1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2009 SUSE Linux Products GmbH. All rights reserved.
4  *
5  * Authors:
6  *     Alexander Graf <agraf@suse.de>
7  *     Kevin Wolf <mail@kevin-wolf.de>
8  */
9 
10 #include <linux/kvm_host.h>
11 #include <linux/pkeys.h>
12 
13 #include <asm/kvm_ppc.h>
14 #include <asm/kvm_book3s.h>
15 #include <asm/book3s/64/mmu-hash.h>
16 #include <asm/machdep.h>
17 #include <asm/mmu_context.h>
18 #include <asm/hw_irq.h>
19 #include "trace_pr.h"
20 #include "book3s.h"
21 
22 #define PTE_SIZE 12
23 
kvmppc_mmu_invalidate_pte(struct kvm_vcpu * vcpu,struct hpte_cache * pte)24 void kvmppc_mmu_invalidate_pte(struct kvm_vcpu *vcpu, struct hpte_cache *pte)
25 {
26 	mmu_hash_ops.hpte_invalidate(pte->slot, pte->host_vpn,
27 				     pte->pagesize, pte->pagesize,
28 				     MMU_SEGSIZE_256M, false);
29 }
30 
31 /* We keep 512 gvsid->hvsid entries, mapping the guest ones to the array using
32  * a hash, so we don't waste cycles on looping */
kvmppc_sid_hash(struct kvm_vcpu * vcpu,u64 gvsid)33 static u16 kvmppc_sid_hash(struct kvm_vcpu *vcpu, u64 gvsid)
34 {
35 	return (u16)(((gvsid >> (SID_MAP_BITS * 7)) & SID_MAP_MASK) ^
36 		     ((gvsid >> (SID_MAP_BITS * 6)) & SID_MAP_MASK) ^
37 		     ((gvsid >> (SID_MAP_BITS * 5)) & SID_MAP_MASK) ^
38 		     ((gvsid >> (SID_MAP_BITS * 4)) & SID_MAP_MASK) ^
39 		     ((gvsid >> (SID_MAP_BITS * 3)) & SID_MAP_MASK) ^
40 		     ((gvsid >> (SID_MAP_BITS * 2)) & SID_MAP_MASK) ^
41 		     ((gvsid >> (SID_MAP_BITS * 1)) & SID_MAP_MASK) ^
42 		     ((gvsid >> (SID_MAP_BITS * 0)) & SID_MAP_MASK));
43 }
44 
45 
find_sid_vsid(struct kvm_vcpu * vcpu,u64 gvsid)46 static struct kvmppc_sid_map *find_sid_vsid(struct kvm_vcpu *vcpu, u64 gvsid)
47 {
48 	struct kvmppc_sid_map *map;
49 	u16 sid_map_mask;
50 
51 	if (kvmppc_get_msr(vcpu) & MSR_PR)
52 		gvsid |= VSID_PR;
53 
54 	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
55 	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
56 	if (map->valid && (map->guest_vsid == gvsid)) {
57 		trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
58 		return map;
59 	}
60 
61 	map = &to_book3s(vcpu)->sid_map[SID_MAP_MASK - sid_map_mask];
62 	if (map->valid && (map->guest_vsid == gvsid)) {
63 		trace_kvm_book3s_slb_found(gvsid, map->host_vsid);
64 		return map;
65 	}
66 
67 	trace_kvm_book3s_slb_fail(sid_map_mask, gvsid);
68 	return NULL;
69 }
70 
kvmppc_mmu_map_page(struct kvm_vcpu * vcpu,struct kvmppc_pte * orig_pte,bool iswrite)71 int kvmppc_mmu_map_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *orig_pte,
72 			bool iswrite)
73 {
74 	unsigned long vpn;
75 	kvm_pfn_t hpaddr;
76 	ulong hash, hpteg;
77 	u64 vsid;
78 	int ret;
79 	int rflags = 0x192;
80 	int vflags = 0;
81 	int attempt = 0;
82 	struct kvmppc_sid_map *map;
83 	int r = 0;
84 	int hpsize = MMU_PAGE_4K;
85 	bool writable;
86 	unsigned long mmu_seq;
87 	struct kvm *kvm = vcpu->kvm;
88 	struct hpte_cache *cpte;
89 	unsigned long gfn = orig_pte->raddr >> PAGE_SHIFT;
90 	unsigned long pfn;
91 
92 	/* used to check for invalidations in progress */
93 	mmu_seq = kvm->mmu_invalidate_seq;
94 	smp_rmb();
95 
96 	/* Get host physical address for gpa */
97 	pfn = kvmppc_gpa_to_pfn(vcpu, orig_pte->raddr, iswrite, &writable);
98 	if (is_error_noslot_pfn(pfn)) {
99 		printk(KERN_INFO "Couldn't get guest page for gpa %lx!\n",
100 		       orig_pte->raddr);
101 		r = -EINVAL;
102 		goto out;
103 	}
104 	hpaddr = pfn << PAGE_SHIFT;
105 
106 	/* and write the mapping ea -> hpa into the pt */
107 	vcpu->arch.mmu.esid_to_vsid(vcpu, orig_pte->eaddr >> SID_SHIFT, &vsid);
108 	map = find_sid_vsid(vcpu, vsid);
109 	if (!map) {
110 		ret = kvmppc_mmu_map_segment(vcpu, orig_pte->eaddr);
111 		WARN_ON(ret < 0);
112 		map = find_sid_vsid(vcpu, vsid);
113 	}
114 	if (!map) {
115 		printk(KERN_ERR "KVM: Segment map for 0x%llx (0x%lx) failed\n",
116 				vsid, orig_pte->eaddr);
117 		WARN_ON(true);
118 		r = -EINVAL;
119 		goto out;
120 	}
121 
122 	vpn = hpt_vpn(orig_pte->eaddr, map->host_vsid, MMU_SEGSIZE_256M);
123 
124 	kvm_set_pfn_accessed(pfn);
125 	if (!orig_pte->may_write || !writable)
126 		rflags |= PP_RXRX;
127 	else {
128 		mark_page_dirty(vcpu->kvm, gfn);
129 		kvm_set_pfn_dirty(pfn);
130 	}
131 
132 	if (!orig_pte->may_execute)
133 		rflags |= HPTE_R_N;
134 	else
135 		kvmppc_mmu_flush_icache(pfn);
136 
137 	rflags |= pte_to_hpte_pkey_bits(0, HPTE_USE_KERNEL_KEY);
138 	rflags = (rflags & ~HPTE_R_WIMG) | orig_pte->wimg;
139 
140 	/*
141 	 * Use 64K pages if possible; otherwise, on 64K page kernels,
142 	 * we need to transfer 4 more bits from guest real to host real addr.
143 	 */
144 	if (vsid & VSID_64K)
145 		hpsize = MMU_PAGE_64K;
146 	else
147 		hpaddr |= orig_pte->raddr & (~0xfffULL & ~PAGE_MASK);
148 
149 	hash = hpt_hash(vpn, mmu_psize_defs[hpsize].shift, MMU_SEGSIZE_256M);
150 
151 	cpte = kvmppc_mmu_hpte_cache_next(vcpu);
152 
153 	spin_lock(&kvm->mmu_lock);
154 	if (!cpte || mmu_invalidate_retry(kvm, mmu_seq)) {
155 		r = -EAGAIN;
156 		goto out_unlock;
157 	}
158 
159 map_again:
160 	hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
161 
162 	/* In case we tried normal mapping already, let's nuke old entries */
163 	if (attempt > 1)
164 		if (mmu_hash_ops.hpte_remove(hpteg) < 0) {
165 			r = -1;
166 			goto out_unlock;
167 		}
168 
169 	ret = mmu_hash_ops.hpte_insert(hpteg, vpn, hpaddr, rflags, vflags,
170 				       hpsize, hpsize, MMU_SEGSIZE_256M);
171 
172 	if (ret == -1) {
173 		/* If we couldn't map a primary PTE, try a secondary */
174 		hash = ~hash;
175 		vflags ^= HPTE_V_SECONDARY;
176 		attempt++;
177 		goto map_again;
178 	} else if (ret < 0) {
179 		r = -EIO;
180 		goto out_unlock;
181 	} else {
182 		trace_kvm_book3s_64_mmu_map(rflags, hpteg,
183 					    vpn, hpaddr, orig_pte);
184 
185 		/*
186 		 * The mmu_hash_ops code may give us a secondary entry even
187 		 * though we asked for a primary. Fix up.
188 		 */
189 		if ((ret & _PTEIDX_SECONDARY) && !(vflags & HPTE_V_SECONDARY)) {
190 			hash = ~hash;
191 			hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
192 		}
193 
194 		cpte->slot = hpteg + (ret & 7);
195 		cpte->host_vpn = vpn;
196 		cpte->pte = *orig_pte;
197 		cpte->pfn = pfn;
198 		cpte->pagesize = hpsize;
199 
200 		kvmppc_mmu_hpte_cache_map(vcpu, cpte);
201 		cpte = NULL;
202 	}
203 
204 out_unlock:
205 	spin_unlock(&kvm->mmu_lock);
206 	kvm_release_pfn_clean(pfn);
207 	if (cpte)
208 		kvmppc_mmu_hpte_cache_free(cpte);
209 
210 out:
211 	return r;
212 }
213 
kvmppc_mmu_unmap_page(struct kvm_vcpu * vcpu,struct kvmppc_pte * pte)214 void kvmppc_mmu_unmap_page(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
215 {
216 	u64 mask = 0xfffffffffULL;
217 	u64 vsid;
218 
219 	vcpu->arch.mmu.esid_to_vsid(vcpu, pte->eaddr >> SID_SHIFT, &vsid);
220 	if (vsid & VSID_64K)
221 		mask = 0xffffffff0ULL;
222 	kvmppc_mmu_pte_vflush(vcpu, pte->vpage, mask);
223 }
224 
create_sid_map(struct kvm_vcpu * vcpu,u64 gvsid)225 static struct kvmppc_sid_map *create_sid_map(struct kvm_vcpu *vcpu, u64 gvsid)
226 {
227 	unsigned long vsid_bits = VSID_BITS_65_256M;
228 	struct kvmppc_sid_map *map;
229 	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
230 	u16 sid_map_mask;
231 	static int backwards_map;
232 
233 	if (kvmppc_get_msr(vcpu) & MSR_PR)
234 		gvsid |= VSID_PR;
235 
236 	/* We might get collisions that trap in preceding order, so let's
237 	   map them differently */
238 
239 	sid_map_mask = kvmppc_sid_hash(vcpu, gvsid);
240 	if (backwards_map)
241 		sid_map_mask = SID_MAP_MASK - sid_map_mask;
242 
243 	map = &to_book3s(vcpu)->sid_map[sid_map_mask];
244 
245 	/* Make sure we're taking the other map next time */
246 	backwards_map = !backwards_map;
247 
248 	/* Uh-oh ... out of mappings. Let's flush! */
249 	if (vcpu_book3s->proto_vsid_next == vcpu_book3s->proto_vsid_max) {
250 		vcpu_book3s->proto_vsid_next = vcpu_book3s->proto_vsid_first;
251 		memset(vcpu_book3s->sid_map, 0,
252 		       sizeof(struct kvmppc_sid_map) * SID_MAP_NUM);
253 		kvmppc_mmu_pte_flush(vcpu, 0, 0);
254 		kvmppc_mmu_flush_segments(vcpu);
255 	}
256 
257 	if (mmu_has_feature(MMU_FTR_68_BIT_VA))
258 		vsid_bits = VSID_BITS_256M;
259 
260 	map->host_vsid = vsid_scramble(vcpu_book3s->proto_vsid_next++,
261 				       VSID_MULTIPLIER_256M, vsid_bits);
262 
263 	map->guest_vsid = gvsid;
264 	map->valid = true;
265 
266 	trace_kvm_book3s_slb_map(sid_map_mask, gvsid, map->host_vsid);
267 
268 	return map;
269 }
270 
kvmppc_mmu_next_segment(struct kvm_vcpu * vcpu,ulong esid)271 static int kvmppc_mmu_next_segment(struct kvm_vcpu *vcpu, ulong esid)
272 {
273 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
274 	int i;
275 	int max_slb_size = 64;
276 	int found_inval = -1;
277 	int r;
278 
279 	/* Are we overwriting? */
280 	for (i = 0; i < svcpu->slb_max; i++) {
281 		if (!(svcpu->slb[i].esid & SLB_ESID_V))
282 			found_inval = i;
283 		else if ((svcpu->slb[i].esid & ESID_MASK) == esid) {
284 			r = i;
285 			goto out;
286 		}
287 	}
288 
289 	/* Found a spare entry that was invalidated before */
290 	if (found_inval >= 0) {
291 		r = found_inval;
292 		goto out;
293 	}
294 
295 	/* No spare invalid entry, so create one */
296 
297 	if (mmu_slb_size < 64)
298 		max_slb_size = mmu_slb_size;
299 
300 	/* Overflowing -> purge */
301 	if ((svcpu->slb_max) == max_slb_size)
302 		kvmppc_mmu_flush_segments(vcpu);
303 
304 	r = svcpu->slb_max;
305 	svcpu->slb_max++;
306 
307 out:
308 	svcpu_put(svcpu);
309 	return r;
310 }
311 
kvmppc_mmu_map_segment(struct kvm_vcpu * vcpu,ulong eaddr)312 int kvmppc_mmu_map_segment(struct kvm_vcpu *vcpu, ulong eaddr)
313 {
314 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
315 	u64 esid = eaddr >> SID_SHIFT;
316 	u64 slb_esid = (eaddr & ESID_MASK) | SLB_ESID_V;
317 	u64 slb_vsid = SLB_VSID_USER;
318 	u64 gvsid;
319 	int slb_index;
320 	struct kvmppc_sid_map *map;
321 	int r = 0;
322 
323 	slb_index = kvmppc_mmu_next_segment(vcpu, eaddr & ESID_MASK);
324 
325 	if (vcpu->arch.mmu.esid_to_vsid(vcpu, esid, &gvsid)) {
326 		/* Invalidate an entry */
327 		svcpu->slb[slb_index].esid = 0;
328 		r = -ENOENT;
329 		goto out;
330 	}
331 
332 	map = find_sid_vsid(vcpu, gvsid);
333 	if (!map)
334 		map = create_sid_map(vcpu, gvsid);
335 
336 	map->guest_esid = esid;
337 
338 	slb_vsid |= (map->host_vsid << 12);
339 	slb_vsid &= ~SLB_VSID_KP;
340 	slb_esid |= slb_index;
341 
342 #ifdef CONFIG_PPC_64K_PAGES
343 	/* Set host segment base page size to 64K if possible */
344 	if (gvsid & VSID_64K)
345 		slb_vsid |= mmu_psize_defs[MMU_PAGE_64K].sllp;
346 #endif
347 
348 	svcpu->slb[slb_index].esid = slb_esid;
349 	svcpu->slb[slb_index].vsid = slb_vsid;
350 
351 	trace_kvm_book3s_slbmte(slb_vsid, slb_esid);
352 
353 out:
354 	svcpu_put(svcpu);
355 	return r;
356 }
357 
kvmppc_mmu_flush_segment(struct kvm_vcpu * vcpu,ulong ea,ulong seg_size)358 void kvmppc_mmu_flush_segment(struct kvm_vcpu *vcpu, ulong ea, ulong seg_size)
359 {
360 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
361 	ulong seg_mask = -seg_size;
362 	int i;
363 
364 	for (i = 0; i < svcpu->slb_max; i++) {
365 		if ((svcpu->slb[i].esid & SLB_ESID_V) &&
366 		    (svcpu->slb[i].esid & seg_mask) == ea) {
367 			/* Invalidate this entry */
368 			svcpu->slb[i].esid = 0;
369 		}
370 	}
371 
372 	svcpu_put(svcpu);
373 }
374 
kvmppc_mmu_flush_segments(struct kvm_vcpu * vcpu)375 void kvmppc_mmu_flush_segments(struct kvm_vcpu *vcpu)
376 {
377 	struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
378 	svcpu->slb_max = 0;
379 	svcpu->slb[0].esid = 0;
380 	svcpu_put(svcpu);
381 }
382 
kvmppc_mmu_destroy_pr(struct kvm_vcpu * vcpu)383 void kvmppc_mmu_destroy_pr(struct kvm_vcpu *vcpu)
384 {
385 	kvmppc_mmu_hpte_destroy(vcpu);
386 	__destroy_context(to_book3s(vcpu)->context_id[0]);
387 }
388 
kvmppc_mmu_init_pr(struct kvm_vcpu * vcpu)389 int kvmppc_mmu_init_pr(struct kvm_vcpu *vcpu)
390 {
391 	struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
392 	int err;
393 
394 	err = hash__alloc_context_id();
395 	if (err < 0)
396 		return -1;
397 	vcpu3s->context_id[0] = err;
398 
399 	vcpu3s->proto_vsid_max = ((u64)(vcpu3s->context_id[0] + 1)
400 				  << ESID_BITS) - 1;
401 	vcpu3s->proto_vsid_first = (u64)vcpu3s->context_id[0] << ESID_BITS;
402 	vcpu3s->proto_vsid_next = vcpu3s->proto_vsid_first;
403 
404 	kvmppc_mmu_hpte_init(vcpu);
405 
406 	return 0;
407 }
408