1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/kernel.h>
3 #include <linux/kvm_host.h>
4 #include <asm/asm-prototypes.h>
5 #include <asm/dbell.h>
6 #include <asm/ppc-opcode.h>
7 
8 #include "book3s_hv.h"
9 
load_spr_state(struct kvm_vcpu * vcpu,struct p9_host_os_sprs * host_os_sprs)10 static void load_spr_state(struct kvm_vcpu *vcpu,
11 				struct p9_host_os_sprs *host_os_sprs)
12 {
13 	/* TAR is very fast */
14 	mtspr(SPRN_TAR, vcpu->arch.tar);
15 
16 #ifdef CONFIG_ALTIVEC
17 	if (cpu_has_feature(CPU_FTR_ALTIVEC) &&
18 	    current->thread.vrsave != vcpu->arch.vrsave)
19 		mtspr(SPRN_VRSAVE, vcpu->arch.vrsave);
20 #endif
21 
22 	if (vcpu->arch.hfscr & HFSCR_EBB) {
23 		if (current->thread.ebbhr != vcpu->arch.ebbhr)
24 			mtspr(SPRN_EBBHR, vcpu->arch.ebbhr);
25 		if (current->thread.ebbrr != vcpu->arch.ebbrr)
26 			mtspr(SPRN_EBBRR, vcpu->arch.ebbrr);
27 		if (current->thread.bescr != vcpu->arch.bescr)
28 			mtspr(SPRN_BESCR, vcpu->arch.bescr);
29 	}
30 
31 	if (cpu_has_feature(CPU_FTR_P9_TIDR) &&
32 			current->thread.tidr != vcpu->arch.tid)
33 		mtspr(SPRN_TIDR, vcpu->arch.tid);
34 	if (host_os_sprs->iamr != vcpu->arch.iamr)
35 		mtspr(SPRN_IAMR, vcpu->arch.iamr);
36 	if (host_os_sprs->amr != vcpu->arch.amr)
37 		mtspr(SPRN_AMR, vcpu->arch.amr);
38 	if (vcpu->arch.uamor != 0)
39 		mtspr(SPRN_UAMOR, vcpu->arch.uamor);
40 	if (current->thread.fscr != vcpu->arch.fscr)
41 		mtspr(SPRN_FSCR, vcpu->arch.fscr);
42 	if (current->thread.dscr != vcpu->arch.dscr)
43 		mtspr(SPRN_DSCR, vcpu->arch.dscr);
44 	if (vcpu->arch.pspb != 0)
45 		mtspr(SPRN_PSPB, vcpu->arch.pspb);
46 
47 	/*
48 	 * DAR, DSISR, and for nested HV, SPRGs must be set with MSR[RI]
49 	 * clear (or hstate set appropriately to catch those registers
50 	 * being clobbered if we take a MCE or SRESET), so those are done
51 	 * later.
52 	 */
53 
54 	if (!(vcpu->arch.ctrl & 1))
55 		mtspr(SPRN_CTRLT, 0);
56 }
57 
store_spr_state(struct kvm_vcpu * vcpu)58 static void store_spr_state(struct kvm_vcpu *vcpu)
59 {
60 	vcpu->arch.tar = mfspr(SPRN_TAR);
61 
62 #ifdef CONFIG_ALTIVEC
63 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
64 		vcpu->arch.vrsave = mfspr(SPRN_VRSAVE);
65 #endif
66 
67 	if (vcpu->arch.hfscr & HFSCR_EBB) {
68 		vcpu->arch.ebbhr = mfspr(SPRN_EBBHR);
69 		vcpu->arch.ebbrr = mfspr(SPRN_EBBRR);
70 		vcpu->arch.bescr = mfspr(SPRN_BESCR);
71 	}
72 
73 	if (cpu_has_feature(CPU_FTR_P9_TIDR))
74 		vcpu->arch.tid = mfspr(SPRN_TIDR);
75 	vcpu->arch.iamr = mfspr(SPRN_IAMR);
76 	vcpu->arch.amr = mfspr(SPRN_AMR);
77 	vcpu->arch.uamor = mfspr(SPRN_UAMOR);
78 	vcpu->arch.fscr = mfspr(SPRN_FSCR);
79 	vcpu->arch.dscr = mfspr(SPRN_DSCR);
80 	vcpu->arch.pspb = mfspr(SPRN_PSPB);
81 
82 	vcpu->arch.ctrl = mfspr(SPRN_CTRLF);
83 }
84 
85 /* Returns true if current MSR and/or guest MSR may have changed */
load_vcpu_state(struct kvm_vcpu * vcpu,struct p9_host_os_sprs * host_os_sprs)86 bool load_vcpu_state(struct kvm_vcpu *vcpu,
87 		     struct p9_host_os_sprs *host_os_sprs)
88 {
89 	bool ret = false;
90 
91 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
92 	if (cpu_has_feature(CPU_FTR_TM) ||
93 	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) {
94 		unsigned long guest_msr = vcpu->arch.shregs.msr;
95 		if (MSR_TM_ACTIVE(guest_msr)) {
96 			kvmppc_restore_tm_hv(vcpu, guest_msr, true);
97 			ret = true;
98 		} else if (vcpu->arch.hfscr & HFSCR_TM) {
99 			mtspr(SPRN_TEXASR, vcpu->arch.texasr);
100 			mtspr(SPRN_TFHAR, vcpu->arch.tfhar);
101 			mtspr(SPRN_TFIAR, vcpu->arch.tfiar);
102 		}
103 	}
104 #endif
105 
106 	load_spr_state(vcpu, host_os_sprs);
107 
108 	load_fp_state(&vcpu->arch.fp);
109 #ifdef CONFIG_ALTIVEC
110 	load_vr_state(&vcpu->arch.vr);
111 #endif
112 
113 	return ret;
114 }
115 EXPORT_SYMBOL_GPL(load_vcpu_state);
116 
store_vcpu_state(struct kvm_vcpu * vcpu)117 void store_vcpu_state(struct kvm_vcpu *vcpu)
118 {
119 	store_spr_state(vcpu);
120 
121 	store_fp_state(&vcpu->arch.fp);
122 #ifdef CONFIG_ALTIVEC
123 	store_vr_state(&vcpu->arch.vr);
124 #endif
125 
126 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
127 	if (cpu_has_feature(CPU_FTR_TM) ||
128 	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) {
129 		unsigned long guest_msr = vcpu->arch.shregs.msr;
130 		if (MSR_TM_ACTIVE(guest_msr)) {
131 			kvmppc_save_tm_hv(vcpu, guest_msr, true);
132 		} else if (vcpu->arch.hfscr & HFSCR_TM) {
133 			vcpu->arch.texasr = mfspr(SPRN_TEXASR);
134 			vcpu->arch.tfhar = mfspr(SPRN_TFHAR);
135 			vcpu->arch.tfiar = mfspr(SPRN_TFIAR);
136 
137 			if (!vcpu->arch.nested) {
138 				vcpu->arch.load_tm++; /* see load_ebb comment */
139 				if (!vcpu->arch.load_tm)
140 					vcpu->arch.hfscr &= ~HFSCR_TM;
141 			}
142 		}
143 	}
144 #endif
145 }
146 EXPORT_SYMBOL_GPL(store_vcpu_state);
147 
save_p9_host_os_sprs(struct p9_host_os_sprs * host_os_sprs)148 void save_p9_host_os_sprs(struct p9_host_os_sprs *host_os_sprs)
149 {
150 	host_os_sprs->iamr = mfspr(SPRN_IAMR);
151 	host_os_sprs->amr = mfspr(SPRN_AMR);
152 }
153 EXPORT_SYMBOL_GPL(save_p9_host_os_sprs);
154 
155 /* vcpu guest regs must already be saved */
restore_p9_host_os_sprs(struct kvm_vcpu * vcpu,struct p9_host_os_sprs * host_os_sprs)156 void restore_p9_host_os_sprs(struct kvm_vcpu *vcpu,
157 			     struct p9_host_os_sprs *host_os_sprs)
158 {
159 	/*
160 	 * current->thread.xxx registers must all be restored to host
161 	 * values before a potential context switch, otherwise the context
162 	 * switch itself will overwrite current->thread.xxx with the values
163 	 * from the guest SPRs.
164 	 */
165 
166 	mtspr(SPRN_SPRG_VDSO_WRITE, local_paca->sprg_vdso);
167 
168 	if (cpu_has_feature(CPU_FTR_P9_TIDR) &&
169 			current->thread.tidr != vcpu->arch.tid)
170 		mtspr(SPRN_TIDR, current->thread.tidr);
171 	if (host_os_sprs->iamr != vcpu->arch.iamr)
172 		mtspr(SPRN_IAMR, host_os_sprs->iamr);
173 	if (vcpu->arch.uamor != 0)
174 		mtspr(SPRN_UAMOR, 0);
175 	if (host_os_sprs->amr != vcpu->arch.amr)
176 		mtspr(SPRN_AMR, host_os_sprs->amr);
177 	if (current->thread.fscr != vcpu->arch.fscr)
178 		mtspr(SPRN_FSCR, current->thread.fscr);
179 	if (current->thread.dscr != vcpu->arch.dscr)
180 		mtspr(SPRN_DSCR, current->thread.dscr);
181 	if (vcpu->arch.pspb != 0)
182 		mtspr(SPRN_PSPB, 0);
183 
184 	/* Save guest CTRL register, set runlatch to 1 */
185 	if (!(vcpu->arch.ctrl & 1))
186 		mtspr(SPRN_CTRLT, 1);
187 
188 #ifdef CONFIG_ALTIVEC
189 	if (cpu_has_feature(CPU_FTR_ALTIVEC) &&
190 	    vcpu->arch.vrsave != current->thread.vrsave)
191 		mtspr(SPRN_VRSAVE, current->thread.vrsave);
192 #endif
193 	if (vcpu->arch.hfscr & HFSCR_EBB) {
194 		if (vcpu->arch.bescr != current->thread.bescr)
195 			mtspr(SPRN_BESCR, current->thread.bescr);
196 		if (vcpu->arch.ebbhr != current->thread.ebbhr)
197 			mtspr(SPRN_EBBHR, current->thread.ebbhr);
198 		if (vcpu->arch.ebbrr != current->thread.ebbrr)
199 			mtspr(SPRN_EBBRR, current->thread.ebbrr);
200 
201 		if (!vcpu->arch.nested) {
202 			/*
203 			 * This is like load_fp in context switching, turn off
204 			 * the facility after it wraps the u8 to try avoiding
205 			 * saving and restoring the registers each partition
206 			 * switch.
207 			 */
208 			vcpu->arch.load_ebb++;
209 			if (!vcpu->arch.load_ebb)
210 				vcpu->arch.hfscr &= ~HFSCR_EBB;
211 		}
212 	}
213 
214 	if (vcpu->arch.tar != current->thread.tar)
215 		mtspr(SPRN_TAR, current->thread.tar);
216 }
217 EXPORT_SYMBOL_GPL(restore_p9_host_os_sprs);
218 
219 #ifdef CONFIG_KVM_BOOK3S_HV_P9_TIMING
accumulate_time(struct kvm_vcpu * vcpu,struct kvmhv_tb_accumulator * next)220 void accumulate_time(struct kvm_vcpu *vcpu, struct kvmhv_tb_accumulator *next)
221 {
222 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
223 	struct kvmhv_tb_accumulator *curr;
224 	u64 tb = mftb() - vc->tb_offset_applied;
225 	u64 prev_tb;
226 	u64 delta;
227 	u64 seq;
228 
229 	curr = vcpu->arch.cur_activity;
230 	vcpu->arch.cur_activity = next;
231 	prev_tb = vcpu->arch.cur_tb_start;
232 	vcpu->arch.cur_tb_start = tb;
233 
234 	if (!curr)
235 		return;
236 
237 	delta = tb - prev_tb;
238 
239 	seq = curr->seqcount;
240 	curr->seqcount = seq + 1;
241 	smp_wmb();
242 	curr->tb_total += delta;
243 	if (seq == 0 || delta < curr->tb_min)
244 		curr->tb_min = delta;
245 	if (delta > curr->tb_max)
246 		curr->tb_max = delta;
247 	smp_wmb();
248 	curr->seqcount = seq + 2;
249 }
250 EXPORT_SYMBOL_GPL(accumulate_time);
251 #endif
252 
mfslbv(unsigned int idx)253 static inline u64 mfslbv(unsigned int idx)
254 {
255 	u64 slbev;
256 
257 	asm volatile("slbmfev  %0,%1" : "=r" (slbev) : "r" (idx));
258 
259 	return slbev;
260 }
261 
mfslbe(unsigned int idx)262 static inline u64 mfslbe(unsigned int idx)
263 {
264 	u64 slbee;
265 
266 	asm volatile("slbmfee  %0,%1" : "=r" (slbee) : "r" (idx));
267 
268 	return slbee;
269 }
270 
mtslb(u64 slbee,u64 slbev)271 static inline void mtslb(u64 slbee, u64 slbev)
272 {
273 	asm volatile("slbmte %0,%1" :: "r" (slbev), "r" (slbee));
274 }
275 
clear_slb_entry(unsigned int idx)276 static inline void clear_slb_entry(unsigned int idx)
277 {
278 	mtslb(idx, 0);
279 }
280 
slb_clear_invalidate_partition(void)281 static inline void slb_clear_invalidate_partition(void)
282 {
283 	clear_slb_entry(0);
284 	asm volatile(PPC_SLBIA(6));
285 }
286 
287 /*
288  * Malicious or buggy radix guests may have inserted SLB entries
289  * (only 0..3 because radix always runs with UPRT=1), so these must
290  * be cleared here to avoid side-channels. slbmte is used rather
291  * than slbia, as it won't clear cached translations.
292  */
radix_clear_slb(void)293 static void radix_clear_slb(void)
294 {
295 	int i;
296 
297 	for (i = 0; i < 4; i++)
298 		clear_slb_entry(i);
299 }
300 
switch_mmu_to_guest_radix(struct kvm * kvm,struct kvm_vcpu * vcpu,u64 lpcr)301 static void switch_mmu_to_guest_radix(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
302 {
303 	struct kvm_nested_guest *nested = vcpu->arch.nested;
304 	u32 lpid;
305 	u32 pid;
306 
307 	lpid = nested ? nested->shadow_lpid : kvm->arch.lpid;
308 	pid = kvmppc_get_pid(vcpu);
309 
310 	/*
311 	 * Prior memory accesses to host PID Q3 must be completed before we
312 	 * start switching, and stores must be drained to avoid not-my-LPAR
313 	 * logic (see switch_mmu_to_host).
314 	 */
315 	asm volatile("hwsync" ::: "memory");
316 	isync();
317 	mtspr(SPRN_LPID, lpid);
318 	mtspr(SPRN_LPCR, lpcr);
319 	mtspr(SPRN_PID, pid);
320 	/*
321 	 * isync not required here because we are HRFID'ing to guest before
322 	 * any guest context access, which is context synchronising.
323 	 */
324 }
325 
switch_mmu_to_guest_hpt(struct kvm * kvm,struct kvm_vcpu * vcpu,u64 lpcr)326 static void switch_mmu_to_guest_hpt(struct kvm *kvm, struct kvm_vcpu *vcpu, u64 lpcr)
327 {
328 	u32 lpid;
329 	u32 pid;
330 	int i;
331 
332 	lpid = kvm->arch.lpid;
333 	pid = kvmppc_get_pid(vcpu);
334 
335 	/*
336 	 * See switch_mmu_to_guest_radix. ptesync should not be required here
337 	 * even if the host is in HPT mode because speculative accesses would
338 	 * not cause RC updates (we are in real mode).
339 	 */
340 	asm volatile("hwsync" ::: "memory");
341 	isync();
342 	mtspr(SPRN_LPID, lpid);
343 	mtspr(SPRN_LPCR, lpcr);
344 	mtspr(SPRN_PID, pid);
345 
346 	for (i = 0; i < vcpu->arch.slb_max; i++)
347 		mtslb(vcpu->arch.slb[i].orige, vcpu->arch.slb[i].origv);
348 	/*
349 	 * isync not required here, see switch_mmu_to_guest_radix.
350 	 */
351 }
352 
switch_mmu_to_host(struct kvm * kvm,u32 pid)353 static void switch_mmu_to_host(struct kvm *kvm, u32 pid)
354 {
355 	u32 lpid = kvm->arch.host_lpid;
356 	u64 lpcr = kvm->arch.host_lpcr;
357 
358 	/*
359 	 * The guest has exited, so guest MMU context is no longer being
360 	 * non-speculatively accessed, but a hwsync is needed before the
361 	 * mtLPIDR / mtPIDR switch, in order to ensure all stores are drained,
362 	 * so the not-my-LPAR tlbie logic does not overlook them.
363 	 */
364 	asm volatile("hwsync" ::: "memory");
365 	isync();
366 	mtspr(SPRN_PID, pid);
367 	mtspr(SPRN_LPID, lpid);
368 	mtspr(SPRN_LPCR, lpcr);
369 	/*
370 	 * isync is not required after the switch, because mtmsrd with L=0
371 	 * is performed after this switch, which is context synchronising.
372 	 */
373 
374 	if (!radix_enabled())
375 		slb_restore_bolted_realmode();
376 }
377 
save_clear_host_mmu(struct kvm * kvm)378 static void save_clear_host_mmu(struct kvm *kvm)
379 {
380 	if (!radix_enabled()) {
381 		/*
382 		 * Hash host could save and restore host SLB entries to
383 		 * reduce SLB fault overheads of VM exits, but for now the
384 		 * existing code clears all entries and restores just the
385 		 * bolted ones when switching back to host.
386 		 */
387 		slb_clear_invalidate_partition();
388 	}
389 }
390 
save_clear_guest_mmu(struct kvm * kvm,struct kvm_vcpu * vcpu)391 static void save_clear_guest_mmu(struct kvm *kvm, struct kvm_vcpu *vcpu)
392 {
393 	if (kvm_is_radix(kvm)) {
394 		radix_clear_slb();
395 	} else {
396 		int i;
397 		int nr = 0;
398 
399 		/*
400 		 * This must run before switching to host (radix host can't
401 		 * access all SLBs).
402 		 */
403 		for (i = 0; i < vcpu->arch.slb_nr; i++) {
404 			u64 slbee, slbev;
405 
406 			slbee = mfslbe(i);
407 			if (slbee & SLB_ESID_V) {
408 				slbev = mfslbv(i);
409 				vcpu->arch.slb[nr].orige = slbee | i;
410 				vcpu->arch.slb[nr].origv = slbev;
411 				nr++;
412 			}
413 		}
414 		vcpu->arch.slb_max = nr;
415 		slb_clear_invalidate_partition();
416 	}
417 }
418 
flush_guest_tlb(struct kvm * kvm)419 static void flush_guest_tlb(struct kvm *kvm)
420 {
421 	unsigned long rb, set;
422 
423 	rb = PPC_BIT(52);	/* IS = 2 */
424 	if (kvm_is_radix(kvm)) {
425 		/* R=1 PRS=1 RIC=2 */
426 		asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
427 			     : : "r" (rb), "i" (1), "i" (1), "i" (2),
428 			       "r" (0) : "memory");
429 		for (set = 1; set < kvm->arch.tlb_sets; ++set) {
430 			rb += PPC_BIT(51);	/* increment set number */
431 			/* R=1 PRS=1 RIC=0 */
432 			asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
433 				     : : "r" (rb), "i" (1), "i" (1), "i" (0),
434 				       "r" (0) : "memory");
435 		}
436 		asm volatile("ptesync": : :"memory");
437 		// POWER9 congruence-class TLBIEL leaves ERAT. Flush it now.
438 		asm volatile(PPC_RADIX_INVALIDATE_ERAT_GUEST : : :"memory");
439 	} else {
440 		for (set = 0; set < kvm->arch.tlb_sets; ++set) {
441 			/* R=0 PRS=0 RIC=0 */
442 			asm volatile(PPC_TLBIEL(%0, %4, %3, %2, %1)
443 				     : : "r" (rb), "i" (0), "i" (0), "i" (0),
444 				       "r" (0) : "memory");
445 			rb += PPC_BIT(51);	/* increment set number */
446 		}
447 		asm volatile("ptesync": : :"memory");
448 		// POWER9 congruence-class TLBIEL leaves ERAT. Flush it now.
449 		asm volatile(PPC_ISA_3_0_INVALIDATE_ERAT : : :"memory");
450 	}
451 }
452 
check_need_tlb_flush(struct kvm * kvm,int pcpu,struct kvm_nested_guest * nested)453 static void check_need_tlb_flush(struct kvm *kvm, int pcpu,
454 				 struct kvm_nested_guest *nested)
455 {
456 	cpumask_t *need_tlb_flush;
457 	bool all_set = true;
458 	int i;
459 
460 	if (nested)
461 		need_tlb_flush = &nested->need_tlb_flush;
462 	else
463 		need_tlb_flush = &kvm->arch.need_tlb_flush;
464 
465 	if (likely(!cpumask_test_cpu(pcpu, need_tlb_flush)))
466 		return;
467 
468 	/*
469 	 * Individual threads can come in here, but the TLB is shared between
470 	 * the 4 threads in a core, hence invalidating on one thread
471 	 * invalidates for all, so only invalidate the first time (if all bits
472 	 * were set.  The others must still execute a ptesync.
473 	 *
474 	 * If a race occurs and two threads do the TLB flush, that is not a
475 	 * problem, just sub-optimal.
476 	 */
477 	for (i = cpu_first_tlb_thread_sibling(pcpu);
478 			i <= cpu_last_tlb_thread_sibling(pcpu);
479 			i += cpu_tlb_thread_sibling_step()) {
480 		if (!cpumask_test_cpu(i, need_tlb_flush)) {
481 			all_set = false;
482 			break;
483 		}
484 	}
485 	if (all_set)
486 		flush_guest_tlb(kvm);
487 	else
488 		asm volatile("ptesync" ::: "memory");
489 
490 	/* Clear the bit after the TLB flush */
491 	cpumask_clear_cpu(pcpu, need_tlb_flush);
492 }
493 
kvmppc_msr_hard_disable_set_facilities(struct kvm_vcpu * vcpu,unsigned long msr)494 unsigned long kvmppc_msr_hard_disable_set_facilities(struct kvm_vcpu *vcpu, unsigned long msr)
495 {
496 	unsigned long msr_needed = 0;
497 
498 	msr &= ~MSR_EE;
499 
500 	/* MSR bits may have been cleared by context switch so must recheck */
501 	if (IS_ENABLED(CONFIG_PPC_FPU))
502 		msr_needed |= MSR_FP;
503 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
504 		msr_needed |= MSR_VEC;
505 	if (cpu_has_feature(CPU_FTR_VSX))
506 		msr_needed |= MSR_VSX;
507 	if ((cpu_has_feature(CPU_FTR_TM) ||
508 	    cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) &&
509 			(vcpu->arch.hfscr & HFSCR_TM))
510 		msr_needed |= MSR_TM;
511 
512 	/*
513 	 * This could be combined with MSR[RI] clearing, but that expands
514 	 * the unrecoverable window. It would be better to cover unrecoverable
515 	 * with KVM bad interrupt handling rather than use MSR[RI] at all.
516 	 *
517 	 * Much more difficult and less worthwhile to combine with IR/DR
518 	 * disable.
519 	 */
520 	if ((msr & msr_needed) != msr_needed) {
521 		msr |= msr_needed;
522 		__mtmsrd(msr, 0);
523 	} else {
524 		__hard_irq_disable();
525 	}
526 	local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
527 
528 	return msr;
529 }
530 EXPORT_SYMBOL_GPL(kvmppc_msr_hard_disable_set_facilities);
531 
kvmhv_vcpu_entry_p9(struct kvm_vcpu * vcpu,u64 time_limit,unsigned long lpcr,u64 * tb)532 int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr, u64 *tb)
533 {
534 	struct p9_host_os_sprs host_os_sprs;
535 	struct kvm *kvm = vcpu->kvm;
536 	struct kvm_nested_guest *nested = vcpu->arch.nested;
537 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
538 	s64 hdec, dec;
539 	u64 purr, spurr;
540 	u64 *exsave;
541 	int trap;
542 	unsigned long msr;
543 	unsigned long host_hfscr;
544 	unsigned long host_ciabr;
545 	unsigned long host_dawr0;
546 	unsigned long host_dawrx0;
547 	unsigned long host_psscr;
548 	unsigned long host_hpsscr;
549 	unsigned long host_pidr;
550 	unsigned long host_dawr1;
551 	unsigned long host_dawrx1;
552 	unsigned long dpdes;
553 
554 	hdec = time_limit - *tb;
555 	if (hdec < 0)
556 		return BOOK3S_INTERRUPT_HV_DECREMENTER;
557 
558 	WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_HV);
559 	WARN_ON_ONCE(!(vcpu->arch.shregs.msr & MSR_ME));
560 
561 	vcpu->arch.ceded = 0;
562 
563 	/* Save MSR for restore, with EE clear. */
564 	msr = mfmsr() & ~MSR_EE;
565 
566 	host_hfscr = mfspr(SPRN_HFSCR);
567 	host_ciabr = mfspr(SPRN_CIABR);
568 	host_psscr = mfspr(SPRN_PSSCR_PR);
569 	if (cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
570 		host_hpsscr = mfspr(SPRN_PSSCR);
571 	host_pidr = mfspr(SPRN_PID);
572 
573 	if (dawr_enabled()) {
574 		host_dawr0 = mfspr(SPRN_DAWR0);
575 		host_dawrx0 = mfspr(SPRN_DAWRX0);
576 		if (cpu_has_feature(CPU_FTR_DAWR1)) {
577 			host_dawr1 = mfspr(SPRN_DAWR1);
578 			host_dawrx1 = mfspr(SPRN_DAWRX1);
579 		}
580 	}
581 
582 	local_paca->kvm_hstate.host_purr = mfspr(SPRN_PURR);
583 	local_paca->kvm_hstate.host_spurr = mfspr(SPRN_SPURR);
584 
585 	save_p9_host_os_sprs(&host_os_sprs);
586 
587 	msr = kvmppc_msr_hard_disable_set_facilities(vcpu, msr);
588 	if (lazy_irq_pending()) {
589 		trap = 0;
590 		goto out;
591 	}
592 
593 	if (unlikely(load_vcpu_state(vcpu, &host_os_sprs)))
594 		msr = mfmsr(); /* MSR may have been updated */
595 
596 	if (vc->tb_offset) {
597 		u64 new_tb = *tb + vc->tb_offset;
598 		mtspr(SPRN_TBU40, new_tb);
599 		if ((mftb() & 0xffffff) < (new_tb & 0xffffff)) {
600 			new_tb += 0x1000000;
601 			mtspr(SPRN_TBU40, new_tb);
602 		}
603 		*tb = new_tb;
604 		vc->tb_offset_applied = vc->tb_offset;
605 	}
606 
607 	mtspr(SPRN_VTB, vc->vtb);
608 	mtspr(SPRN_PURR, vcpu->arch.purr);
609 	mtspr(SPRN_SPURR, vcpu->arch.spurr);
610 
611 	if (vc->pcr)
612 		mtspr(SPRN_PCR, vc->pcr | PCR_MASK);
613 	if (vcpu->arch.doorbell_request) {
614 		vcpu->arch.doorbell_request = 0;
615 		mtspr(SPRN_DPDES, 1);
616 	}
617 
618 	if (dawr_enabled()) {
619 		if (vcpu->arch.dawr0 != host_dawr0)
620 			mtspr(SPRN_DAWR0, vcpu->arch.dawr0);
621 		if (vcpu->arch.dawrx0 != host_dawrx0)
622 			mtspr(SPRN_DAWRX0, vcpu->arch.dawrx0);
623 		if (cpu_has_feature(CPU_FTR_DAWR1)) {
624 			if (vcpu->arch.dawr1 != host_dawr1)
625 				mtspr(SPRN_DAWR1, vcpu->arch.dawr1);
626 			if (vcpu->arch.dawrx1 != host_dawrx1)
627 				mtspr(SPRN_DAWRX1, vcpu->arch.dawrx1);
628 		}
629 	}
630 	if (vcpu->arch.ciabr != host_ciabr)
631 		mtspr(SPRN_CIABR, vcpu->arch.ciabr);
632 
633 
634 	if (cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) {
635 		mtspr(SPRN_PSSCR, vcpu->arch.psscr | PSSCR_EC |
636 		      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
637 	} else {
638 		if (vcpu->arch.psscr != host_psscr)
639 			mtspr(SPRN_PSSCR_PR, vcpu->arch.psscr);
640 	}
641 
642 	mtspr(SPRN_HFSCR, vcpu->arch.hfscr);
643 
644 	mtspr(SPRN_HSRR0, vcpu->arch.regs.nip);
645 	mtspr(SPRN_HSRR1, (vcpu->arch.shregs.msr & ~MSR_HV) | MSR_ME);
646 
647 	/*
648 	 * On POWER9 DD2.1 and below, sometimes on a Hypervisor Data Storage
649 	 * Interrupt (HDSI) the HDSISR is not be updated at all.
650 	 *
651 	 * To work around this we put a canary value into the HDSISR before
652 	 * returning to a guest and then check for this canary when we take a
653 	 * HDSI. If we find the canary on a HDSI, we know the hardware didn't
654 	 * update the HDSISR. In this case we return to the guest to retake the
655 	 * HDSI which should correctly update the HDSISR the second time HDSI
656 	 * entry.
657 	 *
658 	 * The "radix prefetch bug" test can be used to test for this bug, as
659 	 * it also exists fo DD2.1 and below.
660 	 */
661 	if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
662 		mtspr(SPRN_HDSISR, HDSISR_CANARY);
663 
664 	mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0);
665 	mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1);
666 	mtspr(SPRN_SPRG2, vcpu->arch.shregs.sprg2);
667 	mtspr(SPRN_SPRG3, vcpu->arch.shregs.sprg3);
668 
669 	/*
670 	 * It might be preferable to load_vcpu_state here, in order to get the
671 	 * GPR/FP register loads executing in parallel with the previous mtSPR
672 	 * instructions, but for now that can't be done because the TM handling
673 	 * in load_vcpu_state can change some SPRs and vcpu state (nip, msr).
674 	 * But TM could be split out if this would be a significant benefit.
675 	 */
676 
677 	/*
678 	 * MSR[RI] does not need to be cleared (and is not, for radix guests
679 	 * with no prefetch bug), because in_guest is set. If we take a SRESET
680 	 * or MCE with in_guest set but still in HV mode, then
681 	 * kvmppc_p9_bad_interrupt handles the interrupt, which effectively
682 	 * clears MSR[RI] and doesn't return.
683 	 */
684 	WRITE_ONCE(local_paca->kvm_hstate.in_guest, KVM_GUEST_MODE_HV_P9);
685 	barrier(); /* Open in_guest critical section */
686 
687 	/*
688 	 * Hash host, hash guest, or radix guest with prefetch bug, all have
689 	 * to disable the MMU before switching to guest MMU state.
690 	 */
691 	if (!radix_enabled() || !kvm_is_radix(kvm) ||
692 			cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG))
693 		__mtmsrd(msr & ~(MSR_IR|MSR_DR|MSR_RI), 0);
694 
695 	save_clear_host_mmu(kvm);
696 
697 	if (kvm_is_radix(kvm))
698 		switch_mmu_to_guest_radix(kvm, vcpu, lpcr);
699 	else
700 		switch_mmu_to_guest_hpt(kvm, vcpu, lpcr);
701 
702 	/* TLBIEL uses LPID=LPIDR, so run this after setting guest LPID */
703 	check_need_tlb_flush(kvm, vc->pcpu, nested);
704 
705 	/*
706 	 * P9 suppresses the HDEC exception when LPCR[HDICE] = 0,
707 	 * so set guest LPCR (with HDICE) before writing HDEC.
708 	 */
709 	mtspr(SPRN_HDEC, hdec);
710 
711 	mtspr(SPRN_DEC, vcpu->arch.dec_expires - *tb);
712 
713 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
714 tm_return_to_guest:
715 #endif
716 	mtspr(SPRN_DAR, vcpu->arch.shregs.dar);
717 	mtspr(SPRN_DSISR, vcpu->arch.shregs.dsisr);
718 	mtspr(SPRN_SRR0, vcpu->arch.shregs.srr0);
719 	mtspr(SPRN_SRR1, vcpu->arch.shregs.srr1);
720 
721 	switch_pmu_to_guest(vcpu, &host_os_sprs);
722 	accumulate_time(vcpu, &vcpu->arch.in_guest);
723 
724 	kvmppc_p9_enter_guest(vcpu);
725 
726 	accumulate_time(vcpu, &vcpu->arch.guest_exit);
727 	switch_pmu_to_host(vcpu, &host_os_sprs);
728 
729 	/* XXX: Could get these from r11/12 and paca exsave instead */
730 	vcpu->arch.shregs.srr0 = mfspr(SPRN_SRR0);
731 	vcpu->arch.shregs.srr1 = mfspr(SPRN_SRR1);
732 	vcpu->arch.shregs.dar = mfspr(SPRN_DAR);
733 	vcpu->arch.shregs.dsisr = mfspr(SPRN_DSISR);
734 
735 	/* 0x2 bit for HSRR is only used by PR and P7/8 HV paths, clear it */
736 	trap = local_paca->kvm_hstate.scratch0 & ~0x2;
737 
738 	if (likely(trap > BOOK3S_INTERRUPT_MACHINE_CHECK))
739 		exsave = local_paca->exgen;
740 	else if (trap == BOOK3S_INTERRUPT_SYSTEM_RESET)
741 		exsave = local_paca->exnmi;
742 	else /* trap == 0x200 */
743 		exsave = local_paca->exmc;
744 
745 	vcpu->arch.regs.gpr[1] = local_paca->kvm_hstate.scratch1;
746 	vcpu->arch.regs.gpr[3] = local_paca->kvm_hstate.scratch2;
747 
748 	/*
749 	 * After reading machine check regs (DAR, DSISR, SRR0/1) and hstate
750 	 * scratch (which we need to move into exsave to make re-entrant vs
751 	 * SRESET/MCE), register state is protected from reentrancy. However
752 	 * timebase, MMU, among other state is still set to guest, so don't
753 	 * enable MSR[RI] here. It gets enabled at the end, after in_guest
754 	 * is cleared.
755 	 *
756 	 * It is possible an NMI could come in here, which is why it is
757 	 * important to save the above state early so it can be debugged.
758 	 */
759 
760 	vcpu->arch.regs.gpr[9] = exsave[EX_R9/sizeof(u64)];
761 	vcpu->arch.regs.gpr[10] = exsave[EX_R10/sizeof(u64)];
762 	vcpu->arch.regs.gpr[11] = exsave[EX_R11/sizeof(u64)];
763 	vcpu->arch.regs.gpr[12] = exsave[EX_R12/sizeof(u64)];
764 	vcpu->arch.regs.gpr[13] = exsave[EX_R13/sizeof(u64)];
765 	vcpu->arch.ppr = exsave[EX_PPR/sizeof(u64)];
766 	vcpu->arch.cfar = exsave[EX_CFAR/sizeof(u64)];
767 	vcpu->arch.regs.ctr = exsave[EX_CTR/sizeof(u64)];
768 
769 	vcpu->arch.last_inst = KVM_INST_FETCH_FAILED;
770 
771 	if (unlikely(trap == BOOK3S_INTERRUPT_MACHINE_CHECK)) {
772 		vcpu->arch.fault_dar = exsave[EX_DAR/sizeof(u64)];
773 		vcpu->arch.fault_dsisr = exsave[EX_DSISR/sizeof(u64)];
774 		kvmppc_realmode_machine_check(vcpu);
775 
776 	} else if (unlikely(trap == BOOK3S_INTERRUPT_HMI)) {
777 		kvmppc_p9_realmode_hmi_handler(vcpu);
778 
779 	} else if (trap == BOOK3S_INTERRUPT_H_EMUL_ASSIST) {
780 		vcpu->arch.emul_inst = mfspr(SPRN_HEIR);
781 
782 	} else if (trap == BOOK3S_INTERRUPT_H_DATA_STORAGE) {
783 		vcpu->arch.fault_dar = exsave[EX_DAR/sizeof(u64)];
784 		vcpu->arch.fault_dsisr = exsave[EX_DSISR/sizeof(u64)];
785 		vcpu->arch.fault_gpa = mfspr(SPRN_ASDR);
786 
787 	} else if (trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
788 		vcpu->arch.fault_gpa = mfspr(SPRN_ASDR);
789 
790 	} else if (trap == BOOK3S_INTERRUPT_H_FAC_UNAVAIL) {
791 		vcpu->arch.hfscr = mfspr(SPRN_HFSCR);
792 
793 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
794 	/*
795 	 * Softpatch interrupt for transactional memory emulation cases
796 	 * on POWER9 DD2.2.  This is early in the guest exit path - we
797 	 * haven't saved registers or done a treclaim yet.
798 	 */
799 	} else if (trap == BOOK3S_INTERRUPT_HV_SOFTPATCH) {
800 		vcpu->arch.emul_inst = mfspr(SPRN_HEIR);
801 
802 		/*
803 		 * The cases we want to handle here are those where the guest
804 		 * is in real suspend mode and is trying to transition to
805 		 * transactional mode.
806 		 */
807 		if (!local_paca->kvm_hstate.fake_suspend &&
808 				(vcpu->arch.shregs.msr & MSR_TS_S)) {
809 			if (kvmhv_p9_tm_emulation_early(vcpu)) {
810 				/*
811 				 * Go straight back into the guest with the
812 				 * new NIP/MSR as set by TM emulation.
813 				 */
814 				mtspr(SPRN_HSRR0, vcpu->arch.regs.nip);
815 				mtspr(SPRN_HSRR1, vcpu->arch.shregs.msr);
816 				goto tm_return_to_guest;
817 			}
818 		}
819 #endif
820 	}
821 
822 	/* Advance host PURR/SPURR by the amount used by guest */
823 	purr = mfspr(SPRN_PURR);
824 	spurr = mfspr(SPRN_SPURR);
825 	local_paca->kvm_hstate.host_purr += purr - vcpu->arch.purr;
826 	local_paca->kvm_hstate.host_spurr += spurr - vcpu->arch.spurr;
827 	vcpu->arch.purr = purr;
828 	vcpu->arch.spurr = spurr;
829 
830 	vcpu->arch.ic = mfspr(SPRN_IC);
831 	vcpu->arch.pid = mfspr(SPRN_PID);
832 	vcpu->arch.psscr = mfspr(SPRN_PSSCR_PR);
833 
834 	vcpu->arch.shregs.sprg0 = mfspr(SPRN_SPRG0);
835 	vcpu->arch.shregs.sprg1 = mfspr(SPRN_SPRG1);
836 	vcpu->arch.shregs.sprg2 = mfspr(SPRN_SPRG2);
837 	vcpu->arch.shregs.sprg3 = mfspr(SPRN_SPRG3);
838 
839 	dpdes = mfspr(SPRN_DPDES);
840 	if (dpdes)
841 		vcpu->arch.doorbell_request = 1;
842 
843 	vc->vtb = mfspr(SPRN_VTB);
844 
845 	dec = mfspr(SPRN_DEC);
846 	if (!(lpcr & LPCR_LD)) /* Sign extend if not using large decrementer */
847 		dec = (s32) dec;
848 	*tb = mftb();
849 	vcpu->arch.dec_expires = dec + *tb;
850 
851 	if (vc->tb_offset_applied) {
852 		u64 new_tb = *tb - vc->tb_offset_applied;
853 		mtspr(SPRN_TBU40, new_tb);
854 		if ((mftb() & 0xffffff) < (new_tb & 0xffffff)) {
855 			new_tb += 0x1000000;
856 			mtspr(SPRN_TBU40, new_tb);
857 		}
858 		*tb = new_tb;
859 		vc->tb_offset_applied = 0;
860 	}
861 
862 	save_clear_guest_mmu(kvm, vcpu);
863 	switch_mmu_to_host(kvm, host_pidr);
864 
865 	/*
866 	 * Enable MSR here in order to have facilities enabled to save
867 	 * guest registers. This enables MMU (if we were in realmode), so
868 	 * only switch MMU on after the MMU is switched to host, to avoid
869 	 * the P9_RADIX_PREFETCH_BUG or hash guest context.
870 	 */
871 	if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) &&
872 			vcpu->arch.shregs.msr & MSR_TS_MASK)
873 		msr |= MSR_TS_S;
874 	__mtmsrd(msr, 0);
875 
876 	store_vcpu_state(vcpu);
877 
878 	mtspr(SPRN_PURR, local_paca->kvm_hstate.host_purr);
879 	mtspr(SPRN_SPURR, local_paca->kvm_hstate.host_spurr);
880 
881 	if (cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) {
882 		/* Preserve PSSCR[FAKE_SUSPEND] until we've called kvmppc_save_tm_hv */
883 		mtspr(SPRN_PSSCR, host_hpsscr |
884 		      (local_paca->kvm_hstate.fake_suspend << PSSCR_FAKE_SUSPEND_LG));
885 	}
886 
887 	mtspr(SPRN_HFSCR, host_hfscr);
888 	if (vcpu->arch.ciabr != host_ciabr)
889 		mtspr(SPRN_CIABR, host_ciabr);
890 
891 	if (dawr_enabled()) {
892 		if (vcpu->arch.dawr0 != host_dawr0)
893 			mtspr(SPRN_DAWR0, host_dawr0);
894 		if (vcpu->arch.dawrx0 != host_dawrx0)
895 			mtspr(SPRN_DAWRX0, host_dawrx0);
896 		if (cpu_has_feature(CPU_FTR_DAWR1)) {
897 			if (vcpu->arch.dawr1 != host_dawr1)
898 				mtspr(SPRN_DAWR1, host_dawr1);
899 			if (vcpu->arch.dawrx1 != host_dawrx1)
900 				mtspr(SPRN_DAWRX1, host_dawrx1);
901 		}
902 	}
903 
904 	if (dpdes)
905 		mtspr(SPRN_DPDES, 0);
906 	if (vc->pcr)
907 		mtspr(SPRN_PCR, PCR_MASK);
908 
909 	/* HDEC must be at least as large as DEC, so decrementer_max fits */
910 	mtspr(SPRN_HDEC, decrementer_max);
911 
912 	timer_rearm_host_dec(*tb);
913 
914 	restore_p9_host_os_sprs(vcpu, &host_os_sprs);
915 
916 	barrier(); /* Close in_guest critical section */
917 	WRITE_ONCE(local_paca->kvm_hstate.in_guest, KVM_GUEST_MODE_NONE);
918 	/* Interrupts are recoverable at this point */
919 
920 	/*
921 	 * cp_abort is required if the processor supports local copy-paste
922 	 * to clear the copy buffer that was under control of the guest.
923 	 */
924 	if (cpu_has_feature(CPU_FTR_ARCH_31))
925 		asm volatile(PPC_CP_ABORT);
926 
927 out:
928 	return trap;
929 }
930 EXPORT_SYMBOL_GPL(kvmhv_vcpu_entry_p9);
931