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/mmu-hash64.h>
27 #include <asm/machdep.h>
28 #include <asm/mmu_context.h>
29 #include <asm/hw_irq.h>
30 
31 #define PTE_SIZE 12
32 #define VSID_ALL 0
33 
34 /* #define DEBUG_MMU */
35 /* #define DEBUG_SLB */
36 
37 #ifdef DEBUG_MMU
38 #define dprintk_mmu(a, ...) printk(KERN_INFO a, __VA_ARGS__)
39 #else
40 #define dprintk_mmu(a, ...) do { } while(0)
41 #endif
42 
43 #ifdef DEBUG_SLB
44 #define dprintk_slb(a, ...) printk(KERN_INFO a, __VA_ARGS__)
45 #else
46 #define dprintk_slb(a, ...) do { } while(0)
47 #endif
48 
49 static void invalidate_pte(struct hpte_cache *pte)
50 {
51 	dprintk_mmu("KVM: Flushing SPT %d: 0x%llx (0x%llx) -> 0x%llx\n",
52 		    i, pte->pte.eaddr, pte->pte.vpage, pte->host_va);
53 
54 	ppc_md.hpte_invalidate(pte->slot, pte->host_va,
55 			       MMU_PAGE_4K, MMU_SEGSIZE_256M,
56 			       false);
57 	pte->host_va = 0;
58 	kvm_release_pfn_dirty(pte->pfn);
59 }
60 
61 void kvmppc_mmu_pte_flush(struct kvm_vcpu *vcpu, u64 guest_ea, u64 ea_mask)
62 {
63 	int i;
64 
65 	dprintk_mmu("KVM: Flushing %d Shadow PTEs: 0x%llx & 0x%llx\n",
66 		    vcpu->arch.hpte_cache_offset, guest_ea, ea_mask);
67 	BUG_ON(vcpu->arch.hpte_cache_offset > HPTEG_CACHE_NUM);
68 
69 	guest_ea &= ea_mask;
70 	for (i = 0; i < vcpu->arch.hpte_cache_offset; i++) {
71 		struct hpte_cache *pte;
72 
73 		pte = &vcpu->arch.hpte_cache[i];
74 		if (!pte->host_va)
75 			continue;
76 
77 		if ((pte->pte.eaddr & ea_mask) == guest_ea) {
78 			invalidate_pte(pte);
79 		}
80 	}
81 
82 	/* Doing a complete flush -> start from scratch */
83 	if (!ea_mask)
84 		vcpu->arch.hpte_cache_offset = 0;
85 }
86 
87 void kvmppc_mmu_pte_vflush(struct kvm_vcpu *vcpu, u64 guest_vp, u64 vp_mask)
88 {
89 	int i;
90 
91 	dprintk_mmu("KVM: Flushing %d Shadow vPTEs: 0x%llx & 0x%llx\n",
92 		    vcpu->arch.hpte_cache_offset, guest_vp, vp_mask);
93 	BUG_ON(vcpu->arch.hpte_cache_offset > HPTEG_CACHE_NUM);
94 
95 	guest_vp &= vp_mask;
96 	for (i = 0; i < vcpu->arch.hpte_cache_offset; i++) {
97 		struct hpte_cache *pte;
98 
99 		pte = &vcpu->arch.hpte_cache[i];
100 		if (!pte->host_va)
101 			continue;
102 
103 		if ((pte->pte.vpage & vp_mask) == guest_vp) {
104 			invalidate_pte(pte);
105 		}
106 	}
107 }
108 
109 void kvmppc_mmu_pte_pflush(struct kvm_vcpu *vcpu, u64 pa_start, u64 pa_end)
110 {
111 	int i;
112 
113 	dprintk_mmu("KVM: Flushing %d Shadow pPTEs: 0x%llx & 0x%llx\n",
114 		    vcpu->arch.hpte_cache_offset, guest_pa, pa_mask);
115 	BUG_ON(vcpu->arch.hpte_cache_offset > HPTEG_CACHE_NUM);
116 
117 	for (i = 0; i < vcpu->arch.hpte_cache_offset; i++) {
118 		struct hpte_cache *pte;
119 
120 		pte = &vcpu->arch.hpte_cache[i];
121 		if (!pte->host_va)
122 			continue;
123 
124 		if ((pte->pte.raddr >= pa_start) &&
125 		    (pte->pte.raddr < pa_end)) {
126 			invalidate_pte(pte);
127 		}
128 	}
129 }
130 
131 struct kvmppc_pte *kvmppc_mmu_find_pte(struct kvm_vcpu *vcpu, u64 ea, bool data)
132 {
133 	int i;
134 	u64 guest_vp;
135 
136 	guest_vp = vcpu->arch.mmu.ea_to_vp(vcpu, ea, false);
137 	for (i=0; i<vcpu->arch.hpte_cache_offset; i++) {
138 		struct hpte_cache *pte;
139 
140 		pte = &vcpu->arch.hpte_cache[i];
141 		if (!pte->host_va)
142 			continue;
143 
144 		if (pte->pte.vpage == guest_vp)
145 			return &pte->pte;
146 	}
147 
148 	return NULL;
149 }
150 
151 static int kvmppc_mmu_hpte_cache_next(struct kvm_vcpu *vcpu)
152 {
153 	if (vcpu->arch.hpte_cache_offset == HPTEG_CACHE_NUM)
154 		kvmppc_mmu_pte_flush(vcpu, 0, 0);
155 
156 	return vcpu->arch.hpte_cache_offset++;
157 }
158 
159 /* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
160  * a hash, so we don't waste cycles on looping */
161 static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
162 {
163 	return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
164 		     ((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
165 		     ((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
166 		     ((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
167 		     ((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
168 		     ((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
169 		     ((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
170 		     ((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
171 }
172 
173 
174 static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
175 {
176 	struct kvmppc_sid_map *map;
177 	u16 sid_map_mask;
178 
179 	if (vcpu->arch.msr & MSR_PR)
180 		gvsid |= VSID_PR;
181 
182 	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
183 	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
184 	if (map->guest_vsid == gvsid) {
185 		dprintk_slb("SLB: Searching 0x%llx -> 0x%llx\n",
186 			    gvsid, map->host_vsid);
187 		return map;
188 	}
189 
190 	map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
191 	if (map->guest_vsid == gvsid) {
192 		dprintk_slb("SLB: Searching 0x%llx -> 0x%llx\n",
193 			    gvsid, map->host_vsid);
194 		return map;
195 	}
196 
197 	dprintk_slb("SLB: Searching 0x%llx -> not found\n", gvsid);
198 	return NULL;
199 }
200 
201 int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte)
202 {
203 	pfn_t hpaddr;
204 	ulong hash, hpteg, va;
205 	u64 vsid;
206 	int ret;
207 	int rflags = 0x192;
208 	int vflags = 0;
209 	int attempt = 0;
210 	struct kvmppc_sid_map *map;
211 
212 	/* Get host physical address for gpa */
213 	hpaddr = gfn_to_pfn(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
214 	if (kvm_is_error_hva(hpaddr)) {
215 		printk(KERN_INFO "Couldn't get guest page for gfn %llx!\n", orig_pte->eaddr);
216 		return -EINVAL;
217 	}
218 	hpaddr <<= PAGE_SHIFT;
219 #if PAGE_SHIFT == 12
220 #elif PAGE_SHIFT == 16
221 	hpaddr |= orig_pte->raddr & 0xf000;
222 #else
223 #error Unknown page size
224 #endif
225 
226 	/* and write the mapping ea -> hpa into the pt */
227 	vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
228 	map = find_sid_vsid(vcpu, vsid);
229 	if (!map) {
230 		kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
231 		map = find_sid_vsid(vcpu, vsid);
232 	}
233 	BUG_ON(!map);
234 
235 	vsid = map->host_vsid;
236 	va = hpt_va(orig_pte->eaddr, vsid, MMU_SEGSIZE_256M);
237 
238 	if (!orig_pte->may_write)
239 		rflags |= HPTE_R_PP;
240 	else
241 		mark_page_dirty(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
242 
243 	if (!orig_pte->may_execute)
244 		rflags |= HPTE_R_N;
245 
246 	hash = hpt_hash(va, PTE_SIZE, MMU_SEGSIZE_256M);
247 
248 map_again:
249 	hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
250 
251 	/* In case we tried normal mapping already, let's nuke old entries */
252 	if (attempt > 1)
253 		if (ppc_md.hpte_remove(hpteg) < 0)
254 			return -1;
255 
256 	ret = ppc_md.hpte_insert(hpteg, va, hpaddr, rflags, vflags, MMU_PAGE_4K, MMU_SEGSIZE_256M);
257 
258 	if (ret < 0) {
259 		/* If we couldn't map a primary PTE, try a secondary */
260 #ifdef USE_SECONDARY
261 		hash = ~hash;
262 		attempt++;
263 		if (attempt % 2)
264 			vflags = HPTE_V_SECONDARY;
265 		else
266 			vflags = 0;
267 #else
268 		attempt = 2;
269 #endif
270 		goto map_again;
271 	} else {
272 		int hpte_id = kvmppc_mmu_hpte_cache_next(vcpu);
273 		struct hpte_cache *pte = &vcpu->arch.hpte_cache[hpte_id];
274 
275 		dprintk_mmu("KVM: %c%c Map 0x%llx: [%lx] 0x%lx (0x%llx) -> %lx\n",
276 			    ((rflags & HPTE_R_PP) == 3) ? '-' : 'w',
277 			    (rflags & HPTE_R_N) ? '-' : 'x',
278 			    orig_pte->eaddr, hpteg, va, orig_pte->vpage, hpaddr);
279 
280 		pte->slot = hpteg + (ret & 7);
281 		pte->host_va = va;
282 		pte->pte = *orig_pte;
283 		pte->pfn = hpaddr >> PAGE_SHIFT;
284 	}
285 
286 	return 0;
287 }
288 
289 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
290 {
291 	struct kvmppc_sid_map *map;
292 	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
293 	u16 sid_map_mask;
294 	static int backwards_map = 0;
295 
296 	if (vcpu->arch.msr & MSR_PR)
297 		gvsid |= VSID_PR;
298 
299 	/* We might get collisions that trap in preceding order, so let's
300 	   map them differently */
301 
302 	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
303 	if (backwards_map)
304 		sid_map_mask = SID_MAP_MASK - sid_map_mask;
305 
306 	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
307 
308 	/* Make sure we're taking the other map next time */
309 	backwards_map = !backwards_map;
310 
311 	/* Uh-oh ... out of mappings. Let's flush! */
312 	if (vcpu_book3s->vsid_next == vcpu_book3s->vsid_max) {
313 		vcpu_book3s->vsid_next = vcpu_book3s->vsid_first;
314 		memset(vcpu_book3s->sid_map, 0,
315 		       sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
316 		kvmppc_mmu_pte_flush(vcpu, 0, 0);
317 		kvmppc_mmu_flush_segments(vcpu);
318 	}
319 	map->host_vsid = vcpu_book3s->vsid_next++;
320 
321 	map->guest_vsid = gvsid;
322 	map->valid = true;
323 
324 	return map;
325 }
326 
327 static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
328 {
329 	int i;
330 	int max_slb_size = 64;
331 	int found_inval = -1;
332 	int r;
333 
334 	if (!get_paca()->kvm_slb_max)
335 		get_paca()->kvm_slb_max = 1;
336 
337 	/* Are we overwriting? */
338 	for (i = 1; i < get_paca()->kvm_slb_max; i++) {
339 		if (!(get_paca()->kvm_slb[i].esid & SLB_ESID_V))
340 			found_inval = i;
341 		else if ((get_paca()->kvm_slb[i].esid & ESID_MASK) == esid)
342 			return i;
343 	}
344 
345 	/* Found a spare entry that was invalidated before */
346 	if (found_inval > 0)
347 		return found_inval;
348 
349 	/* No spare invalid entry, so create one */
350 
351 	if (mmu_slb_size < 64)
352 		max_slb_size = mmu_slb_size;
353 
354 	/* Overflowing -> purge */
355 	if ((get_paca()->kvm_slb_max) == max_slb_size)
356 		kvmppc_mmu_flush_segments(vcpu);
357 
358 	r = get_paca()->kvm_slb_max;
359 	get_paca()->kvm_slb_max++;
360 
361 	return r;
362 }
363 
364 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
365 {
366 	u64 esid = eaddr >> SID_SHIFT;
367 	u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;
368 	u64 slb_vsid = SLB_VSID_USER;
369 	u64 gvsid;
370 	int slb_index;
371 	struct kvmppc_sid_map *map;
372 
373 	slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);
374 
375 	if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
376 		/* Invalidate an entry */
377 		get_paca()->kvm_slb[slb_index].esid = 0;
378 		return -ENOENT;
379 	}
380 
381 	map = find_sid_vsid(vcpu, gvsid);
382 	if (!map)
383 		map = create_sid_map(vcpu, gvsid);
384 
385 	map->guest_esid = esid;
386 
387 	slb_vsid |= (map->host_vsid << 12);
388 	slb_vsid &= ~SLB_VSID_KP;
389 	slb_esid |= slb_index;
390 
391 	get_paca()->kvm_slb[slb_index].esid = slb_esid;
392 	get_paca()->kvm_slb[slb_index].vsid = slb_vsid;
393 
394 	dprintk_slb("slbmte %#llx, %#llx\n", slb_vsid, slb_esid);
395 
396 	return 0;
397 }
398 
399 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
400 {
401 	get_paca()->kvm_slb_max = 1;
402 	get_paca()->kvm_slb[0].esid = 0;
403 }
404 
405 void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
406 {
407 	kvmppc_mmu_pte_flush(vcpu, 0, 0);
408 }
409