1 /*
2  * Copyright (C) 2010 SUSE Linux Products GmbH. All rights reserved.
3  *
4  * Authors:
5  *     Alexander Graf <agraf@suse.de>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License, version 2, as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
19  */
20 
21 #include <linux/kvm_host.h>
22 
23 #include <asm/kvm_ppc.h>
24 #include <asm/kvm_book3s.h>
25 #include <asm/mmu-hash32.h>
26 #include <asm/machdep.h>
27 #include <asm/mmu_context.h>
28 #include <asm/hw_irq.h>
29 
30 /* #define DEBUG_MMU */
31 /* #define DEBUG_SR */
32 
33 #ifdef DEBUG_MMU
34 #define dprintk_mmu(a, ...) printk(KERN_INFO a, __VA_ARGS__)
35 #else
36 #define dprintk_mmu(a, ...) do { } while(0)
37 #endif
38 
39 #ifdef DEBUG_SR
40 #define dprintk_sr(a, ...) printk(KERN_INFO a, __VA_ARGS__)
41 #else
42 #define dprintk_sr(a, ...) do { } while(0)
43 #endif
44 
45 #if PAGE_SHIFT != 12
46 #error Unknown page size
47 #endif
48 
49 #ifdef CONFIG_SMP
50 #error XXX need to grab mmu_hash_lock
51 #endif
52 
53 #ifdef CONFIG_PTE_64BIT
54 #error Only 32 bit pages are supported for now
55 #endif
56 
57 static ulong htab;
58 static u32 htabmask;
59 
60 void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
61 {
62 	volatile u32 *pteg;
63 
64 	/* Remove from host HTAB */
65 	pteg = (u32*)pte->slot;
66 	pteg[0] = 0;
67 
68 	/* And make sure it's gone from the TLB too */
69 	asm volatile ("sync");
70 	asm volatile ("tlbie %0" : : "r" (pte->pte.eaddr) : "memory");
71 	asm volatile ("sync");
72 	asm volatile ("tlbsync");
73 }
74 
75 /* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
76  * a hash, so we don't waste cycles on looping */
77 static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
78 {
79 	return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
80 		     ((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
81 		     ((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
82 		     ((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
83 		     ((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
84 		     ((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
85 		     ((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
86 		     ((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
87 }
88 
89 
90 static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
91 {
92 	struct kvmppc_sid_map *map;
93 	u16 sid_map_mask;
94 
95 	if (vcpu->arch.shared->msr & MSR_PR)
96 		gvsid |= VSID_PR;
97 
98 	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
99 	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
100 	if (map->guest_vsid == gvsid) {
101 		dprintk_sr("SR: Searching 0x%llx -> 0x%llx\n",
102 			    gvsid, map->host_vsid);
103 		return map;
104 	}
105 
106 	map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
107 	if (map->guest_vsid == gvsid) {
108 		dprintk_sr("SR: Searching 0x%llx -> 0x%llx\n",
109 			    gvsid, map->host_vsid);
110 		return map;
111 	}
112 
113 	dprintk_sr("SR: Searching 0x%llx -> not found\n", gvsid);
114 	return NULL;
115 }
116 
117 static u32 *kvmppc_mmu_get_pteg(struct kvm_vcpu *vcpu, u32 vsid, u32 eaddr,
118 				bool primary)
119 {
120 	u32 page, hash;
121 	ulong pteg = htab;
122 
123 	page = (eaddr & ~ESID_MASK) >> 12;
124 
125 	hash = ((vsid ^ page) << 6);
126 	if (!primary)
127 		hash = ~hash;
128 
129 	hash &= htabmask;
130 
131 	pteg |= hash;
132 
133 	dprintk_mmu("htab: %lx | hash: %x | htabmask: %x | pteg: %lx\n",
134 		htab, hash, htabmask, pteg);
135 
136 	return (u32*)pteg;
137 }
138 
139 extern char etext[];
140 
141 int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte)
142 {
143 	pfn_t hpaddr;
144 	u64 va;
145 	u64 vsid;
146 	struct kvmppc_sid_map *map;
147 	volatile u32 *pteg;
148 	u32 eaddr = orig_pte->eaddr;
149 	u32 pteg0, pteg1;
150 	register int rr = 0;
151 	bool primary = false;
152 	bool evict = false;
153 	struct hpte_cache *pte;
154 	int r = 0;
155 
156 	/* Get host physical address for gpa */
157 	hpaddr = kvmppc_gfn_to_pfn(vcpu, orig_pte->raddr >> PAGE_SHIFT);
158 	if (is_error_pfn(hpaddr)) {
159 		printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n",
160 				 orig_pte->eaddr);
161 		r = -EINVAL;
162 		goto out;
163 	}
164 	hpaddr <<= PAGE_SHIFT;
165 
166 	/* and write the mapping ea -> hpa into the pt */
167 	vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
168 	map = find_sid_vsid(vcpu, vsid);
169 	if (!map) {
170 		kvmppc_mmu_map_segment(vcpu, eaddr);
171 		map = find_sid_vsid(vcpu, vsid);
172 	}
173 	BUG_ON(!map);
174 
175 	vsid = map->host_vsid;
176 	va = (vsid << SID_SHIFT) | (eaddr & ~ESID_MASK);
177 
178 next_pteg:
179 	if (rr == 16) {
180 		primary = !primary;
181 		evict = true;
182 		rr = 0;
183 	}
184 
185 	pteg = kvmppc_mmu_get_pteg(vcpu, vsid, eaddr, primary);
186 
187 	/* not evicting yet */
188 	if (!evict && (pteg[rr] & PTE_V)) {
189 		rr += 2;
190 		goto next_pteg;
191 	}
192 
193 	dprintk_mmu("KVM: old PTEG: %p (%d)\n", pteg, rr);
194 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[0], pteg[1]);
195 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[2], pteg[3]);
196 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[4], pteg[5]);
197 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[6], pteg[7]);
198 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[8], pteg[9]);
199 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[10], pteg[11]);
200 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[12], pteg[13]);
201 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[14], pteg[15]);
202 
203 	pteg0 = ((eaddr & 0x0fffffff) >> 22) | (vsid << 7) | PTE_V |
204 		(primary ? 0 : PTE_SEC);
205 	pteg1 = hpaddr | PTE_M | PTE_R | PTE_C;
206 
207 	if (orig_pte->may_write) {
208 		pteg1 |= PP_RWRW;
209 		mark_page_dirty(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
210 	} else {
211 		pteg1 |= PP_RWRX;
212 	}
213 
214 	local_irq_disable();
215 
216 	if (pteg[rr]) {
217 		pteg[rr] = 0;
218 		asm volatile ("sync");
219 	}
220 	pteg[rr + 1] = pteg1;
221 	pteg[rr] = pteg0;
222 	asm volatile ("sync");
223 
224 	local_irq_enable();
225 
226 	dprintk_mmu("KVM: new PTEG: %p\n", pteg);
227 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[0], pteg[1]);
228 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[2], pteg[3]);
229 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[4], pteg[5]);
230 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[6], pteg[7]);
231 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[8], pteg[9]);
232 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[10], pteg[11]);
233 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[12], pteg[13]);
234 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[14], pteg[15]);
235 
236 
237 	/* Now tell our Shadow PTE code about the new page */
238 
239 	pte = kvmppc_mmu_hpte_cache_next(vcpu);
240 
241 	dprintk_mmu("KVM: %c%c Map 0x%llx: [%lx] 0x%llx (0x%llx) -> %lx\n",
242 		    orig_pte->may_write ? 'w' : '-',
243 		    orig_pte->may_execute ? 'x' : '-',
244 		    orig_pte->eaddr, (ulong)pteg, va,
245 		    orig_pte->vpage, hpaddr);
246 
247 	pte->slot = (ulong)&pteg[rr];
248 	pte->host_va = va;
249 	pte->pte = *orig_pte;
250 	pte->pfn = hpaddr >> PAGE_SHIFT;
251 
252 	kvmppc_mmu_hpte_cache_map(vcpu, pte);
253 
254 out:
255 	return r;
256 }
257 
258 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
259 {
260 	struct kvmppc_sid_map *map;
261 	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
262 	u16 sid_map_mask;
263 	static int backwards_map = 0;
264 
265 	if (vcpu->arch.shared->msr & MSR_PR)
266 		gvsid |= VSID_PR;
267 
268 	/* We might get collisions that trap in preceding order, so let's
269 	   map them differently */
270 
271 	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
272 	if (backwards_map)
273 		sid_map_mask = SID_MAP_MASK - sid_map_mask;
274 
275 	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
276 
277 	/* Make sure we're taking the other map next time */
278 	backwards_map = !backwards_map;
279 
280 	/* Uh-oh ... out of mappings. Let's flush! */
281 	if (vcpu_book3s->vsid_next >= VSID_POOL_SIZE) {
282 		vcpu_book3s->vsid_next = 0;
283 		memset(vcpu_book3s->sid_map, 0,
284 		       sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
285 		kvmppc_mmu_pte_flush(vcpu, 0, 0);
286 		kvmppc_mmu_flush_segments(vcpu);
287 	}
288 	map->host_vsid = vcpu_book3s->vsid_pool[vcpu_book3s->vsid_next];
289 	vcpu_book3s->vsid_next++;
290 
291 	map->guest_vsid = gvsid;
292 	map->valid = true;
293 
294 	return map;
295 }
296 
297 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
298 {
299 	u32 esid = eaddr >> SID_SHIFT;
300 	u64 gvsid;
301 	u32 sr;
302 	struct kvmppc_sid_map *map;
303 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
304 	int r = 0;
305 
306 	if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
307 		/* Invalidate an entry */
308 		svcpu->sr[esid] = SR_INVALID;
309 		r = -ENOENT;
310 		goto out;
311 	}
312 
313 	map = find_sid_vsid(vcpu, gvsid);
314 	if (!map)
315 		map = create_sid_map(vcpu, gvsid);
316 
317 	map->guest_esid = esid;
318 	sr = map->host_vsid | SR_KP;
319 	svcpu->sr[esid] = sr;
320 
321 	dprintk_sr("MMU: mtsr %d, 0x%x\n", esid, sr);
322 
323 out:
324 	svcpu_put(svcpu);
325 	return r;
326 }
327 
328 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
329 {
330 	int i;
331 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
332 
333 	dprintk_sr("MMU: flushing all segments (%d)\n", ARRAY_SIZE(svcpu->sr));
334 	for (i = 0; i < ARRAY_SIZE(svcpu->sr); i++)
335 		svcpu->sr[i] = SR_INVALID;
336 
337 	svcpu_put(svcpu);
338 }
339 
340 void kvmppc_mmu_destroy(struct kvm_vcpu *vcpu)
341 {
342 	int i;
343 
344 	kvmppc_mmu_hpte_destroy(vcpu);
345 	preempt_disable();
346 	for (i = 0; i < SID_CONTEXTS; i++)
347 		__destroy_context(to_book3s(vcpu)->context_id[i]);
348 	preempt_enable();
349 }
350 
351 /* From mm/mmu_context_hash32.c */
352 #define CTX_TO_VSID(c, id)	((((c) * (897 * 16)) + (id * 0x111)) & 0xffffff)
353 
354 int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
355 {
356 	struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
357 	int err;
358 	ulong sdr1;
359 	int i;
360 	int j;
361 
362 	for (i = 0; i < SID_CONTEXTS; i++) {
363 		err = __init_new_context();
364 		if (err < 0)
365 			goto init_fail;
366 		vcpu3s->context_id[i] = err;
367 
368 		/* Remember context id for this combination */
369 		for (j = 0; j < 16; j++)
370 			vcpu3s->vsid_pool[(i * 16) + j] = CTX_TO_VSID(err, j);
371 	}
372 
373 	vcpu3s->vsid_next = 0;
374 
375 	/* Remember where the HTAB is */
376 	asm ( "mfsdr1 %0" : "=r"(sdr1) );
377 	htabmask = ((sdr1 & 0x1FF) << 16) | 0xFFC0;
378 	htab = (ulong)__va(sdr1 & 0xffff0000);
379 
380 	kvmppc_mmu_hpte_init(vcpu);
381 
382 	return 0;
383 
384 init_fail:
385 	for (j = 0; j < i; j++) {
386 		if (!vcpu3s->context_id[j])
387 			continue;
388 
389 		__destroy_context(to_book3s(vcpu)->context_id[j]);
390 	}
391 
392 	return -1;
393 }
394