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 (kvmppc_get_msr(vcpu) & 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 			bool iswrite)
143 {
144 	pfn_t hpaddr;
145 	u64 vpn;
146 	u64 vsid;
147 	struct kvmppc_sid_map *map;
148 	volatile u32 *pteg;
149 	u32 eaddr = orig_pte->eaddr;
150 	u32 pteg0, pteg1;
151 	register int rr = 0;
152 	bool primary = false;
153 	bool evict = false;
154 	struct hpte_cache *pte;
155 	int r = 0;
156 	bool writable;
157 
158 	/* Get host physical address for gpa */
159 	hpaddr = kvmppc_gfn_to_pfn(vcpu, orig_pte->raddr >> PAGE_SHIFT,
160 				   iswrite, &writable);
161 	if (is_error_noslot_pfn(hpaddr)) {
162 		printk(KERN_INFO "Couldn't get guest page for gfn %lx!\n",
163 				 orig_pte->eaddr);
164 		r = -EINVAL;
165 		goto out;
166 	}
167 	hpaddr <<= PAGE_SHIFT;
168 
169 	/* and write the mapping ea -> hpa into the pt */
170 	vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
171 	map = find_sid_vsid(vcpu, vsid);
172 	if (!map) {
173 		kvmppc_mmu_map_segment(vcpu, eaddr);
174 		map = find_sid_vsid(vcpu, vsid);
175 	}
176 	BUG_ON(!map);
177 
178 	vsid = map->host_vsid;
179 	vpn = (vsid << (SID_SHIFT - VPN_SHIFT)) |
180 		((eaddr & ~ESID_MASK) >> VPN_SHIFT);
181 next_pteg:
182 	if (rr == 16) {
183 		primary = !primary;
184 		evict = true;
185 		rr = 0;
186 	}
187 
188 	pteg = kvmppc_mmu_get_pteg(vcpu, vsid, eaddr, primary);
189 
190 	/* not evicting yet */
191 	if (!evict && (pteg[rr] & PTE_V)) {
192 		rr += 2;
193 		goto next_pteg;
194 	}
195 
196 	dprintk_mmu("KVM: old PTEG: %p (%d)\n", pteg, rr);
197 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[0], pteg[1]);
198 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[2], pteg[3]);
199 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[4], pteg[5]);
200 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[6], pteg[7]);
201 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[8], pteg[9]);
202 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[10], pteg[11]);
203 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[12], pteg[13]);
204 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[14], pteg[15]);
205 
206 	pteg0 = ((eaddr & 0x0fffffff) >> 22) | (vsid << 7) | PTE_V |
207 		(primary ? 0 : PTE_SEC);
208 	pteg1 = hpaddr | PTE_M | PTE_R | PTE_C;
209 
210 	if (orig_pte->may_write && writable) {
211 		pteg1 |= PP_RWRW;
212 		mark_page_dirty(vcpu->kvm, orig_pte->raddr >> PAGE_SHIFT);
213 	} else {
214 		pteg1 |= PP_RWRX;
215 	}
216 
217 	if (orig_pte->may_execute)
218 		kvmppc_mmu_flush_icache(hpaddr >> PAGE_SHIFT);
219 
220 	local_irq_disable();
221 
222 	if (pteg[rr]) {
223 		pteg[rr] = 0;
224 		asm volatile ("sync");
225 	}
226 	pteg[rr + 1] = pteg1;
227 	pteg[rr] = pteg0;
228 	asm volatile ("sync");
229 
230 	local_irq_enable();
231 
232 	dprintk_mmu("KVM: new PTEG: %p\n", pteg);
233 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[0], pteg[1]);
234 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[2], pteg[3]);
235 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[4], pteg[5]);
236 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[6], pteg[7]);
237 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[8], pteg[9]);
238 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[10], pteg[11]);
239 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[12], pteg[13]);
240 	dprintk_mmu("KVM:   %08x - %08x\n", pteg[14], pteg[15]);
241 
242 
243 	/* Now tell our Shadow PTE code about the new page */
244 
245 	pte = kvmppc_mmu_hpte_cache_next(vcpu);
246 	if (!pte) {
247 		kvm_release_pfn_clean(hpaddr >> PAGE_SHIFT);
248 		r = -EAGAIN;
249 		goto out;
250 	}
251 
252 	dprintk_mmu("KVM: %c%c Map 0x%llx: [%lx] 0x%llx (0x%llx) -> %lx\n",
253 		    orig_pte->may_write ? 'w' : '-',
254 		    orig_pte->may_execute ? 'x' : '-',
255 		    orig_pte->eaddr, (ulong)pteg, vpn,
256 		    orig_pte->vpage, hpaddr);
257 
258 	pte->slot = (ulong)&pteg[rr];
259 	pte->host_vpn = vpn;
260 	pte->pte = *orig_pte;
261 	pte->pfn = hpaddr >> PAGE_SHIFT;
262 
263 	kvmppc_mmu_hpte_cache_map(vcpu, pte);
264 
265 	kvm_release_pfn_clean(hpaddr >> PAGE_SHIFT);
266 out:
267 	return r;
268 }
269 
270 void kvmppc_mmu_unmap_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
271 {
272 	kvmppc_mmu_pte_vflush(vcpu, pte->vpage, 0xfffffffffULL);
273 }
274 
275 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
276 {
277 	struct kvmppc_sid_map *map;
278 	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
279 	u16 sid_map_mask;
280 	static int backwards_map = 0;
281 
282 	if (kvmppc_get_msr(vcpu) & MSR_PR)
283 		gvsid |= VSID_PR;
284 
285 	/* We might get collisions that trap in preceding order, so let's
286 	   map them differently */
287 
288 	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
289 	if (backwards_map)
290 		sid_map_mask = SID_MAP_MASK - sid_map_mask;
291 
292 	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
293 
294 	/* Make sure we're taking the other map next time */
295 	backwards_map = !backwards_map;
296 
297 	/* Uh-oh ... out of mappings. Let's flush! */
298 	if (vcpu_book3s->vsid_next >= VSID_POOL_SIZE) {
299 		vcpu_book3s->vsid_next = 0;
300 		memset(vcpu_book3s->sid_map, 0,
301 		       sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
302 		kvmppc_mmu_pte_flush(vcpu, 0, 0);
303 		kvmppc_mmu_flush_segments(vcpu);
304 	}
305 	map->host_vsid = vcpu_book3s->vsid_pool[vcpu_book3s->vsid_next];
306 	vcpu_book3s->vsid_next++;
307 
308 	map->guest_vsid = gvsid;
309 	map->valid = true;
310 
311 	return map;
312 }
313 
314 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
315 {
316 	u32 esid = eaddr >> SID_SHIFT;
317 	u64 gvsid;
318 	u32 sr;
319 	struct kvmppc_sid_map *map;
320 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
321 	int r = 0;
322 
323 	if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
324 		/* Invalidate an entry */
325 		svcpu->sr[esid] = SR_INVALID;
326 		r = -ENOENT;
327 		goto out;
328 	}
329 
330 	map = find_sid_vsid(vcpu, gvsid);
331 	if (!map)
332 		map = create_sid_map(vcpu, gvsid);
333 
334 	map->guest_esid = esid;
335 	sr = map->host_vsid | SR_KP;
336 	svcpu->sr[esid] = sr;
337 
338 	dprintk_sr("MMU: mtsr %d, 0x%x\n", esid, sr);
339 
340 out:
341 	svcpu_put(svcpu);
342 	return r;
343 }
344 
345 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
346 {
347 	int i;
348 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
349 
350 	dprintk_sr("MMU: flushing all segments (%d)\n", ARRAY_SIZE(svcpu->sr));
351 	for (i = 0; i < ARRAY_SIZE(svcpu->sr); i++)
352 		svcpu->sr[i] = SR_INVALID;
353 
354 	svcpu_put(svcpu);
355 }
356 
357 void kvmppc_mmu_destroy_pr(struct kvm_vcpu *vcpu)
358 {
359 	int i;
360 
361 	kvmppc_mmu_hpte_destroy(vcpu);
362 	preempt_disable();
363 	for (i = 0; i < SID_CONTEXTS; i++)
364 		__destroy_context(to_book3s(vcpu)->context_id[i]);
365 	preempt_enable();
366 }
367 
368 /* From mm/mmu_context_hash32.c */
369 #define CTX_TO_VSID(c, id)	((((c) * (897 * 16)) + (id * 0x111)) & 0xffffff)
370 
371 int kvmppc_mmu_init(struct kvm_vcpu *vcpu)
372 {
373 	struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
374 	int err;
375 	ulong sdr1;
376 	int i;
377 	int j;
378 
379 	for (i = 0; i < SID_CONTEXTS; i++) {
380 		err = __init_new_context();
381 		if (err < 0)
382 			goto init_fail;
383 		vcpu3s->context_id[i] = err;
384 
385 		/* Remember context id for this combination */
386 		for (j = 0; j < 16; j++)
387 			vcpu3s->vsid_pool[(i * 16) + j] = CTX_TO_VSID(err, j);
388 	}
389 
390 	vcpu3s->vsid_next = 0;
391 
392 	/* Remember where the HTAB is */
393 	asm ( "mfsdr1 %0" : "=r"(sdr1) );
394 	htabmask = ((sdr1 & 0x1FF) << 16) | 0xFFC0;
395 	htab = (ulong)__va(sdr1 & 0xffff0000);
396 
397 	kvmppc_mmu_hpte_init(vcpu);
398 
399 	return 0;
400 
401 init_fail:
402 	for (j = 0; j < i; j++) {
403 		if (!vcpu3s->context_id[j])
404 			continue;
405 
406 		__destroy_context(to_book3s(vcpu)->context_id[j]);
407 	}
408 
409 	return -1;
410 }
411