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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 
24 static struct patb_entry *pseries_partition_tb;
25 
26 static void kvmhv_update_ptbl_cache(struct kvm_nested_guest *gp);
27 static void kvmhv_free_memslot_nest_rmap(struct kvm_memory_slot *free);
28 
kvmhv_save_hv_regs(struct kvm_vcpu * vcpu,struct hv_guest_state * hr)29 void kvmhv_save_hv_regs(struct kvm_vcpu *vcpu, struct hv_guest_state *hr)
30 {
31 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
32 
33 	hr->pcr = vc->pcr | PCR_MASK;
34 	hr->dpdes = vc->dpdes;
35 	hr->hfscr = vcpu->arch.hfscr;
36 	hr->tb_offset = vc->tb_offset;
37 	hr->dawr0 = vcpu->arch.dawr0;
38 	hr->dawrx0 = vcpu->arch.dawrx0;
39 	hr->ciabr = vcpu->arch.ciabr;
40 	hr->purr = vcpu->arch.purr;
41 	hr->spurr = vcpu->arch.spurr;
42 	hr->ic = vcpu->arch.ic;
43 	hr->vtb = vc->vtb;
44 	hr->srr0 = vcpu->arch.shregs.srr0;
45 	hr->srr1 = vcpu->arch.shregs.srr1;
46 	hr->sprg[0] = vcpu->arch.shregs.sprg0;
47 	hr->sprg[1] = vcpu->arch.shregs.sprg1;
48 	hr->sprg[2] = vcpu->arch.shregs.sprg2;
49 	hr->sprg[3] = vcpu->arch.shregs.sprg3;
50 	hr->pidr = vcpu->arch.pid;
51 	hr->cfar = vcpu->arch.cfar;
52 	hr->ppr = vcpu->arch.ppr;
53 	hr->dawr1 = vcpu->arch.dawr1;
54 	hr->dawrx1 = vcpu->arch.dawrx1;
55 }
56 
57 /* Use noinline_for_stack due to https://bugs.llvm.org/show_bug.cgi?id=49610 */
byteswap_pt_regs(struct pt_regs * regs)58 static noinline_for_stack void byteswap_pt_regs(struct pt_regs *regs)
59 {
60 	unsigned long *addr = (unsigned long *) regs;
61 
62 	for (; addr < ((unsigned long *) (regs + 1)); addr++)
63 		*addr = swab64(*addr);
64 }
65 
byteswap_hv_regs(struct hv_guest_state * hr)66 static void byteswap_hv_regs(struct hv_guest_state *hr)
67 {
68 	hr->version = swab64(hr->version);
69 	hr->lpid = swab32(hr->lpid);
70 	hr->vcpu_token = swab32(hr->vcpu_token);
71 	hr->lpcr = swab64(hr->lpcr);
72 	hr->pcr = swab64(hr->pcr) | PCR_MASK;
73 	hr->amor = swab64(hr->amor);
74 	hr->dpdes = swab64(hr->dpdes);
75 	hr->hfscr = swab64(hr->hfscr);
76 	hr->tb_offset = swab64(hr->tb_offset);
77 	hr->dawr0 = swab64(hr->dawr0);
78 	hr->dawrx0 = swab64(hr->dawrx0);
79 	hr->ciabr = swab64(hr->ciabr);
80 	hr->hdec_expiry = swab64(hr->hdec_expiry);
81 	hr->purr = swab64(hr->purr);
82 	hr->spurr = swab64(hr->spurr);
83 	hr->ic = swab64(hr->ic);
84 	hr->vtb = swab64(hr->vtb);
85 	hr->hdar = swab64(hr->hdar);
86 	hr->hdsisr = swab64(hr->hdsisr);
87 	hr->heir = swab64(hr->heir);
88 	hr->asdr = swab64(hr->asdr);
89 	hr->srr0 = swab64(hr->srr0);
90 	hr->srr1 = swab64(hr->srr1);
91 	hr->sprg[0] = swab64(hr->sprg[0]);
92 	hr->sprg[1] = swab64(hr->sprg[1]);
93 	hr->sprg[2] = swab64(hr->sprg[2]);
94 	hr->sprg[3] = swab64(hr->sprg[3]);
95 	hr->pidr = swab64(hr->pidr);
96 	hr->cfar = swab64(hr->cfar);
97 	hr->ppr = swab64(hr->ppr);
98 	hr->dawr1 = swab64(hr->dawr1);
99 	hr->dawrx1 = swab64(hr->dawrx1);
100 }
101 
save_hv_return_state(struct kvm_vcpu * vcpu,struct hv_guest_state * hr)102 static void save_hv_return_state(struct kvm_vcpu *vcpu,
103 				 struct hv_guest_state *hr)
104 {
105 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
106 
107 	hr->dpdes = vc->dpdes;
108 	hr->purr = vcpu->arch.purr;
109 	hr->spurr = vcpu->arch.spurr;
110 	hr->ic = vcpu->arch.ic;
111 	hr->vtb = vc->vtb;
112 	hr->srr0 = vcpu->arch.shregs.srr0;
113 	hr->srr1 = vcpu->arch.shregs.srr1;
114 	hr->sprg[0] = vcpu->arch.shregs.sprg0;
115 	hr->sprg[1] = vcpu->arch.shregs.sprg1;
116 	hr->sprg[2] = vcpu->arch.shregs.sprg2;
117 	hr->sprg[3] = vcpu->arch.shregs.sprg3;
118 	hr->pidr = vcpu->arch.pid;
119 	hr->cfar = vcpu->arch.cfar;
120 	hr->ppr = vcpu->arch.ppr;
121 	switch (vcpu->arch.trap) {
122 	case BOOK3S_INTERRUPT_H_DATA_STORAGE:
123 		hr->hdar = vcpu->arch.fault_dar;
124 		hr->hdsisr = vcpu->arch.fault_dsisr;
125 		hr->asdr = vcpu->arch.fault_gpa;
126 		break;
127 	case BOOK3S_INTERRUPT_H_INST_STORAGE:
128 		hr->asdr = vcpu->arch.fault_gpa;
129 		break;
130 	case BOOK3S_INTERRUPT_H_FAC_UNAVAIL:
131 		hr->hfscr = ((~HFSCR_INTR_CAUSE & hr->hfscr) |
132 			     (HFSCR_INTR_CAUSE & vcpu->arch.hfscr));
133 		break;
134 	case BOOK3S_INTERRUPT_H_EMUL_ASSIST:
135 		hr->heir = vcpu->arch.emul_inst;
136 		break;
137 	}
138 }
139 
restore_hv_regs(struct kvm_vcpu * vcpu,const struct hv_guest_state * hr)140 static void restore_hv_regs(struct kvm_vcpu *vcpu, const struct hv_guest_state *hr)
141 {
142 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
143 
144 	vc->pcr = hr->pcr | PCR_MASK;
145 	vc->dpdes = hr->dpdes;
146 	vcpu->arch.hfscr = hr->hfscr;
147 	vcpu->arch.dawr0 = hr->dawr0;
148 	vcpu->arch.dawrx0 = hr->dawrx0;
149 	vcpu->arch.ciabr = hr->ciabr;
150 	vcpu->arch.purr = hr->purr;
151 	vcpu->arch.spurr = hr->spurr;
152 	vcpu->arch.ic = hr->ic;
153 	vc->vtb = hr->vtb;
154 	vcpu->arch.shregs.srr0 = hr->srr0;
155 	vcpu->arch.shregs.srr1 = hr->srr1;
156 	vcpu->arch.shregs.sprg0 = hr->sprg[0];
157 	vcpu->arch.shregs.sprg1 = hr->sprg[1];
158 	vcpu->arch.shregs.sprg2 = hr->sprg[2];
159 	vcpu->arch.shregs.sprg3 = hr->sprg[3];
160 	vcpu->arch.pid = hr->pidr;
161 	vcpu->arch.cfar = hr->cfar;
162 	vcpu->arch.ppr = hr->ppr;
163 	vcpu->arch.dawr1 = hr->dawr1;
164 	vcpu->arch.dawrx1 = hr->dawrx1;
165 }
166 
kvmhv_restore_hv_return_state(struct kvm_vcpu * vcpu,struct hv_guest_state * hr)167 void kvmhv_restore_hv_return_state(struct kvm_vcpu *vcpu,
168 				   struct hv_guest_state *hr)
169 {
170 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
171 
172 	vc->dpdes = hr->dpdes;
173 	vcpu->arch.hfscr = hr->hfscr;
174 	vcpu->arch.purr = hr->purr;
175 	vcpu->arch.spurr = hr->spurr;
176 	vcpu->arch.ic = hr->ic;
177 	vc->vtb = hr->vtb;
178 	vcpu->arch.fault_dar = hr->hdar;
179 	vcpu->arch.fault_dsisr = hr->hdsisr;
180 	vcpu->arch.fault_gpa = hr->asdr;
181 	vcpu->arch.emul_inst = hr->heir;
182 	vcpu->arch.shregs.srr0 = hr->srr0;
183 	vcpu->arch.shregs.srr1 = hr->srr1;
184 	vcpu->arch.shregs.sprg0 = hr->sprg[0];
185 	vcpu->arch.shregs.sprg1 = hr->sprg[1];
186 	vcpu->arch.shregs.sprg2 = hr->sprg[2];
187 	vcpu->arch.shregs.sprg3 = hr->sprg[3];
188 	vcpu->arch.pid = hr->pidr;
189 	vcpu->arch.cfar = hr->cfar;
190 	vcpu->arch.ppr = hr->ppr;
191 }
192 
kvmhv_nested_mmio_needed(struct kvm_vcpu * vcpu,u64 regs_ptr)193 static void kvmhv_nested_mmio_needed(struct kvm_vcpu *vcpu, u64 regs_ptr)
194 {
195 	/* No need to reflect the page fault to L1, we've handled it */
196 	vcpu->arch.trap = 0;
197 
198 	/*
199 	 * Since the L2 gprs have already been written back into L1 memory when
200 	 * we complete the mmio, store the L1 memory location of the L2 gpr
201 	 * being loaded into by the mmio so that the loaded value can be
202 	 * written there in kvmppc_complete_mmio_load()
203 	 */
204 	if (((vcpu->arch.io_gpr & KVM_MMIO_REG_EXT_MASK) == KVM_MMIO_REG_GPR)
205 	    && (vcpu->mmio_is_write == 0)) {
206 		vcpu->arch.nested_io_gpr = (gpa_t) regs_ptr +
207 					   offsetof(struct pt_regs,
208 						    gpr[vcpu->arch.io_gpr]);
209 		vcpu->arch.io_gpr = KVM_MMIO_REG_NESTED_GPR;
210 	}
211 }
212 
kvmhv_read_guest_state_and_regs(struct kvm_vcpu * vcpu,struct hv_guest_state * l2_hv,struct pt_regs * l2_regs,u64 hv_ptr,u64 regs_ptr)213 static int kvmhv_read_guest_state_and_regs(struct kvm_vcpu *vcpu,
214 					   struct hv_guest_state *l2_hv,
215 					   struct pt_regs *l2_regs,
216 					   u64 hv_ptr, u64 regs_ptr)
217 {
218 	int size;
219 
220 	if (kvm_vcpu_read_guest(vcpu, hv_ptr, &l2_hv->version,
221 				sizeof(l2_hv->version)))
222 		return -1;
223 
224 	if (kvmppc_need_byteswap(vcpu))
225 		l2_hv->version = swab64(l2_hv->version);
226 
227 	size = hv_guest_state_size(l2_hv->version);
228 	if (size < 0)
229 		return -1;
230 
231 	return kvm_vcpu_read_guest(vcpu, hv_ptr, l2_hv, size) ||
232 		kvm_vcpu_read_guest(vcpu, regs_ptr, l2_regs,
233 				    sizeof(struct pt_regs));
234 }
235 
kvmhv_write_guest_state_and_regs(struct kvm_vcpu * vcpu,struct hv_guest_state * l2_hv,struct pt_regs * l2_regs,u64 hv_ptr,u64 regs_ptr)236 static int kvmhv_write_guest_state_and_regs(struct kvm_vcpu *vcpu,
237 					    struct hv_guest_state *l2_hv,
238 					    struct pt_regs *l2_regs,
239 					    u64 hv_ptr, u64 regs_ptr)
240 {
241 	int size;
242 
243 	size = hv_guest_state_size(l2_hv->version);
244 	if (size < 0)
245 		return -1;
246 
247 	return kvm_vcpu_write_guest(vcpu, hv_ptr, l2_hv, size) ||
248 		kvm_vcpu_write_guest(vcpu, regs_ptr, l2_regs,
249 				     sizeof(struct pt_regs));
250 }
251 
load_l2_hv_regs(struct kvm_vcpu * vcpu,const struct hv_guest_state * l2_hv,const struct hv_guest_state * l1_hv,u64 * lpcr)252 static void load_l2_hv_regs(struct kvm_vcpu *vcpu,
253 			    const struct hv_guest_state *l2_hv,
254 			    const struct hv_guest_state *l1_hv, u64 *lpcr)
255 {
256 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
257 	u64 mask;
258 
259 	restore_hv_regs(vcpu, l2_hv);
260 
261 	/*
262 	 * Don't let L1 change LPCR bits for the L2 except these:
263 	 */
264 	mask = LPCR_DPFD | LPCR_ILE | LPCR_TC | LPCR_AIL | LPCR_LD | LPCR_MER;
265 
266 	/*
267 	 * Additional filtering is required depending on hardware
268 	 * and configuration.
269 	 */
270 	*lpcr = kvmppc_filter_lpcr_hv(vcpu->kvm,
271 				      (vc->lpcr & ~mask) | (*lpcr & mask));
272 
273 	/*
274 	 * Don't let L1 enable features for L2 which we don't allow for L1,
275 	 * but preserve the interrupt cause field.
276 	 */
277 	vcpu->arch.hfscr = l2_hv->hfscr & (HFSCR_INTR_CAUSE | vcpu->arch.hfscr_permitted);
278 
279 	/* Don't let data address watchpoint match in hypervisor state */
280 	vcpu->arch.dawrx0 = l2_hv->dawrx0 & ~DAWRX_HYP;
281 	vcpu->arch.dawrx1 = l2_hv->dawrx1 & ~DAWRX_HYP;
282 
283 	/* Don't let completed instruction address breakpt match in HV state */
284 	if ((l2_hv->ciabr & CIABR_PRIV) == CIABR_PRIV_HYPER)
285 		vcpu->arch.ciabr = l2_hv->ciabr & ~CIABR_PRIV;
286 }
287 
kvmhv_enter_nested_guest(struct kvm_vcpu * vcpu)288 long kvmhv_enter_nested_guest(struct kvm_vcpu *vcpu)
289 {
290 	long int err, r;
291 	struct kvm_nested_guest *l2;
292 	struct pt_regs l2_regs, saved_l1_regs;
293 	struct hv_guest_state l2_hv = {0}, saved_l1_hv;
294 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
295 	u64 hv_ptr, regs_ptr;
296 	u64 hdec_exp, lpcr;
297 	s64 delta_purr, delta_spurr, delta_ic, delta_vtb;
298 
299 	if (vcpu->kvm->arch.l1_ptcr == 0)
300 		return H_NOT_AVAILABLE;
301 
302 	if (MSR_TM_TRANSACTIONAL(vcpu->arch.shregs.msr))
303 		return H_BAD_MODE;
304 
305 	/* copy parameters in */
306 	hv_ptr = kvmppc_get_gpr(vcpu, 4);
307 	regs_ptr = kvmppc_get_gpr(vcpu, 5);
308 	vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
309 	err = kvmhv_read_guest_state_and_regs(vcpu, &l2_hv, &l2_regs,
310 					      hv_ptr, regs_ptr);
311 	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
312 	if (err)
313 		return H_PARAMETER;
314 
315 	if (kvmppc_need_byteswap(vcpu))
316 		byteswap_hv_regs(&l2_hv);
317 	if (l2_hv.version > HV_GUEST_STATE_VERSION)
318 		return H_P2;
319 
320 	if (kvmppc_need_byteswap(vcpu))
321 		byteswap_pt_regs(&l2_regs);
322 	if (l2_hv.vcpu_token >= NR_CPUS)
323 		return H_PARAMETER;
324 
325 	/*
326 	 * L1 must have set up a suspended state to enter the L2 in a
327 	 * transactional state, and only in that case. These have to be
328 	 * filtered out here to prevent causing a TM Bad Thing in the
329 	 * host HRFID. We could synthesize a TM Bad Thing back to the L1
330 	 * here but there doesn't seem like much point.
331 	 */
332 	if (MSR_TM_SUSPENDED(vcpu->arch.shregs.msr)) {
333 		if (!MSR_TM_ACTIVE(l2_regs.msr))
334 			return H_BAD_MODE;
335 	} else {
336 		if (l2_regs.msr & MSR_TS_MASK)
337 			return H_BAD_MODE;
338 		if (WARN_ON_ONCE(vcpu->arch.shregs.msr & MSR_TS_MASK))
339 			return H_BAD_MODE;
340 	}
341 
342 	/* translate lpid */
343 	l2 = kvmhv_get_nested(vcpu->kvm, l2_hv.lpid, true);
344 	if (!l2)
345 		return H_PARAMETER;
346 	if (!l2->l1_gr_to_hr) {
347 		mutex_lock(&l2->tlb_lock);
348 		kvmhv_update_ptbl_cache(l2);
349 		mutex_unlock(&l2->tlb_lock);
350 	}
351 
352 	/* save l1 values of things */
353 	vcpu->arch.regs.msr = vcpu->arch.shregs.msr;
354 	saved_l1_regs = vcpu->arch.regs;
355 	kvmhv_save_hv_regs(vcpu, &saved_l1_hv);
356 
357 	/* convert TB values/offsets to host (L0) values */
358 	hdec_exp = l2_hv.hdec_expiry - vc->tb_offset;
359 	vc->tb_offset += l2_hv.tb_offset;
360 
361 	/* set L1 state to L2 state */
362 	vcpu->arch.nested = l2;
363 	vcpu->arch.nested_vcpu_id = l2_hv.vcpu_token;
364 	vcpu->arch.nested_hfscr = l2_hv.hfscr;
365 	vcpu->arch.regs = l2_regs;
366 
367 	/* Guest must always run with ME enabled, HV disabled. */
368 	vcpu->arch.shregs.msr = (vcpu->arch.regs.msr | MSR_ME) & ~MSR_HV;
369 
370 	lpcr = l2_hv.lpcr;
371 	load_l2_hv_regs(vcpu, &l2_hv, &saved_l1_hv, &lpcr);
372 
373 	vcpu->arch.ret = RESUME_GUEST;
374 	vcpu->arch.trap = 0;
375 	do {
376 		if (mftb() >= hdec_exp) {
377 			vcpu->arch.trap = BOOK3S_INTERRUPT_HV_DECREMENTER;
378 			r = RESUME_HOST;
379 			break;
380 		}
381 		r = kvmhv_run_single_vcpu(vcpu, hdec_exp, lpcr);
382 	} while (is_kvmppc_resume_guest(r));
383 
384 	/* save L2 state for return */
385 	l2_regs = vcpu->arch.regs;
386 	l2_regs.msr = vcpu->arch.shregs.msr;
387 	delta_purr = vcpu->arch.purr - l2_hv.purr;
388 	delta_spurr = vcpu->arch.spurr - l2_hv.spurr;
389 	delta_ic = vcpu->arch.ic - l2_hv.ic;
390 	delta_vtb = vc->vtb - l2_hv.vtb;
391 	save_hv_return_state(vcpu, &l2_hv);
392 
393 	/* restore L1 state */
394 	vcpu->arch.nested = NULL;
395 	vcpu->arch.regs = saved_l1_regs;
396 	vcpu->arch.shregs.msr = saved_l1_regs.msr & ~MSR_TS_MASK;
397 	/* set L1 MSR TS field according to L2 transaction state */
398 	if (l2_regs.msr & MSR_TS_MASK)
399 		vcpu->arch.shregs.msr |= MSR_TS_S;
400 	vc->tb_offset = saved_l1_hv.tb_offset;
401 	restore_hv_regs(vcpu, &saved_l1_hv);
402 	vcpu->arch.purr += delta_purr;
403 	vcpu->arch.spurr += delta_spurr;
404 	vcpu->arch.ic += delta_ic;
405 	vc->vtb += delta_vtb;
406 
407 	kvmhv_put_nested(l2);
408 
409 	/* copy l2_hv_state and regs back to guest */
410 	if (kvmppc_need_byteswap(vcpu)) {
411 		byteswap_hv_regs(&l2_hv);
412 		byteswap_pt_regs(&l2_regs);
413 	}
414 	vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
415 	err = kvmhv_write_guest_state_and_regs(vcpu, &l2_hv, &l2_regs,
416 					       hv_ptr, regs_ptr);
417 	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
418 	if (err)
419 		return H_AUTHORITY;
420 
421 	if (r == -EINTR)
422 		return H_INTERRUPT;
423 
424 	if (vcpu->mmio_needed) {
425 		kvmhv_nested_mmio_needed(vcpu, regs_ptr);
426 		return H_TOO_HARD;
427 	}
428 
429 	return vcpu->arch.trap;
430 }
431 
kvmhv_nested_init(void)432 long kvmhv_nested_init(void)
433 {
434 	long int ptb_order;
435 	unsigned long ptcr;
436 	long rc;
437 
438 	if (!kvmhv_on_pseries())
439 		return 0;
440 	if (!radix_enabled())
441 		return -ENODEV;
442 
443 	/* find log base 2 of KVMPPC_NR_LPIDS, rounding up */
444 	ptb_order = __ilog2(KVMPPC_NR_LPIDS - 1) + 1;
445 	if (ptb_order < 8)
446 		ptb_order = 8;
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 - 8);
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 
kvmhv_nested_exit(void)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 
kvmhv_flush_lpid(unsigned int lpid)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 
kvmhv_set_ptbl_entry(unsigned int lpid,u64 dw0,u64 dw1)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 
kvmhv_set_nested_ptbl(struct kvm_nested_guest * gp)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 
kvmhv_vm_nested_init(struct kvm * kvm)525 void kvmhv_vm_nested_init(struct kvm *kvm)
526 {
527 	kvm->arch.max_nested_lpid = -1;
528 }
529 
530 /*
531  * Handle the H_SET_PARTITION_TABLE hcall.
532  * r4 = guest real address of partition table + log_2(size) - 12
533  * (formatted as for the PTCR).
534  */
kvmhv_set_partition_table(struct kvm_vcpu * vcpu)535 long kvmhv_set_partition_table(struct kvm_vcpu *vcpu)
536 {
537 	struct kvm *kvm = vcpu->kvm;
538 	unsigned long ptcr = kvmppc_get_gpr(vcpu, 4);
539 	int srcu_idx;
540 	long ret = H_SUCCESS;
541 
542 	srcu_idx = srcu_read_lock(&kvm->srcu);
543 	/*
544 	 * Limit the partition table to 4096 entries (because that's what
545 	 * hardware supports), and check the base address.
546 	 */
547 	if ((ptcr & PRTS_MASK) > 12 - 8 ||
548 	    !kvm_is_visible_gfn(vcpu->kvm, (ptcr & PRTB_MASK) >> PAGE_SHIFT))
549 		ret = H_PARAMETER;
550 	srcu_read_unlock(&kvm->srcu, srcu_idx);
551 	if (ret == H_SUCCESS)
552 		kvm->arch.l1_ptcr = ptcr;
553 	return ret;
554 }
555 
556 /*
557  * Handle the H_COPY_TOFROM_GUEST hcall.
558  * r4 = L1 lpid of nested guest
559  * r5 = pid
560  * r6 = eaddr to access
561  * r7 = to buffer (L1 gpa)
562  * r8 = from buffer (L1 gpa)
563  * r9 = n bytes to copy
564  */
kvmhv_copy_tofrom_guest_nested(struct kvm_vcpu * vcpu)565 long kvmhv_copy_tofrom_guest_nested(struct kvm_vcpu *vcpu)
566 {
567 	struct kvm_nested_guest *gp;
568 	int l1_lpid = kvmppc_get_gpr(vcpu, 4);
569 	int pid = kvmppc_get_gpr(vcpu, 5);
570 	gva_t eaddr = kvmppc_get_gpr(vcpu, 6);
571 	gpa_t gp_to = (gpa_t) kvmppc_get_gpr(vcpu, 7);
572 	gpa_t gp_from = (gpa_t) kvmppc_get_gpr(vcpu, 8);
573 	void *buf;
574 	unsigned long n = kvmppc_get_gpr(vcpu, 9);
575 	bool is_load = !!gp_to;
576 	long rc;
577 
578 	if (gp_to && gp_from) /* One must be NULL to determine the direction */
579 		return H_PARAMETER;
580 
581 	if (eaddr & (0xFFFUL << 52))
582 		return H_PARAMETER;
583 
584 	buf = kzalloc(n, GFP_KERNEL | __GFP_NOWARN);
585 	if (!buf)
586 		return H_NO_MEM;
587 
588 	gp = kvmhv_get_nested(vcpu->kvm, l1_lpid, false);
589 	if (!gp) {
590 		rc = H_PARAMETER;
591 		goto out_free;
592 	}
593 
594 	mutex_lock(&gp->tlb_lock);
595 
596 	if (is_load) {
597 		/* Load from the nested guest into our buffer */
598 		rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid,
599 						     eaddr, buf, NULL, n);
600 		if (rc)
601 			goto not_found;
602 
603 		/* Write what was loaded into our buffer back to the L1 guest */
604 		vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
605 		rc = kvm_vcpu_write_guest(vcpu, gp_to, buf, n);
606 		srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
607 		if (rc)
608 			goto not_found;
609 	} else {
610 		/* Load the data to be stored from the L1 guest into our buf */
611 		vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
612 		rc = kvm_vcpu_read_guest(vcpu, gp_from, buf, n);
613 		srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
614 		if (rc)
615 			goto not_found;
616 
617 		/* Store from our buffer into the nested guest */
618 		rc = __kvmhv_copy_tofrom_guest_radix(gp->shadow_lpid, pid,
619 						     eaddr, NULL, buf, n);
620 		if (rc)
621 			goto not_found;
622 	}
623 
624 out_unlock:
625 	mutex_unlock(&gp->tlb_lock);
626 	kvmhv_put_nested(gp);
627 out_free:
628 	kfree(buf);
629 	return rc;
630 not_found:
631 	rc = H_NOT_FOUND;
632 	goto out_unlock;
633 }
634 
635 /*
636  * Reload the partition table entry for a guest.
637  * Caller must hold gp->tlb_lock.
638  */
kvmhv_update_ptbl_cache(struct kvm_nested_guest * gp)639 static void kvmhv_update_ptbl_cache(struct kvm_nested_guest *gp)
640 {
641 	int ret;
642 	struct patb_entry ptbl_entry;
643 	unsigned long ptbl_addr;
644 	struct kvm *kvm = gp->l1_host;
645 
646 	ret = -EFAULT;
647 	ptbl_addr = (kvm->arch.l1_ptcr & PRTB_MASK) + (gp->l1_lpid << 4);
648 	if (gp->l1_lpid < (1ul << ((kvm->arch.l1_ptcr & PRTS_MASK) + 8))) {
649 		int srcu_idx = srcu_read_lock(&kvm->srcu);
650 		ret = kvm_read_guest(kvm, ptbl_addr,
651 				     &ptbl_entry, sizeof(ptbl_entry));
652 		srcu_read_unlock(&kvm->srcu, srcu_idx);
653 	}
654 	if (ret) {
655 		gp->l1_gr_to_hr = 0;
656 		gp->process_table = 0;
657 	} else {
658 		gp->l1_gr_to_hr = be64_to_cpu(ptbl_entry.patb0);
659 		gp->process_table = be64_to_cpu(ptbl_entry.patb1);
660 	}
661 	kvmhv_set_nested_ptbl(gp);
662 }
663 
kvmhv_alloc_nested(struct kvm * kvm,unsigned int lpid)664 static struct kvm_nested_guest *kvmhv_alloc_nested(struct kvm *kvm, unsigned int lpid)
665 {
666 	struct kvm_nested_guest *gp;
667 	long shadow_lpid;
668 
669 	gp = kzalloc(sizeof(*gp), GFP_KERNEL);
670 	if (!gp)
671 		return NULL;
672 	gp->l1_host = kvm;
673 	gp->l1_lpid = lpid;
674 	mutex_init(&gp->tlb_lock);
675 	gp->shadow_pgtable = pgd_alloc(kvm->mm);
676 	if (!gp->shadow_pgtable)
677 		goto out_free;
678 	shadow_lpid = kvmppc_alloc_lpid();
679 	if (shadow_lpid < 0)
680 		goto out_free2;
681 	gp->shadow_lpid = shadow_lpid;
682 	gp->radix = 1;
683 
684 	memset(gp->prev_cpu, -1, sizeof(gp->prev_cpu));
685 
686 	return gp;
687 
688  out_free2:
689 	pgd_free(kvm->mm, gp->shadow_pgtable);
690  out_free:
691 	kfree(gp);
692 	return NULL;
693 }
694 
695 /*
696  * Free up any resources allocated for a nested guest.
697  */
kvmhv_release_nested(struct kvm_nested_guest * gp)698 static void kvmhv_release_nested(struct kvm_nested_guest *gp)
699 {
700 	struct kvm *kvm = gp->l1_host;
701 
702 	if (gp->shadow_pgtable) {
703 		/*
704 		 * No vcpu is using this struct and no call to
705 		 * kvmhv_get_nested can find this struct,
706 		 * so we don't need to hold kvm->mmu_lock.
707 		 */
708 		kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable,
709 					  gp->shadow_lpid);
710 		pgd_free(kvm->mm, gp->shadow_pgtable);
711 	}
712 	kvmhv_set_ptbl_entry(gp->shadow_lpid, 0, 0);
713 	kvmppc_free_lpid(gp->shadow_lpid);
714 	kfree(gp);
715 }
716 
kvmhv_remove_nested(struct kvm_nested_guest * gp)717 static void kvmhv_remove_nested(struct kvm_nested_guest *gp)
718 {
719 	struct kvm *kvm = gp->l1_host;
720 	int lpid = gp->l1_lpid;
721 	long ref;
722 
723 	spin_lock(&kvm->mmu_lock);
724 	if (gp == kvm->arch.nested_guests[lpid]) {
725 		kvm->arch.nested_guests[lpid] = NULL;
726 		if (lpid == kvm->arch.max_nested_lpid) {
727 			while (--lpid >= 0 && !kvm->arch.nested_guests[lpid])
728 				;
729 			kvm->arch.max_nested_lpid = lpid;
730 		}
731 		--gp->refcnt;
732 	}
733 	ref = gp->refcnt;
734 	spin_unlock(&kvm->mmu_lock);
735 	if (ref == 0)
736 		kvmhv_release_nested(gp);
737 }
738 
739 /*
740  * Free up all nested resources allocated for this guest.
741  * This is called with no vcpus of the guest running, when
742  * switching the guest to HPT mode or when destroying the
743  * guest.
744  */
kvmhv_release_all_nested(struct kvm * kvm)745 void kvmhv_release_all_nested(struct kvm *kvm)
746 {
747 	int i;
748 	struct kvm_nested_guest *gp;
749 	struct kvm_nested_guest *freelist = NULL;
750 	struct kvm_memory_slot *memslot;
751 	int srcu_idx;
752 
753 	spin_lock(&kvm->mmu_lock);
754 	for (i = 0; i <= kvm->arch.max_nested_lpid; i++) {
755 		gp = kvm->arch.nested_guests[i];
756 		if (!gp)
757 			continue;
758 		kvm->arch.nested_guests[i] = NULL;
759 		if (--gp->refcnt == 0) {
760 			gp->next = freelist;
761 			freelist = gp;
762 		}
763 	}
764 	kvm->arch.max_nested_lpid = -1;
765 	spin_unlock(&kvm->mmu_lock);
766 	while ((gp = freelist) != NULL) {
767 		freelist = gp->next;
768 		kvmhv_release_nested(gp);
769 	}
770 
771 	srcu_idx = srcu_read_lock(&kvm->srcu);
772 	kvm_for_each_memslot(memslot, kvm_memslots(kvm))
773 		kvmhv_free_memslot_nest_rmap(memslot);
774 	srcu_read_unlock(&kvm->srcu, srcu_idx);
775 }
776 
777 /* caller must hold gp->tlb_lock */
kvmhv_flush_nested(struct kvm_nested_guest * gp)778 static void kvmhv_flush_nested(struct kvm_nested_guest *gp)
779 {
780 	struct kvm *kvm = gp->l1_host;
781 
782 	spin_lock(&kvm->mmu_lock);
783 	kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable, gp->shadow_lpid);
784 	spin_unlock(&kvm->mmu_lock);
785 	kvmhv_flush_lpid(gp->shadow_lpid);
786 	kvmhv_update_ptbl_cache(gp);
787 	if (gp->l1_gr_to_hr == 0)
788 		kvmhv_remove_nested(gp);
789 }
790 
kvmhv_get_nested(struct kvm * kvm,int l1_lpid,bool create)791 struct kvm_nested_guest *kvmhv_get_nested(struct kvm *kvm, int l1_lpid,
792 					  bool create)
793 {
794 	struct kvm_nested_guest *gp, *newgp;
795 
796 	if (l1_lpid >= KVM_MAX_NESTED_GUESTS ||
797 	    l1_lpid >= (1ul << ((kvm->arch.l1_ptcr & PRTS_MASK) + 12 - 4)))
798 		return NULL;
799 
800 	spin_lock(&kvm->mmu_lock);
801 	gp = kvm->arch.nested_guests[l1_lpid];
802 	if (gp)
803 		++gp->refcnt;
804 	spin_unlock(&kvm->mmu_lock);
805 
806 	if (gp || !create)
807 		return gp;
808 
809 	newgp = kvmhv_alloc_nested(kvm, l1_lpid);
810 	if (!newgp)
811 		return NULL;
812 	spin_lock(&kvm->mmu_lock);
813 	if (kvm->arch.nested_guests[l1_lpid]) {
814 		/* someone else beat us to it */
815 		gp = kvm->arch.nested_guests[l1_lpid];
816 	} else {
817 		kvm->arch.nested_guests[l1_lpid] = newgp;
818 		++newgp->refcnt;
819 		gp = newgp;
820 		newgp = NULL;
821 		if (l1_lpid > kvm->arch.max_nested_lpid)
822 			kvm->arch.max_nested_lpid = l1_lpid;
823 	}
824 	++gp->refcnt;
825 	spin_unlock(&kvm->mmu_lock);
826 
827 	if (newgp)
828 		kvmhv_release_nested(newgp);
829 
830 	return gp;
831 }
832 
kvmhv_put_nested(struct kvm_nested_guest * gp)833 void kvmhv_put_nested(struct kvm_nested_guest *gp)
834 {
835 	struct kvm *kvm = gp->l1_host;
836 	long ref;
837 
838 	spin_lock(&kvm->mmu_lock);
839 	ref = --gp->refcnt;
840 	spin_unlock(&kvm->mmu_lock);
841 	if (ref == 0)
842 		kvmhv_release_nested(gp);
843 }
844 
kvmhv_find_nested(struct kvm * kvm,int lpid)845 static struct kvm_nested_guest *kvmhv_find_nested(struct kvm *kvm, int lpid)
846 {
847 	if (lpid > kvm->arch.max_nested_lpid)
848 		return NULL;
849 	return kvm->arch.nested_guests[lpid];
850 }
851 
find_kvm_nested_guest_pte(struct kvm * kvm,unsigned long lpid,unsigned long ea,unsigned * hshift)852 pte_t *find_kvm_nested_guest_pte(struct kvm *kvm, unsigned long lpid,
853 				 unsigned long ea, unsigned *hshift)
854 {
855 	struct kvm_nested_guest *gp;
856 	pte_t *pte;
857 
858 	gp = kvmhv_find_nested(kvm, lpid);
859 	if (!gp)
860 		return NULL;
861 
862 	VM_WARN(!spin_is_locked(&kvm->mmu_lock),
863 		"%s called with kvm mmu_lock not held \n", __func__);
864 	pte = __find_linux_pte(gp->shadow_pgtable, ea, NULL, hshift);
865 
866 	return pte;
867 }
868 
kvmhv_n_rmap_is_equal(u64 rmap_1,u64 rmap_2)869 static inline bool kvmhv_n_rmap_is_equal(u64 rmap_1, u64 rmap_2)
870 {
871 	return !((rmap_1 ^ rmap_2) & (RMAP_NESTED_LPID_MASK |
872 				       RMAP_NESTED_GPA_MASK));
873 }
874 
kvmhv_insert_nest_rmap(struct kvm * kvm,unsigned long * rmapp,struct rmap_nested ** n_rmap)875 void kvmhv_insert_nest_rmap(struct kvm *kvm, unsigned long *rmapp,
876 			    struct rmap_nested **n_rmap)
877 {
878 	struct llist_node *entry = ((struct llist_head *) rmapp)->first;
879 	struct rmap_nested *cursor;
880 	u64 rmap, new_rmap = (*n_rmap)->rmap;
881 
882 	/* Are there any existing entries? */
883 	if (!(*rmapp)) {
884 		/* No -> use the rmap as a single entry */
885 		*rmapp = new_rmap | RMAP_NESTED_IS_SINGLE_ENTRY;
886 		return;
887 	}
888 
889 	/* Do any entries match what we're trying to insert? */
890 	for_each_nest_rmap_safe(cursor, entry, &rmap) {
891 		if (kvmhv_n_rmap_is_equal(rmap, new_rmap))
892 			return;
893 	}
894 
895 	/* Do we need to create a list or just add the new entry? */
896 	rmap = *rmapp;
897 	if (rmap & RMAP_NESTED_IS_SINGLE_ENTRY) /* Not previously a list */
898 		*rmapp = 0UL;
899 	llist_add(&((*n_rmap)->list), (struct llist_head *) rmapp);
900 	if (rmap & RMAP_NESTED_IS_SINGLE_ENTRY) /* Not previously a list */
901 		(*n_rmap)->list.next = (struct llist_node *) rmap;
902 
903 	/* Set NULL so not freed by caller */
904 	*n_rmap = NULL;
905 }
906 
kvmhv_update_nest_rmap_rc(struct kvm * kvm,u64 n_rmap,unsigned long clr,unsigned long set,unsigned long hpa,unsigned long mask)907 static void kvmhv_update_nest_rmap_rc(struct kvm *kvm, u64 n_rmap,
908 				      unsigned long clr, unsigned long set,
909 				      unsigned long hpa, unsigned long mask)
910 {
911 	unsigned long gpa;
912 	unsigned int shift, lpid;
913 	pte_t *ptep;
914 
915 	gpa = n_rmap & RMAP_NESTED_GPA_MASK;
916 	lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT;
917 
918 	/* Find the pte */
919 	ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
920 	/*
921 	 * If the pte is present and the pfn is still the same, update the pte.
922 	 * If the pfn has changed then this is a stale rmap entry, the nested
923 	 * gpa actually points somewhere else now, and there is nothing to do.
924 	 * XXX A future optimisation would be to remove the rmap entry here.
925 	 */
926 	if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa)) {
927 		__radix_pte_update(ptep, clr, set);
928 		kvmppc_radix_tlbie_page(kvm, gpa, shift, lpid);
929 	}
930 }
931 
932 /*
933  * For a given list of rmap entries, update the rc bits in all ptes in shadow
934  * page tables for nested guests which are referenced by the rmap list.
935  */
kvmhv_update_nest_rmap_rc_list(struct kvm * kvm,unsigned long * rmapp,unsigned long clr,unsigned long set,unsigned long hpa,unsigned long nbytes)936 void kvmhv_update_nest_rmap_rc_list(struct kvm *kvm, unsigned long *rmapp,
937 				    unsigned long clr, unsigned long set,
938 				    unsigned long hpa, unsigned long nbytes)
939 {
940 	struct llist_node *entry = ((struct llist_head *) rmapp)->first;
941 	struct rmap_nested *cursor;
942 	unsigned long rmap, mask;
943 
944 	if ((clr | set) & ~(_PAGE_DIRTY | _PAGE_ACCESSED))
945 		return;
946 
947 	mask = PTE_RPN_MASK & ~(nbytes - 1);
948 	hpa &= mask;
949 
950 	for_each_nest_rmap_safe(cursor, entry, &rmap)
951 		kvmhv_update_nest_rmap_rc(kvm, rmap, clr, set, hpa, mask);
952 }
953 
kvmhv_remove_nest_rmap(struct kvm * kvm,u64 n_rmap,unsigned long hpa,unsigned long mask)954 static void kvmhv_remove_nest_rmap(struct kvm *kvm, u64 n_rmap,
955 				   unsigned long hpa, unsigned long mask)
956 {
957 	struct kvm_nested_guest *gp;
958 	unsigned long gpa;
959 	unsigned int shift, lpid;
960 	pte_t *ptep;
961 
962 	gpa = n_rmap & RMAP_NESTED_GPA_MASK;
963 	lpid = (n_rmap & RMAP_NESTED_LPID_MASK) >> RMAP_NESTED_LPID_SHIFT;
964 	gp = kvmhv_find_nested(kvm, lpid);
965 	if (!gp)
966 		return;
967 
968 	/* Find and invalidate the pte */
969 	ptep = find_kvm_nested_guest_pte(kvm, lpid, gpa, &shift);
970 	/* Don't spuriously invalidate ptes if the pfn has changed */
971 	if (ptep && pte_present(*ptep) && ((pte_val(*ptep) & mask) == hpa))
972 		kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid);
973 }
974 
kvmhv_remove_nest_rmap_list(struct kvm * kvm,unsigned long * rmapp,unsigned long hpa,unsigned long mask)975 static void kvmhv_remove_nest_rmap_list(struct kvm *kvm, unsigned long *rmapp,
976 					unsigned long hpa, unsigned long mask)
977 {
978 	struct llist_node *entry = llist_del_all((struct llist_head *) rmapp);
979 	struct rmap_nested *cursor;
980 	unsigned long rmap;
981 
982 	for_each_nest_rmap_safe(cursor, entry, &rmap) {
983 		kvmhv_remove_nest_rmap(kvm, rmap, hpa, mask);
984 		kfree(cursor);
985 	}
986 }
987 
988 /* called with kvm->mmu_lock held */
kvmhv_remove_nest_rmap_range(struct kvm * kvm,const struct kvm_memory_slot * memslot,unsigned long gpa,unsigned long hpa,unsigned long nbytes)989 void kvmhv_remove_nest_rmap_range(struct kvm *kvm,
990 				  const struct kvm_memory_slot *memslot,
991 				  unsigned long gpa, unsigned long hpa,
992 				  unsigned long nbytes)
993 {
994 	unsigned long gfn, end_gfn;
995 	unsigned long addr_mask;
996 
997 	if (!memslot)
998 		return;
999 	gfn = (gpa >> PAGE_SHIFT) - memslot->base_gfn;
1000 	end_gfn = gfn + (nbytes >> PAGE_SHIFT);
1001 
1002 	addr_mask = PTE_RPN_MASK & ~(nbytes - 1);
1003 	hpa &= addr_mask;
1004 
1005 	for (; gfn < end_gfn; gfn++) {
1006 		unsigned long *rmap = &memslot->arch.rmap[gfn];
1007 		kvmhv_remove_nest_rmap_list(kvm, rmap, hpa, addr_mask);
1008 	}
1009 }
1010 
kvmhv_free_memslot_nest_rmap(struct kvm_memory_slot * free)1011 static void kvmhv_free_memslot_nest_rmap(struct kvm_memory_slot *free)
1012 {
1013 	unsigned long page;
1014 
1015 	for (page = 0; page < free->npages; page++) {
1016 		unsigned long rmap, *rmapp = &free->arch.rmap[page];
1017 		struct rmap_nested *cursor;
1018 		struct llist_node *entry;
1019 
1020 		entry = llist_del_all((struct llist_head *) rmapp);
1021 		for_each_nest_rmap_safe(cursor, entry, &rmap)
1022 			kfree(cursor);
1023 	}
1024 }
1025 
kvmhv_invalidate_shadow_pte(struct kvm_vcpu * vcpu,struct kvm_nested_guest * gp,long gpa,int * shift_ret)1026 static bool kvmhv_invalidate_shadow_pte(struct kvm_vcpu *vcpu,
1027 					struct kvm_nested_guest *gp,
1028 					long gpa, int *shift_ret)
1029 {
1030 	struct kvm *kvm = vcpu->kvm;
1031 	bool ret = false;
1032 	pte_t *ptep;
1033 	int shift;
1034 
1035 	spin_lock(&kvm->mmu_lock);
1036 	ptep = find_kvm_nested_guest_pte(kvm, gp->l1_lpid, gpa, &shift);
1037 	if (!shift)
1038 		shift = PAGE_SHIFT;
1039 	if (ptep && pte_present(*ptep)) {
1040 		kvmppc_unmap_pte(kvm, ptep, gpa, shift, NULL, gp->shadow_lpid);
1041 		ret = true;
1042 	}
1043 	spin_unlock(&kvm->mmu_lock);
1044 
1045 	if (shift_ret)
1046 		*shift_ret = shift;
1047 	return ret;
1048 }
1049 
get_ric(unsigned int instr)1050 static inline int get_ric(unsigned int instr)
1051 {
1052 	return (instr >> 18) & 0x3;
1053 }
1054 
get_prs(unsigned int instr)1055 static inline int get_prs(unsigned int instr)
1056 {
1057 	return (instr >> 17) & 0x1;
1058 }
1059 
get_r(unsigned int instr)1060 static inline int get_r(unsigned int instr)
1061 {
1062 	return (instr >> 16) & 0x1;
1063 }
1064 
get_lpid(unsigned long r_val)1065 static inline int get_lpid(unsigned long r_val)
1066 {
1067 	return r_val & 0xffffffff;
1068 }
1069 
get_is(unsigned long r_val)1070 static inline int get_is(unsigned long r_val)
1071 {
1072 	return (r_val >> 10) & 0x3;
1073 }
1074 
get_ap(unsigned long r_val)1075 static inline int get_ap(unsigned long r_val)
1076 {
1077 	return (r_val >> 5) & 0x7;
1078 }
1079 
get_epn(unsigned long r_val)1080 static inline long get_epn(unsigned long r_val)
1081 {
1082 	return r_val >> 12;
1083 }
1084 
kvmhv_emulate_tlbie_tlb_addr(struct kvm_vcpu * vcpu,int lpid,int ap,long epn)1085 static int kvmhv_emulate_tlbie_tlb_addr(struct kvm_vcpu *vcpu, int lpid,
1086 					int ap, long epn)
1087 {
1088 	struct kvm *kvm = vcpu->kvm;
1089 	struct kvm_nested_guest *gp;
1090 	long npages;
1091 	int shift, shadow_shift;
1092 	unsigned long addr;
1093 
1094 	shift = ap_to_shift(ap);
1095 	addr = epn << 12;
1096 	if (shift < 0)
1097 		/* Invalid ap encoding */
1098 		return -EINVAL;
1099 
1100 	addr &= ~((1UL << shift) - 1);
1101 	npages = 1UL << (shift - PAGE_SHIFT);
1102 
1103 	gp = kvmhv_get_nested(kvm, lpid, false);
1104 	if (!gp) /* No such guest -> nothing to do */
1105 		return 0;
1106 	mutex_lock(&gp->tlb_lock);
1107 
1108 	/* There may be more than one host page backing this single guest pte */
1109 	do {
1110 		kvmhv_invalidate_shadow_pte(vcpu, gp, addr, &shadow_shift);
1111 
1112 		npages -= 1UL << (shadow_shift - PAGE_SHIFT);
1113 		addr += 1UL << shadow_shift;
1114 	} while (npages > 0);
1115 
1116 	mutex_unlock(&gp->tlb_lock);
1117 	kvmhv_put_nested(gp);
1118 	return 0;
1119 }
1120 
kvmhv_emulate_tlbie_lpid(struct kvm_vcpu * vcpu,struct kvm_nested_guest * gp,int ric)1121 static void kvmhv_emulate_tlbie_lpid(struct kvm_vcpu *vcpu,
1122 				     struct kvm_nested_guest *gp, int ric)
1123 {
1124 	struct kvm *kvm = vcpu->kvm;
1125 
1126 	mutex_lock(&gp->tlb_lock);
1127 	switch (ric) {
1128 	case 0:
1129 		/* Invalidate TLB */
1130 		spin_lock(&kvm->mmu_lock);
1131 		kvmppc_free_pgtable_radix(kvm, gp->shadow_pgtable,
1132 					  gp->shadow_lpid);
1133 		kvmhv_flush_lpid(gp->shadow_lpid);
1134 		spin_unlock(&kvm->mmu_lock);
1135 		break;
1136 	case 1:
1137 		/*
1138 		 * Invalidate PWC
1139 		 * We don't cache this -> nothing to do
1140 		 */
1141 		break;
1142 	case 2:
1143 		/* Invalidate TLB, PWC and caching of partition table entries */
1144 		kvmhv_flush_nested(gp);
1145 		break;
1146 	default:
1147 		break;
1148 	}
1149 	mutex_unlock(&gp->tlb_lock);
1150 }
1151 
kvmhv_emulate_tlbie_all_lpid(struct kvm_vcpu * vcpu,int ric)1152 static void kvmhv_emulate_tlbie_all_lpid(struct kvm_vcpu *vcpu, int ric)
1153 {
1154 	struct kvm *kvm = vcpu->kvm;
1155 	struct kvm_nested_guest *gp;
1156 	int i;
1157 
1158 	spin_lock(&kvm->mmu_lock);
1159 	for (i = 0; i <= kvm->arch.max_nested_lpid; i++) {
1160 		gp = kvm->arch.nested_guests[i];
1161 		if (gp) {
1162 			spin_unlock(&kvm->mmu_lock);
1163 			kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
1164 			spin_lock(&kvm->mmu_lock);
1165 		}
1166 	}
1167 	spin_unlock(&kvm->mmu_lock);
1168 }
1169 
kvmhv_emulate_priv_tlbie(struct kvm_vcpu * vcpu,unsigned int instr,unsigned long rsval,unsigned long rbval)1170 static int kvmhv_emulate_priv_tlbie(struct kvm_vcpu *vcpu, unsigned int instr,
1171 				    unsigned long rsval, unsigned long rbval)
1172 {
1173 	struct kvm *kvm = vcpu->kvm;
1174 	struct kvm_nested_guest *gp;
1175 	int r, ric, prs, is, ap;
1176 	int lpid;
1177 	long epn;
1178 	int ret = 0;
1179 
1180 	ric = get_ric(instr);
1181 	prs = get_prs(instr);
1182 	r = get_r(instr);
1183 	lpid = get_lpid(rsval);
1184 	is = get_is(rbval);
1185 
1186 	/*
1187 	 * These cases are invalid and are not handled:
1188 	 * r   != 1 -> Only radix supported
1189 	 * prs == 1 -> Not HV privileged
1190 	 * ric == 3 -> No cluster bombs for radix
1191 	 * is  == 1 -> Partition scoped translations not associated with pid
1192 	 * (!is) && (ric == 1 || ric == 2) -> Not supported by ISA
1193 	 */
1194 	if ((!r) || (prs) || (ric == 3) || (is == 1) ||
1195 	    ((!is) && (ric == 1 || ric == 2)))
1196 		return -EINVAL;
1197 
1198 	switch (is) {
1199 	case 0:
1200 		/*
1201 		 * We know ric == 0
1202 		 * Invalidate TLB for a given target address
1203 		 */
1204 		epn = get_epn(rbval);
1205 		ap = get_ap(rbval);
1206 		ret = kvmhv_emulate_tlbie_tlb_addr(vcpu, lpid, ap, epn);
1207 		break;
1208 	case 2:
1209 		/* Invalidate matching LPID */
1210 		gp = kvmhv_get_nested(kvm, lpid, false);
1211 		if (gp) {
1212 			kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
1213 			kvmhv_put_nested(gp);
1214 		}
1215 		break;
1216 	case 3:
1217 		/* Invalidate ALL LPIDs */
1218 		kvmhv_emulate_tlbie_all_lpid(vcpu, ric);
1219 		break;
1220 	default:
1221 		ret = -EINVAL;
1222 		break;
1223 	}
1224 
1225 	return ret;
1226 }
1227 
1228 /*
1229  * This handles the H_TLB_INVALIDATE hcall.
1230  * Parameters are (r4) tlbie instruction code, (r5) rS contents,
1231  * (r6) rB contents.
1232  */
kvmhv_do_nested_tlbie(struct kvm_vcpu * vcpu)1233 long kvmhv_do_nested_tlbie(struct kvm_vcpu *vcpu)
1234 {
1235 	int ret;
1236 
1237 	ret = kvmhv_emulate_priv_tlbie(vcpu, kvmppc_get_gpr(vcpu, 4),
1238 			kvmppc_get_gpr(vcpu, 5), kvmppc_get_gpr(vcpu, 6));
1239 	if (ret)
1240 		return H_PARAMETER;
1241 	return H_SUCCESS;
1242 }
1243 
do_tlb_invalidate_nested_all(struct kvm_vcpu * vcpu,unsigned long lpid,unsigned long ric)1244 static long do_tlb_invalidate_nested_all(struct kvm_vcpu *vcpu,
1245 					 unsigned long lpid, unsigned long ric)
1246 {
1247 	struct kvm *kvm = vcpu->kvm;
1248 	struct kvm_nested_guest *gp;
1249 
1250 	gp = kvmhv_get_nested(kvm, lpid, false);
1251 	if (gp) {
1252 		kvmhv_emulate_tlbie_lpid(vcpu, gp, ric);
1253 		kvmhv_put_nested(gp);
1254 	}
1255 	return H_SUCCESS;
1256 }
1257 
1258 /*
1259  * Number of pages above which we invalidate the entire LPID rather than
1260  * flush individual pages.
1261  */
1262 static unsigned long tlb_range_flush_page_ceiling __read_mostly = 33;
1263 
do_tlb_invalidate_nested_tlb(struct kvm_vcpu * vcpu,unsigned long lpid,unsigned long pg_sizes,unsigned long start,unsigned long end)1264 static long do_tlb_invalidate_nested_tlb(struct kvm_vcpu *vcpu,
1265 					 unsigned long lpid,
1266 					 unsigned long pg_sizes,
1267 					 unsigned long start,
1268 					 unsigned long end)
1269 {
1270 	int ret = H_P4;
1271 	unsigned long addr, nr_pages;
1272 	struct mmu_psize_def *def;
1273 	unsigned long psize, ap, page_size;
1274 	bool flush_lpid;
1275 
1276 	for (psize = 0; psize < MMU_PAGE_COUNT; psize++) {
1277 		def = &mmu_psize_defs[psize];
1278 		if (!(pg_sizes & def->h_rpt_pgsize))
1279 			continue;
1280 
1281 		nr_pages = (end - start) >> def->shift;
1282 		flush_lpid = nr_pages > tlb_range_flush_page_ceiling;
1283 		if (flush_lpid)
1284 			return do_tlb_invalidate_nested_all(vcpu, lpid,
1285 							RIC_FLUSH_TLB);
1286 		addr = start;
1287 		ap = mmu_get_ap(psize);
1288 		page_size = 1UL << def->shift;
1289 		do {
1290 			ret = kvmhv_emulate_tlbie_tlb_addr(vcpu, lpid, ap,
1291 						   get_epn(addr));
1292 			if (ret)
1293 				return H_P4;
1294 			addr += page_size;
1295 		} while (addr < end);
1296 	}
1297 	return ret;
1298 }
1299 
1300 /*
1301  * Performs partition-scoped invalidations for nested guests
1302  * as part of H_RPT_INVALIDATE hcall.
1303  */
do_h_rpt_invalidate_pat(struct kvm_vcpu * vcpu,unsigned long lpid,unsigned long type,unsigned long pg_sizes,unsigned long start,unsigned long end)1304 long do_h_rpt_invalidate_pat(struct kvm_vcpu *vcpu, unsigned long lpid,
1305 			     unsigned long type, unsigned long pg_sizes,
1306 			     unsigned long start, unsigned long end)
1307 {
1308 	/*
1309 	 * If L2 lpid isn't valid, we need to return H_PARAMETER.
1310 	 *
1311 	 * However, nested KVM issues a L2 lpid flush call when creating
1312 	 * partition table entries for L2. This happens even before the
1313 	 * corresponding shadow lpid is created in HV which happens in
1314 	 * H_ENTER_NESTED call. Since we can't differentiate this case from
1315 	 * the invalid case, we ignore such flush requests and return success.
1316 	 */
1317 	if (!kvmhv_find_nested(vcpu->kvm, lpid))
1318 		return H_SUCCESS;
1319 
1320 	/*
1321 	 * A flush all request can be handled by a full lpid flush only.
1322 	 */
1323 	if ((type & H_RPTI_TYPE_NESTED_ALL) == H_RPTI_TYPE_NESTED_ALL)
1324 		return do_tlb_invalidate_nested_all(vcpu, lpid, RIC_FLUSH_ALL);
1325 
1326 	/*
1327 	 * We don't need to handle a PWC flush like process table here,
1328 	 * because intermediate partition scoped table in nested guest doesn't
1329 	 * really have PWC. Only level we have PWC is in L0 and for nested
1330 	 * invalidate at L0 we always do kvm_flush_lpid() which does
1331 	 * radix__flush_all_lpid(). For range invalidate at any level, we
1332 	 * are not removing the higher level page tables and hence there is
1333 	 * no PWC invalidate needed.
1334 	 *
1335 	 * if (type & H_RPTI_TYPE_PWC) {
1336 	 *	ret = do_tlb_invalidate_nested_all(vcpu, lpid, RIC_FLUSH_PWC);
1337 	 *	if (ret)
1338 	 *		return H_P4;
1339 	 * }
1340 	 */
1341 
1342 	if (start == 0 && end == -1)
1343 		return do_tlb_invalidate_nested_all(vcpu, lpid, RIC_FLUSH_TLB);
1344 
1345 	if (type & H_RPTI_TYPE_TLB)
1346 		return do_tlb_invalidate_nested_tlb(vcpu, lpid, pg_sizes,
1347 						    start, end);
1348 	return H_SUCCESS;
1349 }
1350 
1351 /* Used to convert a nested guest real address to a L1 guest real address */
kvmhv_translate_addr_nested(struct kvm_vcpu * vcpu,struct kvm_nested_guest * gp,unsigned long n_gpa,unsigned long dsisr,struct kvmppc_pte * gpte_p)1352 static int kvmhv_translate_addr_nested(struct kvm_vcpu *vcpu,
1353 				       struct kvm_nested_guest *gp,
1354 				       unsigned long n_gpa, unsigned long dsisr,
1355 				       struct kvmppc_pte *gpte_p)
1356 {
1357 	u64 fault_addr, flags = dsisr & DSISR_ISSTORE;
1358 	int ret;
1359 
1360 	ret = kvmppc_mmu_walk_radix_tree(vcpu, n_gpa, gpte_p, gp->l1_gr_to_hr,
1361 					 &fault_addr);
1362 
1363 	if (ret) {
1364 		/* We didn't find a pte */
1365 		if (ret == -EINVAL) {
1366 			/* Unsupported mmu config */
1367 			flags |= DSISR_UNSUPP_MMU;
1368 		} else if (ret == -ENOENT) {
1369 			/* No translation found */
1370 			flags |= DSISR_NOHPTE;
1371 		} else if (ret == -EFAULT) {
1372 			/* Couldn't access L1 real address */
1373 			flags |= DSISR_PRTABLE_FAULT;
1374 			vcpu->arch.fault_gpa = fault_addr;
1375 		} else {
1376 			/* Unknown error */
1377 			return ret;
1378 		}
1379 		goto forward_to_l1;
1380 	} else {
1381 		/* We found a pte -> check permissions */
1382 		if (dsisr & DSISR_ISSTORE) {
1383 			/* Can we write? */
1384 			if (!gpte_p->may_write) {
1385 				flags |= DSISR_PROTFAULT;
1386 				goto forward_to_l1;
1387 			}
1388 		} else if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
1389 			/* Can we execute? */
1390 			if (!gpte_p->may_execute) {
1391 				flags |= SRR1_ISI_N_G_OR_CIP;
1392 				goto forward_to_l1;
1393 			}
1394 		} else {
1395 			/* Can we read? */
1396 			if (!gpte_p->may_read && !gpte_p->may_write) {
1397 				flags |= DSISR_PROTFAULT;
1398 				goto forward_to_l1;
1399 			}
1400 		}
1401 	}
1402 
1403 	return 0;
1404 
1405 forward_to_l1:
1406 	vcpu->arch.fault_dsisr = flags;
1407 	if (vcpu->arch.trap == BOOK3S_INTERRUPT_H_INST_STORAGE) {
1408 		vcpu->arch.shregs.msr &= SRR1_MSR_BITS;
1409 		vcpu->arch.shregs.msr |= flags;
1410 	}
1411 	return RESUME_HOST;
1412 }
1413 
kvmhv_handle_nested_set_rc(struct kvm_vcpu * vcpu,struct kvm_nested_guest * gp,unsigned long n_gpa,struct kvmppc_pte gpte,unsigned long dsisr)1414 static long kvmhv_handle_nested_set_rc(struct kvm_vcpu *vcpu,
1415 				       struct kvm_nested_guest *gp,
1416 				       unsigned long n_gpa,
1417 				       struct kvmppc_pte gpte,
1418 				       unsigned long dsisr)
1419 {
1420 	struct kvm *kvm = vcpu->kvm;
1421 	bool writing = !!(dsisr & DSISR_ISSTORE);
1422 	u64 pgflags;
1423 	long ret;
1424 
1425 	/* Are the rc bits set in the L1 partition scoped pte? */
1426 	pgflags = _PAGE_ACCESSED;
1427 	if (writing)
1428 		pgflags |= _PAGE_DIRTY;
1429 	if (pgflags & ~gpte.rc)
1430 		return RESUME_HOST;
1431 
1432 	spin_lock(&kvm->mmu_lock);
1433 	/* Set the rc bit in the pte of our (L0) pgtable for the L1 guest */
1434 	ret = kvmppc_hv_handle_set_rc(kvm, false, writing,
1435 				      gpte.raddr, kvm->arch.lpid);
1436 	if (!ret) {
1437 		ret = -EINVAL;
1438 		goto out_unlock;
1439 	}
1440 
1441 	/* Set the rc bit in the pte of the shadow_pgtable for the nest guest */
1442 	ret = kvmppc_hv_handle_set_rc(kvm, true, writing,
1443 				      n_gpa, gp->l1_lpid);
1444 	if (!ret)
1445 		ret = -EINVAL;
1446 	else
1447 		ret = 0;
1448 
1449 out_unlock:
1450 	spin_unlock(&kvm->mmu_lock);
1451 	return ret;
1452 }
1453 
kvmppc_radix_level_to_shift(int level)1454 static inline int kvmppc_radix_level_to_shift(int level)
1455 {
1456 	switch (level) {
1457 	case 2:
1458 		return PUD_SHIFT;
1459 	case 1:
1460 		return PMD_SHIFT;
1461 	default:
1462 		return PAGE_SHIFT;
1463 	}
1464 }
1465 
kvmppc_radix_shift_to_level(int shift)1466 static inline int kvmppc_radix_shift_to_level(int shift)
1467 {
1468 	if (shift == PUD_SHIFT)
1469 		return 2;
1470 	if (shift == PMD_SHIFT)
1471 		return 1;
1472 	if (shift == PAGE_SHIFT)
1473 		return 0;
1474 	WARN_ON_ONCE(1);
1475 	return 0;
1476 }
1477 
1478 /* called with gp->tlb_lock held */
__kvmhv_nested_page_fault(struct kvm_vcpu * vcpu,struct kvm_nested_guest * gp)1479 static long int __kvmhv_nested_page_fault(struct kvm_vcpu *vcpu,
1480 					  struct kvm_nested_guest *gp)
1481 {
1482 	struct kvm *kvm = vcpu->kvm;
1483 	struct kvm_memory_slot *memslot;
1484 	struct rmap_nested *n_rmap;
1485 	struct kvmppc_pte gpte;
1486 	pte_t pte, *pte_p;
1487 	unsigned long mmu_seq;
1488 	unsigned long dsisr = vcpu->arch.fault_dsisr;
1489 	unsigned long ea = vcpu->arch.fault_dar;
1490 	unsigned long *rmapp;
1491 	unsigned long n_gpa, gpa, gfn, perm = 0UL;
1492 	unsigned int shift, l1_shift, level;
1493 	bool writing = !!(dsisr & DSISR_ISSTORE);
1494 	bool kvm_ro = false;
1495 	long int ret;
1496 
1497 	if (!gp->l1_gr_to_hr) {
1498 		kvmhv_update_ptbl_cache(gp);
1499 		if (!gp->l1_gr_to_hr)
1500 			return RESUME_HOST;
1501 	}
1502 
1503 	/* Convert the nested guest real address into a L1 guest real address */
1504 
1505 	n_gpa = vcpu->arch.fault_gpa & ~0xF000000000000FFFULL;
1506 	if (!(dsisr & DSISR_PRTABLE_FAULT))
1507 		n_gpa |= ea & 0xFFF;
1508 	ret = kvmhv_translate_addr_nested(vcpu, gp, n_gpa, dsisr, &gpte);
1509 
1510 	/*
1511 	 * If the hardware found a translation but we don't now have a usable
1512 	 * translation in the l1 partition-scoped tree, remove the shadow pte
1513 	 * and let the guest retry.
1514 	 */
1515 	if (ret == RESUME_HOST &&
1516 	    (dsisr & (DSISR_PROTFAULT | DSISR_BADACCESS | DSISR_NOEXEC_OR_G |
1517 		      DSISR_BAD_COPYPASTE)))
1518 		goto inval;
1519 	if (ret)
1520 		return ret;
1521 
1522 	/* Failed to set the reference/change bits */
1523 	if (dsisr & DSISR_SET_RC) {
1524 		ret = kvmhv_handle_nested_set_rc(vcpu, gp, n_gpa, gpte, dsisr);
1525 		if (ret == RESUME_HOST)
1526 			return ret;
1527 		if (ret)
1528 			goto inval;
1529 		dsisr &= ~DSISR_SET_RC;
1530 		if (!(dsisr & (DSISR_BAD_FAULT_64S | DSISR_NOHPTE |
1531 			       DSISR_PROTFAULT)))
1532 			return RESUME_GUEST;
1533 	}
1534 
1535 	/*
1536 	 * We took an HISI or HDSI while we were running a nested guest which
1537 	 * means we have no partition scoped translation for that. This means
1538 	 * we need to insert a pte for the mapping into our shadow_pgtable.
1539 	 */
1540 
1541 	l1_shift = gpte.page_shift;
1542 	if (l1_shift < PAGE_SHIFT) {
1543 		/* We don't support l1 using a page size smaller than our own */
1544 		pr_err("KVM: L1 guest page shift (%d) less than our own (%d)\n",
1545 			l1_shift, PAGE_SHIFT);
1546 		return -EINVAL;
1547 	}
1548 	gpa = gpte.raddr;
1549 	gfn = gpa >> PAGE_SHIFT;
1550 
1551 	/* 1. Get the corresponding host memslot */
1552 
1553 	memslot = gfn_to_memslot(kvm, gfn);
1554 	if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) {
1555 		if (dsisr & (DSISR_PRTABLE_FAULT | DSISR_BADACCESS)) {
1556 			/* unusual error -> reflect to the guest as a DSI */
1557 			kvmppc_core_queue_data_storage(vcpu, ea, dsisr);
1558 			return RESUME_GUEST;
1559 		}
1560 
1561 		/* passthrough of emulated MMIO case */
1562 		return kvmppc_hv_emulate_mmio(vcpu, gpa, ea, writing);
1563 	}
1564 	if (memslot->flags & KVM_MEM_READONLY) {
1565 		if (writing) {
1566 			/* Give the guest a DSI */
1567 			kvmppc_core_queue_data_storage(vcpu, ea,
1568 					DSISR_ISSTORE | DSISR_PROTFAULT);
1569 			return RESUME_GUEST;
1570 		}
1571 		kvm_ro = true;
1572 	}
1573 
1574 	/* 2. Find the host pte for this L1 guest real address */
1575 
1576 	/* Used to check for invalidations in progress */
1577 	mmu_seq = kvm->mmu_notifier_seq;
1578 	smp_rmb();
1579 
1580 	/* See if can find translation in our partition scoped tables for L1 */
1581 	pte = __pte(0);
1582 	spin_lock(&kvm->mmu_lock);
1583 	pte_p = find_kvm_secondary_pte(kvm, gpa, &shift);
1584 	if (!shift)
1585 		shift = PAGE_SHIFT;
1586 	if (pte_p)
1587 		pte = *pte_p;
1588 	spin_unlock(&kvm->mmu_lock);
1589 
1590 	if (!pte_present(pte) || (writing && !(pte_val(pte) & _PAGE_WRITE))) {
1591 		/* No suitable pte found -> try to insert a mapping */
1592 		ret = kvmppc_book3s_instantiate_page(vcpu, gpa, memslot,
1593 					writing, kvm_ro, &pte, &level);
1594 		if (ret == -EAGAIN)
1595 			return RESUME_GUEST;
1596 		else if (ret)
1597 			return ret;
1598 		shift = kvmppc_radix_level_to_shift(level);
1599 	}
1600 	/* Align gfn to the start of the page */
1601 	gfn = (gpa & ~((1UL << shift) - 1)) >> PAGE_SHIFT;
1602 
1603 	/* 3. Compute the pte we need to insert for nest_gpa -> host r_addr */
1604 
1605 	/* The permissions is the combination of the host and l1 guest ptes */
1606 	perm |= gpte.may_read ? 0UL : _PAGE_READ;
1607 	perm |= gpte.may_write ? 0UL : _PAGE_WRITE;
1608 	perm |= gpte.may_execute ? 0UL : _PAGE_EXEC;
1609 	/* Only set accessed/dirty (rc) bits if set in host and l1 guest ptes */
1610 	perm |= (gpte.rc & _PAGE_ACCESSED) ? 0UL : _PAGE_ACCESSED;
1611 	perm |= ((gpte.rc & _PAGE_DIRTY) && writing) ? 0UL : _PAGE_DIRTY;
1612 	pte = __pte(pte_val(pte) & ~perm);
1613 
1614 	/* What size pte can we insert? */
1615 	if (shift > l1_shift) {
1616 		u64 mask;
1617 		unsigned int actual_shift = PAGE_SHIFT;
1618 		if (PMD_SHIFT < l1_shift)
1619 			actual_shift = PMD_SHIFT;
1620 		mask = (1UL << shift) - (1UL << actual_shift);
1621 		pte = __pte(pte_val(pte) | (gpa & mask));
1622 		shift = actual_shift;
1623 	}
1624 	level = kvmppc_radix_shift_to_level(shift);
1625 	n_gpa &= ~((1UL << shift) - 1);
1626 
1627 	/* 4. Insert the pte into our shadow_pgtable */
1628 
1629 	n_rmap = kzalloc(sizeof(*n_rmap), GFP_KERNEL);
1630 	if (!n_rmap)
1631 		return RESUME_GUEST; /* Let the guest try again */
1632 	n_rmap->rmap = (n_gpa & RMAP_NESTED_GPA_MASK) |
1633 		(((unsigned long) gp->l1_lpid) << RMAP_NESTED_LPID_SHIFT);
1634 	rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn];
1635 	ret = kvmppc_create_pte(kvm, gp->shadow_pgtable, pte, n_gpa, level,
1636 				mmu_seq, gp->shadow_lpid, rmapp, &n_rmap);
1637 	kfree(n_rmap);
1638 	if (ret == -EAGAIN)
1639 		ret = RESUME_GUEST;	/* Let the guest try again */
1640 
1641 	return ret;
1642 
1643  inval:
1644 	kvmhv_invalidate_shadow_pte(vcpu, gp, n_gpa, NULL);
1645 	return RESUME_GUEST;
1646 }
1647 
kvmhv_nested_page_fault(struct kvm_vcpu * vcpu)1648 long int kvmhv_nested_page_fault(struct kvm_vcpu *vcpu)
1649 {
1650 	struct kvm_nested_guest *gp = vcpu->arch.nested;
1651 	long int ret;
1652 
1653 	mutex_lock(&gp->tlb_lock);
1654 	ret = __kvmhv_nested_page_fault(vcpu, gp);
1655 	mutex_unlock(&gp->tlb_lock);
1656 	return ret;
1657 }
1658 
kvmhv_nested_next_lpid(struct kvm * kvm,int lpid)1659 int kvmhv_nested_next_lpid(struct kvm *kvm, int lpid)
1660 {
1661 	int ret = -1;
1662 
1663 	spin_lock(&kvm->mmu_lock);
1664 	while (++lpid <= kvm->arch.max_nested_lpid) {
1665 		if (kvm->arch.nested_guests[lpid]) {
1666 			ret = lpid;
1667 			break;
1668 		}
1669 	}
1670 	spin_unlock(&kvm->mmu_lock);
1671 	return ret;
1672 }
1673