along with the
599 	 * current CPPR, then clear the XISR & set CPPR to the
600 	 * pending priority
601 	 */
602 	do {
603 		old_state = new_state = READ_ONCE(icp->state);
604 
605 		xirr = old_state.xisr | (((u32)old_state.cppr) << 24);
606 		if (!old_state.xisr)
607 			break;
608 		new_state.cppr = new_state.pending_pri;
609 		new_state.pending_pri = 0xff;
610 		new_state.xisr = 0;
611 
612 	} while (!icp_try_update(icp, old_state, new_state, true));
613 
614 	XICS_DBG("h_xirr vcpu %d xirr %#x\n", vcpu->vcpu_id, xirr);
615 
616 	return xirr;
617 }
618 
kvmppc_h_ipi(struct kvm_vcpu * vcpu,unsigned long server,unsigned long mfrr)619 static noinline int kvmppc_h_ipi(struct kvm_vcpu *vcpu, unsigned long server,
620 				 unsigned long mfrr)
621 {
622 	union kvmppc_icp_state old_state, new_state;
623 	struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
624 	struct kvmppc_icp *icp;
625 	u32 reject;
626 	bool resend;
627 	bool local;
628 
629 	XICS_DBG("h_ipi vcpu %d to server %lu mfrr %#lx\n",
630 		 vcpu->vcpu_id, server, mfrr);
631 
632 	icp = vcpu->arch.icp;
633 	local = icp->server_num == server;
634 	if (!local) {
635 		icp = kvmppc_xics_find_server(vcpu->kvm, server);
636 		if (!icp)
637 			return H_PARAMETER;
638 	}
639 
640 	/*
641 	 * ICP state: Set_MFRR
642 	 *
643 	 * If the CPPR is more favored than the new MFRR, then
644 	 * nothing needs to be rejected as there can be no XISR to
645 	 * reject.  If the MFRR is being made less favored then
646 	 * there might be a previously-rejected interrupt needing
647 	 * to be resent.
648 	 *
649 	 * ICP state: Check_IPI
650 	 *
651 	 * If the CPPR is less favored, then we might be replacing
652 	 * an interrupt, and thus need to possibly reject it.
653 	 *
654 	 * ICP State: IPI
655 	 *
656 	 * Besides rejecting any pending interrupts, we also
657 	 * update XISR and pending_pri to mark IPI as pending.
658 	 *
659 	 * PAPR does not describe this state, but if the MFRR is being
660 	 * made less favored than its earlier value, there might be
661 	 * a previously-rejected interrupt needing to be resent.
662 	 * Ideally, we would want to resend only if
663 	 *	prio(pending_interrupt) < mfrr &&
664 	 *	prio(pending_interrupt) < cppr
665 	 * where pending interrupt is the one that was rejected. But
666 	 * we don't have that state, so we simply trigger a resend
667 	 * whenever the MFRR is made less favored.
668 	 */
669 	do {
670 		old_state = new_state = READ_ONCE(icp->state);
671 
672 		/* Set_MFRR */
673 		new_state.mfrr = mfrr;
674 
675 		/* Check_IPI */
676 		reject = 0;
677 		resend = false;
678 		if (mfrr < new_state.cppr) {
679 			/* Reject a pending interrupt if not an IPI */
680 			if (mfrr <= new_state.pending_pri) {
681 				reject = new_state.xisr;
682 				new_state.pending_pri = mfrr;
683 				new_state.xisr = XICS_IPI;
684 			}
685 		}
686 
687 		if (mfrr > old_state.mfrr) {
688 			resend = new_state.need_resend;
689 			new_state.need_resend = 0;
690 		}
691 	} while (!icp_try_update(icp, old_state, new_state, local));
692 
693 	/* Handle reject */
694 	if (reject && reject != XICS_IPI)
695 		icp_deliver_irq(xics, icp, reject, false);
696 
697 	/* Handle resend */
698 	if (resend)
699 		icp_check_resend(xics, icp);
700 
701 	return H_SUCCESS;
702 }
703 
kvmppc_h_ipoll(struct kvm_vcpu * vcpu,unsigned long server)704 static int kvmppc_h_ipoll(struct kvm_vcpu *vcpu, unsigned long server)
705 {
706 	union kvmppc_icp_state state;
707 	struct kvmppc_icp *icp;
708 
709 	icp = vcpu->arch.icp;
710 	if (icp->server_num != server) {
711 		icp = kvmppc_xics_find_server(vcpu->kvm, server);
712 		if (!icp)
713 			return H_PARAMETER;
714 	}
715 	state = READ_ONCE(icp->state);
716 	kvmppc_set_gpr(vcpu, 4, ((u32)state.cppr << 24) | state.xisr);
717 	kvmppc_set_gpr(vcpu, 5, state.mfrr);
718 	return H_SUCCESS;
719 }
720 
kvmppc_h_cppr(struct kvm_vcpu * vcpu,unsigned long cppr)721 static noinline void kvmppc_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr)
722 {
723 	union kvmppc_icp_state old_state, new_state;
724 	struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
725 	struct kvmppc_icp *icp = vcpu->arch.icp;
726 	u32 reject;
727 
728 	XICS_DBG("h_cppr vcpu %d cppr %#lx\n", vcpu->vcpu_id, cppr);
729 
730 	/*
731 	 * ICP State: Set_CPPR
732 	 *
733 	 * We can safely compare the new value with the current
734 	 * value outside of the transaction as the CPPR is only
735 	 * ever changed by the processor on itself
736 	 */
737 	if (cppr > icp->state.cppr)
738 		icp_down_cppr(xics, icp, cppr);
739 	else if (cppr == icp->state.cppr)
740 		return;
741 
742 	/*
743 	 * ICP State: Up_CPPR
744 	 *
745 	 * The processor is raising its priority, this can result
746 	 * in a rejection of a pending interrupt:
747 	 *
748 	 * ICP State: Reject_Current
749 	 *
750 	 * We can remove EE from the current processor, the update
751 	 * transaction will set it again if needed
752 	 */
753 	kvmppc_book3s_dequeue_irqprio(icp->vcpu, BOOK3S_INTERRUPT_EXTERNAL);
754 
755 	do {
756 		old_state = new_state = READ_ONCE(icp->state);
757 
758 		reject = 0;
759 		new_state.cppr = cppr;
760 
761 		if (cppr <= new_state.pending_pri) {
762 			reject = new_state.xisr;
763 			new_state.xisr = 0;
764 			new_state.pending_pri = 0xff;
765 		}
766 
767 	} while (!icp_try_update(icp, old_state, new_state, true));
768 
769 	/*
770 	 * Check for rejects. They are handled by doing a new delivery
771 	 * attempt (see comments in icp_deliver_irq).
772 	 */
773 	if (reject && reject != XICS_IPI)
774 		icp_deliver_irq(xics, icp, reject, false);
775 }
776 
ics_eoi(struct kvm_vcpu * vcpu,u32 irq)777 static int ics_eoi(struct kvm_vcpu *vcpu, u32 irq)
778 {
779 	struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
780 	struct kvmppc_icp *icp = vcpu->arch.icp;
781 	struct kvmppc_ics *ics;
782 	struct ics_irq_state *state;
783 	u16 src;
784 	u32 pq_old, pq_new;
785 
786 	/*
787 	 * ICS EOI handling: For LSI, if P bit is still set, we need to
788 	 * resend it.
789 	 *
790 	 * For MSI, we move Q bit into P (and clear Q). If it is set,
791 	 * resend it.
792 	 */
793 
794 	ics = kvmppc_xics_find_ics(xics, irq, &src);
795 	if (!ics) {
796 		XICS_DBG("ios_eoi: IRQ 0x%06x not found !\n", irq);
797 		return H_PARAMETER;
798 	}
799 	state = &ics->irq_state[src];
800 
801 	if (state->lsi)
802 		pq_new = state->pq_state;
803 	else
804 		do {
805 			pq_old = state->pq_state;
806 			pq_new = pq_old >> 1;
807 		} while (cmpxchg(&state->pq_state, pq_old, pq_new) != pq_old);
808 
809 	if (pq_new & PQ_PRESENTED)
810 		icp_deliver_irq(xics, icp, irq, false);
811 
812 	kvm_notify_acked_irq(vcpu->kvm, 0, irq);
813 
814 	return H_SUCCESS;
815 }
816 
kvmppc_h_eoi(struct kvm_vcpu * vcpu,unsigned long xirr)817 static noinline int kvmppc_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr)
818 {
819 	struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
820 	struct kvmppc_icp *icp = vcpu->arch.icp;
821 	u32 irq = xirr & 0x00ffffff;
822 
823 	XICS_DBG("h_eoi vcpu %d eoi %#lx\n", vcpu->vcpu_id, xirr);
824 
825 	/*
826 	 * ICP State: EOI
827 	 *
828 	 * Note: If EOI is incorrectly used by SW to lower the CPPR
829 	 * value (ie more favored), we do not check for rejection of
830 	 * a pending interrupt, this is a SW error and PAPR specifies
831 	 * that we don't have to deal with it.
832 	 *
833 	 * The sending of an EOI to the ICS is handled after the
834 	 * CPPR update
835 	 *
836 	 * ICP State: Down_CPPR which we handle
837 	 * in a separate function as it's shared with H_CPPR.
838 	 */
839 	icp_down_cppr(xics, icp, xirr >> 24);
840 
841 	/* IPIs have no EOI */
842 	if (irq == XICS_IPI)
843 		return H_SUCCESS;
844 
845 	return ics_eoi(vcpu, irq);
846 }
847 
kvmppc_xics_rm_complete(struct kvm_vcpu * vcpu,u32 hcall)848 int kvmppc_xics_rm_complete(struct kvm_vcpu *vcpu, u32 hcall)
849 {
850 	struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
851 	struct kvmppc_icp *icp = vcpu->arch.icp;
852 
853 	XICS_DBG("XICS_RM: H_%x completing, act: %x state: %lx tgt: %p\n",
854 		 hcall, icp->rm_action, icp->rm_dbgstate.raw, icp->rm_dbgtgt);
855 
856 	if (icp->rm_action & XICS_RM_KICK_VCPU) {
857 		icp->n_rm_kick_vcpu++;
858 		kvmppc_fast_vcpu_kick(icp->rm_kick_target);
859 	}
860 	if (icp->rm_action & XICS_RM_CHECK_RESEND) {
861 		icp->n_rm_check_resend++;
862 		icp_check_resend(xics, icp->rm_resend_icp);
863 	}
864 	if (icp->rm_action & XICS_RM_NOTIFY_EOI) {
865 		icp->n_rm_notify_eoi++;
866 		kvm_notify_acked_irq(vcpu->kvm, 0, icp->rm_eoied_irq);
867 	}
868 
869 	icp->rm_action = 0;
870 
871 	return H_SUCCESS;
872 }
873 EXPORT_SYMBOL_GPL(kvmppc_xics_rm_complete);
874 
kvmppc_xics_hcall(struct kvm_vcpu * vcpu,u32 req)875 int kvmppc_xics_hcall(struct kvm_vcpu *vcpu, u32 req)
876 {
877 	struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
878 	unsigned long res;
879 	int rc = H_SUCCESS;
880 
881 	/* Check if we have an ICP */
882 	if (!xics || !vcpu->arch.icp)
883 		return H_HARDWARE;
884 
885 	/* These requests don't have real-mode implementations at present */
886 	switch (req) {
887 	case H_XIRR_X:
888 		res = kvmppc_h_xirr(vcpu);
889 		kvmppc_set_gpr(vcpu, 4, res);
890 		kvmppc_set_gpr(vcpu, 5, get_tb());
891 		return rc;
892 	case H_IPOLL:
893 		rc = kvmppc_h_ipoll(vcpu, kvmppc_get_gpr(vcpu, 4));
894 		return rc;
895 	}
896 
897 	/* Check for real mode returning too hard */
898 	if (xics->real_mode && is_kvmppc_hv_enabled(vcpu->kvm))
899 		return kvmppc_xics_rm_complete(vcpu, req);
900 
901 	switch (req) {
902 	case H_XIRR:
903 		res = kvmppc_h_xirr(vcpu);
904 		kvmppc_set_gpr(vcpu, 4, res);
905 		break;
906 	case H_CPPR:
907 		kvmppc_h_cppr(vcpu, kvmppc_get_gpr(vcpu, 4));
908 		break;
909 	case H_EOI:
910 		rc = kvmppc_h_eoi(vcpu, kvmppc_get_gpr(vcpu, 4));
911 		break;
912 	case H_IPI:
913 		rc = kvmppc_h_ipi(vcpu, kvmppc_get_gpr(vcpu, 4),
914 				  kvmppc_get_gpr(vcpu, 5));
915 		break;
916 	}
917 
918 	return rc;
919 }
920 EXPORT_SYMBOL_GPL(kvmppc_xics_hcall);
921 
922 
923 /* -- Initialisation code etc. -- */
924 
xics_debugfs_irqmap(struct seq_file * m,struct kvmppc_passthru_irqmap * pimap)925 static void xics_debugfs_irqmap(struct seq_file *m,
926 				struct kvmppc_passthru_irqmap *pimap)
927 {
928 	int i;
929 
930 	if (!pimap)
931 		return;
932 	seq_printf(m, "========\nPIRQ mappings: %d maps\n===========\n",
933 				pimap->n_mapped);
934 	for (i = 0; i < pimap->n_mapped; i++)  {
935 		seq_printf(m, "r_hwirq=%x, v_hwirq=%x\n",
936 			pimap->mapped[i].r_hwirq, pimap->mapped[i].v_hwirq);
937 	}
938 }
939 
xics_debug_show(struct seq_file * m,void * private)940 static int xics_debug_show(struct seq_file *m, void *private)
941 {
942 	struct kvmppc_xics *xics = m->private;
943 	struct kvm *kvm = xics->kvm;
944 	struct kvm_vcpu *vcpu;
945 	int icsid;
946 	unsigned long flags, i;
947 	unsigned long t_rm_kick_vcpu, t_rm_check_resend;
948 	unsigned long t_rm_notify_eoi;
949 	unsigned long t_reject, t_check_resend;
950 
951 	if (!kvm)
952 		return 0;
953 
954 	t_rm_kick_vcpu = 0;
955 	t_rm_notify_eoi = 0;
956 	t_rm_check_resend = 0;
957 	t_check_resend = 0;
958 	t_reject = 0;
959 
960 	xics_debugfs_irqmap(m, kvm->arch.pimap);
961 
962 	seq_printf(m, "=========\nICP state\n=========\n");
963 
964 	kvm_for_each_vcpu(i, vcpu, kvm) {
965 		struct kvmppc_icp *icp = vcpu->arch.icp;
966 		union kvmppc_icp_state state;
967 
968 		if (!icp)
969 			continue;
970 
971 		state.raw = READ_ONCE(icp->state.raw);
972 		seq_printf(m, "cpu server %#lx XIRR:%#x PPRI:%#x CPPR:%#x MFRR:%#x OUT:%d NR:%d\n",
973 			   icp->server_num, state.xisr,
974 			   state.pending_pri, state.cppr, state.mfrr,
975 			   state.out_ee, state.need_resend);
976 		t_rm_kick_vcpu += icp->n_rm_kick_vcpu;
977 		t_rm_notify_eoi += icp->n_rm_notify_eoi;
978 		t_rm_check_resend += icp->n_rm_check_resend;
979 		t_check_resend += icp->n_check_resend;
980 		t_reject += icp->n_reject;
981 	}
982 
983 	seq_printf(m, "ICP Guest->Host totals: kick_vcpu=%lu check_resend=%lu notify_eoi=%lu\n",
984 			t_rm_kick_vcpu, t_rm_check_resend,
985 			t_rm_notify_eoi);
986 	seq_printf(m, "ICP Real Mode totals: check_resend=%lu resend=%lu\n",
987 			t_check_resend, t_reject);
988 	for (icsid = 0; icsid <= KVMPPC_XICS_MAX_ICS_ID; icsid++) {
989 		struct kvmppc_ics *ics = xics->ics[icsid];
990 
991 		if (!ics)
992 			continue;
993 
994 		seq_printf(m, "=========\nICS state for ICS 0x%x\n=========\n",
995 			   icsid);
996 
997 		local_irq_save(flags);
998 		arch_spin_lock(&ics->lock);
999 
1000 		for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
1001 			struct ics_irq_state *irq = &ics->irq_state[i];
1002 
1003 			seq_printf(m, "irq 0x%06x: server %#x prio %#x save prio %#x pq_state %d resend %d masked pending %d\n",
1004 				   irq->number, irq->server, irq->priority,
1005 				   irq->saved_priority, irq->pq_state,
1006 				   irq->resend, irq->masked_pending);
1007 
1008 		}
1009 		arch_spin_unlock(&ics->lock);
1010 		local_irq_restore(flags);
1011 	}
1012 	return 0;
1013 }
1014 
1015 DEFINE_SHOW_ATTRIBUTE(xics_debug);
1016 
xics_debugfs_init(struct kvmppc_xics * xics)1017 static void xics_debugfs_init(struct kvmppc_xics *xics)
1018 {
1019 	xics->dentry = debugfs_create_file("xics", 0444, xics->kvm->debugfs_dentry,
1020 					   xics, &xics_debug_fops);
1021 
1022 	pr_debug("%s: created\n", __func__);
1023 }
1024 
kvmppc_xics_create_ics(struct kvm * kvm,struct kvmppc_xics * xics,int irq)1025 static struct kvmppc_ics *kvmppc_xics_create_ics(struct kvm *kvm,
1026 					struct kvmppc_xics *xics, int irq)
1027 {
1028 	struct kvmppc_ics *ics;
1029 	int i, icsid;
1030 
1031 	icsid = irq >> KVMPPC_XICS_ICS_SHIFT;
1032 
1033 	mutex_lock(&kvm->lock);
1034 
1035 	/* ICS already exists - somebody else got here first */
1036 	if (xics->ics[icsid])
1037 		goto out;
1038 
1039 	/* Create the ICS */
1040 	ics = kzalloc(sizeof(struct kvmppc_ics), GFP_KERNEL);
1041 	if (!ics)
1042 		goto out;
1043 
1044 	ics->icsid = icsid;
1045 
1046 	for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
1047 		ics->irq_state[i].number = (icsid << KVMPPC_XICS_ICS_SHIFT) | i;
1048 		ics->irq_state[i].priority = MASKED;
1049 		ics->irq_state[i].saved_priority = MASKED;
1050 	}
1051 	smp_wmb();
1052 	xics->ics[icsid] = ics;
1053 
1054 	if (icsid > xics->max_icsid)
1055 		xics->max_icsid = icsid;
1056 
1057  out:
1058 	mutex_unlock(&kvm->lock);
1059 	return xics->ics[icsid];
1060 }
1061 
kvmppc_xics_create_icp(struct kvm_vcpu * vcpu,unsigned long server_num)1062 static int kvmppc_xics_create_icp(struct kvm_vcpu *vcpu, unsigned long server_num)
1063 {
1064 	struct kvmppc_icp *icp;
1065 
1066 	if (!vcpu->kvm->arch.xics)
1067 		return -ENODEV;
1068 
1069 	if (kvmppc_xics_find_server(vcpu->kvm, server_num))
1070 		return -EEXIST;
1071 
1072 	icp = kzalloc(sizeof(struct kvmppc_icp), GFP_KERNEL);
1073 	if (!icp)
1074 		return -ENOMEM;
1075 
1076 	icp->vcpu = vcpu;
1077 	icp->server_num = server_num;
1078 	icp->state.mfrr = MASKED;
1079 	icp->state.pending_pri = MASKED;
1080 	vcpu->arch.icp = icp;
1081 
1082 	XICS_DBG("created server for vcpu %d\n", vcpu->vcpu_id);
1083 
1084 	return 0;
1085 }
1086 
kvmppc_xics_get_icp(struct kvm_vcpu * vcpu)1087 u64 kvmppc_xics_get_icp(struct kvm_vcpu *vcpu)
1088 {
1089 	struct kvmppc_icp *icp = vcpu->arch.icp;
1090 	union kvmppc_icp_state state;
1091 
1092 	if (!icp)
1093 		return 0;
1094 	state = icp->state;
1095 	return ((u64)state.cppr << KVM_REG_PPC_ICP_CPPR_SHIFT) |
1096 		((u64)state.xisr << KVM_REG_PPC_ICP_XISR_SHIFT) |
1097 		((u64)state.mfrr << KVM_REG_PPC_ICP_MFRR_SHIFT) |
1098 		((u64)state.pending_pri << KVM_REG_PPC_ICP_PPRI_SHIFT);
1099 }
1100 
kvmppc_xics_set_icp(struct kvm_vcpu * vcpu,u64 icpval)1101 int kvmppc_xics_set_icp(struct kvm_vcpu *vcpu, u64 icpval)
1102 {
1103 	struct kvmppc_icp *icp = vcpu->arch.icp;
1104 	struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
1105 	union kvmppc_icp_state old_state, new_state;
1106 	struct kvmppc_ics *ics;
1107 	u8 cppr, mfrr, pending_pri;
1108 	u32 xisr;
1109 	u16 src;
1110 	bool resend;
1111 
1112 	if (!icp || !xics)
1113 		return -ENOENT;
1114 
1115 	cppr = icpval >> KVM_REG_PPC_ICP_CPPR_SHIFT;
1116 	xisr = (icpval >> KVM_REG_PPC_ICP_XISR_SHIFT) &
1117 		KVM_REG_PPC_ICP_XISR_MASK;
1118 	mfrr = icpval >> KVM_REG_PPC_ICP_MFRR_SHIFT;
1119 	pending_pri = icpval >> KVM_REG_PPC_ICP_PPRI_SHIFT;
1120 
1121 	/* Require the new state to be internally consistent */
1122 	if (xisr == 0) {
1123 		if (pending_pri != 0xff)
1124 			return -EINVAL;
1125 	} else if (xisr == XICS_IPI) {
1126 		if (pending_pri != mfrr || pending_pri >= cppr)
1127 			return -EINVAL;
1128 	} else {
1129 		if (pending_pri >= mfrr || pending_pri >= cppr)
1130 			return -EINVAL;
1131 		ics = kvmppc_xics_find_ics(xics, xisr, &src);
1132 		if (!ics)
1133 			return -EINVAL;
1134 	}
1135 
1136 	new_state.raw = 0;
1137 	new_state.cppr = cppr;
1138 	new_state.xisr = xisr;
1139 	new_state.mfrr = mfrr;
1140 	new_state.pending_pri = pending_pri;
1141 
1142 	/*
1143 	 * Deassert the CPU interrupt request.
1144 	 * icp_try_update will reassert it if necessary.
1145 	 */
1146 	kvmppc_book3s_dequeue_irqprio(icp->vcpu, BOOK3S_INTERRUPT_EXTERNAL);
1147 
1148 	/*
1149 	 * Note that if we displace an interrupt from old_state.xisr,
1150 	 * we don't mark it as rejected.  We expect userspace to set
1151 	 * the state of the interrupt sources to be consistent with
1152 	 * the ICP states (either before or afterwards, which doesn't
1153 	 * matter).  We do handle resends due to CPPR becoming less
1154 	 * favoured because that is necessary to end up with a
1155 	 * consistent state in the situation where userspace restores
1156 	 * the ICS states before the ICP states.
1157 	 */
1158 	do {
1159 		old_state = READ_ONCE(icp->state);
1160 
1161 		if (new_state.mfrr <= old_state.mfrr) {
1162 			resend = false;
1163 			new_state.need_resend = old_state.need_resend;
1164 		} else {
1165 			resend = old_state.need_resend;
1166 			new_state.need_resend = 0;
1167 		}
1168 	} while (!icp_try_update(icp, old_state, new_state, false));
1169 
1170 	if (resend)
1171 		icp_check_resend(xics, icp);
1172 
1173 	return 0;
1174 }
1175 
xics_get_source(struct kvmppc_xics * xics,long irq,u64 addr)1176 static int xics_get_source(struct kvmppc_xics *xics, long irq, u64 addr)
1177 {
1178 	int ret;
1179 	struct kvmppc_ics *ics;
1180 	struct ics_irq_state *irqp;
1181 	u64 __user *ubufp = (u64 __user *) addr;
1182 	u16 idx;
1183 	u64 val, prio;
1184 	unsigned long flags;
1185 
1186 	ics = kvmppc_xics_find_ics(xics, irq, &idx);
1187 	if (!ics)
1188 		return -ENOENT;
1189 
1190 	irqp = &ics->irq_state[idx];
1191 	local_irq_save(flags);
1192 	arch_spin_lock(&ics->lock);
1193 	ret = -ENOENT;
1194 	if (irqp->exists) {
1195 		val = irqp->server;
1196 		prio = irqp->priority;
1197 		if (prio == MASKED) {
1198 			val |= KVM_XICS_MASKED;
1199 			prio = irqp->saved_priority;
1200 		}
1201 		val |= prio << KVM_XICS_PRIORITY_SHIFT;
1202 		if (irqp->lsi) {
1203 			val |= KVM_XICS_LEVEL_SENSITIVE;
1204 			if (irqp->pq_state & PQ_PRESENTED)
1205 				val |= KVM_XICS_PENDING;
1206 		} else if (irqp->masked_pending || irqp->resend)
1207 			val |= KVM_XICS_PENDING;
1208 
1209 		if (irqp->pq_state & PQ_PRESENTED)
1210 			val |= KVM_XICS_PRESENTED;
1211 
1212 		if (irqp->pq_state & PQ_QUEUED)
1213 			val |= KVM_XICS_QUEUED;
1214 
1215 		ret = 0;
1216 	}
1217 	arch_spin_unlock(&ics->lock);
1218 	local_irq_restore(flags);
1219 
1220 	if (!ret && put_user(val, ubufp))
1221 		ret = -EFAULT;
1222 
1223 	return ret;
1224 }
1225 
xics_set_source(struct kvmppc_xics * xics,long irq,u64 addr)1226 static int xics_set_source(struct kvmppc_xics *xics, long irq, u64 addr)
1227 {
1228 	struct kvmppc_ics *ics;
1229 	struct ics_irq_state *irqp;
1230 	u64 __user *ubufp = (u64 __user *) addr;
1231 	u16 idx;
1232 	u64 val;
1233 	u8 prio;
1234 	u32 server;
1235 	unsigned long flags;
1236 
1237 	if (irq < KVMPPC_XICS_FIRST_IRQ || irq >= KVMPPC_XICS_NR_IRQS)
1238 		return -ENOENT;
1239 
1240 	ics = kvmppc_xics_find_ics(xics, irq, &idx);
1241 	if (!ics) {
1242 		ics = kvmppc_xics_create_ics(xics->kvm, xics, irq);
1243 		if (!ics)
1244 			return -ENOMEM;
1245 	}
1246 	irqp = &ics->irq_state[idx];
1247 	if (get_user(val, ubufp))
1248 		return -EFAULT;
1249 
1250 	server = val & KVM_XICS_DESTINATION_MASK;
1251 	prio = val >> KVM_XICS_PRIORITY_SHIFT;
1252 	if (prio != MASKED &&
1253 	    kvmppc_xics_find_server(xics->kvm, server) == NULL)
1254 		return -EINVAL;
1255 
1256 	local_irq_save(flags);
1257 	arch_spin_lock(&ics->lock);
1258 	irqp->server = server;
1259 	irqp->saved_priority = prio;
1260 	if (val & KVM_XICS_MASKED)
1261 		prio = MASKED;
1262 	irqp->priority = prio;
1263 	irqp->resend = 0;
1264 	irqp->masked_pending = 0;
1265 	irqp->lsi = 0;
1266 	irqp->pq_state = 0;
1267 	if (val & KVM_XICS_LEVEL_SENSITIVE)
1268 		irqp->lsi = 1;
1269 	/* If PENDING, set P in case P is not saved because of old code */
1270 	if (val & KVM_XICS_PRESENTED || val & KVM_XICS_PENDING)
1271 		irqp->pq_state |= PQ_PRESENTED;
1272 	if (val & KVM_XICS_QUEUED)
1273 		irqp->pq_state |= PQ_QUEUED;
1274 	irqp->exists = 1;
1275 	arch_spin_unlock(&ics->lock);
1276 	local_irq_restore(flags);
1277 
1278 	if (val & KVM_XICS_PENDING)
1279 		icp_deliver_irq(xics, NULL, irqp->number, false);
1280 
1281 	return 0;
1282 }
1283 
kvmppc_xics_set_irq(struct kvm * kvm,int irq_source_id,u32 irq,int level,bool line_status)1284 int kvmppc_xics_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
1285 			bool line_status)
1286 {
1287 	struct kvmppc_xics *xics = kvm->arch.xics;
1288 
1289 	if (!xics)
1290 		return -ENODEV;
1291 	return ics_deliver_irq(xics, irq, level);
1292 }
1293 
xics_set_attr(struct kvm_device * dev,struct kvm_device_attr * attr)1294 static int xics_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
1295 {
1296 	struct kvmppc_xics *xics = dev->private;
1297 
1298 	switch (attr->group) {
1299 	case KVM_DEV_XICS_GRP_SOURCES:
1300 		return xics_set_source(xics, attr->attr, attr->addr);
1301 	}
1302 	return -ENXIO;
1303 }
1304 
xics_get_attr(struct kvm_device * dev,struct kvm_device_attr * attr)1305 static int xics_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
1306 {
1307 	struct kvmppc_xics *xics = dev->private;
1308 
1309 	switch (attr->group) {
1310 	case KVM_DEV_XICS_GRP_SOURCES:
1311 		return xics_get_source(xics, attr->attr, attr->addr);
1312 	}
1313 	return -ENXIO;
1314 }
1315 
xics_has_attr(struct kvm_device * dev,struct kvm_device_attr * attr)1316 static int xics_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
1317 {
1318 	switch (attr->group) {
1319 	case KVM_DEV_XICS_GRP_SOURCES:
1320 		if (attr->attr >= KVMPPC_XICS_FIRST_IRQ &&
1321 		    attr->attr < KVMPPC_XICS_NR_IRQS)
1322 			return 0;
1323 		break;
1324 	}
1325 	return -ENXIO;
1326 }
1327 
1328 /*
1329  * Called when device fd is closed. kvm->lock is held.
1330  */
kvmppc_xics_release(struct kvm_device * dev)1331 static void kvmppc_xics_release(struct kvm_device *dev)
1332 {
1333 	struct kvmppc_xics *xics = dev->private;
1334 	unsigned long i;
1335 	struct kvm *kvm = xics->kvm;
1336 	struct kvm_vcpu *vcpu;
1337 
1338 	pr_devel("Releasing xics device\n");
1339 
1340 	/*
1341 	 * Since this is the device release function, we know that
1342 	 * userspace does not have any open fd referring to the
1343 	 * device.  Therefore there can not be any of the device
1344 	 * attribute set/get functions being executed concurrently,
1345 	 * and similarly, the connect_vcpu and set/clr_mapped
1346 	 * functions also cannot be being executed.
1347 	 */
1348 
1349 	debugfs_remove(xics->dentry);
1350 
1351 	/*
1352 	 * We should clean up the vCPU interrupt presenters first.
1353 	 */
1354 	kvm_for_each_vcpu(i, vcpu, kvm) {
1355 		/*
1356 		 * Take vcpu->mutex to ensure that no one_reg get/set ioctl
1357 		 * (i.e. kvmppc_xics_[gs]et_icp) can be done concurrently.
1358 		 * Holding the vcpu->mutex also means that execution is
1359 		 * excluded for the vcpu until the ICP was freed. When the vcpu
1360 		 * can execute again, vcpu->arch.icp and vcpu->arch.irq_type
1361 		 * have been cleared and the vcpu will not be going into the
1362 		 * XICS code anymore.
1363 		 */
1364 		mutex_lock(&vcpu->mutex);
1365 		kvmppc_xics_free_icp(vcpu);
1366 		mutex_unlock(&vcpu->mutex);
1367 	}
1368 
1369 	if (kvm)
1370 		kvm->arch.xics = NULL;
1371 
1372 	for (i = 0; i <= xics->max_icsid; i++) {
1373 		kfree(xics->ics[i]);
1374 		xics->ics[i] = NULL;
1375 	}
1376 	/*
1377 	 * A reference of the kvmppc_xics pointer is now kept under
1378 	 * the xics_device pointer of the machine for reuse. It is
1379 	 * freed when the VM is destroyed for now until we fix all the
1380 	 * execution paths.
1381 	 */
1382 	kfree(dev);
1383 }
1384 
kvmppc_xics_get_device(struct kvm * kvm)1385 static struct kvmppc_xics *kvmppc_xics_get_device(struct kvm *kvm)
1386 {
1387 	struct kvmppc_xics **kvm_xics_device = &kvm->arch.xics_device;
1388 	struct kvmppc_xics *xics = *kvm_xics_device;
1389 
1390 	if (!xics) {
1391 		xics = kzalloc(sizeof(*xics), GFP_KERNEL);
1392 		*kvm_xics_device = xics;
1393 	} else {
1394 		memset(xics, 0, sizeof(*xics));
1395 	}
1396 
1397 	return xics;
1398 }
1399 
kvmppc_xics_create(struct kvm_device * dev,u32 type)1400 static int kvmppc_xics_create(struct kvm_device *dev, u32 type)
1401 {
1402 	struct kvmppc_xics *xics;
1403 	struct kvm *kvm = dev->kvm;
1404 
1405 	pr_devel("Creating xics for partition\n");
1406 
1407 	/* Already there ? */
1408 	if (kvm->arch.xics)
1409 		return -EEXIST;
1410 
1411 	xics = kvmppc_xics_get_device(kvm);
1412 	if (!xics)
1413 		return -ENOMEM;
1414 
1415 	dev->private = xics;
1416 	xics->dev = dev;
1417 	xics->kvm = kvm;
1418 	kvm->arch.xics = xics;
1419 
1420 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
1421 	if (cpu_has_feature(CPU_FTR_ARCH_206) &&
1422 	    cpu_has_feature(CPU_FTR_HVMODE)) {
1423 		/* Enable real mode support */
1424 		xics->real_mode = ENABLE_REALMODE;
1425 		xics->real_mode_dbg = DEBUG_REALMODE;
1426 	}
1427 #endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
1428 
1429 	return 0;
1430 }
1431 
kvmppc_xics_init(struct kvm_device * dev)1432 static void kvmppc_xics_init(struct kvm_device *dev)
1433 {
1434 	struct kvmppc_xics *xics = dev->private;
1435 
1436 	xics_debugfs_init(xics);
1437 }
1438 
1439 struct kvm_device_ops kvm_xics_ops = {
1440 	.name = "kvm-xics",
1441 	.create = kvmppc_xics_create,
1442 	.init = kvmppc_xics_init,
1443 	.release = kvmppc_xics_release,
1444 	.set_attr = xics_set_attr,
1445 	.get_attr = xics_get_attr,
1446 	.has_attr = xics_has_attr,
1447 };
1448 
kvmppc_xics_connect_vcpu(struct kvm_device * dev,struct kvm_vcpu * vcpu,u32 xcpu)1449 int kvmppc_xics_connect_vcpu(struct kvm_device *dev, struct kvm_vcpu *vcpu,
1450 			     u32 xcpu)
1451 {
1452 	struct kvmppc_xics *xics = dev->private;
1453 	int r = -EBUSY;
1454 
1455 	if (dev->ops != &kvm_xics_ops)
1456 		return -EPERM;
1457 	if (xics->kvm != vcpu->kvm)
1458 		return -EPERM;
1459 	if (vcpu->arch.irq_type != KVMPPC_IRQ_DEFAULT)
1460 		return -EBUSY;
1461 
1462 	r = kvmppc_xics_create_icp(vcpu, xcpu);
1463 	if (!r)
1464 		vcpu->arch.irq_type = KVMPPC_IRQ_XICS;
1465 
1466 	return r;
1467 }
1468 
kvmppc_xics_free_icp(struct kvm_vcpu * vcpu)1469 void kvmppc_xics_free_icp(struct kvm_vcpu *vcpu)
1470 {
1471 	if (!vcpu->arch.icp)
1472 		return;
1473 	kfree(vcpu->arch.icp);
1474 	vcpu->arch.icp = NULL;
1475 	vcpu->arch.irq_type = KVMPPC_IRQ_DEFAULT;
1476 }
1477 
kvmppc_xics_set_mapped(struct kvm * kvm,unsigned long irq,unsigned long host_irq)1478 void kvmppc_xics_set_mapped(struct kvm *kvm, unsigned long irq,
1479 			    unsigned long host_irq)
1480 {
1481 	struct kvmppc_xics *xics = kvm->arch.xics;
1482 	struct kvmppc_ics *ics;
1483 	u16 idx;
1484 
1485 	ics = kvmppc_xics_find_ics(xics, irq, &idx);
1486 	if (!ics)
1487 		return;
1488 
1489 	ics->irq_state[idx].host_irq = host_irq;
1490 	ics->irq_state[idx].intr_cpu = -1;
1491 }
1492 EXPORT_SYMBOL_GPL(kvmppc_xics_set_mapped);
1493 
kvmppc_xics_clr_mapped(struct kvm * kvm,unsigned long irq,unsigned long host_irq)1494 void kvmppc_xics_clr_mapped(struct kvm *kvm, unsigned long irq,
1495 			    unsigned long host_irq)
1496 {
1497 	struct kvmppc_xics *xics = kvm->arch.xics;
1498 	struct kvmppc_ics *ics;
1499 	u16 idx;
1500 
1501 	ics = kvmppc_xics_find_ics(xics, irq, &idx);
1502 	if (!ics)
1503 		return;
1504 
1505 	ics->irq_state[idx].host_irq = 0;
1506 }
1507 EXPORT_SYMBOL_GPL(kvmppc_xics_clr_mapped);
1508