1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright IBM Corporation, 2018
4  * Authors Suraj Jitindar Singh <sjitindarsingh@gmail.com>
5  *	   Paul Mackerras <paulus@ozlabs.org>
6  *
7  * Description: KVM functions specific to running nested KVM-HV guests
8  * on Book3S processors (specifically POWER9 and later).
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/kvm_host.h>
13 #include <linux/llist.h>
14 #include <linux/pgtable.h>
15 
16 #include <asm/kvm_ppc.h>
17 #include <asm/kvm_book3s.h>
18 #include <asm/mmu.h>
19 #include <asm/pgalloc.h>
20 #include <asm/pte-walk.h>
21 #include <asm/reg.h>
22 #include <asm/plpar_wrappers.h>
23 #include <asm/firmware.h>
24 
25 static struct patb_entry *pseries_partition_tb;
26 
27 static void kvmhv_update_ptbl_cache(struct kvm_nested_guest *gp);
28 static void kvmhv_free_memslot_nest_rmap(struct kvm_memory_slot *free);
29 
30 void kvmhv_save_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr)
31 {
32 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
33 
34 	hr->pcr = vc->pcr | PCR_MASK;
35 	hr->dpdes = vc->dpdes;
36 	hr->hfscr = vcpu->arch.hfscr;
37 	hr->tb_offset = vc->tb_offset;
38 	hr->dawr0 = vcpu->arch.dawr0;
39 	hr->dawrx0 = vcpu->arch.dawrx0;
40 	hr->ciabr = vcpu->arch.ciabr;
41 	hr->purr = vcpu->arch.purr;
42 	hr->spurr = vcpu->arch.spurr;
43 	hr->ic = vcpu->arch.ic;
44 	hr->vtb = vc->vtb;
45 	hr->srr0 = vcpu->arch.shregs.srr0;
46 	hr->srr1 = vcpu->arch.shregs.srr1;
47 	hr->sprg[0] = vcpu->arch.shregs.sprg0;
48 	hr->sprg[1] = vcpu->arch.shregs.sprg1;
49 	hr->sprg[2] = vcpu->arch.shregs.sprg2;
50 	hr->sprg[3] = vcpu->arch.shregs.sprg3;
51 	hr->pidr = vcpu->arch.pid;
52 	hr->cfar = vcpu->arch.cfar;
53 	hr->ppr = vcpu->arch.ppr;
54 	hr->dawr1 = vcpu->arch.dawr1;
55 	hr->dawrx1 = vcpu->arch.dawrx1;
56 }
57 
58 /* Use noinline_for_stack due to https://bugs.llvm.org/show_bug.cgi?id=49610 */
59 static noinline_for_stack void byteswap_pt_regs(struct pt_regs *regs)
60 {
61 	unsigned long *addr = (unsigned long *) regs;
62 
63 	for (; addr < ((unsigned long *) (regs + 1)); addr++)
64 		*addr = swab64(*addr);
65 }
66 
67 static void byteswap_hv_regs(struct hv_guest_state *hr)
68 {
69 	hr->version = swab64(hr->version);
70 	hr->lpid = swab32(hr->lpid);
71 	hr->vcpu_token = swab32(hr->vcpu_token);
72 	hr->lpcr = swab64(hr->lpcr);
73 	hr->pcr = swab64(hr->pcr) | PCR_MASK;
74 	hr->amor = swab64(hr->amor);
75 	hr->dpdes = swab64(hr->dpdes);
76 	hr->hfscr = swab64(hr->hfscr);
77 	hr->tb_offset = swab64(hr->tb_offset);
78 	hr->dawr0 = swab64(hr->dawr0);
79 	hr->dawrx0 = swab64(hr->dawrx0);
80 	hr->ciabr = swab64(hr->ciabr);
81 	hr->hdec_expiry = swab64(hr->hdec_expiry);
82 	hr->purr = swab64(hr->purr);
83 	hr->spurr = swab64(hr->spurr);
84 	hr->ic = swab64(hr->ic);
85 	hr->vtb = swab64(hr->vtb);
86 	hr->hdar = swab64(hr->hdar);
87 	hr->hdsisr = swab64(hr->hdsisr);
88 	hr->heir = swab64(hr->heir);
89 	hr->asdr = swab64(hr->asdr);
90 	hr->srr0 = swab64(hr->srr0);
91 	hr->srr1 = swab64(hr->srr1);
92 	hr->sprg[0] = swab64(hr->sprg[0]);
93 	hr->sprg[1] = swab64(hr->sprg[1]);
94 	hr->sprg[2] = swab64(hr->sprg[2]);
95 	hr->sprg[3] = swab64(hr->sprg[3]);
96 	hr->pidr = swab64(hr->pidr);
97 	hr->cfar = swab64(hr->cfar);
98 	hr->ppr = swab64(hr->ppr);
99 	hr->dawr1 = swab64(hr->dawr1);
100 	hr->dawrx1 = swab64(hr->dawrx1);
101 }
102 
103 static void save_hv_return_state(struct kvm_vcpu *vcpu,
104 				 struct hv_guest_state *hr)
105 {
106 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
107 
108 	hr->dpdes = vc->dpdes;
109 	hr->purr = vcpu->arch.purr;
110 	hr->spurr = vcpu->arch.spurr;
111 	hr->ic = vcpu->arch.ic;
112 	hr->vtb = vc->vtb;
113 	hr->srr0 = vcpu->arch.shregs.srr0;
114 	hr->srr1 = vcpu->arch.shregs.srr1;
115 	hr->sprg[0] = vcpu->arch.shregs.sprg0;
116 	hr->sprg[1] = vcpu->arch.shregs.sprg1;
117 	hr->sprg[2] = vcpu->arch.shregs.sprg2;
118 	hr->sprg[3] = vcpu->arch.shregs.sprg3;
119 	hr->pidr = vcpu->arch.pid;
120 	hr->cfar = vcpu->arch.cfar;
121 	hr->ppr = vcpu->arch.ppr;
122 	switch (vcpu->arch.trap) {
123 	case BOOK3S_INTERRUPT_H_DATA_STORAGE:
124 		hr->hdar = vcpu->arch.fault_dar;
125 		hr->hdsisr = vcpu->arch.fault_dsisr;
126 		hr->asdr = vcpu->arch.fault_gpa;
127 		break;
128 	case BOOK3S_INTERRUPT_H_INST_STORAGE:
129 		hr->asdr = vcpu->arch.fault_gpa;
130 		break;
131 	case BOOK3S_INTERRUPT_H_FAC_UNAVAIL:
132 		hr->hfscr = ((~HFSCR_INTR_CAUSE & hr->hfscr) |
133 			     (HFSCR_INTR_CAUSE & vcpu->arch.hfscr));
134 		break;
135 	case BOOK3S_INTERRUPT_H_EMUL_ASSIST:
136 		hr->heir = vcpu->arch.emul_inst;
137 		break;
138 	}
139 }
140 
141 static void restore_hv_regs(struct kvm_vcpu *vcpu, const struct hv_guest_state *hr)
142 {
143 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
144 
145 	vc->pcr = hr->pcr | PCR_MASK;
146 	vc->dpdes = hr->dpdes;
147 	vcpu->arch.hfscr = hr->hfscr;
148 	vcpu->arch.dawr0 = hr->dawr0;
149 	vcpu->arch.dawrx0 = hr->dawrx0;
150 	vcpu->arch.ciabr = hr->ciabr;
151 	vcpu->arch.purr = hr->purr;
152 	vcpu->arch.spurr = hr->spurr;
153 	vcpu->arch.ic = hr->ic;
154 	vc->vtb = hr->vtb;
155 	vcpu->arch.shregs.srr0 = hr->srr0;
156 	vcpu->arch.shregs.srr1 = hr->srr1;
157 	vcpu->arch.shregs.sprg0 = hr->sprg[0];
158 	vcpu->arch.shregs.sprg1 = hr->sprg[1];
159 	vcpu->arch.shregs.sprg2 = hr->sprg[2];
160 	vcpu->arch.shregs.sprg3 = hr->sprg[3];
161 	vcpu->arch.pid = hr->pidr;
162 	vcpu->arch.cfar = hr->cfar;
163 	vcpu->arch.ppr = hr->ppr;
164 	vcpu->arch.dawr1 = hr->dawr1;
165 	vcpu->arch.dawrx1 = hr->dawrx1;
166 }
167 
168 void kvmhv_restore_hv_return_state(struct kvm_vcpu *vcpu,
169 				   struct hv_guest_state *hr)
170 {
171 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
172 
173 	vc->dpdes = hr->dpdes;
174 	vcpu->arch.hfscr = hr->hfscr;
175 	vcpu->arch.purr = hr->purr;
176 	vcpu->arch.spurr = hr->spurr;
177 	vcpu->arch.ic = hr->ic;
178 	vc->vtb = hr->vtb;
179 	vcpu->arch.fault_dar = hr->hdar;
180 	vcpu->arch.fault_dsisr = hr->hdsisr;
181 	vcpu->arch.fault_gpa = hr->asdr;
182 	vcpu->arch.emul_inst = hr->heir;
183 	vcpu->arch.shregs.srr0 = hr->srr0;
184 	vcpu->arch.shregs.srr1 = hr->srr1;
185 	vcpu->arch.shregs.sprg0 = hr->sprg[0];
186 	vcpu->arch.shregs.sprg1 = hr->sprg[1];
187 	vcpu->arch.shregs.sprg2 = hr->sprg[2];
188 	vcpu->arch.shregs.sprg3 = hr->sprg[3];
189 	vcpu->arch.pid = hr->pidr;
190 	vcpu->arch.cfar = hr->cfar;
191 	vcpu->arch.ppr = hr->ppr;
192 }
193 
194 static void kvmhv_nested_mmio_needed(struct kvm_vcpu *vcpu, u64 regs_ptr)
195 {
196 	/* No need to reflect the page fault to L1, we've handled it */
197 	vcpu->arch.trap = 0;
198 
199 	/*
200 	 * Since the L2 gprs have already been written back into L1 memory when
201 	 * we complete the mmio, store the L1 memory location of the L2 gpr
202 	 * being loaded into by the mmio so that the loaded value can be
203 	 * written there in kvmppc_complete_mmio_load()
204 	 */
205 	if (((vcpu->arch.io_gpr & KVM_MMIO_REG_EXT_MASK) == KVM_MMIO_REG_GPR)
206 	    && (vcpu->mmio_is_write == 0)) {
207 		vcpu->arch.nested_io_gpr = (gpa_t) regs_ptr +
208 					   offsetof(struct pt_regs,
209 						    gpr[vcpu->arch.io_gpr]);
210 		vcpu->arch.io_gpr = KVM_MMIO_REG_NESTED_GPR;
211 	}
212 }
213 
214 static int kvmhv_read_guest_state_and_regs(struct kvm_vcpu *vcpu,
215 					   struct hv_guest_state *l2_hv,
216 					   struct pt_regs *l2_regs,
217 					   u64 hv_ptr, u64 regs_ptr)
218 {
219 	int size;
220 
221 	if (kvm_vcpu_read_guest(vcpu, hv_ptr, &l2_hv->version,
222 				sizeof(l2_hv->version)))
223 		return -1;
224 
225 	if (kvmppc_need_byteswap(vcpu))
226 		l2_hv->version = swab64(l2_hv->version);
227 
228 	size = hv_guest_state_size(l2_hv->version);
229 	if (size < 0)
230 		return -1;
231 
232 	return kvm_vcpu_read_guest(vcpu, hv_ptr, l2_hv, size) ||
233 		kvm_vcpu_read_guest(vcpu, regs_ptr, l2_regs,
234 				    sizeof(struct pt_regs));
235 }
236 
237 static int kvmhv_write_guest_state_and_regs(struct kvm_vcpu *vcpu,
238 					    struct hv_guest_state *l2_hv,
239 					    struct pt_regs *l2_regs,
240 					    u64 hv_ptr, u64 regs_ptr)
241 {
242 	int size;
243 
244 	size = hv_guest_state_size(l2_hv->version);
245 	if (size < 0)
246 		return -1;
247 
248 	return kvm_vcpu_write_guest(vcpu, hv_ptr, l2_hv, size) ||
249 		kvm_vcpu_write_guest(vcpu, regs_ptr, l2_regs,
250 				     sizeof(struct pt_regs));
251 }
252 
253 static void load_l2_hv_regs(struct kvm_vcpu *vcpu,
254 			    const struct hv_guest_state *l2_hv,
255 			    const struct hv_guest_state *l1_hv, u64 *lpcr)
256 {
257 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
258 	u64 mask;
259 
260 	restore_hv_regs(vcpu, l2_hv);
261 
262 	/*
263 	 * Don't let L1 change LPCR bits for the L2 except these:
264 	 */
265 	mask = LPCR_DPFD | LPCR_ILE | LPCR_TC | LPCR_AIL | LPCR_LD | LPCR_MER;
266 
267 	/*
268 	 * Additional filtering is required depending on hardware
269 	 * and configuration.
270 	 */
271 	*lpcr = kvmppc_filter_lpcr_hv(vcpu->kvm,
272 				      (vc->lpcr & ~mask) | (*lpcr & mask));
273 
274 	/*
275 	 * Don't let L1 enable features for L2 which we don't allow for L1,
276 	 * but preserve the interrupt cause field.
277 	 */
278 	vcpu->arch.hfscr = l2_hv->hfscr & (HFSCR_INTR_CAUSE | vcpu->arch.hfscr_permitted);
279 
280 	/* Don't let data address watchpoint match in hypervisor state */
281 	vcpu->arch.dawrx0 = l2_hv->dawrx0 & ~DAWRX_HYP;
282 	vcpu->arch.dawrx1 = l2_hv->dawrx1 & ~DAWRX_HYP;
283 
284 	/* Don't let completed instruction address breakpt match in HV state */
285 	if ((l2_hv->ciabr & CIABR_PRIV) == CIABR_PRIV_HYPER)
286 		vcpu->arch.ciabr = l2_hv->ciabr & ~CIABR_PRIV;
287 }
288 
289 long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
290 {
291 	long int err, r;
292 	struct kvm_nested_guest *l2;
293 	struct pt_regs l2_regs, saved_l1_regs;
294 	struct hv_guest_state l2_hv = {0}, saved_l1_hv;
295 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
296 	u64 hv_ptr, regs_ptr;
297 	u64 hdec_exp, lpcr;
298 	s64 delta_purr, delta_spurr, delta_ic, delta_vtb;
299 
300 	if (vcpu->kvm->arch.l1_ptcr == 0)
301 		return H_NOT_AVAILABLE;
302 
303 	if (MSR_TM_TRANSACTIONAL(vcpu->arch.shregs.msr))
304 		return H_BAD_MODE;
305 
306 	/* copy parameters in */
307 	hv_ptr = kvmppc_get_gpr(vcpu, 4);
308 	regs_ptr = kvmppc_get_gpr(vcpu, 5);
309 	kvm_vcpu_srcu_read_lock(vcpu);
310 	err = kvmhv_read_guest_state_and_regs(vcpu, &l2_hv, &l2_regs,
311 					      hv_ptr, regs_ptr);
312 	kvm_vcpu_srcu_read_unlock(vcpu);
313 	if (err)
314 		return H_PARAMETER;
315 
316 	if (kvmppc_need_byteswap(vcpu))
317 		byteswap_hv_regs(&l2_hv);
318 	if (l2_hv.version > HV_GUEST_STATE_VERSION)
319 		return H_P2;
320 
321 	if (kvmppc_need_byteswap(vcpu))
322 		byteswap_pt_regs(&l2_regs);
323 	if (l2_hv.vcpu_token >= NR_CPUS)
324 		return H_PARAMETER;
325 
326 	/*
327 	 * L1 must have set up a suspended state to enter the L2 in a
328 	 * transactional state, and only in that case. These have to be
329 	 * filtered out here to prevent causing a TM Bad Thing in the
330 	 * host HRFID. We could synthesize a TM Bad Thing back to the L1
331 	 * here but there doesn't seem like much point.
332 	 */
333 	if (MSR_TM_SUSPENDED(vcpu->arch.shregs.msr)) {
334 		if (!MSR_TM_ACTIVE(l2_regs.msr))
335 			return H_BAD_MODE;
336 	} else {
337 		if (l2_regs.msr & MSR_TS_MASK)
338 			return H_BAD_MODE;
339 		if (WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_TS_MASK))
340 			return H_BAD_MODE;
341 	}
342 
343 	/* translate lpid */
344 	l2 = kvmhv_get_nested(vcpu->kvm, l2_hv.lpid, true);
345 	if (!l2)
346 		return H_PARAMETER;
347 	if (!l2->l1_gr_to_hr) {
348 		mutex_lock(&l2->tlb_lock);
349 		kvmhv_update_ptbl_cache(l2);
350 		mutex_unlock(&l2->tlb_lock);
351 	}
352 
353 	/* save l1 values of things */
354 	vcpu->arch.regs.msr = vcpu->arch.shregs.msr;
355 	saved_l1_regs = vcpu->arch.regs;
356 	kvmhv_save_hv_regs(vcpu, &saved_l1_hv);
357 
358 	/* convert TB values/offsets to host (L0) values */
359 	hdec_exp = l2_hv.hdec_expiry - vc->tb_offset;
360 	vc->tb_offset += l2_hv.tb_offset;
361 	vcpu->arch.dec_expires += l2_hv.tb_offset;
362 
363 	/* set L1 state to L2 state */
364 	vcpu->arch.nested = l2;
365 	vcpu->arch.nested_vcpu_id = l2_hv.vcpu_token;
366 	vcpu->arch.nested_hfscr = l2_hv.hfscr;
367 	vcpu->arch.regs = l2_regs;
368 
369 	/* Guest must always run with ME enabled, HV disabled. */
370 	vcpu->arch.shregs.msr = (vcpu->arch.regs.msr | MSR_ME) & ~MSR_HV;
371 
372 	lpcr = l2_hv.lpcr;
373 	load_l2_hv_regs(vcpu, &l2_hv, &saved_l1_hv, &lpcr);
374 
375 	vcpu->arch.ret = RESUME_GUEST;
376 	vcpu->arch.trap = 0;
377 	do {
378 		r = kvmhv_run_single_vcpu(vcpu, hdec_exp, lpcr);
379 	} while (is_kvmppc_resume_guest(r));
380 
381 	/* save L2 state for return */
382 	l2_regs = vcpu->arch.regs;
383 	l2_regs.msr = vcpu->arch.shregs.msr;
384 	delta_purr = vcpu->arch.purr - l2_hv.purr;
385 	delta_spurr = vcpu->arch.spurr - l2_hv.spurr;
386 	delta_ic = vcpu->arch.ic - l2_hv.ic;
387 	delta_vtb = vc->vtb - l2_hv.vtb;
388 	save_hv_return_state(vcpu, &l2_hv);
389 
390 	/* restore L1 state */
391 	vcpu->arch.nested = NULL;
392 	vcpu->arch.regs = saved_l1_regs;
393 	vcpu->arch.shregs.msr = saved_l1_regs.msr & ~MSR_TS_MASK;
394 	/* set L1 MSR TS field according to L2 transaction state */
395 	if (l2_regs.msr & MSR_TS_MASK)
396 		vcpu->arch.shregs.msr |= MSR_TS_S;
397 	vc->tb_offset = saved_l1_hv.tb_offset;
398 	/* XXX: is this always the same delta as saved_l1_hv.tb_offset? */
399 	vcpu->arch.dec_expires -= l2_hv.tb_offset;
400 	restore_hv_regs(vcpu, &saved_l1_hv);
401 	vcpu->arch.purr += delta_purr;
402 	vcpu->arch.spurr += delta_spurr;
403 	vcpu->arch.ic += delta_ic;
404 	vc->vtb += delta_vtb;
405 
406 	kvmhv_put_nested(l2);
407 
408 	/* copy l2_hv_state and regs back to guest */
409 	if (kvmppc_need_byteswap(vcpu)) {
410 		byteswap_hv_regs(&l2_hv);
411 		byteswap_pt_regs(&l2_regs);
412 	}
413 	kvm_vcpu_srcu_read_lock(vcpu);
414 	err = kvmhv_write_guest_state_and_regs(vcpu, &l2_hv, &l2_regs,
415 					       hv_ptr, regs_ptr);
416 	kvm_vcpu_srcu_read_unlock(vcpu);
417 	if (err)
418 		return H_AUTHORITY;
419 
420 	if (r == -EINTR)
421 		return H_INTERRUPT;
422 
423 	if (vcpu->mmio_needed) {
424 		kvmhv_nested_mmio_needed(vcpu, regs_ptr);
425 		return H_TOO_HARD;
426 	}
427 
428 	return vcpu->arch.trap;
429 }
430 
431 long kvmhv_nested_init(void)
432 {
433 	long int ptb_order;
434 	unsigned long ptcr;
435 	long rc;
436 
437 	if (!kvmhv_on_pseries())
438 		return 0;
439 	if (!radix_enabled())
440 		return -ENODEV;
441 
442 	/* Partition table entry is 1<<4 bytes in size, hence the 4. */
443 	ptb_order = KVM_MAX_NESTED_GUESTS_SHIFT + 4;
444 	/* Minimum partition table size is 1<<12 bytes */
445 	if (ptb_order < 12)
446 		ptb_order = 12;
447 	pseries_partition_tb = kmalloc(sizeof(struct patb_entry) << ptb_order,
448 				       GFP_KERNEL);
449 	if (!pseries_partition_tb) {
450 		pr_err("kvm-hv: failed to allocated nested partition table\n");
451 		return -ENOMEM;
452 	}
453 
454 	ptcr = __pa(pseries_partition_tb) | (ptb_order - 12);
455 	rc = plpar_hcall_norets(H_SET_PARTITION_TABLE, ptcr);
456 	if (rc != H_SUCCESS) {
457 		pr_err("kvm-hv: Parent hypervisor does not support nesting (rc=%ld)\n",
458 		       rc);
459 		kfree(pseries_partition_tb);
460 		pseries_partition_tb = NULL;
461 		return -ENODEV;
462 	}
463 
464 	return 0;
465 }
466 
467 void kvmhv_nested_exit(void)
468 {
469 	/*
470 	 * N.B. the kvmhv_on_pseries() test is there because it enables
471 	 * the compiler to remove the call to plpar_hcall_norets()
472 	 * when CONFIG_PPC_PSERIES=n.
473 	 */
474 	if (kvmhv_on_pseries() && pseries_partition_tb) {
475 		plpar_hcall_norets(H_SET_PARTITION_TABLE, 0);
476 		kfree(pseries_partition_tb);
477 		pseries_partition_tb = NULL;
478 	}
479 }
480 
481 static void kvmhv_flush_lpid(unsigned int lpid)
482 {
483 	long rc;
484 
485 	if (!kvmhv_on_pseries()) {
486 		radix__flush_all_lpid(lpid);
487 		return;
488 	}
489 
490 	if (!firmware_has_feature(FW_FEATURE_RPT_INVALIDATE))
491 		rc = plpar_hcall_norets(H_TLB_INVALIDATE, H_TLBIE_P1_ENC(2, 0, 1),
492 					lpid, TLBIEL_INVAL_SET_LPID);
493 	else
494 		rc = pseries_rpt_invalidate(lpid, H_RPTI_TARGET_CMMU,
495 					    H_RPTI_TYPE_NESTED |
496 					    H_RPTI_TYPE_TLB | H_RPTI_TYPE_PWC |
497 					    H_RPTI_TYPE_PAT,
498 					    H_RPTI_PAGE_ALL, 0, -1UL);
499 	if (rc)
500 		pr_err("KVM: TLB LPID invalidation hcall failed, rc=%ld\n", rc);
501 }
502 
503 void kvmhv_set_ptbl_entry(unsigned int lpid, u64 dw0, u64 dw1)
504 {
505 	if (!kvmhv_on_pseries()) {
506 		mmu_partition_table_set_entry(lpid, dw0, dw1, true);
507 		return;
508 	}
509 
510 	pseries_partition_tb[lpid].patb0 = cpu_to_be64(dw0);
511 	pseries_partition_tb[lpid].patb1 = cpu_to_be64(dw1);
512 	/* L0 will do the necessary barriers */
513 	kvmhv_flush_lpid(lpid);
514 }
515 
516 static void kvmhv_set_nested_ptbl(struct kvm_nested_guest *gp)
517 {
518 	unsigned long dw0;
519 
520 	dw0 = PATB_HR | radix__get_tree_size() |
521 		__pa(gp->shadow_pgtable) | RADIX_PGD_INDEX_SIZE;
522 	kvmhv_set_ptbl_entry(gp->shadow_lpid, dw0, gp->process_table);
523 }
524 
525 /*
526  * Handle the H_SET_PARTITION_TABLE hcall.
527  * r4 = guest real address of partition table + log_2(size) - 12
528  * (formatted as for the PTCR).
529  */
530 long kvmhv_set_partition_table(struct kvm_vcpu *vcpu)
531 {
532 	struct kvm *kvm = vcpu->kvm;
533 	unsigned long ptcr = kvmppc_get_gpr(vcpu, 4);
534 	int srcu_idx;
535 	long ret = H_SUCCESS;
536 
537 	srcu_idx = srcu_read_lock(&kvm->srcu);
538 	/* Check partition size and base address. */
539 	if ((ptcr & PRTS_MASK) + 12 - 4 > KVM_MAX_NESTED_GUESTS_SHIFT ||
540 	    !kvm_is_visible_gfn(vcpu->kvm, (ptcr & PRTB_MASK) >> PAGE_SHIFT))
541 		ret = H_PARAMETER;
542 	srcu_read_unlock(&kvm->srcu, srcu_idx);
543 	if (ret == H_SUCCESS)
544 		kvm->arch.l1_ptcr = ptcr;
545 
546 	return ret;
547 }
548 
549 /*
550  * Handle the H_COPY_TOFROM_GUEST hcall.
551  * r4 = L1 lpid of nested guest
552  * r5 = pid
553  * r6 = eaddr to access
554  * r7 = to buffer (L1 gpa)
555  * r8 = from buffer (L1 gpa)
556  * r9 = n bytes to copy
557  */
558 long kvmhv_copy_tofrom_guest_nested(struct kvm_vcpu *vcpu)
559 {
560 	struct kvm_nested_guest *gp;
561 	int l1_lpid = kvmppc_get_gpr(vcpu, 4);
562 	int pid = kvmppc_get_gpr(vcpu, 5);
563 	gva_t eaddr = kvmppc_get_gpr(vcpu, 6);
564 	gpa_t gp_to = (gpa_t) kvmppc_get_gpr(vcpu, 7);
565 	gpa_t gp_from = (gpa_t) kvmppc_get_gpr(vcpu, 8);
566 	void *buf;
567 	unsigned long n = kvmppc_get_gpr(vcpu, 9);
568 	bool is_load = !!gp_to;
569 	long rc;
570 
571 	if (gp_to && gp_from) /* One must be NULL to determine the direction */
572 		return H_PARAMETER;
573 
574 	if (eaddr & (0xFFFUL << 52))
575 		return H_PARAMETER;
576 
577 	buf = kzalloc(n, GFP_KERNEL | __GFP_NOWARN);
578 	if (!buf)
579 		return H_NO_MEM;
580 
581 	gp = kvmhv_get_nested(vcpu->kvm, l1_lpid, false);
582 	if (!gp) {
583 		rc = H_PARAMETER;
584 		goto out_free;
585 	}
586 
587 	mutex_lock(&gp->tlb_lock);
588 
589 	if (is_load) {
590 		/* Load from the nested guest into our buffer */
591 		rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid,
592 						     eaddr, buf, NULL, n);
593 		if (rc)
594 			goto not_found;
595 
596 		/* Write what was loaded into our buffer back to the L1 guest */
597 		kvm_vcpu_srcu_read_lock(vcpu);
598 		rc = kvm_vcpu_write_guest(vcpu, gp_to, buf, n);
599 		kvm_vcpu_srcu_read_unlock(vcpu);
600 		if (rc)
601 			goto not_found;
602 	} else {
603 		/* Load the data to be stored from the L1 guest into our buf */
604 		kvm_vcpu_srcu_read_lock(vcpu);
605 		rc = kvm_vcpu_read_guest(vcpu, gp_from, buf, n);
606 		kvm_vcpu_srcu_read_unlock(vcpu);
607 		if (rc)
608 			goto not_found;
609 
610 		/* Store from our buffer into the nested guest */
611 		rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid,
612 						     eaddr, NULL, buf, n);
613 		if (rc)
614 			goto not_found;
615 	}
616 
617 out_unlock:
618 	mutex_unlock(&gp->tlb_lock);
619 	kvmhv_put_nested(gp);
620 out_free:
621 	kfree(buf);
622 	return rc;
623 not_found:
624 	rc = H_NOT_FOUND;
625 	goto out_unlock;
626 }
627 
628 /*
629  * Reload the partition table entry for a guest.
630  * Caller must hold gp->tlb_lock.
631  */
632 static void kvmhv_update_ptbl_cache(struct kvm_nested_guest *gp)
633 {
634 	int ret;
635 	struct patb_entry ptbl_entry;
636 	unsigned long ptbl_addr;
637 	struct kvm *kvm = gp->l1_host;
638 
639 	ret = -EFAULT;
640 	ptbl_addr = (kvm->arch.l1_ptcr & PRTB_MASK) + (gp->l1_lpid << 4);
641 	if (gp->l1_lpid < (1ul << ((kvm->arch.l1_ptcr & PRTS_MASK) + 12 - 4))) {
642 		int srcu_idx = srcu_read_lock(&kvm->srcu);
643 		ret = kvm_read_guest(kvm, ptbl_addr,
644 				     &ptbl_entry, sizeof(ptbl_entry));
645 		srcu_read_unlock(&kvm->srcu, srcu_idx);
646 	}
647 	if (ret) {
648 		gp->l1_gr_to_hr = 0;
649 		gp->process_table = 0;
650 	} else {
651 		gp->l1_gr_to_hr = be64_to_cpu(ptbl_entry.patb0);
652 		gp->process_table = be64_to_cpu(ptbl_entry.patb1);
653 	}
654 	kvmhv_set_nested_ptbl(gp);
655 }
656 
657 void kvmhv_vm_nested_init(struct kvm *kvm)
658 {
659 	idr_init(&kvm->arch.kvm_nested_guest_idr);
660 }
661 
662 static struct kvm_nested_guest *__find_nested(struct kvm *kvm, int lpid)
663 {
664 	return idr_find(&kvm->arch.kvm_nested_guest_idr, lpid);
665 }
666 
667 static bool __prealloc_nested(struct kvm *kvm, int lpid)
668 {
669 	if (idr_alloc(&kvm->arch.kvm_nested_guest_idr,
670 				NULL, lpid, lpid + 1, GFP_KERNEL) != lpid)
671 		return false;
672 	return true;
673 }
674 
675 static void __add_nested(struct kvm *kvm, int lpid, struct kvm_nested_guest *gp)
676 {
677 	if (idr_replace(&kvm->arch.kvm_nested_guest_idr, gp, lpid))
678 		WARN_ON(1);
679 }
680 
681 static void __remove_nested(struct kvm *kvm, int lpid)
682 {
683 	idr_remove(&kvm->arch.kvm_nested_guest_idr, lpid);
684 }
685 
686 static struct kvm_nested_guest *kvmhv_alloc_nested(struct kvm *kvm, unsigned int lpid)
687 {
688 	struct kvm_nested_guest *gp;
689 	long shadow_lpid;
690 
691 	gp = kzalloc(sizeof(*gp), GFP_KERNEL);
692 	if (!gp)
693 		return NULL;
694 	gp->l1_host = kvm;
695 	gp->l1_lpid = lpid;
696 	mutex_init(&gp->tlb_lock);
697 	gp->shadow_pgtable = pgd_alloc(kvm->mm);
698 	if (!gp->shadow_pgtable)
699 		goto out_free;
700 	shadow_lpid = kvmppc_alloc_lpid();
701 	if (shadow_lpid < 0)
702 		goto out_free2;
703 	gp->shadow_lpid = shadow_lpid;
704 	gp->radix = 1;
705 
706 	memset(gp->prev_cpu, -1, sizeof(gp->prev_cpu));
707 
708 	return gp;
709 
710  out_free2:
711 	pgd_free(kvm->mm, gp->shadow_pgtable);
712  out_free:
713 	kfree(gp);
714 	return NULL;
715 }
716 
717 /*
718  * Free up any resources allocated for a nested guest.
719  */
720 static void kvmhv_release_nested(struct kvm_nested_guest *gp)
721 {
722 	struct kvm *kvm = gp->l1_host;
723 
724 	if (gp->shadow_pgtable) {
725 		/*
726 		 * No vcpu is using this struct and no call to
727 		 * kvmhv_get_nested can find this struct,
728 		 * so we don't need to hold kvm->mmu_lock.
729 		 */
730 		kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable,
731 					  gp->shadow_lpid);
732 		pgd_free(kvm->mm, gp->shadow_pgtable);
733 	}
734 	kvmhv_set_ptbl_entry(gp->shadow_lpid, 0, 0);
735 	kvmppc_free_lpid(gp->shadow_lpid);
736 	kfree(gp);
737 }
738 
739 static void kvmhv_remove_nested(struct kvm_nested_guest *gp)
740 {
741 	struct kvm *kvm = gp->l1_host;
742 	int lpid = gp->l1_lpid;
743 	long ref;
744 
745 	spin_lock(&kvm->mmu_lock);
746 	if (gp == __find_nested(kvm, lpid)) {
747 		__remove_nested(kvm, lpid);
748 		--gp->refcnt;
749 	}
750 	ref = gp->refcnt;
751 	spin_unlock(&kvm->mmu_lock);
752 	if (ref == 0)
753 		kvmhv_release_nested(gp);
754 }
755 
756 /*
757  * Free up all nested resources allocated for this guest.
758  * This is called with no vcpus of the guest running, when
759  * switching the guest to HPT mode or when destroying the
760  * guest.
761  */
762 void kvmhv_release_all_nested(struct kvm *kvm)
763 {
764 	int lpid;
765 	struct kvm_nested_guest *gp;
766 	struct kvm_nested_guest *freelist = NULL;
767 	struct kvm_memory_slot *memslot;
768 	int srcu_idx, bkt;
769 
770 	spin_lock(&kvm->mmu_lock);
771 	idr_for_each_entry(&kvm->arch.kvm_nested_guest_idr, gp, lpid) {
772 		__remove_nested(kvm, lpid);
773 		if (--gp->refcnt == 0) {
774 			gp->next = freelist;
775 			freelist = gp;
776 		}
777 	}
778 	idr_destroy(&kvm->arch.kvm_nested_guest_idr);
779 	/* idr is empty and may be reused at this point */
780 	spin_unlock(&kvm->mmu_lock);
781 	while ((gp = freelist) != NULL) {
782 		freelist = gp->next;
783 		kvmhv_release_nested(gp);
784 	}
785 
786 	srcu_idx = srcu_read_lock(&kvm->srcu);
787 	kvm_for_each_memslot(memslot, bkt, kvm_memslots(kvm))
788 		kvmhv_free_memslot_nest_rmap(memslot);
789 	srcu_read_unlock(&kvm->srcu, srcu_idx);
790 }
791 
792 /* caller must hold gp->tlb_lock */
793 static void kvmhv_flush_nested(struct kvm_nested_guest *gp)
794 {
795 	struct kvm *kvm = gp->l1_host;
796 
797 	spin_lock(&kvm->mmu_lock);
798 	kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable, gp->shadow_lpid);
799 	spin_unlock(&kvm->mmu_lock);
800 	kvmhv_flush_lpid(gp->shadow_lpid);
801 	kvmhv_update_ptbl_cache(gp);
802 	if (gp->l1_gr_to_hr == 0)
803 		kvmhv_remove_nested(gp);
804 }
805 
806 struct kvm_nested_guest *kvmhv_get_nested(struct kvm *kvm, int l1_lpid,
807 					  bool create)
808 {
809 	struct kvm_nested_guest *gp, *newgp;
810 
811 	if (l1_lpid >= (1ul << ((kvm->arch.l1_ptcr & PRTS_MASK) + 12 - 4)))
812 		return NULL;
813 
814 	spin_lock(&kvm->mmu_lock);
815 	gp = __find_nested(kvm, l1_lpid);
816 	if (gp)
817 		++gp->refcnt;
818 	spin_unlock(&kvm->mmu_lock);
819 
820 	if (gp || !create)
821 		return gp;
822 
823 	newgp = kvmhv_alloc_nested(kvm, l1_lpid);
824 	if (!newgp)
825 		return NULL;
826 
827 	if (!__prealloc_nested(kvm, l1_lpid)) {
828 		kvmhv_release_nested(newgp);
829 		return NULL;
830 	}
831 
832 	spin_lock(&kvm->mmu_lock);
833 	gp = __find_nested(kvm, l1_lpid);
834 	if (!gp) {
835 		__add_nested(kvm, l1_lpid, newgp);
836 		++newgp->refcnt;
837 		gp = newgp;
838 		newgp = NULL;
839 	}
840 	++gp->refcnt;
841 	spin_unlock(&kvm->mmu_lock);
842 
843 	if (newgp)
844 		kvmhv_release_nested(newgp);
845 
846 	return gp;
847 }
848 
849 void kvmhv_put_nested(struct kvm_nested_guest *gp)
850 {
851 	struct kvm *kvm = gp->l1_host;
852 	long ref;
853 
854 	spin_lock(&kvm->mmu_lock);
855 	ref = --gp->refcnt;
856 	spin_unlock(&kvm->mmu_lock);
857 	if (ref == 0)
858 		kvmhv_release_nested(gp);
859 }
860 
861 pte_t *find_kvm_nested_guest_pte(struct kvm *kvm, unsigned long lpid,
862 				 unsigned long ea, unsigned *hshift)
863 {
864 	struct kvm_nested_guest *gp;
865 	pte_t *pte;
866 
867 	gp = __find_nested(kvm, lpid);
868 	if (!gp)
869 		return NULL;
870 
871 	VM_WARN(!spin_is_locked(&kvm->mmu_lock),
872 		"%s called with kvm mmu_lock not held \n", __func__);
873 	pte = __find_linux_pte(gp->shadow_pgtable, ea, NULL, hshift);
874 
875 	return pte;
876 }
877 
878 static inline bool kvmhv_n_rmap_is_equal(u64 rmap_1, u64 rmap_2)
879 {
880 	return !((rmap_1 ^ rmap_2) & (RMAP_NESTED_LPID_MASK |
881 				       RMAP_NESTED_GPA_MASK));
882 }
883 
884 void kvmhv_insert_nest_rmap(struct kvm *kvm, unsigned long *rmapp,
885 			    struct rmap_nested **n_rmap)
886 {
887 	struct llist_node *entry = ((struct llist_head *) rmapp)->first;
888 	struct rmap_nested *cursor;
889 	u64 rmap, new_rmap = (*n_rmap)->rmap;
890 
891 	/* Are there any existing entries? */
892 	if (!(*rmapp)) {
893 		/* No -> use the rmap as a single entry */
894 		*rmapp = new_rmap | RMAP_NESTED_IS_SINGLE_ENTRY;
895 		return;
896 	}
897 
898 	/* Do any entries match what we're trying to insert? */
899 	for_each_nest_rmap_safe(cursor, entry, &rmap) {
900 		if (kvmhv_n_rmap_is_equal(rmap, new_rmap))
901 			return;
902 	}
903 
904 	/* Do we need to create a list or just add the new entry? */
905 	rmap = *rmapp;
906 	if (rmap & RMAP_NESTED_IS_SINGLE_ENTRY) /* Not previously a list */
907 		*rmapp = 0UL;
908 	llist_add(&((*n_rmap)->list), (struct llist_head *) rmapp);
909 	if (rmap & RMAP_NESTED_IS_SINGLE_ENTRY) /* Not previously a list */
910 		(*n_rmap)->list.next = (struct llist_node *) rmap;
911 
912 	/* Set NULL so not freed by caller */
913 	*n_rmap = NULL;
914 }
915 
916 static void kvmhv_update_nest_rmap_rc(struct kvm *kvm, u64 n_rmap,
917 				      unsigned long clr, unsigned long set,
918 				      unsigned long hpa, unsigned long mask)
919 {
920 	unsigned long gpa;
921 	unsigned int shift, lpid;
922 	pte_t *ptep;
923 
924 	gpa = n_rmap & RMAP_NESTED_GPA_MASK;
925 	lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT;
926 
927 	/* Find the pte */
928 	ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
929 	/*
930 	 * If the pte is present and the pfn is still the same, update the pte.
931 	 * If the pfn has changed then this is a stale rmap entry, the nested
932 	 * gpa actually points somewhere else now, and there is nothing to do.
933 	 * XXX A future optimisation would be to remove the rmap entry here.
934 	 */
935 	if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa)) {
936 		__radix_pte_update(ptep, clr, set);
937 		kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid);
938 	}
939 }
940 
941 /*
942  * For a given list of rmap entries, update the rc bits in all ptes in shadow
943  * page tables for nested guests which are referenced by the rmap list.
944  */
945 void kvmhv_update_nest_rmap_rc_list(struct kvm *kvm, unsigned long *rmapp,
946 				    unsigned long clr, unsigned long set,
947 				    unsigned long hpa, unsigned long nbytes)
948 {
949 	struct llist_node *entry = ((struct llist_head *) rmapp)->first;
950 	struct rmap_nested *cursor;
951 	unsigned long rmap, mask;
952 
953 	if ((clr | set) & ~(_PAGE_DIRTY | _PAGE_ACCESSED))
954 		return;
955 
956 	mask = PTE_RPN_MASK & ~(nbytes - 1);
957 	hpa &= mask;
958 
959 	for_each_nest_rmap_safe(cursor, entry, &rmap)
960 		kvmhv_update_nest_rmap_rc(kvm, rmap, clr, set, hpa, mask);
961 }
962 
963 static void kvmhv_remove_nest_rmap(struct kvm *kvm, u64 n_rmap,
964 				   unsigned long hpa, unsigned long mask)
965 {
966 	struct kvm_nested_guest *gp;
967 	unsigned long gpa;
968 	unsigned int shift, lpid;
969 	pte_t *ptep;
970 
971 	gpa = n_rmap & RMAP_NESTED_GPA_MASK;
972 	lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT;
973 	gp = __find_nested(kvm, lpid);
974 	if (!gp)
975 		return;
976 
977 	/* Find and invalidate the pte */
978 	ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
979 	/* Don't spuriously invalidate ptes if the pfn has changed */
980 	if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa))
981 		kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid);
982 }
983 
984 static void kvmhv_remove_nest_rmap_list(struct kvm *kvm, unsigned long *rmapp,
985 					unsigned long hpa, unsigned long mask)
986 {
987 	struct llist_node *entry = llist_del_all((struct llist_head *) rmapp);
988 	struct rmap_nested *cursor;
989 	unsigned long rmap;
990 
991 	for_each_nest_rmap_safe(cursor, entry, &rmap) {
992 		kvmhv_remove_nest_rmap(kvm, rmap, hpa, mask);
993 		kfree(cursor);
994 	}
995 }
996 
997 /* called with kvm->mmu_lock held */
998 void kvmhv_remove_nest_rmap_range(struct kvm *kvm,
999 				  const struct kvm_memory_slot *memslot,
1000 				  unsigned long gpa, unsigned long hpa,
1001 				  unsigned long nbytes)
1002 {
1003 	unsigned long gfn, end_gfn;
1004 	unsigned long addr_mask;
1005 
1006 	if (!memslot)
1007 		return;
1008 	gfn = (gpa >> PAGE_SHIFT) - memslot->base_gfn;
1009 	end_gfn = gfn + (nbytes >> PAGE_SHIFT);
1010 
1011 	addr_mask = PTE_RPN_MASK & ~(nbytes - 1);
1012 	hpa &= addr_mask;
1013 
1014 	for (; gfn < end_gfn; gfn++) {
1015 		unsigned long *rmap = &memslot->arch.rmap[gfn];
1016 		kvmhv_remove_nest_rmap_list(kvm, rmap, hpa, addr_mask);
1017 	}
1018 }
1019 
1020 static void kvmhv_free_memslot_nest_rmap(struct kvm_memory_slot *free)
1021 {
1022 	unsigned long page;
1023 
1024 	for (page = 0; page < free->npages; page++) {
1025 		unsigned long rmap, *rmapp = &free->arch.rmap[page];
1026 		struct rmap_nested *cursor;
1027 		struct llist_node *entry;
1028 
1029 		entry = llist_del_all((struct llist_head *) rmapp);
1030 		for_each_nest_rmap_safe(cursor, entry, &rmap)
1031 			kfree(cursor);
1032 	}
1033 }
1034 
1035 static bool kvmhv_invalidate_shadow_pte(struct kvm_vcpu *vcpu,
1036 					struct kvm_nested_guest *gp,
1037 					long gpa, int *shift_ret)
1038 {
1039 	struct kvm *kvm = vcpu->kvm;
1040 	bool ret = false;
1041 	pte_t *ptep;
1042 	int shift;
1043 
1044 	spin_lock(&kvm->mmu_lock);
1045 	ptep = find_kvm_nested_guest_pte(kvm, gp->l1_lpid, gpa, &shift);
1046 	if (!shift)
1047 		shift = PAGE_SHIFT;
1048 	if (ptep && pte_present(*ptep)) {
1049 		kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid);
1050 		ret = true;
1051 	}
1052 	spin_unlock(&kvm->mmu_lock);
1053 
1054 	if (shift_ret)
1055 		*shift_ret = shift;
1056 	return ret;
1057 }
1058 
1059 static inline int get_ric(unsigned int instr)
1060 {
1061 	return (instr >> 18) & 0x3;
1062 }
1063 
1064 static inline int get_prs(unsigned int instr)
1065 {
1066 	return (instr >> 17) & 0x1;
1067 }
1068 
1069 static inline int get_r(unsigned int instr)
1070 {
1071 	return (instr >> 16) & 0x1;
1072 }
1073 
1074 static inline int get_lpid(unsigned long r_val)
1075 {
1076 	return r_val & 0xffffffff;
1077 }
1078 
1079 static inline int get_is(unsigned long r_val)
1080 {
1081 	return (r_val >> 10) & 0x3;
1082 }
1083 
1084 static inline int get_ap(unsigned long r_val)
1085 {
1086 	return (r_val >> 5) & 0x7;
1087 }
1088 
1089 static inline long get_epn(unsigned long r_val)
1090 {
1091 	return r_val >> 12;
1092 }
1093 
1094 static int kvmhv_emulate_tlbie_tlb_addr(struct kvm_vcpu *vcpu, int lpid,
1095 					int ap, long epn)
1096 {
1097 	struct kvm *kvm = vcpu->kvm;
1098 	struct kvm_nested_guest *gp;
1099 	long npages;
1100 	int shift, shadow_shift;
1101 	unsigned long addr;
1102 
1103 	shift = ap_to_shift(ap);
1104 	addr = epn << 12;
1105 	if (shift < 0)
1106 		/* Invalid ap encoding */
1107 		return -EINVAL;
1108 
1109 	addr &= ~((1UL << shift) - 1);
1110 	npages = 1UL << (shift - PAGE_SHIFT);
1111 
1112 	gp = kvmhv_get_nested(kvm, lpid, false);
1113 	if (!gp) /* No such guest -> nothing to do */
1114 		return 0;
1115 	mutex_lock(&gp->tlb_lock);
1116 
1117 	/* There may be more than one host page backing this single guest pte */
1118 	do {
1119 		kvmhv_invalidate_shadow_pte(vcpu, gp, addr, &shadow_shift);
1120 
1121 		npages -= 1UL << (shadow_shift - PAGE_SHIFT);
1122 		addr += 1UL << shadow_shift;
1123 	} while (npages > 0);
1124 
1125 	mutex_unlock(&gp->tlb_lock);
1126 	kvmhv_put_nested(gp);
1127 	return 0;
1128 }
1129 
1130 static void kvmhv_emulate_tlbie_lpid(struct kvm_vcpu *vcpu,
1131 				     struct kvm_nested_guest *gp, int ric)
1132 {
1133 	struct kvm *kvm = vcpu->kvm;
1134 
1135 	mutex_lock(&gp->tlb_lock);
1136 	switch (ric) {
1137 	case 0:
1138 		/* Invalidate TLB */
1139 		spin_lock(&kvm->mmu_lock);
1140 		kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable,
1141 					  gp->shadow_lpid);
1142 		kvmhv_flush_lpid(gp->shadow_lpid);
1143 		spin_unlock(&kvm->mmu_lock);
1144 		break;
1145 	case 1:
1146 		/*
1147 		 * Invalidate PWC
1148 		 * We don't cache this -> nothing to do
1149 		 */
1150 		break;
1151 	case 2:
1152 		/* Invalidate TLB, PWC and caching of partition table entries */
1153 		kvmhv_flush_nested(gp);
1154 		break;
1155 	default:
1156 		break;
1157 	}
1158 	mutex_unlock(&gp->tlb_lock);
1159 }
1160 
1161 static void kvmhv_emulate_tlbie_all_lpid(struct kvm_vcpu *vcpu, int ric)
1162 {
1163 	struct kvm *kvm = vcpu->kvm;
1164 	struct kvm_nested_guest *gp;
1165 	int lpid;
1166 
1167 	spin_lock(&kvm->mmu_lock);
1168 	idr_for_each_entry(&kvm->arch.kvm_nested_guest_idr, gp, lpid) {
1169 		spin_unlock(&kvm->mmu_lock);
1170 		kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
1171 		spin_lock(&kvm->mmu_lock);
1172 	}
1173 	spin_unlock(&kvm->mmu_lock);
1174 }
1175 
1176 static int kvmhv_emulate_priv_tlbie(struct kvm_vcpu *vcpu, unsigned int instr,
1177 				    unsigned long rsval, unsigned long rbval)
1178 {
1179 	struct kvm *kvm = vcpu->kvm;
1180 	struct kvm_nested_guest *gp;
1181 	int r, ric, prs, is, ap;
1182 	int lpid;
1183 	long epn;
1184 	int ret = 0;
1185 
1186 	ric = get_ric(instr);
1187 	prs = get_prs(instr);
1188 	r = get_r(instr);
1189 	lpid = get_lpid(rsval);
1190 	is = get_is(rbval);
1191 
1192 	/*
1193 	 * These cases are invalid and are not handled:
1194 	 * r   != 1 -> Only radix supported
1195 	 * prs == 1 -> Not HV privileged
1196 	 * ric == 3 -> No cluster bombs for radix
1197 	 * is  == 1 -> Partition scoped translations not associated with pid
1198 	 * (!is) && (ric == 1 || ric == 2) -> Not supported by ISA
1199 	 */
1200 	if ((!r) || (prs) || (ric == 3) || (is == 1) ||
1201 	    ((!is) && (ric == 1 || ric == 2)))
1202 		return -EINVAL;
1203 
1204 	switch (is) {
1205 	case 0:
1206 		/*
1207 		 * We know ric == 0
1208 		 * Invalidate TLB for a given target address
1209 		 */
1210 		epn = get_epn(rbval);
1211 		ap = get_ap(rbval);
1212 		ret = kvmhv_emulate_tlbie_tlb_addr(vcpu, lpid, ap, epn);
1213 		break;
1214 	case 2:
1215 		/* Invalidate matching LPID */
1216 		gp = kvmhv_get_nested(kvm, lpid, false);
1217 		if (gp) {
1218 			kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
1219 			kvmhv_put_nested(gp);
1220 		}
1221 		break;
1222 	case 3:
1223 		/* Invalidate ALL LPIDs */
1224 		kvmhv_emulate_tlbie_all_lpid(vcpu, ric);
1225 		break;
1226 	default:
1227 		ret = -EINVAL;
1228 		break;
1229 	}
1230 
1231 	return ret;
1232 }
1233 
1234 /*
1235  * This handles the H_TLB_INVALIDATE hcall.
1236  * Parameters are (r4) tlbie instruction code, (r5) rS contents,
1237  * (r6) rB contents.
1238  */
1239 long kvmhv_do_nested_tlbie(struct kvm_vcpu *vcpu)
1240 {
1241 	int ret;
1242 
1243 	ret = kvmhv_emulate_priv_tlbie(vcpu, kvmppc_get_gpr(vcpu, 4),
1244 			kvmppc_get_gpr(vcpu, 5), kvmppc_get_gpr(vcpu, 6));
1245 	if (ret)
1246 		return H_PARAMETER;
1247 	return H_SUCCESS;
1248 }
1249 
1250 static long do_tlb_invalidate_nested_all(struct kvm_vcpu *vcpu,
1251 					 unsigned long lpid, unsigned long ric)
1252 {
1253 	struct kvm *kvm = vcpu->kvm;
1254 	struct kvm_nested_guest *gp;
1255 
1256 	gp = kvmhv_get_nested(kvm, lpid, false);
1257 	if (gp) {
1258 		kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
1259 		kvmhv_put_nested(gp);
1260 	}
1261 	return H_SUCCESS;
1262 }
1263 
1264 /*
1265  * Number of pages above which we invalidate the entire LPID rather than
1266  * flush individual pages.
1267  */
1268 static unsigned long tlb_range_flush_page_ceiling __read_mostly = 33;
1269 
1270 static long do_tlb_invalidate_nested_tlb(struct kvm_vcpu *vcpu,
1271 					 unsigned long lpid,
1272 					 unsigned long pg_sizes,
1273 					 unsigned long start,
1274 					 unsigned long end)
1275 {
1276 	int ret = H_P4;
1277 	unsigned long addr, nr_pages;
1278 	struct mmu_psize_def *def;
1279 	unsigned long psize, ap, page_size;
1280 	bool flush_lpid;
1281 
1282 	for (psize = 0; psize < MMU_PAGE_COUNT; psize++) {
1283 		def = &mmu_psize_defs[psize];
1284 		if (!(pg_sizes & def->h_rpt_pgsize))
1285 			continue;
1286 
1287 		nr_pages = (end - start) >> def->shift;
1288 		flush_lpid = nr_pages > tlb_range_flush_page_ceiling;
1289 		if (flush_lpid)
1290 			return do_tlb_invalidate_nested_all(vcpu, lpid,
1291 							RIC_FLUSH_TLB);
1292 		addr = start;
1293 		ap = mmu_get_ap(psize);
1294 		page_size = 1UL << def->shift;
1295 		do {
1296 			ret = kvmhv_emulate_tlbie_tlb_addr(vcpu, lpid, ap,
1297 						   get_epn(addr));
1298 			if (ret)
1299 				return H_P4;
1300 			addr += page_size;
1301 		} while (addr < end);
1302 	}
1303 	return ret;
1304 }
1305 
1306 /*
1307  * Performs partition-scoped invalidations for nested guests
1308  * as part of H_RPT_INVALIDATE hcall.
1309  */
1310 long do_h_rpt_invalidate_pat(struct kvm_vcpu *vcpu, unsigned long lpid,
1311 			     unsigned long type, unsigned long pg_sizes,
1312 			     unsigned long start, unsigned long end)
1313 {
1314 	/*
1315 	 * If L2 lpid isn't valid, we need to return H_PARAMETER.
1316 	 *
1317 	 * However, nested KVM issues a L2 lpid flush call when creating
1318 	 * partition table entries for L2. This happens even before the
1319 	 * corresponding shadow lpid is created in HV which happens in
1320 	 * H_ENTER_NESTED call. Since we can't differentiate this case from
1321 	 * the invalid case, we ignore such flush requests and return success.
1322 	 */
1323 	if (!__find_nested(vcpu->kvm, lpid))
1324 		return H_SUCCESS;
1325 
1326 	/*
1327 	 * A flush all request can be handled by a full lpid flush only.
1328 	 */
1329 	if ((type & H_RPTI_TYPE_NESTED_ALL) == H_RPTI_TYPE_NESTED_ALL)
1330 		return do_tlb_invalidate_nested_all(vcpu, lpid, RIC_FLUSH_ALL);
1331 
1332 	/*
1333 	 * We don't need to handle a PWC flush like process table here,
1334 	 * because intermediate partition scoped table in nested guest doesn't
1335 	 * really have PWC. Only level we have PWC is in L0 and for nested
1336 	 * invalidate at L0 we always do kvm_flush_lpid() which does
1337 	 * radix__flush_all_lpid(). For range invalidate at any level, we
1338 	 * are not removing the higher level page tables and hence there is
1339 	 * no PWC invalidate needed.
1340 	 *
1341 	 * if (type & H_RPTI_TYPE_PWC) {
1342 	 *	ret = do_tlb_invalidate_nested_all(vcpu, lpid, RIC_FLUSH_PWC);
1343 	 *	if (ret)
1344 	 *		return H_P4;
1345 	 * }
1346 	 */
1347 
1348 	if (start == 0 && end == -1)
1349 		return do_tlb_invalidate_nested_all(vcpu, lpid, RIC_FLUSH_TLB);
1350 
1351 	if (type & H_RPTI_TYPE_TLB)
1352 		return do_tlb_invalidate_nested_tlb(vcpu, lpid, pg_sizes,
1353 						    start, end);
1354 	return H_SUCCESS;
1355 }
1356 
1357 /* Used to convert a nested guest real address to a L1 guest real address */
1358 static int kvmhv_translate_addr_nested(struct kvm_vcpu *vcpu,
1359 				       struct kvm_nested_guest *gp,
1360 				       unsigned long n_gpa, unsigned long dsisr,
1361 				       struct kvmppc_pte *gpte_p)
1362 {
1363 	u64 fault_addr, flags = dsisr & DSISR_ISSTORE;
1364 	int ret;
1365 
1366 	ret = kvmppc_mmu_walk_radix_tree(vcpu, n_gpa, gpte_p, gp->l1_gr_to_hr,
1367 					 &fault_addr);
1368 
1369 	if (ret) {
1370 		/* We didn't find a pte */
1371 		if (ret == -EINVAL) {
1372 			/* Unsupported mmu config */
1373 			flags |= DSISR_UNSUPP_MMU;
1374 		} else if (ret == -ENOENT) {
1375 			/* No translation found */
1376 			flags |= DSISR_NOHPTE;
1377 		} else if (ret == -EFAULT) {
1378 			/* Couldn't access L1 real address */
1379 			flags |= DSISR_PRTABLE_FAULT;
1380 			vcpu->arch.fault_gpa = fault_addr;
1381 		} else {
1382 			/* Unknown error */
1383 			return ret;
1384 		}
1385 		goto forward_to_l1;
1386 	} else {
1387 		/* We found a pte -> check permissions */
1388 		if (dsisr & DSISR_ISSTORE) {
1389 			/* Can we write? */
1390 			if (!gpte_p->may_write) {
1391 				flags |= DSISR_PROTFAULT;
1392 				goto forward_to_l1;
1393 			}
1394 		} else if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
1395 			/* Can we execute? */
1396 			if (!gpte_p->may_execute) {
1397 				flags |= SRR1_ISI_N_G_OR_CIP;
1398 				goto forward_to_l1;
1399 			}
1400 		} else {
1401 			/* Can we read? */
1402 			if (!gpte_p->may_read && !gpte_p->may_write) {
1403 				flags |= DSISR_PROTFAULT;
1404 				goto forward_to_l1;
1405 			}
1406 		}
1407 	}
1408 
1409 	return 0;
1410 
1411 forward_to_l1:
1412 	vcpu->arch.fault_dsisr = flags;
1413 	if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
1414 		vcpu->arch.shregs.msr &= SRR1_MSR_BITS;
1415 		vcpu->arch.shregs.msr |= flags;
1416 	}
1417 	return RESUME_HOST;
1418 }
1419 
1420 static long kvmhv_handle_nested_set_rc(struct kvm_vcpu *vcpu,
1421 				       struct kvm_nested_guest *gp,
1422 				       unsigned long n_gpa,
1423 				       struct kvmppc_pte gpte,
1424 				       unsigned long dsisr)
1425 {
1426 	struct kvm *kvm = vcpu->kvm;
1427 	bool writing = !!(dsisr & DSISR_ISSTORE);
1428 	u64 pgflags;
1429 	long ret;
1430 
1431 	/* Are the rc bits set in the L1 partition scoped pte? */
1432 	pgflags = _PAGE_ACCESSED;
1433 	if (writing)
1434 		pgflags |= _PAGE_DIRTY;
1435 	if (pgflags & ~gpte.rc)
1436 		return RESUME_HOST;
1437 
1438 	spin_lock(&kvm->mmu_lock);
1439 	/* Set the rc bit in the pte of our (L0) pgtable for the L1 guest */
1440 	ret = kvmppc_hv_handle_set_rc(kvm, false, writing,
1441 				      gpte.raddr, kvm->arch.lpid);
1442 	if (!ret) {
1443 		ret = -EINVAL;
1444 		goto out_unlock;
1445 	}
1446 
1447 	/* Set the rc bit in the pte of the shadow_pgtable for the nest guest */
1448 	ret = kvmppc_hv_handle_set_rc(kvm, true, writing,
1449 				      n_gpa, gp->l1_lpid);
1450 	if (!ret)
1451 		ret = -EINVAL;
1452 	else
1453 		ret = 0;
1454 
1455 out_unlock:
1456 	spin_unlock(&kvm->mmu_lock);
1457 	return ret;
1458 }
1459 
1460 static inline int kvmppc_radix_level_to_shift(int level)
1461 {
1462 	switch (level) {
1463 	case 2:
1464 		return PUD_SHIFT;
1465 	case 1:
1466 		return PMD_SHIFT;
1467 	default:
1468 		return PAGE_SHIFT;
1469 	}
1470 }
1471 
1472 static inline int kvmppc_radix_shift_to_level(int shift)
1473 {
1474 	if (shift == PUD_SHIFT)
1475 		return 2;
1476 	if (shift == PMD_SHIFT)
1477 		return 1;
1478 	if (shift == PAGE_SHIFT)
1479 		return 0;
1480 	WARN_ON_ONCE(1);
1481 	return 0;
1482 }
1483 
1484 /* called with gp->tlb_lock held */
1485 static long int __kvmhv_nested_page_fault(struct kvm_vcpu *vcpu,
1486 					  struct kvm_nested_guest *gp)
1487 {
1488 	struct kvm *kvm = vcpu->kvm;
1489 	struct kvm_memory_slot *memslot;
1490 	struct rmap_nested *n_rmap;
1491 	struct kvmppc_pte gpte;
1492 	pte_t pte, *pte_p;
1493 	unsigned long mmu_seq;
1494 	unsigned long dsisr = vcpu->arch.fault_dsisr;
1495 	unsigned long ea = vcpu->arch.fault_dar;
1496 	unsigned long *rmapp;
1497 	unsigned long n_gpa, gpa, gfn, perm = 0UL;
1498 	unsigned int shift, l1_shift, level;
1499 	bool writing = !!(dsisr & DSISR_ISSTORE);
1500 	bool kvm_ro = false;
1501 	long int ret;
1502 
1503 	if (!gp->l1_gr_to_hr) {
1504 		kvmhv_update_ptbl_cache(gp);
1505 		if (!gp->l1_gr_to_hr)
1506 			return RESUME_HOST;
1507 	}
1508 
1509 	/* Convert the nested guest real address into a L1 guest real address */
1510 
1511 	n_gpa = vcpu->arch.fault_gpa & ~0xF000000000000FFFULL;
1512 	if (!(dsisr & DSISR_PRTABLE_FAULT))
1513 		n_gpa |= ea & 0xFFF;
1514 	ret = kvmhv_translate_addr_nested(vcpu, gp, n_gpa, dsisr, &gpte);
1515 
1516 	/*
1517 	 * If the hardware found a translation but we don't now have a usable
1518 	 * translation in the l1 partition-scoped tree, remove the shadow pte
1519 	 * and let the guest retry.
1520 	 */
1521 	if (ret == RESUME_HOST &&
1522 	    (dsisr & (DSISR_PROTFAULT | DSISR_BADACCESS | DSISR_NOEXEC_OR_G |
1523 		      DSISR_BAD_COPYPASTE)))
1524 		goto inval;
1525 	if (ret)
1526 		return ret;
1527 
1528 	/* Failed to set the reference/change bits */
1529 	if (dsisr & DSISR_SET_RC) {
1530 		ret = kvmhv_handle_nested_set_rc(vcpu, gp, n_gpa, gpte, dsisr);
1531 		if (ret == RESUME_HOST)
1532 			return ret;
1533 		if (ret)
1534 			goto inval;
1535 		dsisr &= ~DSISR_SET_RC;
1536 		if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
1537 			       DSISR_PROTFAULT)))
1538 			return RESUME_GUEST;
1539 	}
1540 
1541 	/*
1542 	 * We took an HISI or HDSI while we were running a nested guest which
1543 	 * means we have no partition scoped translation for that. This means
1544 	 * we need to insert a pte for the mapping into our shadow_pgtable.
1545 	 */
1546 
1547 	l1_shift = gpte.page_shift;
1548 	if (l1_shift < PAGE_SHIFT) {
1549 		/* We don't support l1 using a page size smaller than our own */
1550 		pr_err("KVM: L1 guest page shift (%d) less than our own (%d)\n",
1551 			l1_shift, PAGE_SHIFT);
1552 		return -EINVAL;
1553 	}
1554 	gpa = gpte.raddr;
1555 	gfn = gpa >> PAGE_SHIFT;
1556 
1557 	/* 1. Get the corresponding host memslot */
1558 
1559 	memslot = gfn_to_memslot(kvm, gfn);
1560 	if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
1561 		if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS)) {
1562 			/* unusual error -> reflect to the guest as a DSI */
1563 			kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
1564 			return RESUME_GUEST;
1565 		}
1566 
1567 		/* passthrough of emulated MMIO case */
1568 		return kvmppc_hv_emulate_mmio(vcpu, gpa, ea, writing);
1569 	}
1570 	if (memslot->flags & KVM_MEM_READONLY) {
1571 		if (writing) {
1572 			/* Give the guest a DSI */
1573 			kvmppc_core_queue_data_storage(vcpu, ea,
1574 					DSISR_ISSTORE | DSISR_PROTFAULT);
1575 			return RESUME_GUEST;
1576 		}
1577 		kvm_ro = true;
1578 	}
1579 
1580 	/* 2. Find the host pte for this L1 guest real address */
1581 
1582 	/* Used to check for invalidations in progress */
1583 	mmu_seq = kvm->mmu_notifier_seq;
1584 	smp_rmb();
1585 
1586 	/* See if can find translation in our partition scoped tables for L1 */
1587 	pte = __pte(0);
1588 	spin_lock(&kvm->mmu_lock);
1589 	pte_p = find_kvm_secondary_pte(kvm, gpa, &shift);
1590 	if (!shift)
1591 		shift = PAGE_SHIFT;
1592 	if (pte_p)
1593 		pte = *pte_p;
1594 	spin_unlock(&kvm->mmu_lock);
1595 
1596 	if (!pte_present(pte) || (writing && !(pte_val(pte) & _PAGE_WRITE))) {
1597 		/* No suitable pte found -> try to insert a mapping */
1598 		ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot,
1599 					writing, kvm_ro, &pte, &level);
1600 		if (ret == -EAGAIN)
1601 			return RESUME_GUEST;
1602 		else if (ret)
1603 			return ret;
1604 		shift = kvmppc_radix_level_to_shift(level);
1605 	}
1606 	/* Align gfn to the start of the page */
1607 	gfn = (gpa & ~((1UL << shift) - 1)) >> PAGE_SHIFT;
1608 
1609 	/* 3. Compute the pte we need to insert for nest_gpa -> host r_addr */
1610 
1611 	/* The permissions is the combination of the host and l1 guest ptes */
1612 	perm |= gpte.may_read ? 0UL : _PAGE_READ;
1613 	perm |= gpte.may_write ? 0UL : _PAGE_WRITE;
1614 	perm |= gpte.may_execute ? 0UL : _PAGE_EXEC;
1615 	/* Only set accessed/dirty (rc) bits if set in host and l1 guest ptes */
1616 	perm |= (gpte.rc & _PAGE_ACCESSED) ? 0UL : _PAGE_ACCESSED;
1617 	perm |= ((gpte.rc & _PAGE_DIRTY) && writing) ? 0UL : _PAGE_DIRTY;
1618 	pte = __pte(pte_val(pte) & ~perm);
1619 
1620 	/* What size pte can we insert? */
1621 	if (shift > l1_shift) {
1622 		u64 mask;
1623 		unsigned int actual_shift = PAGE_SHIFT;
1624 		if (PMD_SHIFT < l1_shift)
1625 			actual_shift = PMD_SHIFT;
1626 		mask = (1UL << shift) - (1UL << actual_shift);
1627 		pte = __pte(pte_val(pte) | (gpa & mask));
1628 		shift = actual_shift;
1629 	}
1630 	level = kvmppc_radix_shift_to_level(shift);
1631 	n_gpa &= ~((1UL << shift) - 1);
1632 
1633 	/* 4. Insert the pte into our shadow_pgtable */
1634 
1635 	n_rmap = kzalloc(sizeof(*n_rmap), GFP_KERNEL);
1636 	if (!n_rmap)
1637 		return RESUME_GUEST; /* Let the guest try again */
1638 	n_rmap->rmap = (n_gpa & RMAP_NESTED_GPA_MASK) |
1639 		(((unsigned long) gp->l1_lpid) << RMAP_NESTED_LPID_SHIFT);
1640 	rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1641 	ret = kvmppc_create_pte(kvm, gp->shadow_pgtable, pte, n_gpa, level,
1642 				mmu_seq, gp->shadow_lpid, rmapp, &n_rmap);
1643 	kfree(n_rmap);
1644 	if (ret == -EAGAIN)
1645 		ret = RESUME_GUEST;	/* Let the guest try again */
1646 
1647 	return ret;
1648 
1649  inval:
1650 	kvmhv_invalidate_shadow_pte(vcpu, gp, n_gpa, NULL);
1651 	return RESUME_GUEST;
1652 }
1653 
1654 long int kvmhv_nested_page_fault(struct kvm_vcpu *vcpu)
1655 {
1656 	struct kvm_nested_guest *gp = vcpu->arch.nested;
1657 	long int ret;
1658 
1659 	mutex_lock(&gp->tlb_lock);
1660 	ret = __kvmhv_nested_page_fault(vcpu, gp);
1661 	mutex_unlock(&gp->tlb_lock);
1662 	return ret;
1663 }
1664 
1665 int kvmhv_nested_next_lpid(struct kvm *kvm, int lpid)
1666 {
1667 	int ret = lpid + 1;
1668 
1669 	spin_lock(&kvm->mmu_lock);
1670 	if (!idr_get_next(&kvm->arch.kvm_nested_guest_idr, &ret))
1671 		ret = -1;
1672 	spin_unlock(&kvm->mmu_lock);
1673 
1674 	return ret;
1675 }
1676