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 	ppc_md.hpte_invalidate(pte->slot, pte->host_vpn,
38 			       pte->pagesize, pte->pagesize, MMU_SEGSIZE_256M,
39 			       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 	/*
149 	 * Use 64K pages if possible; otherwise, on 64K page kernels,
150 	 * we need to transfer 4 more bits from guest real to host real addr.
151 	 */
152 	if (vsid & VSID_64K)
153 		hpsize = MMU_PAGE_64K;
154 	else
155 		hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
156 
157 	hash = hpt_hash(vpn, mmu_psize_defs[hpsize].shift, MMU_SEGSIZE_256M);
158 
159 	cpte = kvmppc_mmu_hpte_cache_next(vcpu);
160 
161 	spin_lock(&kvm->mmu_lock);
162 	if (!cpte || mmu_notifier_retry(kvm, mmu_seq)) {
163 		r = -EAGAIN;
164 		goto out_unlock;
165 	}
166 
167 map_again:
168 	hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
169 
170 	/* In case we tried normal mapping already, let's nuke old entries */
171 	if (attempt > 1)
172 		if (ppc_md.hpte_remove(hpteg) < 0) {
173 			r = -1;
174 			goto out_unlock;
175 		}
176 
177 	ret = ppc_md.hpte_insert(hpteg, vpn, hpaddr, rflags, vflags,
178 				 hpsize, hpsize, MMU_SEGSIZE_256M);
179 
180 	if (ret < 0) {
181 		/* If we couldn't map a primary PTE, try a secondary */
182 		hash = ~hash;
183 		vflags ^= HPTE_V_SECONDARY;
184 		attempt++;
185 		goto map_again;
186 	} else {
187 		trace_kvm_book3s_64_mmu_map(rflags, hpteg,
188 					    vpn, hpaddr, orig_pte);
189 
190 		/* The ppc_md code may give us a secondary entry even though we
191 		   asked for a primary. Fix up. */
192 		if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
193 			hash = ~hash;
194 			hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
195 		}
196 
197 		cpte->slot = hpteg + (ret & 7);
198 		cpte->host_vpn = vpn;
199 		cpte->pte = *orig_pte;
200 		cpte->pfn = pfn;
201 		cpte->pagesize = hpsize;
202 
203 		kvmppc_mmu_hpte_cache_map(vcpu, cpte);
204 		cpte = NULL;
205 	}
206 
207 out_unlock:
208 	spin_unlock(&kvm->mmu_lock);
209 	kvm_release_pfn_clean(pfn);
210 	if (cpte)
211 		kvmppc_mmu_hpte_cache_free(cpte);
212 
213 out:
214 	return r;
215 }
216 
217 void kvmppc_mmu_unmap_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
218 {
219 	u64 mask = 0xfffffffffULL;
220 	u64 vsid;
221 
222 	vcpu->arch.mmu.esid_to_vsid(vcpu, pte->eaddr >> SID_SHIFT, &vsid);
223 	if (vsid & VSID_64K)
224 		mask = 0xffffffff0ULL;
225 	kvmppc_mmu_pte_vflush(vcpu, pte->vpage, mask);
226 }
227 
228 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
229 {
230 	struct kvmppc_sid_map *map;
231 	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
232 	u16 sid_map_mask;
233 	static int backwards_map = 0;
234 
235 	if (kvmppc_get_msr(vcpu) & MSR_PR)
236 		gvsid |= VSID_PR;
237 
238 	/* We might get collisions that trap in preceding order, so let's
239 	   map them differently */
240 
241 	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
242 	if (backwards_map)
243 		sid_map_mask = SID_MAP_MASK - sid_map_mask;
244 
245 	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
246 
247 	/* Make sure we're taking the other map next time */
248 	backwards_map = !backwards_map;
249 
250 	/* Uh-oh ... out of mappings. Let's flush! */
251 	if (vcpu_book3s->proto_vsid_next == vcpu_book3s->proto_vsid_max) {
252 		vcpu_book3s->proto_vsid_next = vcpu_book3s->proto_vsid_first;
253 		memset(vcpu_book3s->sid_map, 0,
254 		       sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
255 		kvmppc_mmu_pte_flush(vcpu, 0, 0);
256 		kvmppc_mmu_flush_segments(vcpu);
257 	}
258 	map->host_vsid = vsid_scramble(vcpu_book3s->proto_vsid_next++, 256M);
259 
260 	map->guest_vsid = gvsid;
261 	map->valid = true;
262 
263 	trace_kvm_book3s_slb_map(sid_map_mask, gvsid, map->host_vsid);
264 
265 	return map;
266 }
267 
268 static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
269 {
270 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
271 	int i;
272 	int max_slb_size = 64;
273 	int found_inval = -1;
274 	int r;
275 
276 	/* Are we overwriting? */
277 	for (i = 0; i < svcpu->slb_max; i++) {
278 		if (!(svcpu->slb[i].esid & SLB_ESID_V))
279 			found_inval = i;
280 		else if ((svcpu->slb[i].esid & ESID_MASK) == esid) {
281 			r = i;
282 			goto out;
283 		}
284 	}
285 
286 	/* Found a spare entry that was invalidated before */
287 	if (found_inval >= 0) {
288 		r = found_inval;
289 		goto out;
290 	}
291 
292 	/* No spare invalid entry, so create one */
293 
294 	if (mmu_slb_size < 64)
295 		max_slb_size = mmu_slb_size;
296 
297 	/* Overflowing -> purge */
298 	if ((svcpu->slb_max) == max_slb_size)
299 		kvmppc_mmu_flush_segments(vcpu);
300 
301 	r = svcpu->slb_max;
302 	svcpu->slb_max++;
303 
304 out:
305 	svcpu_put(svcpu);
306 	return r;
307 }
308 
309 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
310 {
311 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
312 	u64 esid = eaddr >> SID_SHIFT;
313 	u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;
314 	u64 slb_vsid = SLB_VSID_USER;
315 	u64 gvsid;
316 	int slb_index;
317 	struct kvmppc_sid_map *map;
318 	int r = 0;
319 
320 	slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);
321 
322 	if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
323 		/* Invalidate an entry */
324 		svcpu->slb[slb_index].esid = 0;
325 		r = -ENOENT;
326 		goto out;
327 	}
328 
329 	map = find_sid_vsid(vcpu, gvsid);
330 	if (!map)
331 		map = create_sid_map(vcpu, gvsid);
332 
333 	map->guest_esid = esid;
334 
335 	slb_vsid |= (map->host_vsid << 12);
336 	slb_vsid &= ~SLB_VSID_KP;
337 	slb_esid |= slb_index;
338 
339 #ifdef CONFIG_PPC_64K_PAGES
340 	/* Set host segment base page size to 64K if possible */
341 	if (gvsid & VSID_64K)
342 		slb_vsid |= mmu_psize_defs[MMU_PAGE_64K].sllp;
343 #endif
344 
345 	svcpu->slb[slb_index].esid = slb_esid;
346 	svcpu->slb[slb_index].vsid = slb_vsid;
347 
348 	trace_kvm_book3s_slbmte(slb_vsid, slb_esid);
349 
350 out:
351 	svcpu_put(svcpu);
352 	return r;
353 }
354 
355 void kvmppc_mmu_flush_segment(struct kvm_vcpu *vcpu, ulong ea, ulong seg_size)
356 {
357 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
358 	ulong seg_mask = -seg_size;
359 	int i;
360 
361 	for (i = 0; i < svcpu->slb_max; i++) {
362 		if ((svcpu->slb[i].esid & SLB_ESID_V) &&
363 		    (svcpu->slb[i].esid & seg_mask) == ea) {
364 			/* Invalidate this entry */
365 			svcpu->slb[i].esid = 0;
366 		}
367 	}
368 
369 	svcpu_put(svcpu);
370 }
371 
372 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
373 {
374 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
375 	svcpu->slb_max = 0;
376 	svcpu->slb[0].esid = 0;
377 	svcpu_put(svcpu);
378 }
379 
380 void kvmppc_mmu_destroy_pr(struct kvm_vcpu *vcpu)
381 {
382 	kvmppc_mmu_hpte_destroy(vcpu);
383 	__destroy_context(to_book3s(vcpu)->context_id[0]);
384 }
385 
386 int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
387 {
388 	struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
389 	int err;
390 
391 	err = __init_new_context();
392 	if (err < 0)
393 		return -1;
394 	vcpu3s->context_id[0] = err;
395 
396 	vcpu3s->proto_vsid_max = ((u64)(vcpu3s->context_id[0] + 1)
397 				  << ESID_BITS) - 1;
398 	vcpu3s->proto_vsid_first = (u64)vcpu3s->context_id[0] << ESID_BITS;
399 	vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
400 
401 	kvmppc_mmu_hpte_init(vcpu);
402 
403 	return 0;
404 }
405