1 /*
2  * Copyright (C) 2009 SUSE Linux Products GmbH. All rights reserved.
3  *
4  * Authors:
5  *     Alexander Graf <agraf@suse.de>
6  *     Kevin Wolf <mail@kevin-wolf.de>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License, version 2, as
10  * published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
20  */
21 
22 #include <linux/kvm_host.h>
23 
24 #include <asm/kvm_ppc.h>
25 #include <asm/kvm_book3s.h>
26 #include <asm/book3s/64/mmu-hash.h>
27 #include <asm/machdep.h>
28 #include <asm/mmu_context.h>
29 #include <asm/hw_irq.h>
30 #include "trace_pr.h"
31 #include "book3s.h"
32 
33 #define PTE_SIZE 12
34 
35 void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
36 {
37 	mmu_hash_ops.hpte_invalidate(pte->slot, pte->host_vpn,
38 				     pte->pagesize, pte->pagesize,
39 				     MMU_SEGSIZE_256M, false);
40 }
41 
42 /* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
43  * a hash, so we don't waste cycles on looping */
44 static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
45 {
46 	return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
47 		     ((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
48 		     ((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
49 		     ((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
50 		     ((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
51 		     ((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
52 		     ((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
53 		     ((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
54 }
55 
56 
57 static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
58 {
59 	struct kvmppc_sid_map *map;
60 	u16 sid_map_mask;
61 
62 	if (kvmppc_get_msr(vcpu) & MSR_PR)
63 		gvsid |= VSID_PR;
64 
65 	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
66 	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
67 	if (map->valid && (map->guest_vsid == gvsid)) {
68 		trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
69 		return map;
70 	}
71 
72 	map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
73 	if (map->valid && (map->guest_vsid == gvsid)) {
74 		trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
75 		return map;
76 	}
77 
78 	trace_kvm_book3s_slb_fail(sid_map_mask, gvsid);
79 	return NULL;
80 }
81 
82 int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
83 			bool iswrite)
84 {
85 	unsigned long vpn;
86 	kvm_pfn_t hpaddr;
87 	ulong hash, hpteg;
88 	u64 vsid;
89 	int ret;
90 	int rflags = 0x192;
91 	int vflags = 0;
92 	int attempt = 0;
93 	struct kvmppc_sid_map *map;
94 	int r = 0;
95 	int hpsize = MMU_PAGE_4K;
96 	bool writable;
97 	unsigned long mmu_seq;
98 	struct kvm *kvm = vcpu->kvm;
99 	struct hpte_cache *cpte;
100 	unsigned long gfn = orig_pte->raddr >> PAGE_SHIFT;
101 	unsigned long pfn;
102 
103 	/* used to check for invalidations in progress */
104 	mmu_seq = kvm->mmu_notifier_seq;
105 	smp_rmb();
106 
107 	/* Get host physical address for gpa */
108 	pfn = kvmppc_gpa_to_pfn(vcpu, orig_pte->raddr, iswrite, &writable);
109 	if (is_error_noslot_pfn(pfn)) {
110 		printk(KERN_INFO "Couldn't get guest page for gpa %lx!\n",
111 		       orig_pte->raddr);
112 		r = -EINVAL;
113 		goto out;
114 	}
115 	hpaddr = pfn << PAGE_SHIFT;
116 
117 	/* and write the mapping ea -> hpa into the pt */
118 	vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
119 	map = find_sid_vsid(vcpu, vsid);
120 	if (!map) {
121 		ret = kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
122 		WARN_ON(ret < 0);
123 		map = find_sid_vsid(vcpu, vsid);
124 	}
125 	if (!map) {
126 		printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",
127 				vsid, orig_pte->eaddr);
128 		WARN_ON(true);
129 		r = -EINVAL;
130 		goto out;
131 	}
132 
133 	vpn = hpt_vpn(orig_pte->eaddr, map->host_vsid, MMU_SEGSIZE_256M);
134 
135 	kvm_set_pfn_accessed(pfn);
136 	if (!orig_pte->may_write || !writable)
137 		rflags |= PP_RXRX;
138 	else {
139 		mark_page_dirty(vcpu->kvm, gfn);
140 		kvm_set_pfn_dirty(pfn);
141 	}
142 
143 	if (!orig_pte->may_execute)
144 		rflags |= HPTE_R_N;
145 	else
146 		kvmppc_mmu_flush_icache(pfn);
147 
148 	rflags = (rflags & ~HPTE_R_WIMG) | orig_pte->wimg;
149 
150 	/*
151 	 * Use 64K pages if possible; otherwise, on 64K page kernels,
152 	 * we need to transfer 4 more bits from guest real to host real addr.
153 	 */
154 	if (vsid & VSID_64K)
155 		hpsize = MMU_PAGE_64K;
156 	else
157 		hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
158 
159 	hash = hpt_hash(vpn, mmu_psize_defs[hpsize].shift, MMU_SEGSIZE_256M);
160 
161 	cpte = kvmppc_mmu_hpte_cache_next(vcpu);
162 
163 	spin_lock(&kvm->mmu_lock);
164 	if (!cpte || mmu_notifier_retry(kvm, mmu_seq)) {
165 		r = -EAGAIN;
166 		goto out_unlock;
167 	}
168 
169 map_again:
170 	hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
171 
172 	/* In case we tried normal mapping already, let's nuke old entries */
173 	if (attempt > 1)
174 		if (mmu_hash_ops.hpte_remove(hpteg) < 0) {
175 			r = -1;
176 			goto out_unlock;
177 		}
178 
179 	ret = mmu_hash_ops.hpte_insert(hpteg, vpn, hpaddr, rflags, vflags,
180 				       hpsize, hpsize, MMU_SEGSIZE_256M);
181 
182 	if (ret == -1) {
183 		/* If we couldn't map a primary PTE, try a secondary */
184 		hash = ~hash;
185 		vflags ^= HPTE_V_SECONDARY;
186 		attempt++;
187 		goto map_again;
188 	} else if (ret < 0) {
189 		r = -EIO;
190 		goto out_unlock;
191 	} else {
192 		trace_kvm_book3s_64_mmu_map(rflags, hpteg,
193 					    vpn, hpaddr, orig_pte);
194 
195 		/*
196 		 * The mmu_hash_ops code may give us a secondary entry even
197 		 * though we asked for a primary. Fix up.
198 		 */
199 		if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
200 			hash = ~hash;
201 			hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
202 		}
203 
204 		cpte->slot = hpteg + (ret & 7);
205 		cpte->host_vpn = vpn;
206 		cpte->pte = *orig_pte;
207 		cpte->pfn = pfn;
208 		cpte->pagesize = hpsize;
209 
210 		kvmppc_mmu_hpte_cache_map(vcpu, cpte);
211 		cpte = NULL;
212 	}
213 
214 out_unlock:
215 	spin_unlock(&kvm->mmu_lock);
216 	kvm_release_pfn_clean(pfn);
217 	if (cpte)
218 		kvmppc_mmu_hpte_cache_free(cpte);
219 
220 out:
221 	return r;
222 }
223 
224 void kvmppc_mmu_unmap_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
225 {
226 	u64 mask = 0xfffffffffULL;
227 	u64 vsid;
228 
229 	vcpu->arch.mmu.esid_to_vsid(vcpu, pte->eaddr >> SID_SHIFT, &vsid);
230 	if (vsid & VSID_64K)
231 		mask = 0xffffffff0ULL;
232 	kvmppc_mmu_pte_vflush(vcpu, pte->vpage, mask);
233 }
234 
235 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
236 {
237 	unsigned long vsid_bits = VSID_BITS_65_256M;
238 	struct kvmppc_sid_map *map;
239 	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
240 	u16 sid_map_mask;
241 	static int backwards_map = 0;
242 
243 	if (kvmppc_get_msr(vcpu) & MSR_PR)
244 		gvsid |= VSID_PR;
245 
246 	/* We might get collisions that trap in preceding order, so let's
247 	   map them differently */
248 
249 	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
250 	if (backwards_map)
251 		sid_map_mask = SID_MAP_MASK - sid_map_mask;
252 
253 	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
254 
255 	/* Make sure we're taking the other map next time */
256 	backwards_map = !backwards_map;
257 
258 	/* Uh-oh ... out of mappings. Let's flush! */
259 	if (vcpu_book3s->proto_vsid_next == vcpu_book3s->proto_vsid_max) {
260 		vcpu_book3s->proto_vsid_next = vcpu_book3s->proto_vsid_first;
261 		memset(vcpu_book3s->sid_map, 0,
262 		       sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
263 		kvmppc_mmu_pte_flush(vcpu, 0, 0);
264 		kvmppc_mmu_flush_segments(vcpu);
265 	}
266 
267 	if (mmu_has_feature(MMU_FTR_68_BIT_VA))
268 		vsid_bits = VSID_BITS_256M;
269 
270 	map->host_vsid = vsid_scramble(vcpu_book3s->proto_vsid_next++,
271 				       VSID_MULTIPLIER_256M, vsid_bits);
272 
273 	map->guest_vsid = gvsid;
274 	map->valid = true;
275 
276 	trace_kvm_book3s_slb_map(sid_map_mask, gvsid, map->host_vsid);
277 
278 	return map;
279 }
280 
281 static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
282 {
283 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
284 	int i;
285 	int max_slb_size = 64;
286 	int found_inval = -1;
287 	int r;
288 
289 	/* Are we overwriting? */
290 	for (i = 0; i < svcpu->slb_max; i++) {
291 		if (!(svcpu->slb[i].esid & SLB_ESID_V))
292 			found_inval = i;
293 		else if ((svcpu->slb[i].esid & ESID_MASK) == esid) {
294 			r = i;
295 			goto out;
296 		}
297 	}
298 
299 	/* Found a spare entry that was invalidated before */
300 	if (found_inval >= 0) {
301 		r = found_inval;
302 		goto out;
303 	}
304 
305 	/* No spare invalid entry, so create one */
306 
307 	if (mmu_slb_size < 64)
308 		max_slb_size = mmu_slb_size;
309 
310 	/* Overflowing -> purge */
311 	if ((svcpu->slb_max) == max_slb_size)
312 		kvmppc_mmu_flush_segments(vcpu);
313 
314 	r = svcpu->slb_max;
315 	svcpu->slb_max++;
316 
317 out:
318 	svcpu_put(svcpu);
319 	return r;
320 }
321 
322 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
323 {
324 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
325 	u64 esid = eaddr >> SID_SHIFT;
326 	u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;
327 	u64 slb_vsid = SLB_VSID_USER;
328 	u64 gvsid;
329 	int slb_index;
330 	struct kvmppc_sid_map *map;
331 	int r = 0;
332 
333 	slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);
334 
335 	if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
336 		/* Invalidate an entry */
337 		svcpu->slb[slb_index].esid = 0;
338 		r = -ENOENT;
339 		goto out;
340 	}
341 
342 	map = find_sid_vsid(vcpu, gvsid);
343 	if (!map)
344 		map = create_sid_map(vcpu, gvsid);
345 
346 	map->guest_esid = esid;
347 
348 	slb_vsid |= (map->host_vsid << 12);
349 	slb_vsid &= ~SLB_VSID_KP;
350 	slb_esid |= slb_index;
351 
352 #ifdef CONFIG_PPC_64K_PAGES
353 	/* Set host segment base page size to 64K if possible */
354 	if (gvsid & VSID_64K)
355 		slb_vsid |= mmu_psize_defs[MMU_PAGE_64K].sllp;
356 #endif
357 
358 	svcpu->slb[slb_index].esid = slb_esid;
359 	svcpu->slb[slb_index].vsid = slb_vsid;
360 
361 	trace_kvm_book3s_slbmte(slb_vsid, slb_esid);
362 
363 out:
364 	svcpu_put(svcpu);
365 	return r;
366 }
367 
368 void kvmppc_mmu_flush_segment(struct kvm_vcpu *vcpu, ulong ea, ulong seg_size)
369 {
370 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
371 	ulong seg_mask = -seg_size;
372 	int i;
373 
374 	for (i = 0; i < svcpu->slb_max; i++) {
375 		if ((svcpu->slb[i].esid & SLB_ESID_V) &&
376 		    (svcpu->slb[i].esid & seg_mask) == ea) {
377 			/* Invalidate this entry */
378 			svcpu->slb[i].esid = 0;
379 		}
380 	}
381 
382 	svcpu_put(svcpu);
383 }
384 
385 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
386 {
387 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
388 	svcpu->slb_max = 0;
389 	svcpu->slb[0].esid = 0;
390 	svcpu_put(svcpu);
391 }
392 
393 void kvmppc_mmu_destroy_pr(struct kvm_vcpu *vcpu)
394 {
395 	kvmppc_mmu_hpte_destroy(vcpu);
396 	__destroy_context(to_book3s(vcpu)->context_id[0]);
397 }
398 
399 int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
400 {
401 	struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
402 	int err;
403 
404 	err = hash__alloc_context_id();
405 	if (err < 0)
406 		return -1;
407 	vcpu3s->context_id[0] = err;
408 
409 	vcpu3s->proto_vsid_max = ((u64)(vcpu3s->context_id[0] + 1)
410 				  << ESID_BITS) - 1;
411 	vcpu3s->proto_vsid_first = (u64)vcpu3s->context_id[0] << ESID_BITS;
412 	vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
413 
414 	kvmppc_mmu_hpte_init(vcpu);
415 
416 	return 0;
417 }
418